ABSTRACT
VDAC1（voltage dependent anion channel 1）is an important channel protein on the outer mitochondrial outer membrane， which regulates mitophagy， participates in the regulation of inflammatory cytokines and the activation of the inflammasome， hence being crucial to the inflammatory response. Patients with obstructive sleep apnea syndrome （OSAS） suffer neuroinflammation due to intermittent hypoxia and increased oxidative stress， leading to chronic damage and neuronal cell apoptosis， and eventually develop cognitive impairment. Since OSAS patients' cognitive impairment is significantly influenced by inflammation， and VDAC1 regulates the activation of the inflammasome， the relationship between OSAS and VDAC1， mitophagy， as well as inflammation are reviewed here. We hope that this study can provide a new breakthrough in mitophagy and inflammation in patients with cognitive dysfunction caused by OSAS.
ABSTRACT
Acetaminophen (APAP) overdose is a major cause of liver injury. Neural precursor cell expressed developmentally downregulated 4-1 (NEDD4-1) is an E3 ubiquitin ligase that has been implicated in the pathogenesis of numerous liver diseases; however, its role in APAP-induced liver injury (AILI) is unclear. Thus, this study aimed to investigate the role of NEDD4-1 in the pathogenesis of AILI. We found that NEDD4-1 was dramatically downregulated in response to APAP treatment in mouse livers and isolated mouse hepatocytes. Hepatocyte-specific NEDD4-1 knockout exacerbated APAP-induced mitochondrial damage and the resultant hepatocyte necrosis and liver injury, while hepatocyte-specific NEDD4-1 overexpression mitigated these pathological events both in vivo and in vitro. Additionally, hepatocyte NEDD4-1 deficiency led to marked accumulation of voltage-dependent anion channel 1 (VDAC1) and increased VDAC1 oligomerization. Furthermore, VDAC1 knockdown alleviated AILI and weakened the exacerbation of AILI caused by hepatocyte NEDD4-1 deficiency. Mechanistically, NEDD4-1 was found to interact with the PPTY motif of VDAC1 through its WW domain and regulate K48-linked ubiquitination and degradation of VDAC1. Our present study indicates that NEDD4-1 is a suppressor of AILI and functions by regulating the degradation of VDAC1.
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Objective:To investigate the protective effect of intermittent fasting on radiation-induced cognitive impairment and the possible underlying mechanism.Methods:A total of 36 male 7-week old c57BL/6J mice were divided into Sham-irradiation and ad libitum (Sham-AL) group, irradiation and ad libitum (IR-AL) group, and irradiation add intermittent fasting (IR-IF) group according to the random number table method, with 12 mice in each group. The cognitive function of mice was assessed by novel object recognition task. The expressions of autophagy gene 5 (ATG5), microtubulesas sociated protein light chain II (LC3II), voltage dependent anion channel protein 1 (VDAC1), interleukin-1β (IL-1β), synaptophysin (SYP), synapsin I (SYN-1), and postsynaptic density 95 (PSD95) were tested by Western blot. The location of VDAC1 in mice hippocampus was detected by immunofluorescence.Results:The discrimination index (-22.45 ± 16.76) of IR-AL group was significantly ( t=3.032, P<0.05) lower than that of Sham-AL group (30.02 ± 9.05). Compared to Sham-AL group, IR-AL group had a decreased expressions of autophagy-related proteins (ATG5 and LC3II), mitochondrial marker (VDAC1), inflammatory factors (IL-1β) as well as synapse-associated proteins SYP, SYN-1 and PSD95 ( t=2.49, 2.19, 2.40, 3.47, 2.87, 2.25, 2.17, 2.31, P<0.05). Compared to IR-AL group, IR-IF group had an increased discrimination index (21.22 ± 5.62) and the increased expressions of ATG5, LC3II, VDAC1, IL-1β, SYP, SYN-1, and PSD95 ( t=2.70, 2.88, 2.71, 3.18, 3.18, 3.11, 3.30, 3.35, 2.53, P<0.05). The immunofluorescence assay revealed that VDAC1 was co-expressed with the markers of astrocytes (GFAP) and microglia (IBA-1), but not with neurons (NEUN). Conclusions:Intermittent fasting could greatly improve the cognitive function of irradiated mice possibly by upregulating VDAC1 expression, induce autophagy, and inhibit the release of inflammatory factors and protecting the synapticplasticity in the hippocampus.
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Objective: To study the changes of mitochondria function and dynamics in colon cancer-cachexia mice and the effects of Shenqi Fuzheng Injection on these changes. Methods: A total of 40 female BLAB/c nu mice were randomly divided into control group, model group, low dose and high does of Shenqi Fuzheng Injection group, ten mice in every group. Except the control group, the mice of other groups were intraperitoneal injected with the Lovo cell line to establish the model of abdominal metastasis of colon cancer, then induced cancer cachexia. Marasmus and weight change were monitored the status of cancer cachexia in all groups. Shenqi Fuzheng Injection groups received intraperitoneal injection with 1.5 mL (2 times dose) and 3 mL (4 times dose) of drugs for every three days, seven consecutive times. After 21 days treatment, the mitochondrial related protein PGC-1, 4HNE and VDAC1 in the skeletal muscle were measured. The levels of adenosine triphosphate (ATP) and malondialdehyde (MDA) in the skeletal were detected. Results: Compared to the control group, the mice in the model group and Shenqi Fuzheng group suffered from cancer cachexia. Compared with the control group, the level of ATP in the skeletal muscle was lower in model group; The protein expression level of PGC-1 and 4HNE were remarkably increased (P 0.05); The level of MDA was significantly increased (P 0.05); The level of MDA was lower (P < 0.05). Conclusion: Shenqi Fuzheng Injection can significantly improve the status of colon cancer cachexia in mice, which may be related to the improvement of the mitochondrial function and the relieving of the mitochondrial oxidative damage.
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Aim To study the effect of puerarin( Pue) against myocardial ischemia/reperfusion injury and in-volved mitochondrial mechanism. Methods Anoxia/reoxygenation( A/R) injury model was established in H9c2 cell. Recombinant plasmid pFLAG-VDAC1 was constructed. Cells were randomly divided into 4 groups, normal control group ( Control) , A/R group, puerarin group ( Pue + A/R ) , and pFLAG-VDAC1-Pue group. Real-time PCR was used to investigate the expression of VDAC1 at mRNA level, and the expres-sion of protein level was detected by Western blot. LDH and CK activities were measured by automatic bi-ochemical analyzer. Mitochondrial membrane potential ( Δψm) and cell apoptosis were observed by flow cy-tometry method. Mitochondrial swelling test was used to detect the opening of mitochondria permeability tran- sition pore ( mPTP) . Results Compared with control group, the expression of VDAC1 and mRNA was up-regulated in A/R group, LDH and CK activity were el-evated, and then mPTP opened, Δψm collapsed, cell apoptosis was significantly increased. Puerarin pre-treatment can lower the expression of VDAC1, main-tain Δψm, prevent the opening of mPTP, and reduce apoptosis. However, the protective effect of Puerarin could be cancelled by transfection of pFLAG-VDAC1. Conclusions The cardioprotection of Puerarin against A/R injury is closely related to down-regulation of VDAC1 and prevention of mPTP opening.
ABSTRACT
Several human diseases have been associated with mitochondrial voltage-dependent anion channel-1 (VDAC1) due to its role in calcium ion transportation and apoptosis. Recent studies suggest that VDAC1 may interact with endothelium-dependent nitric oxide synthase (eNOS). Decreased VDAC1 expression may limit the physical interaction between VDAC1 and eNOS and thus impair nitric oxide production, leading to cardiovascular diseases, including pulmonary arterial hypertension (PAH). In this report, we conducted meta-analysis of genome-wide expression data to identify VDAC1 influenced genes implicated in PAH pathobiology. First, we identified the genes differentially expressed between wild-type and Vdac1 knockout mouse embryonic fibroblasts in hypoxic conditions. These genes were deemed to be influenced by VDAC1 deficiency. Gene ontology analysis indicates that the VDAC1 influenced genes are significantly associated with PAH pathobiology. Second, a molecular signature derived from the VDAC1 influenced genes was developed. We suggest that, VDAC1 has a protective role in PAH and the gene expression signature of VDAC1 influenced genes can be used to i) predict severity of pulmonary hypertension secondary to pulmonary diseases, ii) differentiate idiopathic pulmonary artery hypertension (IPAH) patients from controls, and iii) differentiate IPAH from connective tissue disease associated PAH.
Subject(s)
Animals , Humans , Mice , Hypoxia , Apoptosis , Calcium , Cardiovascular Diseases , Connective Tissue Diseases , Fibroblasts , Gene Expression , Gene Ontology , Hypertension , Hypertension, Pulmonary , Ion Transport , Lung Diseases , Mice, Knockout , Nitric Oxide , Nitric Oxide Synthase , Pulmonary Artery , TranscriptomeABSTRACT
We have previously shown that 2,4,3',5'-tetramethoxystilbene (TMS), a trans-stilbene analogue, induces apoptosis in human cancer cells. However, the detailed mechanisms of mitochondria-dependent apoptosis induced by TMS are not fully understood. In the present study, the possible roles of annexin A5 in TMS-mediated apoptosis were investigated in MCF7 human breast cancer cells. Quantitative real-time PCR analysis and Western blot analysis showed that the expression of annexin A5 was strongly increased in TMS-treated cells. TMS caused a strong translocation of annexin A5 from cytosol into mitochondria. Confocal laser scanning microscopic analysis clearly showed that TMS induced translocation of annexin A5 into mitochondria. TMS increased the expression and oligomerization of voltage-dependent anion channel (VDAC) 1, which may promote mitochondria-dependent apoptosis through disruption of mitochondrial membrane potential. When cells were treated with TMS, the levels of Bax, and Bak as well as annexin A5 were strongly enhanced. Moreover, we found that the cytosolic release of apoptogenic factors such as cytochrome c, or apoptosis-inducing factor (AIF) in mitochondria was markedly increased. Annexin A5 depletion by siRNA led to decreased proapoptotic factors such as Bax , Bak, and annexin A5. Taken together, our results indicate that annexin A5 may play an important role in TMS-mediated mitochondrial apoptosis through the regulation of proapoptotic proteins and VDAC1 expression.