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Wu J, Guo S, Zhang Y, Hu J, Lin W, Zhang B, Chen X, Wang H, Mo H, Zhan T. Yiqi Huoxue Decoction modifies the expression of myocardial cytoskeleton-associated proteins by regulating the AMPK signaling pathway in H9c2 cells exposed to hypoxic conditions. JOURNAL OF TRADITIONAL CHINESE MEDICAL SCIENCES 2019. [DOI: 10.1016/j.jtcms.2019.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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Bagur R, Tanguy S, Foriel S, Grichine A, Sanchez C, Pernet-Gallay K, Kaambre T, Kuznetsov AV, Usson Y, Boucher F, Guzun R. The impact of cardiac ischemia/reperfusion on the mitochondria-cytoskeleton interactions. Biochim Biophys Acta Mol Basis Dis 2016; 1862:1159-71. [PMID: 26976332 DOI: 10.1016/j.bbadis.2016.03.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Revised: 02/18/2016] [Accepted: 03/10/2016] [Indexed: 12/15/2022]
Abstract
Cardiac ischemia-reperfusion (IR) injury compromises mitochondrial oxidative phosphorylation (OxPhos) and compartmentalized intracellular energy transfer via the phosphocreatine/creatine kinase (CK) network. The restriction of ATP/ADP diffusion at the level of the mitochondrial outer membrane (MOM) is an essential element of compartmentalized energy transfer. In adult cardiomyocytes, the MOM permeability to ADP is regulated by the interaction of voltage-dependent anion channel with cytoskeletal proteins, particularly with β tubulin II. The IR-injury alters the expression and the intracellular arrangement of cytoskeletal proteins. The objective of the present study was to investigate the impact of IR on the intracellular arrangement of β tubulin II and its effect on the regulation of mitochondrial respiration. Perfused rat hearts were subjected to total ischemia (for 20min (I20) and 45min (I45)) or to ischemia followed by 30min of reperfusion (I20R and I45R groups). High resolution respirometry and fluorescent confocal microscopy were used to study respiration, β tubulin II and mitochondrial arrangements in cardiac fibers. The results of these experiments evidence a heterogeneous response of mitochondria to IR-induced damage. Moreover, the intracellular rearrangement of β tubulin II, which in the control group colocalized with mitochondria, was associated with increased apparent affinity of OxPhos for ADP, decreased regulation of respiration by creatine without altering mitochondrial CK activity and the ratio between octameric to dimeric isoenzymes. The results of this study allow us to highlight changes of mitochondrial interactions with cytoskeleton as one of the possible mechanisms underlying cardiac IR injury.
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Affiliation(s)
- Rafaela Bagur
- University Grenoble Alpes, Laboratory of Fundamental and Applied Bioenergetics, INSERM U1055, Grenoble, France; University Grenoble Alpes, TIMC-IMAG, CNRS, UMR5525, Grenoble, France
| | - Stéphane Tanguy
- University Grenoble Alpes, TIMC-IMAG, CNRS, UMR5525, Grenoble, France
| | - Sarah Foriel
- University Grenoble Alpes, Laboratory of Fundamental and Applied Bioenergetics, INSERM U1055, Grenoble, France
| | - Alexei Grichine
- University Grenoble Alpes, Life Science Imaging - In Vitro Platform, IAB, INSERM CRI U823, Grenoble, France
| | - Caroline Sanchez
- University Grenoble Alpes, TIMC-IMAG, CNRS, UMR5525, Grenoble, France
| | - Karin Pernet-Gallay
- INSERM, U836, F-38000, Grenoble, France; University Grenoble Alpes, GIN, F-38000 Grenoble, France
| | - Tuuli Kaambre
- National Institute of Chemical Physics and Biophysics, Laboratory of Bioenergetics, Tallinn, Estonia
| | - Andrey V Kuznetsov
- Innsbruck Medical University, Cardiac Surgery Research Laboratory, Innsbruck A-6020, Austria
| | - Yves Usson
- University Grenoble Alpes, TIMC-IMAG, CNRS, UMR5525, Grenoble, France
| | - François Boucher
- University Grenoble Alpes, TIMC-IMAG, CNRS, UMR5525, Grenoble, France
| | - Rita Guzun
- University Grenoble Alpes, Laboratory of Fundamental and Applied Bioenergetics, INSERM U1055, Grenoble, France; Hospital of the University Grenoble Alpes, Department Thorax (EFCR), France.
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Chen X, Zhou X, Mao TC, Shi XH, Fan DL, Zhang YM. Effect of microtubule-associated protein-4 on epidermal cell migration under different oxygen concentrations. J Dermatol 2015; 43:674-81. [PMID: 26602869 DOI: 10.1111/1346-8138.13192] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 09/25/2015] [Indexed: 11/30/2022]
Abstract
After skin trauma, regional epidermal cell migration mediates the re-epithelialization of the wound surface, which is an important step for wound healing, yet the underlying molecular regulatory mechanism is unclear. In the current study, HaCaT cells were maintained under different oxygen concentrations (1%, 21%, 40% and 65%). Technologies including immunofluorescence staining, wound scratch, transwell invasion, western blot and low-expression lentiviral vector were utilized to observe the changes in microtubule dynamics and the microtubule-associated protein (MAP)4 expression. MAP4's effect on cell migration under different oxygen concentrations was also studied. The results showed that under hyperoxic (40% and 65%) and hypoxic (1%) conditions, HaCaT cells were able to regulate cell microtubule dynamics by MAP4, thus promoting cell migration. On the other hand, MAP4 silencing through targeted shRNA attenuated HaCaT cell migration under the above oxygen concentrations. These results imply that MAP4 plays an important role in epidermal cell migration under different oxygen concentrations.
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Affiliation(s)
- Xin Chen
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Xin Zhou
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Tong-Chun Mao
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Xiao-Hua Shi
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Dong-Li Fan
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Yi-Ming Zhang
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
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WANG DEGUO, XING WEN, WANG XIN, ZHU HONGJUN. Taxol stabilizes gap junctions and reduces ischemic ventricular arrhythmias in rats in vivo. Mol Med Rep 2014; 11:3243-8. [DOI: 10.3892/mmr.2014.3137] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 11/12/2014] [Indexed: 11/05/2022] Open
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Xu X, Zhang Q, Hu JY, Zhang DX, Jiang XP, Jia JZ, Zhu JC, Huang YS. Phosphorylation of DYNLT1 at serine 82 regulates microtubule stability and mitochondrial permeabilization in hypoxia. Mol Cells 2013; 36:322-32. [PMID: 24170091 PMCID: PMC3887991 DOI: 10.1007/s10059-013-0114-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 07/09/2013] [Accepted: 08/22/2013] [Indexed: 12/19/2022] Open
Abstract
Hypoxia-induced microtubule disruption and mitochondrial permeability transition (mPT) are crucial events leading to fatal cell damage and recent studies showed that microtubules (MTs) are involved in the modulation of mitochondrial function. Dynein light chain Tctex-type 1 (DYNLT1) is thought to be associated with MTs and mitochondria. Previously we demonstrated that DYNLT1 knockdown aggravates hypoxia-induced mitochondrial permeabilization, which indicates a role of DYNLT1 in hypoxic cytoprotection. But the underlying regulatory mechanism of DYNLT1 remains illusive. Here we aimed to investigate the phosphorylation alteration of DYNLT1 at serine 82 (S82) in hypoxia (1% O2). We therefore constructed recombinant adenoviruses to generate S82E and S82A mutants, used to transfect H9c2 and HeLa cell lines. Development of hypoxia-induced mPT (MMP examining, Cyt c release and mPT pore opening assay), hypoxic energy metabolism (cellular viability and ATP quantification), and stability of MTs were examined. Our results showed that phosph-S82 (S82-P) expression was increased in early hypoxia; S82E mutation (phosphomimic) aggravated mitochondrial damage, elevated the free tubulin in cytoplasm and decreased the cellular viability; S82A mutation (dephosphomimic) seemed to diminish the hypoxia-induced injury. These data suggest that DYNLT1 phosphorylation at S82 is involved in MTs and mitochondria regulation, and their interaction and cooperation contribute to the cellular hypoxic tolerance. Thus, we provide new insights into a DYNLT1 mechanism in stabilizing MTs and mitochondria, and propose a potential therapeutic target for hypoxia cytoprotective studies.
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Affiliation(s)
- Xue Xu
- School of Nursing, The Third Military Medical University, Chongqing, China
| | - Qiong Zhang
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
| | - Jiong-yu Hu
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
| | - Dong-xia Zhang
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
| | - Xu-pin Jiang
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
| | - jie-zhi Jia
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
| | - Jing-ci Zhu
- School of Nursing, The Third Military Medical University, Chongqing, China
| | - Yue-sheng Huang
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
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Teng M, Jiang XP, Zhang Q, Zhang JP, Zhang DX, Liang GP, Huang YS. Microtubular stability affects pVHL-mediated regulation of HIF-1alpha via the p38/MAPK pathway in hypoxic cardiomyocytes. PLoS One 2012; 7:e35017. [PMID: 22506063 PMCID: PMC3323643 DOI: 10.1371/journal.pone.0035017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 03/08/2012] [Indexed: 12/04/2022] Open
Abstract
Background Our previous research found that structural changes of the microtubule network influence glycolysis in cardiomyocytes by regulating the hypoxia-inducible factor (HIF)-1α during the early stages of hypoxia. However, little is known about the underlying regulatory mechanism of the changes of HIF-1α caused by microtubule network alternation. The von Hippel-Lindau tumor suppressor protein (pVHL), as a ubiquitin ligase, is best understood as a negative regulator of HIF-1α. Methodology/Principal Findings In primary rat cardiomyocytes and H9c2 cardiac cells, microtubule-stabilization was achieved by pretreating with paclitaxel or transfection of microtubule-associated protein 4 (MAP4) overexpression plasmids and microtubule–depolymerization was achieved by pretreating with colchicine or transfection of MAP4 siRNA before hypoxia treatment. Recombinant adenovirus vectors for overexpressing pVHL or silencing of pVHL expression were constructed and transfected in primary rat cardiomyocytes and H9c2 cells. With different microtubule-stabilizing and -depolymerizing treaments, we demonstrated that the protein levels of HIF-1α were down-regulated through overexpression of pVHL and were up-regulated through knockdown of pVHL in hypoxic cardiomyocytes. Importantly, microtubular structure breakdown activated p38/MAPK pathway, accompanied with the upregulation of pVHL. In coincidence, we found that SB203580, a p38/MAPK inhibitor decreased pVHL while MKK6 (Glu) overexpression increased pVHL in the microtubule network altered-hypoxic cardiomyocytes and H9c2 cells. Conclusions/Significance This study suggests that pVHL plays an important role in the regulation of HIF-1α caused by the changes of microtubular structure and the p38/MAPK pathway participates in the process of pVHL change following microtubule network alteration in hypoxic cardiomyocytes.
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Affiliation(s)
| | | | | | | | | | | | - Yue-sheng Huang
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, The Third Military Medical University, Chongqing, China
- * E-mail:
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Fang YD, Xu X, Dang YM, Zhang YM, Zhang JP, Hu JY, Zhang Q, Dai X, Teng M, Zhang DX, Huang YS. MAP4 mechanism that stabilizes mitochondrial permeability transition in hypoxia: microtubule enhancement and DYNLT1 interaction with VDAC1. PLoS One 2011; 6:e28052. [PMID: 22164227 PMCID: PMC3229508 DOI: 10.1371/journal.pone.0028052] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2011] [Accepted: 10/31/2011] [Indexed: 01/22/2023] Open
Abstract
Mitochondrial membrane permeability has received considerable attention recently because of its key role in apoptosis and necrosis induced by physiological events such as hypoxia. The manner in which mitochondria interact with other molecules to regulate mitochondrial permeability and cell destiny remains elusive. Previously we verified that hypoxia-induced phosphorylation of microtubule-associated protein 4 (MAP4) could lead to microtubules (MTs) disruption. In this study, we established the hypoxic (1% O2) cell models of rat cardiomyocytes, H9c2 and HeLa cells to further test MAP4 function. We demonstrated that increase in the pool of MAP4 could promote the stabilization of MT networks by increasing the synthesis and polymerization of tubulin in hypoxia. Results showed MAP4 overexpression could enhance cell viability and ATP content under hypoxic conditions. Subsequently we employed a yeast two-hybrid system to tag a protein interacting with mitochondria, dynein light chain Tctex-type 1 (DYNLT1), by hVDAC1 bait. We confirmed that DYNLT1 had protein-protein interactions with voltage-dependent anion channel 1 (VDAC1) using co-immunoprecipitation; and immunofluorescence technique showed that DYNLT1 was closely associated with MTs and VDAC1. Furthermore, DYNLT1 interactions with MAP4 were explored using a knockdown technique. We thus propose two possible mechanisms triggered by MAP4: (1) stabilization of MT networks, (2) DYNLT1 modulation, which is connected with VDAC1, and inhibition of hypoxia-induced mitochondrial permeabilization.
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Affiliation(s)
- Ya-dong Fang
- State Key Laboratory for Trauma, Burn and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Xue Xu
- The No. 324 Hospital of PLA, Chongqing, China
| | - Yong-ming Dang
- State Key Laboratory for Trauma, Burn and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Yi-ming Zhang
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Jia-ping Zhang
- State Key Laboratory for Trauma, Burn and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Jiong-yu Hu
- State Key Laboratory for Trauma, Burn and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Qiong Zhang
- State Key Laboratory for Trauma, Burn and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Xia Dai
- Department of Plastic and Cosmetic Surgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Miao Teng
- State Key Laboratory for Trauma, Burn and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Dong-xia Zhang
- State Key Laboratory for Trauma, Burn and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Yue-sheng Huang
- State Key Laboratory for Trauma, Burn and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical University, Chongqing, China
- * E-mail:
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Teng M, Dang YM, Zhang JP, Zhang Q, Fang YD, Ren J, Huang YS. Microtubular stability affects cardiomyocyte glycolysis by HIF-1alpha expression and endonuclear aggregation during early stages of hypoxia. Am J Physiol Heart Circ Physiol 2010; 298:H1919-31. [PMID: 20228255 DOI: 10.1152/ajpheart.01039.2009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypoxia-inducible factor (HIF)-1alpha is a key regulator of anaerobic energy metabolism. We asked the following question: Does the breakdown of microtubular structures influence glycolysis in hypoxic cardiomyocytes by regulating HIF-1alpha? Neonatal rat cardiomyocytes were cultured under hypoxic conditions, while microtubule-stabilizing (paclitaxel) and -depolymerizing (colchicine) agents were used to change microtubular structure. Models of high microtubule-associated protein 4 (MAP4) expression and RNA interference of microtubulin expression were established. Microtubular structural changes and intracellular HIF-1alpha protein distribution were observed with laser confocal scanning microscopy. Content of key glycolytic enzymes, viability, and energy content of cardiomyocytes were determined by colorimetry and high-performance liquid chromatography. HIF-1alpha protein content and mRNA expression were determined by Western blotting and real-time PCR, respectively. Low doses of microtubule-stabilizing agent (10 mumol/l paclitaxel) and enhanced expression of MAP4 stabilized the reticular microtubular structures in hypoxic cardiomyocytes, increased the content of key glycolytic enzymes, ameliorated energy supply and enhanced cell viability, and upregulated HIF-1alpha protein expression and endonuclear aggregation. In contrast, the microtubule-depolymerizing agent (10 mumol/l colchicine) or reduced microtubulin expression had adverse affects on the same parameters, in particular, HIF-1alpha protein content and endonuclear aggregation. We conclude that microtubular structural changes influence glycolysis in the early stages of hypoxia in cardiomyocytes by regulating HIF-1alpha content. Stabilizing microtubular structures increases endonuclear and total HIF-1alpha expression, content of key glycolytic enzymes, and energy supply. These findings provide potential therapeutic targets for ameliorating cell energy metabolism during early myocardial hypoxia.
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Affiliation(s)
- Miao Teng
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical Univ., Chongqing 400038, China
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Hu JY, Chu ZG, Han J, Dang YM, Yan H, Zhang Q, Liang GP, Huang YS. The p38/MAPK pathway regulates microtubule polymerization through phosphorylation of MAP4 and Op18 in hypoxic cells. Cell Mol Life Sci 2010; 67:321-33. [PMID: 19915797 PMCID: PMC11115776 DOI: 10.1007/s00018-009-0187-z] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 10/13/2009] [Accepted: 10/16/2009] [Indexed: 02/07/2023]
Abstract
In both cardiomyocytes and HeLa cells, hypoxia (1% O(2)) quickly leads to microtubule disruption, but little is known about how microtubule dynamics change during the early stages of hypoxia. We demonstrate that microtubule associated protein 4 (MAP4) phosphorylation increases while oncoprotein 18/stathmin (Op18) phosphorylation decreases after hypoxia, but their protein levels do not change. p38/MAPK activity increases quickly after hypoxia concomitant with MAP4 phosphorylation, and the activated p38/MAPK signaling leads to MAP4 phosphorylation and to Op18 dephosphorylation, both of which induce microtubule disruption. We confirmed the interaction between phospho-p38 and MAP4 using immunoprecipitation and found that SB203580, a p38/MAPK inhibitor, increases and MKK6(Glu) overexpression decreases hypoxic cell viability. Our results demonstrate that hypoxia induces microtubule depolymerization and decreased cell viability via the activation of the p38/MAPK signaling pathway and changes the phosphorylation levels of its downstream effectors, MAP4 and Op18.
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Affiliation(s)
- Jiong-Yu Hu
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Burn Research, Southwest Hospital, The Third Military Medical University, 400038 Chongqing, People’s Republic of China
| | - Zhi-Gang Chu
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Burn Research, Southwest Hospital, The Third Military Medical University, 400038 Chongqing, People’s Republic of China
| | - Jian Han
- Department of Gynecology and Obstetrics, Daping Hospital, The Third Military Medical University, 400038 Chongqing, People’s Republic of China
| | - Yong-ming Dang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Burn Research, Southwest Hospital, The Third Military Medical University, 400038 Chongqing, People’s Republic of China
| | - Hong Yan
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Burn Research, Southwest Hospital, The Third Military Medical University, 400038 Chongqing, People’s Republic of China
| | - Qiong Zhang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Burn Research, Southwest Hospital, The Third Military Medical University, 400038 Chongqing, People’s Republic of China
| | - Guang-ping Liang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Burn Research, Southwest Hospital, The Third Military Medical University, 400038 Chongqing, People’s Republic of China
| | - Yue-Sheng Huang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Burn Research, Southwest Hospital, The Third Military Medical University, 400038 Chongqing, People’s Republic of China
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Smyth JW, Hong TT, Gao D, Vogan JM, Jensen BC, Fong TS, Simpson PC, Stainier DYR, Chi NC, Shaw RM. Limited forward trafficking of connexin 43 reduces cell-cell coupling in stressed human and mouse myocardium. J Clin Invest 2009; 120:266-79. [PMID: 20038810 DOI: 10.1172/jci39740] [Citation(s) in RCA: 195] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Accepted: 11/11/2009] [Indexed: 12/25/2022] Open
Abstract
Gap junctions form electrical conduits between adjacent myocardial cells, permitting rapid spatial passage of the excitation current essential to each heartbeat. Arrhythmogenic decreases in gap junction coupling are a characteristic of stressed, failing, and aging myocardium, but the mechanisms of decreased coupling are poorly understood. We previously found that microtubules bearing gap junction hemichannels (connexons) can deliver their cargo directly to adherens junctions. The specificity of this delivery requires the microtubule plus-end tracking protein EB1. We performed this study to investigate the hypothesis that the oxidative stress that accompanies acute and chronic ischemic disease perturbs connexon forward trafficking. We found that EB1 was displaced in ischemic human hearts, stressed mouse hearts, and isolated cells subjected to oxidative stress. As a result, we observed limited microtubule interaction with adherens junctions at intercalated discs and reduced connexon delivery and gap junction coupling. A point mutation within the tubulin-binding domain of EB1 reproduced EB1 displacement and diminished connexon delivery, confirming that EB1 displacement can limit gap junction coupling. In zebrafish hearts, oxidative stress also reduced the membrane localization of connexin and slowed the spatial spread of excitation. We anticipate that protecting the microtubule-based forward delivery apparatus of connexons could improve cell-cell coupling and reduce ischemia-related cardiac arrhythmias.
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Affiliation(s)
- James W Smyth
- Cardiovascular Research Institute, Department of Medicine, University of California-San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143, USA
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Shi FM, Yao LL, Pei BL, Zhou Q, Li XL, Li Y, Li YZ. Cortical microtubule as a sensor and target of nitric oxide signal during the defence responses to Verticillium dahliae toxins in Arabidopsis. PLANT, CELL & ENVIRONMENT 2009; 32:428-438. [PMID: 19183295 DOI: 10.1111/j.1365-3040.2009.01939.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The molecular mechanisms of signal transduction of plants in response to Verticillium dahliae (VD) are not known. Here, we show that Arabidopsis reacts to VD-toxins with a rapid burst of nitric oxide (NO) and cortical microtubule destabilization. VD-toxins treatment triggered a disruption of cortical microtubules network. This disruption can be influenced by NO production. However, cortical microtubule disruptions were not involved in regulating the NO production. The results indicated that NO may act as an upstream signalling molecule to trigger the depolymerization of cortical microtubule. Cortical microtubules may act as a target of NO signal and as a sensor to mediate the activation of PR-1 gene expression. These results suggested that NO production and cortical microtubule dynamics appeared to be parts of the important signalling system and are involved in the defence mechanisms to VD-toxins in Arabidopsis.
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Affiliation(s)
- Fu-Mei Shi
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
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Wulff T, Jessen F, Roepstorff P, Hoffmann EK. Long term anoxia in rainbow trout investigated by 2-DE and MS/MS. Proteomics 2008; 8:1009-18. [DOI: 10.1002/pmic.200700460] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Devillard L, Vandroux D, Tissier C, Dumont L, Borgeot J, Rochette L, Athias P. Involvement of microtubules in the tolerance of cardiomyocytes to cold ischemia-reperfusion. Mol Cell Biochem 2007; 307:149-57. [PMID: 17828377 DOI: 10.1007/s11010-007-9594-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Accepted: 08/23/2007] [Indexed: 11/28/2022]
Abstract
Before transplantation, the heart graft is preserved by the use of cold storage in order to limit ischemia-reperfusion stress. However, sustained exposure to low temperature may induce myocardial ultrastructural damage, particularly microtubules (MT) disruption. Previous data suggested that tubulin-binding agents are able to attenuate cold-induced cytoskeleton alterations. Thus, the aim of the present work was to study the influence of docetaxel (DX, a tubulin-binding taxane) on the effects of deep hypothermia (4 degrees C) and of simulated cold ischemia-reperfusion on the MT network and oxidative stress of cardiomyocyte (CM) in monolayer cultures prepared from newborn rat ventricles. The MT network was explored by immunocytochemistry and Western-blotting, the cell stress by tetrazolium dye assay (MTT) and lactate dehydrogenase (LDH) release, and the superoxide production by the dihydroethidium probe (DHE). The MT assembly remained stable after 4 and 8 h of hypothermia. Tubulin acetylation was promoted in CM subjected to 4-h hypothermia. Low temperature reduced the mitochondrial function and increased the basal LDH release. The cold ischemia during 4 and 8 h preserved MT network. Docetaxel promoted MT polymerization and tubulin acetylation in basal and in cold conditions. This drug decreased the release of LDH induced by cold ischemia. Moreover, hypothermia (4 h) significantly raised the anion superoxide production. Docetaxel decreased this oxidative stress in the control CM and in CM submitted to 4 h of hypothermia. These data demonstrated that stabilizing MT with DX exerted a protective effect on CM subjected to hypothermia and to cold ischemia-reperfusion. Tubulin-ligands should be thus considered to improve the tolerance of the heart graft toward stressing conservative conditions.
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Affiliation(s)
- Lisa Devillard
- Laboratory of Experimental Cardiovascular Physiopathology and Pharmacology, IFR Santé-STIC, Institute of Cardiovascular Research, University Hospital Center, 21079, Dijon Cedex, France
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14
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Devillard L, Vandroux D, Tissier C, Brochot A, Voisin S, Rochette L, Athias P. Tubulin ligands suggest a microtubule–NADPH oxidase relationship in postischemic cardiomyocytes. Eur J Pharmacol 2006; 548:64-73. [PMID: 16973157 DOI: 10.1016/j.ejphar.2006.08.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Revised: 07/21/2006] [Accepted: 08/02/2006] [Indexed: 11/29/2022]
Abstract
Alterations of the microtubule network, which is involved in many vital processes, occur in several pathological conditions, such as cardiac ischemia. However, the connection between the microtubule assembly state and the factors affecting myocardial reperfusion injury, especially oxidative stress, is unknown. We aimed thus to study the effects of different tubulin ligands on the changes in the microtubule network and in several markers of cell injury and oxidative activity in cardiac muscle cells submitted to a reversible substrate-free, hypoxia-reoxygenation model of ischemia-reperfusion. The microtubule network was visualized by immunocytochemistry. Cell injury was evaluated via lactate dehydrogenase release and the mitochondrial function by the MTT test. Superoxide production was detected using dihydroethidium. The activity of NADPH oxidase and mRNA subunit expression were investigated. The microtubule disassembly induced by simulated ischemia was reversed by placing cardiomyocytes under normoxic conditions. This post-"ischemic" restoration of microtubule assembly was modulated by microtubule stabilizers (taxol: paclitaxel) and by microtubule disrupting drugs (nocodazole, colchicine). In addition, nocodazole decreased superoxide anion production as well as NADPH oxidase activity and mRNA expression of the NADPH oxidase subunit p22phox. These results demonstrated that the "ischemia"-induced microtubule network alteration is reversible and suggest a possible relationship between "reperfusion"-induced reassembly of microtubules and free radical generation in post-"ischemic" cardiomyocytes.
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Affiliation(s)
- Lisa Devillard
- Laboratory of Experimental Cardiovascular Physiopathology and Pharmacology, Institute of Cardiovascular Research, University Hospital Center, 21079 Dijon, France
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Athias P, Vandroux D, Tissier C, Rochette L. [Development of cardiac physiopathological models from cultured cardiomyocytes]. Ann Cardiol Angeiol (Paris) 2006; 55:90-9. [PMID: 16708992 DOI: 10.1016/j.ancard.2006.02.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The cultures of neonatal rat cardiomyocytes represent a very useful tool for the observation and the understanding of the cellular aspects of the electrophysiological, contractile, morphological, metabolic and molecular properties of the myocardium. This model is characterized by a homogeneous population of cardiac muscular cells and by vast possibilities of control of the chemical and physical environment of the cells, allowing the in vitro mimicry of a wide range of cardiac pathological situations. The cardiomyocyte cultures are thus suited to very varied experimental protocols, allowing multiparametric analysis of the cardiocellular effects of different stress such as hypoxia-reoxygenation, of ischemia-reperfusion, of the free radical attack and of thermal shock. These investigations can be combined with the study of the effects and of the cytotoxicity of pharmacological agents, not limited to the putatively cardioactive drugs. The present review proposes an outline of the procedures for the isolation, the culture and the use of neonatal cardiomyocytes. To illustrate the potentialities of this preparation, we describe more specifically the protocols and the various consequences at the cellular scale of an in vitro model of myocardial ischemia reperfusion.
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Affiliation(s)
- P Athias
- Laboratoire de physiopathologie et pharmacologie cardiovasculaires expérimentales (LPPCE), IFR no 100, institut de recherche cardiovasculaire, CHU le Bocage, 2, boulevard Maréchal-de-Lattre-de-Tassigny, BP 77908, 21079 Dijon, France.
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16
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Abstract
Small heat shock proteins (sHSPs) function as molecular chaperones, preventing stress induced aggregation of partially denatured proteins and promoting their return to native conformations when favorable conditions pertain. Sequence similarity between sHSPs resides predominately in an internal stretch of residues termed the alpha-crystallin domain, a region usually flanked by two extensions. The poorly conserved N-terminal extension influences oligomer construction and chaperone activity, whereas the flexible C-terminal extension stabilizes quaternary structure and enhances protein/substrate complex solubility. sHSP polypeptides assemble into dynamic oligomers which undergo subunit exchange and they bind a wide range of cellular substrates. As molecular chaperones, the sHSPs protect protein structure and activity, thereby preventing disease, but they may contribute to cell malfunction when perturbed. For example, sHSPs prevent cataract in the mammalian lens and guard against ischemic and reperfusion injury due to heart attack and stroke. On the other hand, mutated sHSPs are implicated in diseases such as desmin-related myopathy and they have an uncertain relationship to neurological disorders including Parkinson's and Alzheimer's disease. This review explores the involvement of sHSPs in disease and their potential for therapeutic intervention.
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Affiliation(s)
- Yu Sun
- Department of Biology, Dalhousie University, Halifax, Canada
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Bès S, Vandroux D, Tissier C, Devillard L, Brochot A, Tatou E, Duvillard L, Rochette L, Athias P. Direct, pleiotropic protective effect of cyclosporin A against simulated ischemia-induced injury in isolated cardiomyocytes. Eur J Pharmacol 2005; 511:109-20. [PMID: 15792778 DOI: 10.1016/j.ejphar.2005.02.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2004] [Revised: 02/07/2005] [Accepted: 02/09/2005] [Indexed: 11/30/2022]
Abstract
Cyclosporin A is an immunosuppressor that prolongs graft survival but its use is limited by cardiotoxicity. The effects of cyclosporin A on several functional and biological characteristics were thus evaluated in rat cardiomyocytes in normal conditions and in a substrate-free, hypoxia-reoxygenation model of ischemia-reperfusion. Cyclosporin A (100 and 1000 ng/ml) did not induce cardiocytotoxicity in basal conditions. Simulated ischemia gradually decreased and then blocked the spontaneous electromechanical activity. Cyclosporin A at 100 and 1000 ng/ml permitted the maintenance of electromechanical functions that were abolished in control cells. Cyclosporin A also improved the post-"ischemic" functional recovery. Cyclosporin A reduced the "ischemia"-induced lactate dehydrogenase and troponine I releases and the successive rises in heat shock protein mRNA observed after "ischemia" and reoxygenation. Moreover, cyclosporin A improved the resumption of the mitochondrial function. To conclude, cyclosporin A displayed a direct, pleiotropic protection of isolated cardiomyocytes against physiological, metabolic, structural and stress signaling changes induced by ischemia-reperfusion mimicked in vitro.
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Affiliation(s)
- Sandrine Bès
- Laboratory of Cardiovascular Physiopathology and Pharmacology, Institute of Cardiovascular Research, University Hospital Center, Dijon, France
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