Voltage-dependent anion channel 1 mediates mitochondrial fission and glucose metabolic reprogramming in response to ionizing radiation.

The ionizing radiation (IR) represents a formidable challenge as an environmental factor to mitochondria, leading to disrupt cellular energy metabolism and posing health risks. Although the deleterious impacts of IR on mitochondrial function are recognized, the specific molecular targets remain incompletely elucidated. In this study, HeLa cells subjected to γ-rays exhibited concomitant oxidative stress, mitochondrial structural alterations, and diminished ATP production capacity. The γ-rays induced a dose-dependent induction of mitochondrial fission, simultaneously manifested by an elevated S616/S637 phosphorylation ratio of the dynamin-related protein 1 (DRP1) and a reduction in the expression of the mitochondrial fusion protein mitofusin 2 (MFN2). Knockdown of DRP1 effectively mitigated γ-rays-induced mitochondrial network damage, implying that DRP1 phosphorylation may act as an effector of radiation-induced mitochondrial damage. The mitochondrial outer membrane protein voltage-dependent anion channel 1 (VDAC1) was identified as a crucial player in IR-induced mitochondrial damage. The VDAC1 inhibitor 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), counteracts the excessive mitochondrial fission induced by γ-rays, consequently rebalancing the glycolytic and oxidative phosphorylation equilibrium. This metabolic shift was uncovered to enhance glycolytic capacity, thus fortifying cellular resilience and elevating the radiosensitivity of cancer cells. These findings elucidate the intricate regulatory mechanisms governing mitochondrial morphology under radiation response. It is anticipated that the development of targeted drugs directed against VDAC1 may hold promise in augmenting the sensitivity of tumor cells to radiotherapy and chemotherapy.

The role and mechanism of VDAC1 in type 2 diabetes: An underestimated target of environmental pollutants.

Type 2 diabetes (T2D) is a chronic metabolic disease that accounts for more than 90% of diabetic patients. Its main feature is hyperglycemia due to insulin resistance or insulin deficiency. With changes in diet and lifestyle habits, the incidence of T2D in adolescents has burst in recent decades. The deterioration in the exposure to the environmental pollutants further aggravates the prevalence of T2D, and consequently, it imposes a significant economic burden. Therefore, early prevention and symptomatic treatment are essential to prevent diabetic complications. Mitochondrial number and electron transport chain activity are decreased in the patients with T2D. Voltage-Dependent Anion Channel 1 (VDAC1), as a crucial channel protein on the outer membrane of mitochondria, regulates signal transduction between mitochondria and other cellular components, participating in various biological processes. When VDAC1 exists in oligomeric form, it additionally facilitates the entry and exit of macromolecules into and from mitochondria, modulating insulin secretion. We summarize and highlight the interplay between VDAC1 and T2D, especially in the environmental pollutants-related T2D, shed light on the potential therapeutic implications of targeting VDAC1 monomers and oligomers, providing a new possible target for the treatment of T2D.

Targeting VDAC: A potential therapeutic approach for mitochondrial dysfunction in Alzheimer's disease.

Mitochondrial dysfunction has been implicated in the pathogenesis of Alzheimer's disease, a neurodegenerative disorder characterized by progressive cognitive decline. Voltage-dependent anion channel (VDAC), a protein located in the outer mitochondrial membrane, plays a critical role in regulating mitochondrial function and cellular energy metabolism. Recent studies have identified VDAC as a potential therapeutic target for Alzheimer's disease. This article aims to provide an overview of the role of VDAC in mitochondrial dysfunction, its association with Alzheimer's disease, and the potential of targeting VDAC for developing novel therapeutic interventions. Understanding the involvement of VDAC in Alzheimer's disease may pave the way for the development of effective treatments that can restore mitochondrial function and halt disease progression.

Abatement of the binding of human hexokinase II enzyme monomers by in-silico method with the design of inhibitory peptides.

The hexokinase II enzyme is bound to the (VDAC1) channel in the form of a dimer and prevents the release of cell death factors from mitochondria to the cytoplasm. Studies have shown that blocking the binding of hexokinase II enzyme to (VDAC1) led to the initiation of apoptosis in cancer cells. No peptide has been designed so far to inhibit hexokinase II. The aim of this study was to inhibit the dimerization of enzyme subunits in order to inhibition the formation of (VDAC1) and the hexokinase II complex. In this study, the molecular dynamics simulation of the enzyme in monomer and dimer states was investigated in terms of RMSF, RMSD and radius of gyration. The following process involves extracting and designing variable-length peptides from the interacting segments of enzyme monomers. Using molecular dynamics simulation, the stability of the peptide was determined in terms of RMSD. Molecular docking was used to investigate the interaction between the designed peptides. Finally, the inhibitory effect of peptides on subunit association was measured using dynamic light scattering (DLS) technique. Our results showed that the designed peptides, which mimic common amino acids in dimerization, interrupt the bona fide form of the enzyme subunits. The result of this study provides a new way to disrupt the assembly process and thereby decreased the function of the hexokinase II. Supplementary Information: The online version contains supplementary material available at 10.1007/s40203-024-00201-8.

TMEM43 promotes the development of hepatocellular carcinoma by activating VDAC1 through USP7 deubiquitination.

Background: Transmembrane protein 43 (TMEM43), a member of the TMEM subfamily, is encoded by a highly conserved gene and widely expressed in most species from bacteria to humans. In previous studies, TMEM43 has been found to play an important role in a variety of tumors. However, the role of TMEM43 in cancer remains unclear. Methods: We utilized the RNA sequencing (RNA-seq) and The Cancer Genome Atlas (TGCA) databases to explore and identify genes that may play an important role in the occurrence and development of hepatocellular carcinoma (HCC), such as TMEM43. The role of TMEM43 in HCC was explored through Cell Counting Kit-8 (CCK-8) cloning, flow cytometry, and Transwell experiments. The regulatory relationship between TMEM43 and voltage-dependent anion channel 1 (VDAC1) was investigated through coimmunoprecipitation (co-IP) and western blot (WB) experiments. WB was used to study the deubiquitination effect of ubiquitin-specific protease 7 (USP7) on TMEM43. Results: In this study, we utilized the RNA-seq and TGCA databases to mine data and found that TMEM43 is highly expressed in HCC. The absence of TMEM43 in cancer cells was shown to inhibit tumor development. Further research detected an important regulatory relationship between TMEM43 and VDAC1. In addition, we found that USP7 affected the progression of HCC by regulating the ubiquitination level of TMEM43 through deubiquitination. Conclusions: Our study demonstrated that USP7 participates in the growth of HCC tumors through TMEM43/VDAC1.Our results suggest that USP7/TMEM43/VDAC1 may have predictive value and represent a new treatment strategy for HCC.

Bakuchiol targets mitochondrial proteins, prohibitins and voltage-dependent anion channels: New insights into developing antiviral agents.

We previously reported that bakuchiol, a phenolic isoprenoid anticancer compound, and its analogs exert anti-influenza activity. However, the proteins targeted by bakuchiol remain unclear. Here, we investigated the chemical structures responsible for the anti-influenza activity of bakuchiol and found that all functional groups and C6 chirality of bakuchiol were required for its anti-influenza activity. Based on these results, we synthesized a molecular probe containing a biotin tag bound to the C1 position of bakuchiol. With this probe, we performed a pulldown assay for Madin-Darby canine kidney cell lysates and purified the specific bakuchiol-binding proteins with SDS-PAGE. Using nanoLC-MS/MS analysis, we identified prohibitin (PHB) 2, voltage-dependent anion channel (VDAC) 1, and VDAC2 as binding proteins of bakuchiol. We confirmed the binding of bakuchiol to PHB1, PHB2, and VDAC2 in vitro using Western blot analysis. Immunofluorescence analysis showed that bakuchiol was bound to PHBs and VDAC2 in cells and colocalized in the mitochondria. The knockdown of PHBs or VDAC2 by transfection with specific siRNAs, along with bakuchiol cotreatment, led to significantly reduced influenza nucleoprotein expression levels and viral titers in the conditioned medium of virus-infected Madin-Darby canine kidney cells, compared to the levels observed with transfection or treatment alone. These findings indicate that reducing PHBs or VDAC2 protein, combined with bakuchiol treatment, additively suppressed the growth of influenza virus. Our findings indicate that bakuchiol exerts anti-influenza activity via a novel mechanism involving these mitochondrial proteins, providing new insight for developing anti-influenza agents.

Cypermethrin induces Sertoli cell apoptosis through endoplasmic reticulum-mitochondrial coupling involving IP3R1-GRP75-VDAC1.

A widely used type II pyrethroid pesticide cypermethrin (CYP) is one of endocrine disrupting chemicals (EDCs) with anti-androgenic activity to induce male reproductive toxicology. However, the mechanisms have not been fully elucidated. This study was to explore the effects of CYP on apoptosis of mouse Sertoli cells (TM4) and the roles of endoplasmic reticulum (ER)-mitochondria coupling involving 1,4,5-trisphosphate receptor type1-glucose-regulated protein 75-voltage-dependent anion channel 1 (IP3R1-GRP75-VDAC1). TM4 were cultured with different concentrations of CYP. Flow cytometry, calcium (Ca2+) fluorescent probe, transmission electron microscopy and confocal microscopy, and western blot were to examine apoptosis of TM4, mitochondrial Ca2+, ER-mitochondria coupling, and expressions of related proteins. CYP was found to increase apoptotic rates of TM4 significantly. CYP was shown to significantly increase expressions of cleaved caspase-3, cleaved poly ADP-ribose polymerase (PARP). Concentration of mitochondrial Ca2+ was increased by CYP treatment significantly. CYP significantly enhanced ER-mitochondria coupling. CYP was shown to increase expressions of IP3R, Grp75 and VDAC1 significantly. We suggest that CYP induces apoptosis in TM4 cells by facilitating mitochondrial Ca2+ overload regulated by ER-mitochondria coupling involving IP3R1-GRP75-VDAC1. This study identifies a novel mechanism of CYP-induced apoptosis in Sertoli cells.

Inhibitory effect of exosome-loaded KV11 on corneal neovascularization via VDAC1 and autophagy / 中华实验眼科杂志

Objective:To investigate the effects and mechanism of exosome (EXO)-loaded kringle V11 (KV11) delivery on corneal neovascularization (CNV).Methods:KV11 was bound to the surface of endothelial cell-derived exosomes by using CP05, an EXO-targeting anchoring peptide, to produce EXO-KV11.The binding efficiency and optimal concentration ratio were determined using the Apogee flow system.A total of 100 8-week-old healthy male SPF grade SD rats were selected, 10 of which were randomly selected as a normal control group without any treatment.The CNV model was established by alkali burn in the other 90 rats, which were randomly divided into three groups, EXO-KV11 group, KV11 group, and normal saline group by the random number table method, with 30 rats in each group.Each group was injected subconjunctivally with 100 μl of EXO-KV11 (25 μg), KV11 (25 μg), or normal saline every other day from the first day after the alkali burn, respectively.The CNV of rats was observed on days 1, 4, 7, and 14 after alkali burn.The CNV area was calculated by ventricular perfusion with fluorescein isothiocyanate-dextran (FITC-dextran) and corneal angiography.The amount of CNV lumen was observed by hematoxylin and eosin staining.The distribution of CD31 in rat corneas was determined by immunohistochemical method.The expression levels of voltage-dependent anion channel 1(VDAC1), endoplasmic reticulum stress, autophagy and apoptosis-associated proteins were detected by Western blot.This study was approved by the Animal Ethics Committee of Peking University People's Hospital (No.20210019). All animal procedures complied with the regulations of the Vision and Ophthalmology Association and the Animal Protection and Use Committee of Peking University.Results:The optimal concentration ratio of KV11 to EXO was 4∶1 and the binding affinity reached up to 87.5% by Apogee flow cytometers.On days 7 and 14 after alkali burn, there were significant differences in CNV area among the four groups ( F=4.613, 15.590; both at P<0.05). On day 7 after alkali burn, the CNV area was smaller in EXO-KV11 group than in KV11 and normal saline groups, with statistically significant differences (both at P<0.05). On day 14 after alkali burn, the CNV area was smaller in EXO-KV11 and KV11 groups than in normal saline group, and smaller in EXO-KV11 group than in KV11 group, showing statistically significant differences (all at P<0.05). The results of quantitative analysis of corneal fluorescence mounts showed that the relative CNV fluorescence area of the normal saline group, KV11 group and EXO-KV11 group were (8.3±1.7)%, (5.2±1.6)%and (3.4±0.7)%, respectively, showing a statistically significant overall comparison difference ( F=11.735, P<0.01). The relative CNV fluorescence area was larger in KV11 and normal saline groups than in EXO-KV11 group, and larger in normal saline group than in KV11 group, showing statistically significant differences (all at P<0.05). On day 14 after alkali burn, massive neovascular lumens were observed in the matrix of the normal saline group.The number of neovascular lumens in KV11 group was smaller than that in normal saline group.The corneal structure appeared normal in EXO-KV11 group, and neovascular lumens were rare.Numerous CD31-positive cells were observed in the corneal stroma of the normal saline group, which formed into lumen structures.The number of lumens surrounded by CD31-positive cells in the corneal stroma was smaller in KV11 group than in normal saline group, and smaller in EXO-KV11 group than in KV11 group.There were significant differences in the relative expression levels of VDAC1, protein kinase R-like endoplasmic reticulum kinase (PERK), p62, cleaved caspase 3 among the four groups ( F=35.960, 8.947, 17.791, 101.168; all at P<0.01). The relative expression levels of VDAC1, PERK, p62, cleaved caspase 3 were higher in EXO-KV11 group than in KV11 and normal saline groups, showing statistically significant differences (all at P<0.001). There was no significant difference in the relative expression of microtubule-associated proteins 1A/1B light chain 3B (LC3B)Ⅱ/LC3BⅠ protein among all four groups ( F=0.445, P=0.727). Conclusions:EXO-KV11 can inhibit CNV more remarkably than KV11.EXO-KV11 inhibits CNV by promoting the expression of VDAC1 and PERK and suppressing the autophagic flux.

Research progress in ferroptosis pathways and ubiquitination modification of ferroptosis-related molecules / 中国药理学通报

Ferroptosis is an iron-dependent cell death caused by phospholipid peroxidation damage of polyunsaturated fatty acids on cell membranes and involves several pathways, including the iron homeostasis regulatory pathway, the cystine glutamate reverse transporter (system Xc) pathway and the voltage-dependent anion channel (VDAC) pathway. Ferroptosis is involved in the development of several diseases (e. g. myocardial infarction, stroke, cancer and degenerative diseases). The ubiquitination is an important post-translational modification of various protein molecules in the organism. Studies have shown that regulating the ubiquitination of ferroptosis pathway-related molecules can control cellular ferroptosis. Targeting the ubiquitination of ferroptosis pathway-related molecules can effectively promote or inhibit ferroptosis, which is expected to be a new strategy for the treatment of cancer or cardiovascular diseases. In this paper we review the progress of the ferroptosis pathways and the ubiquitination modification of ferroptosis-related molecules.

Effects of long noncoding RNA-NRON on apoptosis following myocardial infarction in mice / 中国医科大学学报

Objective To investigate the effects of long noncoding RNA(lncRNA)-NRON on apoptosis following myocardial infarc-tion(MI)in mice.Methods The C57BL/6 mice were randomly divided into four groups:sham operation(Sham)group,MI group,MI combined with lncRNA-NRON interference lentivirus(MI+shNRON)group,and MI combined with the negative control(NC)lentivirus(MI+NC)group.The expression of lncRNA-NRON was detected using real-time PCR.In addition,the pathology of the myocardial tissue injury was analyzed using HE staining,the myocardial infarction size was examined using TTC staining,and the extent of apoptosis was assessed using the TUNEL assay,respectively.The RPISeq database was used to predict the probability of interaction between lncR-NA-NRON and the voltage-dependent anionic channel protein(VDAC).The effect of lncRNA-NRON on the expression of VDAC protein was detected using Western blotting.Results The lncRNA-NRON expression was significantly increased in the MI group,and the tar-geted knockdown of lncRNA-NRON resulted in alleviation of the pathological myocardial tissue injury,reduction in the myocardial infarc-tion area,and inhibition of apoptosis.The probability of interaction between lncRNA-NRON and VDAC reached 0.9,indicating a high probability of their association.Additionally,lncRNA-NRON could regulate the protein expression of VDAC.Conclusion Knockdown of lncRNA-NRON could reduce the occurrence of myocardial injury following myocardial infarction.This effect may be attributable to a spe-cific mechanism wherein lncRNA-NRON affects the process of apoptosis by binding to VDAC,consequently suppressing its expression.