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Jeon YK, Kwon JW, Jang J, Choi SW, Woo J, Cho SH, Yu BI, Chun YS, Youm JB, Zhang YH, Kim SJ. Lower troponin expression in the right ventricle of rats explains interventricular differences in E-C coupling. J Gen Physiol 2022; 154:212990. [PMID: 35099502 PMCID: PMC8823606 DOI: 10.1085/jgp.202112949] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 01/06/2022] [Indexed: 12/12/2022] Open
Abstract
Despite distinctive functional and anatomic differences, a precise understanding of the cardiac interventricular differences in excitation–contraction (E–C) coupling mechanisms is still lacking. Here, we directly compared rat right and left cardiomyocytes (RVCM and LVCM). Whole-cell patch clamp, the IonOptix system, and fura-2 fluorimetry were used to measure electrical properties (action potential and ionic currents), single-cell contractility, and cytosolic Ca2+ ([Ca2+]i), respectively. Myofilament proteins were analyzed by immunoblotting. RVCM showed significantly shorter action potential duration (APD) and higher density of transient outward K+ current (Ito). However, the triggered [Ca2+]i change (Ca2+ transient) was not different, while the decay rate of the Ca2+ transient was slower in RVCM. Although the relaxation speed was also slower, the sarcomere shortening amplitude (ΔSL) was smaller in RVCM. SERCA activity was ∼60% lower in RVCM, which is partly responsible for the slower decay of the Ca2+ transient. Immunoblot analysis revealed lower expression of the cardiac troponin complex (cTn) in RVCM, implying a smaller Ca2+ buffering capacity (κS), which was proved by in situ analysis. The introduction of these new levels of cTn, Ito, and SERCA into a mathematical model of rat LVCM reproduced the similar Ca2+ transient, slower Ca2+ decay, shorter APD, and smaller ΔSL of RVCM. Taken together, these data show reduced expression of cTn proteins in the RVCM, which provides an explanation for the interventricular difference in the E–C coupling kinetics.
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Affiliation(s)
- Young Keul Jeon
- Department of Physiology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jae Won Kwon
- Department of Physiology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jihyun Jang
- Department of Physiology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.,Department of Surgery, Center for Vascular and Inflammatory Disease, University of Maryland School of Medicine, Baltimore, MD
| | - Seong Woo Choi
- Department of Physiology and Ion Channel Disease Research Center, Dongguk University College of Medicine, Seoul, Republic of Korea.,Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Joohan Woo
- Department of Physiology and Ion Channel Disease Research Center, Dongguk University College of Medicine, Seoul, Republic of Korea
| | - Su Han Cho
- Department of Physiology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Byeong Il Yu
- Department of Physiology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Yang Sook Chun
- Department of Physiology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.,Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jae Boum Youm
- Cardiovascular and Metabolic Disease Center, Department of Physiology, College of Medicine, Inje University, Busan, Republic of Korea
| | - Yin Hua Zhang
- Department of Physiology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.,Yanbian University Hospital, Yanji, China.,Institute of Cardiovascular Sciences, Faculty of Biology, Medicine and Health Sciences, University of Manchester, Manchester, UK
| | - Sung Joon Kim
- Department of Physiology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.,Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.,Wide River Institute of Immunology, Seoul National University College of Medicine, Hongcheon, Republic of Korea
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Kerrick WGL, Xu Y, Percival JM. nNOS splice variants differentially regulate myofilament function but are dispensable for intracellular calcium and force transients in cardiac papillary muscles. PLoS One 2018; 13:e0200834. [PMID: 30028847 PMCID: PMC6054407 DOI: 10.1371/journal.pone.0200834] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 07/02/2018] [Indexed: 11/18/2022] Open
Abstract
Cardiac muscle expresses three neuronal nitric oxide synthase (nNOS) splice variants: nNOSα, nNOSμ and nNOSβ. The functions of these nNOS splice variants in cardiac muscle, particularly myofilament-associated nNOSβ are unclear. To decipher cardiac nNOS splice variant function we investigated myofilament function and intracellular calcium and force transients in demembranated and intact papillary muscles from two lines of nNOS knockout mice. The first line (KN1) lacks nNOSα and nNOSμ. The second line (KN2) lacks active nNOSα, nNOSμ and nNOSβ. Demembranated KN1 papillary muscles exhibited reduced myofilament ATPase activity (-35%) and specific force (-10%) relative to controls. Demembranated KN2 muscles exhibited a smaller decrease in myofilament ATPase activity (-21%), but a greater reduction in specific force (-26%) relative to controls. Myofilament calcium sensitivity in demembranated KN1 and KN2 papillary muscles was similar to controls. Thus, papillary muscle-expressed nNOS splice variants are necessary for control levels of myofilament ATPase activity and force generation, but dispensable for myofilament calcium sensitivity. The greater reduction in myofilament ATPase relative to specific force in KN1, but not KN2 muscle, reduced the energy cost of muscle contraction, suggesting that nNOSβ increased the energetic efficiency of contraction in the absence of nNOSμ and nNOSα. Analyses of intact KN1 and KN2 papillary muscles showed that both intracellular calcium transients and their evoked force transients were similar to controls at stimulation frequencies between 1 and 3 Hz. Therefore, nNOS was dispensable for baseline excitation-contraction coupling. In summary, these data suggest that nNOS splice variants differentially regulate myofilament function, but not baseline calcium handling in papillary muscles. More importantly, they suggest that nNOSβ is a novel modulator of myofilament function, and ultimately the energetic efficiency of cardiac papillary muscle contraction.
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Affiliation(s)
- W Glenn L Kerrick
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Yuanyuan Xu
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Justin M Percival
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, United States of America
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Abstract
Nitric oxide (NO) is an imperative regulator of the cardiovascular system and is a critical mechanism in preventing the pathogenesis and progression of the diseased heart. The scenario of bioavailable NO in the myocardium is complex: 1) NO is derived from both endogenous NO synthases (endothelial, neuronal, and/or inducible NOSs [eNOS, nNOS, and/or iNOS]) and exogenous sources (entero-salivary NO pathway) and the amount of NO from exogenous sources varies significantly; 2) NOSs are located at discrete compartments of cardiac myocytes and are regulated by distinctive mechanisms under stress; 3) NO regulates diverse target proteins through different modes of post-transcriptional modification (soluble guanylate cyclase [sGC]/cyclic guanosine monophosphate [cGMP]/protein kinase G [PKG]-dependent phosphorylation,
S-nitrosylation, and transnitrosylation); 4) the downstream effectors of NO are multidimensional and vary from ion channels in the plasma membrane to signalling proteins and enzymes in the mitochondria, cytosol, nucleus, and myofilament; 5) NOS produces several radicals in addition to NO (e.g. superoxide, hydrogen peroxide, peroxynitrite, and different NO-related derivatives) and triggers redox-dependent responses. However, nNOS inhibits cardiac oxidases to reduce the sources of oxidative stress in diseased hearts. Recent consensus indicates the importance of nNOS protein in cardiac protection under pathological stress. In addition, a dietary regime with high nitrate intake from fruit and vegetables together with unsaturated fatty acids is strongly associated with reduced cardiovascular events. Collectively, NO-dependent mechanisms in healthy and diseased hearts are better understood and shed light on the therapeutic prospects for NO and NOSs in clinical applications for fatal human heart diseases.
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Affiliation(s)
- Yin Hua Zhang
- Department of Physiology & Biomedical Sciences, College of Medicine, Seoul National University, 103 Dae Hak Ro, Chong No Gu, 110-799 Seoul, Korea, South.,Yanbian University Hospital, Yanji, Jilin Province, 133000, China.,Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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Satake Y, Satoh K, Nogi M, Omura J, Godo S, Miyata S, Saito H, Tanaka S, Ikumi Y, Yamashita S, Kaiho Y, Tsutsui M, Arai Y, Shimokawa H. Crucial roles of nitric oxide synthases in β-adrenoceptor-mediated bladder relaxation in mice. Am J Physiol Renal Physiol 2017; 312:F33-F42. [DOI: 10.1152/ajprenal.00137.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 10/11/2016] [Accepted: 10/19/2016] [Indexed: 02/06/2023] Open
Abstract
The specific roles of nitric oxide (NO) synthases (NOSs) in bladder smooth muscle remain to be elucidated. We examined the roles of NOSs in β-adrenoceptor (AR)-mediated bladder relaxation. Male mice (C57BL6) deficient of neuronal NOS [nNOS-knockout (KO)], endothelial NOS (eNOS-KO), neuronal/endothelial NOS (n/eNOS-KO), neuronal/endothelial/inducible NOS (n/e/iNOS-KO), and their controls [wild-type (WT)] were used. Immunohistochemical analysis was performed in the bladder. Then the responses to relaxing agents and the effects of several inhibitors on the relaxing responses were examined in bladder strips precontracted with carbachol. Immunofluorescence staining showed expressions of nNOS and eNOS in the urothelium and smooth muscle of the bladder. Isoproterenol-induced relaxations were significantly reduced in nNOS-KO mice and were further reduced in n/eNOS-KO and n/e/iNOS-KO mice compared with WT mice. The relaxation in n/e/iNOS-KO mice was almost the same as in n/eNOS-KO mice. Inhibition of Ca2+-activated K+ (KCa) channel with charybdotoxin and apamin abolished isoproterenol-induced bladder relaxation in WT mice. Moreover, direct activation of KCa channel with NS1619 caused comparable extent of relaxations among WT, nNOS-KO, and n/eNOS-KO mice. In contrast, NONOate (a NO donor) or hydrogen peroxide (H2O2) (another possible relaxing factor from eNOS) caused minimal relaxations, and catalase (H2O2 scavenger) had no inhibitory effects on isoproterenol-induced relaxations. These results indicate that both nNOS and eNOS are substantially involved in β-AR-mediated bladder relaxations in a NO- or H2O2-independent manner through activation of KCa channels.
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Affiliation(s)
- Yohei Satake
- Department of Urology, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and
| | - Kimio Satoh
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and
| | - Masamichi Nogi
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and
| | - Junichi Omura
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and
| | - Shigeo Godo
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and
| | - Satoshi Miyata
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and
| | - Hiroki Saito
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and
| | - Shuhei Tanaka
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and
| | - Yosuke Ikumi
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and
| | - Shinichi Yamashita
- Department of Urology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yasuhiro Kaiho
- Department of Urology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Masato Tsutsui
- Department of Pharmacology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Yoichi Arai
- Department of Urology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroaki Shimokawa
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and
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Cha M, Kwon Y, Ahn H, Jeong H, Lee YY, Moon M, Baik SH, Kim DK, Song H, Yi EC, Hwang D, Kim H, Mook‐Jung I. Protein-Induced Pluripotent Stem Cells Ameliorate Cognitive Dysfunction and Reduce Aβ Deposition in a Mouse Model of Alzheimer's Disease. Stem Cells Transl Med 2016; 6:293-305. [PMID: 28170178 PMCID: PMC5442740 DOI: 10.5966/sctm.2016-0081] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 06/13/2016] [Indexed: 12/16/2022] Open
Abstract
Transplantation of stem cells into the brain attenuates functional deficits in the central nervous system via cell replacement, the release of specific neurotransmitters, and the production of neurotrophic factors. To identify patient‐specific and safe stem cells for treating Alzheimer's disease (AD), we generated induced pluripotent stem cells (iPSCs) derived from mouse skin fibroblasts by treating protein extracts of embryonic stem cells. These reprogrammed cells were pluripotent but nontumorigenic. Here, we report that protein‐iPSCs differentiated into glial cells and decreased plaque depositions in the 5XFAD transgenic AD mouse model. We also found that transplanted protein‐iPSCs mitigated the cognitive dysfunction observed in these mice. Proteomic analysis revealed that oligodendrocyte‐related genes were upregulated in brains injected with protein‐iPSCs, providing new insights into the potential function of protein‐iPSCs. Taken together, our data indicate that protein‐iPSCs might be a promising therapeutic approach for AD. Stem Cells Translational Medicine2017;6:293–305
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Affiliation(s)
- Moon‐Yong Cha
- Department of Biochemistry and Biomedical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Yoo‐Wook Kwon
- Innovative Research Institute for Cell Therapy, Seoul National University Hospital, Seoul, Republic of Korea
| | - Hyo‐Suk Ahn
- National Research Laboratory for Stem Cell Niche, Seoul National University, Seoul, Republic of Korea
| | - Hyobin Jeong
- Department of New Biology and Center for Plant and Aging Research, Institute for Basic Science, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
| | - Yong Yook Lee
- The Korean Ginseng Research Institute, Daejeon, Republic of Korea
| | - Minho Moon
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon, Republic of Korea
| | - Sung Hoon Baik
- Department of Biochemistry and Biomedical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Dong Kyu Kim
- Department of Biochemistry and Biomedical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Hyundong Song
- Department of Biochemistry and Biomedical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Eugene C. Yi
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, School of Medicine and School of Pharmacy, Seoul National University, Seoul, Republic of Korea
| | - Daehee Hwang
- Department of New Biology and Center for Plant and Aging Research, Institute for Basic Science, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
| | - Hyo‐Soo Kim
- Innovative Research Institute for Cell Therapy, Seoul National University Hospital, Seoul, Republic of Korea
- National Research Laboratory for Stem Cell Niche, Seoul National University, Seoul, Republic of Korea
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, School of Medicine and School of Pharmacy, Seoul National University, Seoul, Republic of Korea
| | - Inhee Mook‐Jung
- Department of Biochemistry and Biomedical Sciences, Seoul National University, Seoul, Republic of Korea
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Chaudhury A. Response: "Commentary: A Hypothesis for Examining Skeletal Muscle Biopsy-Derived Sarcolemmal nNOSµ as Surrogate for Enteric nNOSα Function". nNOS(skeletal muscle) may be Evidentiary for Enteric NO-Transmission Despite nNOSµ/α Differences. Front Med (Lausanne) 2016; 3:4. [PMID: 26942180 PMCID: PMC4761842 DOI: 10.3389/fmed.2016.00004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 01/15/2016] [Indexed: 12/15/2022] Open
Affiliation(s)
- Arun Chaudhury
- Arkansas Department of Health and GIM Foundation , Little Rock, AR , USA
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