Anti-apoptotic Role Research Articles

Expanding on roles of pleckstrin homology-like domain family A member 1 protein.

Pleckstrin homology-like domain, family A, member 1 (PHLDA1), one of the three members of PHLDA (1-3) family, has been reported to be expressed in mammalian cells and tissues and play diverse roles in various biological processes such as apoptosis, pyroptosis, and differentiation. Nevertheless, new roles and mechanisms of PHLDA1 action have come to light, with some needing further clarification. The major aim of the publication is to review proapoptotic or antiapoptotic roles of PHLDA1 in cancer, including ample evidence on PHLDA1 role as a tumor suppressor gene or oncogene and its influence on tumor progression. The role of PHLDA1 as a prognostic marker of cancer emerges, as well as its role in drug response and resistance. PHLDA1 involvement in autophagy, endoplasmic reticulum stress, pyroptosis, or differentiation is also scrutinized. It is also important to note that the association of PHLDA1 with miRNA regulation is described. Additionally, the emerging functions of PHLDA1 are indicated, specifically in inflammation and ischemia/reperfusion injury.

Nucleolar protein 3 promotes proliferation of bladder cancer cells through the PI3K-Akt pathway

Nucleolar protein 3 (NOL3), as a markedly increased protein across a range of tumors, has been well acknowledged that plays an anti-apoptotic role in malignancies, while some novel impacts of NOL3 on metastasis and chemoresistance are demonstrated recently. In this study, we uncover another role of NOL3 on promoting proliferation in bladder cancer (BLCA). The reduction of NOL3 significantly inhibited cell proliferation, and we detected the stable cell cycle arrest after knockdown of NOL3 in two-type BLCA cell lines. Mechanistically, we present the first evidence that the PI3K/Akt pathway was considerably inhibited with the decrease of NOL3 in BLCA cell lines. In addition, LY294002, a PI3K inhibitor, rescued NOL3 overexpression-mediated activation of the PI3K/Akt axis and the depression of proliferation in BLCA cell lines. In conclusion, our study suggests that NOL3 is upregulated in BLCA cells and promotes proliferation via the PI3K/Akt pathway, indicating that NOL3 may be a potential therapeutic target for BLCA.

Apoptosis and long non-coding RNAs: Focus on their roles in ischemic stroke.

Ischemic stroke (IS) is a severe and sudden cerebrovascular event, associated with notably high rates of mortality and morbidity. The process of apoptosis, a genetically orchestrated form of programmed cell death, is divided into two pathways: intrinsic and extrinsic. The intricate involvement of long non-coding RNA (lncRNA) in the pathobiology of IS, particularly in modulating neuronal apoptosis, is a burgeoning area of research. This review synthesizes the current understanding of the regulatory mechanisms of lncRNA on neuronal apoptosis in the context of ischemic stroke. Specifically, we highlight the roles of lncRNA such as ANRIL, C2dat1/2, H19, TUG1, MEG3, SNHG, and GAS5, which have been implicated in the facilitation of neuronal apoptosis. Conversely, the lncRNA N1LR has been shown to exert an inhibitory effect on this process. The role of MALAT1 in neuronal apoptosis remains a subject of ongoing debate, as its function oscillates between pro-apoptotic and anti-apoptotic roles, thus highlighting the need for further elucidation.

Molecular and structural analyses of voltage-dependent anion channel 2 and its anti-apoptotic function in stress and pollutant resistance in Pacific abalone

This study aimed to identify voltage-dependent anion channel 2 (Hdh-VDAC2) and determine its functional role in response to acute thermal stress, H2O2-induced stress, heavy metal toxicity, bacterial and viral infections, and during metamorphosis. Structural analysis confirmed that Hdh-VDAC2 is a pore-forming β-barrel protein. Molecular docking further confirmed the protein-protein interactions of Hdh-VDAC2 with Hdh-BAX, Hdh-caspase 3, and Hdh-BCL2. In the Hdh-VDAC2-inhibited hemocytes (HCY), apoptotic genes (Hdh-caspase-3 and Hdh-BAX) exhibited elevated mRNA expression, while the anti-apoptotic gene (Hdh-BCL2) was downregulated. Further, fluorescent techniques confirmed excessive reactive oxygen species (ROS) production, lower cell viability, elevated caspase 3 activity, and increased DNA fragmentation in Hdh-VDAC2-inhibited HCY, indicating an anti-apoptotic role of Hdh-VDAC2 in Pacific abalone. Transcriptomic analysis revealed differential expression patterns, with upregulation in the digestive gland (DG) and downregulation in the gill (GIL) and HCY when comparing heat-tolerant (HT) versus heat-sensitive (HS) abalone groups. Additionally, both cold and heat stresses induced Hdh-VDAC2 expression. Other environmental factors including H2O2, cadmium, bacteria, and viruses, were also shown to induce Hdh-VDAC2 mRNA expression in the GIL and DG of Pacific abalone. During metamorphosis, the blastula (BLS) stage exhibited higher Hdh-VDAC2 mRNA expression. These findings suggest that Hdh-VDAC2 plays a crucial anti-apoptotic role and may be a biomarker for summer mortality in Pacific abalone.

Effect of Voluntary Wheel Running on Anxiety- and Depression-Like Behaviors in Fluoride-Exposed Mice.

Fluoride, an environmental toxicant, could induce endoplasmic reticulum stress (ERS) in neuronal cells ultimately leading to apoptosis and emotional dysfunction. Meanwhile, voluntary wheel running contributes to mitigate anxiety and depression. Our investigation aimed to study the effect of voluntary wheel running on anxiety- and depression-like behaviors in fluoride-exposure mice. The results showed that exposure to 100 mg/L sodium fluoride (NaF) for 6 months can induce anxiety- and depression-like behavior in mice. Fluorosis mice subjected to voluntary wheel running have less anxiety- and depression-like behaviors. Nissl and TUNEL staining demonstrated that fluoride led to a reduced proportion of Nissl body area in the cerebral cortex and an increased apoptotic ratio of nerve cells in the cerebral cortex. In contrast, these pathologic damages were improved in voluntary wheel running mice exposed to NaF. Moreover, the expressions of mRNA in the cerebral cortex GABA, GAD65, GAD67, DR, vGLU, 5-HT1A, BDNF, NMDAR1, and Bcl2 were downregulated and the levels of c-fos, GRP78, PERK, eIF2α, CHOP, Caspase-12, and Caspase-3 mRNA were upregulated in mice exposed to fluoride. NaF treatment had increased the PERK, ATF6, IRE1, p-eIF2α, and Caspase-3 protein levels and reduced the expressions of proteins, including GAD67, VGAT, BDNF, NMDAR1, PSD95, and SYN. By contrast, fluorosis mice subjected to voluntary wheel running enhanced the expression of GAD65, GAD67, VGAT, and neuroplasticity-related proteins in mice and inhibited the PERK-CHOP pathway. It is worth noting that the correlation between the amount of exercise and the behavioral indicators as well as neurotransmitter levels was found. In conclusion, voluntary wheel running inhibits the fluoride-induced ERS and GRP78 expression through the PERK-CHOP pathway and plays an anti-apoptotic role, ultimately ameliorating emotional dysfunction in NaF-exposed mice.

Bcl-xL is translocated to the nucleus via CtBP2 to epigenetically promote metastasis

Nuclear Bcl-xL is found to promote cancer metastasis independently of its mitochondria-based anti-apoptotic activity. How Bcl-xL is translocated into the nucleus and how nuclear Bcl-xL regulates histone H3 trimethyl Lys4 (H3K4me3) modification have yet to be understood. Here, we report that C-terminal Binding Protein 2 (CtBP2) binds to Bcl-xL via its N-terminus and translocates Bcl-xL into the nucleus. Knockdown of CtBP2 by shRNA decreases the nuclear portion of Bcl-xL and reverses Bcl-xL-induced invasion and metastasis in mouse models. Furthermore, knockout of CtBP2 not only reduces the nuclear portion of Bcl-xL but also suppresses Bcl-xL transcription. The binding between Bcl-xL and CtBP2 is required for their interaction with MLL1, a histone H3K4 methyltransferase. Pharmacologic inhibition of the MLL1 enzymatic activity reverses Bcl-xL-induced H3K4me3 and TGFβ mRNA upregulation, as well as invasion. Moreover, the cleavage under targets and release using nuclease (CUT&RUN) assay coupled with next-generation sequencing reveals that H3K4me3 modifications are particularly enriched in the promotor regions of genes encoding TGFβ and its signaling pathway members in cancer cells overexpressing Bcl-xL. Altogether, the metastatic function of Bcl-xL is mediated by its interaction with CtBP2 and MLL1 and this study offers new therapeutic strategies to treat Bcl-xL-overexpressing cancer.

Cardioprotective role of long-term kefir and omega-3 fatty acid supplementation on myocardial apoptosis via oxidative stress-mediated lysosomal cathepsin release in isoproterenol-induced myocardial infarction rat model

Objective: The antiapoptotic and antioxidative role of long-term kefir and omega-3 fatty acids and their relationship with cysteine proteases on isoproterenol (ISO) induced myocardial infarction (MI) experimental model was investigated in our study. Material and Methods: Fifty male Sprague-Dawley rats were evenly divided into five distinct groups (n=10): Control, MI, kefir +MI, omega-3+MI, and kefir+omega 3+MI groups. Kefir 10% (with drinking water) and omega-3 fatty acid (30 mg/day per 100g body weight into the standard chow) were administrated during 30 days. ISO was subcutaneously injected into the rats (100 mg/ kg b.w.) on the 29th and 30th days. Myocardial tissue and blood samples were taken 12 hours after the last ISO dose. Creatine kinase MB (CK-MB) activities were measured in serum samples. Caspase-3, superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO), DNA fragmentation, cathepsin B and L levels, were measured in myocardial tissue. Results: Serum CK-MB (p<0.05) and cardiac tissue MDA (p>0.05), NO (p<0.01), caspase 3 (p<0.01), DNA fragmentation (p<0.001), cathepsin B (p<0.05) and L (p<0.05) activities were increased and SOD (p<0.001) activities were decreased in MI group compared to control group. The preventive effects of long-term therapy with kefir and omega-3 fatty acids have been demonstrated on apoptosis, oxidative stress markers, and cysteine protease enzymes. Conclusion: Our results showed that long-term administration of kefir and omega-3 fatty acids might be effective in reducing myocardial apoptosis through oxidative stress-mediated release of cysteine proteases in myocardial infarction, especially in the kefir and combined therapy groups.

Anti-apoptotic Role of Bcl-2-Associated Athanogene-3 Protein Overexpression in the Pathogenesis of Endometrial Cancers: An Aid for New Therapeutic Targets

Anti-apoptotic Role of Bcl-2-Associated Athanogene-3 Protein Overexpression in the Pathogenesis of Endometrial Cancers: An Aid for New Therapeutic Targets

Overexpression of NDNF Improves the Cytoprotective Effects of Aged Human Bone Marrow Mesenchymal Stem Cells by Modulating Oxidative Stress and Apoptosis.

The therapeutic potential of autologous stem cell transplantation for heart repair diminishes in the elderly due to stem cell aging. Rejuvenating aged stem cells to enhance their protective effects on injured cardiomyocytes is crucial for aging patients with heart failure. In this study, we aimed to investigate whether neuron-derived neurotrophic factor (NDNF) over-expression improves the protective effect of aged stem cells for injured cardiomyocytes and explore the underlying mechanism. Human bone marrow was collected from both young and old patients, and bone marrow mesenchymal stem cells (BMSCs) were cultured. Lentivirus expression vectors carrying NDNF genes were used to transfect aged BMSCs. Fatal hypoxia-induced injury in H9C2 cells served as an in vitro ischemia model. The conditioned medium from different BMSC groups was applied to assess the beneficial effects on hypoxia-induced damage in myocardial H9C2 cells. Results revealed that the conditioned medium of NDNF over-expressed old BMSCs increased H9C2 cell viability and reduced oxidative stress and apoptosis levels under fatal hypoxia. NDNF over-expressed old BMSCs exhibited an antiapoptotic role by upregulating the antiapoptotic gene Bcl-2 and downregulating the proapoptotic genes Bax. Additionally, the protective effects were mediated through the elevation of phosphorylated AKT. Our data support the promise of NDNF as a potential target to enhance the protective effects of autologous aged BMSCs on ischemic cardiomyocytes and then improve the curative effects of stem cell for ischemic heart injury in aged patients.

Antiapoptotic and Prometastatic Roles of Cytokine FAM3B in Triple-Negative Breast Cancer

BackgroundTriple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer. FAM3B, a secreted protein, has been extensively studied in various types of tumors. However, its function in breast cancer remains poorly understood. MethodsWe analyzed FAM3B expression data from breast cancer patients available at TCGA database and overall survival was analyzed by using the Kaplan-Meier plotter. MDA-MB-231 TNBC tumor cell line and hormone-responsive MCF-7 cell lines were transfected to overexpress FAM3B. We assessed cell death, tumorigenicity, and invasiveness in vitro through MTT analysis, flow cytometry assays, anchorage-independent tumor growth, and wound healing assays, respectively. We performed in vivo evaluation by tumor xenograft in nude mice. ResultsIn silico analysis revealed that FAM3B expression was lower in all breast tumors. However, TNBC patients with high FAM3B expression had a poor prognosis. FAM3B overexpression protected MDA-MB-231 cells from cell death, with increased expression of Bcl-2 and Bcl-xL, and reduced caspase-3 activity. MDA-MB-231 cells overexpressing FAM3B also exhibited increased tumorigenicity and migration rates in vitro, displaying increased tumor growth and reduced survival rates in xenotransplanted nude mice. This phenotype is accompanied by the upregulation of EMT-related genes Slug, Snail, TGFBR2, vimentin, N-cadherin, MMP-2, MMP-9, and MMP-14. However, these effects were not observed in the MCF-7 cells overexpressing FAM3B. ConclusionFAM3B overexpression contributes to tumor growth, promotion of metastasis, and, consequently, leads to a poor prognosis in the most aggressive forms of breast cancer. Future clinical research is necessary to validate FAM3B as both a diagnostic and a therapeutic strategy for TNBC.

PRG4 mitigates hemorrhagic shock-induced cardiac injury by inhibiting mitochondrial dysregulation, oxidative stress and NLRP3-mediated pyroptosis

Hemorrhagic shock (HS) is one of the main causes of morbidity and death in patients with trauma or major surgery. Cardiac dysfunction is a well-known complication of HS. PRG4, also known as lubricin, is a mucin-like glycoprotein that plays anti-inflammatory and anti-apoptotic roles in a variety of diseases. In this study, we aimed to explore the cardioprotective efficacy of PRG4 in HS-induced cardiac injury. Employing the HS model and RNA-seq, we found that PRG4 was increased in the myocardial tissue of rats after HS. In vivo studies suggested that HS led to abnormal hemodynamic parameters and increased cTnI levels, and PRG4 overexpression effectively reversed these changes. PRG4 also suppressed HS-induced mitochondrial disorders, as reflected by increased mitochondrial membrane potential (MMP), ATP and mitochondria cytochrome c, COXIV and TOM20, as well as decreased BNIP3L and cytoplasmic cytochrome c. Furthermore, HS led to enhanced oxidative stress, as evidenced by upregulated ROS and MDA contents, and downregulated SOD and CAT activities, and these alterations were negated by PRG4 overexpression. Notably, PRG4 repressed the NLRP3-mediated pyroptosis pathway, as illustrated by decreased NLRP3 levels, caspase-1 activity and GSDMD-NT levels. In summary, these observations indicate that PRG4 overexpression protects against HS-induced cardiac dysfunction by inhibiting mitochondrial dysregulation, oxidative stress and NLRP3-mediated pyroptosis.

Virtual screening and experimental analysis of caspase-7 inhibitors as candidates for extending the lifespan of CHO cells

BackgroundChinese hamster ovarian (CHO) cells are widely employed in biotechnology for the production of recombinant proteins. Extending the life span of CHO cells and inhibiting the loss of producing cell population through the inhibition of apoptosis can benefit the productivity of those cells. In this study, we aimed to screen and evaluate the impact of some caspase-7 inhibitor candidates on the lifespan of CHO cells. ResultsThrough virtual screening and molecular docking, risperidone was screened and selected as a potential inhibitor of caspase-7 in CHO cells. The results of MTT assay revealed that the cytotoxicity of risperidone at all concentrations was lower than 50%, and thus it can be suggested as a safe treatment for CHO cells. Annexin V apoptosis and flow cytometry assays revealed that risperidone at 1, 25, and 50 µM concentrations inhibited apoptosis 72 h post-treatment through caspase-7 inhibition. Although gene expression analysis through qRT-PCR demonstrates that risperidone did not affect caspase-7 gene expression. ConclusionsThis bioinformatics and experimental study suggests risperidone as a caspase-7 inhibitor with the potential to extend the lifespan of CHO cells and offers possible opportunities in biotechnology.How to cite: Kafi S, Najafi S, Mahnam K, et al. Virtual screening and experimental analysis of caspase-7 inhibitors as candidates for extending the lifespan of CHO cells. Electron J Biotechnol 2024;71. https://doi.org/10.1016/j.ejbt.2024.04.007.

Defining the mechanisms behind the hepatoprotective properties of curcumin.

As a critical cause of human dysfunctionality, hepatic failure leads to approximately two million deaths per year and is on the rise. Considering multiple inflammatory, oxidative, and apoptotic mechanisms behind hepatotoxicity, it urges the need for finding novel multi-targeting agents. Curcumin is a phenolic compound with anti-inflammatory, antioxidant, and anti-apoptotic roles. Curcumin possesses auspicious health benefits and protects against several diseases with exceptional safety and tolerability. This review focused on the hepatoprotective mechanisms of curcumin. The need to develop novel delivery systems of curcumin (e.g., nanoparticles, self-micro emulsifying, lipid-based colloids, solid lipid nanoparticles, cyclodextrin inclusion, phospholipid complexes, andnanoemulsions) is also considered.

Effect of estrogens on apoptosis in the pituitary of viscachas (Lagostomus maximus maximus)

Estrogens, acting through their receptors (ERα and ERβ), regulate cell turnover in the pituitary gland, influencing cell proliferation and apoptosis across various species. However, their role in pituitary processes in seasonally reproducing animals remains poorly understood. This study aims to investigate the influence of estrogens, through the expression of their specific receptors, on the apoptosis of PD cells in relation to sexual maturity, the reproductive cycle, and pregnancy in a seasonal reproductive rodent (Lagostomus maximus maximus). ERα and caspase-3-cleaved (CASP3c) immunoreactive (-ir) cells were identified through immunohistochemistry. Apoptotic cells were detected using the TUNEL technique, with quantitative analysis facilitated by image analysis software, alongside measurement of serum estradiol levels using radioimmunoassay The immunostaining pattern for ERα included nuclear (ERαn) and cytoplasmic (ERαc) staining. In male viscachas, ERα expression significantly increases from immature to adult animals, correlating with the rise in serum estradiol levels and a decrease in the percentage of apoptotic cells. During the gonadal regression period in adult males, a decrease in the number of ER-ir cells and serum levels of estradiol corresponds with an increase in the number of apoptotic cells. In females, serum levels of estradiol peaked during mid-pregnancy, coinciding with a significant decrease in the number of apoptotic cells in the PD. Simultaneously, the percentage of ERαn-ir cells reaches its maximum value during late pregnancy, indicating the need to maintain the protective action of this gonadal hormone throughout the extensive pregnancy in these rodents. Regional ERα receptor expression and apoptotic cells appear to be associated with distinct PD cell populations and their hormonal responses. Finally, elevated estradiol levels coincide with diminished apoptotic cells in the male reproductive cycle and during pregnancy, suggesting an antiapoptotic role of estradiol in this species.

Peptides Targeting the IF1-ATP Synthase Complex Modulate the Permeability Transition Pore in Cancer HeLa Cells.

The mitochondrial protein IF1 is upregulated in many tumors and acts as a pro-oncogenic protein through its interaction with the ATP synthase and the inhibition of apoptosis. We have recently characterized the molecular nature of the IF1-Oligomycin Sensitivity Conferring Protein (OSCP) subunit interaction; however, it remains to be determined whether this interaction could be targeted for novel anti-cancer therapeutic intervention. We generated mitochondria-targeting peptides to displace IF1 from the OSCP interaction. The use of one selective peptide led to displacement of the inhibitor IF1 from ATP synthase, as shown by immunoprecipitation. NMR spectroscopy analysis, aimed at clarifying whether these peptides were able to directly bind to the OSCP protein, identified a second peptide which showed affinity for the N-terminal region of this subunit overlapping the IF1 binding region. In situ treatment with the membrane-permeable derivatives of these peptides in HeLa cells, that are silenced for the IF1 inhibitor protein, showed significant inhibition in mitochondrial permeability transition and no effects on mitochondrial respiration. These peptides mimic the effects of the IF1 inhibitor protein in cancer HeLa cells and confirm that the IF1-OSCP interaction inhibits apoptosis. A third peptide was identified which counteracts the anti-apoptotic role of IF1, showing that OSCP is a promising target for anti-cancer therapies.

Abstract 465: Effect of Epstein-Barr virus lnc-BARTs on EBV genome maintenance in EBV-associated tumors

Abstract Most humans infected with Epstein-Barr virus (EBV) remain asymptomatic throughout the whole life. However, EBV is linked to several human cancers, including Burkitt's lymphoma, Hodgkin's disease, post-transplant lymphoproliferative disorder (PTLD), nasopharyngeal carcinoma (NPC), and gastric carcinoma. Among these EBV-associated tumors, EBV genome is present in 100% of NPC tumor cells. In NPC cells, EBV establishes a latent infection, expressing limited number of viral proteins but elevated levels of non-coding RNAs transcribed from the BamHI-A region of the EBV genome, also known as BamHI-A rightward transcripts (BARTs). The family of EBV BART RNAs includes BART-microRNAs (miRNAs) and long non-coding RNAs (lnc-BARTs). Although various functions of BART miRNAs have been identified, the role of EBV lnc-BARTs remains largely unknown. In this study, we provide evidence demonstrating that lnc-BARTs functions as a regulatory long non-coding RNA, referred to as lnc-BARTs. These lnc-BARTs play keys role in modulating the core networks that maintains EBV latency and promotes NPC oncogenesis through epigenetic mechanisms. Our study found that the apoptosis rate of NPC cells is significantly increased following the knockdown of EBV lnc-BARTs, indicating their anti-apoptotic role in EBV-associated tumors. Mass spectrometry analysis identified several host factors, including transcriptional regulators BRD4 and SC35’ interact with EBV lnc-BARTs in NPC cells. RNA-FISH assays showed lnc-BARTs co-localized with BRD4 and SC35 complexes in nuclear s peckles and such interaction were disrupted by JQ1, a BRD4 competitive inhibitor. Binding of lnc-BARTs to BRD4 RNA was confirmed using immunoprecipitation and pulldown assays. ATAC sequencing and transcriptome analyses showed that BART knockdown in EBV-harboring NPC cell line C666-1 led to reduced chromatin accessibility, downregulation of oncogenes, and decreased EBV episome replication and maintenance. Quantitative qPCR and DNA FISH analyses of cell samples treated with shRNA targeting lnc-BARTs or BRD4 reduced EBV copy numbers and EBNA1 RNA expression levels in EBV-infected NPC cells. Finally, ChIP sequencing analysis revealed that lnc-BARTs is critical for BRD4 binding to the oriP region of the EBV genome. These findings support a mechanism by which EBV lnc-BARTs epigenetically regulate host gene expression through functional interactions with elongation regulatory machinery and contribute to the maintenance of EBV latent genome by interaction with BRD4 complex. Citation Format: Jiayan Liu, Bobo Wing-Yee Mok, Honglin Chen. Effect of Epstein-Barr virus lnc-BARTs on EBV genome maintenance in EBV-associated tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 465.

Expression of Concern: Molecular Characterization of Severin from Clonorchis sinensis Excretory/Secretory Products and Its Potential Anti-apoptotic Role in Hepatocarcinoma PLC Cells.

Expression of Concern: Molecular Characterization of Severin from Clonorchis sinensis Excretory/Secretory Products and Its Potential Anti-apoptotic Role in Hepatocarcinoma PLC Cells.

The anti-apoptotic role of Ginkgolide B via mitochondrial permeability transition pore inhibition in retinal ischemia-reperfusion

This research delves into the effectiveness of Ginkgolide B (GB), a compound from Ginkgo biloba, in combating cell death caused by glaucoma, with a focus on mitochondrial impairment and the mitochondrial permeability transition pore (mPTP). Utilizing models of high intraocular pressure and in vitro glaucoma simulations, the study investigates GB's impact on retinal progenitor cells (RPCs) under oxygen-glucose deprivation/reperfusion (OGD/R) and in a rat glaucoma model. The study methodologies included apoptosis assessment, apoptotic marker analysis via Western blot, and mitochondrial structure and function evaluation. The findings reveal that GB notably decreases apoptosis in RPCs exposed to OGD/R in vitro, and reduces ischemia-reperfusion damage in vivo. GB's protective role is attributed to its ability to preserve mitochondrial integrity, maintain membrane potential, regulate calcium levels, and inhibit mPTP opening. These results underscore GB's potential as a therapeutic agent for acute primary angle-closure glaucoma, highlighting its capability to alleviate mitochondrial damage and apoptosis in RPCs and retinal nerve fiber layer cells.

Myogenin Regulates DUSP13 to Inhibit Apoptosis Induced by Reactive Oxygen Species.

Myogenin is well known as a crucial transcription factor in skeletal muscle development, yet its other biological functions remain unexplored. Previous research showed that myogenin suppresses apoptosis induced by angiotensin II in human induced pluripotent stem cell-derived cardiomyocytes, and offered a new perspective on myogenin's role in cardioprotection. However, the detailed mechanism of this cardioprotection, especially under oxidative stress, is still unclear. In this study, hydrogen peroxide (H2O2) was used to generate reactive oxygen species in myogenin-overexpressing cardiomyocytes. The apoptosis was examined by flow cytometry. Transcriptome sequencing (RNA-seq) was performed to identify genes regulated by myogenin. Western blotting was used to detect the protein level of DUSP13 and the phosphorylation level of p38 mitogen-activated protein kinase (MAPK). The dual-luciferase reporter assay and ChIP assay were used to confirm the binding of myogenin to the promoter region of DUSP13. DUSP13 overexpression and knockdown assays were performed to study its anti-apoptotic role. Flow cytometry analysis of apoptosis showed that overexpressing myogenin for 24 and 48 hours decreased the apoptotic ratio by 47.9% and 63.5%, respectively, compared with untreated controls. Transcriptome sequencing performed on cardiomyocytes that expressed myogenin for different amounts of time (6, 12, 24, and 48 hours) identified DUSP13 as being up-regulated by myogenin. Western blotting showed that overexpression of myogenin increased the expression of DUSP13 and decreased the phosphorylation level of p38 MAPK. A dual-luciferase reporter assay proved that myogenin bound directly to the promoter region of DUSP13 and led to strong relative luciferase activity. Direct expression of DUSP13A and DUSP13B significantly reduced the rates of apoptosis and necrosis in cells treated with H2O2. Knockdown of DUSP13B significantly increased the rate of apoptosis in cells treated with H2O2. The present findings suggest that myogenin might attenuate apoptosis induced by reactive oxygen species by up-regulating DUSP13 and inactivating the p38 MAPK pathway.

B-cell lymphoma-2 phosphorylation at Ser70 site-related autophagy mediates puerarin-inhibited the apoptosis of MC3T3-E1 cells during osteoblastogenesis.

To explore the relationship between autophagy and apoptosis regulated by puerarin during osteoblastogenesis. In this study, the effects of puerarin on the autophagic activity and apoptosis level of osteoblast precursors (MC3T3-E1 cells) was observed. Subsequently, the roles of puerarin on B-cell lymphoma-2 (Bcl-2) phosphorylation at different sites in osteoblast precursors were observed. The effect of puerarin on the interaction between Bcl-2 and autophagy regulatory molecule or pro-apoptotic molecule was also investigated using Co-immunoprecipitation assays. In addition, the effect of puerarin on mitochondrial membrane potential of osteoblast precursors was also identified by mitochondrial membrane potential fluorescence probe assays. Our results showed that puerarin can promote the autophagic activity and apoptosis level of MC3T3-E1 cells. In addition, puerarin promoted Bcl-2 phosphorylation at Ser70 site, and the dissociation of Bcl-2-Beclin1 complex. Moreover, puerarin could enhance the binding of Bcl-2-Bcl-2-Associated X (Bax) complex in MC3T3-E1 cells. Furthermore, puerarin increased the mitochondrial membrane potential of MC3T3-E1 cells. Therefore, puerarin promotes Beclin1 into autophagy flux through Bcl-2 phosphorylation at Ser70, thereby enhancing autophagy of osteoblast precursors, which mediates its anti-apoptotic role during osteoblastogenesis. Furthermore, the dissociation of Bcl-2-Beclin1 complex is conducive to the binding of Bcl-2-Bax complex, which resists the apoptosis of osteoblast precursors viathe increased mitochondrial membrane potential.