bims-kishpe 2024-10-27 papers

bims-kishpe

Biomed News

on HSP70 role in hypoxia and metabolism in ECs

Issue of 2024‒10‒27
23 papers selected by
Alia Ablieh, Universität Heidelberg

Chronic hypoxia for the adaptation of extracellular vesicle phenotype.
Hypoxia-inducible Factor-1α Pathway in Cerebral Ischemia: From Molecular Mechanisms to Therapeutic Targets.
MiR-150-5p inhibits cell proliferation and metastasis by targeting FTO in osteosarcoma.
m6A demethylase FTO transcriptionally activated by SP1 improves ischemia reperfusion-triggered acute kidney injury by activating Ambra1/ULK1-mediated autophagy.
Unraveling the role of HIF and epigenetic regulation in pulmonary arterial hypertension: implications for clinical research and its therapeutic approach.
Increased TRPV4 Channel Expression Enhances and Impairs Blood Vessel Function in Hypertension.
MYL9 binding with MYO19 suppresses epithelial-mesenchymal transition in non-small cell lung cancer.
MAT1A activation of glycolysis to promote NSCLC progression depends on stabilizing CCND1.
Nitric Oxide-Dependent Regulation of Oxygen-Related Processes in a Rat Model of Lead Neurotoxicity: Influence of the Hypoxia Resistance Factor.
Heterogeneity of Endothelial Cells Impacts the Functionality of Human Pancreatic In Vitro Models.
Epigenome Mapping in Quiescent Cells Reveals a Key Role for H3K4me3 in Regulation of RNA Polymerase II Activity.
Targeting catalase in cancer.
High glucose elevates intracellular calcium level and induces ferroptosis in glomerular endothelial cells through the miR-223-3p/ITPR3 pathway.
Roles of Hypoxia-Inducible Factor-Prolyl Hydroxylases in Aging and Disease.
HNF4A-AS1 inhibits the progression of hepatocellular carcinoma by promoting the ubiquitin-modulated degradation of PCBP2 and suppressing the stability of ARG2 mRNA.
Vascular inflammaging: Endothelial CEACAM1 expression is upregulated by TNF-α via independent activation of NF-κB and β-catenin signaling.
Going with the flow: New insights regarding flow induced K+ secretion in the distal nephron.
Novel PPAR-γ agonists as potential neuroprotective agents against Alzheimer's disease: rational design, synthesis, in silico evaluation, PPAR-γ binding assay and transactivation and expression studies.
Foxd3/SLC5A6 axis regulates apoptosis in LUAD cells by controlling mitochondrial biotin uptake.
Non-electrophilic NRF2 activators promote wound healing in human keratinocytes and diabetic mice and demonstrate selective downstream gene targeting.
Mlf mediates proteotoxic response via formation of cellular foci for protein folding and degradation in Giardia.
Effects of hyperglycemia on airway epithelial barrier function in WT and CF 16HBE cells.
Exploring the molecular pathways of the activation process in PPARγ recurrent bladder cancer mutants.

Sci Rep. 2024 Oct 24. 14(1): 25189

Chronic hypoxia for the adaptation of extracellular vesicle phenotype.

Chris S Pridgeon, Kerttu Airavaara, Julia Monola, Alisa Jokela, Daniel Palmer, Marjo Yliperttula, Riina Harjumäki.

Variations in oxygen level affect the phenotype of cells and extracellular vesicles (EVs). Depending on the metabolic oxygen demand of cells, hypoxic cell culture can produce conditions more like those found in vivo, and with appropriate oxygen levels, mimic hypoxic tumours. However, most previous experiments studying both EVs and the effects of hypoxia on cells use periods of 72 h or less of hypoxia. We hypothesised that this was insufficient time for adaptation to hypoxic conditions both for EVs and cells which may skew the results of such studies. In this study, the effects of acute (72 h) and chronic hypoxia (> 2 weeks) on the phenotype of HepG2 and PC3 cells and their EVs were examined. Cells could be cultured normally under chronic hypoxic conditions and cryopreserved and recovered. The effects of hypoxia on EV phenotype are slow to establish and dependent on cell line. In PC3 cells, the greatest change in phenotype and increase in EV production occurred only with chronic hypoxic culture. In HepG2 cells, the number of EVs produced was insensitive to hypoxic culture and the greatest changes in protein expression were observed after acute hypoxic culture. Nonetheless, biphasic changes in EV phenotype were detected in both cell types in response to either acute or chronic hypoxia. These results indicate that for cells which do not induce consumptive oxygen depletion, prolonged hypoxic culture is required for complete adaptation.

DOI: https://doi.org/10.1038/s41598-024-73453-1
CNS Neurol Disord Drug Targets. 2024 Oct 18.

Hypoxia-inducible Factor-1α Pathway in Cerebral Ischemia: From Molecular Mechanisms to Therapeutic Targets.

Veerta Sharma, Thakur Gurjeet Singh.

  INTRODUCTION: Ischemic injury to the brain can result in a variety of life-threatening conditions, mortality, or varying degrees of disability. Hypoxia-inducible factor 1α (HIF 1α), an oxygen- sensitive transcription factor that controls the adaptive metabolic response to hypoxia, is a critical constituent of cerebral ischemia. It participates in numerous processes, such as metabolism, proliferation, and angiogenesis, and plays a major role in cerebral ischemia.METHODS: Through the use of a number of different search engines like Scopus, PubMed, Bentham, and Elsevier databases, a literature review was carried out for investigating the pharmacological modulation of HIF-1α pathways for the treatment of cerebral ischemia.
RESULTS: Various signalling pathways, such as Mitogen-activated protein kinase (MAPK), Janus kinase/ signal transducers and activators (JAK/STAT), Phosphoinositide-3-kinase (PI3-K), and cAMPresponse element binding protein (CREB) play a vital role in modulation of HIF-1α pathway, which helps in preventing the pathogenesis of cerebral ischemia.
CONCLUSION: The pharmacological modulation of the HIF-1α pathway via various molecular signalling pathways, such as PI3-K, MAPK, CREB, and JAK/STAT activators, offer a promising prospect for future interventions and treatment for cerebral ischemia.

Keywords:  Hypoxia-inducible factor-1α; cerebral ischemia; hypoxia response elements; ischemic stroke.; neurotransmitters

DOI:  https://doi.org/10.2174/0118715273324551241008111827
Oncol Res. 2024 ;32(11): 1777-1789

MiR-150-5p inhibits cell proliferation and metastasis by targeting FTO in osteosarcoma.

Lichen Xu, Pan Zhang, Guiqi Zhang, Zhaoliang Shen, Xizhuang Bai.

  Background: Osteosarcoma (OS), recognized as the predominant malignant tumor originating from bones, necessitates an in-depth comprehension of its intrinsic mechanisms to pinpoint novel therapeutic targets and enhance treatment methodologies. The role of fat mass and obesity-associated (FTO) in OS, particularly its correlation with malignant traits, and the fundamental mechanism, remains to be elucidated.Materials and Methods: 1. The FTO expression and survival rate in tumors were analyzed. 2. FTO in OS cell lines was quantified utilizing western blot and PCR. 3. FTO was upregulated and downregulated separately in MG63. 4. The impact of FTO on the proliferation and migration of OS cells was evaluated using CCK-8, colony formation, wound healing, and Transwell assays. 5. The expression of miR-150-5p in OS cells-derived exosomes was identified. 6. The binding of miR-150-5p to FTO was predicted by TargetScan and confirmed by luciferase reporter assay. 7. The impact of exosome miR-150-5p on the proliferation and migration of OS cells was investigated.
Results: The expression of FTO was higher in OS tissues compared to normal tissues correlating with a worse survival rate. Furthermore, the downregulation of FTO significantly impeded the growth and metastasis of OS cells. Additionally, miR-150-5p, which was downregulated in both OS cells and their derived exosomes, was found to bind to the 3'-UTR of FTO through dual luciferase experiments. Exosomal miR-150-5p was found to decrease the expression of FTO and inhibit cell viability.
Conclusions: We identified elevated levels of FTO in OS, which may be attributed to insufficient miR-150-5p levels in both the cells and exosomes. It suggests that the dysregulation of miR-150-5p and its interaction with FTO could potentially promote the development of OS.

Keywords:  Cell metastasis; Cell proliferation; Exosome; Fat mass and obesity associated (FTO); MiR-150-5p; Oosteosarcoma (OS)

DOI:  https://doi.org/10.32604/or.2024.047704
FASEB J. 2024 Oct 31. 38(20): e70118

m6A demethylase FTO transcriptionally activated by SP1 improves ischemia reperfusion-triggered acute kidney injury by activating Ambra1/ULK1-mediated autophagy.

Yan Chen, Yuanfei Liu, Weiping Tu, Yanxia Chen, Chengyun Xu, Chong Huang.

  Ischemia reperfusion (I/R) was considered as one of main causes of acute kidney injury (AKI). However, the exact mechanism remains unclear. Here, this study aimed to investigate the role and mechanism of the m6A demethylase fat mass and obesity-associated (FTO) protein in I/R-induced AKI. HK-2 cells and SD rats were utilized to establish hypoxia/reoxygenation (H/R) or I/R induced AKI models. The changes of RNAs and proteins were quantified using RT-qPCR, western blot, and immunofluorescence assays, respectively. Cell proliferation and apoptosis were assessed by CCK-8 and flow cytometry. Interactions between molecules were investigated using RIP, ChIP, Co-IP, RNA pull-down, and dual luciferase reporter assays. Global m6A quantification was evaluated by kits. TUNEL and HE staining were employed for histopathological examinations. Oxidative stress-related indicators and renal function were determined using ELISA assays. The FTO expression was downregulated in H/R-induced HK-2 cells and renal tissues from I/R-induced rats. Overexpression of FTO improved the cell viability but repressed apoptosis and oxidative stress in H/R-treated HK-2 cells, as well as enhanced renal function and alleviated kidney injury in I/R rats. Notably, the FTO overexpression significantly increased autophagy-related LC3 and ULK1 levels. When autophagy was inhibited, the protective effects of FTO in AKI were diminished. Notably, Ambra1, a crucial regulator of autophagy, was repressed in H/R-induced HK-2 cells. However, the FTO overexpression restored the Ambra1 expression by reducing m6A modification of its mRNA. SP1, acting as an upstream transcription factor, directly interacts with the FTO promoter to enhance FTO expression. Knockdown of SP1 or Ambra1 suppressed the beneficial effects of FTO upregulation on autophagy and oxidative stress injury in H/R-stimulated cells. FTO, transcriptionally activated by SP1, promoted autophagy by upregulating Ambra1/ULK1 signaling, thereby inhibiting oxidative stress and kidney injury. These findings may provide some novel insights for AKI treatment.

Keywords:  Ambra1; FTO; SP1; ULK1; acute kidney injury; autophagy

DOI:  https://doi.org/10.1096/fj.202400132RRR
Front Med (Lausanne). 2024 ;11 1460376

Unraveling the role of HIF and epigenetic regulation in pulmonary arterial hypertension: implications for clinical research and its therapeutic approach.

Ankita Mitra, Dan Yi, Zhiyu Dai, Vinicio de Jesus Perez.

  Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling with high pulmonary pressure, which ultimately leads to right heart failure and premature death. Emerging evidence suggests that both hypoxia and epigenetics play a pivotal role in the pathogenesis of PAH development. In this review article, we summarize the current developments in regulation of hypoxia inducible factor (HIF) isoforms in PAH vascular remodeling and the development of suitable animal models for discovery and testing of HIF pathway-targeting PAH therapeutics. In addition, we also discuss the epigenetic regulation of HIF-dependent isoforms in PAH and its therapeutic potential from a new perspective which highlights the importance of HIF isoform-specific targeting as a novel salutary strategy for PAH treatment.

Keywords:  animal model; epigenetics; hypoxia inducible factor; pulmonary arterial hypertension; therapeutics

DOI:  https://doi.org/10.3389/fmed.2024.1460376
Hypertension. 2024 Oct 23.

Increased TRPV4 Channel Expression Enhances and Impairs Blood Vessel Function in Hypertension.

Xun Zhang, Charlotte Buckley, Matthew D Lee, Christine Salaun, Margaret MacDonald, Calum Wilson, John G McCarron.

  BACKGROUND: Endothelial cell TRPV4 (transient receptor potential vanilloid 4) channels provide a control point that is pivotal in regulating blood vessel diameter by mediating the Ca2+-dependent release of endothelial-derived vasoactive factors. In hypertension, TRPV4-mediated control of vascular function is disrupted, but the underlying mechanisms and precise physiological consequences remain controversial.METHODS: Here, using a comprehensive array of methodologies, endothelial TRPV4 channel function was examined in intact mesenteric resistance arteries from normotensive Wistar-Kyoto and spontaneously hypertensive rats.
RESULTS: Our results show there is a notable shift in vascular reactivity in hypertension characterized by enhanced endothelium-dependent vasodilation at low levels of TRPV4 channel activation. However, at higher levels of TRPV4 activity, this vasodilatory response is reversed, contributing to the aberrant vascular tone observed in hypertension. The change in response, from dilation to constriction, was accompanied by a shift in intracellular Ca2+ signaling modalities arising from TRPV4 activity. Oscillatory TRPV4-evoked IP3 (inositol triphosphate)-mediated Ca2+ release, which underlies dilation, decreased, while the contraction inducing sustained Ca2+ rise, arising from TRPV4-mediated Ca2+ influx, increased. Our findings also reveal that while the sensitivity of endothelial cell TRPV4 to activation was unchanged, expression of the channel is upregulated and IP3 receptors are downregulated in hypertension.
CONCLUSIONS: These data highlight the intricate interplay between endothelial TRPV4 channel expression, intracellular Ca2+ signaling dynamics, and vascular reactivity. Moreover, the data support a new unifying hypothesis for the vascular impairment that accompanies hypertension. Specifically, endothelial cell TRPV4 channels play a dual role in modulating blood vessel function in hypertension.

Keywords:  TRPV cation channels; endothelial cells; hypertension; inositol 1,4,5-trisphosphate receptors; vasodilation

DOI:  https://doi.org/10.1161/HYPERTENSIONAHA.124.23092
Physiol Genomics. 2024 Oct 22.

MYL9 binding with MYO19 suppresses epithelial-mesenchymal transition in non-small cell lung cancer.

Meiling Sheng, Qunzhi Wang, Yabo Lou, Yuanchao Xiao, Xiaoming Wu.

  BACKGROUND: The elusive function of myosin light chain 9 (MYL9) in cancer is an area ripe for further investigation.METHODS: Bioinformatics was utilized to compare the expression levels of MYL9 in non-small cell lung cancer (NSCLC) and normal tissues. Gene set enrichment analysis (GSEA) was employed to investigate the pathways associated with MYL9. BioGRID database was utilized to screen for potential targets of MYL9. The expression of MYL9 and myosin 19 (MYO19) mRNA was quantified using quantitative reverse transcriptase PCR. Cell migration was assessed using a scratch wound healing assay. Protein levels of MYL9, MYO19, and epithelial-mesenchymal transition (EMT) biomarkers were examined using western blot (WB). EpCAM expression in different cell groups was profiled using flow cytometry analysis. Co-immunoprecipitation assays were performed to determine the binding affinity between MYL9 and MYO19. Additionally, direct protein interaction between MYL9 and MYO19 was explored using a GST-pull-down assay.
RESULTS: In NSCLC patients, MYL9 was significantly downregulated in vivo and in cell cultures, showing high enrichment in the EMT pathway. Scratch assays indicated its inhibitory effect on cell migration. Western blotting revealed that MYL9 suppresses EMT marker protein expression in NSCLC cells. Flow cytometry showed that MYL9 reduced EpCAM levels on the cell surface. MYO19 was identified as a potential target of MYL9 through CoIP and GST-pull-down assays. Rescue experiments demonstrated that MYO19 enhances cell migration, EMT marker expression, and EpCAM levels, but these effects were countered by MYL9 overexpression.
CONCLUSION: MYL9 impedes the migration and EMT in NSCLC cells by binding to MYO19.

Keywords:  MYL9; MYO19; epithelial-mesenchymal transition; non-small cell lung cancer

DOI:  https://doi.org/10.1152/physiolgenomics.00119.2024
Cell Death Dis. 2024 Oct 22. 15(10): 768

MAT1A activation of glycolysis to promote NSCLC progression depends on stabilizing CCND1.

Shengping Shen, Ruili Liu, Jiazheng Huang, Yingjia Sun, Qiang Tan, Qingquan Luo, Ruijun Liu.

Non-small cell lung cancer (NSCLC) remains a cause for concern as the leading cause of cancer-related death worldwide. Amidst ongoing debates on the role and mechanisms of methionine adenosyltransferase 1A (MAT1A) in cancer, our study sheds light on its significance in NSCLC. Leveraging TCGA database and immunohistochemical staining, we systematically analyzed MAT1A expression in NSCLC, uncovering its marked upregulation. To unravel the functional and mechanistic underpinnings, we implemented stable knockdown of MAT1A in NSCLC cell lines. Our findings converged to demonstrate that suppression of MAT1A expression effectively impeded the proliferation and migratory capabilities of NSCLC cells, while concurrently enhancing apoptosis. Mechanistically, we discovered that MAT1A depletion accelerated the degradation of CCND1, a key cell cycle regulator, through S-phase kinase-associated protein 2 (SKP2)-mediated ubiquitination. Notably, CCND1 emerged as a crucial MAT1A partner, jointly orchestrating glycolytic metabolism in NSCLC cells. This intricate interplay suggests that MAT1A promotes NSCLC progression by safeguarding CCND1 protein stability and activating glycolytic pathways, thereby sustaining tumorigenesis. In summary, our study not only identifies MAT1A as a prognostic marker for poor survival in NSCLC patients but also elucidates its mechanistic contributions to cancer progression. These findings pave the way for the development of targeted therapies aimed at disrupting the deleterious MAT1A-CCND1-glycolysis axis in NSCLC.

DOI: https://doi.org/10.1038/s41419-024-07113-7
Cell Physiol Biochem. 2024 Oct 20. 58(5): 597-629

Nitric Oxide-Dependent Regulation of Oxygen-Related Processes in a Rat Model of Lead Neurotoxicity: Influence of the Hypoxia Resistance Factor.

Natalia Kurhaluk, Piotr Kamiński, Oleksandr Lukash, Halina Tkaczenko.

  BACKGROUND/AIMS: Lead exposure is known to induce oxidative stress and neurotoxicity. Nitric oxide (NO) plays an important role in modulating oxidative stress, with L-arginine as a precursor of NO and Nω-nitro-L-arginine (L-NNA) as an inhibitor of NO synthase, an enzyme that catalyses the production of nitric oxide (NO) from L-arginine.METHODS: This study investigated the differential effects of L-arginine and L-NNA on markers of oxidative stress and biochemical changes in brain tissue from rats with different levels of resistance to hypoxia exposed to lead nitrate. Rats with either low or high resistance to hypoxia were exposed to lead nitrate (oral 3.6 mg lead nitrate/kg b.w. per day for 30 days) and treated with L-arginine (600 mg/kg b.w., i.p., 30 min before and after exposure to lead nitrate) or L-NNA (35 mg/kg b.w., i.p., 30 min before and after exposure to lead nitrate). Brain tissue samples were analysed for lipid peroxidation, oxidative modification of proteins, and activity of antioxidant enzymes, including superoxide dismutase, catalase, glutathione reductase, and peroxidase, and total antioxidant status (TAS). We also examined the biomarkers of biochemical pathways involving the activity of alanine and aspartate aminotransferases, succinate dehydrogenase (SDH), and α-ketoglutarate dehydrogenase (KGDH). In addition, the trend observed was supported by assessments of the acetylcholine levels and acetylcholinesterase activity (ACh-AChE system) in brain tissue.
RESULTS: In rats with low resistance to hypoxia, the L-arginine treatment significantly reduced lipid peroxidation and oxidative protein modification but increased antioxidant enzyme activity, suggesting a protective effect against lead-induced oxidative stress. Conversely, in rats with high resistance to hypoxia, L-NNA had a protective effect, reducing lead-induced oxidative damage and decreasing lipid peroxidation, whereas L-arginine exacerbated oxidative stress and impaired antioxidant defences. These findings were supported by corresponding changes in the acetylcholine-acetylcholinesterase system, reflecting the observed patterns of lead-induced oxidative stress and neurotoxicity. The study shows that L-arginine exerts a protective effect by reducing lead-induced oxidative damage via an improvement in TAS. Our study shows that lead nitrate exposure significantly increases ala-nine and aspartate aminotransferase activity in brain tissue, with L-arginine exacerbating and L-NNA reversing this effect. The lead nitrate exposure also affected the activities of SDH and KGDH, which are important for cellular energy production and hypoxia resistance, with L-arginine altering SDH activity depending on the level of resistance and L-NNA enhancing both SDH and KGDH activities. These trends were further validated by alterations in the ACh-AChE system, highlighting the differential role of NO-dependent mechanisms in modulating lead-induced neurotoxicity based on hypoxia resistance.
CONCLUSION: These findings suggest potential targeted therapeutic strategies based on the oxidative stress profile and highlight the potential of nitric oxide system modulators in counteracting lead-induced biochemical alterations and the dynamics of the ACh-AChE system depending on the individual physiological reactivity of organisms.

Keywords:  Individual physiological reactivity ; Acetylcholine-acetylcholinesterase ; Succinate dehydrogenase ; α-ketoglutarate dehydrogenase ; Oxidative modification of proteins

DOI:  https://doi.org/10.33594/000000734
Tissue Eng Part A. 2024 Oct 25.

Heterogeneity of Endothelial Cells Impacts the Functionality of Human Pancreatic In Vitro Models.

Max Urbanczyk, Athar Abuhelou, Marie Köninger, Abiramy Jeyagaran, Daniel Carvajal-Berrio, Ellie Kim, Julia Marzi, Peter Loskill, Shannon L Layland, Katja Schenke-Layland.

  Endothelial cells (ECs) play a crucial role in maintaining tissue homeostasis and functionality. Depending on their tissue of origin, ECs can be highly heterogeneous regarding their morphology, gene and protein expression, functionality, and signaling pathways. Understanding the interaction between organ-specific ECs and their surrounding tissue is therefore critical when investigating tissue homeostasis, disease development, and progression. In vitro models often lack organ-specific ECs, potentially limiting the translatability and validity of the obtained results. The goal of this study was to assess the differences between commonly used EC sources in tissue engineering applications, including human umbilical vein ECs (HUVECs), human dermal microvascular ECs (hdmvECs), and human foreskin microvascular ECs (hfmvECs), and organ-specific human pancreatic microvascular ECs (hpmvECs), and test their impact on functionality within an in vitro pancreas test system used for diabetes research. Utilizing high-resolution Raman microspectroscopy and Raman imaging in combination with established protein and gene expression analyses and exposure to defined physical signals within microfluidic cultures, we identified that ECs exhibit significant differences in their biochemical composition, relevant protein expression, angiogenic potential, and response to the application of mechanical shear stress. Proof-of-concept results showed that the coculture of isolated human islets of Langerhans with hpmvECs significantly increased the functionality when compared with control islets and islets cocultured with HUVECs. Our study demonstrates that the choice of EC type significantly impacts the experimental results, which needs to be considered when implementing ECs into in vitro models.

Keywords:  Raman imaging; Raman microspectroscopy; diabetes mellitus; endothelial cells; islets of Langerhans

DOI:  https://doi.org/10.1089/ten.tea.2024.0176
Epigenomes. 2024 Oct 22. pii: 39. [Epub ahead of print]8(4):

Epigenome Mapping in Quiescent Cells Reveals a Key Role for H3K4me3 in Regulation of RNA Polymerase II Activity.

Shengyuan Zeng, Karl Ekwall.

  (1) Background: Quiescent cells are those that have stopped dividing and show strongly reduced levels of gene expression during dormancy. In response to appropriate signals, the cells can wake up and start growing again. Many histone modifications are regulated in quiescence, but their exact functions remain to be determined. (2) Methods: Here, we map the different histone modifications, H3K4me3, H3K9ac, H3K9me2, and H3K9me3, and the histone variant H2A.Z, comparing vegetative and quiescent fission yeast (S. pombe) cells. We also map histone H3 as a control and RNA polymerase II (phosphorylated at S2 and S5) to enable comparisons of their occupancies within genes. We use ChIP-seq methodology and several different bioinformatics tools. (3) Results: The histone modification mapping data show that H3K4me3 changes stand out as being the most significant. Changes in occupancy of histone variant H2A.Z were also significant, consistent with earlier studies. Regarding gene expression changes in quiescence, we found that changes in mRNA levels were associated with changes in occupancy of RNA polymerase II (S2 and S5). Analysis of quiescence genes showed that increased H3K4me3 levels and RNA polymerase II occupancy were super-significant in a small set of core quiescence genes that are continuously upregulated during dormancy. We demonstrate that several of these genes were require Set1C/COMPASS activity for their strong induction during quiescence. (4) Conclusions: Our results imply that regulation of gene expression in quiescent cells involves epigenome changes with a key role for H3K4me3 in regulation of RNA polymerase II activity, and that different gene activation mechanisms control early and core quiescence genes. Thus, our data give further insights into important epigenome changes in quiescence using fission yeast as an experimental model.

Keywords:  G0 arrest; H3K4me3; RNA polymerase II; Set1C/COMPASS; cellular quiescence; fission yeast; histone modifications; regulation of gene expression

DOI:  https://doi.org/10.3390/epigenomes8040039
Redox Biol. 2024 Oct 19. pii: S2213-2317(24)00382-3. [Epub ahead of print]77 103404

Targeting catalase in cancer.

Christophe Glorieux, Pedro Buc Calderon.

  Healthy cells have developed a sophisticated network of antioxidant molecules to prevent the toxic accumulation of reactive oxygen species (ROS) generated by diverse environmental stresses. On the opposite, cancer cells often exhibit high levels of ROS and an altered levels of antioxidant molecules compared to normal cells. Among them, the antioxidant enzyme catalase plays an essential role in cell defense against oxidative stress through the dismutation of hydrogen peroxide into water and molecular oxygen, and its expression is often decreased in cancer cells. The elevation of ROS in cancer cells provides them proliferative advantages, and leads to metabolic reprogramming, immune escape and metastasis. In this context, catalase is of critical importance to control these cellular processes in cancer through various mechanisms. In this review, we will discuss the major progresses and challenges in understanding the role of catalase in cancer for this last decade. This review also aims to provide important updates regarding the regulation of catalase expression, subcellular localization and discuss about the potential role of microbial catalases in tumor environment. Finally, we will describe the different catalase-based therapies and address the advantages, disadvantages, and limitations associated with modulating catalase therapeutically in cancer treatment.

Keywords:  Cancer; Catalase; Catalase-based therapy; Regulation; Subcellular localization; Tumor environment

DOI:  https://doi.org/10.1016/j.redox.2024.103404
Mol Cell Endocrinol. 2024 Oct 18. pii: S0303-7207(24)00240-5. [Epub ahead of print]594 112384

High glucose elevates intracellular calcium level and induces ferroptosis in glomerular endothelial cells through the miR-223-3p/ITPR3 pathway.

Dekai Wang, Lihua Zhang, Juanli Nan, Shengbi Wan, Jingmei Luo, Xueqiong Li, Wei Chen.

  We investigated the link between ferroptosis and the miR-223-3p/inositol 1,4,5-trisphosphate receptor type 3 (ITPR3) pathway in diabetic kidney disease (DKD). Blood samples from DKD patients and healthy controls were analysed for iron ions, calcium ions, and lipid peroxidation. High-glucose-induced glomerular endothelial cells were used to simulate DKD. MiR-223-3p overexpression or silencing was achieved using adenoviruses, affecting ferroptosis regulators (glutathione peroxidase 4 [GPX4], cystine/glutamate transporter (xCT), and long-chain acyl-CoA synthetase 4 [ACSL4]) and ITPR3. DKD patients showed elevated levels of iron ions, calcium ions, and lipid peroxidation. High glucose downregulated miR-223-3p, reducing xCT and GPX4 expression and increasing ACSL4 expression. MiR-223-3p was confirmed to target ITPR3 through luciferase reporter assay. MiR-223-3p overexpression reversed high-glucose-induced effects on ferroptosis markers and ITPR3 expression. In summary, high glucose levels decreased miR-223-3p expression, leading to increased calcium ion levels and ferroptosis, potentially through ITPR3 modulation. These findings provide insights into the mechanisms underlying DKD and its potential therapeutic targets.

Keywords:  Ferroptosis; High glucose-stimulated; ITPR3; Intracellular calcium ions; miR-223-3p

DOI:  https://doi.org/10.1016/j.mce.2024.112384
Ageing Res Rev. 2024 Oct 22. pii: S1568-1637(24)00369-6. [Epub ahead of print] 102551

Roles of Hypoxia-Inducible Factor-Prolyl Hydroxylases in Aging and Disease.

Fedor Galkin, Fadi E Pulous, Yanyun Fu, Man Zhang, Frank W Pun, Feng Ren, Alex Zhavoronkov.

  The prolyl hydroxylase domain-containing (PHD or EGL9-homologs) enzyme family is mainly known for its role in the cellular response to hypoxia. HIF-PH inhibitors can stabilize hypoxia-inducible factors (HIFs), activating transcriptional programs that promote processes such as angiogenesis and erythropoiesis to adapt to changes in oxygen levels. HIF-PH inhibitors have been clinically approved for treating several types of anaemia. While most discussions of the HIF-PH signalling axis focus on hypoxia, there is a growing recognition of its importance under normoxic conditions. Recent advances in PHD biology have highlighted the potential of targeting this pathway therapeutically for a range of aging-related diseases. In this article, we review these recent discoveries, situate them within the broader context of aging and disease, and explore current therapeutic strategies that target PHD enzymes for these indications.

Keywords:  Hypoxia; Inflammageing; Inhibition; Metabolic Ageing; Prolyl Hydroxylase; Prolyl Hydroxylases

DOI:  https://doi.org/10.1016/j.arr.2024.102551
Int J Biol Sci. 2024 ;20(13): 5087-5108

HNF4A-AS1 inhibits the progression of hepatocellular carcinoma by promoting the ubiquitin-modulated degradation of PCBP2 and suppressing the stability of ARG2 mRNA.

Wenbo Jia, Liang Yu, Bin Xu, Yanzhi Feng, Jinyi Wang, Deming Zhu, Chao Xu, Litao Liang, Yongping Zhou, Lianbao Kong, Wenzhou Ding.

  Hepatocellular carcinoma (HCC) is a highly aggressive malignant tumor with a poor prognosis. Extensive research has revealed the significant role of long noncoding RNAs (lncRNAs) in the regulation of tumor development. In this study, high-throughput sequencing analysis was used to assess the expression levels of lncRNAs in three pairs of HCC tissues and their corresponding noncancerous tissues. Through quantitative real-time polymerase chain reaction (qRT-PCR) analysis and clinicopathological analysis, it was discovered that HNF4A-AS1 was downregulated in HCC tissues. Furthermore, its expression levels were found to be positively correlated with the prognosis of HCC patients. Subsequent in vitro and in vivo functional studies demonstrated that HNF4A-AS1 inhibits the proliferation, invasion, and stemness of HCC cells. Mechanistically, it was observed that HNF4A-AS1 physically interacts with the KH3 domain of PCBP2 through a specific segment (491-672 nt). This interaction facilitates the recruitment of PCBP2 by AIP4, leading to the ubiquitination and subsequent degradation of PCBP2. Furthermore, HNF4A-AS1 was found to regulate the stability of AGR2 mRNA by modulating PCBP2, thereby influencing the malignant phenotype of HCC. Overall, our study demonstrated a positive association between the decrease in HNF4A-AS1 expression and the prognosis of patients with HCC in a clinical setting. HNF4A-AS1 can suppress the stability of ARG2 mRNA by promoting the ubiquitin-modulated degradation of PCBP2, which suppresses HCC progression. HNF4A-AS1 may serve as a potential therapeutic target for HCC.

Keywords:  AGR2.; HNF4A-AS1; Hepatocellular carcinoma; PCBP2; ubiquitination

DOI:  https://doi.org/10.7150/ijbs.95276
Aging Cell. 2024 Oct 21. e14384

Vascular inflammaging: Endothelial CEACAM1 expression is upregulated by TNF-α via independent activation of NF-κB and β-catenin signaling.

Lisa Götz, Uwe Rueckschloss, Andreas Reimer, Heike Bömmel, Andreas Beilhack, Süleyman Ergün, Florian Kleefeldt.

  Chronic inflammation with progressive age, called inflammaging, contributes to the pathogenesis of cardiovascular diseases. Previously, we have shown increased vascular expression of the Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) in aged mice and humans, presumably via mutual upregulation with the pro-inflammatory cytokine TNF-α. CEACAM1 is critical for aging-associated vascular alterations like endothelial dysfunction, fibrosis, oxidative stress, and sustained inflammation and can be regarded as a main contributor to vascular inflammaging. This study was conducted to elucidate the mechanisms underlying endothelial CEACAM1 upregulation by TNF-α in detail. Using wildtype (WT) and TNF-α knockout (Tnf-/-) mice, we confirmed that the aging-related upregulation of endothelial CEACAM1 critically depends on TNF-α. The underlying mechanisms were analyzed in an endothelial cell culture model. TNF-α time-dependently upregulated CEACAM1 in vitro. In pharmacological experiments, we identified an early NF-κB- and a delayed β-catenin-mediated response. Involvement of β-catenin was further substantiated by siRNA-mediated knockdown of the β-catenin-targeted transcription factor TCF4. Both signaling pathways acted independent from each other. Elucidating the delayed response, co-immunoprecipitation analysis revealed release of β-catenin from adherens junctions by TNF-α. Finally, TNF-α activated Akt kinase by increasing its Ser473 phosphorylation. Consequently, Akt kinase facilitated β-catenin signaling by inhibiting its degradation via phosphorylation of GSK3β at Ser9 and by increased phosphorylation of β-catenin at Ser552 that augments its transcriptional activity. Taken together, our study provides novel mechanistic insights into the aging-related, inflammation-mediated endothelial upregulation of CEACAM1. Beyond the pathogenesis of cardiovascular diseases, these findings may be significant to all fields of inflammaging.

Keywords:  Aging; CEACAM1; NF‐κB; TNF‐α; endothelium; inflammation; β‐catenin

DOI:  https://doi.org/10.1111/acel.14384
Physiol Rep. 2024 Oct;12(20): e70087

Going with the flow: New insights regarding flow induced K+ secretion in the distal nephron.

Samia Lasaad, Andrew J Nickerson, Gilles Crambert, Lisa M Satlin, Thomas R Kleyman.

  K+ secretion in the distal nephron has a critical role in K+ homeostasis and is the primary route by which K+ is lost from the body. Renal K+ secretion is enhanced by increases in dietary K+ intake and by increases in tubular flow rate in the distal nephron. This review addresses new and important insights regarding the mechanisms underlying flow-induced K+ secretion (FIKS). While basal K+ secretion in the distal nephron is mediated by renal outer medullary K+ (ROMK) channels in principal cells (PCs), FIKS is mediated by large conductance, Ca2+/stretch activated K+ (BK) channels in intercalated cells (ICs), a distinct cell type. BK channel activation requires an increase in intracellular Ca2+ concentration ([Ca2+]i), and both PCs and ICs exhibit increases in [Ca2+]i in response to increases in tubular fluid flow rate, associated with an increase in tubular diameter. PIEZO1, a mechanosensitive, nonselective cation channel, is expressed in the basolateral membranes of PCs and ICs, where it functions as a mechanosensor. The loss of flow-induced [Ca2+]i transients in ICs and BK channel-mediated FIKS in microperfused collecting ducts isolated from mice with IC-specific deletion of Piezo1 in the CCD underscores the importance of PIEZO1 in the renal regulation of K+ transport.

Keywords:  BK channels; Calcium signaling; Mechanotransduction; PIEZO1; TRPV4

DOI:  https://doi.org/10.14814/phy2.70087
RSC Adv. 2024 Oct 17. 14(45): 33247-33266

Novel PPAR-γ agonists as potential neuroprotective agents against Alzheimer's disease: rational design, synthesis, in silico evaluation, PPAR-γ binding assay and transactivation and expression studies.

Priya D, Umme Hani, Nazima Haider, Sirajunisa Talath, Dhivya Shanmugarajan, Prabitha P, Archana P, B R Prashantha Kumar.

Alzheimer's disease (AD) is a neurological disorder. It is caused by accumulation of amyloid beta (Aβ) plaques and tau tangles, which gradually leads to cognitive decline and memory loss. Peroxisome proliferator-activated receptor gamma (PPAR-γ), a nuclear receptor, plays a significant role in regulating genes responsible for metabolism and inflammation. Studies have shown that PPAR-γ activation has neuroprotective effects, can potentially reduce inflammation and oxidative stress, and stimulates mitochondrial biogenesis. Current study presents the design, synthesis and in vitro evaluation of PPAR-γ agonists for AD that are tailored to optimize binding with the PPAR-γ receptor. The compounds 4a, 4h and 4j exhibited notable binding affinities towards PPAR-γ LBD, with IC50 values of 8.607, 9.242, and 5.974 μM, respectively, in TR-FRET binding assay. These compounds were cell proliferative and non-cytotoxic in a neuroblastoma cell line (SH-SY5Y). They also demonstrated dose-dependent PPAR-γ activation in transactivation assay. Their neuroprotective effect was studied based on their anti-inflammatory and anti-oxidant potential by reducing the levels of proinflammatory markers (TNF-α, IL-6 and IL-1β) and ROS in Aβ-induced SH-SY5Y neuroblastoma cells using a flow cytometry method. The synthesized compounds also showed interactions in molecular docking study with the PPAR-γ receptor and demonstrated good stability in MD simulation. Our results highlight that through activation of PPAR-γ, the compounds 4a, 4h and 4j offer neuroprotective effects by reducing neuroinflammation and oxidative stress, and hence, they may be considered lead molecules for treating AD.

DOI: https://doi.org/10.1039/d4ra06330a
Cell Signal. 2024 Oct 17. pii: S0898-6568(24)00448-0. [Epub ahead of print] 111473

Foxd3/SLC5A6 axis regulates apoptosis in LUAD cells by controlling mitochondrial biotin uptake.

Chong Zheng, Wenxuan Hu, Danni Wu, Ruiheng Chen, Chun Xu, Risheng Huang.

  Lung cancer remains one of the leading causes of cancer-related mortality worldwide, with non-small cell lung cancer (NSCLC) accounting for over 85 % of cases. Lung adenocarcinoma (LUAD) is the most common subtype of NSCLC, and while targeted therapies and immune checkpoint inhibitors have improved outcomes, many patients exhibit resistance, necessitating the development of novel treatments. This study explores the role of the SLC5A6 gene, which encodes a sodium-dependent multivitamin transporter critical for mitochondrial function, in LUAD progression. We found that SLC5A6 is significantly upregulated in LUAD tissues and is associated with poor prognosis. Overexpression of SLC5A6 enhanced cell proliferation and migration, while knockout of SLC5A6 impaired these processes and induced apoptosis by disrupting mitochondrial function. Additionally, we identified Foxd3 as a key transcription factor regulating SLC5A6 expression. In vivo experiments demonstrated that SLC5A6 knockout effectively inhibited tumor growth. These findings suggest that SLC5A6 is a potential therapeutic target for LUAD, offering a new avenue for treatment strategies.

Keywords:  Apoptosis; Biotin; Mitochondria; NSCLC; SLC5A6

DOI:  https://doi.org/10.1016/j.cellsig.2024.111473
Sci Rep. 2024 Oct 24. 14(1): 25258

Non-electrophilic NRF2 activators promote wound healing in human keratinocytes and diabetic mice and demonstrate selective downstream gene targeting.

May Barakat, Chen Han, Lin Chen, Brian P David, Junhe Shi, Angela Xu, Kornelia J Skowron, Tatum Johnson, Reginald A Woods, Aparna Ankireddy, Sekhar P Reddy, Terry W Moore, Luisa A DiPietro.

  The transcription factor NRF2 plays an important role in many biological processes and is a promising therapeutic target for many disease states. NRF2 is highly expressed in the skin and is known to play a critical role in diabetic wound healing, a serious disease process for which treatment options are limited. However, many existing NRF2 activators display off-target effects due to their electrophilic mechanism, underscoring the need for alternative approaches. In this work, we investigated two recently described non-electrophilic NRF2 activators, ADJ-310 and PRL-295, and demonstrated their efficacy in vitro and in vivo in human keratinocytes and Leprdb/db diabetic mice. We also compared the downstream targets of PRL-295 to those of the widely used electrophilic NRF2 activator CDDO-Me by RNA sequencing. Both ADJ-310 and PRL-295 maintained human keratinocyte cell viability at increasing concentrations and maintained or improved cell proliferation over time. Both compounds also increased cell migration, improving in vitro wound closure. ADJ-310 and PRL-295 enhanced the oxidative stress response in vitro, and RNA-sequencing data showed that PRL-295 activated NRF2 with a narrower transcriptomic effect than CDDO-Me. In vivo, both ADJ-310 and PRL-295 improved wound healing in Leprdb/db diabetic mice and upregulated known downstream NRF2 target genes in treated tissue. These results highlight the non-electrophilic compounds ADJ-310 and PRL-295 as effective, innovative tools for investigating the function of NRF2. These compounds directly address the need for alternative NRF2 activators and offer a new approach to studying the role of NRF2 in human disease and its potential as a therapeutic across multiple disease states.

Keywords:  Diabetic wound healing; Keratinocyte; NRF2 activation; Nuclear factor erythroid 2 related factor 2; Oxidative stress

DOI:  https://doi.org/10.1038/s41598-024-75786-3
PLoS Pathog. 2024 Oct 21. 20(10): e1012617

Mlf mediates proteotoxic response via formation of cellular foci for protein folding and degradation in Giardia.

Martina Vinopalová, Lenka Arbonová, Zoltán Füssy, Vít Dohnálek, Abdul Samad, Tomáš Bílý, Marie Vancová, Pavel Doležal.

Myeloid leukemia factor 1 (Mlf1) was identified as a proto-oncoprotein that affects hematopoietic differentiation in humans. However, its cellular function remains elusive, spanning roles from cell cycle regulation to modulation of protein aggregate formation and participation in ciliogenesis. Given that structurally conserved homologs of Mlf1 can be found across the eukaryotic tree of life, we decided to characterize its cellular role underlying this phenotypic pleiotropy. Using a model of the unicellular eukaryote Giardia intestinalis, we demonstrate that its Mlf1 homolog (GiMlf) mainly localizes to two types of cytosolic foci: microtubular structures, where it interacts with Hsp40, and ubiquitin-rich, membraneless compartments, found adjacent to mitochondrion-related organelles known as mitosomes, containing the 26S proteasome regulatory subunit 4. Upon cellular stress, GiMlf either relocates to the affected compartment or disperses across the cytoplasm, subsequently accumulating into enlarged foci during the recovery phase. In vitro assays suggest that GiMlf can be recruited to membranes through its affinity for signaling phospholipids. Importantly, cytosolic foci diminish in the gimlf knockout strain, which exhibits extensive proteomic changes indicative of compromised proteostasis. Consistent with data from other cellular systems, we propose that Mlf acts in the response to proteotoxic stress by mediating the formation of function-specific foci for protein folding and degradation.

DOI: https://doi.org/10.1371/journal.ppat.1012617
Sci Rep. 2024 10 23. 14(1): 25095

Effects of hyperglycemia on airway epithelial barrier function in WT and CF 16HBE cells.

Analia J Vazquez Cegla, Kymry T Jones, Guiying Cui, Kirsten A Cottrill, Michael Koval, Nael A McCarty.

Cystic fibrosis related diabetes (CFRD), the main co-morbidity in cystic fibrosis (CF), is associated with higher rates of lung function decline. We hypothesize that airway epithelial barrier function is impaired in CF and is further exacerbated under hyperglycemia, worsening pulmonary outcomes. Using 16HBE cells, we studied the effects of hyperglycemia in airway epithelial barrier function. Results show increased paracellular dye flux in CF cells in response to insulin under hyperglycemia. Gene expression experiments identified claudin-4 (CLDN4) as a key tight junction protein dysregulated in CF cells. CLDN4 protein localization by confocal microscopy showed that CLDN4 was tightly localized at tight junctions in WT cells, which did not change under hyperglycemia. ln contrast, CLDN4 was less well-localized in CF cells at normal glucose and localization was worsened under hyperglycemia. Treatment with highly effective modulator compounds (ETI) reversed this trend, and CFTR rescue was not affected by insulin or hyperglycemia. Bulk RNA sequencing showed differences in transcriptional responses in CF compared to WT cells under normal or high glucose, highlighting promising targets for future investigation. One of these targets is protein tyrosine phosphatase receptor type G (PTPRG), which has been previously found to play a role in defective Akt signaling and insulin resistance.

DOI: https://doi.org/10.1038/s41598-024-76526-3
J Chem Phys. 2024 Oct 28. pii: 165102. [Epub ahead of print]161(16):

Exploring the molecular pathways of the activation process in PPARγ recurrent bladder cancer mutants.

Vinícius M de Oliveira, Caique C Malospirito, Fernando B da Silva, Natália B Videira, Marieli M G Dias, Murilo N Sanches, Vitor B P Leite, Ana Carolina M Figueira.

The intricate involvement of Peroxisome Proliferator-Activated Receptor Gamma (PPARγ) in glucose homeostasis and adipogenesis is well-established. However, its role in cancer, particularly luminal bladder cancer, remains debated. The overexpression and activation of PPARγ are implicated in tumorigenesis. Specific gain-of-function mutations (M280I, I290M, and T475M) within the ligand-binding domain of PPARγ are associated with bladder cancer and receptor activation. The underlying molecular pathways prompted by these mutations remain unclear. We employed a dual-basin structure-based model (db-SBM) to explore the conformational dynamics between the inactive and active states of PPARγ and examined the effects of the M280I, I290M, and T475M mutations. Our findings, consistent with the existing literature, reveal heightened ligand-independent transcriptional activity in the I290M and T475M mutants. Both mutants showed enhanced stabilization of the active state compared to the wild-type receptor, with the I290M mutation promoting a specific transition route, making it a prime candidate for further study. Electrostatic analysis identified residues K303 and E488 as pivotal in the I290M activation cascade. Biophysical assays confirmed that disrupting the K303-E488 interaction reduced the thermal stabilization characteristic of the I290M mutation. Our study demonstrates the predictive capabilities of combining simulation and cheminformatics methods, validated by biochemical experiments, to gain insights into molecular activation mechanisms and identify target residues for protein modulation.

DOI: https://doi.org/10.1063/5.0232041