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Polysaccharides from the Edible Mushroom Agaricus bitorquis (Quél.) Sacc. Chaidam Show Anti-hypoxia Activities in Pulmonary Artery Smooth Muscle Cells. Int J Mol Sci 2019; 20:ijms20030637. [PMID: 30717240 PMCID: PMC6387285 DOI: 10.3390/ijms20030637] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 01/17/2019] [Accepted: 01/25/2019] [Indexed: 01/02/2023] Open
Abstract
Three kinds of new water-soluble polysaccharides (FA, FB and FC) were isolated from wild mushroom Agaricus bitorquis (Quél.) Sacc. Chaidam by the classical method “water extraction and alcohol precipitation” and purified by column chromatography. The Mw of FA, FB and FC ranged from 5690 Da to 38,340 Da. The three polysaccharide fractions in the fruiting body were mainly composed of 4 kinds of monosaccharides, including glucose, galactose, mannose, and arabinose, among which glucose and galactose were the major monosaccharides. The FTIR and NMR spectroscopy indicated that the skeleton of three fractions composed of a (1→4)-α-D-glycosidic backbone containing α-D-mannopyranose. In vitro anti-hypoxia activity data showed that three polysaccharide fractions possessed a significant effect on inhibiting PASM cells apoptosis under hypoxia. Among them, FC at the concentration of 200 µg/mL revealed a significant anti-hypoxia effect. These results revealed that the intracellular polysaccharides possessed potent anti-hypoxic activity, which might be related to inhibiting LDH and NADPH oxidase expression and promoting the formation of 5-hydroxytryptamine, dopamine, endothelins, acetylcholine. More importantly, FC showed good performance inducing KV1.5 expression and prohibiting KIR6.2 formation at protein level.
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Tan XH, Zheng XM, Yu LX, He J, Zhu HM, Ge XP, Ren XL, Ye FQ, Bellusci S, Xiao J, Li XK, Zhang JS. Fibroblast growth factor 2 protects against renal ischaemia/reperfusion injury by attenuating mitochondrial damage and proinflammatory signalling. J Cell Mol Med 2017; 21:2909-2925. [PMID: 28544332 PMCID: PMC5661260 DOI: 10.1111/jcmm.13203] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 03/23/2017] [Indexed: 12/13/2022] Open
Abstract
Ischaemia‐reperfusion injury (I/RI) is a common cause of acute kidney injury (AKI). The molecular basis underlying I/RI‐induced renal pathogenesis and measures to prevent or reverse this pathologic process remains to be resolved. Basic fibroblast growth factor (FGF2) is reported to have protective roles of myocardial infarction as well as in several other I/R related disorders. Herein we present evidence that FGF2 exhibits robust protective effect against renal histological and functional damages in a rat I/RI model. FGF2 treatment greatly alleviated I/R‐induced acute renal dysfunction and largely blunted I/R‐induced elevation in serum creatinine and blood urea nitrogen, and also the number of TUNEL‐positive tubular cells in the kidney. Mechanistically, FGF2 substantially ameliorated renal I/RI by mitigating several mitochondria damaging parameters including pro‐apoptotic alteration of Bcl2/Bax expression, caspase‐3 activation, loss of mitochondrial membrane potential and KATP channel integrity. Of note, the protective effect of FGF2 was significantly compromised by the KATP channel blocker 5‐HD. Interestingly, I/RI alone resulted in mild activation of FGFR, whereas FGF2 treatment led to more robust receptor activation. More significantly, post‐I/RI administration of FGF2 also exhibited robust protection against I/RI by reducing cell apoptosis, inhibiting the release of damage‐associated molecular pattern molecule HMBG1 and activation of its downstream inflammatory cytokines such as IL‐1α, IL‐6 and TNF α. Taken together, our data suggest that FGF2 offers effective protection against I/RI and improves animal survival by attenuating mitochondrial damage and HMGB1‐mediated inflammatory response. Therefore, FGF2 has the potential to be used for the prevention and treatment of I/RI‐induced AKI.
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Affiliation(s)
- Xiao-Hua Tan
- Key Laboratory of Biotechnology and Pharmaceutical Engineering, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiao-Meng Zheng
- Key Laboratory of Biotechnology and Pharmaceutical Engineering, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Li-Xia Yu
- Key Laboratory of Biotechnology and Pharmaceutical Engineering, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jian He
- Center for Translational Medicine, Department of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, China
| | - Hong-Mei Zhu
- Key Laboratory of Biotechnology and Pharmaceutical Engineering, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiu-Ping Ge
- Department of Pediatric Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Xiao-Li Ren
- Laboratory Animal Centre, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Fa-Qing Ye
- Key Laboratory of Biotechnology and Pharmaceutical Engineering, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Saverio Bellusci
- Institute of Life Sciences, Wenzhou University, Wenzhou, China.,Excellence Cluster Cardio-Pulmonary System, Justus-Liebig University, Giessen, Germany
| | - Jian Xiao
- Key Laboratory of Biotechnology and Pharmaceutical Engineering, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiao-Kun Li
- Key Laboratory of Biotechnology and Pharmaceutical Engineering, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Institute of Life Sciences, Wenzhou University, Wenzhou, China
| | - Jin-San Zhang
- Key Laboratory of Biotechnology and Pharmaceutical Engineering, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Institute of Life Sciences, Wenzhou University, Wenzhou, China
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Oprisan B, Stoica I, Avadanei MI. Morphological changes induced in erythrocyte membrane by the antiepileptic treatment: An atomic force microscopy study. Microsc Res Tech 2016; 80:364-373. [DOI: 10.1002/jemt.22804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 10/04/2016] [Accepted: 10/22/2016] [Indexed: 11/05/2022]
Affiliation(s)
- Bogdan Oprisan
- Faculty of Medicine, Discipline Biophysics and Medical Physics; “Grigore T. Popa” University of Medicine and Pharmacy; Iasi Romania
| | - Iuliana Stoica
- Department of Polymer Materials Physics; “Petru Poni” Institute of Macromolecular Chemistry; Iasi Romania
| | - Mihaela Iuliana Avadanei
- Department of Polymer Materials Physics; “Petru Poni” Institute of Macromolecular Chemistry; Iasi Romania
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Li L, Hou X, Xu R, Liu C, Tu M. Research review on the pharmacological effects of astragaloside IV. Fundam Clin Pharmacol 2016; 31:17-36. [PMID: 27567103 DOI: 10.1111/fcp.12232] [Citation(s) in RCA: 227] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 07/09/2016] [Accepted: 08/26/2016] [Indexed: 12/11/2022]
Abstract
Astragalus membranaceus Bunge has been used to treat numerous diseases for thousands of years. As the main active substance of Astragalus membranaceus Bunge, astragaloside IV (AS-IV) also demonstrates the potent protective effect on focal cerebral ischemia/reperfusion, cardiovascular disease, pulmonary disease, liver fibrosis, and diabetic nephropathy. Based on studies published during the past several decades, the current state of AS-IV research and the pharmacological effects are detailed, elucidated, and summarized. This review systematically summarizes the pharmacological effects, metabolism mechanism, and the toxicity of AS-IV. AS-IV has multiple pharmacologic effects, including anti-inflammatory, antifibrotic, antioxidative stress, anti-asthma, antidiabetes, immunoregulation, and cardioprotective effect via numerous signaling pathways. According to the existing studies and clinical practices, AS-IV possesses potential for broad application in many diseases.
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Affiliation(s)
- Lei Li
- College of Animal Science, Anhui Science and Technology University, Chuzhou, China
| | - Xiaojiao Hou
- Engineering Research Center of Chinese Traditional Veterinary Medicine, Beijing, China
| | - Rongfang Xu
- Engineering Research Center of Chinese Traditional Veterinary Medicine, Beijing, China
| | - Chang Liu
- College of Animal Science, Anhui Science and Technology University, Chuzhou, China
| | - Menbayaer Tu
- Engineering Research Center of Chinese Traditional Veterinary Medicine, Beijing, China
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Abstract
KATP channels are integral to the functions of many cells and tissues. The use of electrophysiological methods has allowed for a detailed characterization of KATP channels in terms of their biophysical properties, nucleotide sensitivities, and modification by pharmacological compounds. However, even though they were first described almost 25 years ago (Noma 1983, Trube and Hescheler 1984), the physiological and pathophysiological roles of these channels, and their regulation by complex biological systems, are only now emerging for many tissues. Even in tissues where their roles have been best defined, there are still many unanswered questions. This review aims to summarize the properties, molecular composition, and pharmacology of KATP channels in various cardiovascular components (atria, specialized conduction system, ventricles, smooth muscle, endothelium, and mitochondria). We will summarize the lessons learned from available genetic mouse models and address the known roles of KATP channels in cardiovascular pathologies and how genetic variation in KATP channel genes contribute to human disease.
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Affiliation(s)
- Monique N Foster
- Departments of Pediatrics, Physiology & Neuroscience, and Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, New York
| | - William A Coetzee
- Departments of Pediatrics, Physiology & Neuroscience, and Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, New York
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JIANG HAIYANG, ZHAO LEI, DONG XIAOSHEN, HE ANNING, ZHENG CAIWEI, JOHANSSON MAGNUS, KARLSSON ANNA, ZHENG XINYU. Tanshinone IIA enhances bystander cell killing of cancer cells expressing Drosophila melanogaster deoxyribonucleoside kinase in nuclei and mitochondria. Oncol Rep 2015; 34:1487-93. [DOI: 10.3892/or.2015.4102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 06/15/2015] [Indexed: 11/05/2022] Open
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Zhang Q, Bai Y, Yang Z, Tian J, Meng Z. The molecular mechanisms of sodium metabisulfite on the expression of K ATP and L-Ca2+ channels in rat hearts. Regul Toxicol Pharmacol 2015; 72:440-6. [PMID: 26015265 DOI: 10.1016/j.yrtph.2015.05.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Revised: 03/13/2015] [Accepted: 05/19/2015] [Indexed: 11/18/2022]
Abstract
Sodium metabisulfite (SMB) is used as an antioxidant and antimicrobial agent in a variety of drugs and foods. However, there are few reported studies about its side effects. This study is to investigate the SMB effects on the expression of ATP-sensitive K(+) (KATP) and L-type calcium (L-Ca(2+)) channels in rat hearts. The results show that the mRNA and protein levels of the KATP channel subunits Kir6.2 and SUR2A were increased by SMB; on the contrary, SMB at 520 mg/kg significantly decreased the expression of the L-Ca(2+) channel subunits Cav1.2 and Cav1.3. This suggests that SMB can activate the expression of KATP channel by increasing the mRNA and protein levels of Kir6.2 and SUR2A, while it inhibits the expression of L-Ca(2+) channels by decreasing the mRNA and protein levels of Cav1.2 and Cav1.3 in rat hearts. Therefore, the molecular mechanism of the SMB effect on rat hearts might be related to the increased expression of KATP channels and the decreased expression of L-Ca(2+) channels.
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Affiliation(s)
- Quanxi Zhang
- Institute of Environmental Medicine and Toxicology, Institute of Environmental Science, Shanxi University, Taiyuan 030006, China.
| | - Yunlong Bai
- Institute of Environmental Medicine and Toxicology, Institute of Environmental Science, Shanxi University, Taiyuan 030006, China
| | - Zhenhua Yang
- Institute of Environmental Medicine and Toxicology, Institute of Environmental Science, Shanxi University, Taiyuan 030006, China
| | - Jingjing Tian
- Institute of Environmental Medicine and Toxicology, Institute of Environmental Science, Shanxi University, Taiyuan 030006, China
| | - Ziqiang Meng
- Institute of Environmental Medicine and Toxicology, Institute of Environmental Science, Shanxi University, Taiyuan 030006, China
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Abstract
The field of mitochondrial ion channels has recently seen substantial progress, including the molecular identification of some of the channels. An integrative approach using genetics, electrophysiology, pharmacology, and cell biology to clarify the roles of these channels has thus become possible. It is by now clear that many of these channels are important for energy supply by the mitochondria and have a major impact on the fate of the entire cell as well. The purpose of this review is to provide an up-to-date overview of the electrophysiological properties, molecular identity, and pathophysiological functions of the mitochondrial ion channels studied so far and to highlight possible therapeutic perspectives based on current information.
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Csonka C, Kupai K, Bencsik P, Görbe A, Pálóczi J, Zvara A, Puskás LG, Csont T, Ferdinandy P. Cholesterol-enriched diet inhibits cardioprotection by ATP-sensitive K+ channel activators cromakalim and diazoxide. Am J Physiol Heart Circ Physiol 2013; 306:H405-13. [PMID: 24285110 DOI: 10.1152/ajpheart.00257.2013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been previously shown that hyperlipidemia interferes with cardioprotective mechanisms. Here, we investigated the interaction of hyperlipidemia with cardioprotection induced by pharmacological activators of ATP-sensitive K(+) (KATP) channels. Hearts isolated from rats fed a 2% cholesterol-enriched diet or normal diet for 8 wk were subjected to 30 min of global ischemia and 120 min of reperfusion in the presence or absence of KATP modulators. In normal diet-fed rats, either the nonselective KATP activator cromakalim at 10(-5) M or the selective mitochondrial (mito)KATP opener diazoxide at 3 × 10(-5) M significantly decreased infarct size compared with vehicle-treated control rats. Their cardioprotective effect was abolished by coadministration of the nonselective KATP blocker glibenclamide or the selective mitoKATP blocker 5-hydroxydecanoate, respectively. However, in cholesterol-fed rats, the cardioprotective effect of cromakalim or diazoxide was not observed. Therefore, we further investigated how cholesterol-enriched diet influences cardiac KATP channels. Cardiac expression of a KATP subunit gene (Kir6.1) was significantly downregulated in cholesterol-fed rats; however, protein levels of Kir6.1 and Kir6.2 were not changed. The cholesterol diet significantly decreased cardiac ATP, increased lactate content, and enhanced myocardial oxidative stress, as shown by increased cardiac superoxide and dityrosine formation. This is the first demonstration that cardioprotection by KATP channel activators is impaired in cholesterol-enriched diet-induced hyperlipidemia. The background mechanism may include hyperlipidemia-induced attenuation of mitoKATP function by altered energy metabolism and increased oxidative stress in the heart.
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Affiliation(s)
- Csaba Csonka
- Cardiovascular Research Group, Department of Biochemistry, University of Szeged, Szeged, Hungary
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Tan X, Zhang L, Jiang Y, Yang Y, Zhang W, Li Y, Zhang X. Postconditioning ameliorates mitochondrial DNA damage and deletion after renal ischemic injury. Nephrol Dial Transplant 2013; 28:2754-65. [PMID: 24021677 PMCID: PMC3811057 DOI: 10.1093/ndt/gft278] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Reactive oxygen species (ROS) play a major role in causing injury in ischemia-reperfusion (I/R). Mitochondrial DNA (mtDNA) is particularly vulnerable to oxidative damage. We propose that increased mitochondrial ROS production is likely to damage mtDNA, causing further injury to mitochondria, and postconditioning (POC) may ameliorate kidney I/R injury by mitigating mitochondrial damage. METHODS Rats were divided into seven groups: (i) Sham-operated animals with an unconstricted renal artery; (ii) Sham + 5-hydroxydecanoate (5-HD); (iii) I/R; (iv) I/R + 5-HD; (v) POC; (vi) Sham POC and (vii) POC + 5-HD. Renal injury, oxidative DNA damage, mtDNA deletions, mitochondrial membrane potential (MMP) and expression of the ATP-sensitive K(+) (KATP) channel subunit Kir6.2 were evaluated. RESULTS Following 1 h of reperfusion, animals in the I/R group exhibited increased ROS, oxidative mtDNA damage shown by 8-hydroxy-2-deoxyguanosine staining, multiple base pair deletions and decreased MMP. However, POC rats exhibited less ROS, oxidative mtDNA damage and deletions and improved MMP. After 2 days of reperfusion, serum creatinine was elevated in I/R rats and the number of TdT-mediated dUTP nick-end labeled-positive tubular cells was increased and was associated with activation of caspase-3. Therefore, POC prevented the deleterious effects of I/R injury. Furthermore, the expression of mitochondrial Kir6.2 was widely distributed in renal tubular epithelial cells in Sham and POC rats and was lower in I/R rats. All of the protective effects of POC were reversed by the K(+) (KATP) channel blocker 5-HD. CONCLUSION POC may attenuate I/R injury by reducing mitochondrial oxidative stress and mtDNA damage and sustaining MMP.
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Affiliation(s)
- Xiaohua Tan
- Department of Pathology, Norman Bethune School of Medicine, Jilin University, Jilin, China
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Beharier O, Dror S, Levy S, Kahn J, Mor M, Etzion S, Gitler D, Katz A, Muslin AJ, Moran A, Etzion Y. ZnT-1 protects HL-1 cells from simulated ischemia–reperfusion through activation of Ras–ERK signaling. J Mol Med (Berl) 2011; 90:127-38. [DOI: 10.1007/s00109-011-0845-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Revised: 12/04/2011] [Accepted: 12/06/2011] [Indexed: 01/19/2023]
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Astragaloside IV Regulates Expression of ATP-sensitive Potassium Channel Subunits after Ischemia-reperfusion in Rat Ventricular Cardiomyocytes. J TRADIT CHIN MED 2011; 31:321-6. [DOI: 10.1016/s0254-6272(12)60012-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Szabò I, Leanza L, Gulbins E, Zoratti M. Physiology of potassium channels in the inner membrane of mitochondria. Pflugers Arch 2011; 463:231-46. [PMID: 22089812 DOI: 10.1007/s00424-011-1058-7] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2011] [Accepted: 10/30/2011] [Indexed: 02/06/2023]
Abstract
The inner membrane of the ATP-producing organelles of endosymbiotic origin, mitochondria, has long been considered to be poorly permeable to cations and anions, since the strict control of inner mitochondrial membrane permeability is crucial for efficient ATP synthesis. Over the past 30 years, however, it has become clear that various ion channels--along with antiporters and uniporters--are present in the mitochondrial inner membrane, although at rather low abundance. These channels are important for energy supply, and some are a decisive factor in determining whether a cell lives or dies. Their electrophysiological and pharmacological characterisations have contributed importantly to the ongoing elucidation of their pathophysiological roles. This review gives an overview of recent advances in our understanding of the functions of the mitochondrial potassium channels identified so far. Open issues concerning the possible molecular entities giving rise to the observed activities and channel protein targeting to mitochondria are also discussed.
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Affiliation(s)
- Ildikò Szabò
- Department of Biology, University of Padova, Padova, Italy.
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Lu G, Haider HK, Porollo A, Ashraf M. Mitochondria-specific transgenic overexpression of connexin-43 simulates preconditioning-induced cytoprotection of stem cells. Cardiovasc Res 2010; 88:277-86. [PMID: 20833648 PMCID: PMC2952537 DOI: 10.1093/cvr/cvq293] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Revised: 08/26/2010] [Accepted: 09/07/2010] [Indexed: 11/13/2022] Open
Abstract
AIMS We previously reported that preconditioning of stem cells with insulin-like growth factor-1 (IGF-1) translocated connexin-43 (Cx-43) into mitochondria, causing cytoprotection. We posit that these preconditioning effects could be simulated by mitochondria-specific overexpression of Cx-43. METHODS AND RESULTS During IGF-1-induced preconditioning of C57black/6 mouse bone marrow stem cell antigen-1(+) (Sca-1(+)) cells, Cx-43 was mainly translocated onto the mitochondrial inner membrane, which was abrogated by an extracellular signal-regulated kinases 1 and 2 (ERK1/2) blocker PD98059. To investigate the role of mitochondrial Cx-43, we successfully designed a vector coding for full-length mouse Cx-43 with a mitochondria-targeting sequence (mito-Cx-43) and cloned into a shuttle vector (pShuttle-IRES-hrGFP-1) for mitochondria-specific overexpression of Cx-43 (mito-Cx-43). Sca-1(+) cells with mito-Cx-43 reduced cytosolic accumulation of cytochrome c, lowered caspase-3 activity, and improved survival during index oxygen-glucose deprivation as determined by terminal deoxynucleotidyl transferase dUTP nick-end labelling and lactate dehydrogenase assays. Computational analysis revealed a B-cell lymphoma-2 (Bcl-2) homology domain-3 (BH3) motif in Cx-43 with a conserved pattern of amino acids consistent with the Bcl-2 family that regulated cytochrome c release. Moreover, computational secondary structure prediction indicated an extended α-helix in this region, a known condition for BH3-driven protein-protein interactions. CONCLUSION Cx-43 translocation into mitochondria during preconditioning was ERK1/2-dependent. Expression of mito-Cx-43 simulated the cytoprotective effects of preconditioning in stem cells. Structural features of Cx-43 were shared with the Bcl-2 family as determined by computational analysis.
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Affiliation(s)
- Gang Lu
- Department of Pathology and Lab Medicine, University of Cincinnati, Cincinnati, OH 45220, USA
| | - Husnain Kh Haider
- Department of Pathology and Lab Medicine, University of Cincinnati, Cincinnati, OH 45220, USA
| | - Aleksey Porollo
- Department of Environmental Health, University of Cincinnati, Cincinnati, OH, USA
| | - Muhammad Ashraf
- Department of Pathology and Lab Medicine, University of Cincinnati, Cincinnati, OH 45220, USA
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Kozoriz MG, Church J, Ozog MA, Naus CC, Krebs C. Temporary sequestration of potassium by mitochondria in astrocytes. J Biol Chem 2010; 285:31107-19. [PMID: 20667836 DOI: 10.1074/jbc.m109.082073] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Increases in extracellular potassium concentration ([K(+)](o)), which can occur during neuronal activity and under pathological conditions such as ischemia, lead to a variety of potentially detrimental effects on neuronal function. Although astrocytes are known to contribute to the clearance of excess K(+)(o), the mechanisms are not fully understood. We examined the potential role of mitochondria in sequestering K(+) in astrocytes. Astrocytes were loaded with the fluorescent K(+) indicator PBFI and release of K(+) from mitochondria into the cytoplasm was examined after uncoupling the mitochondrial membrane potential with carbonyl cyanide m-chlorophenylhydrazone (CCCP). Under the experimental conditions employed, transient applications of elevated [K(+)](o) led to increases in K(+) within mitochondria, as assessed by increases in the magnitudes of cytoplasmic [K(+)] ([K(+)](i)) transients evoked by brief exposures to CCCP. When mitochondrial K(+) sequestration was impaired by prolonged application of CCCP, there was a robust increase in [K(+)](i) upon exposure to elevated [K(+)](o). Blockade of plasmalemmal K(+) uptake routes by ouabain, Ba(2+), or a mixture of voltage-activated K(+) channel inhibitors reduced K(+) uptake into mitochondria. Also, reductions in mitochondrial K(+) uptake occurred in the presence of mito-K(ATP) channel inhibitors. Rises in [K(+)](i) evoked by brief applications of CCCP following exposure to high [K(+)](o) were also reduced by gap junction blockers and in astrocytes isolated from connexin43-null mice, suggesting that connexins also play a role in K(+) uptake into astrocyte mitochondria. We conclude that mitochondria play a key role in K(+)(o) handling by astrocytes.
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Affiliation(s)
- Michael G Kozoriz
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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Chen FR, Zhang N, Liu P, Zhang YY, Han XH, Cai JF. [Effects of Guanxinkang on expressions of ATP-sensitive potassium channel subunits Kir6.1, Kir6.2, SUR2A and SUR2B in ischemic myocytes of rats]. ACTA ACUST UNITED AC 2010; 8:458-64. [PMID: 20456845 DOI: 10.3736/jcim20100510] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To observe the effects of Guanxinkang injection, a compound traditional Chinese herbal medicine, on ATP-sensitive potassium (K(ATP)) channel subunits in ischemic myocardial cells of rats, and to explore the mechanism of Guanxinkang in protecting myocardial ischemic reperfusion injuries. METHODS Forty-eight Wistar rats were randomly divided into normal group, untreated group, glibenclamide group, pinacidil group, Guanxinkang group and Guanxinkang plus glibenclamide group. The ventricular myocytes were prepared from hearts of normal rats by enzymatic dissociation method. The ischemic ventricular myocytes underwent perfusion with normal Tyrode solution for 10 min, then stopping perfusion 30 min, and followed by 45 min of reperfusion. The glibenclamide, pinacidil and Guanxinkang were added into ventricular myocytes solution directly. Then the solutions were placed at 4 degrees centigrade. After 24-hour freezing at -80 degrees centigrade, mRNA and protein expressions of KATP subunits Kir6.1, Kir6.2, SUR2A and SUR2B were measured by real-time quantitative polymerase chain reaction and Western blotting respectively. RESULTS In normal rat myocardial cells, there were SUR2A, Kir6.1, and Kir6.2 protein and gene expressions but no expression of SUR2B protein. In the untreated group, all subunit mRNA and protein expressions of KATP increased to some extent as compared with the normal group. Pinacidil, a potassium channel opener, significantly increased mRNA and protein expressions of KATP subunits, while the blocker glibenclamide had a reverse effect. Meanwhile, Guanxinkang injection significantly increased mRNA and protein expressions of K(ATP) subunits but with no significant difference as compared with pinacidil. CONCLUSION Guanxinkang injection can obviously enhance the open of KATP channel and thus play a role in cardiovascular protection.
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Affiliation(s)
- Fu-rong Chen
- Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China
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Miro-Casas E, Ruiz-Meana M, Agullo E, Stahlhofen S, Rodríguez-Sinovas A, Cabestrero A, Jorge I, Torre I, Vazquez J, Boengler K, Schulz R, Heusch G, Garcia-Dorado D. Connexin43 in cardiomyocyte mitochondria contributes to mitochondrial potassium uptake. Cardiovasc Res 2009; 83:747-56. [PMID: 19460776 DOI: 10.1093/cvr/cvp157] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
AIMS Connexin43 is present at the inner membrane of cardiomyocyte mitochondria (mCx43), but its function remains unknown. METHODS AND RESULTS In this study we verified the presence of mCx43 by a mass spectrometry-based proteomic approach in purified mitochondrial preparations from mouse myocardium and determined by western blot analysis that the C-terminus of mCx43 is oriented towards the intermembrane space. Cross-linking studies with dimethylsuberimidate indicated the presence of Cx43 hexamers in mitochondrial membranes. The contribution of Cx43 to both mitochondrial dye uptake and K(+) flux was assessed in wild-type mice using hemichannel blockers and Cx43KI32 mice in which Cx43 had been replaced by Cx32. Uptake of the Cx43 hemichannel-permeant dye Lucifer Yellow was reduced in mitochondria from wild-type mice by two hemichannel blockers (carbenoxolone and heptanol) and in Cx43KI32 compared with wild-type mice. Mitochondrial K(+) influx (PBFI fluorescence) was decreased in digitonin-permeabilized cardiomyocytes from Cx32 mutants compared with wild-type mice, and addition of the Cx43 hemichannel blocker 18alpha-glycyrrhetinic acid had an inhibitory effect on mitochondrial K(+) influx in wild-type cardiomyocytes, but not in cardiomyocytes from Cx32 mutants. CONCLUSION These results indicate that mCx43 contributes to mitochondrial K(+) flux in cardiomyocytes, potentially by forming hemichannel-like structures.
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Affiliation(s)
- Elisabet Miro-Casas
- Servicio de Cardiología, Hospital Universitari Vall d'Hebron, Pg. Vall d'Hebron 119, Barcelona 08035, Spain
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Anesthetic-induced preconditioning delays opening of mitochondrial permeability transition pore via protein Kinase C-epsilon-mediated pathway. Anesthesiology 2009; 111:267-74. [PMID: 19568162 DOI: 10.1097/aln.0b013e3181a91957] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Cardioprotection by volatile anesthetic-induced preconditioning (APC) involves activation of protein kinase C (PKC). This study investigated the importance of APC-activated PKC in delaying mitochondrial permeability transition pore (mPTP) opening. METHODS Rat ventricular myocytes were exposed to isoflurane in the presence or absence of nonselective PKC inhibitor chelerythrine or isoform-specific inhibitors of PKC-delta (rottlerin) and PKC-epsilon (myristoylated PKC-epsilon V1-2 peptide), and the mPTP opening time was measured by using confocal microscopy. Ca-induced mPTP opening was measured in mitochondria isolated from rats exposed to isoflurane in the presence and absence of chelerythrine or in mitochondria directly treated with isoflurane after isolation. Translocation of PKC-epsilon was assessed in APC and control cardiomyocytes by Western blotting. RESULTS In cardiomyocytes, APC prolonged time necessary to induce mPTP opening (261 +/- 26 s APC vs. 216 +/- 27 s control; P < 0.05), and chelerythrine abolished this delay to 213 +/- 22 s. The effect of isoflurane was also abolished when PKC-epsilon inhibitor was applied (210 +/- 22 s) but not in the presence of PKC-delta inhibitor (269 +/- 31 s). Western blotting revealed translocation of PKC-epsilon toward mitochondria in APC cells. The Ca concentration required for mPTP opening was significantly higher in mitochondria from APC rats (45 +/- 8 microM x mg control vs. 64 +/- 8 microM x mg APC), and APC effect was reversed with chelerythrine. In contrast, isoflurane did not protect directly treated mitochondria. CONCLUSION APC induces delay of mPTP opening through PKC-epsilon mediated inhibition of mPTP opening, but not through PKC-delta. These results point to the connection between cytosolic and mitochondrial components of cardioprotection by isoflurane.
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Effective pharmacotherapy against oxidative injury: alternative utility of an ATP-sensitive potassium channel opener. J Cardiovasc Pharmacol 2008; 50:411-8. [PMID: 18049309 DOI: 10.1097/fjc.0b013e31812378df] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Cardiomyocyte viability following ischemia-reperfusion critically depends on mitochondrial function. In this regard, potassium channel openers (KCOs) targeting mitochondria have emerged as powerful cardioprotective agents when applied at the onset of ischemia. However, it is controversial whether openers are still protective when applied at the onset of reoxygenation. Here, H9c2 cardiomyocytes and mitochondria isolated from the rat heart ventricle were subjected to ischemia-reoxygenation or oxidative stress in the absence or presence of 100 microM diazoxide, a potassium channel opener. Ischemia-reoxygenation or oxidative stress significantly reduced cell viability, induced structural damage in association with increased mitochondrial protein release, and impaired oxidative phosphorylation. However, treatment with diazoxide before anoxia or at the onset of reoxygenation, as well as during oxidative stress, prevented cell death and mitochondrial dysfunction and preserved cellular and mitochondrial structural integrity. These protective effects were blocked by 5-hydroxydecanoate. Thus, treatment with potassium channel openers even at the time of reoxygenation may provide a significant protection of the myocardium. The protective mechanism is at least in part endogenous to the mitochondria because protection was also observed in isolated mitochondria.
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20
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Marinovic J, Ljubkovic M, Stadnicka A, Bosnjak ZJ, Bienengraeber M. Role of sarcolemmal ATP-sensitive potassium channel in oxidative stress-induced apoptosis: mitochondrial connection. Am J Physiol Heart Circ Physiol 2008; 294:H1317-25. [PMID: 18192220 DOI: 10.1152/ajpheart.00840.2007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
From time of their discovery, sarcolemmal ATP-sensitive K+ (sarcK ATP) channels were thought to have an important protective role in the heart during stress whereby channel opening protects the heart from stress-induced Ca2+ overload and resulting damage. In contrast, some recent studies indicate that sarcK ATP channel closing can lead to cardiac protection. Also, the role of the sarcK ATP channel in apoptotic cell death is unclear. In the present study, the effects of channel inhibition on apoptosis and the specific interaction between the sarcK ATP channel and mitochondria were investigated. Apoptotic cell death of cultured HL-1 and neonatal cardiomyocytes following exposure to oxidative stress was significantly increased in the presence of sarcK ATP channel inhibitor HMR-1098 as evidenced by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling and caspase-3,7 assays. This was paralleled by an increased release of cytochrome c from mitochondria to cytosol, suggesting activation of the mitochondrial death pathway. sarcK ATP channel inhibition during stress had no effect on Bcl-2, Bad, and phospho-Bad, indicating that the increase in apoptosis cannot be attributed to these modulators of the apoptotic pathway. However, monitoring of mitochondrial Ca2+ with rhod-2 fluorescent indicator revealed that mitochondrial Ca2+ accumulation during stress is potentiated in the presence of HMR-1098. In conclusion, this study provides novel evidence that opening of sarcK ATP channels, through a specific Ca2+-related interaction with mitochondria, plays an important role in preventing cardiomyocyte apoptosis and mitochondrial damage during stress.
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Affiliation(s)
- Jasna Marinovic
- Department of Anesthesiology, Medical College of Wisconsin, Miwaukee, WI 53226, USA
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