Voltage-dependent anion channel(VDAC)is mainly located on the outer mitochondrial membrane. High-resolution atomic force microscopy topography shows an eye-shaped VDAC with 3.8 nm x 2.7 nm pore dimensions. New work suggests pore formation by the assembly of homo-oligomers and supramolecule of VDAC or hetero oligomers composed of VDAC and pro-apoptotic proteins, such as Bax. The oligomeric VDAC pore allows for release of cytochrome C. Thus, VDAC plays a central role in the cell life and apoptosis. It has been shown that the hexokinase (HK)-VDAC1 interaction is critical for preventing induction of apoptosis in tumor cells. VDACs are expressed more highly in cancer cells than normal cells, thus can be used as the target in chemotherapy for cancer. VDAC is also involved in pathogenesis of hematological malignancies such as myeloma and chronic lymphocytic leukemia. Following identification of sequence and structure of VDAC, studies have focused on VDAC as important pharmacological target for new anticancer therapy. To induce apoptosis, agents directly interact with VDAC or detach HK from VDAC to disrupt the anti-apoptosis activity of VDAC-HK interaction, such as methyl jasmonate (MJ) and VDAC1-based peptides. In this review, the function, modulation, structure and location of the VDAC, progress of its researches in hematological malignancies and potential as targets of anti-cancer drugs are summarized.
Hematologic Neoplasms ; metabolism ; Humans ; Voltage-Dependent Anion Channels ; chemistry ; metabolism

Mitochondrial calcium uniporter (MCU) is a conserved Ca(2+) transporter at mitochondrial in eukaryotic cells. However, the role of MCU protein in oxidative stress-induced cell death remains unclear. Here, we showed that ectopically expressed MCU is mitochondrial localized in both HeLa and primary cerebellar granule neurons (CGNs). Knockdown of endogenous MCU decreases mitochondrial Ca(2+) uptake following histamine stimulation and attenuates cell death induced by oxidative stress in both HeLa cells and CGNs. We also found MCU interacts with VDAC1 and mediates VDAC1 overexpression-induced cell death in CGNs. This finding demonstrates that MCU-VDAC1 complex regulates mitochondrial Ca(2+) uptake and oxidative stress-induced apoptosis, which might represent therapeutic targets for oxidative stress related diseases.
Animals ; Apoptosis ; Biological Transport ; Calcium ; metabolism ; Calcium Channels ; metabolism ; Cerebellum ; cytology ; HeLa Cells ; Humans ; Mice ; Mitochondria ; metabolism ; Neurons ; cytology ; metabolism ; Oxidative Stress ; Voltage-Dependent Anion Channels ; metabolism

OBJECTIVETo further study gene expression and characterization of voltage-dependent anion channels (VDACs) on human spermatozoa.

METHODSVDACs were cloned by PCR from the testis cDNA library. Recombinant human sperm VDACs were produced in E. coli system by molecular cloning technology. Sperm membrane protein was extracted by 1% Triton X-100 and separated by chloroform/methanol.

RESULTSThe gene expression of VDACs was found in the human testis cDNA library and VDAC protein was detected located on the sperm membrane by alpha-helix.

CONCLUSIONVDAC proteins, abundant on the human sperm membrane and responsible for anion transportation, play an important role in sperm signaling transduction and fertility.

Blotting, Western ; Gene Expression ; Humans ; Male ; Polymerase Chain Reaction ; Recombinant Proteins ; biosynthesis ; Signal Transduction ; physiology ; Spermatozoa ; metabolism ; Testis ; metabolism ; Voltage-Dependent Anion Channels ; biosynthesis ; physiology

OBJECTIVETo investigate the effects of different concentrations of paraquat (PQ) poisoning on the expression of voltage-dependent anion channel (VDAC) and caspase family in the mitochondria of rat lung tissue, and to explore possible mechanisms of acute lung injury induced by acute PQ poisoning.

METHODSTwo hundred healthy adult Wister rats with equal numbers of male and female ones were randomly and equally divided into control group and poisoned group. The control group received one-time gastric lavage with 1 ml of normal saline, and the poisoned group with PQ (50 mg/kg) diluted in 1 ml of normal saline. Twenty rats were collected at 1, 24, 72, 120, and 168 h after lavage with normal saline or PQ and dissected after anesthesia. Mitochondria were separated from rat lung tissue, and the content of VDAC and caspase-3, -8, and -9 were determined.

RESULTSThe expression of VDAC and caspase-3, -8, and -9 in the poisoned rats were significantly higher than that in the control group (P < 0.001). At 1, 24, 72, 120, and 168 h after exposure, acute diffuse damages were found in alveolar capillary endothelial cells, alveolar epithelial cells, and pulmonary interstitial cells. Inflammatory cell infiltration in the pulmonary interstitium, alveolar structural disorder, and substantially increased fibroblasts were also found in rat lung tissue.

CONCLUSIONPQ poisoning can up-regulate the expression of VDAC and caspase-3, -8, and -9 in mitochondria of rat lung tissue to induce acute lung injury.

Acute Lung Injury ; chemically induced ; pathology ; Animals ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Caspase 9 ; metabolism ; Caspases ; metabolism ; Female ; Lung ; drug effects ; pathology ; Male ; Mitochondria ; drug effects ; metabolism ; Paraquat ; poisoning ; Rats ; Rats, Sprague-Dawley ; Voltage-Dependent Anion Channels ; metabolism

OBJECTIVE: To investigate the changes of mitochondrion by transferring antisense oligodeoxynucleotide Stat3 into laryngeal carcinoma Hep-2 cell, for elucidating the mechanism of laryngeal carcinoma Hep-2 cell apoptosis, for developing more effective treatment for laryngeal cancer. METHOD: The designed Stat3 ASODN was transferred into laryngeal carcinoma Hep-2 cell by lipofection. Mitochondrion membrane potential, VDAC and Cyt-c were detected for determining the changes of mitochondrion. RESULT: MMP was fell, Cyt-c and VDAC were increased with the heighten concentration of ASODN. CONCLUSION Mitochondria approach play an important role in the apoptosis mechanism of human Hep-2 cell by Stat3. This research elucidated the regulating mechanism of Hep-2 cell proliferation by Stat3, provided a new research focus for clinical therapy.
Apoptosis ; Cell Proliferation ; Cytochromes c ; metabolism ; Hep G2 Cells ; Humans ; Laryngeal Neoplasms ; genetics ; metabolism ; pathology ; Membrane Potential, Mitochondrial ; Mitochondria ; metabolism ; Oligodeoxyribonucleotides, Antisense ; genetics ; STAT3 Transcription Factor ; genetics ; Transfection ; Voltage-Dependent Anion Channels ; metabolism

One group of Bcl-2 protein family, which shares only the BH3 domain (BH3-only), is critically involved in the regulation of programmed cell death. Herein we demonstrated a novel human BH3-only protein (designated as Bop) which could induce apoptosis in a BH3 domain-dependent manner. Further analysis indicated that Bop mainly localized to mitochondria and used its BH3 domain to contact the loop regions of voltage dependent anion channel 1 (VDAC1) in the outer mitochondrial membrane. In addition, purified Bop protein induced the loss of mitochondrial transmembrane potential (Δψm) and the release of cytochrome c. Furthermore, Bop used its BH3 domain to contact pro-survival Bcl-2 family members (Bcl-2, Bcl-X(L), Mcl-1, A1 and Bcl-w), which could inhibit Bop-induced apoptosis. Bop would be constrained by pro-survival Bcl-2 proteins in resting cells, because Bop became released from phosphorylated Bcl-2 induced by microtubule-interfering agent like vincristine (VCR). Indeed, knockdown experiments indicated that Bop was partially required for VCR induced cell death. Finally, Bop might need to function through Bak and Bax, likely by releasing Bak from Bcl-X(L) sequestration. In conclusion, Bop may be a novel BH3-only factor that can engage with the regulatory network of Bcl-2 family members to process intrinsic apoptotic signaling.
Amino Acid Sequence ; Animals ; Apoptosis ; Cell Line ; Cell Survival ; Humans ; Mice ; Mitochondria ; metabolism ; Mitochondrial Membranes ; metabolism ; Molecular Sequence Data ; Protein Structure, Tertiary ; Protein Transport ; Proto-Oncogene Proteins c-bcl-2 ; chemistry ; metabolism ; Signal Transduction ; Time Factors ; Voltage-Dependent Anion Channel 1 ; metabolism ; bcl-2 Homologous Antagonist-Killer Protein ; metabolism ; bcl-2-Associated X Protein ; metabolism

OBJECTIVES: Myocardial ischemia reperfusion injury (IRI) occurs occasionally in the process of ischemic heart disease. Sevoflurane preconditioning has an effect on attenuating IRI. Preserving the structural and functional integrity of mitochondria is the key to reduce myocardial IRI. Silent information regulator 3 (SIRT3), a class of nicotinamide adenine dinucleotide (NAD⁺) dependent deacetylases, is an important signal-regulating molecule in mitochondria. This study aims to explore the role of mitochondrial NAD⁺-SIRT3 pathway in attenuating myocardial IRI in rats by sevoflurane preconditioning. METHODS: A total of 60 male Sprague Dawley (SD) rats were randomly divided into 5 groups (n=12): A sham group (Sham group), an ischemia reperfusion group (IR group), a sevoflurane preconditioning group (Sev group, inhaled 2.5% sevoflurane for 30 min), a sevoflurane preconditioning+SIRT3 inhibitor 3-TYP group (Sev+3-TYP group, inhaled 2.5% sevoflurane for 30 min and received 5 mg/kg 3-TYP), and a 3-TYP group (5 mg/kg 3-TYP). Except for the Sham group, the IR model in the other 4 groups was established by ligating the left anterior descending coronary artery. The size of myocardial infarction was determined by double staining. Serum cardiac troponin I (cTnI) level was measured. The contents of NAD⁺ and ATP, the activities of mitochondrial complexes I, II, and IV, the content of MDA, the activity of SOD, and the changes of mitochondrial permeability were measured. The protein expression levels of SIRT3, SOD2, catalase (CAT), and voltage dependent anion channel 1 (VDAC1) were detected by Western blotting. The ultrastructure of myocardium was observed under transmission electron microscope. MAP and HR were recorded immediately before ischemia (T0), 30 min after ischemia (T1), 30 min after reperfusion (T2), 60 min after reperfusion (T3), and 120 min after reperfusion (T4). RESULTS: After ischemia reperfusion, the content of NAD⁺ in cardiac tissues and the expression level of SIRT3 protein were decreased (both P<0.01), and an obvious myocardial injury occurred, including the increase of myocardial infarction size and serum cTnI level (both P<0.01). Correspondingly, the mitochondria also showed obvious damage on energy metabolism, antioxidant function, and structural integrity, which was manifested as: the activities of mitochondrial complexes I, II, and IV, ATP content, protein expression levels of SOD2 and CAT were decreased, while MDA content, VDAC1 protein expression level and mitochondrial permeability were increased (all P<0.01). Compared with the IR group, the content of NAD⁺ in cardiac tissues and the expression level of SIRT3 protein were increased in the Sev group (both P<0.01); the size of myocardial infarction and the level of serum cTnI were decreased in the Sev group (both P<0.01); the activities of mitochondrial complexes I, II, and IV, ATP content, protein expression levels of SOD2 and CAT were increased, while MDA content, VDAC1 protein expression level, and mitochondrial permeability were decreased in the Sev group (all P<0.01). Compared with the Sev group, the content of NAD⁺ in cardiac tissues and the expression level of SIRT3 protein were decreased in the Sev+3-TYP group (both P<0.01); the size of myocardial infarction and the level of serum cTnI were increased in the Sev+3-TYP group (both P<0.01); the activities of mitochondrial complexes I, II, and IV, ATP content, protein expression levels of SOD2 and CAT were decreased, while MDA content, VDAC1 protein expression level, and mitochondrial permeability were increased in the Sev+3-TYP group (all P<0.01). CONCLUSIONS Sevoflurane preconditioning attenuates myocardial IRI through activating the mitochondrial NAD⁺-SIRT3 pathway to preserve the mitochondrial function.
Adenosine Triphosphate/metabolism* ; Animals ; Male ; Mitochondria/metabolism* ; Myocardial Infarction/metabolism* ; Myocardial Reperfusion Injury/metabolism* ; NAD/metabolism* ; Rats ; Rats, Sprague-Dawley ; Sevoflurane/metabolism* ; Sirtuin 3/metabolism* ; Voltage-Dependent Anion Channel 1/metabolism*

OBJECTIVETo screen and obtain the validate immunogenic membrane antigens in pancreatic cancer.

METHODSPancreatic cancer cell line SW1990 membrane protein was extracted and separated by two-dimensional gel electrophoresis (2-DE). One of the three parallel 2-DE gels underwent Coomassie blue staining while the other two underwent immunoblot. Serum IgG was purified from clinically collected sera of 66 pancreatic cancer patients and 24 chronic pancreatitis patients and used as the primary antibody of the immunoblot. Positive dots of immunoblot were identified by MALDI-TOF mass spectrometry and PMF matching. The candidate membrane antigens were further validated respectively in cell lines and tissues by RT-PCR, real-time PCR, Western blot, and their different expression level of gene and protein between pancreatic cancer cell line and normal pancreatic tissue were compared studied.

RESULTSThe immunoblot of SW1990 membrane protein with serum IgG from cancer patients showed nine positive dots which were not the same as those from immunoblot with serum IgG from chronic pancreatitis patients. One talent dot was identified with MALDI and PMF as VDAC2. RT-PCR and real-time PCR showed that the gene of VDAC2 was expressed in the pancreatic cancer cell line. Western blot showed that the expression of protein level of VDAC2 in the pancreatic cancer cell line was obviously higher than in normal pancreatic tissue.

CONCLUSIONSVDAC2 might be the candidate immunogenic membrane antigens of pancreatic cancer, and its gene is all expressed in the pancreatic cancer cell line SW1990, AsPc and P3. The protein level of VDAC2 is significantly overexpressed in pancreatic cancer cell line than in normal pancreatic tissue.

Adult ; Aged ; Antigens, Neoplasm ; isolation & purification ; Cell Line, Tumor ; Female ; Humans ; Male ; Membrane Proteins ; immunology ; isolation & purification ; Middle Aged ; Pancreatic Neoplasms ; immunology ; Proteomics ; Voltage-Dependent Anion Channel 2 ; metabolism ; Young Adult

OBJECTIVETo identify the genes involved in sperm motility.

METHODSWe hybridized asthenospermia and normal motile sperm cDNA samples with the human whole genome Affymetrix chip to screen differentially expressed genes. Then we detected the mRNA expressions of the voltage-dependent anion channel genes (VDACs) in human organs and spermatozoa by RT-PCR and compared their expressions in the poor and normal motility spermatozoa.

RESULTSDifferentially expressed genes VDACs were identified by analysis of the hybridization signals, including the 3 subtypes VDAC1, VDAC2 and VDAC3. The expression of VDAC2 mRNA was significantly decreased in the poor motility sperm (0.568 +/- 0.036), as compared with the healthy men (0.803 +/- 0.043, P < 0.01).

CONCLUSIONThe decreased expression of VDAC2 in the ejaculated spermatozoa is possibly associated with the reduction of sperm motility.

Comparative Genomic Hybridization ; Gene Expression ; Humans ; Infertility, Male ; genetics ; metabolism ; Male ; Molecular Sequence Data ; Oligonucleotide Array Sequence Analysis ; Reverse Transcriptase Polymerase Chain Reaction ; Sperm Motility ; Spermatozoa ; metabolism ; Voltage-Dependent Anion Channel 2 ; genetics

This study is to investigate the effect of recombinant hFGF-10 adenovirus on the proteome of HaCat cells, and to speculate further the possible mechanism of the effect of hFGF-10 on HaCat cells via differentially expressed proteins identified. Two-dimensional gel electrophoresis (2-DE) combined with tandem time-of-flight mass spectrometry was applied to identify the differentially expressed protein spots on the 2-DE maps of the whole-cell proteins from Ad infected and rAd-hFGF-10 infected HaCat cells. The mRNA and protein levels of the differentially expressed proteins were confirmed with semi-quantitative RT-PCR and Western blotting. The results showed that the 2-DE maps with high resolution were obtained, and four selected differentially expressed proteins involved in cell apoptosis, cytoskeleton regulation and protein degradation were identified with MALDI-TOF/TOF. The mRNA and protein levels of one of the differentially expressed proteins, VDAC2, were up-regulated in HaCat cells infected with the recombinant hFGF-10 adenovirus. The differentially expressed protein, VDAC2, may be related to the bioactivities of hFGF-10.
Adenoviridae ; genetics ; Cell Line ; Electrophoresis, Gel, Two-Dimensional ; Fibroblast Growth Factor 10 ; genetics ; metabolism ; Humans ; Keratinocytes ; cytology ; metabolism ; Proteomics ; methods ; RNA, Messenger ; metabolism ; Recombinant Proteins ; metabolism ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Transfection ; Up-Regulation ; Voltage-Dependent Anion Channel 2 ; biosynthesis ; metabolism