bims-auttor 2025-04-27 papers

bims-auttor

Biomed News

on Autophagy and mTOR

Issue of 2025–04–27
thirty-two papers selected by
Viktor Korolchuk, Newcastle University

Alpha-synuclein mutations mislocalize cytoplasmic p300 compromising autophagy, which is rescued by ACLY inhibition.
Autophagosomes anchor an AKAP11-dependent regulatory checkpoint that shapes neuronal PKA signaling.
SMAD3 and PINK1 constitute a new positive feedback loop in regulation of mitophagy.
ATP2A2 regulates STING1/MITA-driven signal transduction including selective autophagy.
Mitochondrial Proteases and Their Roles in Mitophagy in Plants, Animals, and Yeast.
Pathogenetic Involvement of Autophagy and Mitophagy in Primary Progressive Multiple Sclerosis.
Niclosamide extends health span and reduces frailty by ameliorating mTORC1 hyperactivation in aging models.
Trafficking to the lysosome: HOPS paves the way.
Silencing GGH induces autophagy by increasing folate stress and production of NADH.
A RETREG1/FAM134B isoform switch regulates reticulophagy during myogenesis.
Lysosomes and LAMPs as Autophagy Drivers of Drug Resistance in Colorectal Cancer.
ATG9 inhibits rickettsia binding to the Host cell surface by blocking the rOmpB-XRCC6/KU70 interaction.
Neuronal autophagy controls excitability via ryanodine receptor-mediated regulation of calcium-activated potassium channel function.
Hepatitis B Virus Disrupts the Blood-Testis Barrier via the Induction of mTOR-Dependent Autophagy in Sertoli Cells.
P62 inhibits IL-1β release during Salmonella Typhimurium infection of macrophages.
Age-associated reduction in ER-Mitochondrial contacts impairs mitochondrial lipid metabolism and autophagosome formation in the heart.
Lysosomal EGFR acts as a Rheb-GEF independent of its kinase activity to activate mTORC1.
Roles and applications of autophagy in guarding against environmental stress and DNA damage in Saccharomyces cerevisiae.
Defective autophagy in CD4 T cells drives liver fibrosis via type 3 inflammation.
Premature skeletal muscle aging in VPS13A deficiency relates to impaired autophagy.
PPARγ Activates Autophagy by Suppressing the PI3K-AKT1-FOXO3 Signaling Pathway and thus Alleviates Hepatic Ischemia-Reperfusion Injury.
TTK promotes mitophagy by regulating ULK1 phosphorylation and pre-mRNA splicing to inhibit mitochondrial apoptosis in bladder cancer.
Lysosomal TPC2 channels disrupt Ca2+ entry and dopaminergic function in models of LRRK2-Parkinson's disease.
Aberrant aging-associated p62 autophagic cascade in biopsied olfactory neuronal cells from patients with psychosis.
Trehalose induces bladder smooth muscle hypercontractility in mice: involvement of oxidative stress and cellular senescence.
Autophagy inhibition enhances antifibrotic potential of placental mesenchymal stem cells of fetal origin via regulating TGF-β1 mediated protein degradation of HGF.
Urolithin A alleviates radiation pneumonitis by activating PINK1/PRKN-mediated Mitophagy.
Curcumin ameliorates aging-induced blood-testis barrier disruption by regulating AMPK/mTOR mediated autophagy.
Biliverdin alleviates cerebral ischemia-reperfusion injury by regulating the P4hb/MAPK/mTOR pathway to inhibit autophagy.
High throughput screening assay for the identification of ATF4 and TFEB activating compounds.
Loss of intracellular ATP affects axoplasmic viscosity and pathological protein aggregation in mammalian neurons.
Re-epithelialization of cancer cells increases autophagy and DNA damage: Implications for breast cancer dormancy and relapse.

Neuron. 2025 Apr 14. pii: S0896-6273(25)00247-8. [Epub ahead of print]

Alpha-synuclein mutations mislocalize cytoplasmic p300 compromising autophagy, which is rescued by ACLY inhibition.

Sung Min Son, Farah H Siddiqi, Ana Lopez, Rizwan Ansari, Sylwia D Tyrkalska, So Jung Park, Tilo Kunath, Emmanouil Metzakopian, Angeleen Fleming, David C Rubinsztein.

  Triplications and certain point mutations in the SNCA gene, encoding alpha-synuclein (α-Syn), cause Parkinson's disease (PD). Here, we demonstrate that the PD-causing A53T α-Syn mutation and elevated α-Syn expression perturb acetyl-coenzyme A (CoA) and p300 biology in human neurons and in the CNS of zebrafish and mice. This dysregulation is mediated by activation of ATP-citrate lyase (ACLY), a key enzyme that generates acetyl-CoA in the cytoplasm, via two mechanisms. First, ACLY activity increases acetyl-CoA levels, which activate p300. Second, ACLY activation increases LKB1 acetylation, which inhibits AMPK, leading to increased cytoplasmic and decreased nuclear p300. This lowers histone acetylation and increases acetylation of cytoplasmic p300 substrates, like raptor, which causes mechanistic target of rapamycin complex 1 (mTORC1) hyperactivation, thereby impairing autophagy. ACLY inhibitors rescue pathological phenotypes in PD neurons, organoids, zebrafish, and mouse models, suggesting that this pathway is a core feature of α-Syn toxicity and that ACLY may be a suitable therapeutic target.

Keywords:  ACLY; AMPK; Parkinson's disease; acetyl-CoA; acetylation; alpha-synuclein; autophagy; mTORC1; nucleocytoplasmic shuttling of p300

DOI:  https://doi.org/10.1016/j.neuron.2025.03.028
EMBO J. 2025 Apr 22.

Autophagosomes anchor an AKAP11-dependent regulatory checkpoint that shapes neuronal PKA signaling.

Ashley Segura-Roman, Y Rose Citron, Myungsun Shin, Nicole Sindoni, Alex Maya-Romero, Simon Rapp, Claire Goul, Joseph D Mancias, Roberto Zoncu.

  Protein Kinase A (PKA) is regulated spatially and temporally via scaffolding of its catalytic (Cα) and regulatory (RI/RII) subunits by the A-kinase-anchoring proteins (AKAP). By binding to an AKAP11 scaffold, PKA engages in poorly understood interactions with autophagy, a key degradation pathway for neuronal cell homeostasis. Mutations in AKAP11 promote schizophrenia and bipolar disorders (SZ-BP) through unknown mechanisms. Here, through proteomic-based analyses of immunopurified lysosomes, we identify the Cα-RIα-AKAP11 holocomplex as a prominent autophagy-associated protein-kinase complex. AKAP11 scaffolds Cα-RIα interaction with the autophagic machinery via its LC3-interacting region (LIR), enabling both PKA regulation by upstream signals, and its autophagy-dependent degradation. We identify Ser83 on the RIα linker-hinge region as an AKAP11-dependent phospho-residue that modulates RIα-Cα binding to the autophagosome and cAMP-induced PKA activation. Decoupling AKAP11-PKA from autophagy alters downstream phosphorylation events, supporting an autophagy-dependent checkpoint for PKA signaling. Ablating AKAP11 in induced pluripotent stem cell-derived neurons reveals dysregulation of multiple pathways for neuronal homeostasis. Thus, the autophagosome is a platform that modulates PKA signaling, providing a possible mechanistic link to SZ/BP pathophysiology.

Keywords:  AKAP11; Autophagy; Phosphoproteomics; Protein kinase A; Signaling

DOI:  https://doi.org/10.1038/s44318-025-00436-x
Autophagy. 2025 Apr 25. 1-3

SMAD3 and PINK1 constitute a new positive feedback loop in regulation of mitophagy.

Mingzhu Tang, Guang Lu, Han-Ming Shen.

  Mitophagy, selective degradation of dysfunctional mitochondria by the autophagy-lysosome pathway, is critical for maintaining cellular homeostasis. In recent years, significant progress has been made in understanding how PINK1 (PTEN-induced kinase 1)-mediated phosphorylation and the E3 ubiquitin (Ub) ligase (PRKN/parkin)-mediated ubiquitination form a positive feedforward loop in control of mitophagy. Nevertheless, a fundamental question remains: How is PINK1 transcriptionally modulated under mitochondrial stress to finely support mitophagy? Recently, we unveiled a novel mechanism in control of PINK1 transcription by SMAD3 (SMAD family member 3), an essential component of the TGFB/TGFβ (transforming growth factor beta)-SMAD signaling pathway. Upon mitochondrial depolarization, SMAD3 is activated through PINK1-mediated phosphorylation of SMAD3 at serine 423/425 independent of canonical TGFB signaling. More importantly, the SMAD3-PINK1 regulatory axis appears to functionally provide a pro-survival mechanism against mitochondrial stress. Therefore, PINK1 and SMAD3 constitute a newly discovered positive feedforward loop to regulate mitophagy, highlighting the need for further exploring the crosstalk between TGFB-SMAD signaling and mitophagy.

Keywords:  Mitophagy; PINK1; SMAD3; phosphorylation; transcription

DOI:  https://doi.org/10.1080/15548627.2025.2496364
Autophagy. 2025 Apr 23.

ATP2A2 regulates STING1/MITA-driven signal transduction including selective autophagy.

Xue Yang, Linyue Lv, Yuelan Zhang, Zhuyou Zhang, Shaowei Zeng, Xinyi Zhang, Qinyang Wang, Martin Dorf, Shitao Li, Bishi Fu.

  STING1/MITA not only induces innate immune responses but also triggers macroautophagy/autophagy to selectively degrade signaling molecules. However, the molecular mechanisms regulating STING1-mediated selective autophagy remain unclear. Here, we first report that ATP2A2 directly interacts with STING1, regulating STING1-mediated innate immune response by modulating its polymerization and trafficking, thereby inhibiting DNA virus infection. Notably, while screening for reticulophagy receptors involved in STING1-mediated selective autophagy, we identified SEC62 as an important receptor protein in STING1-mediated reticulophagy. Mechanistically, SEC62 strengthens its interaction with STING1 upon activation and concurrently facilitates STING1-mediated reticulophagy upon starvation, which are dependent on ATP2A2. Furthermore, knocking down SEC62 in WT cells inhibits STING1-mediated MAP1LC3B/LC3B lipidation and autophagosome formation, an effect that is lost in ATP2A2 knockout cells, suggesting that SEC62's role in STING1-mediated selective autophagy is ATP2A2 dependent. Thus, our findings identify the reticulophagy receptor SEC62 as a novel receptor protein regulating STING1-mediated selective autophagy, providing new insight into the mechanism regarding a reticulophagy receptor in the process of STING1-induced selective autophagy.

Keywords:  ATP2A2; Antiviral; SEC62; STING1/MITA; innate immunity; selective autophagy

DOI:  https://doi.org/10.1080/15548627.2025.2496786
Plant Cell Physiol. 2025 Apr 23. pii: pcaf038. [Epub ahead of print]

Mitochondrial Proteases and Their Roles in Mitophagy in Plants, Animals, and Yeast.

Kacper Ludwig, Małgorzata Heidorn-Czarna.

  Mitochondria play a central role in cellular respiration and other essential metabolic and signaling pathways. To function properly, mitochondria require the maintenance of proteostasis-a balance between protein synthesis and degradation. This balance is achieved through the mitochondrial protein quality control (mtPQC) system, which includes mitochondrial proteases and mitophagy. Mitochondrial proteases ensure proper protein sorting within the mitochondria and maintain proteome homeostasis by degrading unassembled, damaged, or short-lived regulatory proteins. Numerous studies have demonstrated the critical role of mitochondrial proteases in regulating mitophagy-the selective degradation of damaged, aging, or excess mitochondria or their fragments via autophagy. Notably, the rhomboid PARL protease is involved in ubiquitin-dependent PINK1-Parkin mitophagy in mammals while the i-AAA protease Yme1 plays a role in mitophagy in budding yeast. Despite the conservation of core autophagy genes, knowledge about the molecular mechanisms and protein regulators of mitophagy in plants remains limited. In this review, we discuss recent advances in understanding the roles of mitochondrial proteases and mitophagy across plants, animals, and yeast. By comparing these mechanisms across kingdoms, we highlight the potential regulatory function of the plant i-AAA mitochondrial protease in controlling mitophagy, providing new insights into mitochondrial protein quality control networks in plants.

Keywords:   Arabidopsis thaliana ; i-AAA protease; mitochondria; mitochondrial proteases; mitochondrial protein quality control system; mitophagy

DOI:  https://doi.org/10.1093/pcp/pcaf038
J Cell Mol Med. 2025 Apr;29(8): e70455

Pathogenetic Involvement of Autophagy and Mitophagy in Primary Progressive Multiple Sclerosis.

Simone Patergnani, Michele Laudisi, Massimo Bonora, Giulio Righes, Sofia Straudi, Mariusz R Wieckowski, Ilaria Casetta, Luana Semenzato, Konstantinos Koutsikos, Veronica Zanato, Carlotta Giorgi, Paolo Pinton.

  Primary progressive multiple sclerosis (PPMS) affects a subset of MS patients and is characterised by continuous progression from the onset. The molecular mechanisms underlying PPMS are poorly understood, and therapeutic options are limited, with no specific markers for early detection and monitoring. This study investigated the roles of autophagy and mitophagy in PPMS. We found that autophagy markers (ATG5 and ATG7) and mitophagy markers (Parkin and Optineurin) were significantly reduced in the serum of PPMS patients compared to control and relapsing-remitting MS (RRMS) individuals. This reduction was associated with an increase in markers indicative of neurodegeneration and mitochondrial dysfunction. Additionally, a positive correlation between autophagy and mitophagy proteins in the PPMS group suggests that these mechanisms are reciprocally associated and modulated in PPMS. Our investigation reveals that autophagy and mitophagy are actively involved in PPMS and exhibit distinct patterns across MS subtypes. Measurements of circulating components related to autophagy and mitophagy could serve as potential biomarkers for early PPMS detection.

Keywords:  ATG5; ATG7; GFAP; Optineurin; Parkin; biomarker; lactate; serum

DOI:  https://doi.org/10.1111/jcmm.70455
J Adv Res. 2025 Apr 22. pii: S2090-1232(25)00271-1. [Epub ahead of print]

Niclosamide extends health span and reduces frailty by ameliorating mTORC1 hyperactivation in aging models.

Pyeong Geun Choi, Hee Soo Kim, So-Hyun Park, Hyo-Deok Seo, Jeong-Hoon Hahm, Yang Hoon Huh, Tail-Il Jeon, Jiyun Ahn, Chang Hwa Jung.

   INTRODUCTION: Frailty is characterized by an increased vulnerability to disease and physical debilitation due to a decline in the body's capacity to maintain homeostasis during aging. Therefore, effective management of frailty is crucial for promoting health. Although the role of niclosamide (NIC), an autophagy promoter, has been studied for the treatment of cancer, infectious diseases, and metabolic disorders, no research has focused on its effects on aging.
OBJECTIVES: In this study, we aimed to evaluate the effects of NIC on the aging process and assess its potential as a novel anti-aging therapeutic agent.
METHODS: We evaluated the effects of NIC on frailty, physical function, and metabolic function using Caenorhabditis elegans (C. elegans) and aging mouse models. NIC effectiveness was assessed using behavioral experiments, histological analysis, and molecular biological analysis.
RESULTS: We identified NIC as a compound that enhanced exercise capacity and metabolism, thereby alleviating frailty. Briefly, NIC extended the lifespan and improved frailty-related phenotypes in C. elegans, and effectively ameliorated frailty in aging mice, particularly in muscle aging. Additionally, NIC treatment suppressed the muscle atrophy-related ubiquitin-proteasome system induced by mammalian target of rapamycin complex 1 (mTORC1) hyperactivation, while enhancing autophagic flux, another aspect of proteostasis. Furthermore, mRNA-seq analysis revealed that NIC improved metabolism-related functions.
CONCLUSION: Collectively, these findings suggest that NIC is a promising novel candidate for the prevention of frailty.

Keywords:  Aging; Caenorhabditis elegans; Health span; Longevity; Sarcopenia; Skeletal muscle

DOI:  https://doi.org/10.1016/j.jare.2025.04.027
Curr Opin Cell Biol. 2025 Apr 21. pii: S0955-0674(25)00053-5. [Epub ahead of print]94 102515

Trafficking to the lysosome: HOPS paves the way.

Jan van der Beek, Judith Klumperman.

The endo-lysosomal system plays a crucial role in cellular homeostasis by continuously turning over organelles, proteins, and other cargo of intra- or extracellular origin. Moreover, it senses the nutrient status within the cell and can ignite cellular responses by activating or repressing signaling pathways. To enable these roles, lysosomes are fueled by the biosynthetic pathway and receive cargo for degradation by endocytosis and autophagy. Tight regulation and coordination of these distinct trafficking pathways to lysosomes are critical for cellular health. In this review, we explore how these pathways converge at the late stages of the endo-lysosomal system and highlight the role of the HOPS complex as a unifying gatekeeper for trafficking to the lysosome.

DOI: https://doi.org/10.1016/j.ceb.2025.102515
J Mol Cell Biol. 2025 Apr 23. pii: mjaf014. [Epub ahead of print]

Silencing GGH induces autophagy by increasing folate stress and production of NADH.

Yu Li, Yuhui Du, Sijie Chen, Zhangrong Xie, Xinrui Li, Baoyue Lin, Zhiqing Zhou, Huijie Zhao, Guoan Chen.

  There is an inextricable link between metabolic disorders and autophagy. Gamma-glutamyl hydrolase (GGH) is a lysosomal glycoprotein that reduces intracellular folate stress by catalyzing the hydrolysis of polyglutamylated folate into transportable monoglutamate. The relationship between folate metabolism, involving the folate metabolic enzyme GGH, and autophagy has rarely been reported. In this study, we found that GGH functions as a crucial oncogene in lung adenocarcinomas. Importantly, we found that cell autophagy and autophagic cell death are induced by GGH silencing through the elevated folate stress resulting from folate metabolism and the folate metabolite nicotinamide adenine dinucleotide (NADH). By increasing the NADH/NAD + ratio, silencing GGH activates AMPK through the activation of LKB1 and CAMKK2, as well as enhanced AMP/ATP and ADP/ATP ratios, which then triggers the initiation of early autophagy, finally resulting in autophagic cell death. Taken together, our study suggests that GGH may not only serve as a prognostic marker but also play a critical role in the initiation of early autophagy. Interventions targeting GGH to regulate folate metabolism and the proportion of NADH/NAD + may have translational potential for precision therapy in human cancer.

Keywords:  AMPK; FPGS; GGH; autophagy; lung cancer

DOI:  https://doi.org/10.1093/jmcb/mjaf014
Autophagy. 2025 Apr 25. 1-3

A RETREG1/FAM134B isoform switch regulates reticulophagy during myogenesis.

Viviana Buonomo, Michele Cillo, Paolo Grumati.

  During skeletal muscle development, the sarcoplasmic reticulum forms through the homotypic fusion of ER membranes from individual myoblasts. This involves significant ER remodeling, characterized by an overhaul of its proteomic landscape and the activation of reticulophagy. We described how RETREG1/FAM134B is implicated in both shaping ER morphology and degrading ER membranes through reticulophagy. Following myoblast differentiation, the classic RETREG1/FAM134B1 undergoes lysosomal degradation and is progressively replaced by the shorter RETREG1/FAM134B2 isoform. RETREG1/FAM134B2 is a truncated variant of RETREG1/FAM134B1 maintaining an identical C-terminal region, including the functional LIR, but with a partial loss of its reticulon homology domain. The switch between these two isoforms plays a crucial role in ER morphology and muscle development. Re-expressing Retreg1/Fam134b2 in retreg1/fam134b-knockout myoblasts is both necessary and sufficient to rescue the abnormal proteomic landscape and prevent ER dilation. Conversely, the re-expression of Retreg1/Fam134b1 only partially rescues ER defects. We highlighted the role of RETREG1/FAM134B isoforms and reticulophagy in maintaining proper ER dynamics during myogenesis.

Keywords:  Autophagy; FAM134B; RETREG1; myogenesis; reticulophagy

DOI:  https://doi.org/10.1080/15548627.2025.2494803
Cells. 2025 Apr 11. pii: 574. [Epub ahead of print]14(8):

Lysosomes and LAMPs as Autophagy Drivers of Drug Resistance in Colorectal Cancer.

Tsvetomira Ivanova, Yordan Sbirkov, Maria Kazakova, Victoria Sarafian.

  Colorectal cancer (CRC) is among the most malignant pathologies worldwide. A major factor contributing to the poor prognosis of neoplastic diseases is the development of drug resistance. It significantly reduces the utility of most therapeutic protocols and necessitates the search for novel biomarkers and treatment strategies to combat cancer. An evolutionarily conserved catabolic mechanism, autophagy maintains nutrient recycling and metabolic adaptation and is also closely related to carcinogenesis, playing a dual role. Autophagy inhibition can limit the growth of tumors and improve the response to cancer therapeutics. Lysosomes, key players in autophagy, are also considered promising targets for anticancer treatment. There are still insufficient data on the role of poorly studied glycoproteins related to autophagy, such as the lysosome-associated membrane glycoproteins (LAMPs). They can act as multifunctional molecules involved in a multitude of processes like autophagy and cancer development. In the current review, we summarize the recent data on the double-faceted role of autophagy in cancer with a focus on drug resistance in CRC and on the roles of lysosomes and LAMPs in these interconnected processes. Several lysosomotropic drugs are discussed as options to overcome cancer cell chemoresistance. The complex networks that underline defined autophagic pathways in the context of CRC carcinogenesis and the role of autophagy, especially of LAMPs as drivers of drug resistance, are outlined.

Keywords:  CRC; LAMPs; autophagy; drug resistance; lysosomes

DOI:  https://doi.org/10.3390/cells14080574
Autophagy. 2025 Apr 21.

ATG9 inhibits rickettsia binding to the Host cell surface by blocking the rOmpB-XRCC6/KU70 interaction.

Chen Chen, Guoxu Liu, Kehan Xu, Aibao Chen, Ziyang Cheng, Xueping Yan, Ting Zhang, Yan Sun, Tian Yu, Jiayao Wang, Shuangshuang Luo, Weiting Zhou, Shengqun Deng, Yan Liu, Yanan Yang.

  Rickettsiae are tick-borne pathogens that infect human hosts through poorly characterized mechanisms. Herein, we report that ATG9 (autophagy related 9) plays a previously unrecognized role in inhibiting Rickettsia binding to the host cell surface. Unexpectedly, this new function of ATG9 is likely independent of macroautophagy/autophagy. Instead, ATG9 acts as a host defending factor by binding to XRCC6/KU70, a receptor of the Rickettsia outer-membrane protein rOmpB. Both ATG9 and rOmpB bind to the DNA-binding domain of XRCC6, suggesting a competitive role for ATG9 occupying the binding site of rOmpB to abrogate Rickettsia binding. Furthermore, we show that rapamycin transcriptionally activates ATG9 and inhibits rOmpB-mediated infection in a mouse model. Collectively, our study reveals a novel innate mechanism regulating Rickettsia infection and suggests that agonists of ATG9 May be useful for developing therapeutic strategies for the intervention of rickettsial diseases.

Keywords:  Autophagy-related gene; Rickettsia; host defense; infectious disease; rOmpB; tick-borne pathogen

DOI:  https://doi.org/10.1080/15548627.2025.2496363
Proc Natl Acad Sci U S A. 2025 Apr 29. 122(17): e2413651122

Neuronal autophagy controls excitability via ryanodine receptor-mediated regulation of calcium-activated potassium channel function.

Gaga Kochlamazashvili, Aarti Swaminathan, Alexander Stumpf, Amit Kumar, York Posor, Dietmar Schmitz, Volker Haucke, Marijn Kuijpers.

  Glutamate-mediated neuronal hyperexcitation plays a causative role in eliciting seizures and promoting epileptogenesis. Recent data suggest that altered autophagy can contribute to the occurrence of epilepsy. We examined the role of autophagy in neuronal physiology by generating knockout mice conditionally lacking the essential autophagy protein ATG5 in glutamatergic neurons. We demonstrate that conditional genetic blockade of neuronal autophagy results in action potential narrowing, axonal hyperexcitability, and an increase in kainate-induced epileptiform bursts ex vivo, indicative of a lower threshold for the induction of epileptic seizures. Neuronal hyperexcitability in hippocampal slices from conditional ATG5 knockout mice is due to elevated activity of the large conductance calcium-activated potassium channel BKCa downstream of calcium influx via the endoplasmic reticulum (ER)-localized calcium channel ryanodine receptor (RYR). Consistently, pharmacological blockade of RYR or BKCa function rescued hyperexcitability and reduced the frequency of kainate-induced epileptiform bursts in ATG5 cKO brain slices. Our findings reveal a physiological role for neuronal autophagy in the regulation of neuronal excitability via the control of RYR-mediated calcium release, and thereby, calcium-activated potassium channel function in the mammalian brain.

Keywords:  action potential; autophagy; neuronal excitability; potassium channel; ryanodine receptor

DOI:  https://doi.org/10.1073/pnas.2413651122
FASEB J. 2025 Apr 30. 39(8): e70547

Hepatitis B Virus Disrupts the Blood-Testis Barrier via the Induction of mTOR-Dependent Autophagy in Sertoli Cells.

Jingyao Lian, Na Feng, Minyu Xie, Hanbin Zhang, Lei Li, Mohamed Morsi M Ahmed, Zhenguo Chen, Yue Ding, Xiangjin Kang.

  Hepatitis B virus (HBV) is one of the most serious public health threats worldwide. HBV is not only able to pass through the blood-testis barrier (BTB); It can also cause impairment of male fertility. However, the mechanisms involved in this process remain unknown. In this study, we showed that HBV can establish persistent infection in human and mouse testes. Persistent HBV infection triggers inflammatory cell invasion, testes immune homeostasis imbalance, and the disruption of the BTB formed by inter-Sertoli cells. HBV mainly persisted in the Sertoli cells and could induce the autophagy of Sertoli cells by HBV X protein (HBx), a major regulatory protein of HBV. Data indicated that the mTOR signal pathway-mediated autophagy plays a pivotal role in HBV-induced BTB damage. Autophagy inhibitor 3-MA and mTOR activator MHY1485 could ameliorate HBV-induced autophagy and BTB damage. These findings demonstrated that the mTOR-mediated excessive autophagy of Sertoli cells induced by HBx could be one of the pathological mechanisms responsible for the fertility decline caused by HBV infection.

Keywords:  HBV X protein; Sertoli cells; autophagy; immune homeostasis; mTOR pathway

DOI:  https://doi.org/10.1096/fj.202403422R
Front Cell Infect Microbiol. 2025 ;15 1495567

P62 inhibits IL-1β release during Salmonella Typhimurium infection of macrophages.

Nina Judith Hos, Julia Fischer, Ambika M V Murthy, Zahra Hejazi, Martin Krönke, Deniz Hos, Nirmal Robinson.

  Macrophages are critical for the innate immune defense against the facultative intracellular Gram-negative bacterium Salmo\nella enterica serovar Typhimurium. Following phagocytosis by macrophages, S. Typhimurium activates cytoplasmic NLRC3 and NLRP4 inflammasomes, which share the adaptor ASC, resulting in the secretion of the pro-inflammatory cytokine IL-1β. To prevent excessive inflammation and tissue damage, inflammatory signaling pathways are tightly controlled. Recently, autophagy has been suggested to limit inflammation by targeting activated inflammasomes for autophagic degradation. However, the importance of the autophagic adaptor Sequestome-1 (hereafter, p62) for regulating inflammasome activation remains poorly understood. We report here that p62 restricts inflammasome availability and subsequent IL-1β secretion in macrophages infected with S. Typhimurium by targeting the inflammasome adaptor ASC for autophagic degradation. Importantly, loss of p62 resulted in impaired autophagy and increased IL-1β secretion, as well as IL-10 and IFN-β release. In summary, our results demonstrate a novel role for p62 in inducing autophagy and balancing major pro- and anti-inflammatory signaling pathways to prevent excessive inflammation during S. Typhimurium infection of macrophages.

Keywords:  ASC; IFN-I; IFN-β; IL-10; IL-1β; autophagy; inflammasome; p62

DOI:  https://doi.org/10.3389/fcimb.2025.1495567
Cell Death Differ. 2025 Apr 20.

Age-associated reduction in ER-Mitochondrial contacts impairs mitochondrial lipid metabolism and autophagosome formation in the heart.

Weilong Hong, Xue Zeng, Ruiyan Ma, Yu Tian, Huimin Miu, Xiaoping Ran, Rui Song, Zhenchun Luo, Dapeng Ju, Daqing Ma, Milad Ashrafizadeh, Sujit Kumar Bhutia, João Conde, Gautam Sethi, He Huang, Chenyang Duan.

The accumulation of dysfunctional giant mitochondria is a hallmark of aged cardiomyocytes. This study investigated the core mechanism underlying this phenomenon, focusing on the disruption of mitochondrial lipid metabolism and its effects on mitochondrial dynamics and autophagy, using both naturally aging mouse models and etoposide-induced cellular senescence models. In aged cardiomyocytes, a reduction in endoplasmic reticulum-mitochondrial (ER-Mito) contacts impairs lipid transport and leads to insufficient synthesis of mitochondrial phosphatidylethanolamine (PE). A deficiency in phosphatidylserine decarboxylase (PISD) further hinders the conversion of phosphatidylserine to PE within mitochondria, exacerbating the deficit of PE production. This PE shortage disrupts autophagosomal membrane formation, leading to impaired autophagic flux and the accumulation of damaged mitochondria. Modulating LACTB expression to enhance PISD activity and PE production helps maintain mitochondrial homeostasis and the integrity of aging cardiomyocytes. These findings highlight the disruption of mitochondrial lipid metabolism as a central mechanism driving the accumulation of dysfunctional giant mitochondria in aged cardiomyocytes and suggest that inhibiting LACTB expression could serve as a potential therapeutic strategy for mitigating cardiac aging and preserving mitochondrial function.

DOI: https://doi.org/10.1038/s41418-025-01511-w
Cell Res. 2025 Apr 21.

Lysosomal EGFR acts as a Rheb-GEF independent of its kinase activity to activate mTORC1.

Xiaobo He, Qiu-Xia Wang, Denghui Wei, Yujie Lin, Xia Zhang, Yuanzhong Wu, Xuexia Qian, Zhihao Lin, Beibei Xiao, Qinxue Wu, Zhen Wang, Fengtao Zhou, Zhihao Wei, Jingxuan Wang, Run Gong, Ruhua Zhang, Qingling Zhang, Ke Ding, Song Gao, Tiebang Kang.

Oncogenic mutations in EGFR often result in EGF-independent constitutive activation and aberrant trafficking and are associated with several human malignancies, including non-small cell lung cancer. A major consequence of EGFR mutations is the activation of the mechanistic target of rapamycin complex 1 (mTORC1), which requires EGFR kinase activity and downstream PI3K/AKT signaling, resulting in increased cell proliferation. However, recent studies have elucidated kinase-independent roles of EGFR in cell survival and cancer progression. Here, we report a cis mTORC1 activation function of EGFR that is independent of its kinase activity. Our results reveal that lysosomal localization of EGFR is critical to mTORC1 activation, where EGFR physically binds Rheb, acting as a guanine exchange factor (GEF) for Rheb, with its Glu804 serving as a potential glutamic finger. Genetic knock-in of EGFR-E804K in cells reduces the level of GTP-bound Rheb, and significantly suppresses mTORC1 activation, cell proliferation and tumor growth. Different tyrosine kinase inhibitors exhibit distinct effects on EGFR-induced mTORC1 activation, with afatinib, which additionally blocks EGFR's GEF activity, causing a much greater suppression of mTORC1 activation and cell growth, and erlotinib, which targets only kinase activity, resulting in only a slight decrease. Moreover, a novel small molecule, BIEGi-1, was designed to target both the Rheb-GEF and kinase activities of EGFR, and shows a strong inhibitory effect on the viability of cells harboring EGFR mutants. These findings unveil a fundamental event in cell growth and suggest a promising strategy against cancers with EGFR mutations.

DOI: https://doi.org/10.1038/s41422-025-01110-x
FEBS J. 2025 Apr 24.

Roles and applications of autophagy in guarding against environmental stress and DNA damage in Saccharomyces cerevisiae.

Tong Zhang, Yuping Lin, Ziteng Zhang, Zhen Wang, Fanli Zeng, Qinhong Wang.

  Saccharomyces cerevisiae (S. cerevisiae), a famous chassis cell factory, often faces various environmental stress conditions like extreme temperature, osmolarity, and nutrient starvation during the fermentation process. Additionally, chromosomal replication and genome editing-assisted metabolic engineering may cause DNA damage to S. cerevisiae. S. cerevisiae has evolved multiple elaborate mechanisms to fend against these adverse conditions. One of these "self-repair" mechanisms is autophagy, a ubiquitous "self-eating" mechanism that transports intracellular components to the lysosome/vacuole for degradation. Here, we reviewed the current state of our knowledge about the role and application of autophagy regulation in S. cerevisiae in response to environmental stress and genome damage, which may provide new strategies for developing robust industrial yeast and accelerating genome engineering.

Keywords:  Saccharomyces cerevisiae; autophagy; environmental stress; genome damage; genome editing

DOI:  https://doi.org/10.1111/febs.70112
Nat Commun. 2025 Apr 24. 16(1): 3860

Defective autophagy in CD4 T cells drives liver fibrosis via type 3 inflammation.

Rola Al Sayegh, Jinghong Wan, Charles Caër, Margot Azoulai, Maxime Gasperment, Sukriti Baweja, Marc-Anthony Chouillard, Janany Kandiah, Mathilde Cadoux, Morgane Mabire, Camille Pignolet, Tristan Thibault-Sogorb, Adel Hammoutene, Valérie Paradis, Loredana Saveanu, Rémy Nicolle, Hélène Gilgenkrantz, Emmanuel Weiss, Sophie Lotersztajn.

Conventional CD4 T cells represent a major source of inflammatory mediators that drive progression of chronic liver disease to fibrosis and to end-stage cirrhosis. Identification of T cell pathways that limits the inflammatory response could thus have therapeutic relevance. Here we show, using both human samples and mouse models, that autophagy is deficient in CD4 T cells from patients with advanced fibrosis, and that loss of autophagy following genomic deletion of ATG5 in T cells is associated with the emergence of pathogenic IL-17A + IFN-γ + Th17 T cells that drive liver fibrosis in mice. Mechanistically, liver CD4 T cells lacking autophagy display a Th17 glycolytic phenotype associated with enhanced type 3 cytokine (i.e., IL-17A and GM-CSF) release, shifting hepatic myofibroblasts, hepatocytes and macrophages toward a proinflammatory phenotype. We also show that autophagy can be rescued in CD4 T cells from patients with extensive liver fibrosis, leading to decreased frequency of pathogenic Th17 cells and reduced GM-CSF levels; in addition, limited fibrosis is observed in mice in which Rubicon, a negative regulator of autophagy, is deleted specifically in their T cells. Our findings thus implicate autophagy in CD4 T cells as a key therapeutic target to control inflammation-driven fibrosis during chronic liver injury.

DOI: https://doi.org/10.1038/s41467-025-59218-y
Acta Neuropathol Commun. 2025 Apr 24. 13(1): 83

Premature skeletal muscle aging in VPS13A deficiency relates to impaired autophagy.

Veronica Riccardi, Carlo Fiore Viscomi, Marco Sandri, Angelo D'Alessandro, Monika Dzieciatkowska, Daniel Stephenson, Enrica Federti, Andreas Hermann, Leonardo Salviati, Angela Siciliano, Immacolata Andolfo, Seth L Alper, Jacopo Ceolan, Achille Iolascon, Gaetano Vattemi, Adrian Danek, Ruth H Walker, Alexander Mensch, Markus Otto, Marcus Deschauer, Moritz Armbrust, Cristiane Beninca', Valentina Salari, Paolo Fabene, Kevin Peikert, Lucia De Franceschi.

  VPS13A disease (chorea-acanthocytosis), is an ultra-rare autosomal recessive neurodegenerative disorder caused by mutations of the VPS13A gene encoding Vps13A. Increased serum levels of the muscle isoform of creatine kinase associated with often asymptomatic muscle pathology are among the poorly understood early clinical manifestations of VPS13A disease. Here, we carried out an integrated analysis of skeletal muscle from Vps13a-/- mice and from VPS13A disease patient muscle biopsies. The absence of Vps13A impaired autophagy, resulting in pathologic metabolic remodeling characterized by cellular energy depletion, increased protein/lipid oxidation and a hyperactivated unfolded protein response. This was associated with defects in myofibril stability and the myofibrillar regulatory proteome, with accumulation of the myocyte senescence marker, NCAM1. In Vps13a-/- mice, the impairment of autophagy was further supported by the lacking effect of starvation alone or in combination with colchicine on autophagy markers. As a proof of concept, we showed that rapamycin treatment rescued the accumulation of terminal phase autophagy markers LAMP1 and p62 as well as NCAM1, supporting a connection between impaired autophagy and accelerated aging in the absence of VPS13A. The premature senescence was also corroborated by local activation of pro-inflammatory NF-kB-related pathways in both Vps13a-/- mice and patients with VPS13A disease. Our data link for the first time impaired autophagy and inflammaging with muscle dysfunction in the absence of VPS13A. The biological relevance of our mouse findings, supported by human muscle biopsy data, shed new light on the role of VPS13A in muscle homeostasis.

Keywords:  Autophagy; Energy; Inflammaging; Metabolome; NF-kB

DOI:  https://doi.org/10.1186/s40478-025-01997-y
Turk J Gastroenterol. 2025 Apr 21.

PPARγ Activates Autophagy by Suppressing the PI3K-AKT1-FOXO3 Signaling Pathway and thus Alleviates Hepatic Ischemia-Reperfusion Injury.

Xinyu Liu, Hengguan Cui, Xianqing Song, Weixing Shen, Bin Yan.

   Background/Aims: Hepatic ischemia-reperfusion injury (HIRI) refers to the damage caused by metabolic imbalance post-ischemia upon reperfusion, often occurring in scenarios like hemorrhagic shock, liver resection, and liver transplantation. Due to the complex nature of the mechanisms underlying metabolic imbalance, specific treatment options are lacking. Peroxisome proliferator activated receptor gamma (PPARγ) is a group of metabolic regulatory receptors that can influence HIRI by regulating autophagy, although the precise mechanism remains contentious.
Materials and Methods: In vivo and in vitro experiments were conducted to simulate hypoxic conditions, evaluating the effects of PPARγ overexpression plasmids, autophagy inhibitors, phosphatidylinositol 3-kinase (PI3K) activators, and PPARγ agonists on HIRI. The activation status of the PI3K-AKT1-FOXO3 signaling pathway, autophagy levels, inflammatory responses, and liver cell/organ damage were analyzed using western blot, ELISA, flow cytometry, H&E staining, and TUNEL experiments.
Results: Peroxisome proliferator activated receptor gamma can mitigate cell damage caused by hypoxia by activating autophagy, with the activation of autophagy being associated with the inhibition of the PI3K-AKT1-FOXO3 signaling pathway. Additionally, pretreatment of mice with the PPARγ agonist rosiglitazone can alleviate HIRI induced by ischemia by inhibiting the activation of the PI3K-AKT1-FOXO3 signaling pathway to induce autophagy.
Conclusion: Peroxisome proliferator activated receptor gamma inhibited the PI3K-AKT1-FOXO3 signaling pathway, which in turn activated autophagy to alleviate HIRI.

Keywords:  Autophagy; PI3K–AKT1–FOXO3; PPARγ; hepatic ischemia-reperfusion injury

DOI:  https://doi.org/10.5152/tjg.2025.24529
Cell Death Differ. 2025 Apr 23.

TTK promotes mitophagy by regulating ULK1 phosphorylation and pre-mRNA splicing to inhibit mitochondrial apoptosis in bladder cancer.

Kang Chen, Jinyu Chen, Yukun Cong, Qingliu He, Chunyu Liu, Jiawei Chen, Haoran Li, Yunjie Ju, Liang Chen, Yarong Song, Yifei Xing.

Bladder cancer (BC) remains a major global health challenge, with poor prognosis and limited therapeutic options in advanced stages. TTK protein kinase (TTK), a serine/threonine kinase, has been implicated in the progression of various cancers, but its role in BC has not been fully elucidated. In this study, we show that TTK is significantly upregulated in BC tissues and cell lines, correlating with poor patient prognosis. Functional assays revealed that TTK promotes proliferation and inhibits apoptosis of BC cells. Mechanistically, TTK enhances mitophagy by directly phosphorylating ULK1 at Ser477, thereby activating the ULK1/FUNDC1-mediated mitophagy pathway. TTK knockdown disrupts mitophagy, leading to impaired clearance of damaged mitochondria, excessive accumulation of mitochondrial reactive oxygen species (mtROS), and activation of mitochondrial apoptosis. Furthermore, TTK phosphorylates SRSF3 at Ser108, preventing ULK1 exon 5 skipping and maintaining ULK1 mRNA stability. These findings show that TTK plays a key role in maintaining mitophagy in BC cells. Targeting TTK could offer a promising new approach for BC treatment by disrupting mitophagy and inducing mitochondrial apoptosis.

DOI: https://doi.org/10.1038/s41418-025-01492-w
J Cell Biol. 2025 Jun 02. pii: e202412055. [Epub ahead of print]224(6):

Lysosomal TPC2 channels disrupt Ca2+ entry and dopaminergic function in models of LRRK2-Parkinson's disease.

Martina Gregori, Gustavo J S Pereira, Robert Allen, Nicholas West, Kai-Yin Chau, Xinjiang Cai, Matthew P Bostock, Stephen R Bolsover, Marco Keller, Chiao-Yin Lee, Si Hang Lei, Kirsten Harvey, Franz Bracher, Christian Grimm, Gaiti Hasan, Matthew E Gegg, Anthony H V Schapira, Sean T Sweeney, Sandip Patel.

Parkinson's disease results from degeneration of dopaminergic neurons in the midbrain, but the underlying mechanisms are unclear. Here, we identify novel crosstalk between depolarization-induced entry of Ca2+ and lysosomal cation release in maintaining dopaminergic neuronal function. The common disease-causing G2019S mutation in LRRK2 selectively exaggerated Ca2+ entry in vitro. Chemical and molecular strategies inhibiting the lysosomal ion channel TPC2 reversed this. Using Drosophila, which lack TPCs, we show that the expression of human TPC2 phenocopied LRRK2 G2019S in perturbing dopaminergic-dependent vision and movement in vivo. Mechanistically, dysfunction required an intact pore, correct subcellular targeting and Rab interactivity of TPC2. Reducing Ca2+ permeability with a novel biased TPC2 agonist corrected deviant Ca2+ entry and behavioral defects. Thus, both inhibition and select activation of TPC2 are beneficial. Functional coupling between lysosomal cation release and Ca2+ influx emerges as a potential druggable node in Parkinson's disease.

DOI: https://doi.org/10.1083/jcb.202412055
Schizophrenia (Heidelb). 2025 Apr 23. 11(1): 68

Aberrant aging-associated p62 autophagic cascade in biopsied olfactory neuronal cells from patients with psychosis.

Kun Yang, Koko Ishizuka, Toshifumi Tomoda, Akira Sawa.

Sequestosome-1/p62, a key mediator in the clearance of damaged organelles and macromolecules during autophagy, serves as a marker of biological aging. We demonstrate elevated p62 in biopsied neuronal cells in patients with psychosis compared to healthy controls. In healthy controls, p62-indicated biological/autophagic age is positively correlated with chronological age over time, whereas in patients, neuronal p62-indicated biological/autophagic age shows no correlation with chronological age, being significantly higher than chronological age from the onset of the disease.

DOI: https://doi.org/10.1038/s41537-025-00617-x
Front Physiol. 2025 ;16 1572139

Trehalose induces bladder smooth muscle hypercontractility in mice: involvement of oxidative stress and cellular senescence.

Guilherme Lemos, Cícera Madri Alves de Souza Fernandes, Ingrid Kazue Mizuno Watanabe, Maria Andreia Delbin, Fábio Henrique Silva, Fabiano Beraldi Calmasini.

  Autophagy, a conserved catabolic process, is critical for cellular homeostasis and its dysregulation has been implicated in a number of conditions including hypertension, obesity and bladder dysfunctions. The autophagy inducer trehalose has shown promise in treating diseases; however, some studies have reported detrimental effects in vascular tissue under health conditions. In the bladder, the effects of trehalose remain unclear. Therefore, in the present study, male C57BL6/JUnib mice (8 weeks old) were divided into control and trehalose-treated groups (120 mg/mouse/day via gavage) for 4 weeks. After treatment, bladders were harvested for functional, biochemical, and molecular analyses. The trehalose treatment increased the bladder smooth muscle (BSM) contractility to carbachol (CCh), without altering relaxation response to isoproterenol. The CCh-induced BSM hypercontractility was completely abolished by the in vitro incubation of apocynin and diphenyleneiodonium (DPI), implicating NADPH oxidase-derived reactive oxygen species (ROS) on this process. Accordingly, increased levels of superoxide anion (O2-) were found in the urothelial layer, but not in BSM, of trehalose-treated mice. Trehalose also increased senescence-associated β-galactosidase activity in the bladder but failed to upregulate autophagy-related proteins LAMP1 and Beclin-1 in the bladder. Collectively, we show for the first time that trehalose induces BSM hypercontractility in mice, linked to increased levels of O2- and senescent cell, independently of autophagy activation. Therefore, trehalose administration is an effective model for studying BSM hypercontractility in mice, particularly associated with oxidative stress and cellular senescence.

Keywords:  NADPH oxidase; autophagy; overactive bladder; reactive oxygen species; superoxide anion

DOI:  https://doi.org/10.3389/fphys.2025.1572139
Sci Rep. 2025 Apr 21. 15(1): 13805

Autophagy inhibition enhances antifibrotic potential of placental mesenchymal stem cells of fetal origin via regulating TGF-β1 mediated protein degradation of HGF.

Wei Zhou, Jing Wang, Lu Ding, Ruizhi Cai, Jie Cheng, Panpan Liang, Yongzhao Zhu, Zaiqi Zhang.

  Mesenchymal stem cell (MSC) therapy represents a promising strategy for pulmonary fibrosis (PF) treatment, with hepatocyte growth factor (HGF) serving as a key mediator of MSC-mediated protection. However, the therapeutic efficacy of MSCs is limited by the complex PF microenvironment, and the mechanisms underlying this limitation remain unclear. This study investigates how the PF pathological microenvironment modulates the antifibrotic potential of placental mesenchymal stem cells of fetal origin (fPMSCs) through HGF regulation and elucidates the molecular mechanisms involved. Morphological analysis, flow cytometry, and multilineage differentiation assays were employed to characterize fPMSCs. Transforming growth factor-β1 (TGF-β1) was employed to simulate the PF microenvironment and activate fPMSCs in vitro. ELISA and Western blotting were used to analyze HGF expression, autophagy markers, and Smad signaling. Autophagosome formation was visualized via confocal microscopy and transmission electron microscopy. Co-immunoprecipitation (Co-IP) assays were performed to assess the interaction between p62 and HGF. The antifibrotic function of fPMSCs was further evaluated using a transwell co-culture system with MRC-5 fibroblasts in vitro and a bleomycin-induced PF mouse model in vivo. Phenotypic characterization confirmed that fPMSCs exhibited canonical MSC morphology, expressed CD73/CD90/CD105, lacked CD14/CD34/CD45/HLA-DR, and differentiated into adipogenic, osteogenic, and chondrogenic lineages. TGF-β1 treatment robustly downregulated the antifibrotic capacity, HGF protein expression, and paracrine secretion in fPMSCs. Recombinant HGF enhanced antifibrotic effects, while an HGF-neutralizing antibody abolished them. TGF-β1 induced autophagy in fPMSCs, promoting HGF degradation via p62 interaction and impairing antifibrotic function in vitro and in vivo. Mechanistically, Smad3 phosphorylation mediated the regulation of autophagy and HGF expression in TGF-β1-treated fPMSCs. Our findings demonstrate that TGF-β1 impairs the antifibrotic function of fPMSCs via autophagy-dependent HGF degradation and Smad3 signaling. Conversely, autophagy inhibition restores HGF levels and enhances fPMSCs' therapeutic efficacy in a preclinical PF model. Targeting autophagy inhibition emerges as a promising therapeutic strategy to counteract pulmonary fibrosis.

Keywords:  Autophagy; HGF; Placental mesenchymal stem cells of fetal origin; Pulmonary fibrosis; TGF-β1

DOI:  https://doi.org/10.1038/s41598-025-97054-8
Int Immunopharmacol. 2025 Apr 19. pii: S1567-5769(25)00661-7. [Epub ahead of print]156 114671

Urolithin A alleviates radiation pneumonitis by activating PINK1/PRKN-mediated Mitophagy.

Anqi Zhang, Shilan Luo, Peng Li, Lu Meng, Litang Huang, Hongxia Cheng, Chenhui Zhao, Hongbin Tu, Xiaomei Gong.

   BACKGROUND: Radiation pneumonitis (RP) is a common and severe complication of radiotherapy, whose pathogenesis involves complex inflammatory responses and cellular damage. Despite its clinical significance, effective treatments remain limited. This study investigates the role of radiation-induced PINK1/PRKN-mediated mitophagy and type I interferon responses in RP and evaluates the therapeutic potential of Urolithin A (UA) in regulating inflammation through mitophagy activation.
METHODS: We established RP mouse models (20 Gy thoracic irradiation) and radiation-induced BEAS-2B cell models (6 Gy). We systematically investigated mitochondrial damage, mtRNA release, RIG-I/MDA5-MAVS pathway activation, and PINK1/PRKN-mediated mitophagy changes. Moreover, the effects of UA and the mitophagy inhibitor Mdivi-1 on inflammation and lung injury were analyzed.
RESULTS: Radiation significantly caused mitochondrial damage in lung tissues, inducing mtRNA release and RIG-I/MDA5-MAVS-mediated type I interferon response. PINK1/PRKN-mediated mitophagy was significantly enhanced, clearing damaged mitochondria and reducing cytosolic mtRNA release, thereby suppressing inflammation. Pharmacological activation of mitophagy with UA markedly improved lung pathology, reduced inflammatory cytokine levels, and inhibited excessive activation of the RIG-I/MDA5-MAVS pathway. Conversely, the knockdown of PINK1 or PRKN weakened the protective effects of UA. Both in vitro and in vivo, UA reduced radiation-induced inflammation and improved lung tissue structure and function through mitophagy.
CONCLUSIONS: Radiation-induced mtRNA release activates the RIG-I/MDA5-MAVS-mediated type I interferon response, driving inflammation in RP. PINK1/PRKN-mediated mitophagy significantly alleviates inflammation by reducing cytosolic mtRNA release. As a mitophagy inducer, UA demonstrates therapeutic potential for RP, providing a new direction for the development of anti-inflammatory strategies.

Keywords:  Inflammation; Mitophagy; PINK1/PRKN; Radiation pneumonitis; Urolithin A

DOI:  https://doi.org/10.1016/j.intimp.2025.114671
PLoS One. 2025 ;20(4): e0321752

Curcumin ameliorates aging-induced blood-testis barrier disruption by regulating AMPK/mTOR mediated autophagy.

Chen Xue, Zhenxing Yan, Wenjing Cheng, Dong Zhang, Rong Zhang, Hongwei Duan, Lihong Zhang, Xiaofei Ma, Junjie Hu, Jian Kang, Xiaojun Ma.

The blood-testis barrier (BTB) is composed of tight junctions (TJ) between adjacent Sertoli cells (SCs) and is crucial for sperm growth and development. Aging-induced TJ impairment is closely related to testicular dysfunction. Curcumin, a natural compound, has been widely demonstrated to have a wide range of pharmacological activities, but its regulatory effects on tight junction damage in the testis remain unclear. We here explored the effect of curcumin on TJ function and its underlying molecular mechanism by using D-galactose (D-gal)-induced mouse testis and mouse testicular SCs (TM4) aging models in vitro. In this study, D-gal increased the expression of aging-related proteins p16 and p21, whereas significantly decreased the expression of TJ proteins (ZO-1, Claudin-4, Claudin-7, and Occludin). In addition, curcumin restored the adverse effects of D-gal in the SCs. Autophagy is a degradation system for maintaining cell renewal and homeostasis. D-gal significantly decreased the autophagy level, whereas curcumin restored the effect of D-gal. Using chloroquine (CQ), an inhibitor of autophagy, and rapamycin (RAPA), an activator of autophagy, it was demonstrated that autophagy plays a key role in curcumin amelioration of TJ injury in testicular SCs. Further studies unveiled that autophagy activation was mediated through the AMPK/mTOR pathway. In conclusion, curcumin ameliorates aging-induced TJ damage through AMPK/mTOR signaling pathway-regulated autophagy. This study thus clearly identifies a novel action mechanism of curcumin in the treatment of age-related male reproductive disorders.

DOI: https://doi.org/10.1371/journal.pone.0321752
Cell Signal. 2025 Apr 19. pii: S0898-6568(25)00228-1. [Epub ahead of print]132 111815

Biliverdin alleviates cerebral ischemia-reperfusion injury by regulating the P4hb/MAPK/mTOR pathway to inhibit autophagy.

Huan Jiang, Wenya Bai, Yuan Yang, Guilin Zhou, Junjie Li, Xuelian Li, Xiaohong Wan, Jianlin Shao.

   BACKGROUND: Biliverdin (BV) exhibits anti-inflammatory and antioxidative effects. Autophagy activation is crucial in the pathogenesis of cerebral ischemia-reperfusion injury (CIRI). This study aimed to investigate whether BV could ameliorate CIRI by regulating autophagy.
METHODS: A middle cerebral artery occlusion-reperfusion (MCAO/R) model in Sprague-Dawley (SD) rats and an oxygen-glucose deprivation/reoxygenation (OGD/R) model in PC12 cells were employed to explore the neuroprotective effects of BV and its underlying mechanisms. In these rats, once BV was administered post-MCAO/R, its treatment efficacy and underlying mechanisms were evaluated through behavioral, morphological, and molecular analyses. Alternatively, for PC12 cells, following successful OGD/R modeling, BV, autophagy activator rapamycin, prolyl 4-hydroxylase beta (P4hb) knockdown or overexpression, and the specific inhibitors of three classic autophagy pathways were applied. Cell viability (using CCK8 assay), Calcein/PI staining, autophagosome staining (using MDC assay), reverse transcription quantitative polymerase chain reaction, and western blot were subsequently carried out to investigate the mechanisms by which BV ameliorates CIRI.
RESULTS: BV alleviated CIRI by inhibiting autophagy. Further investigation suggested that BV downregulated P4hb expression. In vitro experiments showed that P4hb knockdown reduced autophagy in post-CIRI cells, while its overexpression reversed the effects of BV. Rescue experiments indicated that MAPK pathway inhibitors counteracted the effects of P4hb overexpression on autophagy post-CIRI.
CONCLUSION: BV improves CIRI by regulating the P4hb/MAPK/mTOR signaling pathway to inhibit autophagy, offering a novel therapeutic strategy for ischemic stroke.

Keywords:  Autophagy; Biliverdin; Cerebral ischemia-reperfusion injury; MAPK/mTOR signaling pathway; Oxygen-glucose deprivation/reoxygenation injury; Prolyl 4-hydroxylase beta

DOI:  https://doi.org/10.1016/j.cellsig.2025.111815
Autophagy Rep. 2025 ;pii: 2473765. [Epub ahead of print]4(1):

High throughput screening assay for the identification of ATF4 and TFEB activating compounds.

Daniel J Pfau, Ruslana Bryk.

  Macrophages act to defend against infection, but can fail to completely prevent bacterial replication and dissemination in an immunocompetent host. Recent studies have shown that activation of a host transcription factor, TFEB, a regulator of lysosomal biogenesis, could restrict intramacrophage replication of the human pathogen Mycobacterium tuberculosis and synergize with suboptimal levels of the antibiotic rifampin to reduce bacterial loads. Currently available small molecule TFEB activators lack selectivity and potency, but could be potentially useful in a variety of pathological conditions with suboptimal lysosomal activity. TFEB nuclear translocation and activation depend on its phosphorylation status which is controlled by multiple cellular pathways. We devised a whole cell, high throughput screening assay to identify small molecules that activate TFEB by establishing a stably transfected HEK293T reporter cell line for ATF4, a basic leucine zipper transcription factor induced by stress response and activated in parallel to TFEB. We optimized its use in vitro using compounds that target endoplasmic reticulum stress and intracellular calcium signaling. We report results from screening the commercially available LOPAC library and the Selleck Chemicals library modified to include only FDA-approved drugs and clinical research compounds. We identified twenty-one compounds across six clinical use categories that activate ATF4, and confirmed that two proteasome inhibitors promote TFEB activation. The results of this study provide an assay that could be used to screen for small molecules that activate ATF4 and TFEB and a potential list of compounds identified as activators of the ATF4 transcription factor in response to cellular stress.

Keywords:  host-directed therapy; macrophage; mycobacteria; stress response; tuberculosis

DOI:  https://doi.org/10.1080/27694127.2025.2473765
Sci Adv. 2025 Apr 25. 11(17): eadq6077

Loss of intracellular ATP affects axoplasmic viscosity and pathological protein aggregation in mammalian neurons.

Laurent Guillaud, Anna Garanzini, Sarah Zakhia, Sandra De la Fuente, Dimitar Dimitrov, Susan Boerner, Marco Terenzio.

Neurodegenerative diseases display synaptic deficits, mitochondrial defects, and protein aggregation. We show that intracellular adenosine triphosphate (ATP) regulates axoplasmic viscosity and protein aggregation in mammalian neurons. Decreased intracellular ATP upon mitochondrial inhibition leads to axoterminal cytosol, synaptic vesicles, and active zone component condensation, modulating the functional organization of mouse glutamatergic synapses. Proteins involved in the pathogenesis of Parkinson's disease (PD), Alzheimer's disease (AD), and amyotrophic lateral sclerosis (ALS) condensed and underwent ATP-dependent liquid phase separation in vitro. Human inducible pluripotent stem cell-derived neurons from patients with PD and ALS displayed reduced axoplasmic fluidity and decreased intracellular ATP. Last, nicotinamide mononucleotide treatment successfully rescued intracellular ATP levels and axoplasmic viscosity in neurons from patients with PD and ALS and reduced TAR DNA-binding protein 43 (TDP-43) aggregation in human motor neurons derived from a patient with ALS. Thus, our data suggest that the hydrotropic activity of ATP contributes to the regulation of neuronal homeostasis under both physiological and pathological conditions.

DOI: https://doi.org/10.1126/sciadv.adq6077
Sci Signal. 2025 Apr 22. 18(883): eado3473

Re-epithelialization of cancer cells increases autophagy and DNA damage: Implications for breast cancer dormancy and relapse.

Diana Drago-Garcia, Suvendu Giri, Rishita Chatterjee, Arturo Simoni-Nieves, Maha Abedrabbo, Alessandro Genna, Mary Luz Uribe Rios, Moshit Lindzen, Arunachalam Sekar, Nitin Gupta, Noa Aharoni, Tithi Bhandari, Agalyan Mayalagu, Luisa Schwarzmüller, Nooraldeen Tarade, Rong Zhu, Harsha-Raj Mohan-Raju, Feride Karatekin, Francesco Roncato, Yaniv Eyal-Lubling, Tal Keidar, Yam Nof, Nishanth Belugali Nataraj, Karin Shira Bernshtein, Bettina Wagner, Nishanth Ulhas Nair, Neel Sanghvi, Ronen Alon, Rony Seger, Eli Pikarsky, Sara Donzelli, Giovanni Blandino, Stefan Wiemann, Sima Lev, Ron Prywes, Dalit Barkan, Oscar M Rueda, Carlos Caldas, Eytan Ruppin, Yosef Shiloh, Maik Dahlhoff, Yosef Yarden.

Cellular plasticity mediates tissue development as well as cancer growth and progression. In breast cancer, a shift to a more epithelial phenotype (epithelialization) underlies a state of reversible cell growth arrest called tumor dormancy, which enables drug resistance, tumor recurrence, and metastasis. Here, we explored the mechanisms driving epithelialization and dormancy in aggressive mesenchymal-like breast cancer cells in three-dimensional cultures. Overexpressing either of the epithelial lineage-associated transcription factors OVOL1 or OVOL2 suppressed cell proliferation and migration and promoted transition to an epithelial morphology. The expression of OVOL1 (and of OVOL2 to a lesser extent) was regulated by steroid hormones and growth factors and was more abundant in tumors than in normal mammary cells. An uncharacterized and indirect target of OVOL1/2, C1ORF116, exhibited genetic and epigenetic aberrations in breast tumors, and its expression correlated with poor prognosis in patients. We further found that C1ORF116 was an autophagy receptor that directed the degradation of antioxidant proteins, including thioredoxin. Through C1ORF116 and unidentified mediators, OVOL1 expression dysregulated both redox homeostasis (in association with increased ROS, decreased glutathione, and redistribution of the transcription factor NRF2) and DNA damage and repair (in association with increased DNA oxidation and double-strand breaks and an altered interplay among the kinases p38-MAPK, ATM, and others). Because these effects, as they accumulate in cells, can promote metastasis and dormancy escape, the findings suggest that OVOLs not only promote dormancy entry and maintenance in breast cancer but also may ultimately drive dormancy exit and tumor recurrence.

DOI: https://doi.org/10.1126/scisignal.ado3473