bims-auttor Biomed News
on Autophagy and mTOR
Issue of 2023‒04‒16
sixty-four papers selected by
Viktor Korolchuk, Newcastle University
  1. LC3B is a cofactor for LMX1B-mediated transcription of autophagy genes in dopaminergic neurons.
  2. Genome-wide CRISPR screens identify ILF3 as a mediator of mTORC1-dependent amino acid sensing.
  3. The Role of Alternative Mitophagy in Heart Disease.
  4. STING recruits WIPI2 for autophagosome formation.
  5. The emerging roles of autophagy in intestinal epithelial cells and its links to inflammatory bowel disease.
  6. Transcriptional regulation of autophagy by chromatin remodeling complex and histone variant.
  7. Transcriptional regulation of autophagy and its implications in human disease.
  8. ApoM Activates Autophagy and Suppresses Lyosomal Lethargy to Combat Doxorubicin Cardiomyopathy.
  9. Iron Limitation Restores Autophagy and Increases Lifespan in the Yeast Model of Niemann-Pick Type C1.
  10. A regulatory circuit comprising the CBP and SIRT7 regulates FAM134B-mediated ER-phagy.
  11. Inhibiting autophagy before it starts.
  12. Translatome analysis of Tuberous Sclerosis Complex-1 patient-derived neural progenitor cells reveal rapamycin-dependent and independent alterations.
  13. AUTOPHAGY IN THE EYE: FROM PHYSIOLOGY TO PATHOPHYSOLOGY.
  14. Mechanosensitive mTORC1 signaling maintains lymphatic valves.
  15. Targeting mTOR for Anti-Aging and Anti-Cancer Therapy.
  16. PTEN-induced kinase PINK1 supports colorectal cancer growth by regulating the labile iron pool.
  17. Rapamycin Alleviates Protein Aggregates, Reduces Neuroinflammation, and Rescues Demyelination in Globoid Cell Leukodystrophy.
  18. Transcriptomic Changes Predict Metabolic Alterations in LC3 Associated Phagocytosis in Aged Mice.
  19. NR3C1/Glucocorticoid receptor activation promotes pancreatic β-cell autophagy overload in response to glucolipotoxicity.
  20. Light Chain Amyloidosis-Induced Autophagy Is Mediated by the Foxo3a/Beclin-1 Pathway in Cardiomyocytes.
  21. The SFTSV Nonstructural Proteins Induce Autophagy to Promote Viral Replication via Interaction with Vimentin.
  22. The active zone protein Clarinet regulates synaptic sorting of ATG-9 and presynaptic autophagy.
  23. Oxygen modulates iron homeostasis by switching iron-sensing of NCOA4.
  24. ATG5 provides host protection acting as a switch in the atg8ylation cascade between autophagy and secretion.
  25. Copper metabolism in cell death and autophagy.
  26. The interaction between Hsp90-mediated unfolded protein response and autophagy contributes to As3+/ Se4+ combination-induced apoptosis of acute promyelocytic leukemia cells.
  27. Atractylenolide III Ameliorated Autophagy Dysfunction via Epidermal Growth Factor Receptor-Mammalian Target of Rapamycin Signals and Alleviated Silicosis Fibrosis in Mice.
  28. Inhibition of NLRP1 inflammasome improves autophagy dysfunction and Aβ disposition in APP/PS1 mice.
  29. Atmospheric PM2.5 induce autophagy and autophagic flux blockage in HUVEC cells via ROS/TXNIP signaling: Important role of metal components.
  30. Activation of AMPK promotes cardiac differentiation by stimulating the autophagy pathway.
  31. Autophagy: A Potential Therapeutic Target to Tackle Drug Resistance in Multiple Myeloma.
  32. Cobalt induces neurodegeneration through FTO-triggered autophagy impairment by targeting TSC1 in an m6A-YTHDF2-dependent manner.
  33. Early Alterations of RNA Binding Protein (RBP) Homeostasis and ER Stress-Mediated Autophagy Contributes to Progressive Retinal Degeneration in the rd10 Mouse Model of Retinitis Pigmentosa (RP).
  34. Mitophagy in metabolic syndrome.
  35. The Role of Rab Proteins in Mitophagy: Insights into Neurodegenerative Diseases.
  36. De novo missense variants in RRAGC lead to a fatal mTORopathy of early childhood.
  37. Structural mechanisms of mitochondrial quality control mediated by PINK1 and parkin.
  38. Melatonin ameliorates glyphosate- and hard water-induced renal tubular epithelial cell senescence via PINK1-Parkin-dependent mitophagy.
  39. The hunger strikes back: an epigenetic memory for autophagy.
  40. The spectrum of cell death in sarcoma.
  41. PAK4-relevant proliferation reduced by cell autophagy via p53/mTOR/p-AKT signaling.
  42. Proteostasis and lysosomal quality control deficits in Alzheimer's disease neurons.
  43. Parkin increases the risk of colitis by downregulation of VDR via autophagy-lysosome degradation.
  44. Molecular milieu of autophagy in cervical cancer and its therapeutic implications.
  45. Beclin-1-dependent autophagy, but not apoptosis, is critical for stem-cell-mediated endometrial programming and the establishment of pregnancy.
  46. Cancer Cell-Derived PDGFB Stimulates mTORC1 Activation in Renal Carcinoma.
  47. Mitophagy, Inflammasomes and Their Interaction in Kidney Diseases: A Comprehensive Review of Experimental Studies.
  48. Lysosomal chloride transporter CLH-6 protects lysosome membrane integrity via cathepsin activation.
  49. The dual role of autophagy in periprosthetic osteolysis.
  50. A prolyl oligopeptidase inhibitor reduces tau pathology in cellular models and in mice with tauopathy.
  51. Autophagy restricts Mycobacterium tuberculosis during acute infection in mice.
  52. Heterozygous Cc2d1a mice show sex-dependent changes in the Beclin-1/p62 ratio with impaired prefrontal cortex and hippocampal autophagy.
  53. Melatonin protects against developmental PBDE-47 neurotoxicity by targeting the AMPK/mitophagy axis.
  54. Hydroxytyrosol Interference with Inflammaging via Modulation of Inflammation and Autophagy.
  55. Effect of N-acetyl-l-cysteine on Cell Phenotype and Autophagy in Pichia pastoris Expressing Human Serum Albumin and Porcine Follicle-Stimulating Hormone Fusion Protein.
  56. Glycyrrhizin, an inhibitor of HMGB1 induces autolysosomal degradation function and inhibits Helicobacter pylori infection.
  57. Genetic Evidence for Endolysosomal Dysfunction in Parkinson's Disease: A Critical Overview.
  58. SGLT2 inhibitors and autophagy in diabetes.
  59. LTF Induces Radioresistance by Promoting Autophagy and Forms an AMPK/SP2/NEAT1/miR-214-5p Feedback Loop in Lung Squamous Cell Carcinoma.
  60. Fluorescence Assays for Real-Time Tracking of Cell Surface Protein Internalization and Endosomal Sorting in Axons of Primary Mouse Hippocampal Neurons.
  61. Maternal obesity and offspring health: Adapting metabolic changes through autophagy and mitophagy.
  62. Hyperglycemia Aggravates Periodontitis via Autophagy Impairment and ROS-Inflammasome-Mediated Macrophage Pyroptosis.
  63. Pharmacological Targeting of Bcl-2 Induces Caspase 3-Mediated Cleavage of HDAC6 and Regulates the Autophagy Process in Colorectal Cancer.
  64. Apolipoprotein M Attenuates Anthracycline Cardiotoxicity and Lysosomal Injury.
  1. J Cell Biol. 2023 May 01. pii: e202303008. [Epub ahead of print]222(5):
    LC3B is a cofactor for LMX1B-mediated transcription of autophagy genes in dopaminergic neurons.
    Athanasios Kournoutis, Terje Johansen.
      It is becoming increasingly clear that the Atg8 family of autophagy proteins have roles not only in the cytoplasm, but also in the cell nucleus. In this issue, Jiménez-Moreno et al. (2023. J. Cell Biol.https://doi.org/10.1083/jcb.201910133) report that nuclear LC3B binds to the LIM homeodomain transcription factor LMX1B and acts as a cofactor for LMX1B-mediated transcription of autophagy genes, providing stress protection and ensuring survival of midbrain dopaminergic neurons.
    DOI:  https://doi.org/10.1083/jcb.202303008
  2. Nat Cell Biol. 2023 Apr 10.
    Genome-wide CRISPR screens identify ILF3 as a mediator of mTORC1-dependent amino acid sensing.
    Guokai Yan, Jinxin Yang, Wen Li, Ao Guo, Jialiang Guan, Ying Liu.
      The mechanistic target of rapamycin complex 1 (mTORC1) is an essential hub that integrates nutrient signals and coordinates metabolism to control cell growth. Amino acid signals are detected by sensor proteins and relayed to the GATOR2 and GATOR1 complexes to control mTORC1 activity. Here we perform genome-wide CRISPR/Cas9 screens, coupled with an assay for mTORC1 activity based on fluorescence-activated cell sorting analysis of pS6, to identify potential regulators of mTORC1-dependent amino acid sensing. We then focus on interleukin enhancer binding factor 3 (ILF3), one of the candidate genes from the screen. ILF3 tethers the GATOR complexes to lysosomes to control mTORC1. Adding a lysosome-targeting sequence to the GATOR2 component WDR24 bypasses the requirement for ILF3 to modulate amino-acid-dependent mTORC1 signalling. ILF3 plays an evolutionarily conserved role in human and mouse cells, and in worms to regulate the mTORC1 pathway, control autophagy activity and modulate the ageing process.
    DOI:  https://doi.org/10.1038/s41556-023-01123-x
  3. Int J Mol Sci. 2023 Mar 28. pii: 6362. [Epub ahead of print]24(7):
    The Role of Alternative Mitophagy in Heart Disease.
    Jihoon Nah.
      Autophagy is essential for maintaining cellular homeostasis through bulk degradation of subcellular constituents, including misfolded proteins and dysfunctional organelles. It is generally governed by the proteins Atg5 and Atg7, which are critical regulators of the conventional autophagy pathway. However, recent studies have identified an alternative Atg5/Atg7-independent pathway, i.e., Ulk1- and Rab9-mediated alternative autophagy. More intensive studies have identified its essential role in stress-induced mitochondrial autophagy, also known as mitophagy. Alternative mitophagy plays pathophysiological roles in heart diseases such as myocardial ischemia and pressure overload. Here, this review discusses the established and emerging mechanisms of alternative autophagy/mitophagy that can be applied in therapeutic interventions for heart disorders.
    Keywords:  Rab9; alternative autophagy; conventional autophagy; heart disease; mitophagy
    DOI:  https://doi.org/10.3390/ijms24076362
  4. Autophagy. 2023 Apr 13. 1-2
    STING recruits WIPI2 for autophagosome formation.
    Wei Wan, Wei Liu.
      Induction of autophagy is a primordial function of the cGAS-STING pathway. However, the molecular mechanisms regulating autophagosome formation during STING-induced autophagy remain largely unknown. Recently, we reported that STING directly interacts with WIPI2 to recruit WIPI2 onto STING-positive vesicles for LC3 lipidation and autophagosome formation. We found that STING and PtdIns3P competitively bind to the FRRG motif of WIPI2, resulting in a mutual inhibition between STING-induced and PtdIns3P-dependent autophagy. We also showed that STING-WIPI2 interaction is necessary for cells to clear cytoplasmic DNA and attenuate activated cGAS-STING signaling. In summary, by identifying the interaction between STING and WIPI2, our study revealed a mechanism that allows STING to bypass the canonical upstream machinery to induce autophagosome formation.Abbreviations: ATG: autophagy-related; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; cGAMP: cyclic GMP-AMP; cGAS: cyclic GMP-AMP synthase; ER: endoplasmic reticulum; ERGIC: ER-Golgi intermediate compartment; IRF3: interferon regulatory factor 3; PtdIns3P: phosphatidylinositol-3-phosphate; SQSTM1: sequestosome 1; STING: stimulator of interferon genes; TBK1: TANK-binding kinase 1; ULK1: unc-51 like autophagy activating kinase 1; WIPI2: WD repeat domain, phosphoinositide interacting 2.
    Keywords:  Autophagosome; STING; WIPI2; autophagy; cGAS
    DOI:  https://doi.org/10.1080/15548627.2023.2202108
  5. Biochem Soc Trans. 2023 Apr 13. pii: BST20221300. [Epub ahead of print]
    The emerging roles of autophagy in intestinal epithelial cells and its links to inflammatory bowel disease.
    Sharon Tran, Juliani Juliani, W Douglas Fairlie, Erinna F Lee.
      Landmark genome-wide association studies (GWAS) identified that mutations in autophagy genes correlated with inflammatory bowel disease (IBD), a heterogenous disease characterised by prolonged inflammation of the gastrointestinal tract, that can reduce a person's quality of life. Autophagy, the delivery of intracellular components to the lysosome for degradation, is a critical cellular housekeeping process that removes damaged proteins and turns over organelles, recycling their amino acids and other constituents to supply cells with energy and necessary building blocks. This occurs under both basal and challenging conditions such as nutrient deprivation. An understanding of the relationship between autophagy, intestinal health and IBD aetiology has improved over time, with autophagy having a verified role in the intestinal epithelium and immune cells. Here, we discuss research that has led to an understanding that autophagy genes, including ATG16L, ATG5, ATG7, IRGM, and Class III PI3K complex members, contribute to innate immune defence in intestinal epithelial cells (IECs) via selective autophagy of bacteria (xenophagy), how autophagy contributes to the regulation of the intestinal barrier via cell junctional proteins, and the critical role of autophagy genes in intestinal epithelial secretory subpopulations, namely Paneth and goblet cells. We also discuss how intestinal stem cells can utilise autophagy. Importantly, mouse studies have provided evidence that autophagy deregulation has serious physiological consequences including IEC death and intestinal inflammation. Thus, autophagy is now established as a key regulator of intestinal homeostasis. Further research into how its cytoprotective mechanisms can prevent intestinal inflammation may provide insights into the effective management of IBD.
    Keywords:  Crohns disease; autophagy; disease; gastrointestinal physiology; homeostasis; molecular basis of health and disease
    DOI:  https://doi.org/10.1042/BST20221300
  6. Autophagy. 2023 Apr 13. 1-3
    Transcriptional regulation of autophagy by chromatin remodeling complex and histone variant.
    Xin Li, Shanshan Wang, Xilan Yu, Shanshan Li.
      Autophagy is a catabolic process to maintain homeostasis, and involved in cell differentiation and development. Autophagy is tightly regulated in response to nutrient availability but the underlying mechanism is not completely understood. Recently, we identified the chromatin remodeling complex INO80 (inositol-requiring mutant 80) and histone variant H2A.Z as new autophagy regulators and uncover how histone deacetylase Rpd3L (reduced potassium dependency 3 large) complex represses autophagy by deacetylating Ino80 and H2A.Z. In particular, Rpd3L complex deacetylates Ino80 at lysine 929, which protects Ino80 from being degraded by autophagy. The stabilized Ino80 then evicts H2A.Z from autophagy-related (ATG) genes, leading to their transcriptional repression. In parallel, Rpd3L complex also deacetylates H2A.Z, which further reduces its association with ATG gene promoters and repress ATG gene transcription. Under nutrient-rich conditions, Rpd3L-mediated deacetylation of Ino80 K929 and H2A.Z is enhanced by the TORC1 complex (target of rapamycin complex 1). Under nitrogen-starvation condition, TORC1 is inactivated, leading to reduced activity of Rpd3L complex and increased acetylation of Ino80 and H2A.Z, which in turn induce the transcription of ATG genes. These results reveal a critical role of chromatin remodelers and histone variants in regulating autophagy in response to nutrient availability.Abbreviations: INO80: inositol-requiring mutant 80; Rpd3: reduced potassium dependency 3; H2A.Z: histone H2A variant; Rpd3L complex: Rpd3 large complex; H4K16: H4 lysine 16; H3R17: H3 arginine 17; H3T11: H3 threonine 11; TORC1 complex: target of rapamycin complex 1; ATG: autophagy-related; SWI/SNF: switch/sucrose non-fermentable; SWR1: Swi2/Snf2-related ATPase complex; RSC: remodel the structure of chromatin; ISWI: imitation switch; CHD1: chromodomain helicase DNA binding protein 1; Arp8: actin-related protein 8; Sds3: suppressor of defective silencing 3; Ume6: unscheduled meiotic gene expression 6.
    Keywords:  Ino80; Rpd3; autophagy; chromatin remodeling complex; histone variant; transcriptional regulation
    DOI:  https://doi.org/10.1080/15548627.2023.2200352
  7. Cell Death Differ. 2023 Apr 12.
    Transcriptional regulation of autophagy and its implications in human disease.
    Yuchen Lei, Daniel J Klionsky.
      Macroautophagy/autophagy is a conserved catabolic pathway that is vital for maintaining cell homeostasis and promoting cell survival under stressful conditions. Dysregulation of autophagy is associated with a variety of human diseases, such as cancer, neurodegenerative diseases, and metabolic disorders. Therefore, this pathway must be precisely regulated at multiple levels, involving epigenetic, transcriptional, post-transcriptional, translational, and post-translational mechanisms, to prevent inappropriate autophagy activity. In this review, we focus on autophagy regulation at the transcriptional level, summarizing the transcription factors that control autophagy gene expression in both yeast and mammalian cells. Because the expression and/or subcellular localization of some autophagy transcription factors are altered in certain diseases, we also discuss how changes in transcriptional regulation of autophagy are associated with human pathophysiologies.
    DOI:  https://doi.org/10.1038/s41418-023-01162-9
  8. JACC Basic Transl Sci. 2023 Mar;8(3): 356-358
    ApoM Activates Autophagy and Suppresses Lyosomal Lethargy to Combat Doxorubicin Cardiomyopathy.
    Felipe Kazmirczak, Kurt W Prins.
      
    Keywords:  anthracycline; apolipoprotein M; autophagy; heart failure; lysosome
    DOI:  https://doi.org/10.1016/j.jacbts.2022.10.003
  9. Int J Mol Sci. 2023 Mar 25. pii: 6221. [Epub ahead of print]24(7):
    Iron Limitation Restores Autophagy and Increases Lifespan in the Yeast Model of Niemann-Pick Type C1.
    Telma S Martins, Rafaela S Costa, Rita Vilaça, Carolina Lemos, Vitor Teixeira, Clara Pereira, Vítor Costa.
      Niemann-Pick type C1 (NPC1) is an endolysosomal transmembrane protein involved in the export of cholesterol and sphingolipids to other cellular compartments such as the endoplasmic reticulum and plasma membrane. NPC1 loss of function is the major cause of NPC disease, a rare lysosomal storage disorder characterized by an abnormal accumulation of lipids in the late endosomal/lysosomal network, mitochondrial dysfunction, and impaired autophagy. NPC phenotypes are conserved in yeast lacking Ncr1, an orthologue of human NPC1, leading to premature aging. Herein, we performed a phosphoproteomic analysis to investigate the effect of Ncr1 loss on cellular functions mediated by the yeast lysosome-like vacuoles. Our results revealed changes in vacuolar membrane proteins that are associated mostly with vesicle biology (fusion, transport, organization), autophagy, and ion homeostasis, including iron, manganese, and calcium. Consistently, the cytoplasm to vacuole targeting (Cvt) pathway was increased in ncr1∆ cells and autophagy was compromised despite TORC1 inhibition. Moreover, ncr1∆ cells exhibited iron overload mediated by the low-iron sensing transcription factor Aft1. Iron deprivation restored the autophagic flux of ncr1∆ cells and increased its chronological lifespan and oxidative stress resistance. These results implicate iron overload on autophagy impairment, oxidative stress sensitivity, and cell death in the yeast model of NPC1.
    Keywords:  Aft1; Ncr1; TORC1; autophagy; chronological aging; iron; oxidative stress; vacuoles; vesicle trafficking
    DOI:  https://doi.org/10.3390/ijms24076221
  10. J Cell Biol. 2023 May 01. pii: e202201068. [Epub ahead of print]222(5):
    A regulatory circuit comprising the CBP and SIRT7 regulates FAM134B-mediated ER-phagy.
    Xinyi Wang, Xiao Jiang, Boran Li, Jiahua Zheng, Jiansheng Guo, Lei Gao, Mengjie Du, Xialian Weng, Lin Li, She Chen, Jingzi Zhang, Lei Fang, Ting Liu, Liang Wang, Wei Liu, Dante Neculai, Qiming Sun.
      Macroautophagy (autophagy) utilizes a serial of receptors to specifically recognize and degrade autophagy cargoes, including damaged organelles, to maintain cellular homeostasis. Upstream signals spatiotemporally regulate the biological functions of selective autophagy receptors through protein post-translational modifications (PTM) such as phosphorylation. However, it is unclear how acetylation directly controls autophagy receptors in selective autophagy. Here, we report that an ER-phagy receptor FAM134B is acetylated by CBP acetyltransferase, eliciting intense ER-phagy. Furthermore, FAM134B acetylation promoted CAMKII-mediated phosphorylation to sustain a mode of milder ER-phagy. Conversely, SIRT7 deacetylated FAM134B to temper its activities in ER-phagy to avoid excessive ER degradation. Together, this work provides further mechanistic insights into how ER-phagy receptor perceives environmental signals for fine-tuning of ER homeostasis and demonstrates how nucleus-derived factors are programmed to control ER stress by modulating ER-phagy.
    DOI:  https://doi.org/10.1083/jcb.202201068
  11. Autophagy. 2023 Apr 10. 1-2
    Inhibiting autophagy before it starts.
    Yuqi Lin, Biao Yu, Pengfei Fang, Jing Wang.
      Autophagy, an important cellular stress response mechanism, is often exploited by a variety of cancer cells to sustain rapid growth under stresses such as nutrient deprivation and hypoxia. Autophagy also plays a key role in tumor resistance to chemotherapy, radiotherapy or targeted therapy. Inhibition of autophagy is therefore a promising tumor treatment strategy. However, there is still a lack of effective autophagy inhibitors suitable for clinical use. Most drug development has focused on enzymes like the VPS34 and ULK1 kinases, or the cysteine protease ATG4B, which plays different roles in autophagy. We discovered a drug molecule Eltrombopag that inhibits the expression of autophagic lysosomal genes at the stage of transcriptional level, where the synthesis of these proteins has not really begun, by directly inhibiting the TFEB (transcription factor EB). This drug can improve the therapeutic effect of Temozolomide on glioblastoma treatment, further confirming the value of inhibiting autophagy in the treatment of cancer.Abbreviation: VPS34: vacuolar protein sorting 34; ULK1: unc-51 like autophagy activating kinase 1; TFEB: transcription factor EB; MITF: microphthalmia-associated transcription factor; TFE3: transcription factor E3; EO: Eltrombopag; ITC: isothermal titration calorimetry; bHLH-LZ: basic helix-loop-helix leucine zipper; LAMP1: lysosomal-associated membrane protein 1; CTSF: cathepsin F; HEXA: hexosaminidase subunit alpha.
    Keywords:  Autophagy inhibition; Eltrombopag; cancer therapy; glioblastoma; the transcription factor EB (TFEB)
    DOI:  https://doi.org/10.1080/15548627.2023.2197364
  12. Res Sq. 2023 Mar 27. pii: rs.3.rs-2702044. [Epub ahead of print]
    Translatome analysis of Tuberous Sclerosis Complex-1 patient-derived neural progenitor cells reveal rapamycin-dependent and independent alterations.
    Inci Aksoylu, Pauline Martin, Francis Robert, Krzysztof Szkop, Nicholas Redmond, Shan Chen, Roberta Beauchamp, Irene Nobeli, Jerry Pelletier, Ola Larsson, Vijaya Ramesh.
      Tuberous sclerosis complex (TSC) is an inherited neurocutaneous disorder caused by mutations in TSC1 or TSC2 genes, with patients often exhibiting neurodevelopmental (ND) manifestations termed TSC-associated neuropsychiatric disorders (TAND) including autism spectrum disorder (ASD). The hamartin-tuberin (TSC1-TSC2) protein complex inactivates mechanistic target of rapamycin complex 1 (mTORC1) signaling, leading to increased protein synthesis via inactivation of translational repressor eIF4E-binding proteins (4E-BPs). In TSC1 -null neural progenitor cells (NPCs), we previously reported early ND phenotypic changes, including increased proliferation/altered neurite outgrowth, which were unaffected by mTORC1-inhibitor rapamycin. Here, using polysome-profiling to quantify translational efficiencies at a transcriptome-wide level, we observed numerous TSC1-dependent alterations in NPCs, largely recapitulated in post-mortem brains from ASD donors. Although rapamycin partially reversed TSC1-associated alterations, most neural activity/synaptic- or ASD-related genes remained insensitive but were inhibited by third-generation bi-steric, mTORC1-selective inhibitor RMC-6272, which also reversed altered ND phenotypes. Together these data reveal potential implications for treatment of TAND.
    DOI:  https://doi.org/10.21203/rs.3.rs-2702044/v1
  13. Autophagy Rep. 2023 ;pii: 2178996. [Epub ahead of print]2(1):
    AUTOPHAGY IN THE EYE: FROM PHYSIOLOGY TO PATHOPHYSOLOGY.
    Paloma B Liton, Kathleen Boesze-Battaglia, Michael E Boulton, Patricia Boya, Thomas A Ferguson, Ian G Ganley, Anu Kauppinnen, Gordon W Laurie, Noboru Mizushima, Hideaki Morishita, Rossella Russo, Jaya Sadda, Rajalekshmy Shyam, Debasish Sinha, Debra A Thompson, David N Zacks.
      Autophagy is a catabolic self-degradative pathway that promotes the degradation and recycling of intracellular material through the lysosomal compartment. Although first believed to function in conditions of nutritional stress, autophagy is emerging as a critical cellular pathway, involved in a variety of physiological and pathophysiological processes. Autophagy dysregulation is associated with an increasing number of diseases, including ocular diseases. On one hand, mutations in autophagy-related genes have been linked to cataracts, glaucoma, and corneal dystrophy; on the other hand, alterations in autophagy and lysosomal pathways are a common finding in essentially all diseases of the eye. Moreover, LC3-associated phagocytosis, a form of non-canonical autophagy, is critical in promoting visual cycle function. This review collects the latest understanding of autophagy in the context of the eye. We will review and discuss the respective roles of autophagy in the physiology and/or pathophysiology of each of the ocular tissues, its diurnal/circadian variation, as well as its involvement in diseases of the eye.
    Keywords:  AMD; RGC; RPE; autophagy; cataracts; cornea; corneal dystrophy; dry eye; eye; eye diseases; glaucoma; lens; lysosomes; outflow pathway; photoreceptors; retina; retinal detachment; retinal epithelial cells; retinal ganglion cells; retinitis pigmentosa; trabecular meshwork; vision cycle
    DOI:  https://doi.org/10.1080/27694127.2023.2178996
  14. J Cell Biol. 2023 Jun 05. pii: e202207049. [Epub ahead of print]222(6):
    Mechanosensitive mTORC1 signaling maintains lymphatic valves.
    Cansaran Saygili Demir, Amélie Sabine, Muyun Gong, Olivier Dormond, Tatiana V Petrova.
      Homeostatic maintenance and repair of lymphatic vessels are essential for health. We investigated the dynamics and the molecular mechanisms of lymphatic endothelial cell (LEC) renewal in adult mesenteric quiescent lymphatic vasculature using label-retention, lineage tracing, and cell ablation strategies. Unlike during development, adult LEC turnover and proliferation was confined to the valve regions of collecting vessels, with valve cells displaying the shortest lifespan. Proliferating valve sinus LECs were the main source for maintenance and repair of lymphatic valves. We identified mechanistic target of rapamycin complex 1 (mTORC1) as a mechanoresponsive pathway activated by fluid shear stress in LECs. Depending on the shear stress level, mTORC1 activity drives division of valve cells or dictates their mechanic resilience through increased protein synthesis. Overactivation of lymphatic mTORC1 in vivo promoted supernumerary valve formation. Our work provides insights into the molecular mechanisms of maintenance of healthy lymphatic vascular system.
    DOI:  https://doi.org/10.1083/jcb.202207049
  15. Molecules. 2023 Apr 01. pii: 3157. [Epub ahead of print]28(7):
    Targeting mTOR for Anti-Aging and Anti-Cancer Therapy.
    Wencheng Fu, Geng Wu.
      The balance between anabolism and catabolism is disrupted with aging, with the rate of anabolism being faster than that of catabolism. Therefore, mTOR, whose major function is to enhance anabolism and inhibit catabolism, has become a potential target of inhibition for anti-aging therapy. Interestingly, it was found that the downregulation of the mTOR signaling pathway had a lifespan-extending effect resembling calorie restriction. In addition, the mTOR signaling pathway promotes cell proliferation and has been regarded as a potential anti-cancer target. Rapamycin and rapalogs, such as everolimus, have proven to be effective in preventing certain tumor growth. Here, we reviewed the basic knowledge of mTOR signaling, including both mTORC1 and mTORC2. Then, for anti-aging, we cited a lot of evidence to discuss the role of targeting mTOR and its anti-aging mechanism. For cancer therapy, we also discussed the role of mTOR signaling in different types of cancers, including idiopathic pulmonary fibrosis, tumor immunity, etc. In short, we discussed the research progress and both the advantages and disadvantages of targeting mTOR in anti-aging and anti-cancer therapy. Hopefully, this review may promote more ideas to be generated for developing inhibitors of mTOR signaling to fight cancer and extend lifespan.
    Keywords:  aging; anti-aging; anti-cancer therapy; cancer; mTOR; mTOR inhibition; senescence
    DOI:  https://doi.org/10.3390/molecules28073157
  16. J Biol Chem. 2023 Apr 08. pii: S0021-9258(23)00333-2. [Epub ahead of print] 104691
    PTEN-induced kinase PINK1 supports colorectal cancer growth by regulating the labile iron pool.
    Brandon Chen, Nupur K Das, Indrani Talukder, Rashi Singhal, Cristina Castillo, Anthony Andren, Joseph D Mancias, Costas A Lyssiotis, Yatrik M Shah.
      Mitophagy is a cargo-specific autophagic process that recycles damaged mitochondria to promote mitochondrial turnover. PTEN-induced putative kinase 1 (PINK1) mediates the canonical mitophagic pathway. However, the role of PINK1 in diseases where mitophagy has been purported to play a role, such as colorectal cancer, in unclear.Our results here demonstrate that higher PINK1 expression is positively correlated with decreased colon cancer survival, and mitophagy is required for colon cancer growth following nutrient stress. We show that doxycycline-inducible knockdown (KD) of PINK1 in a panel of colon cancer cell lines inhibited proliferation, whereas disruption of other mitophagy receptors did not impact cell growth. We observed that PINK KD led to a decrease in mitochondrial respiration, membrane hyperpolarization, accumulation of mitochondrial DNA, and depletion of antioxidant glutathione. In addition, mitochondria are important hubs for the utilization of iron and synthesizing iron-dependent cofactors such as heme and iron sulfur clusters. We observed an increase in the iron storage protein ferritin and a decrease labile iron pool in the PINK1 KD cells, but total cellular iron or markers of iron starvation/overload were not affected. Finally, cellular iron storage and the labile iron pool are maintained via autophagic degradation of ferritin (ferritinophagy). We found overexpressing nuclear receptor coactivator 4, a key adaptor for ferritinophagy, rescued cell growth and the labile iron pool in PINK1 KD cells. These results indicate that PINK1 integrates mitophagy and ferritinophagy to regulate intracellular iron availability and is essential for maintaining intracellular iron homeostasis to support survival and growth in colorectal cancer cells.
    Keywords:  colon cancer; ferritinophagy; iron; mitochondria; mitophagy
    DOI:  https://doi.org/10.1016/j.jbc.2023.104691
  17. Cells. 2023 Mar 24. pii: 993. [Epub ahead of print]12(7):
    Rapamycin Alleviates Protein Aggregates, Reduces Neuroinflammation, and Rescues Demyelination in Globoid Cell Leukodystrophy.
    Dar-Shong Lin, Yu-Wen Huang, Tsung-Han Lee, Lung Chang, Zon-Darr Huang, Tsu-Yen Wu, Tuan-Jen Wang, Che-Sheng Ho.
      We have shown in vivo and in vitro previously that psychosine causes dysfunction of autophagy and the ubiquitin-proteasome system underlying the pathogenesis of globoid cell leukodystrophy (GLD), a devastating lysosomal storage disease complicated by global demyelination. Here, we investigated the therapeutic efficacy of the mTOR inhibitor rapamycin in twitcher mice, a murine model of infantile GLD, in biochemical, histochemical, and clinical aspects. Administration of rapamycin to twitcher mice inhibited mTOR signaling in the brains, and significantly reduced the accumulation of insoluble ubiquitinated protein and the formation of ubiquitin aggregates. The astrocytes and microglia reactivity were attenuated in that reactive astrocytes, ameboid microglia, and globoid cells were reduced in the brains of rapamycin-treated twitcher mice. Furthermore, rapamycin improved the cortical myelination, neurite density, and rescued the network complexity in the cortex of twitcher mice. The therapeutic action of rapamycin on the pathology of the twitcher mice's brains prolonged the longevity of treated twitcher mice. Overall, these findings validate the therapeutic efficacy of rapamycin and highlight enhancing degradation of aggregates as a therapeutic strategy to modulate neuroinflammation, demyelination, and disease progression of GLD and other leukodystrophies associated with intracellular aggregates.
    Keywords:  Krabbe disease; autophagy; demyelination; globoid cell leukodystrophy; neuroinflammation; psychosine; ubiquitin-proteasome system
    DOI:  https://doi.org/10.3390/cells12070993
  18. Int J Mol Sci. 2023 Apr 04. pii: 6716. [Epub ahead of print]24(7):
    Transcriptomic Changes Predict Metabolic Alterations in LC3 Associated Phagocytosis in Aged Mice.
    Anuradha Dhingra, John W Tobias, Nancy J Philp, Kathleen Boesze-Battaglia.
      LC3b (Map1lc3b) plays an essential role in canonical autophagy and is one of several components of the autophagy machinery that mediates non-canonical autophagic functions. Phagosomes are often associated with lipidated LC3b to promote phagosome maturation in a process called LC3-associated phagocytosis (LAP). Specialized phagocytes, such as mammary epithelial cells, retinal pigment epithelial (RPE) cells, and sertoli cells, utilize LAP for optimal degradation of phagocytosed material, including debris. In the visual system, LAP is critical to maintain retinal function, lipid homeostasis, and neuroprotection. In a mouse model of retinal lipid steatosis-mice lacking LC3b (LC3b-/-), we observed increased lipid deposition, metabolic dysregulation, and enhanced inflammation. Herein, we present a non-biased approach to determine if loss of LAP mediated processes modulate the expression of various genes related to metabolic homeostasis, lipid handling, and inflammation. A comparison of the RPE transcriptome of WT and LC3b-/- mice revealed 1533 DEGs, with ~73% upregulated and 27% downregulated. Enriched gene ontology (GO) terms included inflammatory response (upregulated DEGs), fatty acid metabolism, and vascular transport (downregulated DEGs). Gene set enrichment analysis (GSEA) identified 34 pathways; 28 were upregulated (dominated by inflammation/related pathways) and 6 were downregulated (dominated by metabolic pathways). Analysis of additional gene families identified significant differences for genes in the solute carrier family, RPE signature genes, and genes with a potential role in age-related macular degeneration. These data indicate that loss of LC3b induces robust changes in the RPE transcriptome contributing to lipid dysregulation and metabolic imbalance, RPE atrophy, inflammation, and disease pathophysiology.
    Keywords:  LC3-associated phagocytosis (LAP); cholesterol metabolism; cholesterol trafficking; fatty acid metabolism; inflammation; monocarboxylate transporters; peroxisomes; retinal pigment epithelium (RPE); transcriptomics
    DOI:  https://doi.org/10.3390/ijms24076716
  19. Autophagy. 2023 Apr 11.
    NR3C1/Glucocorticoid receptor activation promotes pancreatic β-cell autophagy overload in response to glucolipotoxicity.
    Tijun Wu, Yixue Shao, Xirui Li, Tao Wu, Ling Yu, Jin Liang, Yaru Zhang, Jiahui Wang, Tong Sun, Yunxia Zhu, Xiaoai Chang, Shusen Wang, Fang Chen, Xiao Han.
      Diabetes is a complex and heterogeneous disorder characterized by chronic hyperglycemia. Its core cause is progressively impaired insulin secretion by pancreatic β-cell failures, usually upon a background of pre-existing insulin resistance. Recent studies demonstrate that macroautophagy/autophagy is essential to maintain architecture and function of β-cells, whereas excessive autophagy is also involved in β-cell dysfunction and death. It has been poorly understood whether autophagy plays a protective or harmful role in β-cells, while we report here that it is dependent on NR3C1/glucocorticoid receptor activation. We proved that deleterious hyperactive autophagy happened only upon NR3C1 activation in β-cells under glucolipotoxic conditions, which eventually promoted diabetes. The transcriptome and the N6-methyladenosine (m6A) methylome revealed that NR3C1-enhancement upregulated the RNA demethylase FTO (fat mass and obesity associated) protein in β-cells, which caused diminished m6A modifications on mRNAs of four core Atg (autophagy related) genes (Atg12, Atg5, Atg16l2, Atg9a) and, hence, hyperactive autophagy and defective insulin output; by contrast, FTO inhibition, achieved by the specific FTO inhibitor Dac51, prevented NR3C1-instigated excessive autophagy activation. Importantly, Dac51 effectively alleviated impaired insulin secretion and glucose intolerance in hyperglycemic β-cell specific NR3C1 overexpression mice. Our results determine that the NR3C1-FTO-m6A modifications-Atg genes axis acts as a key mediator of balanced autophagic flux in pancreatic β-cells, which offers a novel therapeutic target for the treatment of diabetes.
    Keywords:  Autophagy; FTO; NR3C1; diabetes; m6A; pancreatic β-cell
    DOI:  https://doi.org/10.1080/15548627.2023.2200625
  20. Lab Invest. 2023 02;pii: S0023-6837(22)00001-0. [Epub ahead of print]103(2): 100001
    Light Chain Amyloidosis-Induced Autophagy Is Mediated by the Foxo3a/Beclin-1 Pathway in Cardiomyocytes.
    Yuan Zhang, Wanpeng Yu, Wenguang Chang, Man Wang, Lei Zhang, Fei Yu.
      Cardiac amyloidosis is a disease in which the extracellular space of the heart is deposited with and infiltrated by amyloid fibrillar material, and light chain (LC) amyloidosis (AL) is the most serious form of the disease. AL is caused by the overproduction and aggregation of monoclonal immunoglobulin LCs produced by bone marrow plasma cells. Studies have shown that the initial response at a subcellular level to the toxicity of AL is lysosomal dysfunction with impaired autophagy, elevated reactive oxygen species, cellular dysfunction, and cellular death. Therefore, we speculate that the multiple myeloma complicated by cardiac amyloidosis is due to the deposition of λ LC fibrils in cardiomyocytes, leading to dysregulation of autophagy and cell death. We constructed BACN1 siRNA or FOXO3A siRNA and transfected them into H9c2 cells. We detected changes in oxidative stress- and autophagy-related markers. Our results show that monoclonal immunoglobulin λ LCs can form amyloid aggregates, which are cytotoxic to cardiomyocytes. λ LC fibrils deposit on the cell surface, causing oxidative stress and excessive autophagy by increasing Beclin-1 expression and the LC3 II/LC3 I ratio and decreasing p62 expression, ultimately inducing cell death. Beclin-1 knockdown reversed the increase in the LC3 II/LC3 I ratio and the decrease in p62 induced by LC fibrils, while suppressing overactivated autophagy and oxidative stress. Furthermore, LCs reduce the expression of p-Foxo3a (Ser253) (inactive) and promote Foxo3a translocation into the nucleus to perform transcriptional activity, which induces autophagy-related gene overexpression. Silencing Foxo3a can suppress excessive autophagy induced by LC fibrils and protect cells from death. In summary, the results showed that the cytotoxicity of amyloid fibrils formed by λ LCs on cardiomyocytes is triggered by excessive autophagy and is mediated through the Foxo3a/Beclin-1 pathway.
    Keywords:  autophagy; cardiac amyloidosis; light chain amyloidosis
    DOI:  https://doi.org/10.1016/j.labinv.2022.100001
  21. J Virol. 2023 Apr 11. e0030223
    The SFTSV Nonstructural Proteins Induce Autophagy to Promote Viral Replication via Interaction with Vimentin.
    Sihua Liu, Yazhi Su, Zhuozhuang Lu, Xiaohui Zou, Leling Xu, Yue Teng, Zhiyun Wang, Tao Wang.
      Severe fever with thrombocytopenia syndrome virus (SFTSV) is a newly identified phlebovirus associated with severe hemorrhagic fever in humans. Studies have shown that SFTSV nucleoprotein (N) induces BECN1-dependent autophagy to promote viral assembly and release. However, the function of other SFTSV proteins in regulating autophagy has not been reported. In this study, we identify SFTSV NSs, a nonstructural protein that forms viroplasm-like structures in the cytoplasm of infected cells as the virus component mediating SFTSV-induced autophagy. We found that SFTSV NSs-induced autophagy was inclusion body independent, and most phenuivirus NSs had autophagy-inducing effects. Unlike N protein-induced autophagy, SFTSV NSs was key in regulating autophagy by interacting with the host's vimentin in an inclusion body-independent manner. NSs interacted with vimentin and induced vimentin degradation through the K48-linked ubiquitin-proteasome pathway. This negatively regulating Beclin1-vimentin complex formed and promoted autophagy. Furthermore, we identified the NSs-binding domain of vimentin and found that overexpression of wild-type vimentin antagonized the induced effect of NSs on autophagy and inhibited viral replication, suggesting that vimentin is a potential antiviral target. The present study shows a novel mechanism through which SFTSV nonstructural protein activates autophagy, which provides new insights into the role of NSs in SFTSV infection and pathogenesis. IMPORTANCE Severe fever with thrombocytopenia syndrome virus (SFTSV) is a newly emerging tick-borne pathogen that causes multifunctional organ failure and even death in humans. As a housekeeping mechanism for cells to maintain steady state, autophagy plays a dual role in viral infection and the host's immune response. However, the relationship between SFTSV infection and autophagy has not been described in detail yet. Here, we demonstrated that SFTSV infection induced complete autophagic flux and facilitated viral proliferation. We also identified a key mechanism underlying NSs-induced autophagy, in which NSs interacted with vimentin to inhibit the formation of the Beclin1-vimentin complex and induced vimentin degradation through K48-linked ubiquitination modification. These findings may help us understand the new functions and mechanisms of NSs and may aid in the identification of new antiviral targets.
    Keywords:  Beclin1-vimentin complex; IBs; NSs; SFTSV; autophagy
    DOI:  https://doi.org/10.1128/jvi.00302-23
  22. PLoS Biol. 2023 Apr;21(4): e3002030
    The active zone protein Clarinet regulates synaptic sorting of ATG-9 and presynaptic autophagy.
    Zhao Xuan, Sisi Yang, Benjamin Clark, Sarah E Hill, Laura Manning, Daniel A Colón-Ramos.
      Autophagy is essential for cellular homeostasis and function. In neurons, autophagosome biogenesis is temporally and spatially regulated to occur near presynaptic sites, in part via the trafficking of autophagy transmembrane protein ATG-9. The molecules that regulate autophagy by sorting ATG-9 at synapses remain largely unknown. Here, we conduct forward genetic screens at single synapses of C. elegans neurons and identify a role for the long isoform of the active zone protein Clarinet (CLA-1L) in regulating sorting of autophagy protein ATG-9 at synapses, and presynaptic autophagy. We determine that disrupting CLA-1L results in abnormal accumulation of ATG-9 containing vesicles enriched with clathrin. The ATG-9 phenotype in cla-1(L) mutants is not observed for other synaptic vesicle proteins, suggesting distinct mechanisms that regulate sorting of ATG-9-containing vesicles and synaptic vesicles. Through genetic analyses, we uncover the adaptor protein complexes that genetically interact with CLA-1 in ATG-9 sorting. We also determine that CLA-1L extends from the active zone to the periactive zone and genetically interacts with periactive zone proteins in ATG-9 sorting. Our findings reveal novel roles for active zone proteins in the sorting of ATG-9 and in presynaptic autophagy.
    DOI:  https://doi.org/10.1371/journal.pbio.3002030
  23. J Biol Chem. 2023 Apr 12. pii: S0021-9258(23)00343-5. [Epub ahead of print] 104701
    Oxygen modulates iron homeostasis by switching iron-sensing of NCOA4.
    Sota Kuno, Kazuhiro Iwai.
      To ensure proper utilization of iron and avoid its toxicity, cells are equipped with iron-sensing proteins to maintain cellular iron homeostasis. We showed previously that NCOA4, a ferritin-specific autophagy adapter, intricately regulates the fate of ferritin; upon binding to Fe3+, NCOA4 forms insoluble condensates and regulates ferritin autophagy in iron-replete conditions. Here, we demonstrate an additional iron-sensing mechanism of NCOA4. Our results indicate that the insertion of an Fe-S cluster enables preferential recognition of NCOA4 by the HERC2 ubiquitin ligase in iron-replete conditions, resulting in degradation by the proteasome and subsequent inhibition of ferritinophagy. We also found that both condensation and ubiquitin-mediated degradation of NCOA4 can occur in the same cell, and the cellular oxygen tension determines the selection of these pathways. Fe-S cluster-mediated degradation of NCOA4 is enhanced under hypoxia, whereas NCOA4 forms condensates and degrades ferritin at higher oxygen levels. Considering the involvement of iron in oxygen handling, our findings demonstrate that the NCOA4/ferritin axis is another layer of cellular iron regulation in response to oxygen levels.
    Keywords:  autophagy; ferritin; hypoxia; iron metabolism; iron-sulfur protein
    DOI:  https://doi.org/10.1016/j.jbc.2023.104701
  24. Dev Cell. 2023 Apr 10. pii: S1534-5807(23)00130-2. [Epub ahead of print]
    ATG5 provides host protection acting as a switch in the atg8ylation cascade between autophagy and secretion.
    Fulong Wang, Ryan Peters, Jingyue Jia, Michal Mudd, Michelle Salemi, Lee Allers, Ruheena Javed, Thabata L A Duque, Masroor A Paddar, Einar S Trosdal, Brett Phinney, Vojo Deretic.
      ATG5 is a part of the E3 ligase directing lipidation of ATG8 proteins, a process central to membrane atg8ylation and canonical autophagy. Loss of Atg5 in myeloid cells causes early mortality in murine models of tuberculosis. This in vivo phenotype is specific to ATG5. Here, we show using human cell lines that absence of ATG5, but not of other ATGs directing canonical autophagy, promotes lysosomal exocytosis and secretion of extracellular vesicles and, in murine Atg5fl/fl LysM-Cre neutrophils, their excessive degranulation. This is due to lysosomal disrepair in ATG5 knockout cells and the sequestration by an alternative conjugation complex, ATG12-ATG3, of ESCRT protein ALIX, which acts in membrane repair and exosome secretion. These findings reveal a previously undescribed function of ATG5 in its host-protective role in murine experimental models of tuberculosis and emphasize the significance of the branching aspects of the atg8ylation conjugation cascade beyond the canonical autophagy.
    Keywords:  ATG5; ESCRT; SARS-CoV-2; atg8ylation; autophagy; coronavirus; exosomes; lysosome; neutrophils; tuberculosis
    DOI:  https://doi.org/10.1016/j.devcel.2023.03.014
  25. Autophagy. 2023 Apr 13.
    Copper metabolism in cell death and autophagy.
    Qian Xue, Rui Kang, Daniel J Klionsky, Daolin Tang, Jinbao Liu, Xin Chen.
      Copper is an essential trace element in biological systems, maintaining the activity of enzymes and the function of transcription factors. However, at high concentrations, copper ions show increased toxicity by inducing regulated cell death, such as apoptosis, paraptosis, pyroptosis, ferroptosis, and cuproptosis. Furthermore, copper ions can trigger macroautophagy/autophagy, a lysosome-dependent degradation pathway that plays a dual role in regulating the survival or death fate of cells under various stress conditions. Pathologically, impaired copper metabolism due to environmental or genetic causes is implicated in a variety of human diseases, such as rare Wilson disease and common cancers. Therapeutically, copper-based compounds are potential chemotherapeutic agents that can be used alone or in combination with other drugs or approaches to treat cancer. Here, we review the progress made in understanding copper metabolic processes and their impact on the regulation of cell death and autophagy. This knowledge may help in the design of future clinical tools to improve cancer diagnosis and treatment.
    Keywords:  Apoptosis; autophagy; cancer; cell death; copper; cuproptosis; ferroptosis; paraptosis; pyroptosis
    DOI:  https://doi.org/10.1080/15548627.2023.2200554
  26. Toxicol Appl Pharmacol. 2023 Apr 07. pii: S0041-008X(23)00150-3. [Epub ahead of print]467 116511
    The interaction between Hsp90-mediated unfolded protein response and autophagy contributes to As3+/ Se4+ combination-induced apoptosis of acute promyelocytic leukemia cells.
    Jiayin Chang, Shihai Yan, Zhirong Geng, Zhilin Wang.
      The interaction between the unfolded protein response (UPR) and autophagy plays either pro-survival or pro-apoptotic roles in the treatment of acute promyelocytic leukemia (APL). Our previous study has shown that the combination therapy of arsenite (As3+) and selenite (Se4+) induces apoptosis in APL NB4 cells, although the mechanisms are not clear. Here, we demonstrate that the interaction between heat shock protein 90 (Hsp90)-mediated UPR and autophagy is the core module for As3+/Se4+ combination-induced apoptosis. Hsp90 overexpression and knockdown assays indicate that Hsp90 inhibition by PERK modulates two branches of the UPR, leading to the activation of ATF4 and CHOP, causing the degradation of IRE1α and the dephosphorylation of eIF2α, thereby contributing to switching the cytoprotective UPR into an apoptotic pathway. Assays using pretreatment with inducers and inhibitors of endoplasmic reticulum stress (ERS) and autophagy reveal that autophagy is stimulated by ERS but suppressed by As3+/Se4+ combination via the mTOR signaling pathway. However, inhibition of autophagy decreases GRP78 expression and eIF2α phosphorylation, thereby further promoting ERS-induced apoptosis. Moreover, As3+/Se4+ combination blocks hepatic infiltration in an APL-NCG mouse model of extramedullary infiltration. Taken together, these findings provide novel agents and therapeutic approaches for APL.
    Keywords:  Acute promyelocytic leukemia; As(3+)/Se(4+) combination; Autophagy; Extramedullary infiltration; Heat shock protein 90; Unfolded protein response
    DOI:  https://doi.org/10.1016/j.taap.2023.116511
  27. Lab Invest. 2023 02;pii: S0023-6837(22)00087-3. [Epub ahead of print]103(2): 100024
    Atractylenolide III Ameliorated Autophagy Dysfunction via Epidermal Growth Factor Receptor-Mammalian Target of Rapamycin Signals and Alleviated Silicosis Fibrosis in Mice.
    Shiyi Tan, Shang Yang, Huimin Kang, Ke Zhou, Hanqin Wang, Yujing Zhang, Shi Chen.
      Atractylenolide III (ATL-III) is a major active constituent of the natural plant Atractylodes rhizome. Our previous study has shown that ATL-III may alleviate alveolar macrophage apoptosis via the inhibition of the mammalian target of rapamycin (mTOR)-mediated autophagy of human silicosis. Therefore, we aimed to further explore the function of ATL-III in autophagy, apoptosis, and pulmonary fibrosis by establishing the ATL-III-intervened silicosis mouse model in this study. Meanwhile, we sought and then verified potential autophagy-related signaling pathways by matching differentially expressed genes (attained by RNA sequencing) and the autophagy database. In this study, RNA-sequencing results implied that the epidermal growth factor receptor, the crucial upstream activator of mTOR, was seen as a potential autophagy-regulatory molecule in the ATL-III-intervened silicosis mouse model. The finding of this study was that ATL-III might improve the disorder of autophagic degradation via the activation of epidermal growth factor receptor-mTOR signals in the pulmonary tissue of the silicosis mouse model. ATL-III also alleviated cell apoptosis and silicotic fibrosis. Overall, we supposed that ATL-III might be a potential protective medicine, which had a regulatory effect on autophagy, for the intervention of silicotic fibrosis. In the future, the therapeutic drugs for silicosis should be further focused on the development and application of such natural autophagy agents.
    Keywords:  EGFR-mTOR axis; atractylenolide III; autophagy; silicosis
    DOI:  https://doi.org/10.1016/j.labinv.2022.100024
  28. Behav Brain Funct. 2023 Apr 13. 19(1): 7
    Inhibition of NLRP1 inflammasome improves autophagy dysfunction and Aβ disposition in APP/PS1 mice.
    Xuewang Li, Han Zhang, Liu Yang, Xianan Dong, Yuli Han, Yong Su, Weiping Li, Weizu Li.
      Increasing evidence has shown that the NOD-like receptor protein 1 (NLRP1) inflammasome is associated with Aβ generation and deposition, which contributes to neuronal damage and neuronal-inflammation in Alzheimer's disease (AD). However, the specific mechanism of NLRP1 inflammasome in the pathogenesis of AD is still unclear. It has been reported that autophagy dysfunction can aggravate the pathological symptoms of AD and plays an important role in regulating Aβ generation and clearance. We hypothesized that NLRP1 inflammasome activation may induce autophagy dysfunction contributing to the progression of AD. In the present study, we observed the relationship between Aβ generation and NLRP1 inflammasome activation, as well as AMPK/mTOR mediated-autophagy dysfunction in WT 9-month-old (M) mice, APP/PS1 6 M and APP/PS1 9 M mice. Additionally, we further studied the effect of NLRP1 knockdown on cognitive function, Aβ generation, neuroinflammation and AMPK/mTOR mediated autophagy in APP/PS1 9 M mice. Our results indicated that NLRP1 inflammasome activation and AMPK/mTOR mediated-autophagy dysfunction are closely implicated in Aβ generation and deposition in APP/PS1 9 M mice, but not in APP/PS1 6 M mice. Meanwhile, we found that knockdown of NLRP1 significantly improved learning and memory impairments, decreased the expressions of NLRP1, ASC, caspase-1, p-NF-κB, IL-1β, APP, CTF-β, BACE1 and Aβ1-42, and decreased the level of p-AMPK, Beclin 1 and LC3 II, and increased the level of p-mTOR and P62 in APP/PS1 9 M mice. Our study suggested that inhibition of NLRP1 inflammasome activation improves AMPK/mTOR mediated-autophagy dysfunction, resulting in the decrease of Aβ generation, and NLRP1 and autophagy might be important targets to delay the progression of AD.
    Keywords:  AMPK/mTOR; APP/PS1 mice; Alzheimer's disease; Autophagy; NLRP1 inflammasome
    DOI:  https://doi.org/10.1186/s12993-023-00209-8
  29. J Hazard Mater. 2023 Mar 05. pii: S0304-3894(22)02419-0. [Epub ahead of print]445 130623
    Atmospheric PM2.5 induce autophagy and autophagic flux blockage in HUVEC cells via ROS/TXNIP signaling: Important role of metal components.
    Yan-Yang Lu, Meiyi Cao, Fuping Li, Meiping Tian, Hongyun Ren, Qiaoqiao Chi, Qingyu Huang.
      Autophagy was involved in vascular endothelial injury caused by PM2.5, which aggravated the pathogenesis of cardiovascular diseases. However, major toxic components and underlying mechanism responsible for PM2.5-induced autophagy remain unclear. In this study, the effects of water-extracted PM2.5 (WE-PM2.5) on autophagy in human umbilical vein endothelial cells (HUVEC) were studied. Our results showed WE-PM2.5 promoted autophagosome initiation and formation, meanwhile, lysosomal function was impaired, which further caused autophagic flux blockage in HUVEC cells. Furthermore, removal of metals alleviated WE-PM2.5-induced autophagic flux blockage, while the artificial metal mixture reproduced the WE-PM2.5 response. Mechanistically, ROS regulated autophagy-related proteins evidenced by BECN1, LC3B and p62 expression reversed by NAC pretreatment in WE-PM2.5-exposed cells. WE-PM2.5 also increased TXNIP expression mediated by ROS; moreover, knockdown of TXNIP in WE-PM2.5-exposed cells decreased BECN1 and LC3B expression, but had little effects on the expression of p62, CTSB, and CTSD, indicating WE-PM2.5-induced TXNIP was involved in autophagosome initiation and formation rather than autophagic degradation. Collectively, WE-PM2.5-induced ROS not only promoted autophagosome initiation and formation, but also inhibited autophagic degradation. However, as the downstream molecule of ROS, TXNIP was only involved in autophagosome initiation and formation. Importantly, WE-PM2.5-bound metals were largely responsible for autophagic flux blockage in HUVEC cells.
    Keywords:  Autophagy; Lysosome; Metals; Thioredoxin-interacting protein (TXNIP); Water-extracted PM(2.5) (WE-PM(2.5))
    DOI:  https://doi.org/10.1016/j.jhazmat.2022.130623
  30. J Cell Commun Signal. 2023 Apr 11.
    Activation of AMPK promotes cardiac differentiation by stimulating the autophagy pathway.
    Mina Kolahdouzmohammadi, Sara Pahlavan, Fattah Sotoodehnejadnematalahi, Yaser Tahamtani, Mehdi Totonchi.
      Autophagy, a critical catabolic process for cell survival against different types of stress, has a role in the differentiation of various cells, such as cardiomyocytes. Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) is an energy-sensing protein kinase involved in the regulation of autophagy. In addition to its direct role in regulating autophagy, AMPK can also influence other cellular processes by regulating mitochondrial function, posttranslational acetylation, cardiomyocyte metabolism, mitochondrial autophagy, endoplasmic reticulum stress, and apoptosis. As AMPK is involved in the control of various cellular processes, it can influence the health and survival of cardiomyocytes. This study investigated the effects of an AMPK inducer (Metformin) and an autophagy inhibitor (Hydroxychloroquine) on the differentiation of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs). The results showed that autophagy was upregulated during cardiac differentiation. Furthermore, AMPK activation increased the expression of CM-specific markers in hPSC-CMs. Additionally, autophagy inhibition impaired cardiomyocyte differentiation by targeting autophagosome-lysosome fusion. These results indicate the significance of autophagy in cardiomyocyte differentiation. In conclusion, AMPK might be a promising target for the regulation of cardiomyocyte generation by in vitro differentiation of pluripotent stem cells.
    Keywords:  AMPK; Autophagy; Cardiomyocyte differentiation; Hydroxychloroquine; Metformin
    DOI:  https://doi.org/10.1007/s12079-023-00744-z
  31. Int J Mol Sci. 2023 Mar 23. pii: 6019. [Epub ahead of print]24(7):
    Autophagy: A Potential Therapeutic Target to Tackle Drug Resistance in Multiple Myeloma.
    Hamed Bashiri, Hossein Tabatabaeian.
      Multiple myeloma (MM) is the second most prevalent hematologic malignancy. In the past few years, the survival of MM patients has increased due to the emergence of novel drugs and combination therapies. Nevertheless, one of the significant obstacles in treating most MM patients is drug resistance, especially for individuals who have experienced relapses or developed resistance to such cutting-edge treatments. One of the critical processes in developing drug resistance in MM is autophagic activity, an intracellular self-digestive process. Several possible strategies of autophagy involvement in the induction of MM-drug resistance have been demonstrated thus far. In multiple myeloma, it has been shown that High mobility group box protein 1 (HMGB1)-dependent autophagy can contribute to drug resistance. Moreover, activation of autophagy via proteasome suppression induces drug resistance. Additionally, the effectiveness of clarithromycin as a supplemental drug in treating MM has been reported recently, in which autophagy blockage is proposed as one of the potential action mechanisms of CAM. Thus, a promising therapeutic approach that targets autophagy to trigger the death of MM cells and improve drug susceptibility could be considered. In this review, autophagy has been addressed as a survival strategy crucial for drug resistance in MM.
    Keywords:  autophagy; drug resistance; multiple myeloma
    DOI:  https://doi.org/10.3390/ijms24076019
  32. J Hazard Mater. 2023 Apr 06. pii: S0304-3894(23)00637-4. [Epub ahead of print]453 131354
    Cobalt induces neurodegeneration through FTO-triggered autophagy impairment by targeting TSC1 in an m6A-YTHDF2-dependent manner.
    Jianping Tang, Fuli Zheng, Xu Liu, Yanjun Li, Zhenkun Guo, Xinpei Lin, Jinfu Zhou, Yu Zhang, Guangxia Yu, Hong Hu, Wenya Shao, Siying Wu, Huangyuan Li.
      Cobalt is the most widely used heavy metal pollutant in medicine and industry. Excessive cobalt exposure can adversely affect human health. Neurodegenerative symptoms have been observed in cobalt-exposed populations; however, the underlying mechanisms remain largely unknown. In this study, we demonstrate that the N6-methyladenosine (m6A) demethylase fat mass and obesity-associated gene (FTO) mediates cobalt-induced neurodegeneration by impairing autophagic flux. Cobalt-induced neurodegeneration was exacerbated through FTO genetic knockdown or repression of demethylase activity, but was alleviated by FTO overexpression. Mechanistically, we showed that FTO regulates TSC1/2-mTOR signaling pathway by targeting TSC1 mRNA stability in an m6A-YTHDF2 manner, which resulted in autophagosome accumulation. Furthermore, FTO decreases lysosome-associated membrane protein-2 (LAMP2) to inhibit the integration of autophagosomes and lysosomes, leading to autophagic flux damage. In vivo experiments further identified that central nervous system (CNS)-Fto-specific knockout resulted in serious neurobehavioral and pathological damage as well as TSC1-related autophagy impairment in cobalt-exposed mice. Interestingly, FTO-regulated autophagy impairment has been confirmed in patients with hip replacement. Collectively, our results provide novel insights into m6A-modulated autophagy through FTO-YTHDF2 targeted TSC1 mRNA stability, revealing cobalt is a novel epigenetic hazard that induces neurodegeneration. These findings suggest the potential therapeutic targets for hip replacement in patients with neurodegenerative damage.
    Keywords:  Autophagic flux; Cobalt chloride; Epigenetic hazard; MRNA stability; Neurodegenerative damage
    DOI:  https://doi.org/10.1016/j.jhazmat.2023.131354
  33. Cells. 2023 Apr 06. pii: 1094. [Epub ahead of print]12(7):
    Early Alterations of RNA Binding Protein (RBP) Homeostasis and ER Stress-Mediated Autophagy Contributes to Progressive Retinal Degeneration in the rd10 Mouse Model of Retinitis Pigmentosa (RP).
    Alfred Yamoah, Priyanka Tripathi, Haihong Guo, Leonie Scheve, Peter Walter, Sandra Johnen, Frank Müller, Joachim Weis, Anand Goswami.
      The retinal degeneration 10 (rd10) mouse model is widely used to study retinitis pigmentosa (RP) pathomechanisms. It offers a rather unique opportunity to study trans-neuronal degeneration because the cell populations in question are separated anatomically and the mutated Pde6b gene is selectively expressed in rod photoreceptors. We hypothesized that RNA binding protein (RBP) aggregation and abnormal autophagy might serve as early pathogenic events, damaging non-photoreceptor retinal cell types that are not primarily targeted by the Pde6b gene defect. We used a combination of immunohistochemistry (DAB, immunofluorescence), electron microscopy (EM), subcellular fractionation, and Western blot analysis on the retinal preparations obtained from both rd10 and wild-type mice. We found early, robust increases in levels of the protective endoplasmic reticulum (ER) calcium (Ca2+) buffering chaperone Sigma receptor 1 (SigR1) together with other ER-Ca2+ buffering proteins in both photoreceptors and non-photoreceptor neuronal cells before any noticeable photoreceptor degeneration. In line with this, we found markedly altered expression of the autophagy proteins p62 and LC3, together with abnormal ER widening and large autophagic vacuoles as detected by EM. Interestingly, these changes were accompanied by early, prominent cytoplasmic and nuclear aggregation of the key RBPs including pTDP-43 and FET family RBPs and stress granule formation. We conclude that progressive neurodegeneration in the rd10 mouse retina is associated with early disturbances of proteostasis and autophagy, along with abnormal cytoplasmic RBP aggregation.
    Keywords:  ER chaperones; ER-Ca2+ homeostasis; RBP aggregation; autophagy; neurodegeneration; rd10 retina
    DOI:  https://doi.org/10.3390/cells12071094
  34. J Clin Hypertens (Greenwich). 2023 Apr 11.
    Mitophagy in metabolic syndrome.
    Mei-Qi Miao, Yu-Bo Han, Li Liu.
      Metabolic syndrome (MS), a chronic and non-communicable pathological condition, is characterized by a constellation of clinical manifestations including insulin resistance, abdominal adiposity, elevated blood pressure, and perturbations in lipid metabolism. The prevalence of MS has increased dramatically in both developed and developing countries and has now become a truly global problem. Excessive energy intake and concomitant obesity are the main drivers of this syndrome. Mitophagy, in which cells degrade damaged mitochondria through a selective form of autophagy, assumes a crucial position in the regulation of mitochondrial integrity and maintenance. Abnormal mitochondrial quality could result in a spectrum of pathological conditions related to metabolic dysfunction, including metabolic syndrome, cardiovascular ailments, and neoplasms. Recently, there has been a proliferation of research pertaining to the process of mitophagy in the context of MS, and there are various regulatory pathways in MS, including pathways like the ubiquitin-dependent mechanism and receptor-mediated mechanisms, among others. Furthermore, studies have uncovered that the process of mitophagy serves a defensive function in the advancement of Metabolic Syndrome, and inhibition of mitophagy exacerbates the advancement of MS. As a result, the regulation of mitophagy holds great promise as a therapeutic approach in the management of Metabolic Syndrome. In this comprehensive analysis, the authors present a synthesis of the diverse regulatory pathways involved in mitophagy in the context of Metabolic Syndrome, as well as its modes of action in metabolic disorders implicated in the development of MS, Including obesity, insulin resistance (IR), and type 2 diabetes mellitus (T2DM), offering novel avenues for the prophylaxis and therapeutic management of MS.
    Keywords:  MS; insulin resistance; metabolic dysfunction; metabolic syndrome; mitophagy
    DOI:  https://doi.org/10.1111/jch.14650
  35. Int J Mol Sci. 2023 Mar 27. pii: 6268. [Epub ahead of print]24(7):
    The Role of Rab Proteins in Mitophagy: Insights into Neurodegenerative Diseases.
    Adeena Shafique, Martina Brughera, Marta Lualdi, Tiziana Alberio.
      Mitochondrial dysfunction and vesicular trafficking alterations have been implicated in the pathogenesis of several neurodegenerative diseases. It has become clear that pathogenetic pathways leading to neurodegeneration are often interconnected. Indeed, growing evidence suggests a concerted contribution of impaired mitophagy and vesicles formation in the dysregulation of neuronal homeostasis, contributing to neuronal cell death. Among the molecular factors involved in the trafficking of vesicles, Ras analog in brain (Rab) proteins seem to play a central role in mitochondrial quality checking and disposal through both canonical PINK1/Parkin-mediated mitophagy and novel alternative pathways. In turn, the lack of proper elimination of dysfunctional mitochondria has emerged as a possible causative/early event in some neurodegenerative diseases. Here, we provide an overview of major findings in recent years highlighting the role of Rab proteins in dysfunctional mitochondrial dynamics and mitophagy, which are characteristic of neurodegenerative diseases. A further effort should be made in the coming years to clarify the sequential order of events and the molecular factors involved in the different processes. A clear cause-effect view of the pathogenetic pathways may help in understanding the molecular basis of neurodegeneration.
    Keywords:  Ras analog in brain (Rab); mitophagy; neurodegeneration; vesicular trafficking
    DOI:  https://doi.org/10.3390/ijms24076268
  36. Genet Med. 2023 Apr 10. pii: S1098-3600(23)00851-1. [Epub ahead of print] 100838
    De novo missense variants in RRAGC lead to a fatal mTORopathy of early childhood.
    Margot R F Reijnders, Annette Seibt, Melanie Brugger, Ideke J C Lamers, Torsten Ott, Oliver Klaas, Judit Horváth, Ailsa M S Rose, Isabel M Craghill, Theresa Brunet, Elisabeth Graf, Katharina Mayerhanser, Debby Hellebrekers, David Pauck, Eva Neuen-Jacob, Richard J T Rodenburg, Dagmar Wieczorek, Dirk Klee, Ertan Mayatepek, Gertjan Driessen, Robert Bindermann, Luisa Averdunk, Klaus Lohmeier, Margje Sinnema, Alexander P A Stegmann, Ronald Roepman, James A Poulter, Felix Distelmaier.
      INTRODUCTION: Mechanistic target of rapamycin complex 1 (mTORC1) regulates cell growth in response to nutritional status. Central to mTORC1 function is the Rag-GTPase heterodimer. One component of the Rag heterodimer is RagC (Ras-related GTP-binding protein C), which is encoded by the RRAGC gene.MATERIAL AND METHODS: Genetic testing via trio exome sequencing was applied to identify the underlying disease cause in three infants who suffered from dilated cardiomyopathy, hepatopathy and brain abnormalities including pachygyria, polymicrogyria, and septo-optic dysplasia. Studies in patient-derived skin fibroblasts and in a HEK293 cell model were performed to investigate the cellular consequences.
    RESULTS: We identified three de novo missense variants in RRAGC (NM_022157.4: c.269C>A, p.(Thr90Asn), c.353C>T, p.(Pro118Leu), and c.343T>C, p.(Trp115Arg)), which were previously reported as occurring somatically in follicular lymphoma. Studies of patient-derived fibroblasts carrying the p.(Thr90Asn) variant revealed increased cell size as well as dysregulation of mTOR-related p70S6K (ribosomal protein S6 kinase 1) and TFEB (transcription factor EB) signaling. Moreover, subcellular localization of mTOR was decoupled from metabolic state. We confirmed the key-findings for all RRAGC variants described in this study in a HEK293 cell model.
    DISCUSSION: The above results are in line with a constitutive over-activation of the mTORC1 pathway. Our study establishes de novo missense variants in RRAGC as cause of an early-onset mTORopathy with unfavorable prognosis.
    Keywords:  cardiomyopathy; cortical malformation; heart; lysosome; mTORopathy; mitochondrial
    DOI:  https://doi.org/10.1016/j.gim.2023.100838
  37. J Mol Biol. 2023 Apr 11. pii: S0022-2836(23)00152-3. [Epub ahead of print] 168090
    Structural mechanisms of mitochondrial quality control mediated by PINK1 and parkin.
    Jean-François Trempe, Kalle Gehring.
      Parkinson's disease (PD) is the second most common neurodegenerative disease and represents a looming public health crisis as the global population ages. While the etiology of the more common, idiopathic form of the disease remains unknown, the last ten years have seen a breakthrough in our understanding of the genetic forms related to two proteins that regulate a quality control system for the removal of damaged or non-functional mitochondria. Here, we review the structure of these proteins, PINK1, a protein kinase, and parkin, a ubiquitin ligase with an emphasis on the molecular mechanisms responsible for their recognition of dysfunctional mitochondria and control of the subsequent ubiquitination cascade. Recent atomic structures have revealed the basis of PINK1 substrate specificity and the conformational changes responsible for activation of PINK1 and parkin catalytic activity. Progress in understanding the molecular basis of mitochondrial quality control promises to open new avenues for therapeutic interventions in PD.
    DOI:  https://doi.org/10.1016/j.jmb.2023.168090
  38. Ecotoxicol Environ Saf. 2023 Apr 15. pii: S0147-6513(23)00223-3. [Epub ahead of print]255 114719
    Melatonin ameliorates glyphosate- and hard water-induced renal tubular epithelial cell senescence via PINK1-Parkin-dependent mitophagy.
    Lin Zhang, Fan Ding, Xuan Wu, Ruojing Wang, Yi Wan, Jianying Hu, Xiaoyan Zhang, Qing Wu.
      The combination of glyphosate (Gly) and hard water (Hwt) is a suspected risk factor for chronic interstitial nephritis in agricultural communities (CINAC). Accumulated mitochondrial damage and proximal tubular epithelial (PTE) cell senescence have been implicated in CINAC pathogenesis. Melatonin (Mel) has potential mitochondrial function and renoprotective properties, but its role and mechanism in CINAC are unknown. Here, we detected PTE cell senescence and PTEN-induced putative protein kinase 1 (PINK1)-parkin RBR E3 ubiquitin protein ligase (Parkin)-dependent mitophagy in mice orally administered with different doses of Gly combined with Hwt (Gly: 100 mg/kg·bw and 0.7 mg/L; Hwt: 2,500 mg/L CaCO3 and 250 mg/L Ca2+) for different durations (12 and 36 w) using histological examination, transmission electron microscopy (TEM), immunofluorescence (IF) analysis, and immunohistochemistry (IHC), immunoblotting, ELISA and biochemical assays with kits. The same assays were performed after combination treatment with Mdivi-1 (an inhibitor of mitophagy, i.p. 10 mg/kg·bw, twice a week for 12 w) or Mel (i.p. 10 mg/kg·bw, once a day for 12 w) under high-level exposure. Gly combined with Hwt (Gly-Hwt) significantly increased P16-P21-dependent PTE cell senescence, mitochondrial fission and oxidative stress, and activated PINK1-Parkin-mediated mitophagy, accompanied by defective autophagic flux at high doses but unaltered autophagic flux at low doses. Improved senescence occurred after Mdivi-1 administration, suggesting that mitophagy is involved in cellular senescence. Mel significantly decreased senescence induced by Gly-Hwt. Furthermore, PINK1-Parkin-dependent mitophagy and autophagic flux were markedly enhanced, and mitochondrial function was improved, as evidenced by reductions in mitochondrial fission and subsequent oxidative damage. Thus, Gly and Hwt synergistically promote PTE cell senescence through PINK1-Parkin-mediated mitophagy, and Mel exerts renoprotective effects by modulating mitophagy, suggesting therapeutic applications in ageing-related CINAC.
    Keywords:  Glyphosate; Hard water; Melatonin; Mitophagy; PINK1; Senescence
    DOI:  https://doi.org/10.1016/j.ecoenv.2023.114719
  39. Cell Death Differ. 2023 Apr 08.
    The hunger strikes back: an epigenetic memory for autophagy.
    Patricia González-Rodríguez, Jens Füllgrabe, Bertrand Joseph.
      Historical and demographical human cohorts of populations exposed to famine, as well as animal studies, revealed that exposure to food deprivation is associated to lasting health-related effects for the exposed individuals, as well as transgenerational effects in their offspring that affect their diseases' risk and overall longevity. Autophagy, an evolutionary conserved catabolic process, serves as cellular response to cope with nutrient starvation, allowing the mobilization of an internal source of stored nutrients and the production of energy. We review the evidence obtained in multiple model organisms that support the idea that autophagy induction, including through dietary regimes based on reduced food intake, is in fact associated to improved health span and extended lifespan. Thereafter, we expose autophagy-induced chromatin remodeling, such as DNA methylation and histone posttranslational modifications that are known heritable epigenetic marks, as a plausible mechanism for transgenerational epigenetic inheritance of hunger.
    DOI:  https://doi.org/10.1038/s41418-023-01159-4
  40. Biomed Pharmacother. 2023 Apr 07. pii: S0753-3322(23)00471-7. [Epub ahead of print]162 114683
    The spectrum of cell death in sarcoma.
    Elizaveta Belyaeva, Nina Loginova, Brett A Schroeder, Ian S Goldlust, Arbind Acharya, Sandeep Kumar, Peter Timashev, Ilya Ulasov.
      The balance between cell death and cell survival is a highly coordinated process by which cells break down and remove unnecessary or harmful materials in a controlled, highly regulated, and compartmentalized manner. Cell exposure to various stresses, such as oxygen starvation, a lack of nutrients, or exposure to radiation, can initiate autophagy. Autophagy is a carefully orchestrated process with multiple steps, each regulated by specific genes and proteins. Autophagy proteins impact cellular maintenance and cell fate in response to stress, and targeting this process is one of the most promising methods of anti-tumor therapy. It is currently not fully understood how autophagy affects different types of tumor cells, which makes it challenging to predict outcomes when this process is manipulated. In this review, we will explore the mechanisms of autophagy and investigate it as a potential and promising therapeutic target for aggressive sarcomas.
    Keywords:  Apoptosis; Autophagy; Sarcoma; Therapy
    DOI:  https://doi.org/10.1016/j.biopha.2023.114683
  41. Transl Cancer Res. 2023 Mar 31. 12(3): 461-472
    PAK4-relevant proliferation reduced by cell autophagy via p53/mTOR/p-AKT signaling.
    Qing Li, Su-Jie Wang, Wen-Jia Wang, Yu-Cai Ye, Ya-Qin Ling, Ya-Fei Dai.
      Background: P21-activated kinase 4 (PAK4) involves in cell proliferation in cancer and mutually regulates with p53, a molecule is demonstrated to control cell autophagy by mammalian target of rapamycin (mTOR)/protein kinase B (AKT) signaling. Since the signaling exhibits an association with PAK family members in cell autophagy, it implies that PAK4-relevant proliferation may be impacted by autophagy via p53 with a lack of evidence in cancer cells.Methods: In this research, transient and stable PAK4-knockdown human hepatocarcinoma cell lines (HepG2) were constructed by transfection of PAK4-RNA interference (RNAi) plasmid and lentivirus containing PAK4-RNAi plasmid, respectively. We investigated cell proliferation using methyl thiazolyl tetrazolium (MTT) and Cell Counting Kit 8 (CCK8) assays, cell cycle by flow cytometry (FCM) and cell autophagy by monodansylcadaverine (MDC) staining and autophagic biomarker's expression, and detected the expressions of p53, mTOR, phosphorylated-AKT (p-AKT) and AKT by immunofluorescence and western blot to explore the mechanism.
    Results: We successfully constructed transient and stable PAK4-knockdown HepG2 cell lines, and detected dysfunction of the cells' proliferation. An increased expression of p53, as a molecule of cell-cycle-surveillance on G1/S phase, was demonstrated in the cells although the cell cycle blocked at G2/M. And then, we detected increased autophagosome and autophagic biomarker LC3-II, and decreased expressions in p-AKT and mTOR.
    Conclusions: The proliferation is reduced in PAK4-knockdown HepG2 cells, which is relative to not only cell cycle arrest but also cell autophagy, and p53/mTOR/p-AKT signaling involves in the cell progress. The findings provide a new mechanism on PAK4 block in cancer therapy.
    Keywords:  P21-activated kinase 4 (PAK4); autophagy; cell cycle; mammalian target of rapamycin (mTOR); p53
    DOI:  https://doi.org/10.21037/tcr-22-2272
  42. bioRxiv. 2023 Mar 27. pii: 2023.03.27.534444. [Epub ahead of print]
    Proteostasis and lysosomal quality control deficits in Alzheimer's disease neurons.
    Ching-Chieh Chou, Ryan Vest, Miguel A Prado, Joshua Wilson-Grady, Joao A Paulo, Yohei Shibuya, Patricia Moran-Losada, Ting-Ting Lee, Jian Luo, Steven P Gygi, Jeffery W Kelly, Daniel Finley, Marius Wernig, Tony Wyss-Coray, Judith Frydman.
      The role of proteostasis and organelle homeostasis dysfunction in human aging and Alzheimer's disease (AD) remains unclear. Analyzing proteome-wide changes in human donor fibroblasts and their corresponding transdifferentiated neurons (tNeurons), we find aging and AD synergistically impair multiple proteostasis pathways, most notably lysosomal quality control (LQC). In particular, we show that ESCRT-mediated lysosomal repair defects are associated with both sporadic and PSEN1 familial AD. Aging- and AD-linked defects are detected in fibroblasts but highly exacerbated in tNeurons, leading to enhanced neuronal vulnerability, unrepaired lysosomal damage, inflammatory factor secretion and cytotoxicity. Surprisingly, tNeurons from aged and AD donors spontaneously develop amyloid-β inclusions co-localizing with LQC markers, LAMP1/2-positive lysosomes and proteostasis factors; we observe similar inclusions in brain tissue from AD patients and APP-transgenic mice. Importantly, compounds enhancing lysosomal function broadly ameliorate these AD-associated pathologies. Our findings establish cell-autonomous LQC dysfunction in neurons as a central vulnerability in aging and AD pathogenesis.
    DOI:  https://doi.org/10.1101/2023.03.27.534444
  43. Int J Biol Sci. 2023 ;19(5): 1633-1644
    Parkin increases the risk of colitis by downregulation of VDR via autophagy-lysosome degradation.
    Zemeng Ma, Junxian Wu, Yuqing Wu, Xiaomeng Sun, Zebing Rao, Naishuang Sun, Yu Fu, Zaikui Zhang, Jingzhou Li, Mengjun Xiao, Qiang Zeng, Yuxuan Wu, Chenhua Han, Ding Ding, Hongjie Zhang, Hua Yuan, Jing Zhang, Shuo Yang, Yunzi Chen.
      Parkin, an E3 ubiquitin ligase, plays an essential role in mitophagy. Emerging evidence indicates that mitophagy is involved in various processes closely related to immune diseases, including inflammatory bowel diseases (IBD). Here, the authors show that Parkin increases the occurrence of colitis and severe inflammation. Deletion of Parkin resulted in marked reductions in colonic inflammation and exhibited high resistance to DSS-induced colitis. Mechanism investigation indicated that Parkin interacts with Vitamin D receptors (VDR), a critical inhibitory regulator in IBD. Parkin promotes VDR degradation via the p62-related autophagy-lysosome pathway. Comparison of colitis in Parkin-/- and Parkin-/-Vdr-/- mice showed that the protective effect of Parkin deletion against colitis was abolished by VDR deletion. The result suggests that the regulatory effect of Parkin in colitis is a VDR-dependent pathway. Our research provides a new role of Parkin in colitis by downregulating VDR, which provides a potential strategy for treating IBD.
    Keywords:  Parkin; Vitamin D receptors; inflammatory bowel diseases
    DOI:  https://doi.org/10.7150/ijbs.77153
  44. Curr Cancer Drug Targets. 2023 Apr 12.
    Molecular milieu of autophagy in cervical cancer and its therapeutic implications.
    Sneha O Pathak, Sonal M Manohar.
      Cervical cancer is a common death-causing cancer among women in developing countries. Majority of the cases are triggered by persistent infections with high-risk Human Papillomavirus (HPV16 and 18). Metastasis, disease relapse, and drug resistance are common among patients in advanced stages of cancer despite the available therapies. Consequently, new prospective targets are needed for this disease. Autophagy is professed to have implications in cervical cancer progression as well as cancer dormancy. This article reviews the role of autophagy in cervical cancer progression and the modulation of the autophagy pathway by HPV. Further, various therapeutic agents that target autophagy in cervical cancer are discussed.
    Keywords:  anticancer therapy; autophagy; cervical cancer; human papilloma virus; resistance to apoptosis; signaling pathways
    DOI:  https://doi.org/10.2174/1568009623666230412104913
  45. Dev Cell. 2023 Apr 04. pii: S1534-5807(23)00109-0. [Epub ahead of print]
    Beclin-1-dependent autophagy, but not apoptosis, is critical for stem-cell-mediated endometrial programming and the establishment of pregnancy.
    Pooja Popli, Suni Tang, Sangappa B Chadchan, Chandni Talwar, Edmund B Rucker, Xiaoming Guan, Diana Monsivais, John P Lydon, Christina L Stallings, Kelle H Moley, Ramakrishna Kommagani.
      The human endometrium shows a remarkable regenerative capacity that enables cyclical regeneration and remodeling throughout a woman's reproductive life. Although early postnatal uterine developmental cues direct this regeneration, the vital factors that govern early endometrial programming are largely unknown. We report that Beclin-1, an essential autophagy-associated protein, plays an integral role in uterine morphogenesis during the early postnatal period. We show that conditional depletion of Beclin-1 in the uterus triggers apoptosis and causes progressive loss of Lgr5+/Aldh1a1+ endometrial progenitor stem cells, with concomitant loss of Wnt signaling, which is crucial for stem cell renewal and epithelial gland development. Beclin-1 knockin (Becn1 KI) mice with disabled apoptosis exhibit normal uterine development. Importantly, the restoration of Beclin-1-driven autophagy, but not apoptosis, promotes normal uterine adenogenesis and morphogenesis. Together, the data suggest that Beclin-1-mediated autophagy acts as a molecular switch that governs the early uterine morphogenetic program by maintaining the endometrial progenitor stem cells.
    Keywords:  Beclin-1; autophagy; endometrium; morphogenesis; stem cells
    DOI:  https://doi.org/10.1016/j.devcel.2023.03.013
  46. Int J Mol Sci. 2023 Mar 29. pii: 6447. [Epub ahead of print]24(7):
    Cancer Cell-Derived PDGFB Stimulates mTORC1 Activation in Renal Carcinoma.
    Asmaa Y Abuhamad, Nurul Nadia Mohamad Zamberi, Sakari Vanharanta, Siti Nur Hasanah Mohd Yusuf, M Aiman Mohtar, Saiful Effendi Syafruddin.
      Clear cell renal cell carcinoma (ccRCC) is a hypervascular tumor that is characterized by bi-allelic inactivation of the VHL tumor suppressor gene and mTOR signalling pathway hyperactivation. The pro-angiogenic factor PDGFB, a transcriptional target of super enhancer-driven KLF6, can activate the mTORC1 signalling pathway in ccRCC. However, the detailed mechanisms of PDGFB-mediated mTORC1 activation in ccRCC have remained elusive. Here, we investigated whether ccRCC cells are able to secrete PDGFB into the extracellular milieu and stimulate mTORC1 signalling activity. We found that ccRCC cells secreted PDGFB extracellularly, and by utilizing KLF6- and PDGFB-engineered ccRCC cells, we showed that the level of PDGFB secretion was positively correlated with the expression of intracellular KLF6 and PDGFB. Moreover, the reintroduction of either KLF6 or PDGFB was able to sustain mTORC1 signalling activity in KLF6-targeted ccRCC cells. We further demonstrated that conditioned media of PDGFB-overexpressing ccRCC cells was able to re-activate mTORC1 activity in KLF6-targeted cells. In conclusion, cancer cell-derived PDGFB can mediate mTORC1 signalling pathway activation in ccRCC, further consolidating the link between the KLF6-PDGFB axis and the mTORC1 signalling pathway activity in ccRCC.
    Keywords:  CRISPR/Cas9; KLF6; PDGFB; mTOR signalling pathway; renal cancer
    DOI:  https://doi.org/10.3390/ijms24076447
  47. J Inflamm Res. 2023 ;16 1457-1469
    Mitophagy, Inflammasomes and Their Interaction in Kidney Diseases: A Comprehensive Review of Experimental Studies.
    Yulin Wang, Dongxu Song, Lin Tang.
      Mitophagy is an important mechanism for mitochondrial quality control by regulating autophagosome-specific phagocytosis, degradation and clearance of damaged mitochondria, and involved in cell damage and diseases. Inflammasomes are important inflammation-related factors newly discovered in recent years, which are involved in cell innate immunity and inflammatory response, and play an important role in kidney diseases. Based on the current studies, we reviewed the progress of mitophagy, inflammasomes and their interaction in kidney diseases.
    Keywords:  acute kidney injury; chronic kidney disease; diabetic kidney disease; inflammasomes; kidney diseases; mitophagy
    DOI:  https://doi.org/10.2147/JIR.S402290
  48. J Cell Biol. 2023 Jun 05. pii: e202210063. [Epub ahead of print]222(6):
    Lysosomal chloride transporter CLH-6 protects lysosome membrane integrity via cathepsin activation.
    Qianqian Zhang, Yuan Li, Youli Jian, Meijiao Li, Xiaochen Wang.
      Lysosomal integrity is vital for cell homeostasis, but the underlying mechanisms are poorly understood. Here, we identify CLH-6, the C. elegans ortholog of the lysosomal Cl-/H+ antiporter ClC-7, as an important factor for protecting lysosomal integrity. Loss of CLH-6 affects lysosomal degradation, causing cargo accumulation and membrane rupture. Reducing cargo delivery or increasing CPL-1/cathepsin L or CPR-2/cathepsin B expression suppresses these lysosomal defects. Inactivation of CPL-1 or CPR-2, like CLH-6 inactivation, affects cargo digestion and causes lysosomal membrane rupture. Thus, loss of CLH-6 impairs cargo degradation, leading to membrane damage of lysosomes. In clh-6(lf) mutants, lysosomes are acidified as in wild type but contain lower chloride levels, and cathepsin B and L activities are significantly reduced. Cl- binds to CPL-1 and CPR-2 in vitro, and Cl- supplementation increases lysosomal cathepsin B and L activities. Altogether, these findings suggest that CLH-6 maintains the luminal chloride levels required for cathepsin activity, thus facilitating substrate digestion to protect lysosomal membrane integrity.
    DOI:  https://doi.org/10.1083/jcb.202210063
  49. Front Cell Dev Biol. 2023 ;11 1123753
    The dual role of autophagy in periprosthetic osteolysis.
    Zhaoyang Yin, Ge Gong, Xiang Wang, Wei Liu, Bin Wang, Jian Yin.
      Periprosthetic osteolysis (PPO) induced by wear particles is an important cause of aseptic loosening after artificial joint replacement, among which the imbalance of osteogenesis and osteoclastic processes occupies a central position. The cells involved in PPO mainly include osteoclasts (macrophages), osteoblasts, osteocytes, and fibroblasts. RANKL/RANK/OGP axis is a typical way for osteolysis. Autophagy, a mode of regulatory cell death and maintenance of cellular homeostasis, has a dual role in PPO. Although autophagy is activated in various periprosthetic cells and regulates the release of inflammatory cytokines, osteoclast activation, and osteoblast differentiation, its beneficial or detrimental role remains controversy. In particular, differences in the temporal control and intensity of autophagy may have different effects. This article focuses on the role of autophagy in PPO, and expects the regulation of autophagy to become a powerful target for clinical treatment of PPO.
    Keywords:  RANKL; aseptic loosening; autophagy; mitophagy; periprosthetic osteolysis
    DOI:  https://doi.org/10.3389/fcell.2023.1123753
  50. Sci Transl Med. 2023 Apr 12. 15(691): eabq2915
    A prolyl oligopeptidase inhibitor reduces tau pathology in cellular models and in mice with tauopathy.
    Tony S Eteläinen, M Catarina Silva, Johanna K Uhari-Väänänen, Francesca De Lorenzo, Maria H Jäntti, Hengjing Cui, Marta Chavero-Pieres, Tommi Kilpeläinen, Christina Mechtler, Reinis Svarcbahs, Erin Seppälä, Juha R Savinainen, Elena Puris, Gert Fricker, Mikko Gynther, Ulrika H Julku, Henri J Huttunen, Stephen J Haggarty, Timo T Myöhänen.
      Tauopathies are neurodegenerative diseases that are characterized by accumulation of hyperphosphorylated tau protein, higher-order aggregates, and tau filaments. Protein phosphatase 2A (PP2A) is a major tau dephosphorylating phosphatase, and a decrease in its activity has been demonstrated in tauopathies, including Alzheimer's disease. Prolyl oligopeptidase is a serine protease that is associated with neurodegeneration, and its inhibition normalizes PP2A activity without toxicity under pathological conditions. Here, we assessed whether prolyl oligopeptidase inhibition could protect against tau-mediated toxicity in cellular models in vitro and in the PS19 transgenic mouse model of tauopathy carrying the human tau-P301S mutation. We show that inhibition of prolyl oligopeptidase with the inhibitor KYP-2047 reduced tau aggregation in tau-transfected HEK-293 cells and N2A cells as well as in human iPSC-derived neurons carrying either the P301L or tau-A152T mutation. Treatment with KYP-2047 resulted in increased PP2A activity and activation of autophagic flux in HEK-293 cells and N2A cells and in patient-derived iNeurons, as indicated by changes in autophagosome and autophagy receptor markers; this contributed to clearance of insoluble tau. Furthermore, treatment of PS19 transgenic mice for 1 month with KYP-2047 reduced tau burden in the brain and cerebrospinal fluid and slowed cognitive decline according to several behavioral tests. In addition, a reduction in an oxidative stress marker was seen in mouse brains after KYP-2047 treatment. This study suggests that inhibition of prolyl oligopeptidase could help to ameliorate tau-dependent neurodegeneration.
    DOI:  https://doi.org/10.1126/scitranslmed.abq2915
  51. Nat Microbiol. 2023 Apr 10.
    Autophagy restricts Mycobacterium tuberculosis during acute infection in mice.
    Guillaume R Golovkine, Allison W Roberts, Huntly M Morrison, Rafael Rivera-Lugo, Rita M McCall, Hannah Nilsson, Nicholas E Garelis, Teresa Repasy, Michael Cronce, Jonathan Budzik, Erik Van Dis, Lauren M Popov, Gabriel Mitchell, Reena Zalpuri, Danielle Jorgens, Jeffery S Cox.
      Whether or not autophagy has a role in defence against Mycobacterium tuberculosis infection remains unresolved. Previously, conditional knockdown of the core autophagy component ATG5 in myeloid cells was reported to confer extreme susceptibility to M. tuberculosis in mice, whereas depletion of other autophagy factors had no effect on infection. We show that doubling cre gene dosage to more robustly deplete ATG16L1 or ATG7 resulted in increased M. tuberculosis growth and host susceptibility in mice, although ATG5-depleted mice are more sensitive than ATG16L1- or ATG7-depleted mice. We imaged individual macrophages infected with M. tuberculosis and identified a shift from apoptosis to rapid necrosis in autophagy-depleted cells. This effect was dependent on phagosome permeabilization by M. tuberculosis. We monitored infected cells by electron microscopy, showing that autophagy protects the host macrophage by partially reducing mycobacterial access to the cytosol. We conclude that autophagy has an important role in defence against M. tuberculosis in mammals.
    DOI:  https://doi.org/10.1038/s41564-023-01354-6
  52. Prog Neuropsychopharmacol Biol Psychiatry. 2023 Apr 12. pii: S0278-5846(23)00050-7. [Epub ahead of print] 110764
    Heterozygous Cc2d1a mice show sex-dependent changes in the Beclin-1/p62 ratio with impaired prefrontal cortex and hippocampal autophagy.
    Elif Funda Sener, Halime Dana, Reyhan Tahtasakal, Zuhal Hamurcu, Serpil Taheri, Nesrin Delibasi, Ecmel Mehmetbeyoglu, Zeynep Yilmaz Sukranli, Fatma Dal, Esra Tufan, Asli Okan Oflamaz, Zuleyha Doganyigit, Yusuf Ozkul, Minoo Rassoulzadegan.
      Autism Spectrum Disorders (ASD) are a group of neurodevelopmental disorders characterized by repetitive behaviors, lack of social interaction and communication. CC2D1A is identified in patients as an autism risk gene. Recently, we suggested that heterozygous Cc2d1a mice exhibit impaired autophagy in the hippocampus. We now report the analysis of autophagy markers (Lc3, Beclin and p62) in different regions hippocampus, prefrontal cortex, hypothalamus and cerebellum, with an overall decrease in autophagy and changes in Beclin-1/p62 ratio in the hippocampus. We observed sex-dependent variations in transcripts and protein expression levels. Moreover, our analyses suggest that alterations in autophagy initiated in Cc2d1a heterozygous parents are variably transmitted to offspring, even when the offspring's genotype is wild type. Aberration in the autophagy mechanism may indirectly contribute to induce synapse alteration in the ASD brain.
    Keywords:  Autism; Autophagy; Cc2d1a; Hippocampus; Mouse; Prefrontal cortex; Protein; RNA
    DOI:  https://doi.org/10.1016/j.pnpbp.2023.110764
  53. J Pineal Res. 2023 Apr 11.
    Melatonin protects against developmental PBDE-47 neurotoxicity by targeting the AMPK/mitophagy axis.
    Lixin Dong, Qian Sun, Haixia Qiu, Kaichao Yang, Xiao Boya, Tao Xia, Aiguo Wang, Hui Gao, Shun Zhang.
      The neurotoxicity of 2,2',4,4'-tetrabromodiphenyl ether (PBDE-47) is closely linked to mitochondrial abnormalities while mitophagy is vital for mitochondrial homeostasis. However, whether PBDE-47 disrupts mitophagy contributing to impaired neurodevelopment remain elusive. Here, this study showed that neonatal PBDE-47 exposure caused learning and memory deficits in adult rats, accompanied with striatal mitochondrial abnormalities, neuronal apoptosis and the resultant neuronal loss. Mechanistically, PBDE-47 suppressed PINK1/Parkin-mediated mitophagy induction and degradation, inducing mitophagosome accumulation and mitochondrial dysfunction in vivo and in vitro. Additionally, stimulation of mitophagy by adenovirus-mediated Parkin or Autophagy-related protein 7 (Atg7) overexpression aggravated PBDE-47-induced mitophagosome accumulation, mitochondrial dysfunction, neuronal apoptosis and death. Conversely, suppression of mitophagy by the siRNA knockdown of Atg7 rescued PBDE-47-induced detrimental consequences. Importantly, melatonin, a hormone secreted rhythmically by the pineal, improved PBDE-47-caused neurotoxicity via preventing neuronal apoptosis and loss by restoring mitophagic activity and mitochondrial function. These neuroprotective effects of melatonin depended on activation of the AMP-activated protein kinase (AMPK)/unc-51 like autophagy activating kinase 1 (ULK1) signaling. Collectively, these data indicate that PBDE-47 impairs mitophagy to perturb mitochondrial homeostasis, thus triggering apoptosis, leading to neuronal loss and consequent neurobehavioral deficits. Manipulation of the AMPK-mitophagy axis via melatonin could be a novel therapeutic strategy against developmental PBDE-47 neurotoxicity. This article is protected by copyright. All rights reserved.
    Keywords:  2,2’,4,4’-tetrabromodiphenyl ether; AMPK/ULK1; Melatonin; Mitophagy; PINK1/Parkin
    DOI:  https://doi.org/10.1111/jpi.12871
  54. Nutrients. 2023 Apr 05. pii: 1774. [Epub ahead of print]15(7):
    Hydroxytyrosol Interference with Inflammaging via Modulation of Inflammation and Autophagy.
    Francesca Velotti, Roberta Bernini.
      Inflammaging refers to a chronic, systemic, low-grade inflammation, driven by immune (mainly macrophages) and non-immune cells stimulated by endogenous/self, misplaced or altered molecules, belonging to physiological aging. This age-related inflammatory status is characterized by increased inflammation and decreased macroautophagy/autophagy (a degradation process that removes unnecessary or dysfunctional cell components). Inflammaging predisposes to age-related diseases, including obesity, type-2 diabetes, cancer, cardiovascular and neurodegenerative disorders, as well as vulnerability to infectious diseases and vaccine failure, representing thus a major target for anti-aging strategies. Phenolic compounds-found in extra-virgin olive oil (EVOO)-are well known for their beneficial effect on longevity. Among them, hydroxytyrosol (HTyr) appears to greatly contribute to healthy aging by its documented potent antioxidant activity. In addition, HTyr can modulate inflammation and autophagy, thus possibly counteracting and reducing inflammaging. In this review, we reference the literature on pure HTyr as a modulatory agent of inflammation and autophagy, in order to highlight its possible interference with inflammaging. This HTyr-mediated activity might contribute to healthy aging and delay the development or progression of diseases related to aging.
    Keywords:  age-related diseases; aging; autophagy; cytokines; extra-virgin olive oil; hydroxytyrosol; inflammaging; inflammation; olive vegetation waste; polyphenols
    DOI:  https://doi.org/10.3390/nu15071774
  55. Molecules. 2023 Mar 29. pii: 3041. [Epub ahead of print]28(7):
    Effect of N-acetyl-l-cysteine on Cell Phenotype and Autophagy in Pichia pastoris Expressing Human Serum Albumin and Porcine Follicle-Stimulating Hormone Fusion Protein.
    Yingqing Xu, Zijian Geng, Chengxi Yang, Hongwei Zhou, Yixing Wang, Buayisham Kuerban, Gang Luo.
      Pichia pastoris is widely used for the production of recombinant proteins, but the low secretion efficiency hinders its wide application in biopharmaceuticals. Our previous study had shown that N-acetyl-l-cysteine (NAC) promotes human serum albumin and porcine follicle-stimulating hormone fusion protein (HSA-pFSHβ) secretion by increasing intracellular GSH levels, but the downstream impact mechanism is not clear. In this study, we investigated the roles of autophagy as well as cell phenotype in NAC promoting HSA-pFSHβ secretion. Our results showed that NAC slowed down the cell growth rate, and its effects were unaffected by Congo Red and Calcofluor White. Moreover, NAC affected cell wall composition by increasing chitin content and decreasing β-1,3-glucan content. In addition, the expressions of vesicular pathway and autophagy-related genes were significantly decreased after NAC treatment. Further studies revealed that autophagy, especially the cytoplasm-to-vacuole targeting (Cvt) pathway, mitophagy and pexophagy, was significantly increased with time, and NAC has a promoting effect on autophagy, especially at 48 h and 72 h of NAC treatment. However, the disruption of mitophagy receptor Atg32, but not pexophagy receptor Atg30, inhibited HSA-pFSHβ production, and neither of them inhibited the NAC-promoted effect of HSA-pFSHβ. In conclusion, vesicular transport, autophagy and cell wall are all involved in the NAC-promoted HSA-pFSHβ secretion and that disruption of the autophagy receptor alone does not inhibit the effect of NAC.
    Keywords:  N-acetyl-l-cysteine; Pichia pastoris; autophagy; cell wall
    DOI:  https://doi.org/10.3390/molecules28073041
  56. Mol Med. 2023 04 10. 29(1): 51
    Glycyrrhizin, an inhibitor of HMGB1 induces autolysosomal degradation function and inhibits Helicobacter pylori infection.
    Uzma Khan, Bipul Chandra Karmakar, Priyanka Basak, Sangita Paul, Animesh Gope, Deotima Sarkar, Asish Kumar Mukhopadhyay, Shanta Dutta, Sushmita Bhattacharya.
      BACKGROUND: Helicobacter pylori is a key agent for causing gastric complications linked with gastric disorders. In response to infection, host cells stimulate autophagy to maintain cellular homeostasis. However, H. pylori have evolved the ability to usurp the host's autophagic machinery. High mobility group box1 (HMGB1), an alarmin molecule is a regulator of autophagy and its expression is augmented during infection and gastric cancer. Therefore, this study aims to explore the role of glycyrrhizin (a known inhibitor of HMGB1) in autophagy during H. pylori infection.MAIN METHODS: Human gastric cancer (AGS) cells were infected with the H. pylori SS1 strain and further treatment was done with glycyrrhizin. Western blot was used to examine the expression of autophagy proteins. Autophagy and lysosomal activity were monitored by fluorescence assays. A knockdown of HMGB1 was performed to verify the effect of glycyrrhizin. H. pylori infection in in vivo mice model was established and the effect of glycyrrhizin treatment was studied.
    RESULTS: The autophagy-lysosomal pathway was impaired due to an increase in lysosomal membrane permeabilization during H. pylori infection in AGS cells. Subsequently, glycyrrhizin treatment restored the lysosomal membrane integrity. The recovered lysosomal function enhanced autolysosome formation and concomitantly attenuated the intracellular H. pylori growth by eliminating the pathogenic niche. Additionally, glycyrrhizin treatment inhibited inflammation and improved gastric tissue damage in mice.
    CONCLUSION: This study showed that inhibiting HMGB1 restored lysosomal activity to ameliorate H. pylori infection. It also demonstrated the potential of glycyrrhizin as an antibacterial agent to address the problem of antimicrobial resistance.
    Keywords:  Autophagy; Glycyrrhizin; HMGB1; Helicobacter pylori; LMP
    DOI:  https://doi.org/10.1186/s10020-023-00641-6
  57. Int J Mol Sci. 2023 Mar 28. pii: 6338. [Epub ahead of print]24(7):
    Genetic Evidence for Endolysosomal Dysfunction in Parkinson's Disease: A Critical Overview.
    Vidal Yahya, Alessio Di Fonzo, Edoardo Monfrini.
      Parkinson's disease (PD) is the second most common neurodegenerative disorder in the aging population, and no disease-modifying therapy has been approved to date. The pathogenesis of PD has been related to many dysfunctional cellular mechanisms, however, most of its monogenic forms are caused by pathogenic variants in genes involved in endolysosomal function (LRRK2, VPS35, VPS13C, and ATP13A2) and synaptic vesicle trafficking (SNCA, RAB39B, SYNJ1, and DNAJC6). Moreover, an extensive search for PD risk variants revealed strong risk variants in several lysosomal genes (e.g., GBA1, SMPD1, TMEM175, and SCARB2) highlighting the key role of lysosomal dysfunction in PD pathogenesis. Furthermore, large genetic studies revealed that PD status is associated with the overall "lysosomal genetic burden", namely the cumulative effect of strong and weak risk variants affecting lysosomal genes. In this context, understanding the complex mechanisms of impaired vesicular trafficking and dysfunctional endolysosomes in dopaminergic neurons of PD patients is a fundamental step to identifying precise therapeutic targets and developing effective drugs to modify the neurodegenerative process in PD.
    Keywords:  Parkinson’s disease; endolysosomes; genetics; lysosomes; synaptic vesicles
    DOI:  https://doi.org/10.3390/ijms24076338
  58. Cell Biochem Funct. 2023 Apr 10.
    SGLT2 inhibitors and autophagy in diabetes.
    Habib Yaribeygi, Mina Maleki, Stephen L Atkin, Tannaz Jamialahmadi, Amirhossein Sahebkar.
      Autophagy is a physiological event in mammalian cells to promote cell survival and efficiency in tissues, but it may turn to be a pathological process in disease conditions such as in diabetes. Chronic hyperglycemia induces aberrant autophagy and promotes cellular death as a main underlying cause of diabetes-related complications. Therefore, autophagy-modifying therapy may be of value to prevent the development of complications. Sodium-glucose cotransporter 2 inhibitors (SGLT2is) are a class of newly introduced antidiabetic drugs that achieve normoglycemia through causing overt glycosuria. There is evidence that these drugs may have pleiotropic extra-glycemic benefits, but their effect on the autophagy process is unclear; therefore, this review was undertaken to clarify the possible effects of SGLT2is on autophagy.
    Keywords:  SGLT2i; autophagy; diabetes mellitus; sodium-glucose cotransporter 2 inhibitors; sodium-hydrogen exchangers
    DOI:  https://doi.org/10.1002/cbf.3792
  59. Int J Biol Sci. 2023 ;19(5): 1509-1527
    LTF Induces Radioresistance by Promoting Autophagy and Forms an AMPK/SP2/NEAT1/miR-214-5p Feedback Loop in Lung Squamous Cell Carcinoma.
    Junmiao Wen, Wang Zheng, Liang Zeng, Boyan Wang, Donglai Chen, Yongbing Chen, Xueguan Lu, Chunlin Shao, Jiayan Chen, Min Fan.
      Radiotherapy is the most predominant treatment strategy for lung squamous cell carcinoma (LUSC) patients, but radioresistance is the major obstacle to therapy effectiveness. The mechanisms and regulators of LUSC radioresistance remain unclear. Here, lactotransferrin (LTF) is found to be significantly upregulated in radioresistant LUSC cell lines (H226R and H1703R) and clinical samples and promotes radioresistance of LUSC both in vitro and in vivo. Comprehensive enrichment analyses suggested that LTF potentially modulates autophagy in LUSC. Interestingly, the level of autophagy was raised in the radioresistant cells, and suppression of autophagy sensitized LUSC to irradiation. Functional experiments showed that LTF deficiency inhibits cellular autophagy through the AMPK pathway, ultimately leading to radiosensitization. Mechanistically, LTF can directly interact with AMPK to facilitate its phosphorylation and activate autophagy signaling. Moreover, NEAT1 functions as a ceRNA that targets miR-214-5p resulting in an increased LTF expression. Intriguingly, SP2, a transcription factor regulated by AMPK, induced NEAT1 expression by directly binding to its promoter region and thus forming a LTF/AMPK/SP2/NEAT1/miR-214-5p feedback loop. Our work reveals for the first time that LTF induces radioresistance by promoting autophagy and enhancing its self-expression via forming a positive feedback loop, suggesting that LTF is an appealing radiosensitization target for treating LUSC.
    Keywords:  LTF; autophagy; lung cancer; radioresistance
    DOI:  https://doi.org/10.7150/ijbs.78669
  60. Bio Protoc. 2023 Apr 05. 13(7): e4651
    Fluorescence Assays for Real-Time Tracking of Cell Surface Protein Internalization and Endosomal Sorting in Axons of Primary Mouse Hippocampal Neurons.
    Tai Chaiamarit, Yin Wu, Adriaan Verhelle, Sandra E Encalada.
      The trafficking and sorting of proteins through the secretory-endolysosomal system is critical for the proper functioning of neurons. Defects in steps of these pathways are associated with neuronal toxicity in various neurodegenerative disorders. The prion protein (PrP) is a glycosylphosphatidylinositol (GPI)-anchored protein that follows the secretory pathway before reaching the cell surface. Following endocytosis from the cell surface, PrP sorts into endosomes and lysosomes for further recycling and degradation, respectively. A few detailed protocols using drug treatments and fluorescent dyes have previously allowed the tracking of PrP trafficking routes in real time in non-neuronal cells. Here, we present a protocol optimized for primary neurons that aims to monitor and/or manipulate the trafficking and sorting of PrP particles at several steps during their secretory-endolysosomal itineraries, including (a) ER export, (b) endocytosis, (c) lysosomal degradation, and (d) accumulation in axonal endolysosomes. These primary neuron live assays allow for the robust quantitation of accumulation and/or degradation of PrP or of other membrane-associated proteins that transition from the ER to the Golgi via the cell surface. Graphical abstract.
    Keywords:  ARESTA; Axonal transport; Endocytosis; Endoggresomes; Endosomes; PrP; Primary neurons; Trafficking
    DOI:  https://doi.org/10.21769/BioProtoc.4651
  61. Obes Rev. 2023 Apr 13. e13567
    Maternal obesity and offspring health: Adapting metabolic changes through autophagy and mitophagy.
    Litao Wang, Aislinn M O'Kane, Yingmei Zhang, Jun Ren.
      Maternal obesity leads to obstetric complications and a high prevalence of metabolic anomalies in the offspring. Among various contributing factors for maternal obesity-evoked health sequelae, developmental programming is considered as one of the leading culprit factors for maternal obesity-associated chronic comorbidities. Although a unified theory is still lacking to systematically address multiple unfavorable postnatal health sequelae, a cadre of etiological machineries have been put forward, including lipotoxicity, inflammation, oxidative stress, autophagy/mitophagy defect, and cell death. Hereinto, autophagy and mitophagy play an essential housekeeping role in the clearance of long-lived, damaged, and unnecessary cell components to maintain and restore cellular homeostasis. Defective autophagy/mitophagy has been reported in maternal obesity and negatively impacts fetal development and postnatal health. This review will provide an update on metabolic disorders in fetal development and postnatal health issues evoked by maternal obesity and/or intrauterine overnutrition and discuss the possible contribution of autophagy/mitophagy in metabolic diseases. Moreover, relevant mechanisms and potential therapeutic strategies will be discussed in an effort to target autophagy/mitophagy and metabolic disturbances in maternal obesity.
    Keywords:  autophagy; maternal obesity; mitophagy; offspring health
    DOI:  https://doi.org/10.1111/obr.13567
  62. Int J Mol Sci. 2023 Mar 27. pii: 6309. [Epub ahead of print]24(7):
    Hyperglycemia Aggravates Periodontitis via Autophagy Impairment and ROS-Inflammasome-Mediated Macrophage Pyroptosis.
    Zhenxing Zhao, Ye Ming, Xiang Li, Hao Tan, Xinyi He, Lan Yang, Jinlin Song, Leilei Zheng.
      Macrophage pyroptosis drives the secretion of IL-1β, which has been recently reported to be a featured salivary biomarker for discriminating periodontitis in the presence of diabetes. This study aimed to explore whether macrophage pyroptosis plays a role in the development of diabetes mellitus-periodontitis, as well as potential therapeutic strategies. By establishing a model of experimental diabetes mellitus-periodontitis in rats, we found that IL-1β and gasdermin D were highly expressed, leading to aggravated destruction of periodontal tissue. MCC950, a potent and selective molecule inhibitor of the NLRP3 inflammasome, effectively inhibited macrophage pyroptosis and attenuated alveolar bone losses in diabetes mellitus-periodontitis. Consistently, in vitro, high glucose could induce macrophage pyroptosis and thus promoted IL-1β production in macrophages stimulated by lipopolysaccharide. In addition, autophagy blockade by high glucose via the mTOR-ULK1 pathway led to severe oxidative stress response in macrophages stimulated by lipopolysaccharide. Activation of autophagy by rapamycin, clearance of mitochondrial ROS by mitoTEMPO, and inhibition of inflammasome by MCC950 could significantly reduce macrophage pyroptosis and IL-1β secretion. Our study demonstrates that hyperglycemia promotes IL-1β production and pyroptosis in macrophages suffered by periodontal microbial stimuli. Modulation of autophagy activity and specific targeting of the ROS-inflammasome pathway may offer promising therapeutic strategies to alleviate diabetes mellitus-periodontitis.
    Keywords:  MCC950; autophagy; hyperglycemia; oxidative stress; periodontal disease; pyroptosis
    DOI:  https://doi.org/10.3390/ijms24076309
  63. Int J Mol Sci. 2023 Apr 03. pii: 6662. [Epub ahead of print]24(7):
    Pharmacological Targeting of Bcl-2 Induces Caspase 3-Mediated Cleavage of HDAC6 and Regulates the Autophagy Process in Colorectal Cancer.
    Donglin Yang, Liujun He, Shuiqing Ma, Shiqiang Li, Yajun Zhang, Chunsheng Hu, Jiuhong Huang, Zhigang Xu, Dianyong Tang, Zhongzhu Chen.
      Compound 6d, a spiroindoline compound, exhibits antiproliferative capability against cancer cell lines. However, the exact underlying mechanism of this compound-mediated inhibitory capability remains unclear. Here, we showed that compound 6d is an inhibitor of Bcl-2, which suppresses CRC growth by inducing caspase 3-mediated intrinsic apoptosis of mitochondria. Regarding the underlying mechanism, we identified HDAC6 as a direct substrate for caspase 3, and caspase 3 activation induced by compound 6d directly cleaves HDAC6 into two fragments. Moreover, the cleavage site was located at D1088 in the DMAD-S motif HDAC6. Apoptosis stimulated by compound 6d promoted autophagy initiation by inhibiting interaction between Bcl-2 and Beclin 1, while it led to the accumulation of ubiquitinated proteins and the reduction of autophagic flux. Collectively, our findings reveal that the Bcl-2-caspase 3-HDAC6 cascade is a crucial regulatory pathway of autophagy and identify compound 6d as a novel lead compound for disrupting the balance between apoptosis and autophagy.
    Keywords:  Bcl-2; HDAC6; autophagy; caspase 3; colorectal cancer cells; compound 6d
    DOI:  https://doi.org/10.3390/ijms24076662
  64. JACC Basic Transl Sci. 2023 Mar;8(3): 340-355
    Apolipoprotein M Attenuates Anthracycline Cardiotoxicity and Lysosomal Injury.
    Zhen Guo, Carla Valenzuela Ripoll, Antonino Picataggi, David R Rawnsley, Mualla Ozcan, Julio A Chirinos, Ezhilarasi Chendamarai, Amanda Girardi, Terrence Riehl, Hosannah Evie, Ahmed Diab, Attila Kovacs, Krzysztof Hyrc, Xiucui Ma, Aarti Asnani, Swapnil V Shewale, Marielle Scherrer-Crosbie, Lauren Ashley Cowart, John S Parks, Lei Zhao, David Gordon, Francisco Ramirez-Valle, Kenneth B Margulies, Thomas P Cappola, Ankit A Desai, Lauren N Pedersen, Carmen Bergom, Nathan O Stitziel, Michael P Rettig, John F DiPersio, Stefan Hajny, Christina Christoffersen, Abhinav Diwan, Ali Javaheri.
      Apolipoprotein M (ApoM) binds sphingosine-1-phosphate (S1P) and is inversely associated with mortality in human heart failure (HF). Here, we show that anthracyclines such as doxorubicin (Dox) reduce circulating ApoM in mice and humans, that ApoM is inversely associated with mortality in patients with anthracycline-induced heart failure, and ApoM heterozygosity in mice increases Dox-induced mortality. In the setting of Dox stress, our studies suggest ApoM can help sustain myocardial autophagic flux in a post-transcriptional manner, attenuate Dox cardiotoxicity, and prevent lysosomal injury.
    Keywords:  TFEB; anthracycline; apolipoprotein M; autophagy; cardiomyopathy
    DOI:  https://doi.org/10.1016/j.jacbts.2022.09.010
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