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Audira G, Lee JS, Vasquez RD, Roldan MJM, Lai YH, Hsiao CD. Assessments of carbon nanotubes toxicities in zebrafish larvae using multiple physiological and molecular endpoints. Chem Biol Interact 2024; 392:110925. [PMID: 38452846 DOI: 10.1016/j.cbi.2024.110925] [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: 07/31/2023] [Revised: 10/01/2023] [Accepted: 02/20/2024] [Indexed: 03/09/2024]
Abstract
In recent years, carbon nanotubes (CNTs) have become one of the most promising materials for the technology industry. However, due to the extensive usage of these materials, they may be released into the environment, and cause toxicities to the organism. Here, their acute toxicities in zebrafish embryos and larvae were evaluated by using various assessments that may provide us with a novel perspective on their effects on aquatic animals. Before conducting the toxicity assessments, the CNTs were characterized as multiwall carbon nanotubes (MWCNTs) functionalized with hydroxyl and carboxyl groups, which improved their solubility and dispersibility. Based on the results, abnormalities in zebrafish behaviors were observed in the exposed groups, indicated by a reduction in tail coiling frequency and alterations in the locomotion as the response toward photo and vibration stimuli that might be due to the disruption in the neuromodulatory system and the formation of reactive oxygen species (ROS) by MWCNTs. Next, based on the respiratory rate assay, exposed larvae consumed more oxygen, which may be due to the injuries in the larval gill by the MWCNTs. Finally, even though no irregularity was observed in the exposed larval cardiac rhythm, abnormalities were shown in their cardiac physiology and blood flow with significant downregulation in several cardiac development-related gene expressions. To sum up, although the following studies are necessary to understand the exact mechanism of their toxicity, the current study demonstrated the environmental implications of MWCNTs in particularly low concentrations and short-term exposure, especially to aquatic organisms.
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Affiliation(s)
- Gilbert Audira
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li, 320314, Taiwan; Department of Chemistry, Chung Yuan Christian University, Chung-Li, 320314, Taiwan
| | - Jiann-Shing Lee
- Department of Applied Physics, National Pingtung University, Pingtung, 900391, Taiwan
| | - Ross D Vasquez
- Department of Pharmacy, Faculty of Pharmacy, University of Santo Tomas, Manila, 1015, Philippines; Research Center for the Natural and Applied Sciences, University of Santo Tomas, Manila, 1015, Philippines; The Graduate School, University of Santo Tomas, Manila, 1015, Philippines
| | - Marri Jmelou M Roldan
- Faculty of Pharmacy, The Graduate School, University of Santo Tomas, Espana Blvd., Manila, 1015, Philippines
| | - Yu-Heng Lai
- Department of Chemistry, Chinese Culture University, Taipei, 11114, Taiwan
| | - Chung-Der Hsiao
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li, 320314, Taiwan; Department of Chemistry, Chung Yuan Christian University, Chung-Li, 320314, Taiwan; Center of Nanotechnology, Chung Yuan Christian University, Chung-Li, 320314, Taiwan; Center for Aquatic Toxicology and Pharmacology, Chung Yuan Christian University, Chung-Li, 320314, Taiwan.
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2
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Lefort B, Gélinas R, Forest A, Bouchard B, Daneault C, Robillard Frayne I, Roy J, Oger C, Greffard K, Galano JM, Durand T, Labarthe F, Bilodeau JF, Ruiz M, Des Rosiers C. Remodeling of lipid landscape in high fat fed very-long chain acyl-CoA dehydrogenase null mice favors pro-arrhythmic polyunsaturated fatty acids and their downstream metabolites. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166843. [PMID: 37558007 DOI: 10.1016/j.bbadis.2023.166843] [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: 02/06/2023] [Revised: 07/20/2023] [Accepted: 08/04/2023] [Indexed: 08/11/2023]
Abstract
Very-long chain acyl-CoA dehydrogenase (VLCAD) catalyzes the initial step of mitochondrial long chain (LC) fatty acid β-oxidation (FAO). Inherited VLCAD deficiency (VLCADD) predisposes to neonatal arrhythmias whose pathophysiology is still not understood. We hypothesized that VLCADD results in global disruption of cardiac complex lipid homeostasis, which may set conditions predisposing to arrhythmia. To test this, we assessed the cardiac lipidome and related molecular markers in seven-month-old VLCAD-/- mice, which mimic to some extent the human cardiac phenotype. Mice were sacrificed in the fed or fasted state after receiving for two weeks a chow or a high-fat diet (HFD), the latter condition being known to worsen symptoms in human VLCADD. Compared to their littermate counterparts, HFD/fasted VLCAD-/- mouse hearts displayed the following lipid alterations: (1) Lower LC, but higher VLC-acylcarnitines accumulation, (2) higher levels of arachidonic acid (AA) and lower docosahexaenoic acid (DHA) contents in glycerophospholipids (GPLs), as well as (3) corresponding changes in pro-arrhythmogenic AA-derived isoprostanes and thromboxane B2 (higher), and anti-arrythmogenic DHA-derived neuroprostanes (lower). These changes were associated with remodeling in the expression of gene or protein markers of (1) GPLs remodeling: higher calcium-dependent phospholipase A2 and lysophosphatidylcholine-acyltransferase 2, (2) calcium handling perturbations, and (3) endoplasmic reticulum stress. Altogether, these results highlight global lipid dyshomeostasis beyond FAO in VLCAD-/- mouse hearts, which may set conditions predisposing the hearts to calcium mishandling and endoplasmic reticulum stress and thereby may contribute to the pathogenesis of arrhythmias in VLCADD in mice as well as in humans.
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Affiliation(s)
- Bruno Lefort
- Montreal Heart Institute Research Centre, Montreal, Canada; Institut des Cardiopathies Congénitales de Tours et FHU Precicare, CHU Tours, Tours, France; INSERM UMR 1069 et Université François Rabelais, Tours, France
| | - Roselle Gélinas
- Montreal Heart Institute Research Centre, Montreal, Canada; Present address: CHU Ste-Justine Research Center, Montreal, Quebec, Canada
| | - Anik Forest
- Montreal Heart Institute Research Centre, Montreal, Canada
| | | | | | | | - Jérôme Roy
- Institut des Biomolécules Max Mousseron, Pôle Chimie Balard Recherche, UMR 5247, Université de Montpellier, CNRS, ENSCM, Montpellier, France; INRAE, Université de Pau et des Pays de l'Adour, E2S UPPA, UMR1419 Nutrition Metabolism and Aquaculture, Aquapôle, F-64310 Saint-Pée-sur-Nivelle, France
| | - Camille Oger
- Institut des Biomolécules Max Mousseron, Pôle Chimie Balard Recherche, UMR 5247, Université de Montpellier, CNRS, ENSCM, Montpellier, France
| | - Karine Greffard
- Axe endocrinologie et néphrologie, CHU de Québec, Université Laval, Québec, Canada
| | - Jean-Marie Galano
- Institut des Biomolécules Max Mousseron, Pôle Chimie Balard Recherche, UMR 5247, Université de Montpellier, CNRS, ENSCM, Montpellier, France
| | - Thierry Durand
- Institut des Biomolécules Max Mousseron, Pôle Chimie Balard Recherche, UMR 5247, Université de Montpellier, CNRS, ENSCM, Montpellier, France
| | | | - Jean-François Bilodeau
- Axe endocrinologie et néphrologie, CHU de Québec, Université Laval, Québec, Canada; Department of Nutrition, Faculty of medicine, Université Laval, Quebec, Canada
| | - Matthieu Ruiz
- Montreal Heart Institute Research Centre, Montreal, Canada; Department of Nutrition, Faculty of medicine, Université de Montréal, Montreal, Canada.
| | - Christine Des Rosiers
- Montreal Heart Institute Research Centre, Montreal, Canada; Department of Nutrition, Faculty of medicine, Université de Montréal, Montreal, Canada.
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3
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Ni X, Yin X, Qi C, Liu C, Chen H, Zhou Y, Ao W, Bao S, Xue J, Yang J, Dong W. Cardiotoxicity of (-)-borneol, (+)-borneol, and isoborneol in zebrafish embryos is associated with Na + /K + -ATPase and Ca 2+ -ATPase inhibition. J Appl Toxicol 2023; 43:373-386. [PMID: 36062847 DOI: 10.1002/jat.4388] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 08/08/2022] [Accepted: 08/30/2022] [Indexed: 11/10/2022]
Abstract
Borneol is an example of traditional Chinese medicine widely used in Asia. There are different isomers of chiral borneol in the market, but its toxicity and effects need further study. In this study, we used zebrafish embryos to examine the effects of exposure to three isomers of borneol [(-)-borneol, (+)-borneol, and isoborneol] on heart development and the association with Na+ /K+ -ATPase from 4 h post-fertilization (4 hpf). The results showed that the three isomers of borneol increased mortality and decreased hatching rate when the zebrafish embryo developed to 72 hpf. All three isomers of borneol (0.01-1.0 mM) significantly reduced heart rate from 48 to 120 hpf and reduced the expression of genes related to Ca2+ -ATPase (cacna1ab and cacna1da) and Na+ /K+ -ATPase (atp1b2b, atp1a3b, and atp1a2). At the same time, the three isomers of borneol significantly reduced the activities of Ca2+ -ATPase and Na+ /K+ -ATPase at 0.1 to 1.0 mM. (+)-Borneol caused the most significant reduction (p < 0.05), followed by isoborneol and (-)-borneol. Na+ /K+ -ATPase was mainly expressed in otic vesicles and protonephridium. All three isomers of borneol reduced Na+ /K+ -ATPase mRNA expression, but isoborneol was the most significant (p < 0.01). Our results indicated that (+)-borneol was the least toxic of the three isomers while the isoborneol showed the most substantial toxic effect, closely related to effects on Na+ /K+ -ATPase.
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Affiliation(s)
- Xuan Ni
- Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao, China.,School of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Xiaoyu Yin
- Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao, China
| | - Chelimuge Qi
- Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao, China
| | - Chunyu Liu
- Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao, China
| | - Hao Chen
- Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao, China
| | - Yini Zhou
- Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao, China
| | - Wuliji Ao
- Inner Mongolia Research Institute of Traditional Mongolian Medicine Engineering technology/College of Mongolian Medicine and Pharmacy, Inner Mongolia Minzu University, Tongliao, China
| | - Shuyin Bao
- The Medical College of Inner Mongolia Minzu University, Tongliao, China
| | - Jiangdong Xue
- Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao, China
| | - Jingfeng Yang
- Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao, China
| | - Wu Dong
- Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao, China
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Zhang H, Zhang H, Wang C, Wang Y, Zou R, Shi C, Guan B, Gamper N, Xu Y. Auxiliary subunits control biophysical properties and response to compound NS5806 of the Kv4 potassium channel complex. FASEB J 2019; 34:807-821. [PMID: 31914636 PMCID: PMC6972550 DOI: 10.1096/fj.201902010rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 10/28/2019] [Accepted: 11/04/2019] [Indexed: 12/19/2022]
Abstract
Kv4 pore‐forming subunits co‐assemble with β‐subunits including KChIP2 and DPP6 and the resultant complexes conduct cardiac transient outward K+ current (Ito). Compound NS5806 has been shown to potentate Ito in canine cardiomyocytes; however, its effects on Ito in other species yet to be determined. We found that NS5806 inhibited native Ito in a concentration‐dependent manner (0.1~30 μM) in both mouse ventricular cardiomyocytes and human‐induced pluripotent stem cell‐derived cardiomyocytes (hiPSC‐CMs), but potentiated Ito in the canine cardiomyocytes. In HEK293 cells co‐transfected with cloned Kv4.3 (or Kv4.2) and β‐subunit KChIP2, NS5806 significantly increased the peak current amplitude and slowed the inactivation. In contrast, NS5806 suppressed the current and accelerated inactivation of the channels when cells were co‐transfected with Kv4.3 (or Kv4.2), KChIP2 and another β‐subunit, DPP6‐L (long isoform). Western blot analysis showed that DPP6‐L was dominantly expressed in both mouse ventricular myocardium and hiPSC‐CMs, while it was almost undetectable in canine ventricular myocardium. In addition, low level of DPP6‐S expression was found in canine heart, whereas levels of KChIP2 expression were comparable among all three species. siRNA knockdown of DPP6 antagonized the Ito inhibition by NS5806 in hiPSC‐CMs. Molecular docking simulation suggested that DPP6‐L may associate with KChIP2 subunits. Mutations of putative KChIP2‐interacting residues of DPP6‐L reversed the inhibitory effect of NS5806 into potentiation of the current. We conclude that a pharmacological modulator can elicit opposite regulatory effects on Kv4 channel complex among different species, depending on the presence of distinct β‐subunits. These findings provide novel insight into the molecular design and regulation of cardiac Ito. Since Ito is a potential therapeutic target for treatment of multiple cardiovascular diseases, our data will facilitate the development of new therapeutic Ito modulators.
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Affiliation(s)
- Hongxue Zhang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Hua Zhang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Chanjuan Wang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Yuhong Wang
- Institute of Masteria Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Ruya Zou
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Chenxia Shi
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Bingcai Guan
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Nikita Gamper
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Yanfang Xu
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
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5
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Wu Y, Zhang Y, Chen M, Yang Q, Zhuang S, Lv L, Zuo Z, Wang C. Exposure to low-level metalaxyl impacts the cardiac development and function of zebrafish embryos. J Environ Sci (China) 2019; 85:1-8. [PMID: 31471016 DOI: 10.1016/j.jes.2019.03.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 03/21/2019] [Accepted: 03/21/2019] [Indexed: 06/10/2023]
Abstract
Metalaxyl is an anilide pesticide that is widely used to control plant diseases caused by Peronosporales species. In order to study the toxic effects, zebrafish embryos were exposed to metalaxyl at nominal concentrations of 5, 50 and 500 ng/L for 72 hr, and the cardiac development and functioning of larvae were observed. The results showed that metalaxyl exposure resulted in increased rates of pericardial edema, heart hemorrhage and cardiac malformation. The distance between the sinus venosus and bulbus arteriosus, stroke volume, cardiac output and heart rate were significantly increased in larvae exposed to 50 and 500 ng/L metalaxyl compared to solvent control larvae. Significant upregulation in the transcription of tbx5, gata4 and myh6 was observed in the 50 and 500 ng/L treatments, and that of nkx2.5 and myl7 was observed in the 5, 50 and 500 ng/L groups. These disturbances may be related to cardiac developmental and functional defects in the larvae. The activity of Na+/K+-ATPase and Ca2+-ATPase was significantly increased in zebrafish embryos exposed to 500 ng/L metalaxyl, and the mRNA levels of genes related to ATPase (atp2a11, atp1b2b, and atp1a3b) (in the 50 and 500 ng/L groups) and calcium channels (cacna1ab) (in the 500 ng/L group) were significantly downregulated; these changes might be associated with heart arrhythmia and functional failure.
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Affiliation(s)
- Yuqiong Wu
- Wuyi University, College of Tea and Food Science, Wuyishan 354300, China.
| | - Ying Zhang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, China.
| | - Meng Chen
- Key Laboratory of Ministry of Education for Subtropical Wetland Ecosystem Research, Xiamen University, Xiamen 361005, China
| | - Qihong Yang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, China
| | - Shanshan Zhuang
- Key Laboratory of Ministry of Education for Subtropical Wetland Ecosystem Research, Xiamen University, Xiamen 361005, China
| | - Liangju Lv
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, China
| | - Zhenghong Zuo
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, China
| | - Chonggang Wang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, China.
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6
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Gui YJ, Yang T, Liu Q, Liao CX, Chen JY, Wang YT, Hu JH, Xu DY. Soluble epoxide hydrolase inhibitors, t-AUCB, regulated microRNA-1 and its target genes in myocardial infarction mice. Oncotarget 2017; 8:94635-94649. [PMID: 29212255 PMCID: PMC5706901 DOI: 10.18632/oncotarget.21831] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 06/20/2017] [Indexed: 02/04/2023] Open
Abstract
Purpose Soluble epoxide hydrolase inhibitors (sEHIs) had been demonstrated to produce cardioprotective effects against ischemia-induced lethal arrhythmias, but the exact mechanisms remain unknown. The present study was designed to investigate whether the beneficial effects of sEHIs are related to regulation of microRNA-1, which was a proarrhythmic factor in the ischemic heart. Methods A mousemyocardial infarction (MI) model was established by ligating the coronary artery. sEHI t-AUCB (0.2, 1, 5 mg/L in drinking-water) was administered daily seven days before MI. The incidence of arrhythmias was assessed by in vivo electrophysiologic studies. miR-1, KCNJ2 (encoding the K+ channel subunit Kir2.1), and GJA1 (encoding connexin 43 [Cx43]) mRNA were measured by real-time PCR; Kir2.1 and Cx43 protein were assessed by western blotting and immunohistochemistry. Results We demonstrated that sEHIs reduced the myocardium infarct size and incidence of inducible arrhythmias in MI mice. Up-regulation of miR-1 and down-regulation of KCNJ2/Kir2.1 and GJA1/Cx43 mRNA/protein were observed in ischemic myocaridum, whereas administration of sEHIs produced an opposite effect. In addition, miR-1 overexpression inhibited expression of the target mRNA and their corresponding proteins, whereas t-AUCB reversed the effects. Our results further revealed that PI3K/Akt signaling pathway might participate in the negatively regulation of miR-1 by sEHi. Conclusions We conclude that sEHIs can repress miR-1, thus stimulate expression of KCNJ2/Kir2.1 and GJA1/Cx43 mRNA/protein in MI mice, suggesting a possible mechanism for its potential therapeutic application in ischemic arrhythmias.
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Affiliation(s)
- Ya-Jun Gui
- Department of Cardiology, Internal Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Tao Yang
- Department of Cardiology, Internal Medicine, Changsha Central Hospital, Changsha, Hunan 410011, China
| | - Qiong Liu
- Department of Cardiology, Internal Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Cai-Xiu Liao
- Department of Geratology, Internal Medicine, The Third Hospital of Changsha, Changsha, Hunan 410011, China
| | - Jing-Yuan Chen
- Department of Cardiology, Internal Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Ya-Ting Wang
- Department of Cardiology, Internal Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Jia-Hui Hu
- Department of Cardiology, Internal Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Dan-Yan Xu
- Department of Cardiology, Internal Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
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7
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Sun XL, Yuan JF, Jin T, Cheng XQ, Wang Q, Guo J, Zhang W, Zhang Y, Lu L, Zhang Z. Physical and functional interaction of Snapin with Cav1.3 calcium channel impacts channel protein trafficking in atrial myocytes. Cell Signal 2016; 30:118-129. [PMID: 27915047 DOI: 10.1016/j.cellsig.2016.11.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 11/10/2016] [Accepted: 11/27/2016] [Indexed: 10/20/2022]
Abstract
The L-type Ca2+ channel (LTCC) Cav1.3 plays a critical role in generating electrical activity in atrial myocytes and cardiac pacemaker cells. However, the molecular and functional basis of Cav1.3 modulation in atrial myocytes has not yet been fully understood. By using the yeast two-hybrid system (Y2H), a Cav1.3-associated protein was screened, which was identified as Snapin. Physical interaction and co-localization between Snapin and Cav1.3 were then confirmed in both the heterologous expression system and mouse atrial myocytes. Direct interaction between them was additionally addressed in a GST pull down assay. Furthermore, both total and membrane expressions of Cav1.3 were significantly impaired by Snapin overexpression, resulting in the ubiquitin-proteasomal degradation of Cav1.3 and a consequent reduction of the densities of whole-cell ICa-L. Snapin-induced down-regulation of Cav1.3 was reversed by SNAP-23 competitively. What is more important is that the depressed-expression of Cav1.3 paralleled with enhanced-expression of Snapin was documented in atrial samples from atrial fibrillation (AF) patients. Our results provide the evidence of a direct regulatory role of Snapin on Cav1.3 channels in atrial myocytes, and highlight a potential role of Snapin in the regulation of Cav1.3 in atrial arrhythmogenesis.
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Affiliation(s)
- Xiao-Li Sun
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing 210023, China
| | - Ju-Fang Yuan
- Anesthesia Department of The Affiliated People's Hospital, Jiangsu University, Zhenjiang 212002, China
| | - Tao Jin
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing 210023, China
| | - Xiao-Qing Cheng
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing 210023, China
| | - Qiang Wang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing 210023, China
| | - Jia Guo
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing 210023, China; Department of Nephrology at the First Affiliated Hospital, Zhengzhou University, Zhengzhou 450052, China
| | - Wei Zhang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing 210023, China
| | - Yin Zhang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing 210023, China
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Science, Nanjing Normal University, Nanjing 210023, China
| | - Zhao Zhang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing 210023, China.
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8
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Xie Y, Gu ZJ, Wu MX, Huang TC, Ou JS, Ni HS, Lin MH, Yuan WL, Wang JF, Chen YX. Disruption of calcium homeostasis by cardiac-specific over-expression of PPAR-γ in mice: A role in ventricular arrhythmia. Life Sci 2016; 167:12-21. [DOI: 10.1016/j.lfs.2016.10.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 10/09/2016] [Accepted: 10/12/2016] [Indexed: 11/29/2022]
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9
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Li W, Li X, Wang B, Chen Y, Xiao A, Zeng D, Ou D, Yan S, Li W, Zheng Q. ZLN005 protects cardiomyocytes against high glucose-induced cytotoxicity by promoting SIRT1 expression and autophagy. Exp Cell Res 2016; 345:25-36. [PMID: 27208585 DOI: 10.1016/j.yexcr.2016.05.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Revised: 05/13/2016] [Accepted: 05/15/2016] [Indexed: 12/21/2022]
Abstract
Diabetic cardiomyopathy increases the risk for the development of heart failure independent of coronary artery disease and hypertension. Either type 1 or type 2 diabetes is often accompanied by varying degrees of hyperglycemia, which has been proven to induce myocardial apoptosis in animal models. Recently, a novel small molecule, ZLN005, has been reported to show antidiabetic efficacy in a mouse model, possibly by induction of PGC-1α expression. In this study, we investigated whether ZLN005 protects cardiomyocytes against high glucose-induced cytotoxicity and the mechanisms involved. Neonatal mouse cardiomyocytes were incubated with media containing 5.5 or 33mM glucose for 24h in the presence or absence of ZLN005. ZLN005 treatment led to ameliorated cardiomyocyte oxidative injury, enhanced cell viability, and reduced apoptosis in the high glucose environment. Western blot analysis revealed that high glucose suppressed cardiomyocyte autophagy, whereas ZLN005 increased the expression of autophagy marker proteins ATG5, beclin1, and LC3 II/LC3 I; this increase was accompanied by increased expression of SIRT1. Furthermore, EX527, a SIRT1-specific inhibitor, weakened the protective effects of ZLN005 on cardiomyocytes subjected to high glucose. Taken together, these results suggest that ZLN005 suppresses high glucose-induced cardiomyocyte injury by promoting SIRT1 expression and autophagy.
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Affiliation(s)
- Wenju Li
- Department of Cardiology, Tangdu Hospital, Fourth Military Medical University, Xinsi Road, Xi'an, China
| | - Xiaoli Li
- Department of Cardiology, Tangdu Hospital, Fourth Military Medical University, Xinsi Road, Xi'an, China
| | - Bin Wang
- Department of Cardiology, Tangdu Hospital, Fourth Military Medical University, Xinsi Road, Xi'an, China
| | - Yan Chen
- Department of Cardiology, Tangdu Hospital, Fourth Military Medical University, Xinsi Road, Xi'an, China
| | - Aiping Xiao
- Department of Pharmacy, Tangdu Hospital, Fourth Military Medical University, Xinsi Road, Xi'an, China
| | - Di Zeng
- Department of Cardiology, Tangdu Hospital, Fourth Military Medical University, Xinsi Road, Xi'an, China
| | - Dongbo Ou
- Department of Cardiology, Tangdu Hospital, Fourth Military Medical University, Xinsi Road, Xi'an, China
| | - Song Yan
- Department of Cardiology, Tangdu Hospital, Fourth Military Medical University, Xinsi Road, Xi'an, China
| | - Wei Li
- Department of Orthopedics, Tangdu Hospital, Fourth Military Medical University, Xinsi Road, Xi'an, China
| | - Qiangsun Zheng
- Department of Cardiology, Tangdu Hospital, Fourth Military Medical University, Xinsi Road, Xi'an, China.
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10
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Mazzocchi G, Sommese L, Palomeque J, Felice JI, Di Carlo MN, Fainstein D, Gonzalez P, Contreras P, Skapura D, McCauley MD, Lascano EC, Negroni JA, Kranias EG, Wehrens XHT, Valverde CA, Mattiazzi A. Phospholamban ablation rescues the enhanced propensity to arrhythmias of mice with CaMKII-constitutive phosphorylation of RyR2 at site S2814. J Physiol 2016; 594:3005-30. [PMID: 26695843 DOI: 10.1113/jp271622] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 12/14/2015] [Indexed: 01/27/2023] Open
Abstract
KEY POINTS Mice with Ca(2+) -calmodulin-dependent protein kinase (CaMKII) constitutive pseudo-phosphorylation of the ryanodine receptor RyR2 at Ser2814 (S2814D(+/+) mice) exhibit a higher open probability of RyR2, higher sarcoplasmic reticulum (SR) Ca(2+) leak in diastole and increased propensity to arrhythmias under stress conditions. We generated phospholamban (PLN)-deficient S2814D(+/+) knock-in mice by crossing two colonies, S2814D(+/+) and PLNKO mice, to test the hypothesis that PLN ablation can prevent the propensity to arrhythmias of S2814D(+/+) mice. PLN ablation partially rescues the altered intracellular Ca(2+) dynamics of S2814D(+/+) hearts and myocytes, but enhances SR Ca(2+) sparks and leak on confocal microscopy. PLN ablation diminishes ventricular arrhythmias promoted by CaMKII phosphorylation of S2814 on RyR2. PLN ablation aborts the arrhythmogenic SR Ca(2+) waves of S2814D(+/+) and transforms them into non-propagating events. A mathematical human myocyte model replicates these results and predicts the increase in SR Ca(2+) uptake required to prevent the arrhythmias induced by a CaMKII-dependent leaky RyR2. ABSTRACT Mice with constitutive pseudo-phosphorylation at Ser2814-RyR2 (S2814D(+/+) ) have increased propensity to arrhythmias under β-adrenergic stress conditions. Although abnormal Ca(2+) release from the sarcoplasmic reticulum (SR) has been linked to arrhythmogenesis, the role played by SR Ca(2+) uptake remains controversial. We tested the hypothesis that an increase in SR Ca(2+) uptake is able to rescue the increased arrhythmia propensity of S2814D(+/+) mice. We generated phospholamban (PLN)-deficient/S2814D(+/+) knock-in mice by crossing two colonies, S2814D(+/+) and PLNKO mice (SD(+/+) /KO). SD(+/+) /KO myocytes exhibited both increased SR Ca(2+) uptake seen in PLN knock-out (PLNKO) myocytes and diminished SR Ca(2+) load (relative to PLNKO), a characteristic of S2814D(+/+) myocytes. Ventricular arrhythmias evoked by catecholaminergic challenge (caffeine/adrenaline) in S2814D(+/+) mice in vivo or programmed electric stimulation and high extracellular Ca(2+) in S2814D(+) /(-) hearts ex vivo were significantly diminished by PLN ablation. At the myocyte level, PLN ablation converted the arrhythmogenic Ca(2+) waves evoked by high extracellular Ca(2+) provocation in S2814D(+/+) mice into non-propagated Ca(2+) mini-waves on confocal microscopy. Myocyte Ca(2+) waves, typical of S2814D(+/+) mice, could be evoked in SD(+/+) /KO cells by partially inhibiting SERCA2a. A mathematical human myocyte model replicated these results and allowed for predicting the increase in SR Ca(2+) uptake required to prevent the arrhythmias induced by a Ca(2+) -calmodulin-dependent protein kinase (CaMKII)-dependent leaky RyR2. Our results demonstrate that increasing SR Ca(2+) uptake by PLN ablation can prevent the arrhythmic events triggered by SR Ca(2+) leak due to CaMKII-dependent phosphorylation of the RyR2-S2814 site and underscore the benefits of increasing SERCA2a activity on SR Ca(2+) -triggered arrhythmias.
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Affiliation(s)
- G Mazzocchi
- Centro de Investigaciones Cardiovasculares, CCT-La Plata-CONICET, Facultad de Cs Médicas, UNLP, La Plata, Argentina
| | - L Sommese
- Centro de Investigaciones Cardiovasculares, CCT-La Plata-CONICET, Facultad de Cs Médicas, UNLP, La Plata, Argentina
| | - J Palomeque
- Centro de Investigaciones Cardiovasculares, CCT-La Plata-CONICET, Facultad de Cs Médicas, UNLP, La Plata, Argentina
| | - J I Felice
- Centro de Investigaciones Cardiovasculares, CCT-La Plata-CONICET, Facultad de Cs Médicas, UNLP, La Plata, Argentina
| | - M N Di Carlo
- Centro de Investigaciones Cardiovasculares, CCT-La Plata-CONICET, Facultad de Cs Médicas, UNLP, La Plata, Argentina
| | - D Fainstein
- Centro de Investigaciones Cardiovasculares, CCT-La Plata-CONICET, Facultad de Cs Médicas, UNLP, La Plata, Argentina
| | - P Gonzalez
- Cátedra de Patología, Facultad de Cs Médicas, UNLP, La Plata, Argentina
| | - P Contreras
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - D Skapura
- Departments of Molecular Physiology and Biophysics, Medicine (in Cardiology), and Pediatrics, Baylor College of Medicine, Cardiovascular Research Institute, Houston, TX, 77030, USA
| | - M D McCauley
- Departments of Molecular Physiology and Biophysics, Medicine (in Cardiology), and Pediatrics, Baylor College of Medicine, Cardiovascular Research Institute, Houston, TX, 77030, USA
| | - E C Lascano
- Departamento de Biología Comparada, Celular y Molecular, Universidad Favaloro, Ciudad Autónoma de Buenos Aires, Argentina
| | - J A Negroni
- Departamento de Biología Comparada, Celular y Molecular, Universidad Favaloro, Ciudad Autónoma de Buenos Aires, Argentina
| | - E G Kranias
- Department of Pharmacology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267
| | - X H T Wehrens
- Departments of Molecular Physiology and Biophysics, Medicine (in Cardiology), and Pediatrics, Baylor College of Medicine, Cardiovascular Research Institute, Houston, TX, 77030, USA
| | - C A Valverde
- Centro de Investigaciones Cardiovasculares, CCT-La Plata-CONICET, Facultad de Cs Médicas, UNLP, La Plata, Argentina
| | - A Mattiazzi
- Centro de Investigaciones Cardiovasculares, CCT-La Plata-CONICET, Facultad de Cs Médicas, UNLP, La Plata, Argentina
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11
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Zhang X, Ai X, Nakayama H, Chen B, Harris DM, Tang M, Xie Y, Szeto C, Li Y, Li Y, Zhang H, Eckhart AD, Koch WJ, Molkentin JD, Chen X. Persistent increases in Ca(2+) influx through Cav1.2 shortens action potential and causes Ca(2+) overload-induced afterdepolarizations and arrhythmias. Basic Res Cardiol 2015; 111:4. [PMID: 26611208 DOI: 10.1007/s00395-015-0523-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 11/19/2015] [Indexed: 12/15/2022]
Abstract
Persistent elevation of Ca(2+) influx due to prolongation of the action potential (AP), chronic activation of the β-adrenergic system and molecular remodeling occurs in stressed and diseased hearts. Increases in Ca(2+) influx are usually linked to prolonged myocyte action potentials and arrhythmias. However, the contribution of chronic enhancement of Cav1.2 activity on cardiac electrical remodeling and arrhythmogenicity has not been completely defined and is the subject of this study. Chronically increased Cav1.2 activity was produced with a cardiac specific, inducible double transgenic (DTG) mouse system overexpressing the β2a subunit of Cav (Cavβ2a). DTG myocytes had increased L-type Ca(2+) current (ICa-L), myocyte shortening, and Ca(2+) transients. DTG mice had enhanced cardiac performance, but died suddenly and prematurely. Telemetric electrocardiograms revealed shortened QT intervals in DTG mice. The action potential duration (APD) was shortened in DTG myocytes due to significant increases of potassium currents and channel abundance. However, shortened AP in DTG myocytes did not fully limit excess Ca(2+) influx and increased the peak and tail ICa-L. Enhanced ICa promoted sarcoplasmic reticulum (SR) Ca(2+) overload, diastolic Ca(2+) sparks and waves, and increased NCX activity, causing increased occurrence of early and delayed afterdepolarizations (EADs and DADs) that may contribute to premature ventricular beats and ventricular tachycardia. AV blocks that could be related to fibrosis of the AV node were also observed. Our study suggests that increasing ICa-L does not necessarily result in AP prolongation but causes SR Ca(2+) overload and fibrosis of AV node and myocardium to induce cellular arrhythmogenicity, arrhythmias, and conduction abnormalities.
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Affiliation(s)
- Xiaoying Zhang
- Daping Hospital, The Third Military Medical University, Chongqing, China.,Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA, 19140, USA
| | - Xiaojie Ai
- Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA, 19140, USA.,School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Hiroyuki Nakayama
- Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati, Cincinnati, OH, 45229, USA
| | - Biyi Chen
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - David M Harris
- College of Medicine, University of Central Florida, Orlando, FL, 32827, USA
| | - Mingxin Tang
- Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA, 19140, USA
| | - Yuping Xie
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Christopher Szeto
- Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA, 19140, USA
| | - Yingxin Li
- Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA, 19140, USA
| | - Ying Li
- Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA, 19140, USA.,The Second Artillery General Hospital, Beijing, 100088, China
| | - Hongyu Zhang
- Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA, 19140, USA
| | | | - Walter J Koch
- Center for Translational Medicine and Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, USA
| | - Jeffery D Molkentin
- Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati, Cincinnati, OH, 45229, USA
| | - Xiongwen Chen
- Daping Hospital, The Third Military Medical University, Chongqing, China. .,Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA, 19140, USA.
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12
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Xie Y, Mai JT, Wang F, Lin YQ, Yuan WL, Luo NS, Fang MC, Wang JF, Chen YX. Effects of C-reactive protein on K(+) channel interaction protein 2 in cardiomyocytes. Am J Transl Res 2015; 7:922-931. [PMID: 26175853 PMCID: PMC4494143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 05/06/2015] [Indexed: 06/04/2023]
Abstract
Several studies have found that C-reactive protein (CRP) was associated with QTc interval prolongation and ventricular arrhythmia. However, little is known about the mechanisms involved. K(+) channel interaction protein 2 (KChIP2) is a necessary subunit for the formation of transient outward potassium current (Ito.f) which plays a critical role in early repolarization and QTc interval of heart. In this study, we aimed to evaluate the effects of CRP on KChIP2 and Ito.f in cardiomyocytes and to explore the potential mechanism. The neonatal mice ventricular cardiomyocytes were cultured and treated with CRP at different concentrations. The expression of KChIP2 was detected by real time quantitative PCR and Western blot. In addition, Ito.f current density was evaluated by whole cell patch clamp techniques. Our results showed that CRP significantly decreased the mRNA and protein expression of KChIP2 in time and doses dependent manners (P < 0.05), and also reduced the current density of Ito.f (P < 0.05). In addition, CRP increased the expression of NF-κB and decreased IκBα expression without significant influence on the expression of ERK1/2 and JNK. Meanwhile, the NF-κB inhibitor PDTC significantly attenuated the effects of CRP on KChIP2 and Ito.f current density. In conclusion, CRP could significantly down-regulate KChIP2 expression and reduce current density of Ito.f partly through NF-κB pathway, suggesting that CRP may directly or indirectly influence QTc interval and arrhythmia via influencing KChIP2 expression and Ito.f current density of cardiomyocytes.
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Affiliation(s)
- Yong Xie
- Department of Cardiology, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen UniversityGuangzhou 510120, China
- Guangdong Province Key Laboratory of Arrhythmia and ElectrophysiologyGuangzhou 510120, China
| | - Jing-Ting Mai
- Department of Cardiology, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen UniversityGuangzhou 510120, China
- Guangdong Province Key Laboratory of Arrhythmia and ElectrophysiologyGuangzhou 510120, China
| | - Fei Wang
- Department of Anaesthesiology, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen UniversityGuangzhou 510120, China
| | - Yong-Qing Lin
- Department of Cardiology, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen UniversityGuangzhou 510120, China
- Guangdong Province Key Laboratory of Arrhythmia and ElectrophysiologyGuangzhou 510120, China
| | - Wo-Liang Yuan
- Department of Cardiology, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen UniversityGuangzhou 510120, China
- Guangdong Province Key Laboratory of Arrhythmia and ElectrophysiologyGuangzhou 510120, China
| | - Nian-Sang Luo
- Department of Cardiology, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen UniversityGuangzhou 510120, China
- Guangdong Province Key Laboratory of Arrhythmia and ElectrophysiologyGuangzhou 510120, China
| | - Ming-Cheng Fang
- Department of Cardiology, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen UniversityGuangzhou 510120, China
- Guangdong Province Key Laboratory of Arrhythmia and ElectrophysiologyGuangzhou 510120, China
| | - Jing-Feng Wang
- Department of Cardiology, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen UniversityGuangzhou 510120, China
- Guangdong Province Key Laboratory of Arrhythmia and ElectrophysiologyGuangzhou 510120, China
| | - Yang-Xin Chen
- Department of Cardiology, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen UniversityGuangzhou 510120, China
- Guangdong Province Key Laboratory of Arrhythmia and ElectrophysiologyGuangzhou 510120, China
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13
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Lu L, Sirish P, Zhang Z, Woltz RL, Li N, Timofeyev V, Knowlton AA, Zhang XD, Yamoah EN, Chiamvimonvat N. Regulation of gene transcription by voltage-gated L-type calcium channel, Cav1.3. J Biol Chem 2014; 290:4663-4676. [PMID: 25538241 DOI: 10.1074/jbc.m114.586883] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Cav1.3 L-type Ca(2+) channel is known to be highly expressed in neurons and neuroendocrine cells. However, we have previously demonstrated that the Cav1.3 channel is also expressed in atria and pacemaking cells in the heart. The significance of the tissue-specific expression of the channel is underpinned by our previous demonstration of atrial fibrillation in a Cav1.3 null mutant mouse model. Indeed, a recent study has confirmed the critical roles of Cav1.3 in the human heart (Baig, S. M., Koschak, A., Lieb, A., Gebhart, M., Dafinger, C., Nürnberg, G., Ali, A., Ahmad, I., Sinnegger-Brauns, M. J., Brandt, N., Engel, J., Mangoni, M. E., Farooq, M., Khan, H. U., Nürnberg, P., Striessnig, J., and Bolz, H. J. (2011) Nat. Neurosci. 14, 77-84). These studies suggest that detailed knowledge of Cav1.3 may have broad therapeutic ramifications in the treatment of cardiac arrhythmias. Here, we tested the hypothesis that there is a functional cross-talk between the Cav1.3 channel and a small conductance Ca(2+)-activated K(+) channel (SK2), which we have documented to be highly expressed in human and mouse atrial myocytes. Specifically, we tested the hypothesis that the C terminus of Cav1.3 may translocate to the nucleus where it functions as a transcriptional factor. Here, we reported for the first time that the C terminus of Cav1.3 translocates to the nucleus where it functions as a transcriptional regulator to modulate the function of Ca(2+)-activated K(+) channels in atrial myocytes. Nuclear translocation of the C-terminal domain of Cav1.3 is directly regulated by intracellular Ca(2+). Utilizing a Cav1.3 null mutant mouse model, we demonstrate that ablation of Cav1.3 results in a decrease in the protein expression of myosin light chain 2, which interacts and increases the membrane localization of SK2 channels.
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Affiliation(s)
- Ling Lu
- From the Department of Internal Medicine, Division of Cardiovascular Medicine, University of California, Davis, California 95616,; the College of Life Sciences, Nanjing Normal University, Nanjing 210046, China.
| | - Padmini Sirish
- From the Department of Internal Medicine, Division of Cardiovascular Medicine, University of California, Davis, California 95616
| | - Zheng Zhang
- From the Department of Internal Medicine, Division of Cardiovascular Medicine, University of California, Davis, California 95616
| | - Ryan L Woltz
- From the Department of Internal Medicine, Division of Cardiovascular Medicine, University of California, Davis, California 95616
| | - Ning Li
- From the Department of Internal Medicine, Division of Cardiovascular Medicine, University of California, Davis, California 95616
| | - Valeriy Timofeyev
- From the Department of Internal Medicine, Division of Cardiovascular Medicine, University of California, Davis, California 95616
| | - Anne A Knowlton
- From the Department of Internal Medicine, Division of Cardiovascular Medicine, University of California, Davis, California 95616,; the Department of Veterans Affairs, Northern California Health Care System, Mather, California 95655
| | - Xiao-Dong Zhang
- From the Department of Internal Medicine, Division of Cardiovascular Medicine, University of California, Davis, California 95616
| | - Ebenezer N Yamoah
- the Department of Physiology, School of Medicine, University of Nevada, Reno, Nevada 89557, and.
| | - Nipavan Chiamvimonvat
- From the Department of Internal Medicine, Division of Cardiovascular Medicine, University of California, Davis, California 95616,; the Department of Veterans Affairs, Northern California Health Care System, Mather, California 95655,.
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14
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Deletion of soluble epoxide hydrolase attenuates cardiac hypertrophy via down-regulation of cardiac fibroblasts-derived fibroblast growth factor-2. Crit Care Med 2014; 42:e345-54. [PMID: 24448199 DOI: 10.1097/ccm.0000000000000226] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Inhibition of soluble epoxide hydrolase (Ephx2) has been shown to play a protective role in cardiac hypertrophy, but the mechanism is not fully understood. We tested the hypothesis that deletion of soluble epoxide hydrolase attenuates cardiac hypertrophy via down-regulation of cardiac fibroblasts-derived fibroblast growth factor-2. DESIGN Prospective, controlled, and randomized animal study. SETTING University laboratory. SUBJECTS Male wild-type C57BL/6 mice and Ephx2 (-/-) mice. INTERVENTIONS Male wild-type or Ephx2 (-/-) mice were subjected to transverse aorta constriction surgery. MEASUREMENTS AND MAIN RESULTS Four weeks after transverse aorta constriction, Ephx2 (-/-) mice did not develop significant cardiac hypertrophy as that of wild-type mice, indicated by no changes in the ratio of heart weight/body weight and ventricular wall thickness after transverse aorta constriction. Cardiac fibroblast growth factor-2 increased in wild-type-transverse aorta constriction group but this did not change in Ephx2 (-/-)-transverse aorta constriction group, and the serum level of fibroblast growth factor-2 did not change in both groups. In vitro, cardiac fibroblasts were stimulated by angiotensin II to analyze the expression of fibroblast growth factor-2. The effect of increased fibroblast growth factor-2 from cardiac fibroblasts induced by angiotensin II was attenuated by soluble epoxide hydrolase deletion. ERK1/2, p38, and AKT kinase were involved in fibroblast growth factor-2 expression regulated by angiotensin II, and soluble epoxide hydrolase deletion lowered the phosphorylation of ERK1/2 not p38 or AKT to mediate fibroblast growth factor-2 expression. In addition, soluble epoxide hydrolase deletion did not attenuate cardiomyocytes hypertrophy induced by exogenous fibroblast growth factor-2. CONCLUSIONS Our present data demonstrated that deletion of soluble epoxide hydrolase prevented cardiac hypertrophy not only directly to cardiomyocytes but also to cardiac fibroblasts by reducing expression of fibroblast growth factor-2.
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15
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Shi C, Wang X, Dong F, Wang Y, Hui J, Lin Z, Yang J, Xu Y. Temporal alterations and cellular mechanisms of transmural repolarization during progression of mouse cardiac hypertrophy and failure. Acta Physiol (Oxf) 2013; 208:95-110. [PMID: 23356774 DOI: 10.1111/apha.12071] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 10/29/2012] [Accepted: 01/23/2013] [Indexed: 01/02/2023]
Abstract
AIM The remodelling of transmural dispersion of repolarization (TDR) in human heart failure (HF) and in different animal models of cardiac hypertrophy or HF remains a controversial topic. We hypothesize that TDR may exhibit temporal alterations, depending on the stage of the disease. METHODS We systematically investigated the temporal alterations of TDR during the development of cardiac hypertrophy and HF in the mouse pressure-overload model using electrophysiological and molecular biology techniques. RESULTS A progressive prolongation of QT interval and changes in the amplitude of the J wave at 2, 5, 9 and 13 weeks were found in anesthetized aorta-banded mice. Action potential duration (APD) at 90% repolarization (APD90) in subendocardial myocytes of the left ventricular free wall remained unchanged at the hypertrophic stage (2 and 5 weeks), but was significantly prolonged in HF mice at 9 and 13 weeks. However, APD90 in subepicardial myocytes exhibited a significant prolongation at 2 weeks and did not progressively extend from 2 weeks to 13 weeks in banded mice. Thus, non-parallel prolongation of APD in subendocardial and subepicardial myocytes led to a reduction in TDR at hypertrophic stage and an amplification of TDR at HF stage. Further experiments revealed that asynchronous down-regulation of voltage-dependent potassium currents (I(to,f), I(K,slow) and I(ss)) and L-type calcium currents (I(Ca-L)) in subendocardial and subepicardial myocytes may contribute to the dynamic remodelling of transmural APD. CONCLUSION The two distinct TDR modes were revealed during the progression of mouse cardiac hypertrophy and failure, indicating that the remodelling of TDR depends on the stage of the disease.
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Affiliation(s)
| | - X. Wang
- The Third Hospital of Hebei Medical University; Shijiazhuang; China
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16
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Simkó J, Szabó Z, Barta K, Ujvárosi D, Nánási P, Lőrincz I. [Molecular and genetic background of sudden cardiac death]. Orv Hetil 2012; 153:1967-83. [PMID: 23220363 DOI: 10.1556/oh.2012.29498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Despite recent findings on the functional, structural and genetic background of sudden cardiac death, the incidence is still relatively high in the entire population. A thorough knowledge on susceptibility, as well as pathophysiology behind the development of malignant arrhythmias will help us to identify individuals at risk and prevent sudden cardiac death. This article presents a review of the current literature on the role of altered intracellular Ca2+ handling, acute myocardial ischaemia, cardiac autonomic innervation, renin-angiotensin-aldosterone system, monogenic and complex heritability in the pathogenesis of sudden cardiac death.
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Affiliation(s)
- József Simkó
- Miskolci Semmelweis Ignác Egészségügyi Központ és Egyetemi Oktatókórház Nonprofit Kft. Belgyógyászati Intézet, Kardiológiai Osztály Miskolc.
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17
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Triclosan impairs excitation-contraction coupling and Ca2+ dynamics in striated muscle. Proc Natl Acad Sci U S A 2012; 109:14158-63. [PMID: 22891308 DOI: 10.1073/pnas.1211314109] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Triclosan (TCS), a high-production-volume chemical used as a bactericide in personal care products, is a priority pollutant of growing concern to human and environmental health. TCS is capable of altering the activity of type 1 ryanodine receptor (RyR1), but its potential to influence physiological excitation-contraction coupling (ECC) and muscle function has not been investigated. Here, we report that TCS impairs ECC of both cardiac and skeletal muscle in vitro and in vivo. TCS acutely depresses hemodynamics and grip strength in mice at doses ≥12.5 mg/kg i.p., and a concentration ≥0.52 μM in water compromises swimming performance in larval fathead minnow. In isolated ventricular cardiomyocytes, skeletal myotubes, and adult flexor digitorum brevis fibers TCS depresses electrically evoked ECC within ∼10-20 min. In myotubes, nanomolar to low micromolar TCS initially potentiates electrically evoked Ca(2+) transients followed by complete failure of ECC, independent of Ca(2+) store depletion or block of RyR1 channels. TCS also completely blocks excitation-coupled Ca(2+) entry. Voltage clamp experiments showed that TCS partially inhibits L-type Ca(2+) currents of cardiac and skeletal muscle, and [(3)H]PN200 binding to skeletal membranes is noncompetitively inhibited by TCS in the same concentration range that enhances [(3)H]ryanodine binding. TCS potently impairs orthograde and retrograde signaling between L-type Ca(2+) and RyR channels in skeletal muscle, and L-type Ca(2+) entry in cardiac muscle, revealing a mechanism by which TCS weakens cardiac and skeletal muscle contractility in a manner that may negatively impact muscle health, especially in susceptible populations.
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Jankyova S, Kmecova J, Cernecka H, Mesarosova L, Musil P, Brnoliakova Z, Kyselovic J, Babal P, Klimas J. Glucose and blood pressure lowering effects of Pycnogenol® are inefficient to prevent prolongation of QT interval in experimental diabetic cardiomyopathy. Pathol Res Pract 2012; 208:452-7. [DOI: 10.1016/j.prp.2012.05.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 03/22/2012] [Accepted: 05/08/2012] [Indexed: 02/05/2023]
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19
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Shi J, Gu P, Zhu Z, Liu J, Chen Z, Sun X, Chen W, Gao X, Zhang Z. Protein phosphatase 2A effectively modulates basal L-type Ca2+ current by dephosphorylating Cav1.2 at serine 1866 in mouse cardiac myocytes. Biochem Biophys Res Commun 2012; 418:792-8. [DOI: 10.1016/j.bbrc.2012.01.105] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 01/21/2012] [Indexed: 10/14/2022]
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20
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Timofeyev V, Porter CA, Tuteja D, Qiu H, Li N, Tang T, Singapuri A, Han PL, Lopez JE, Hammond HK, Chiamvimonvat N. Disruption of adenylyl cyclase type V does not rescue the phenotype of cardiac-specific overexpression of Galphaq protein-induced cardiomyopathy. Am J Physiol Heart Circ Physiol 2010; 299:H1459-67. [PMID: 20709863 DOI: 10.1152/ajpheart.01208.2009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Adenylyl cyclase (AC) is the principal effector molecule in the β-adrenergic receptor pathway. AC(V) and AC(VI) are the two predominant isoforms in mammalian cardiac myocytes. The disparate roles among AC isoforms in cardiac hypertrophy and progression to heart failure have been under intense investigation. Specifically, the salutary effects resulting from the disruption of AC(V) have been established in multiple models of cardiomyopathy. It has been proposed that a continual activation of AC(V) through elevated levels of protein kinase C could play an integral role in mediating a hypertrophic response leading to progressive heart failure. Elevated protein kinase C is a common finding in heart failure and was demonstrated in murine cardiomyopathy from cardiac-specific overexpression of G(αq) protein. Here we assessed whether the disruption of AC(V) expression can improve cardiac function, limit electrophysiological remodeling, or improve survival in the G(αq) mouse model of heart failure. We directly tested the effects of gene-targeted disruption of AC(V) in transgenic mice with cardiac-specific overexpression of G(αq) protein using multiple techniques to assess the survival, cardiac function, as well as structural and electrical remodeling. Surprisingly, in contrast to other models of cardiomyopathy, AC(V) disruption did not improve survival or cardiac function, limit cardiac chamber dilation, halt hypertrophy, or prevent electrical remodeling in G(αq) transgenic mice. In conclusion, unlike other established models of cardiomyopathy, disrupting AC(V) expression in the G(αq) mouse model is insufficient to overcome several parallel pathophysiological processes leading to progressive heart failure.
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Affiliation(s)
- Valeriy Timofeyev
- Division of Cardiovascular Medicine, University of California, Davis, California 95616, USA
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21
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Nagy N, Szűts V, Horváth Z, Seprényi G, Farkas AS, Acsai K, Prorok J, Bitay M, Kun A, Pataricza J, Papp JG, Nánási PP, Varró A, Tóth A. Does small-conductance calcium-activated potassium channel contribute to cardiac repolarization? J Mol Cell Cardiol 2009; 47:656-63. [DOI: 10.1016/j.yjmcc.2009.07.019] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2009] [Revised: 06/19/2009] [Accepted: 07/16/2009] [Indexed: 11/27/2022]
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22
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Li N, Liu JY, Timofeyev V, Qiu H, Hwang SH, Tuteja D, Lu L, Yang J, Mochida H, Low R, Hammock BD, Chiamvimonvat N. Beneficial effects of soluble epoxide hydrolase inhibitors in myocardial infarction model: Insight gained using metabolomic approaches. J Mol Cell Cardiol 2009; 47:835-45. [PMID: 19716829 DOI: 10.1016/j.yjmcc.2009.08.017] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Accepted: 08/08/2009] [Indexed: 01/28/2023]
Abstract
Myocardial infarction (MI) leading to myocardial cell loss represents one of the common causes leading to cardiac failure. We have previously demonstrated the beneficial effects of several potent soluble epoxide hydrolase (sEH) inhibitors in cardiac hypertrophy. sEH catalizes the conversion of epoxyeicosatrienoic acids (EETs) to form the corresponding dihydroxyeicosatrienoic acids (DHETs). EETs are products of cytochrome P450 epoxygenases that have vasodilatory properties. Additionally, EETs inhibit the activation of nuclear factor (NF)-kappaB-mediated gene transcription. Motivated by the potential to uncover a new class of therapeutic agents for cardiovascular diseases which can be effectively used in clinical setting, we directly tested the biological effects of sEH inhibitors (sEHIs) on the progression of cardiac remodeling using a clinically relevant murine model of MI. We demonstrated that sEHIs were highly effective in the prevention of progressive cardiac remodeling post MI. Using metabolomic profiling of the inflammatory lipid mediators, we documented a significant decrease in EETs/DHETs ratio in MI model predicting a heightened inflammatory state. Treatment with sEHIs resulted in a change in the pattern of lipid mediators from one of inflammation towards resolution. Moreover, the oxylipin profiling showed a striking parallel to the changes in inflammatory cytokines in this model. Our study provides evidence for a possible new therapeutic strategy to improve cardiac function post MI.
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Affiliation(s)
- Ning Li
- Division of Cardiovascular Medicine, University of California, Davis, Davis, CA 95616, USA
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23
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Furmanski O, Gajavelli S, Lee JW, Collado ME, Jergova S, Sagen J. Combined extrinsic and intrinsic manipulations exert complementary neuronal enrichment in embryonic rat neural precursor cultures: an in vitro and in vivo analysis. J Comp Neurol 2009; 515:56-71. [PMID: 19399893 DOI: 10.1002/cne.22027] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Numerous central nervous system (CNS) disorders share a common pathology in dysregulation of gamma-aminobutyric acid (GABA) inhibitory signaling. Transplantation of GABA-releasing cells at the site of disinhibition holds promise for alleviating disease symptoms with fewer side effects than traditional drug therapies. We manipulated fibroblast growth factor (FGF)-2 deprivation and mammalian achaete-scute homolog (MASH)1 transcription factor levels in an attempt to amplify the default GABAergic neuronal fate in cultured rat embryonic neural precursor cells (NPCs) for use in transplantation studies. Naïve and MASH1 lentivirus-transduced NPCs were maintained in FGF-2 or deprived of FGF-2 for varying lengths of time. Immunostaining and quantitative analysis showed that GABA- and beta-III-tubulin-immunoreactive cells generally decreased through successive passages, suggesting a loss of neurogenic potential in rat neurospheres expanded in vitro. However, FGF-2 deprivation resulted in a small, but significantly increased population of GABAergic cells derived from passaged neurospheres. In contrast to naïve and GFP lentivirus-transduced clones, MASH1 transduction resulted in increased bromodeoxyuridine (BrdU) incorporation and clonal colony size. Western blotting showed that MASH1 overexpression and FGF-2 deprivation additively increased beta-III-tubulin and decreased cyclic nucleotide phosphodiesterase (CNPase) expression, whereas FGF-2 deprivation alone attenuated glial fibrillary acidic protein (GFAP) expression. These results suggest that low FGF-2 signaling and MASH1 activity can operate in concert to enrich NPC cultures for a GABA neuronal phenotype. When transplanted into the adult rat spinal cord, this combination also yielded GABAergic neurons. These findings indicate that, even for successful utilization of the default GABAergic neuronal precursor fate, a combination of both extrinsic and intrinsic manipulations will likely be necessary to realize the full potential of NSC grafts in restoring function.
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Affiliation(s)
- Orion Furmanski
- The Miami Project to Cure Paralysis, University of Miami, Miller School of Medicine, Miami, Florida 33136, USA
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24
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Nolte IM, Wallace C, Newhouse SJ, Waggott D, Fu J, Soranzo N, Gwilliam R, Deloukas P, Savelieva I, Zheng D, Dalageorgou C, Farrall M, Samani NJ, Connell J, Brown M, Dominiczak A, Lathrop M, Zeggini E, Wain LV, Newton-Cheh C, Eijgelsheim M, Rice K, de Bakker PIW, Pfeufer A, Sanna S, Arking DE, Asselbergs FW, Spector TD, Carter ND, Jeffery S, Tobin M, Caulfield M, Snieder H, Paterson AD, Munroe PB, Jamshidi Y. Common genetic variation near the phospholamban gene is associated with cardiac repolarisation: meta-analysis of three genome-wide association studies. PLoS One 2009; 4:e6138. [PMID: 19587794 PMCID: PMC2704957 DOI: 10.1371/journal.pone.0006138] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Accepted: 06/04/2009] [Indexed: 12/22/2022] Open
Abstract
To identify loci affecting the electrocardiographic QT interval, a measure of cardiac repolarisation associated with risk of ventricular arrhythmias and sudden cardiac death, we conducted a meta-analysis of three genome-wide association studies (GWAS) including 3,558 subjects from the TwinsUK and BRIGHT cohorts in the UK and the DCCT/EDIC cohort from North America. Five loci were significantly associated with QT interval at P<1×10−6. To validate these findings we performed an in silico comparison with data from two QT consortia: QTSCD (n = 15,842) and QTGEN (n = 13,685). Analysis confirmed the association between common variants near NOS1AP (P = 1.4×10−83) and the phospholamban (PLN) gene (P = 1.9×10−29). The most associated SNP near NOS1AP (rs12143842) explains 0.82% variance; the SNP near PLN (rs11153730) explains 0.74% variance of QT interval duration. We found no evidence for interaction between these two SNPs (P = 0.99). PLN is a key regulator of cardiac diastolic function and is involved in regulating intracellular calcium cycling, it has only recently been identified as a susceptibility locus for QT interval. These data offer further mechanistic insights into genetic influence on the QT interval which may predispose to life threatening arrhythmias and sudden cardiac death.
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Affiliation(s)
- Ilja M Nolte
- Unit of Genetic Epidemiology and Bioinformatics, Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
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25
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Soluble epoxide hydrolase plays an essential role in angiotensin II-induced cardiac hypertrophy. Proc Natl Acad Sci U S A 2009; 106:564-9. [PMID: 19126686 DOI: 10.1073/pnas.0811022106] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pathophysiological cardiac hypertrophy is one of the most common causes of heart failure. Epoxyeicosatrienoic acids, hydrolyzed and degraded by soluble epoxide hydrolase (sEH), can function as endothelium-derived hyperpolarizing factors to induce dilation of coronary arteries and thus are cardioprotective. In this study, we investigated the role of sEH in two rodent models of angiotensin II (Ang II)-induced cardiac hypertrophy. The protein level of sEH was elevated in the heart of both spontaneously hypertensive rats and Ang II-infused Wistar rats. Blocking the Ang II type 1 receptor with losartan could abolish this induction. Administration of a potent sEH inhibitor (sEHI) prevented the pathogenesis of the Ang II-induced hypertrophy, as demonstrated by decreased left-ventricular hypertrophy assessed by echocardiography, reduced cardiomyocyte size, and attenuated expression of hypertrophy markers, including atrial natriuretic factor and beta-myosin heavy chain. Because sEH elevation was not observed in exercise- or norepinephrine-induced hypertrophy, the sEH induction was closely associated with Ang II-induced hypertrophy. In vitro, Ang II upregulated sEH and hypertrophy markers in neonatal cardiomyocytes isolated from rat and mouse. Expression of these marker genes was elevated with adenovirus-mediated sEH overexpression but decreased with sEHI treatment. These results were supported by studies in neonatal cardiomyocytes from sEH(-/-) mice. Our results suggest that sEH is specifically upregulated by Ang II, which directly mediates Ang II-induced cardiac hypertrophy. Thus, pharmacological inhibition of sEH would be a useful approach to prevent and treat Ang II-induced cardiac hypertrophy.
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26
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Ablation of sarcolipin enhances sarcoplasmic reticulum calcium transport and atrial contractility. Proc Natl Acad Sci U S A 2007; 104:17867-72. [PMID: 17971438 DOI: 10.1073/pnas.0707722104] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sarcolipin is a novel regulator of cardiac sarcoplasmic reticulum Ca2+ ATPase 2a (SERCA2a) and is expressed abundantly in atria. In this study we investigated the physiological significance of sarcolipin in the heart by generating a mouse model deficient for sarcolipin. The sarcolipin-null mice do not show any developmental abnormalities or any cardiac pathology. The absence of sarcolipin does not modify the expression level of other Ca2+ handling proteins, in particular phospholamban, and its phosphorylation status. Calcium uptake studies revealed that, in the atria, ablation of sarcolipin resulted in an increase in the affinity of the SERCA pump for Ca2+ and the maximum velocity of Ca2+ uptake rates. An important finding is that ablation of sarcolipin resulted in an increase in atrial Ca2+ transient amplitudes, and this resulted in enhanced atrial contractility. Furthermore, atria from sarcolipin-null mice showed a blunted response to isoproterenol stimulation, implicating sarcolipin as a mediator of beta-adrenergic responses in atria. Our study documented that sarcolipin is a key regulator of SERCA2a in atria. Importantly, our data demonstrate the existence of distinct modulators for the SERCA pump in the atria and ventricles.
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27
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Pott C, Henderson SA, Goldhaber JI, Philipson KD. Na+/Ca2+ exchanger knockout mice: plasticity of cardiac excitation-contraction coupling. Ann N Y Acad Sci 2007; 1099:270-5. [PMID: 17446467 DOI: 10.1196/annals.1387.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The Na+/Ca2+ exchanger (NCX) is the main Ca2+ extrusion mechanism of the cardiac myocyte. Nevertheless, cardiac-specific NCX knockout (KO) mice are viable to adulthood. We have identified two adaptations of excitation-contraction coupling (ECC) to the absence of NCX in these animals: (a) a reduction of the L-type Ca2+ current (I(Ca)) with an increase in ECC gain and (b) a shortening of the action potential (AP) to further limit Ca2+ influx. Both mechanisms contribute to Ca2+ homeostasis by reducing Ca2+ influx while maintaining contractility. These adaptations may comprise important feedback mechanisms by which cardiomyocytes may be able to limit Ca2+ influx in situations of compromised Ca2+ extrusion capacity.
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Affiliation(s)
- Christian Pott
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
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28
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Dirksen WP, Lacombe VA, Chi M, Kalyanasundaram A, Viatchenko-Karpinski S, Terentyev D, Zhou Z, Vedamoorthyrao S, Li N, Chiamvimonvat N, Carnes CA, Franzini-Armstrong C, Györke S, Periasamy M. A mutation in calsequestrin, CASQ2D307H, impairs Sarcoplasmic Reticulum Ca2+ handling and causes complex ventricular arrhythmias in mice. Cardiovasc Res 2007; 75:69-78. [PMID: 17449018 PMCID: PMC2717009 DOI: 10.1016/j.cardiores.2007.03.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Revised: 02/19/2007] [Accepted: 03/02/2007] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVE A naturally-occurring mutation in cardiac calsequestrin (CASQ2) at amino acid 307 was discovered in a highly inbred family and hypothesized to cause Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT). The goal of this study was to establish a causal link between CASQ2(D307H) and the CPVT phenotype using an in vivo model. METHODS AND RESULTS Cardiac-specific expression of the CASQ2(D307H) transgene was achieved using the alpha-MHC promoter. Multiple transgenic (TG) mouse lines expressing CASQ2(D307H) from 2- to 6-fold possess structurally normal hearts without any sign of hypertrophy. The hearts displayed normal ventricular function. Myocytes isolated from TG mice had diminished I(Ca)-induced Ca2+ transient amplitude and duration, as well as increased Ca2+ spark frequency. These myocytes, when exposed to isoproterenol and caffeine, displayed disturbances in their rhythmic Ca2+ oscillations and membrane potential, and delayed afterdepolarizations. ECG monitoring revealed that TG mice challenged with isoproterenol and caffeine developed complex ventricular arrhythmias, including non-sustained polymorphic ventricular tachycardia. CONCLUSIONS The findings of the present study demonstrate that expression of mutant CASQ2(D307H) in the mouse heart results in abnormal myocyte Ca2+ handling and predisposes to complex ventricular arrhythmias similar to the CPVT phenotype observed in human patients.
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MESH Headings
- Animals
- Caffeine/pharmacology
- Calcium/metabolism
- Calcium Signaling
- Calsequestrin/genetics
- Cardiotonic Agents/pharmacology
- Death, Sudden, Cardiac/etiology
- Electrocardiography
- Isoproterenol/pharmacology
- Mice
- Mice, Transgenic
- Microscopy, Confocal
- Models, Animal
- Mutation, Missense
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Sarcoplasmic Reticulum/metabolism
- Tachycardia, Ventricular/genetics
- Tachycardia, Ventricular/metabolism
- Tachycardia, Ventricular/pathology
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Affiliation(s)
- Wessel P. Dirksen
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210
| | | | - Mei Chi
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210
| | | | - Serge Viatchenko-Karpinski
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210
- Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210
| | - Dmitry Terentyev
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210
- Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210
| | - Zhixiang Zhou
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210
| | - Srikanth Vedamoorthyrao
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210
- Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210
| | - Ning Li
- Division of Cardiovascular Medicine, University of California, Davis, CA 95616
| | | | | | - Clara Franzini-Armstrong
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104
| | - Sandor Györke
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210
- Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210
| | - Muthu Periasamy
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210
- Corresponding Author: Dept. of Physiology and Cell Biology, 304 Hamilton Hall, 1645 Neil Ave, The Ohio State University College of Medicine, Columbus, OH 43210. Tel.: 614-292-2310; Fax: 614-292-4888;
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29
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Hiranandani N, Raman S, Kalyanasundaram A, Periasamy M, Janssen PML. Frequency-dependent contractile strength in mice over- and underexpressing the sarco(endo)plasmic reticulum calcium-ATPase. Am J Physiol Regul Integr Comp Physiol 2007; 293:R30-6. [PMID: 17255213 DOI: 10.1152/ajpregu.00508.2006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
One of the prominent markers of end-stage heart failure at the molecular level is a decrease in function and/or expression of the sarcoplasmic reticulum ATPase protein [sarco(endo)plasmic reticulum calcium-ATPase, SERCA]. It has been often postulated that a decrease in SERCA pump activity can contribute in a major way to decreased cardiac function. To establish a functional relationship, we assessed how alterations in SERCA activity level affect basic contractile function in healthy myocardium devoid of other significant molecular changes. We investigated baseline contractile function, frequency-dependent activation, and beta-adrenergic response in ultrathin trabeculae isolated from hearts of mice overexpressing SERCA (transgenic, TG), underexpressing SERCA2a (heterozygous knockout, Het), and their respective wild-type (WT) littermates. At physiological temperature and frequency, compared with their respective WT littermates, SERCA1a mice displayed increased developed force at frequencies of 4-8 Hz ( approximately 90% increase at 4 Hz) and force equal to WT mice at 10-14 Hz. Force development at 4 Hz in presence of 1 muM isoproterenol was similar in TG and WT mice. In Het mice, developed force was nearly identical at the lower end of the frequency range (4-8 Hz) but slightly depressed at higher frequency (P < 0.05 at 14 Hz). In presence of 1 muM isoproterenol, developed force at 4 Hz was equal to that in WT mice. Compared with normal levels, increased SERCA activity enhanced force development only at subphysiological frequencies. A reduction in SERCA activity only showed a depression of force at the higher frequency range. Thus generalizations regarding the correlation between SERCA activity and contractility can be highly ambiguous, because this relationship is critically dependent on other factors including stimulation frequency.
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Affiliation(s)
- Nitisha Hiranandani
- Department of Physiology and Cell Biology, Ohio State University, 1645 Neil Avenue, Columbus, OH 43210-1218, USA
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30
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Xu D, Li N, He Y, Timofeyev V, Lu L, Tsai HJ, Kim IH, Tuteja D, Mateo RKP, Singapuri A, Davis BB, Low R, Hammock BD, Chiamvimonvat N. Prevention and reversal of cardiac hypertrophy by soluble epoxide hydrolase inhibitors. Proc Natl Acad Sci U S A 2006; 103:18733-8. [PMID: 17130447 PMCID: PMC1693731 DOI: 10.1073/pnas.0609158103] [Citation(s) in RCA: 197] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sustained cardiac hypertrophy represents one of the most common causes leading to cardiac failure. There is emerging evidence to implicate the involvement of NF-kappaB in the development of cardiac hypertrophy. However, several critical questions remain unanswered. We tested the use of soluble epoxide hydrolase (sEH) inhibitors as a means to enhance the biological activities of epoxyeicosatrienoic acids (EETs) to treat cardiac hypertrophy. sEH catalyzes the conversion of EETs to form the corresponding dihydroxyeicosatrienoic acids. Previous data have suggested that EETs may inhibit the activation of NF-kappaB-mediated gene transcription. We directly demonstrate the beneficial effects of several potent sEH inhibitors (sEHIs) in cardiac hypertrophy. Specifically, we show that sEHIs can prevent the development of cardiac hypertrophy using a murine model of pressure-induced cardiac hypertrophy. In addition, sEHIs reverse the preestablished cardiac hypertrophy caused by chronic pressure overload. We further demonstrate that these compounds potently block the NF-kappaB activation in cardiac myocytes. Moreover, by using in vivo electrophysiologic recordings, our study shows a beneficial effect of the compounds in the prevention of cardiac arrhythmias that occur in association with cardiac hypertrophy. We conclude that the use of sEHIs to increase the level of the endogenous lipid epoxides such as EETs may represent a viable and completely unexplored avenue to reduce cardiac hypertrophy by blocking NF-kappaB activation.
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Affiliation(s)
- Danyan Xu
- *Division of Cardiovascular Medicine
- Department of Cardiology, Internal Medicine, Xiangya Second Hospital, Central-South University, Changsha, Hunan Province 410007, China
| | - Ning Li
- *Division of Cardiovascular Medicine
| | - Yuxia He
- *Division of Cardiovascular Medicine
| | | | - Ling Lu
- *Division of Cardiovascular Medicine
| | - Hsing-Ju Tsai
- Department of Entomology and Cancer Research Center, University of California, Davis, CA 95616
| | - In-Hae Kim
- Department of Entomology and Cancer Research Center, University of California, Davis, CA 95616
| | | | | | | | | | | | - Bruce D. Hammock
- Department of Entomology and Cancer Research Center, University of California, Davis, CA 95616
- To whom correspondence may be addressed. E-mail:
| | - Nipavan Chiamvimonvat
- *Division of Cardiovascular Medicine
- Department of Veterans Affairs, Northern California Health Care System, Mather, CA 95655; and
- **To whom correspondence may be addressed at:
Division of Cardiovascular Medicine, University of California, One Shields Avenue, GBSF 6315, Davis, CA 95616. E-mail:
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31
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Li J, Marionneau C, Zhang R, Shah V, Hell JW, Nerbonne JM, Anderson ME. Calmodulin kinase II inhibition shortens action potential duration by upregulation of K+ currents. Circ Res 2006; 99:1092-9. [PMID: 17038644 DOI: 10.1161/01.res.0000249369.71709.5c] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The multifunctional Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) is activated by elevated intracellular Ca(2+) (Ca(2+)(i)), and mice with chronic myocardial CaMKII inhibition (Inh) resulting from transgenic expression of a CaMKII inhibitory peptide (AC3-I) unexpectedly showed action potential duration (APD) shortening. Inh mice exhibit increased L-type Ca(2+) current (I(Ca)), because of upregulation of protein kinase A (PKA) activity, and decreased CaMKII-dependent phosphorylation of phospholamban (PLN). We hypothesized that CaMKII is a molecular signal linking Ca(2+)(i) to repolarization. Whole cell voltage-clamp recordings revealed that the fast transient outward current (I(to,f)) and the inward rectifier current (I(K1)) were selectively upregulated in Inh, compared with wild-type (WT) and transgenic control, mice. Breeding Inh mice with mice lacking PLN returned I(to,f) and I(K1) to control levels and equalized the APD and QT intervals in Inh mice to control and WT levels. Dialysis of AC3-I into WT cells did not result in increased I(to,f) or I(K1), suggesting that enhanced cardiac repolarization in Inh mice is an adaptive response to chronic CaMKII inhibition rather than an acute effect of reduced CaMKII activity. Increasing PKA activity, by cell dialysis with cAMP, or inhibition of PKA did not affect I(K1) in WT cells. Dialysis of WT cells with cAMP also reduced I(to,f), suggesting that PKA upregulation does not increase repolarizing K(+) currents in Inh mice. These findings provide novel in vivo and cellular evidence that CaMKII links Ca(2+)(i) to cardiac repolarization and suggest that PLN may be a critical CaMKII target for feedback regulation of APD in ventricular myocytes.
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Affiliation(s)
- Jingdong Li
- Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, USA
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32
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Pott C, Ren X, Tran DX, Yang MJ, Henderson S, Jordan MC, Roos KP, Garfinkel A, Philipson KD, Goldhaber JI. Mechanism of shortened action potential duration in Na+-Ca2+ exchanger knockout mice. Am J Physiol Cell Physiol 2006; 292:C968-73. [PMID: 16943244 DOI: 10.1152/ajpcell.00177.2006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In cardiac-specific Na(+)-Ca(2+) exchanger (NCX) knockout (KO) mice, the ventricular action potential (AP) is shortened. The shortening of the AP, as well as a decrease of the L-type Ca(2+) current (I(Ca)), provides a critical mechanism for the maintenance of Ca(2+) homeostasis and contractility in the absence of NCX (Pott C, Philipson KD, Goldhaber JI. Excitation-contraction coupling in Na(+)-Ca(2+) exchanger knockout mice: reduced transsarcolemmal Ca(2+) flux. Circ Res 97: 1288-1295, 2005). To investigate the mechanism that underlies the accelerated AP repolarization, we recorded the transient outward current (I(to)) in patch-clamped myocytes isolated from wild-type (WT) and NCX KO mice. Peak I(to) was increased by 78% and decay kinetics were slowed in KO vs. WT. Consistent with increased I(to), ECGs from KO mice exhibited shortened QT intervals. Expression of the I(to)-generating K(+) channel subunit Kv4.2 and the K(+) channel interacting protein was increased in KO. We used a computer model of the murine AP (Bondarenko VE, Szigeti GP, Bett GC, Kim SJ, and Rasmusson RL. Computer model of action potential of mouse ventricular myocytes. Am J Physiol Heart Circ Physiol 287: 1378-1403, 2004) to determine the relative contributions of increased I(to), reduced I(Ca), and reduced NCX current (I(NCX)) on the shape and kinetics of the AP. Reduction of I(Ca) and elimination of I(NCX) had relatively small effects on the duration of the AP in the computer model. In contrast, AP repolarization was substantially accelerated when I(to) was increased in the computer model. Thus, the increase in I(to), and not the reduction of I(Ca) or I(NCX), is likely to be the major mechanism of AP shortening in KO myocytes. The upregulation of I(to) may comprise an important regulatory mechanism to limit Ca(2+) influx via a reduction of AP duration, thus preventing Ca(2+) overload in situations of reduced myocyte Ca(2+) extrusion capacity.
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Affiliation(s)
- Christian Pott
- Cardiovascular Research Laboratory, MRL 3-645, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-1760, USA
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Bassani RA. Transient outward potassium current and Ca2+ homeostasis in the heart: beyond the action potential. Braz J Med Biol Res 2006; 39:393-403. [PMID: 16501819 DOI: 10.1590/s0100-879x2006000300010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present review deals with Ca2+-independent, K+-carried transient outward current (Ito), an important determinant of the early repolarization phase of the myocardial action potential. The density of total Ito and of its fast and slow components (I(to,f) and I(to,s), respectively), as well as the expression of their molecular correlates (pore-forming protein isoforms Kv4.3/4.2 and Kv1.4, respectively), vary during postnatal development and aging across species and regions of the heart. Changes in Ito may also occur in disease conditions, which may affect the profile of cardiac repolarization and vulnerability to arrhythmias, and also influence excitation-contraction coupling. Decreased Ito density, observed in immature and aging myocardium, as well as during several types of cardiomyopathy and heart failure, may be associated with action potential prolongation, which favors Ca2+ influx during membrane depolarization and limits voltage-dependent Ca2+ efflux via the Na+/Ca2+ exchanger. Both effects contribute to increasing sarcoplasmic reticulum (SR) Ca2+ content (the main source of contraction-activating Ca2+ in mammalian myocardium), which, in addition to the increased Ca2+ influx, should enhance the amount of Ca2+ released by the SR during systole. This change usually takes place under conditions in which SR function is depressed, and may be adaptive since it provides partial compensation for SR deficiency, although possibly at the cost of asynchronous SR Ca2+ release and greater propensity to triggered arrhythmias. Thus, Ito modulation appears to be an additional mechanism by which excitation-contraction coupling in myocardial cells is indirectly regulated.
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Affiliation(s)
- R A Bassani
- Centro de Engenharia Biomédica, Universidade Estadual de Campinas, Campinas, SP, Brazil.
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Abstract
Despite recent advances in preventing sudden cardiac death (SCD) due to cardiac arrhythmia, its incidence in the population at large has remained unacceptably high. Better understanding of the interaction among various functional, structural, and genetic factors underlying the susceptibility to, and initiation of, fatal arrhythmias is a major goal and will provide new tools for the prediction, prevention, and therapy of SCD. Here, we review the role of aberrant intracellular Ca handling, ionic imbalances associated with acute myocardial ischemia, neurohumoral changes, and genetic predisposition in the pathogenesis of SCD due to cardiac arrhythmia. Therapeutic measures to prevent SCD are also discussed.
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Affiliation(s)
- Michael Rubart
- Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis, Indiana 46202-5225, USA.
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Pott C, Philipson KD, Goldhaber JI. Excitation-contraction coupling in Na+-Ca2+ exchanger knockout mice: reduced transsarcolemmal Ca2+ flux. Circ Res 2005; 97:1288-95. [PMID: 16293789 PMCID: PMC1790864 DOI: 10.1161/01.res.0000196563.84231.21] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cardiac-specific Na+-Ca2+ exchanger (NCX) knockout (KO) mice surprisingly survive into adulthood without compensatory changes in protein expression levels. To determine how cardiac function is maintained in the absence of NCX, we investigated membrane currents, intracellular Ca2+, and action potentials (APs) in whole cell patch-clamped myocytes from wild-type (WT) and NCX knockout mice. There was no difference in resting Ca2+ or sarcoplasmic reticular Ca2+ load between KO and WT. During prolonged caffeine exposure, the decrease of the Ca2+ transient was drastically slowed in KO versus WT myocytes, indicating that no alternative Ca2+-extrusion mechanism is upregulated to compensate for the absence of NCX. Peak L-type Ca2+ current (ICa) was reduced by 62% in KO myocytes compared with WT. Nevertheless, the corresponding Ca2+ transients were similar, implying an increase in the gain of excitation-contraction coupling in KO cells. APs recorded from KO cells repolarized more rapidly than in WT. In WT myocytes, applying a KO AP waveform voltage clamp reduced Ca2+ influx via ICa by 59% compared with WT AP waveform clamps. Again, the corresponding Ca2+ transients remained similar. Our findings indicate that NCX KO myocytes limit Ca2+ influx to &20% of that in WT by reducing ICa and by abbreviating the AP. Contractility is maintained by an increase in the gain of excitation-contraction coupling resulting from both a more rapid repolarization of the AP and an as yet unidentified AP-independent mechanism.
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Affiliation(s)
- Christian Pott
- Correspondence to Kenneth D. Philipson, Cardiovascular Research
Laboratory, MRL 3-645, David Geffen School of Medicine, University of
California, Los Angeles, CA 90095-1760. E-mail
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