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Ahmad F, Ramamorthy S, Areeshi MY, Ashraf GM, Haque S. Isolated Mitochondrial Preparations and In organello Assays: A Powerful and Relevant Ex vivo Tool for Assessment of Brain (Patho)physiology. Curr Neuropharmacol 2023; 21:1433-1449. [PMID: 36872352 PMCID: PMC10324330 DOI: 10.2174/1570159x21666230303123555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 10/30/2022] [Accepted: 12/29/2022] [Indexed: 03/07/2023] Open
Abstract
Mitochondria regulate multiple aspects of neuronal development, physiology, plasticity, and pathology through their regulatory roles in bioenergetic, calcium, redox, and cell survival/death signalling. While several reviews have addressed these different aspects, a comprehensive discussion focussing on the relevance of isolated brain mitochondria and their utilities in neuroscience research has been lacking. This is relevant because the employment of isolated mitochondria rather than their in situ functional evaluation, offers definitive evidence of organelle-specificity, negating the interference from extra mitochondrial cellular factors/signals. This mini-review was designed primarily to explore the commonly employed in organello analytical assays for the assessment of mitochondrial physiology and its dysfunction, with a particular focus on neuroscience research. The authors briefly discuss the methodologies for biochemical isolation of mitochondria, their quality assessment, and cryopreservation. Further, the review attempts to accumulate the key biochemical protocols for in organello assessment of a multitude of mitochondrial functions critical for neurophysiology, including assays for bioenergetic activity, calcium and redox homeostasis, and mitochondrial protein translation. The purpose of this review is not to examine each and every method or study related to the functional assessment of isolated brain mitochondria, but rather to assemble the commonly used protocols of in organello mitochondrial research in a single publication. The hope is that this review will provide a suitable platform aiding neuroscientists to choose and apply the required protocols and tools to address their particular mechanistic, diagnostic, or therapeutic question dealing within the confines of the research area of mitochondrial patho-physiology in the neuronal perspective.
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Affiliation(s)
- Faraz Ahmad
- Department of Biotechnology, School of Bio Sciences and Technology (SBST), Vellore Institute of Technology, Vellore, 632014, India
| | - Siva Ramamorthy
- Department of Biotechnology, School of Bio Sciences and Technology (SBST), Vellore Institute of Technology, Vellore, 632014, India
| | - Mohammed Y. Areeshi
- Medical Laboratory Technology Department, College of Applied Medical Sciences, Jazan University, Jazan, 45142, Saudi Arabia
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, 45142, Saudi Arabia
| | - Ghulam Md. Ashraf
- Department of Medical Laboratory Sciences, College of Health Sciences, and Sharjah Institute for Medical Research, University of Sharjah, Sharjah, 27272, United Arab Emirates
| | - Shafiul Haque
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, 45142, Saudi Arabia
- Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Beirut, Lebanon
- Centre of Medical and Bio-Allied Health Sciences Research, Ajman University, Ajman, United Arab Emirates
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Bhardwaj R, Bhardwaj A, Dhawan DK, Tandon C, Kaur T. 4-PBA rescues hyperoxaluria induced nephrolithiasis by modulating urinary glycoproteins: Cross talk between endoplasmic reticulum, calcium homeostasis and mitochondria. Life Sci 2022; 305:120786. [PMID: 35809664 DOI: 10.1016/j.lfs.2022.120786] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/28/2022] [Accepted: 07/01/2022] [Indexed: 12/15/2022]
Abstract
AIM Urinary glycoproteins such as Tamm Horsfall Protein (THP) and Osteopontin (OPN) are well established key regulators of renal stone formation. Additionally, recent revelations have highlighted the influence of Endoplasmic Reticulum (ER) and mitochondria of crucial importance in nephrolithiasis. However, till date conclusive approach highlighting the influence of ER stress on urinary glycoproteins and chaperone in nephrolithiasis remains elusive. Therefore, the present study was focussed on deciphering the possible effect of 4-PBA mitigating ER stress on urinary glycoproteins and calnexin (chaperone) with emphasis on interlinking calcium homeostasis in hyperoxaluric rats. MATERIAL AND METHODS Post 9 days of treatment, animals were sacrificed, and renal tissues were investigated for urinary glycoproteins, calnexin, calcium homeostasis, ER environment, redox status, and mitochondrial linkage. KEY FINDINGS 4-PBA appreciably reversed the altered levels of THP, OPN, and calnexin observed along with curtailing the disrupted calcium homeostasis when assessed for SERCA activity and intra-cellular calcium levels. Additionally, significant improvement in the perturbed ER environment as verified by escalated ER stress markers, disturbed protein folding-aggregation-degradation (congo red assay) pathway, and redox status was found post 4-PBA intervention. Interestingly, linkage of ER stress and mitochondria was established under hyperoxaluric conditions when assessed for protein levels of VDAC1 and GRP75. SIGNIFICANCE 4-PBA treatment resulted in rectifying the repercussions of ER-mitochondrial caused distress when assessed for protein folding/aggregation/degradation events along with disturbed calcium homeostasis. The present study advocates the necessity to adopt a holistic vision towards hyperoxaluria with emphasis on glycoproteins and ER environment.
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Affiliation(s)
- Rishi Bhardwaj
- Department of Biophysics, Panjab University, Chandigarh, India
| | - Ankita Bhardwaj
- Department of Biophysics, Panjab University, Chandigarh, India
| | | | | | - Tanzeer Kaur
- Department of Biophysics, Panjab University, Chandigarh, India.
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Conti Nibali S, Di Rosa MC, Rauh O, Thiel G, Reina S, De Pinto V. Cell-free electrophysiology of human VDACs incorporated into nanodiscs: An improved method. ACTA ACUST UNITED AC 2021; 1:None. [PMID: 34568862 PMCID: PMC8448298 DOI: 10.1016/j.bpr.2021.100002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/25/2021] [Indexed: 12/15/2022]
Abstract
Voltage-dependent anion-selective channel (VDAC) is one of the main proteins of the outer mitochondrial membrane of all eukaryotes, where it forms aqueous, voltage-sensitive, and ion-selective channels. Its electrophysiological properties have been thoroughly analyzed with the planar lipid bilayer technique. To date, however, available results are based on isolations of VDACs from tissue or from recombinant VDACs produced in bacterial systems. It is well known that the cytosolic overexpression of highly hydrophobic membrane proteins often results in the formation of inclusion bodies containing insoluble aggregates. Purification of properly folded proteins and restoration of their full biological activity requires several procedures that considerably lengthen experimental times. To overcome these restraints, we propose a one-step reaction that combines in vitro cell-free protein expression with nanodisc technology to obtain human VDAC isoforms directly integrated in a native-like lipid bilayer. Reconstitution assays into artificial membranes confirm the reliability of this new methodological approach and provide results comparable to those of VDACs prepared with traditional protein isolation and reconstitution protocols. The use of membrane-mimicking nanodisc systems represents a breakthrough in VDAC electrophysiology and may be adopted to further structural studies.
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Affiliation(s)
- Stefano Conti Nibali
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Maria Carmela Di Rosa
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Oliver Rauh
- Membrane Biophysics and Center for Synthetic Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Gerhard Thiel
- Membrane Biophysics and Center for Synthetic Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Simona Reina
- Department of Biological, Geological and Environmental Sciences, Section of Molecular Biology, University of Catania, Catania, Italy.,we.MitoBiotech.srl, Catania, Italy
| | - Vito De Pinto
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy.,we.MitoBiotech.srl, Catania, Italy
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Voltage-dependent anion channel isoform 3 as a potential male contraceptive drug target. Future Med Chem 2019; 11:857-867. [PMID: 30998114 DOI: 10.4155/fmc-2018-0328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Voltage-dependent anion channel isoform 3 (VDAC3), a channel in the mitochondrial outer membrane, has been suggested to play a role in the regulation of ATP transport and Ca2+ homeostasis. These processes are regarded as important for spermatozoa motility. Accordingly, in previous years, mutations in the VDAC3-encoding gene were detected in spermatozoa with low motility from infertile patients. Therefore, it can be assumed that these mutations would cause alteration of the structure and/or charge of the VDAC3 channel. The review is focused on current knowledge about contribution of VDAC3 activity to human spermatozoa motility and morphology. We also discuss the possibility of designing new molecules that could specifically block the VDAC3 channel and consequently act as male contraceptives.
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VDAC electronics: 4. Novel electrical mechanism and thermodynamic estimations of glucose repression of yeast respiration. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:2213-2223. [DOI: 10.1016/j.bbamem.2017.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 08/06/2017] [Accepted: 09/05/2017] [Indexed: 01/19/2023]
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Wang YQ, Chang SY, Wu Q, Gou YJ, Jia L, Cui YM, Yu P, Shi ZH, Wu WS, Gao G, Chang YZ. The Protective Role of Mitochondrial Ferritin on Erastin-Induced Ferroptosis. Front Aging Neurosci 2016; 8:308. [PMID: 28066232 PMCID: PMC5167726 DOI: 10.3389/fnagi.2016.00308] [Citation(s) in RCA: 182] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 12/06/2016] [Indexed: 11/13/2022] Open
Abstract
Ferroptosis, a newly identified form of regulated cell death, is characterized by overwhelming iron-dependent accumulation of lethal lipid reactive oxygen species (ROS). Preventing cellular iron overload by reducing iron uptake and increasing iron storage may contribute to inhibit ferroptosis. Mitochondrial ferritin (FtMt) is an iron-storage protein that is located in the mitochondria, which has a significant role in modulating cellular iron metabolism. Recent studies showed that FtMt played inhibitory effects on oxidative stress-dependent neuronal cell damage. However, the potential role of FtMt in the progress of ferroptosis in neuronal cells has not been studied. To explore this, we established ferroptosis models of cell and drosophila by erastin treatment. We found that overexpression of FtMt in neuroblastoma SH-SY5Y cells significantly inhibited erastin-induced ferroptosis, which very likely was achieved by regulation of iron homeostasis. Upon erastin treatment, significant increases of cellular labile iron pool (LIP) and cytosolic ROS were observed in wild-type SH-SY5Y cells, but not in the FtMt-overexpressed cells. Consistent with that, the alterations of iron-related proteins in FtMt-overexpressed cells were different from that of the control cells. We further investigated the role of FtMt in erastin-induced ferroptosis in transgenic drosophila. We found that the wild-type drosophilas fed an erastin-containing diet didn't survive more than 3 weeks. In contrast, the FtMt overexpressing drosophilas fed the same diet were survival very well. These results indicated that FtMt played a protective role in erastin-induced ferroptosis.
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Affiliation(s)
- Yue-Qi Wang
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University Shijiazhuang, China
| | - Shi-Yang Chang
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University Shijiazhuang, China
| | - Qiong Wu
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University Shijiazhuang, China
| | - Yu-Jing Gou
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University Shijiazhuang, China
| | - Linpei Jia
- Department of Nephrology, The Second Hospital of Jilin University Changchun, China
| | - Yan-Mei Cui
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University Shijiazhuang, China
| | - Peng Yu
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University Shijiazhuang, China
| | - Zhen-Hua Shi
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University Shijiazhuang, China
| | - Wen-Shuang Wu
- Department of Clinical Laboratory, The Third Hospital of Hebei Medical University Shijiazhuang, China
| | - Guofen Gao
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University Shijiazhuang, China
| | - Yan-Zhong Chang
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University Shijiazhuang, China
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Ido Y, Yoshitomi T, Ohkura K, Yamamoto T, Shinohara Y. Utility of syntenic relationships of VDAC1 pseudogenes for not only an understanding of the phylogenetic divergence history of rodents, but also ascertaining possible pseudogene candidates as genuine pseudogenes. Genomics 2014; 104:128-33. [PMID: 24858958 DOI: 10.1016/j.ygeno.2014.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 05/06/2014] [Accepted: 05/14/2014] [Indexed: 11/20/2022]
Abstract
Rodent and human genomes were screened to identify pseudogenes of the type 1 voltage-dependent anion channel (VDAC1) in mitochondria. In addition to the 16 pseudogenes of rat VDAC1 identified in our recent study, 15 and 13 sequences were identified as pseudogenes of VDAC1 in mouse and human genome, respectively; and 4, 2, and 1 sequences, showing lower similarities with the VDAC1 sequence, were identified as "possible pseudogene candidates" in rat, mouse, and human, respectively. No syntenic combination was observed between rodent and human pseudogenes, but 2 and 1 possible pseudogene candidates of VDAC1 of rat and mouse, respectively, were found to have syntenic counterparts in mouse and rat genome, respectively; and these syntenic counterparts were genuine VDAC1 pseudogenes. Therefore, syntenic combinations of pseudogenes of VDAC1 were useful not only for a better understanding of the phylogenetic divergence history of rodents but also for ascertaining possible pseudogene candidates as genuine pseudogenes.
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Affiliation(s)
- Yusuke Ido
- Institute for Genome Research, University of Tokushima, Kuramoto-cho-3, Tokushima 770-8503, Japan; Faculty of Pharmaceutical Sciences, University of Tokushima, Shomachi-1, Tokushima 770-8505, Japan
| | - Tatsuki Yoshitomi
- Institute for Genome Research, University of Tokushima, Kuramoto-cho-3, Tokushima 770-8503, Japan; Faculty of Pharmaceutical Sciences, University of Tokushima, Shomachi-1, Tokushima 770-8505, Japan
| | - Kazuto Ohkura
- Faculty of Pharmaceutical Science, Suzuka University of Medical Science, Minamitamagaki-cho, Suzuka 513-8670, Japan
| | - Takenori Yamamoto
- Institute for Genome Research, University of Tokushima, Kuramoto-cho-3, Tokushima 770-8503, Japan; Faculty of Pharmaceutical Sciences, University of Tokushima, Shomachi-1, Tokushima 770-8505, Japan
| | - Yasuo Shinohara
- Institute for Genome Research, University of Tokushima, Kuramoto-cho-3, Tokushima 770-8503, Japan; Faculty of Pharmaceutical Sciences, University of Tokushima, Shomachi-1, Tokushima 770-8505, Japan.
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Cysteine residues impact the stability and micelle interaction dynamics of the human mitochondrial β-barrel anion channel hVDAC-2. PLoS One 2014; 9:e92183. [PMID: 24642864 PMCID: PMC3967697 DOI: 10.1371/journal.pone.0092183] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 02/20/2014] [Indexed: 01/06/2023] Open
Abstract
The anti-apoptotic 19-stranded transmembrane human voltage dependent anion channel isoform 2 (hVDAC-2) β-barrel stability is crucial for anion transport in mitochondria. The role of the unusually high number of cysteine residues in this isoform is poorly understood. Using a Cys-less construct of hVDAC-2, we haveinvestigated the contribution of cysteines to channel function, barrel stability and its influence on the strength of protein-micelle interactions. We observe that despite the overall preservation in barrel structure upon cysteine mutation, subtle local variations in the mode of interaction of the barrel with its refolded micellar environment arise, which may manifest itself in the channel activity of both the proteins.Fluorescence measurements of the Trp residues in hVDAC-2 point to possible differences in the association of the barrel with lauryldimethylamine oxide (LDAO) micelles. Upon replacement of cysteines in hVDAC-2, our data suggests greater barrel rigidity by way of intra-protein interactions. This, in turn, lowers the equilibrium barrel thermodynamic parameters in LDAOby perturbingthe stability of the protein-micelle complex. In addition to this, we also find a difference in the cooperativity of unfolding upon increasing the LDAO concentration, implying the importance of micelle concentration and micelle-protein ratios on the stability of this barrel. Our results indicate that the nine cysteine residues of hVDAC-2 are the key in establishing strong(er) barrel interactions with its environment and also impart additional malleability to the barrel scaffold.
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Huang J, Lv C, Hu M, Zhong G. The mitochondria-mediate apoptosis of Lepidopteran cells induced by azadirachtin. PLoS One 2013; 8:e58499. [PMID: 23516491 PMCID: PMC3596413 DOI: 10.1371/journal.pone.0058499] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2011] [Accepted: 02/07/2013] [Indexed: 01/31/2023] Open
Abstract
Mitochondria have been shown to play an important role in apoptosis using mammalian cell lines. However, this seems not to be the case in Drosophila, an insect model organism; thus more in-depth studies of insect cell apoptosis are necessary. In the present study, mitochondrial involvement during azadirachtin- and camptothecin-induced apoptosis in Spodoptera frugiperda Sf9 cells (isolated from Spodoptera frugiperda pupal ovarian tissue) was investigated. The results showed that both azadirachtin and camptothecin could induce apoptosis in Sf9 cells. Reactive oxygen species (ROS) generation, activation of mitochondrial permeability transition pores (MPTPs) and loss of mitochondrial membrane potential (MMP) were observed very early during apoptosis and were followed subsequently by the release of cytochrome-c from the mitochondria. Furthermore, the results also revealed that the opening of MPTPs and the loss of MMP induced by azadirachtin could be significantly inhibited by the permeability transition pore (PTP) inhibitor cyclosporin A (CsA), which was used to identify the key role of mitochondria in the apoptosis of Sf9 cells. However, in camptothecin-treated Sf9 cells, CsA could not suppress the opening of MPTPs and the loss of MMP when apoptosis was induced. The data from caspase-3 and caspase-9 activity assays and detection of apoptosis by morphological observation and flow cytometry also uncovered the different effect of CsA on the two botanical apoptosis inducers. Although different mechanisms of apoptosis induction exist, our study revealed that mitochondria play a crucial role in insect cell line apoptosis.
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Affiliation(s)
- Jingfei Huang
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, Laboratory of Insect Toxicology, South China Agricultural University, Guangzhou, P.R. China
| | - Chaojun Lv
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, Laboratory of Insect Toxicology, South China Agricultural University, Guangzhou, P.R. China
- Institute of Coconut, Chinese Academy of Tropical Agricultural Sciences, Wenchang, Hainan Province, China
| | - Meiying Hu
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, Laboratory of Insect Toxicology, South China Agricultural University, Guangzhou, P.R. China
| | - Guohua Zhong
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, Laboratory of Insect Toxicology, South China Agricultural University, Guangzhou, P.R. China
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Zheleznova NN, Yang C, Ryan RP, Halligan BD, Liang M, Greene AS, Cowley AW. Mitochondrial proteomic analysis reveals deficiencies in oxygen utilization in medullary thick ascending limb of Henle in the Dahl salt-sensitive rat. Physiol Genomics 2012; 44:829-42. [PMID: 22805345 DOI: 10.1152/physiolgenomics.00060.2012] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The renal medullary thick ascending limb (mTAL) of the Dahl salt-sensitive (SS) rat is the site of enhanced NaCl reabsorption and excess superoxide production. In the present studies we isolated mitochondria from mTAL of SS and salt-resistant control strain SS.13(BN) rats on 0.4 and 8% salt diet for 7 days and performed a proteomic analysis. Purity of mTAL and mitochondria isolations exceeded 93.6 and 55%, respectively. Using LC/MS spectral analysis techniques we identified 96 mitochondrial proteins in four biological mTAL mitochondria samples, run in duplicate, as defined by proteins with a false discovery rate <5% and scan count ≥2. Seven of these 96 proteins, including IDH2, ACADM, SCOT, Hsp60, ATPA, EFTu, and VDAC2 were differentially expressed between the two rat strains. Oxygen consumption and high-resolution respirometry analyses showed that mTAL cells and the mitochondria in the outer medulla of SS rats fed high-salt diet exhibited lower rates of oxygen utilization compared with those from SS.13(BN) rats. These studies advance the conventional proteomic paradigm of focusing exclusively upon whole tissue homogenates to a focus upon a single cell type and specific subcellular organelle. The results reveal the importance of a largely unexplored role for deficiencies of mTAL mitochondrial metabolism and oxygen utilization in salt-induced hypertension and renal medullary oxidative stress.
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Affiliation(s)
- Nadezhda N Zheleznova
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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Glutathione redox potential in the mitochondrial intermembrane space is linked to the cytosol and impacts the Mia40 redox state. EMBO J 2012; 31:3169-82. [PMID: 22705944 DOI: 10.1038/emboj.2012.165] [Citation(s) in RCA: 141] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 05/16/2012] [Indexed: 02/07/2023] Open
Abstract
Glutathione is an important mediator and regulator of cellular redox processes. Detailed knowledge of local glutathione redox potential (E(GSH)) dynamics is critical to understand the network of redox processes and their influence on cellular function. Using dynamic oxidant recovery assays together with E(GSH)-specific fluorescent reporters, we investigate the glutathione pools of the cytosol, mitochondrial matrix and intermembrane space (IMS). We demonstrate that the glutathione pools of IMS and cytosol are dynamically interconnected via porins. In contrast, no appreciable communication was observed between the glutathione pools of the IMS and matrix. By modulating redox pathways in the cytosol and IMS, we find that the cytosolic glutathione reductase system is the major determinant of E(GSH) in the IMS, thus explaining a steady-state E(GSH) in the IMS which is similar to the cytosol. Moreover, we show that the local E(GSH) contributes to the partially reduced redox state of the IMS oxidoreductase Mia40 in vivo. Taken together, we provide a comprehensive mechanistic picture of the IMS redox milieu and define the redox influences on Mia40 in living cells.
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Hu ZY, Wang J, Cheng G, Zhu XF, Huang P, Yang D, Zeng YX. Apogossypolone targets mitochondria and light enhances its anticancer activity by stimulating generation of singlet oxygen and reactive oxygen species. CHINESE JOURNAL OF CANCER 2012; 30:41-53. [PMID: 21192843 PMCID: PMC4012262 DOI: 10.5732/cjc.010.10295] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Apogossypolone (ApoG2), a novel derivative of gossypol, has been shown to be a potent inhibitor of antiapoptotic Bcl-2 family proteins and to have antitumor activity in multiple types of cancer cells. Recent reports suggest that gossypol stimulates the generation of cellular reactive oxygen species (ROS) in leukemia and colorectal carcinoma cells; however, gossypol-mediated cell death in leukemia cells was reported to be ROS-independent. This study was conducted to clarify the effect of ApoG2-induced ROS on mitochondria and cell viability, and to further evaluate its utility as a treatment for nasopharyngeal carcinoma (NPC). We tested the photocytotoxicity of ApoG2 to the poorly differentiated NPC cell line CNE-2 using the ROS-generating TL/10 illumination system. The rapid ApoG2-induced cell death was partially reversed by the antioxidant N-acetyl-L-cysteine (NAC), but the ApoG2-induced reduction of mitochondrial membrane potential (MMP) was not reversed by NAC. In the presence of TL/10 illumination, ApoG2 generated massive amounts of singlet oxygen and was more effective in inhibiting cell growth than in the absence of illumination. We also determined the influence of light on the anti-proliferative activity of ApoG2 using a CNE-2–xenograft mouse model. ApoG2 under TL/10 illumination healed tumor wounds and suppressed tumor growth more effectively than ApoG2 treatment alone. These results indicate that the ApoG2-induced CNE-2 cell death is partly ROS-dependent. ApoG2 may be used with photodynamic therapy (PDT) to treat NPC.
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Affiliation(s)
- Zhe-Yu Hu
- State Key Laboratory of Oncology in South China, Guangzhou, Guangdong 510060, PR China
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Pseudogenes of rat VDAC1: 16 gene segments in the rat genome show structural similarities with the cDNA encoding rat VDAC1, with 8 slightly expressed in certain tissues. Mamm Genome 2011; 23:286-93. [DOI: 10.1007/s00335-011-9375-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 10/15/2011] [Indexed: 11/26/2022]
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Holmuhamedov EL, Teplova VV, Johnson CB, MacDonald J. A study of the effect of ethanol on the synthesis of serine and the exchange of methyl groups in hepatocytes by NMR spectroscopy. Biophysics (Nagoya-shi) 2010. [DOI: 10.1134/s0006350910060138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Holmuhamedov EL, Czerny C, Lovelace G, Beeson CC, Baker T, Johnson CB, Pediaditakis P, Teplova VV, Tikunov A, MacDonald J, Lemasters JJ. Role of voltage-dependent anion channels of the mitochondrial outer membrane in regulation of cell metabolism. Biophysics (Nagoya-shi) 2010. [DOI: 10.1134/s0006350910050088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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VDAC, a multi-functional mitochondrial protein regulating cell life and death. Mol Aspects Med 2010; 31:227-85. [PMID: 20346371 DOI: 10.1016/j.mam.2010.03.002] [Citation(s) in RCA: 530] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Accepted: 03/17/2010] [Indexed: 01/22/2023]
Abstract
Research over the past decade has extended the prevailing view of the mitochondrion to include functions well beyond the generation of cellular energy. It is now recognized that mitochondria play a crucial role in cell signaling events, inter-organellar communication, aging, cell proliferation, diseases and cell death. Thus, mitochondria play a central role in the regulation of apoptosis (programmed cell death) and serve as the venue for cellular decisions leading to cell life or death. One of the mitochondrial proteins controlling cell life and death is the voltage-dependent anion channel (VDAC), also known as mitochondrial porin. VDAC, located in the mitochondrial outer membrane, functions as gatekeeper for the entry and exit of mitochondrial metabolites, thereby controlling cross-talk between mitochondria and the rest of the cell. VDAC is also a key player in mitochondria-mediated apoptosis. Thus, in addition to regulating the metabolic and energetic functions of mitochondria, VDAC appears to be a convergence point for a variety of cell survival and cell death signals mediated by its association with various ligands and proteins. In this article, we review what is known about the VDAC channel in terms of its structure, relevance to ATP rationing, Ca(2+) homeostasis, protection against oxidative stress, regulation of apoptosis, involvement in several diseases and its role in the action of different drugs. In light of our recent findings and the recently solved NMR- and crystallography-based 3D structures of VDAC1, the focus of this review will be on the central role of VDAC in cell life and death, addressing VDAC function in the regulation of mitochondria-mediated apoptosis with an emphasis on structure-function relations. Understanding structure-function relationships of VDAC is critical for deciphering how this channel can perform such a variety of functions, all important for cell life and death. This review also provides insight into the potential of VDAC1 as a rational target for new therapeutics.
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Ferrer I. Altered mitochondria, energy metabolism, voltage-dependent anion channel, and lipid rafts converge to exhaust neurons in Alzheimer’s disease. J Bioenerg Biomembr 2009; 41:425-31. [DOI: 10.1007/s10863-009-9243-5] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Craigen WJ, Graham BH. Genetic strategies for dissecting mammalian and Drosophila voltage-dependent anion channel functions. J Bioenerg Biomembr 2009; 40:207-12. [PMID: 18622693 DOI: 10.1007/s10863-008-9146-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Voltage-dependent anion channels (VDACs), also known as mitochondrial porins, are a family of small pore-forming proteins of the mitochondrial outer membrane that are found in all eukaryotes. VDACs are thought to play important roles in the regulated flux of metabolites between the cytosolic and mitochondrial compartments, in overall energy metabolism via interactions with cytosolic kinases, and a debated role in programmed cell death (apoptosis). The mammalian genome contains three VDAC loci termed Vdac1, Vdac2, and Vdac3, raising the question as to what function each isoform may be performing. Based upon expression studies of the mouse VDACs in yeast, biophysical differences can be identified but the physiologic significance of these differences remains unclear. Creation of "knockout" cell lines and mice that lack one or more VDAC isoforms has led to the characterization of distinct phenotypes that provide a different set of insights into function which must be interpreted in the context of complex physiologic systems. Functions in male reproduction, the central nervous system and glucose homeostasis have been identified and require a deeper and more mechanistic examination. Annotation of the genome sequence of Drosophila melanogaster has recently revealed three additional genes (CG17137, CG17139, CG17140) with homology to porin, the previously described gene that encodes the VDAC of D. melanogaster. Molecular analysis of these novel VDACs has revealed a complex pattern of gene organization and expression. Sequence comparisons with other insect VDAC homologs suggest that this gene family evolved through a mechanism of duplication and divergence from an ancestral VDAC gene during the radiation of the genus Drosophila. Striking similarities to mouse VDAC mutants can be found that emphasize the conservation of function over a long evolutionary time frame.
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Affiliation(s)
- William J Craigen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
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Lebiedzinska M, Szabadkai G, Jones AWE, Duszynski J, Wieckowski MR. Interactions between the endoplasmic reticulum, mitochondria, plasma membrane and other subcellular organelles. Int J Biochem Cell Biol 2009; 41:1805-16. [PMID: 19703651 DOI: 10.1016/j.biocel.2009.02.017] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2008] [Revised: 02/22/2009] [Accepted: 02/23/2009] [Indexed: 02/02/2023]
Abstract
Several recent works show structurally and functionally dynamic contacts between mitochondria, the plasma membrane, the endoplasmic reticulum, and other subcellular organelles. Many cellular processes require proper cooperation between the plasma membrane, the nucleus and subcellular vesicular/tubular networks such as mitochondria and the endoplasmic reticulum. It has been suggested that such contacts are crucial for the synthesis and intracellular transport of phospholipids as well as for intracellular Ca(2+) homeostasis, controlling fundamental processes like motility and contraction, secretion, cell growth, proliferation and apoptosis. Close contacts between smooth sub-domains of the endoplasmic reticulum and mitochondria have been shown to be required also for maintaining mitochondrial structure. The overall distance between the associating organelle membranes as quantified by electron microscopy is small enough to allow contact formation by proteins present on their surfaces, allowing and regulating their interactions. In this review we give a historical overview of studies on organelle interactions, and summarize the present knowledge and hypotheses concerning their regulation and (patho)physiological consequences.
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