1
|
Le QA, Trinh TN, Luong PK, Anh VTV, Tran HN, Kim JC, Woo SH. The NADPH oxidase inhibitor diphenyleneiodonium suppresses Ca 2+ signaling and contraction in rat cardiac myocytes. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2024; 28:335-344. [PMID: 38926841 PMCID: PMC11211754 DOI: 10.4196/kjpp.2024.28.4.335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 04/14/2024] [Accepted: 04/15/2024] [Indexed: 06/28/2024]
Abstract
Diphenyleneiodonium (DPI) has been widely used as an inhibitor of NADPH oxidase (Nox) to discover its function in cardiac myocytes under various stimuli. However, the effects of DPI itself on Ca2+ signaling and contraction in cardiac myocytes under control conditions have not been understood. We investigated the effects of DPI on contraction and Ca2+ signaling and their underlying mechanisms using video edge detection, confocal imaging, and whole-cell patch clamp technique in isolated rat cardiac myocytes. Application of DPI suppressed cell shortenings in a concentration-dependent manner (IC50 of ≅0.17 µM) with a maximal inhibition of ~70% at ~100 µM. DPI decreased the magnitude of Ca2+ transient and sarcoplasmic reticulum Ca2+ content by 20%-30% at 3 µM that is usually used to remove the Nox activity, with no effect on fractional release. There was no significant change in the half-decay time of Ca2+ transients by DPI. The L-type Ca2+ current (ICa) was decreased concentration-dependently by DPI (IC50 of ≅40.3 µM) with ≅13.1%-inhibition at 3 µM. The frequency of Ca2+ sparks was reduced by 3 µM DPI (by ~25%), which was resistant to a brief removal of external Ca2+ and Na+. Mitochondrial superoxide level was reduced by DPI at 3-100 µM. Our data suggest that DPI may suppress L-type Ca2+ channel and RyR, thereby attenuating Ca2+-induced Ca2+ release and contractility in cardiac myocytes, and that such DPI effects may be related to mitochondrial metabolic suppression.
Collapse
Affiliation(s)
- Qui Anh Le
- College of Pharmacy, Chungnam National University, Daejeon 34134, Korea
| | - Tran Nguyet Trinh
- College of Pharmacy, Chungnam National University, Daejeon 34134, Korea
| | - Phuong Kim Luong
- College of Pharmacy, Chungnam National University, Daejeon 34134, Korea
| | - Vu Thi Van Anh
- College of Pharmacy, Chungnam National University, Daejeon 34134, Korea
| | - Ha Nam Tran
- College of Pharmacy, Chungnam National University, Daejeon 34134, Korea
| | - Joon-Chul Kim
- College of Pharmacy, Chungnam National University, Daejeon 34134, Korea
- Nexel Co. Ltd., Seoul 07802, Korea
| | - Sun-Hee Woo
- College of Pharmacy, Chungnam National University, Daejeon 34134, Korea
| |
Collapse
|
2
|
Zhu Q, Zhao E, Shen Y, Chen Z, Fang W. Photocatalytic C-N cross-coupling mediated by heterogeneous nickel-coordinated carbon nitride. Org Biomol Chem 2023; 21:4276-4281. [PMID: 37144980 DOI: 10.1039/d3ob00388d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
An easy to prepare nickel-coordinated mesoporous graphitic carbon nitride (Ni-mpg-CN) was introduced as a heterogeneous photocatalyst, which efficiently accelerated the photocatalytic C-N cross-coupling of (hetero)aryl bromides and aliphatic amines, delivering the desired monoaminated products in good yields. In addition, the concise synthesis of the pharmaceutical tetracaine was accomplished in the final stage, further highlighting the practical applicability.
Collapse
Affiliation(s)
- Qi Zhu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Chemical Engineering, Nanjing Forestry University, 159 Longpan Road, 210037, Nanjing, China.
| | - En Zhao
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Chemical Engineering, Nanjing Forestry University, 159 Longpan Road, 210037, Nanjing, China.
| | - Yajing Shen
- Institute of Zhejiang University-Quzhou, 99 Zheda Road, 324000, Zhejiang, China
| | - Zupeng Chen
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Chemical Engineering, Nanjing Forestry University, 159 Longpan Road, 210037, Nanjing, China.
| | - Weiwei Fang
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Chemical Engineering, Nanjing Forestry University, 159 Longpan Road, 210037, Nanjing, China.
| |
Collapse
|
3
|
Han Mİ, İmamoğlu N. Design, Synthesis, and Anticancer Evaluation of Novel Tetracaine Hydrazide-Hydrazones. ACS OMEGA 2023; 8:9198-9211. [PMID: 36936335 PMCID: PMC10018687 DOI: 10.1021/acsomega.2c07192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Tetracaine is an ester derivative used as a local anesthetic molecule. In this study, a series of novel Tetracaine derivatives bearing hydrazide-hydrazone moiety were designed, synthesized, and evaluated for anticancer activity. The structures of these compounds were characterized by spectral (1H NMR,13C NMR, FT-IR, and HRMS analyses) methods. All synthesized compounds were screened for anticancer activity against two different human cancer cell lines (Colo-205 and HepG2). Among the synthesized molecules, compounds 2f and 2m showed the most potent anticancer activity against the Colo-205 cell line (IC50 = 50.0 and 20.5 μM, respectively). Compounds 2k, 2p, and 2s demonstrated the best anticancer activity against the HepG2 cell line (IC50 = 30.5, 35.9, and 20.8 μM, respectively). mRNA transcription levels of Bax and caspase-3 genes were determined by real-time polymerase chain reaction (qRT-PCR) analysis of both Colo-205 and HepG2 cell lines. Doxorubicin was used as a positive sensitivity reference standard. qRT-PCR analysis showed that there was a time-dependent rise in the expression levels of Bax and Caspase 3 on apoptosis. Inhibition of apoptotic proteins PI3K, Akt, PTEN, pPTEN, FoXO1, FoXO3a, TXNIP, and p27 was investigated in Colo-205 and HepG2 cells treated with compounds 2f, 2m, 2k, 2p, and 2s by using Western blotting.
Collapse
Affiliation(s)
- M. İhsan Han
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, Erciyes University, Kayseri 38039, Turkey
| | - Nalan İmamoğlu
- Department
of Basic Sciences, Faculty of Pharmacy, Erciyes University, Kayseri 38039, Turkey
| |
Collapse
|
4
|
Dwivedi R, Drumm BT, Alkawadri T, Martin SL, Sergeant GP, Hollywood MA, Thornbury KD. The TMEM16A blockers benzbromarone and MONNA cause intracellular Ca2+-release in mouse bronchial smooth muscle cells. Eur J Pharmacol 2023; 947:175677. [PMID: 36967079 DOI: 10.1016/j.ejphar.2023.175677] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 03/13/2023] [Accepted: 03/22/2023] [Indexed: 03/29/2023]
Abstract
We investigated effects of TMEM16A blockers benzbromarone, MONNA, CaCCinhA01 and Ani9 on isometric contractions in mouse bronchial rings and on intracellular calcium in isolated bronchial myocytes. Separate concentrations of carbachol (0.1-10 μM) were applied for 10 min periods to bronchial rings, producing concentration-dependent contractions that were well maintained throughout each application period. Benzbromarone (1 μM) markedly reduced the contractions with a more pronounced effect on their sustained component (at 10 min) compared to their initial component (at 2 min). Iberiotoxin (0.3 μM) enhanced the contractions, but they were still blocked by benzbromarone. MONNA (3 μM) and CaCCinhA01 (10 μM) had similar effects to benzbromarone, but were less potent. In contrast, Ani9 (10 μM) had no effect on carbachol-induced contractions. Confocal imaging revealed that benzbromarone (0.3 μM), MONNA (1 μM) and CaCCinhA01 (10 μM) increased intracellular calcium in isolated myocytes loaded with Fluo-4AM. In contrast, Ani9 (10 μM) had no effect on intracellular calcium. Benzbromarone and MONNA also increased calcium in calcium-free extracellular solution, but failed to do so when intracellular stores were discharged with caffeine (10 mM). Caffeine was unable to cause further discharge of the store when applied in the presence of benzbromarone. Ryanodine (100 μM) blocked the ability of benzbromarone (0.3 μM) to increase calcium, while tetracaine (100 μM) reversibly reduced the rise in calcium induced by benzbromarone. We conclude that benzbromarone and MONNA caused intracellular calcium release, probably by opening ryanodine receptors. Their ability to block carbachol contractions was likely due to this off-target effect.
Collapse
|
5
|
The use of local anaesthetics in dermatology, aesthetic medicine and plastic surgery: review of the literature. Postepy Dermatol Alergol 2023; 40:22-27. [PMID: 36909916 PMCID: PMC9993209 DOI: 10.5114/ada.2023.125221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 05/24/2021] [Indexed: 03/03/2023] Open
Abstract
The aim of the study is to present the latest information on local anaesthesia in plastic surgery, aesthetic medicine and dermatology based on the available literature. The aim of the work is to present a model of cooperation between an anaesthesiologist, dermatologist, and surgeon, so that the patients feel safe, and, above all, the procedure will be comfortable and painless for them. Regional blocks are an excellent tool to achieve this goal. Achieving this requires commitment and understanding by both the plastic surgeon and the anaesthesiologist.
Collapse
|
6
|
Uddin ME, Eisenmann ED, Li Y, Huang KM, Garrison DA, Talebi Z, Gibson AA, Jin Y, Nepal M, Bonilla IM, Fu Q, Sun X, Millar A, Tarasov M, Jay CE, Cui X, Einolf HJ, Pelis RM, Smith SA, Radwański PB, Sweet DH, König J, Fromm MF, Carnes CA, Hu S, Sparreboom A. MATE1 Deficiency Exacerbates Dofetilide-Induced Proarrhythmia. Int J Mol Sci 2022; 23:8607. [PMID: 35955741 PMCID: PMC9369325 DOI: 10.3390/ijms23158607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 07/30/2022] [Accepted: 07/30/2022] [Indexed: 02/04/2023] Open
Abstract
Dofetilide is a rapid delayed rectifier potassium current inhibitor widely used to prevent the recurrence of atrial fibrillation and flutter. The clinical use of this drug is associated with increases in QTc interval, which predispose patients to ventricular cardiac arrhythmias. The mechanisms involved in the disposition of dofetilide, including its movement in and out of cardiomyocytes, remain unknown. Using a xenobiotic transporter screen, we identified MATE1 (SLC47A1) as a transporter of dofetilide and found that genetic knockout or pharmacological inhibition of MATE1 in mice was associated with enhanced retention of dofetilide in cardiomyocytes and increased QTc prolongation. The urinary excretion of dofetilide was also dependent on the MATE1 genotype, and we found that this transport mechanism provides a mechanistic basis for previously recorded drug-drug interactions of dofetilide with various contraindicated drugs, including bictegravir, cimetidine, ketoconazole, and verapamil. The translational significance of these observations was examined with a physiologically-based pharmacokinetic model that adequately predicted the drug-drug interaction liabilities in humans. These findings support the thesis that MATE1 serves a conserved cardioprotective role by restricting excessive cellular accumulation and warrant caution against the concurrent administration of potent MATE1 inhibitors and cardiotoxic substrates with a narrow therapeutic window.
Collapse
Affiliation(s)
- Muhammad Erfan Uddin
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA; (M.E.U.); (E.D.E.); (Y.L.); (K.M.H.); (D.A.G.); (Z.T.); (A.A.G.); (Y.J.); (M.N.); (Q.F.); (X.S.)
| | - Eric D. Eisenmann
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA; (M.E.U.); (E.D.E.); (Y.L.); (K.M.H.); (D.A.G.); (Z.T.); (A.A.G.); (Y.J.); (M.N.); (Q.F.); (X.S.)
| | - Yang Li
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA; (M.E.U.); (E.D.E.); (Y.L.); (K.M.H.); (D.A.G.); (Z.T.); (A.A.G.); (Y.J.); (M.N.); (Q.F.); (X.S.)
| | - Kevin M. Huang
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA; (M.E.U.); (E.D.E.); (Y.L.); (K.M.H.); (D.A.G.); (Z.T.); (A.A.G.); (Y.J.); (M.N.); (Q.F.); (X.S.)
| | - Dominique A. Garrison
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA; (M.E.U.); (E.D.E.); (Y.L.); (K.M.H.); (D.A.G.); (Z.T.); (A.A.G.); (Y.J.); (M.N.); (Q.F.); (X.S.)
| | - Zahra Talebi
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA; (M.E.U.); (E.D.E.); (Y.L.); (K.M.H.); (D.A.G.); (Z.T.); (A.A.G.); (Y.J.); (M.N.); (Q.F.); (X.S.)
| | - Alice A. Gibson
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA; (M.E.U.); (E.D.E.); (Y.L.); (K.M.H.); (D.A.G.); (Z.T.); (A.A.G.); (Y.J.); (M.N.); (Q.F.); (X.S.)
| | - Yan Jin
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA; (M.E.U.); (E.D.E.); (Y.L.); (K.M.H.); (D.A.G.); (Z.T.); (A.A.G.); (Y.J.); (M.N.); (Q.F.); (X.S.)
| | - Mahesh Nepal
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA; (M.E.U.); (E.D.E.); (Y.L.); (K.M.H.); (D.A.G.); (Z.T.); (A.A.G.); (Y.J.); (M.N.); (Q.F.); (X.S.)
| | - Ingrid M. Bonilla
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH 43210, USA;
| | - Qiang Fu
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA; (M.E.U.); (E.D.E.); (Y.L.); (K.M.H.); (D.A.G.); (Z.T.); (A.A.G.); (Y.J.); (M.N.); (Q.F.); (X.S.)
| | - Xinxin Sun
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA; (M.E.U.); (E.D.E.); (Y.L.); (K.M.H.); (D.A.G.); (Z.T.); (A.A.G.); (Y.J.); (M.N.); (Q.F.); (X.S.)
| | - Alec Millar
- Division of Outcomes and Translational Sciences, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (A.M.); (M.T.); (P.B.R.); (C.A.C.); (S.H.)
| | - Mikhail Tarasov
- Division of Outcomes and Translational Sciences, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (A.M.); (M.T.); (P.B.R.); (C.A.C.); (S.H.)
| | - Christopher E. Jay
- Department of Pharmaceutics, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, USA; (C.E.J.); (D.H.S.)
| | - Xiaoming Cui
- Novartis Institute for Biomedical Research, East Hanover, NJ 07936, USA; (X.C.); (H.J.E.); (R.M.P.)
| | - Heidi J. Einolf
- Novartis Institute for Biomedical Research, East Hanover, NJ 07936, USA; (X.C.); (H.J.E.); (R.M.P.)
| | - Ryan M. Pelis
- Novartis Institute for Biomedical Research, East Hanover, NJ 07936, USA; (X.C.); (H.J.E.); (R.M.P.)
| | - Sakima A. Smith
- OSU Wexner Medical Center, Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University, Columbus, OH 43210, USA;
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Przemysław B. Radwański
- Division of Outcomes and Translational Sciences, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (A.M.); (M.T.); (P.B.R.); (C.A.C.); (S.H.)
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Douglas H. Sweet
- Department of Pharmaceutics, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, USA; (C.E.J.); (D.H.S.)
| | - Jörg König
- Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany; (J.K.); (M.F.F.)
| | - Martin F. Fromm
- Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany; (J.K.); (M.F.F.)
| | - Cynthia A. Carnes
- Division of Outcomes and Translational Sciences, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (A.M.); (M.T.); (P.B.R.); (C.A.C.); (S.H.)
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
- Division of Pharmacy Practice and Science, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Shuiying Hu
- Division of Outcomes and Translational Sciences, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (A.M.); (M.T.); (P.B.R.); (C.A.C.); (S.H.)
| | - Alex Sparreboom
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA; (M.E.U.); (E.D.E.); (Y.L.); (K.M.H.); (D.A.G.); (Z.T.); (A.A.G.); (Y.J.); (M.N.); (Q.F.); (X.S.)
| |
Collapse
|
7
|
Therapeutic Approaches of Ryanodine Receptor-Associated Heart Diseases. Int J Mol Sci 2022; 23:ijms23084435. [PMID: 35457253 PMCID: PMC9031589 DOI: 10.3390/ijms23084435] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 04/11/2022] [Accepted: 04/14/2022] [Indexed: 01/08/2023] Open
Abstract
Cardiac diseases are the leading causes of death, with a growing number of cases worldwide, posing a challenge for both healthcare and research. Therefore, the most relevant aim of cardiac research is to unravel the molecular pathomechanisms and identify new therapeutic targets. Cardiac ryanodine receptor (RyR2), the Ca2+ release channel of the sarcoplasmic reticulum, is believed to be a good therapeutic target in a group of certain heart diseases, collectively called cardiac ryanopathies. Ryanopathies are associated with the impaired function of the RyR, leading to heart diseases such as congestive heart failure (CHF), catecholaminergic polymorphic ventricular tachycardia (CPVT), arrhythmogenic right ventricular dysplasia type 2 (ARVD2), and calcium release deficiency syndrome (CRDS). The aim of the current review is to provide a short insight into the pathological mechanisms of ryanopathies and discuss the pharmacological approaches targeting RyR2.
Collapse
|
8
|
Hosseini-Sarvari M, Akrami Z. Solar and visible-light active nano Ni/g-C 3N 4 photocatalyst for carbon monoxide (CO) and ligand-free carbonylation reactions. Catal Sci Technol 2021. [DOI: 10.1039/d0cy01717e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, we investigate the amino and alkoxycarbonylation reaction between various substituted aryl halides, benzyl iodides, and iodocyclohexane with different types of amines and alcohols in the absence of carbon monoxide gas and ligands.
Collapse
Affiliation(s)
| | - Zahra Akrami
- Department of Chemistry
- Shiraz University
- Shiraz 7194684795
- I.R. Iran
| |
Collapse
|
9
|
Goodman JB, Qin F, Morgan RJ, Chambers JM, Croteau D, Siwik DA, Hobai I, Panagia M, Luptak I, Bachschmid M, Tong X, Pimentel DR, Cohen RA, Colucci WS. Redox-Resistant SERCA [Sarco(endo)plasmic Reticulum Calcium ATPase] Attenuates Oxidant-Stimulated Mitochondrial Calcium and Apoptosis in Cardiac Myocytes and Pressure Overload-Induced Myocardial Failure in Mice. Circulation 2020; 142:2459-2469. [PMID: 33076678 PMCID: PMC7752816 DOI: 10.1161/circulationaha.120.048183] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND SERCA [sarco(endo)plasmic reticulum calcium ATPase] is regulated by oxidative posttranslational modifications at cysteine 674 (C674). Because sarcoplasmic reticulum (SR) calcium has been shown to play a critical role in mediating mitochondrial dysfunction in response to reactive oxygen species, we hypothesized that SERCA oxidation at C674 would modulate the effects of reactive oxygen species on mitochondrial calcium and mitochondria-dependent apoptosis in cardiac myocytes. METHODS Adult rat ventricular myocytes expressing wild-type SERCA2b or a redox-insensitive mutant in which C674 is replaced by serine (C674S) were exposed to H2O2 (100 µmol/Lμ). Free mitochondrial calcium concentration was measured in adult rat ventricular myocytes with a genetically targeted fluorescent probe, and SR calcium content was assessed by measuring caffeine-stimulated release. Mice with heterozygous knock-in of the SERCA C674S mutation were subjected to chronic ascending aortic constriction. RESULTS In adult rat ventricular myocytes expressing wild-type SERCA, H2O2 caused a 25% increase in mitochondrial calcium concentration that was associated with a 50% decrease in SR calcium content, both of which were prevented by the ryanodine receptor inhibitor tetracaine. In cells expressing the C674S mutant, basal SR calcium content was decreased by 31% and the H2O2-stimulated rise in mitochondrial calcium concentration was attenuated by 40%. In wild-type cells, H2O2 caused cytochrome c release and apoptosis, both of which were prevented in C674S-expressing cells. In myocytes from SERCA knock-in mice, basal SERCA activity and SR calcium content were decreased. To test the effect of C674 oxidation on apoptosis in vivo, SERCA knock-in mice were subjected to chronic ascending aortic constriction. In wild-type mice, ascending aortic constriction caused myocyte apoptosis, LV dilation, and systolic failure, all of which were inhibited in SERCA knock-in mice. CONCLUSIONS Redox activation of SERCA C674 regulates basal SR calcium content, thereby mediating the pathologic reactive oxygen species-stimulated rise in mitochondrial calcium required for myocyte apoptosis and myocardial failure.
Collapse
MESH Headings
- Animals
- Apoptosis/drug effects
- Calcium/metabolism
- Calcium Signaling
- Cells, Cultured
- Disease Models, Animal
- Heart Failure/enzymology
- Heart Failure/genetics
- Heart Failure/pathology
- Heart Failure/physiopathology
- Hydrogen Peroxide/toxicity
- Male
- Mice, Inbred C57BL
- Mice, Mutant Strains
- Mitochondria, Heart/drug effects
- Mitochondria, Heart/enzymology
- Mitochondria, Heart/genetics
- Mitochondria, Heart/pathology
- Mutation
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/pathology
- Oxidants/toxicity
- Oxidation-Reduction
- Oxidative Stress/drug effects
- Rats, Sprague-Dawley
- Reactive Oxygen Species/metabolism
- Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics
- Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism
- Ventricular Function, Left
- Ventricular Remodeling
Collapse
Affiliation(s)
- Jena B. Goodman
- Cardiovascular Medicine Section, Boston University School
of Medicine, Boston, MA
- Myocardial Biology Unit, Boston University School of
Medicine, Boston, MA
| | - Fuzhong Qin
- Cardiovascular Medicine Section, Boston University School
of Medicine, Boston, MA
- Myocardial Biology Unit, Boston University School of
Medicine, Boston, MA
| | - Robert J. Morgan
- Cardiovascular Medicine Section, Boston University School
of Medicine, Boston, MA
- Myocardial Biology Unit, Boston University School of
Medicine, Boston, MA
| | - Jordan M. Chambers
- Cardiovascular Medicine Section, Boston University School
of Medicine, Boston, MA
- Myocardial Biology Unit, Boston University School of
Medicine, Boston, MA
| | - Dominique Croteau
- Cardiovascular Medicine Section, Boston University School
of Medicine, Boston, MA
- Myocardial Biology Unit, Boston University School of
Medicine, Boston, MA
| | - Deborah A. Siwik
- Cardiovascular Medicine Section, Boston University School
of Medicine, Boston, MA
- Myocardial Biology Unit, Boston University School of
Medicine, Boston, MA
| | - Ion Hobai
- Cardiovascular Medicine Section, Boston University School
of Medicine, Boston, MA
- Myocardial Biology Unit, Boston University School of
Medicine, Boston, MA
| | - Marcello Panagia
- Cardiovascular Medicine Section, Boston University School
of Medicine, Boston, MA
- Myocardial Biology Unit, Boston University School of
Medicine, Boston, MA
| | - Ivan Luptak
- Cardiovascular Medicine Section, Boston University School
of Medicine, Boston, MA
- Myocardial Biology Unit, Boston University School of
Medicine, Boston, MA
| | - Markus Bachschmid
- Vascular Biology Unit, Boston University School of
Medicine, Boston, MA
| | - XiaoYong Tong
- Vascular Biology Unit, Boston University School of
Medicine, Boston, MA
| | - David R. Pimentel
- Cardiovascular Medicine Section, Boston University School
of Medicine, Boston, MA
- Myocardial Biology Unit, Boston University School of
Medicine, Boston, MA
| | - Richard A. Cohen
- Vascular Biology Unit, Boston University School of
Medicine, Boston, MA
| | - Wilson S. Colucci
- Cardiovascular Medicine Section, Boston University School
of Medicine, Boston, MA
- Myocardial Biology Unit, Boston University School of
Medicine, Boston, MA
| |
Collapse
|
10
|
A Volumetric Study of Tetracaine Hydrochloride in Aqueous and in Aqueous Electrolyte Solutions at Different Temperatures. J SOLUTION CHEM 2020. [DOI: 10.1007/s10953-020-01040-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
11
|
Kim JC, Le QA, Woo SH. Alterations of Ca 2+ signaling and Ca 2+ release sites in cultured ventricular myocytes with intact internal Ca 2+ storage. Biochem Biophys Res Commun 2020; 527:379-386. [PMID: 32321644 DOI: 10.1016/j.bbrc.2020.04.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 04/13/2020] [Indexed: 10/24/2022]
Abstract
Although cultured adult cardiac myocytes in combination with cell-level genetic modifications have been adopted for the study of protein function, the cellular alterations caused by the culture conditions themselves need to be clarified before we can interpret the effects of genetically altered proteins. We systematically compared the cellular morphology, global Ca2+ signaling, elementary Ca2+ release (sparks), and arrangement of ryanodine receptor (RyR) clusters in short-term (2 days)-cultured adult rat ventricular myocytes with those of freshly isolated myocytes. The transverse (t)-tubules were remarkably decreased (to ∼25%) by culture, and whole-cell capacitance was reduced by ∼35%. The magnitude of depolarization-induced Ca2+ transients decreased to ∼50%, and Ca2+ transient decay was slowed by culture. The culture did not affect sarcoplasmic reticulum (SR) Ca2+ loading. Therefore, fractional Ca2+ release was attenuated by culture. In the cultured cells, the L-type Ca2+ current (ICa) was smaller (∼50% of controls) and its inactivation was slower. In cultured myocytes, there were significantly fewer (∼50% of control) Ca2+ sparks, the local Ca2+ releases through RyR clusters, compared with in freshly isolated cells. Amplitude and kinetics (duration and time-to-peak) of individual sparks were similar, but they showed greater width in cultured cells. Immunolocalization analysis revealed that the cross-striation of RyRs distribution became weaker and less organized, and that the density of RyR clusters decreased in cultured myocytes. Our data suggest that the loss of t-tubules and generation of compromised Ca2+ transients and ICa in short-term adult ventricular cell culture are independent of SR Ca2+ loading status. In addition, the deteriorated arrangement of the RyR-clusters and their decreased density after short-term culture may be partly responsible for fewer Ca2+ sparks and a decrease in global Ca2+ release.
Collapse
Affiliation(s)
- Joon-Chul Kim
- Laboratory of Pathophysiology, College of Pharmacy, Chungnam National University, 99 Daehak-ro, Yuseong-Gu, Daejeon, 34134, South Korea
| | - Qui Anh Le
- Laboratory of Pathophysiology, College of Pharmacy, Chungnam National University, 99 Daehak-ro, Yuseong-Gu, Daejeon, 34134, South Korea
| | - Sun-Hee Woo
- Laboratory of Pathophysiology, College of Pharmacy, Chungnam National University, 99 Daehak-ro, Yuseong-Gu, Daejeon, 34134, South Korea.
| |
Collapse
|
12
|
Hamilton S, Terentyeva R, Martin B, Perger F, Li J, Stepanov A, Bonilla IM, Knollmann BC, Radwański PB, Györke S, Belevych AE, Terentyev D. Increased RyR2 activity is exacerbated by calcium leak-induced mitochondrial ROS. Basic Res Cardiol 2020; 115:38. [PMID: 32444920 PMCID: PMC7244455 DOI: 10.1007/s00395-020-0797-z] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 05/07/2020] [Indexed: 11/29/2022]
Abstract
Cardiac disease is associated with deleterious emission of mitochondrial reactive oxygen species (mito-ROS), as well as enhanced oxidation and activity of the sarcoplasmic reticulum (SR) Ca2+ release channel, the ryanodine receptor (RyR2). The transfer of Ca2+ from the SR via RyR2 to mitochondria is thought to play a key role in matching increased metabolic demand during stress. In this study, we investigated whether augmented RyR2 activity results in self-imposed exacerbation of SR Ca2+ leak, via altered SR-mitochondrial Ca2+ transfer and elevated mito-ROS emission. Fluorescent indicators and spatially restricted genetic ROS probes revealed that both pharmacologically and genetically enhanced RyR2 activity, in ventricular myocytes from rats and catecholaminergic polymorphic ventricular tachycardia (CPVT) mice, respectively, resulted in increased ROS emission under β-adrenergic stimulation. Expression of mitochondrial Ca2+ probe mtRCamp1h revealed diminished net mitochondrial [Ca2+] with enhanced SR Ca2+ leak, accompanied by depolarization of the mitochondrial matrix. While this may serve as a protective mechanism to prevent mitochondrial Ca2+ overload, protection is not complete and enhanced mito-ROS emission resulted in oxidation of RyR2, further amplifying proarrhythmic SR Ca2+ release. Importantly, the effects of augmented RyR2 activity could be attenuated by mitochondrial ROS scavenging, and experiments with dominant-negative paralogs of the mitochondrial Ca2+ uniporter (MCU) supported the hypothesis that SR-mitochondria Ca2+ transfer is essential for the increase in mito-ROS. We conclude that in a process whereby leak begets leak, augmented RyR2 activity modulates mitochondrial Ca2+ handling, promoting mito-ROS emission and driving further channel activity in a proarrhythmic feedback cycle in the diseased heart.
Collapse
Affiliation(s)
- Shanna Hamilton
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Radmila Terentyeva
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Benjamin Martin
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Fruzsina Perger
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Jiaoni Li
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Andrei Stepanov
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.,Laboratory of Cell Pathology, Institute RAS, Saint Petersburg, Russia
| | - Ingrid M Bonilla
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Björn C Knollmann
- Division of Clinical Pharmacology, Vanderbilt University Medical School, Nashville, TN, 37232, USA
| | - Przemyslaw B Radwański
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.,Division of Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH, 43210, USA
| | - Sandor Györke
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Andriy E Belevych
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Dmitry Terentyev
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA. .,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.
| |
Collapse
|
13
|
Connell P, Word TA, Wehrens XHT. Targeting pathological leak of ryanodine receptors: preclinical progress and the potential impact on treatments for cardiac arrhythmias and heart failure. Expert Opin Ther Targets 2020; 24:25-36. [PMID: 31869254 DOI: 10.1080/14728222.2020.1708326] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Introduction: Type-2 ryanodine receptor (RyR2) located on the sarcoplasmic reticulum initiate systolic Ca2+ transients within cardiomyocytes. Proper functioning of RyR2 is therefore crucial to the timing and force generated by cardiomyocytes within a healthy heart. Improper intracellular Ca2+ handing secondary to RyR2 dysfunction is associated with a variety of cardiac pathologies including catecholaminergic polymorphic ventricular tachycardia (CPVT), atrial fibrillation (AF), and heart failure (HF). Thus, RyR2 and its associated accessory proteins provide promising drug targets to scientists developing therapeutics for a variety of cardiac pathologies.Areas covered: In this article, we review the role of RyR2 in a variety of cardiac pathologies. We performed a literature search utilizing PubMed and MEDLINE as well as reviewed registries of trials from clinicaltrials.gov from 2010 to 2019 for novel therapeutic approaches that address the cellular mechanisms underlying CPVT, AF, and HF by specifically targeting defective RyR2 channels.Expert opinion: The negative impact of cardiac dysfunction on human health and medical economics are major motivating factors for establishing new and effective therapeutic approaches. Focusing on directly impacting the molecular mechanisms underlying defective Ca2+ handling by RyR2 in HF and arrhythmia has great potential to be translated into novel and innovative therapies.
Collapse
Affiliation(s)
- Patrick Connell
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA.,Departments of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Tarah A Word
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA.,Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA.,Departments of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA.,Medicine (Cardiology, Baylor College of Medicine, Houston, TX, USA.,Neuroscience, Baylor College of Medicine, Houston, TX, USA.,Center for Space Medicine, Baylor College of Medicine, Houston, TX, USA
| |
Collapse
|
14
|
Rosso C, Gisbertz S, Williams JD, Gemoets HPL, Debrouwer W, Pieber B, Kappe CO. An oscillatory plug flow photoreactor facilitates semi-heterogeneous dual nickel/carbon nitride photocatalytic C–N couplings. REACT CHEM ENG 2020. [DOI: 10.1039/d0re00036a] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Dual nickel/photocatalytic C–N couplings are performed with an organic heterogeneous photocatalyst, in an oscillatory plug flow reactor. Reaction was complete in 20 min residence time, enabling 2.7 g h−1 throughput and 10-fold catalyst recycling.
Collapse
Affiliation(s)
- Cristian Rosso
- Institute of Chemistry
- University of Graz
- 8010 Graz
- Austria
| | - Sebastian Gisbertz
- Department of Biomolecular Systems
- Max-Planck-Institute of Colloids and Interfaces
- 14476 Potsdam
- Germany
- Department of Chemistry and Biochemistry
| | - Jason D. Williams
- Institute of Chemistry
- University of Graz
- 8010 Graz
- Austria
- Center for Continuous Flow Synthesis and Processing (CCFLOW)
| | | | | | - Bartholomäus Pieber
- Department of Biomolecular Systems
- Max-Planck-Institute of Colloids and Interfaces
- 14476 Potsdam
- Germany
| | - C. Oliver Kappe
- Institute of Chemistry
- University of Graz
- 8010 Graz
- Austria
- Center for Continuous Flow Synthesis and Processing (CCFLOW)
| |
Collapse
|
15
|
Pan Y, Luo Z, Xu X, Zhao H, Han J, Xu L, Fan Q, Xiao J. Ru‐Catalyzed Deoxygenative Transfer Hydrogenation of Amides to Amines with Formic Acid/Triethylamine. Adv Synth Catal 2019. [DOI: 10.1002/adsc.201900406] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Yixiao Pan
- Department of ChemistryRenmin University of China Beijing 100872 People's Republic of China
| | - Zhenli Luo
- Department of ChemistryRenmin University of China Beijing 100872 People's Republic of China
| | - Xin Xu
- Department of ChemistryRenmin University of China Beijing 100872 People's Republic of China
| | - Haoqiang Zhao
- Department of ChemistryRenmin University of China Beijing 100872 People's Republic of China
| | - Jiahong Han
- Department of ChemistryRenmin University of China Beijing 100872 People's Republic of China
| | - Lijin Xu
- Department of ChemistryRenmin University of China Beijing 100872 People's Republic of China
| | - Qinghua Fan
- Institute of ChemistryChinese Academy of Sciences Beijing 100190 People's Republic of China
| | - Jianliang Xiao
- Department of ChemistryUniversity of Liverpool Liverpool L69 7ZD United Kingdom
| |
Collapse
|
16
|
Pan Y, Luo Z, Han J, Xu X, Chen C, Zhao H, Xu L, Fan Q, Xiao J. B(C
6
F
5
)
3
‐Catalyzed Deoxygenative Reduction of Amides to Amines with Ammonia Borane. Adv Synth Catal 2019. [DOI: 10.1002/adsc.201801447] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Yixiao Pan
- Department of ChemistryRenmin University of China Beijing 100872 People's Republic of China
| | - Zhenli Luo
- Department of ChemistryRenmin University of China Beijing 100872 People's Republic of China
| | - Jiahong Han
- Department of ChemistryRenmin University of China Beijing 100872 People's Republic of China
| | - Xin Xu
- Department of ChemistryRenmin University of China Beijing 100872 People's Republic of China
| | - Changjun Chen
- Department of ChemistryRenmin University of China Beijing 100872 People's Republic of China
| | - Haoqiang Zhao
- Department of ChemistryRenmin University of China Beijing 100872 People's Republic of China
| | - Lijin Xu
- Department of ChemistryRenmin University of China Beijing 100872 People's Republic of China
| | - Qinghua Fan
- Institute of ChemistryChinese Academy of Sciences Beijing 100190 People's Republic of China
| | - Jianliang Xiao
- Department of ChemistryUniversity of Liverpool Liverpool L69 7ZD United Kingdom
| |
Collapse
|
17
|
Zou H, Chen G, Zhou S. Design, synthesis and biological activity evaluation of benzoate compounds as local anesthetics. RSC Adv 2019; 9:6627-6635. [PMID: 35518493 PMCID: PMC9060930 DOI: 10.1039/c9ra00476a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Accepted: 02/11/2019] [Indexed: 01/22/2023] Open
Abstract
Tetracaine and pramocaine were used as the lead compounds to design benzoate compounds. The combination principle was used to design the target molecule, and the target molecule was modified by bioisostere formation and modification with alkyl groups. In this research, a total of 16 compounds were designed and synthesized. In the process of synthesis, we selected a route with high total yields, mild conditions and simple operation. Three steps were used in the synthesis of the new target compounds, namely, alkylation, esterification and alkylation. The newly designed target compounds were evaluated via surface anesthesia, infiltration anesthesia, block anesthesia and acute toxicity tests. The results of biological activity experiments showed that compounds 4d, 4g, 4j, 4k, 4n, and 4o had a good local anesthetic effect, and the results of acute toxicity tests showed that the target compounds had low toxicity. Tetracaine and pramocaine were used as the lead compounds to design benzoate compounds.![]()
Collapse
Affiliation(s)
- Huiying Zou
- College of Chemistry and Chemical Engineering
- Hainan Normal University
- Haikou 571158
- China
- Key Laboratory of Tropical Medicinal Plant Chemistry of Ministry of Education
| | - Guangying Chen
- College of Chemistry and Chemical Engineering
- Hainan Normal University
- Haikou 571158
- China
- Key Laboratory of Tropical Medicinal Plant Chemistry of Ministry of Education
| | - Shiyang Zhou
- College of Chemistry and Chemical Engineering
- Hainan Normal University
- Haikou 571158
- China
- Key Laboratory of Tropical Medicinal Plant Chemistry of Ministry of Education
| |
Collapse
|
18
|
Zhou S, Huang G, Chen G. Synthesis and biological activities of local anesthetics. RSC Adv 2019; 9:41173-41191. [PMID: 35540039 PMCID: PMC9076432 DOI: 10.1039/c9ra09287k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 11/27/2019] [Indexed: 01/22/2023] Open
Abstract
Local anesthetics are mainly used in stomatology, ophthalmology, gynecology and surgery to temporarily relieve pain. Local anesthetics act on nerve endings or around nerve trunks, and are combined with specific sodium ion (Na+) channel sites on the nerve membrane. They can affect the membrane potential by reducing Na+ passage through sodium ion channels, thus blocking the generation and conduction of nerve impulses, reversibly blocking the generation and conduction of sensory nerve impulses. Local anesthetics are used for convenience in local surgical operations and treatments. Herein, we mainly review the research progress on local anesthetics and discuss the important aspects of design, synthesis and biological activity of various new compounds. Local anesthetics are mainly used in stomatology, ophthalmology, gynecology and surgery to temporarily relieve pain.![]()
Collapse
Affiliation(s)
- Shiyang Zhou
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education
- College of Chemistry and Chemical Engineering
- Hainan Normal University
- Haikou 571158
- China
| | - Gangliang Huang
- Active Carbohydrate Research Institute
- Chongqing Key Laboratory of Green Synthesis and Application
- College of Chemistry
- Chongqing Normal University
- Chongqing 401331
| | - Guangying Chen
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education
- College of Chemistry and Chemical Engineering
- Hainan Normal University
- Haikou 571158
- China
| |
Collapse
|
19
|
Liu B, Walton SD, Ho HT, Belevych AE, Tikunova SB, Bonilla I, Shettigar V, Knollmann BC, Priori SG, Volpe P, Radwański PB, Davis JP, Györke S. Gene Transfer of Engineered Calmodulin Alleviates Ventricular Arrhythmias in a Calsequestrin-Associated Mouse Model of Catecholaminergic Polymorphic Ventricular Tachycardia. J Am Heart Assoc 2018; 7:JAHA.117.008155. [PMID: 29720499 PMCID: PMC6015318 DOI: 10.1161/jaha.117.008155] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Background Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a familial arrhythmogenic syndrome characterized by sudden death. There are several genetic forms of CPVT associated with mutations in genes encoding the cardiac ryanodine receptor (RyR2) and its auxiliary proteins including calsequestrin (CASQ2) and calmodulin (CaM). It has been suggested that impairment of the ability of RyR2 to stay closed (ie, refractory) during diastole may be a common mechanism for these diseases. Here, we explore the possibility of engineering CaM variants that normalize abbreviated RyR2 refractoriness for subsequent viral‐mediated delivery to alleviate arrhythmias in non–CaM‐related CPVT. Methods and Results To that end, we have designed a CaM protein (GSH‐M37Q; dubbed as therapeutic CaM or T‐CaM) that exhibited a slowed N‐terminal Ca dissociation rate and prolonged RyR2 refractoriness in permeabilized myocytes derived from CPVT mice carrying the CASQ2 mutation R33Q. This T‐CaM was introduced to the heart of R33Q mice through recombinant adeno‐associated viral vector serotype 9. Eight weeks postinfection, we performed confocal microscopy to assess Ca handling and recorded surface ECGs to assess susceptibility to arrhythmias in vivo. During catecholamine stimulation with isoproterenol, T‐CaM reduced isoproterenol‐promoted diastolic Ca waves in isolated CPVT cardiomyocytes. Importantly, T‐CaM exposure abolished ventricular tachycardia in CPVT mice challenged with catecholamines. Conclusions Our results suggest that gene transfer of T‐CaM by adeno‐associated viral vector serotype 9 improves myocyte Ca handling and alleviates arrhythmias in a calsequestrin‐associated CPVT model, thus supporting the potential of a CaM‐based antiarrhythmic approach as a therapeutic avenue for genetically distinct forms of CPVT.
Collapse
Affiliation(s)
- Bin Liu
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH.,Department of Biological Sciences, Mississippi State University, Starkville, MI
| | - Shane D Walton
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Hsiang-Ting Ho
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Andriy E Belevych
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Svetlana B Tikunova
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Ingrid Bonilla
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Vikram Shettigar
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Bjorn C Knollmann
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Vanderbilt, TN
| | - Silvia G Priori
- Division of Cardiology and Molecular Cardiology, Maugeri Foundation-University of Pavia, Italy
| | - Pompeo Volpe
- Department of Biomedical Sciences, University of Padova, Italy
| | - Przemysław B Radwański
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Jonathan P Davis
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Sándor Györke
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| |
Collapse
|
20
|
Kim JC, Wang J, Son MJ, Woo SH. Shear stress enhances Ca 2+ sparks through Nox2-dependent mitochondrial reactive oxygen species generation in rat ventricular myocytes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:1121-1131. [PMID: 28213332 DOI: 10.1016/j.bbamcr.2017.02.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 02/01/2017] [Accepted: 02/12/2017] [Indexed: 02/06/2023]
Abstract
Shear stress enhances diastolic and systolic Ca2+ concentration in ventricular myocytes. Here, using confocal Ca2+ imaging in rat ventricular myocytes, we assessed the effects of shear stress (~16dyn/cm2) on the frequency of spontaneous Ca2+ sparks and explored the mechanism underlying shear-mediated Ca2+ spark regulation. The frequency of Ca2+ sparks was immediately increased by shear stress (by ~80%), and increased further (by ~150%) during prolonged exposure (20s). The 2-D size and duration of individual sparks were increased by shear stimulation. Inhibition of nitric oxide synthase (NOS) only partially attenuated the prolonged shear-mediated enhancement in spark frequency. Pretreatment with antioxidants significantly attenuated the short- and long-term effects of shear on spark frequency. Microtubule or nicotinamide adenine dinucleotide phosphate oxidase 2 (Nox2) inhibition abolished the immediate shear-induced increase in spark frequency and suppressed the effects of prolonged exposure to shear stress by ~70%. Scavenging of mitochondrial reactive oxygen species (ROS) and mitochondrial uncoupling also abolished the effect of short-term shear on spark occurrence, and markedly reduced (by ~80%) the effects of prolonged shear. Mitochondrial ROS levels increased under shear; this was eliminated by blocking Nox2. Sarcoplasmic reticulum Ca2+ content was increased only by prolonged shear. Our data suggest that shear stress enhances ventricular spark frequency mainly via ROS generated from mitochondria through Nox2, and that NOS and higher sarcoplasmic reticulum Ca2+ concentrations may also contribute to the enhancement of Ca2+ sparks under shear stress. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech.
Collapse
Affiliation(s)
- Joon-Chul Kim
- Laboratory of Physiology, College of Pharmacy, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764, South Korea
| | - Jun Wang
- Laboratory of Physiology, College of Pharmacy, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764, South Korea
| | - Min-Jeong Son
- Laboratory of Physiology, College of Pharmacy, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764, South Korea
| | - Sun-Hee Woo
- Laboratory of Physiology, College of Pharmacy, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764, South Korea.
| |
Collapse
|
21
|
Li N, Wang Q, Sibrian-Vazquez M, Klipp RC, Reynolds JO, Word TA, Scott L, Salama G, Strongin RM, Abramson JJ, Wehrens XHT. Treatment of catecholaminergic polymorphic ventricular tachycardia in mice using novel RyR2-modifying drugs. Int J Cardiol 2017; 227:668-673. [PMID: 27838126 PMCID: PMC5164850 DOI: 10.1016/j.ijcard.2016.10.078] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 10/28/2016] [Indexed: 12/26/2022]
Abstract
RATIONALE Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a potentially lethal arrhythmic disorder caused by mutations in the type-2 ryanodine receptor (RyR2). Mutant RyR2 cause abnormal Ca2+ leak from the sarcoplasmic reticulum (SR), which is associated with the development of arrhythmias. OBJECTIVE To determine whether derivatives of tetracaine, a local anesthetic drug with known RyR2 inhibiting action, could prevent CPVT induction by suppression of RyR2-mediated SR Ca2+ leak. METHODS AND RESULTS Confocal microscopy was used to assess the effects of tetracaine and 9 derivatives (EL1-EL9) on spontaneous Ca2+ sparks in ventricular myocytes isolated from RyR2-R176Q/+ mice with CPVT. Whereas each derivative suppressed the Ca2+ spark frequency, derivative EL9 was most effective at the screening dose of 500nmol/L. At this high dose, the Ca2+ transient amplitude was not affected in myocytes from WT or R176Q/+ mice. The IC50 of EL9 was determined to be 13nmol/L, which is about 400× time lower than known RyR2 stabilizer K201. EL9 prevented the induction of ventricular tachycardia observed in placebo-treated R176Q/+ mice, without affecting heart rate or cardiac contractility. CONCLUSIONS Tetracaine derivatives represent a novel class of RyR2 stabilizing drugs that could be used for the treatment of the potentially fatal disorder catecholaminergic polymorphic ventricular tachycardia.
Collapse
Affiliation(s)
- Na Li
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Qiongling Wang
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Robert C Klipp
- Department of Physics, Portland State University, Portland, OR 97207, USA
| | - Julia O Reynolds
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Tarah A Word
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Larry Scott
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Guy Salama
- Department of Medicine, Heart and Vascular Institute, University of Pittsburgh, Pittsburg, PA 15260, USA
| | - Robert M Strongin
- Department of Chemistry, Portland State University, Portland, OR 97207, USA
| | | | - Xander H T Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Medicine (Cardiology), Baylor College of Medicine, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA.
| |
Collapse
|
22
|
Madineh H, Amani S, Kabiri M, Karimi B. Evaluation of the anesthetic effect of nasal mucosa with tetracaine 0.5% on hemodynamic changes and postoperative pain of septoplasty: A randomized controlled trial. J Adv Pharm Technol Res 2017; 8:116-119. [PMID: 29184841 PMCID: PMC5680617 DOI: 10.4103/japtr.japtr_8_17] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
The nasal septum repair surgery is the dangerous operations that any stimulation of this area causes a large change in the rhythm of the heartbeat and blood pressure. This study aimed to determine the effects of tetracaine 0.5% on changes in heartbeat and heart rhythm, hemodynamic changes during surgery, intraoperative bleeding, and pain after septoplasty surgery. The irregular double-blind clinical trial registry of clinical trials Iran with the code number (IRCT: 20150526625N8) in the first half of 2013 on 86 patients in Kashani hospital of Shahrekord. Having selected and matched the patients were divided into two groups. Case group was dropped tetracaine 0.5% in each of the nasal cavity 15 min before the beginning of the operation. The control group was dropped distilled water 15 min preoperation in each of the nasal cavity. The surgery lasted about 30-60 min. Clinical symptoms were evaluated after anesthetic induction as well as pain using the visual analog scale after the operation, in the recovery room. The collected data were analyzed using SPSS version software 17 through independent t-test, Chi-square, and repeated measures variance analysis. Postoperative pain intensity in the experimental group compared to the control group was significantly lower than the control group (P < 0.05); however, blood pressure and heart rate during anesthesia, there was no difference between groups (P > 0.05). Based on the findings, intake of tetracaine drop 0.5% has no impact on some hemodynamic changes during septoplasty operation. However, compared with the control group, pain was significantly reduced.
Collapse
Affiliation(s)
- Hossein Madineh
- Department of Anesthesiology, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Soroush Amani
- Department of Otolaryngology, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Majid Kabiri
- Department of Anesthesiology, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Behnam Karimi
- Department of Nurse of Anaesthesia of Kashani Hospital, Shahrekord University of Medical Sciences, Shahrekord, Iran
| |
Collapse
|
23
|
Sato D, Shannon TR, Bers DM. Sarcoplasmic Reticulum Structure and Functional Properties that Promote Long-Lasting Calcium Sparks. Biophys J 2016; 110:382-390. [PMID: 26789761 DOI: 10.1016/j.bpj.2015.12.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 12/07/2015] [Accepted: 12/09/2015] [Indexed: 11/18/2022] Open
Abstract
Calcium (Ca) sparks are the fundamental sarcoplasmic reticulum (SR) Ca release events in cardiac myocytes, and they have a typical duration of 20-40 ms. However, when a fraction of ryanodine receptors (RyRs) are blocked by tetracaine or ruthenium red, Ca sparks lasting hundreds of milliseconds have been observed experimentally. The fundamental mechanism underlying these extremely prolonged Ca sparks is not understood. In this study, we use a physiologically detailed mathematical model of subcellular Ca cycling to examine how Ca spark duration is influenced by the number of functional RyRs in a junctional cluster (which is reduced by tetracaine or ruthenium red) and other SR Ca handling properties. One RyR cluster contains a few to several hundred RyRs, and we use a four-state Markov RyR gating model. Each RyR opens stochastically and is regulated by cytosolic and luminal Ca. We varied the number of functional RyRs in the single cluster, diffusion within the SR network, diffusion between network and junctional SR, cytosolic Ca diffusion, SERCA uptake activity, and RyR open probability. For long-lasting Ca release events, opening events within the cluster must occur continuously because the typical open time of the RyR is only a few milliseconds. We found the following: 1) if the number of RyRs is too small, it is difficult to maintain consecutive openings and stochastic attrition terminates the release; 2) if the number of RyRs is too large, the depletion of Ca from the junctional SR terminates the release; and 3) very long release events require relatively small-sized RyR clusters (reducing flux as seen experimentally with tetracaine) and sufficiently rapid intra-SR Ca diffusion, such that local junctional intra-SR [Ca] can be maintained by intra-SR diffusion and overall SR Ca reuptake.
Collapse
Affiliation(s)
- Daisuke Sato
- Department of Pharmacology, University of California, Davis, Davis, California.
| | - Thomas R Shannon
- Molecular Biophysics and Physiology, Rush University, Chicago, Illinois
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis, Davis, California
| |
Collapse
|
24
|
Yuan ML, Xie JH, Zhou QL. Boron Lewis Acid Promoted Ruthenium-Catalyzed Hydrogenation of Amides: An Efficient Approach to Secondary Amines. ChemCatChem 2016. [DOI: 10.1002/cctc.201600635] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ming-Lei Yuan
- State Key Laboratory and Institute of Elemento-organic Chemistry; Nankai University; 94 Weijin Road Tianjin P.R. China
| | - Jian-Hua Xie
- State Key Laboratory and Institute of Elemento-organic Chemistry; Nankai University; 94 Weijin Road Tianjin P.R. China
| | - Qi-Lin Zhou
- State Key Laboratory and Institute of Elemento-organic Chemistry; Nankai University; 94 Weijin Road Tianjin P.R. China
- Collaborative Innovation Center of Chemical Science and Engineering; Nankai University; 94 Weijin Road Tianjin P.R. China
| |
Collapse
|
25
|
Song Z, Karma A, Weiss JN, Qu Z. Long-Lasting Sparks: Multi-Metastability and Release Competition in the Calcium Release Unit Network. PLoS Comput Biol 2016; 12:e1004671. [PMID: 26730593 PMCID: PMC4701461 DOI: 10.1371/journal.pcbi.1004671] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 11/23/2015] [Indexed: 11/20/2022] Open
Abstract
Calcium (Ca) sparks are elementary events of biological Ca signaling. A normal Ca spark has a brief duration in the range of 10 to 100 ms, but long-lasting sparks with durations of several hundred milliseconds to seconds are also widely observed. Experiments have shown that the transition from normal to long-lasting sparks can occur when ryanodine receptor (RyR) open probability is either increased or decreased. Here, we demonstrate theoretically and computationally that long-lasting sparks emerge as a collective dynamical behavior of the network of diffusively coupled Ca release units (CRUs). We show that normal sparks occur when the CRU network is monostable and excitable, while long-lasting sparks occur when the network dynamics possesses multiple metastable attractors, each attractor corresponding to a different spatial firing pattern of sparks. We further highlight the mechanisms and conditions that produce long-lasting sparks, demonstrating the existence of an optimal range of RyR open probability favoring long-lasting sparks. We find that when CRU firings are sparse and sarcoplasmic reticulum (SR) Ca load is high, increasing RyR open probability promotes long-lasting sparks by potentiating Ca-induced Ca release (CICR). In contrast, when CICR is already strong enough to produce frequent firings, decreasing RyR open probability counter-intuitively promotes long-lasting sparks by decreasing spark frequency. The decrease in spark frequency promotes intra-SR Ca diffusion from neighboring non-firing CRUs to the firing CRUs, which helps to maintain the local SR Ca concentration of the firing CRUs above a critical level to sustain firing. In this setting, decreasing RyR open probability further suppresses long-lasting sparks by weakening CICR. Since a long-lasting spark terminates via the Kramers’ escape process over a potential barrier, its duration exhibits an exponential distribution determined by the barrier height and noise strength, which is modulated differently by different ways of altering the Ca release flux strength. Calcium (Ca) sparks, resulting from Ca-induced Ca release, are elementary events of biological Ca signaling. Sparks are normally brief, but long-lasting sparks have been widely observed experimentally under various conditions. The underlying mechanisms of spark duration or termination and the corresponding determinants remain a topic of debate. In this study, we demonstrate theoretically and computationally that normal brief sparks are excitable transients, while long-lasting sparks are multiple metastable states emerging in the diffusively coupled Ca release unit network, as a result of cooperativity and release competition among the Ca release units. Termination of a long-lasting spark is a Kramers’ escape process over a potential barrier, and the spark duration is the first-passage time, exhibiting an exponential distribution.
Collapse
Affiliation(s)
- Zhen Song
- The UCLA Cardiovascular Research Laboratory, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Alain Karma
- Department of Physics, Northeastern University, Boston, Massachusetts, United States of America
| | - James N. Weiss
- The UCLA Cardiovascular Research Laboratory, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Zhilin Qu
- The UCLA Cardiovascular Research Laboratory, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
- * E-mail:
| |
Collapse
|
26
|
Liu B, Ho HT, Brunello L, Unudurthi SD, Lou Q, Belevych AE, Qian L, Kim DH, Cho C, Janssen PML, Hund TJ, Knollmann BC, Kranias EG, Györke S. Ablation of HRC alleviates cardiac arrhythmia and improves abnormal Ca handling in CASQ2 knockout mice prone to CPVT. Cardiovasc Res 2015; 108:299-311. [PMID: 26410369 DOI: 10.1093/cvr/cvv222] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 09/17/2015] [Indexed: 01/02/2023] Open
Abstract
AIMS Cardiac calsequestrin (CASQ2) and histidine-rich Ca-binding protein (HRC) are sarcoplasmic reticulum (SR) Ca-binding proteins that regulate SR Ca release in mammalian heart. Deletion of either CASQ2 or HRC results in relatively mild phenotypes characterized by preserved cardiac structure and function, although CASQ2 knockout (KO), or Cnull, shows increased arrhythmia burden under conditions of catecholaminergic stress. We hypothesized that given the apparent overlap of functions of CASQ2 and HRC, simultaneous ablation of both would deteriorate the cardiac phenotype compared with the single knockouts. METHODS AND RESULTS In contrast to this expectation, double knockout (DKO) mice lacking both CASQ2 and HRC exhibited normal cardiac ejection fraction and ultrastructure. Moreover, the predisposition to catecholamine-dependent arrhythmia that characterizes the Cnull phenotype was alleviated in the DKO mice. At the myocyte level, DKO mice displayed Ca transients of normal amplitude; additionally, the frequency of spontaneous Ca waves and sparks in the presence of isoproterenol were decreased markedly compared with Cnull. Furthermore, restitution of SR Ca release was slowed in DKO myocytes compared with Cnull cells. CONCLUSION Our results suggest that rather than being functionally redundant, CASQ2 and HRC modulate cardiac ryanodine receptor-mediated (RyR2) Ca release in an opposing manner. In particular, while CASQ2 stabilizes RyR2 rendering it refractory in the diastolic phase, HRC enhances RyR2 activity facilitating RyR2 recovery from refractoriness.
Collapse
Affiliation(s)
- Bin Liu
- Department of Physiology and Cell Biology, College of Medicine, and Davis Heart and Lung Research Institute, The Ohio State University, 473 W. 12th Avenue, Columbus, OH 43210, USA
| | - Hsiang-Ting Ho
- Department of Physiology and Cell Biology, College of Medicine, and Davis Heart and Lung Research Institute, The Ohio State University, 473 W. 12th Avenue, Columbus, OH 43210, USA
| | - Lucia Brunello
- Department of Physiology and Cell Biology, College of Medicine, and Davis Heart and Lung Research Institute, The Ohio State University, 473 W. 12th Avenue, Columbus, OH 43210, USA
| | - Sathya D Unudurthi
- Department of Physiology and Cell Biology, College of Medicine, and Davis Heart and Lung Research Institute, The Ohio State University, 473 W. 12th Avenue, Columbus, OH 43210, USA
| | - Qing Lou
- Department of Physiology and Cell Biology, College of Medicine, and Davis Heart and Lung Research Institute, The Ohio State University, 473 W. 12th Avenue, Columbus, OH 43210, USA
| | - Andriy E Belevych
- Department of Physiology and Cell Biology, College of Medicine, and Davis Heart and Lung Research Institute, The Ohio State University, 473 W. 12th Avenue, Columbus, OH 43210, USA
| | - Lan Qian
- Department of Physiology and Cell Biology, College of Medicine, and Davis Heart and Lung Research Institute, The Ohio State University, 473 W. 12th Avenue, Columbus, OH 43210, USA
| | - Do Han Kim
- School of Life Sciences and Systems Biology Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju, Korea
| | - Chunghee Cho
- School of Life Sciences and Systems Biology Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju, Korea
| | - Paul M L Janssen
- Department of Physiology and Cell Biology, College of Medicine, and Davis Heart and Lung Research Institute, The Ohio State University, 473 W. 12th Avenue, Columbus, OH 43210, USA
| | - Thomas J Hund
- Department of Physiology and Cell Biology, College of Medicine, and Davis Heart and Lung Research Institute, The Ohio State University, 473 W. 12th Avenue, Columbus, OH 43210, USA
| | - Bjorn C Knollmann
- Division of Clinical Pharmacology, Vanderbilt University Medical School, Nashville, TN 37232, USA
| | - Evangelia G Kranias
- Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Sándor Györke
- Department of Physiology and Cell Biology, College of Medicine, and Davis Heart and Lung Research Institute, The Ohio State University, 473 W. 12th Avenue, Columbus, OH 43210, USA
| |
Collapse
|
27
|
Tamashiro H, Yoshino M. Involvement of plasma membrane Ca2+ channels, IP3 receptors, and ryanodine receptors in the generation of spontaneous rhythmic contractions of the cricket lateral oviduct. JOURNAL OF INSECT PHYSIOLOGY 2014; 71:97-104. [PMID: 25450564 DOI: 10.1016/j.jinsphys.2014.10.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 10/07/2014] [Accepted: 10/09/2014] [Indexed: 06/04/2023]
Abstract
In the present study, the isolated cricket (Gryllus bimaculatus) lateral oviduct exhibited spontaneous rhythmic contractions (SRCs) with a frequency of 0.29±0.009 Hz (n=43) and an amplitude of 14.6±1.25 mg (n=29). SRCs completely disappeared following removal of extracellular Ca2+ using a solution containing 5mM EGTA. Application of the non-specific Ca2+ channel blockers Co2+, Ni2+, and Cd2+ also decreased both the frequency and amplitude of SRCs in dose-dependent manners, suggesting that Ca2+ entry through plasma membrane Ca2+ channels is essential for the generation of SRCs. Application of ryanodine (30 μM), which depletes intracellular Ca2+ by locking ryanodine receptor (RyR)-Ca2+ channels in an open state, gradually reduced the frequency and amplitude of SRCs. A RyR antagonist, tetracaine, reduced both the frequency and amplitude of SRCs, whereas a RyR activator, caffeine, increased the frequency of SRCs with a subsequent increase in basal tonus, indicating that RyRs are essential for generating SRCs. To further investigate the involvement of phospholipase C (PLC) and inositol 1,4,5-trisphosphate receptors (IP3Rs) in SRCs, we examined the effect of a PLC inhibitor, U73122, and an IP3R antagonist, 2-aminoethoxydiphenyl borate (2-APB), on SRCs. Separately, U73122 (10 μM) and 2-APB (30-50 μM) both significantly reduced the amplitude of SRCs with little effect on their frequency, further indicating that the PLC/IP3R signaling pathway is fundamental to the modulation of the amplitude of SRCs. A hypotonic-induced increase in the frequency and amplitude of SRCs and a hypertonic-induced decrease in the frequency and amplitude of SRCs indicated that mechanical stretch of the lateral oviduct is involved in the generation of SRCs. The sarcoplasmic reticulum Ca2+-pump ATPase inhibitors thapsigargin and cyclopiazonic acid impaired or suppressed the relaxation phase of SRCs. Taken together, the present results indicate that Ca2+ influx through plasma membrane Ca2+ channels and Ca2+ release from RyRs play an essential role in pacing SRCs and that Ca2+ release from IP3Rs may play a role in modulating the amplitude of SRCs, probably via activation of PLC.
Collapse
Affiliation(s)
| | - Masami Yoshino
- Department of Biology, Tokyo Gakugei University, Tokyo 184-8501, Japan.
| |
Collapse
|
28
|
Fernandez-Fuente M, Terracciano CM, Martin-Duque P, Brown SC, Vassaux G, Piercy RJ. Calcium homeostasis in myogenic differentiation factor 1 (MyoD)-transformed, virally-transduced, skin-derived equine myotubes. PLoS One 2014; 9:e105971. [PMID: 25148524 PMCID: PMC4141859 DOI: 10.1371/journal.pone.0105971] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 07/30/2014] [Indexed: 11/19/2022] Open
Abstract
Dysfunctional skeletal muscle calcium homeostasis plays a central role in the pathophysiology of several human and animal skeletal muscle disorders, in particular, genetic disorders associated with ryanodine receptor 1 (RYR1) mutations, such as malignant hyperthermia, central core disease, multiminicore disease and certain centronuclear myopathies. In addition, aberrant skeletal muscle calcium handling is believed to play a pivotal role in the highly prevalent disorder of Thoroughbred racehorses, known as Recurrent Exertional Rhabdomyolysis. Traditionally, such defects were studied in human and equine subjects by examining the contractile responses of biopsied muscle strips exposed to caffeine, a potent RYR1 agonist. However, this test is not widely available and, due to its invasive nature, is potentially less suitable for valuable animals in training or in the human paediatric setting. Furthermore, increasingly, RYR1 gene polymorphisms (of unknown pathogenicity and significance) are being identified through next generation sequencing projects. Consequently, we have investigated a less invasive test that can be used to study calcium homeostasis in cultured, skin-derived fibroblasts that are converted to the muscle lineage by viral transduction with a MyoD (myogenic differentiation 1) transgene. Similar models have been utilised to examine calcium homeostasis in human patient cells, however, to date, there has been no detailed assessment of the cells’ calcium homeostasis, and in particular, the responses to agonists and antagonists of RYR1. Here we describe experiments conducted to assess calcium handling of the cells and examine responses to treatment with dantrolene, a drug commonly used for prophylaxis of recurrent exertional rhabdomyolysis in horses and malignant hyperthermia in humans.
Collapse
Affiliation(s)
- Marta Fernandez-Fuente
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Sciences and Services, Royal Veterinary College, London, United Kingdom
| | - Cesare M. Terracciano
- Laboratory of Cell Electrophysiology, Imperial College London, Myocardial Function, National Heart and Lung Institute, Hammersmith Hospital, London, United Kingdom
| | - Pilar Martin-Duque
- Universidad Francisco de Vitoria, Facultad de Ciencias Biosanitarias: Pozuelo de Alarcón (Madrid), Madrid, Spain
| | - Susan C. Brown
- Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom
| | - Georges Vassaux
- Laboratoire TIRO, UMRE 4320, iBEB, DSV, Commissariat a’ l’Energie Atomique, Nice, France
| | - Richard J. Piercy
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Sciences and Services, Royal Veterinary College, London, United Kingdom
- * E-mail:
| |
Collapse
|
29
|
Kim JC, Wang J, Son MJ, Cuong NM, Woo SH. Sensitization of cardiac Ca2+ release sites by protein kinase C signaling: evidence from action of murrayafoline A. Pflugers Arch 2014; 467:1607-1621. [DOI: 10.1007/s00424-014-1589-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 07/06/2014] [Accepted: 07/28/2014] [Indexed: 11/29/2022]
|
30
|
Wei JS, Jin ZB, Yin ZQ, Xie QM, Chen JQ, Li ZG, Tang HF. Effects of local anesthetics on contractions of pregnant and non-pregnant rat myometriumin vitro. ACTA ACUST UNITED AC 2014; 101:228-35. [DOI: 10.1556/aphysiol.101.2014.2.11] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
31
|
Liu B, Ho HT, Velez-Cortes F, Lou Q, Valdivia CR, Knollmann BC, Valdivia HH, Gyorke S. Genetic ablation of ryanodine receptor 2 phosphorylation at Ser-2808 aggravates Ca(2+)-dependent cardiomyopathy by exacerbating diastolic Ca2+ release. J Physiol 2014; 592:1957-73. [PMID: 24445321 DOI: 10.1113/jphysiol.2013.264689] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Phosphorylation of the cardiac ryanodine receptor (RyR2) by protein kinase A (PKA) at Ser-2808 is suggested to mediate the physiological 'fight or flight' response and contribute to heart failure by rendering the sarcoplasmic reticulum (SR) leaky for Ca(2+). In the present study, we examined the potential role of RyR2 phosphorylation at Ser-2808 in the progression of Ca(2+)-dependent cardiomyopathy (CCM) by using mice genetically modified to feature elevated SR Ca(2+) leak while expressing RyR2s that cannot be phosphorylated at this site (S2808A). Surprisingly, rather than alleviating the disease phenotype, constitutive dephosphorylation of Ser-2808 aggravated CCM as manifested by shortened survival, deteriorated in vivo cardiac function, exacerbated SR Ca(2+) leak and mitochondrial injury. Notably, the deteriorations of cardiac function, myocyte Ca(2+) handling, and mitochondria integrity were consistently worse in mice with heterozygous ablation of Ser-2808 than in mice with complete ablation. Wild-type (WT) and CCM myocytes expressing unmutated RyR2s exhibited a high level of baseline phosphorylation at Ser-2808. Exposure of these CCM cells to protein phosphatase 1 caused a transitory increase in Ca(2+) leak attributable to partial dephosphorylation of RyR2 tetramers at Ser-2808 from more fully phosphorylated state. Thus, exacerbated Ca(2+) leak through partially dephosphorylated RyR2s accounts for the prevalence of the disease phenotype in the heterozygous S2808A CCM mice. These results do not support the importance of RyR2 hyperphosphorylation in Ca(2+)-dependent heart disease, and rather suggest roles for the opposite process, the RyR2 dephosphorylation at this residue in physiological and pathophysiological Ca(2+) signalling.
Collapse
Affiliation(s)
- Bin Liu
- Department of Physiology and Cell Biology, 507 Davis Heart & Lung Research Institute (office), 473 W. 12th Avenue, Columbus, OH 43210, USA.
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Santiago DJ, Ríos E, Shannon TR. Isoproterenol increases the fraction of spark-dependent RyR-mediated leak in ventricular myocytes. Biophys J 2013; 104:976-85. [PMID: 23473480 DOI: 10.1016/j.bpj.2013.01.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 12/21/2012] [Accepted: 01/17/2013] [Indexed: 10/27/2022] Open
Abstract
Recent research suggests that the diastolic ryanodine-receptor-mediated release of Ca(2+) (J(leak)) from the sarcoplasmic reticulum of ventricular myocytes occurs in spark and nonspark forms. Further information about the role(s) of these release manifestations is scarce, however. This study addresses whether the fraction of spark-mediated J(leak) increases due to β-adrenergic stimulation. Confocal microscopy was used to simultaneously image Ca(2+) sparks and quantify J(leak) in intact rabbit myocytes, either in the absence or in the presence of 125 nM isoproterenol. It was found that isoproterenol treatment shifts the spark-frequency-J(leak) relationship toward an increased sensitivity to a [Ca(2+)] trigger. In agreement, a small but significant increase in spark width was found for cells with matched baseline [Ca(2+)] and total SR [Ca(2+)]. The reconstruction of release fluxes, when applied to the average sparks from those selected cells, yielded a wider release source in the isoproterenol event, indicating the recruitment of peripheral ryanodine receptors. Overall, the results presented here indicate that β-adrenergic stimulation increases the spark-dependent fraction of J(leak). Working together, the increased Ca(2+) sensitivity and the greater spark width found during isoproterenol treatment may increase the probability of Ca(2+) wave generation.
Collapse
Affiliation(s)
- Demetrio J Santiago
- Department of Molecular Biophysics & Physiology, Rush University, Chicago, Illinois, USA
| | | | | |
Collapse
|
33
|
Permeabilization of cell membrane for delivery of nano-objects to cellular sub-domains. Methods Mol Biol 2013; 991:57-63. [PMID: 23546659 DOI: 10.1007/978-1-62703-336-7_7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Delivery of nano-objects to specific cellular sub-domains is a challenging but intriguing task. There are two major barriers on the way of a nano-object to its intracellular target: (1) the cell membrane and (2) the intracellular barriers. The former is a common issue for all nanomedicine and a matter of very intense research. The latter is the primary problem for targeted delivery of nano-objects to specific cellular sub-domains and can be studied more easily using permeabilized cells. Membrane permeabilization for nanomedical research requires (1) perforation of the outer membrane, (2) development of a solution that will keep cellular sub-domains in the functional state, and (3) modification of the perimembrane cytoskeleton. We developed a very successful model of saponin membrane permeabilization of cardiomyocytes. This allowed us to deliver particles up to 20 nm in size to perinuclear and perimitochondrial space. Here we describe the method.
Collapse
|
34
|
Tencerová B, Zahradníková A, Gaburjáková J, Gaburjáková M. Luminal Ca2+ controls activation of the cardiac ryanodine receptor by ATP. ACTA ACUST UNITED AC 2012; 140:93-108. [PMID: 22851674 PMCID: PMC3409101 DOI: 10.1085/jgp.201110708] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The synergic effect of luminal Ca2+, cytosolic Ca2+, and cytosolic adenosine triphosphate (ATP) on activation of cardiac ryanodine receptor (RYR2) channels was examined in planar lipid bilayers. The dose–response of RYR2 gating activity to ATP was characterized at a diastolic cytosolic Ca2+ concentration of 100 nM over a range of luminal Ca2+ concentrations and, vice versa, at a diastolic luminal Ca2+ concentration of 1 mM over a range of cytosolic Ca2+ concentrations. Low level of luminal Ca2+ (1 mM) significantly increased the affinity of the RYR2 channel for ATP but without substantial activation of the channel. Higher levels of luminal Ca2+ (8–53 mM) markedly amplified the effects of ATP on the RYR2 activity by selectively increasing the maximal RYR2 activation by ATP, without affecting the affinity of the channel to ATP. Near-diastolic cytosolic Ca2+ levels (<500 nM) greatly amplified the effects of luminal Ca2+. Fractional inhibition by cytosolic Mg2+ was not affected by luminal Ca2+. In models, the effects of luminal and cytosolic Ca2+ could be explained by modulation of the allosteric effect of ATP on the RYR2 channel. Our results suggest that luminal Ca2+ ions potentiate the RYR2 gating activity in the presence of ATP predominantly by binding to a luminal site with an apparent affinity in the millimolar range, over which local luminal Ca2+ likely varies in cardiac myocytes.
Collapse
Affiliation(s)
- Barbora Tencerová
- Institute of Molecular Physiology and Genetics, Centre of Excellence for Cardiovascular Research, Slovak Academy of Sciences, 833 34 Bratislava, Slovak Republic
| | | | | | | |
Collapse
|
35
|
Liu N, Napolitano C, Venetucci LA, Priori SG. Flecainide and antiarrhythmic effects in a mouse model of catecholaminergic polymorphic ventricular tachycardia. Trends Cardiovasc Med 2012; 22:35-9. [PMID: 22867967 DOI: 10.1016/j.tcm.2012.06.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Recent studies have shown that flecainide may be an effective therapy to prevent life-threatening arrhythmias in patients with catecholaminergic polymorphic ventricular tachycardia. Several hypotheses have been advanced to explain the antiarrhythmic mechanism of flecainide, including Na(+) channel blockade and a direct inhibitory action on the ryanodine receptor. In this article, we review the current literature on the topic and summarize the elements of the existing debate.
Collapse
Affiliation(s)
- Nian Liu
- Cardiovascular Genetic Program, The Leon H. Charney Division of Cardiology, New York University School of Medicine, New York, NY 10016, USA
| | | | | | | |
Collapse
|
36
|
Thomas NL, Williams AJ. Pharmacology of ryanodine receptors and Ca2+-induced Ca2+ release. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/wmts.34] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
37
|
Sarchahi AA, Bozorgi H. Effect of tetracaine on intraocular pressure in normal and hypertensive rabbit eyes. J Ophthalmic Vis Res 2012; 7:29-33. [PMID: 22737384 PMCID: PMC3381104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 10/01/2011] [Indexed: 11/30/2022] Open
Abstract
PURPOSE To evaluate the effect of tetracaine on intraocular pressure (IOP) in normal and hypertensive rabbit eyes. METHODS The study was conducted on 12 healthy rabbits as controls and 6 healthy rabbits in which an experimental model of ocular hypertension (OHT) was induced by administration of 70 mL/kg of tap water through an orogastric tube. One drop of tetracaine was instilled in the left eye while a drop of normal saline (placebo) was applied to the right eye of the control group. IOP was measured before and 0, 5, 10, 15, 20, 25, 30, 35 and 40 minutes after drop administration in this group. The OHT group also received one drop of tetracaine and normal saline in the left eyes and right eyes respectively, immediately after water loading; the instillation of drops was repeated after 55 minutes. IOP was measured before and 0, 5, 10, 15, 20, 25, 30, 35, 40, 55, 70, 85, 100 and 115 minutes after water loading in this group. RESULTS Tetracaine treated eyes in both groups (ocular hypertensive and normal controls) demonstrated significant IOP reduction at time zero (immediately after drop instillation) which was sustained up to 20 minutes, as compared to placebo treated eyes (P<0.05). In ocular hypertensive rabbits, repeat instillation of tetracaine significantly reduced IOP at 55 minutes up to 30 minutes thereafter. CONCLUSION Topical tetracaine can reduce IOP; this fact should be considered in experiments evaluating IOP reducing agents.
Collapse
Affiliation(s)
- Ali Asghar Sarchahi
- Correspondence to: Ali Asghar Sarchahi, DVM, PhD. Associate Professor, Department of Clinical Studies, School of Veterinary Medicine, Shiraz University, Shiraz, Iran; Tel: +98 711 2286950, Fax: +98 711 2286940; e-mail:
| | | |
Collapse
|
38
|
Turan B, Vassort G. Ryanodine receptor: a new therapeutic target to control diabetic cardiomyopathy. Antioxid Redox Signal 2011; 15:1847-61. [PMID: 21091075 DOI: 10.1089/ars.2010.3725] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Diabetes mellitus is a major risk factor for cardiovascular complications. Intracellular Ca(2+) release plays an important role in the regulation of muscle contraction. Sarcoplasmic reticulum Ca(2+) release is controlled by dedicated molecular machinery, composed of a complex of cardiac ryanodine receptors (RyR2s). Acquired and genetic defects in this complex result in a spectrum of abnormal Ca(2+) release phenotypes in heart. Cardiovascular dysfunction is a leading cause for mortality of diabetic individuals due, in part, to a specific cardiomyopathy, and to altered vascular reactivity. Cardiovascular complications result from multiple parameters, including glucotoxicity, lipotoxicity, fibrosis, and mitochondrial uncoupling. In diabetic subjects, oxidative stress arises from an imbalance between production of reactive oxygen and nitrogen species and capability of the system to readily detoxify reactive intermediates. To date, the etiology underlying diabetes-induced reductions in myocyte and cardiac contractility remains incompletely understood. However, numerous studies, including work from our laboratory, suggest that these defects stem in part from perturbation in intracellular Ca(2+) cycling. Since the RyR2s are one of the well-characterized redox-sensitive ion channels in heart, this article summarizes recent findings on redox regulation of cardiac Ca(2+) transport systems and discusses contributions of redox regulation to pathological cardiac function in diabetes.
Collapse
Affiliation(s)
- Belma Turan
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey .
| | | |
Collapse
|
39
|
Laver DR, van Helden DF. Three independent mechanisms contribute to tetracaine inhibition of cardiac calcium release channels. J Mol Cell Cardiol 2011; 51:357-69. [DOI: 10.1016/j.yjmcc.2011.05.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 04/26/2011] [Accepted: 05/11/2011] [Indexed: 11/27/2022]
|
40
|
Bode EF, Briston SJ, Overend CL, O'Neill SC, Trafford AW, Eisner DA. Changes of SERCA activity have only modest effects on sarcoplasmic reticulum Ca2+ content in rat ventricular myocytes. J Physiol 2011; 589:4723-9. [PMID: 21825024 DOI: 10.1113/jphysiol.2011.211052] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Changes of the activity of the sarco-endoplasmic reticulum Ca(2+)-ATPase (SERCA) affect the amplitude of the systolic Ca(2+) transient and thence cardiac contractility. This is thought to be due to alterations of SR Ca(2+) content. Recent work on mice in which the expression of SERCA is decreased found that a large reduction of SERCA expression resulted in a proportionately much smaller decrease of SR Ca(2+) content. The aim of the current work was to investigate the quantitative nature of the dependence of both the amplitude of the systolic Ca(2+) transient and SR Ca(2+) content on SERCA activity during acute partial inhibition of SERCA. Experiments were performed on rat ventricular myocytes. Brief application of thapsigargin (1 μm) resulted in a decrease of SERCA activity as measured from the rate of decay of the systolic Ca(2+) transient. This was accompanied by a decrease in the amplitude of the systolic Ca(2+) transient which was linearly related to that of SERCA activity. However, the fractional decrease in the SR Ca(2+) content was much less than that of SERCA activity. On average SR Ca(2+) content was proportional to SERCA activity raised to the 0.38 ± 0.07 power. This shallow dependence of SR content on SERCA activity arises because Ca(2+) release is a steep function of SR Ca(2+) content. In contrast SR Ca(2+) content was increased 4.59 ± 0.40 (n = 8)-fold by decreasing ryanodine receptor opening with tetracaine (1 mm). Therefore a modest decrease of SR Ca(2+) content results in a proportionately larger fall of Ca(2+) release from the SR which can balance a larger initiating decrease of SERCA. In conclusion, the shallow dependence of SR Ca(2+) content on SERCA activity is expected for a system in which small changes of SR Ca(2+) content produce larger effects on the amplitude of the systolic Ca(2+) transient.
Collapse
Affiliation(s)
- E F Bode
- Unit of Cardiac Physiology, University of Manchester, 46 Grafton Street, Manchester, UK.
| | | | | | | | | | | |
Collapse
|
41
|
Two candidates at the heart of dysfunction: The ryanodine receptor and calcium/calmodulin protein kinase II as potential targets for therapeutic intervention—An in vivo perspective. Pharmacol Ther 2011; 131:204-20. [DOI: 10.1016/j.pharmthera.2011.02.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 02/17/2011] [Indexed: 11/19/2022]
|
42
|
Ho HT, Stevens SCW, Terentyeva R, Carnes CA, Terentyev D, Györke S. Arrhythmogenic adverse effects of cardiac glycosides are mediated by redox modification of ryanodine receptors. J Physiol 2011; 589:4697-708. [PMID: 21807619 DOI: 10.1113/jphysiol.2011.210005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The therapeutic use of cardiac glycosides (CGs), agents commonly used in treating heart failure (HF), is limited by arrhythmic toxicity. The adverse effects of CGs have been attributed to excessive accumulation of intracellular Ca(2+) resulting from inhibition of Na(+)/K(+)-ATPase ion transport activity. However, CGs are also known to increase intracellular reactive oxygen species (ROS), which could contribute to arrhythmogenesis through redox modification of cardiac ryanodine receptors (RyR2s). Here we sought to determine whether modification of RyR2s by ROS contributes to CG-dependent arrhythmogenesis and examine the relevant sources of ROS. In isolated rat ventricular myocytes, the CG digitoxin (DGT) increased the incidence of arrhythmogenic spontaneous Ca(2+) waves, decreased the sarcoplasmic reticulum (SR) Ca(2+) load, and increased both ROS and RyR2 thiol oxidation. Additionally, pretreatment with DGT increased spark frequency in permeabilized myocytes. These effects on Ca(2+) waves and sparks were prevented by the antioxidant N-(2-mercaptopropionyl) glycine (MPG). The CG-dependent increases in ROS, RyR2 oxidation and arrhythmogenic propensity were reversed by inhibitors of NADPH oxidase, mitochondrial ATP-dependent K(+) channels (mito-K(ATP)) or permeability transition pore (PTP), but not by inhibition of xanthine oxidase. These results suggest that the arrhythmogenic adverse effects of CGs involve alterations in RyR2 function caused by oxidative changes in the channel structure by ROS. These CG-dependent effects probably involve release of ROS from mitochondria possibly mediated by NADPH oxidase.
Collapse
Affiliation(s)
- Hsiang-Ting Ho
- Davis Heart and Lung Research Institute, The Ohio State University Medical Centre, 473 W. 12th Avenue, Columbus, OH 43210, USA
| | | | | | | | | | | |
Collapse
|
43
|
Galimberti ES, Knollmann BC. Efficacy and potency of class I antiarrhythmic drugs for suppression of Ca2+ waves in permeabilized myocytes lacking calsequestrin. J Mol Cell Cardiol 2011; 51:760-8. [PMID: 21798265 DOI: 10.1016/j.yjmcc.2011.07.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 05/31/2011] [Accepted: 07/05/2011] [Indexed: 02/08/2023]
Abstract
Ca(2+) waves can trigger ventricular arrhythmias such as catecholaminergic-polymorphic ventricular tachycardia (CPVT). Drugs that prevent Ca(2+) waves may have antiarrhythmic properties. Here, we use permeabilized ventricular myocytes from a CPVT mouse model lacking calsequestrin (casq2) to screen all clinically available class I antiarrhythmic drugs and selected other antiarrhythmic agents for activity against Ca(2+) waves. Casq2-/- myocytes were imaged in line-scan mode and the following Ca(2+) wave parameters analyzed: wave incidence, amplitude, frequency, and propagation speed. IC(50) (potency) and maximum inhibition (efficacy) were calculated for each drug. Drugs fell into 3 distinct categories. Category 1 drugs (flecainide and R-propafenone) suppressed wave parameters with the highest potency (IC(50)<10 μM) and efficacy (>50% maximum wave inhibition). Category 2 drugs (encainide, quinidine, lidocaine, and verapamil) had intermediate potency (IC(50) 20-40 μM) and efficacy (20-40% maximum wave inhibition). Category 3 drugs (procainamide, disopyramide, mexiletine, cibenzoline, and ranolazine) had no significant effects on Ca(2+) waves at the highest concentration tested (100 μM). Propafenone was stereoselective, with R-propafenone suppressing waves more potently than S-propafenone (IC(50): R-propafenone 2 ± 0.2 μM vs. S-propafenone 54 ± 18 μM). Both flecainide and R-propafenone decreased Ca(2+) spark mass and converted propagated Ca(2+) waves into non-propagated wavelets and frequent sparks, suggesting that reduction in spark mass, not spark frequency, was responsible for wave suppression. Among all class I antiarrhythmic drugs, flecainide and R-propafenone inhibit Ca(2+) waves with the highest potency and efficacy. Permeabilized casq2-/- myocytes are a simple in-vitro assay for finding drugs with activity against Ca(2+) waves. This article is part of a Special Issue entitled 'Possible Editorial'.
Collapse
Affiliation(s)
- Eleonora Savio Galimberti
- Division of Clinical Pharmacology and Oates Institute for Experimental Therapeutics, Vanderbilt University School of Medicine, Nashville, USA
| | | |
Collapse
|
44
|
Kojima A, Kitagawa H, Omatsu-Kanbe M, Matsuura H, Nosaka S. Ca2+ paradox injury mediated through TRPC channels in mouse ventricular myocytes. Br J Pharmacol 2011; 161:1734-50. [PMID: 20718730 DOI: 10.1111/j.1476-5381.2010.00986.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND AND PURPOSE The Ca(2+) paradox is an important phenomenon associated with Ca(2+) overload-mediated cellular injury in myocardium. The present study was undertaken to elucidate molecular and cellular mechanisms for the development of the Ca(2+) paradox. EXPERIMENTAL APPROACH Fluorescence imaging was performed on fluo-3 loaded quiescent mouse ventricular myocytes using confocal laser scanning microscope. KEY RESULTS The Ca(2+) paradox was readily evoked by restoration of the extracellular Ca(2+) following 10-20 min of nominally Ca(2+)-free superfusion. The Ca(2+) paradox was significantly reduced by blockers of transient receptor potential canonical (TRPC) channels (2-aminoethoxydiphenyl borate, Gd(3+), La(3+)) and anti-TRPC1 antibody. The sarcoplasmic reticulum (SR) Ca(2+) content, assessed by caffeine application, gradually declined during Ca(2+)-free superfusion, which was further accelerated by metabolic inhibition. Block of SR Ca(2+) leak by tetracaine prevented Ca(2+) paradox. The Na(+) /Ca(2+) exchange (NCX) blocker KB-R7943 significantly inhibited Ca(2+) paradox when applied throughout superfusion period, but had little effect when added for a period of 3 min before and during Ca(2+) restoration. The SR Ca(2+) content was better preserved during Ca(2+) depletion by KB-R7943. Immunocytochemistry confirmed the expression of TRPC1, in addition to TRPC3 and TRPC4, in mouse ventricular myocytes. CONCLUSIONS AND IMPLICATIONS These results provide evidence that (i) the Ca(2+) paradox is primarily mediated by Ca(2+) entry through TRPC (probably TRPC1) channels that are presumably activated by SR Ca(2+) depletion; and (ii) reverse mode NCX contributes little to the Ca(2+) paradox, whereas inhibition of NCX during Ca(2+) depletion improves SR Ca(2+) loading, and is associated with reduced incidence of Ca(2+) paradox in mouse ventricular myocytes.
Collapse
Affiliation(s)
- Akiko Kojima
- Department of Anesthesiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | | | | | | | | |
Collapse
|
45
|
Zima AV, Bovo E, Bers DM, Blatter LA. Ca²+ spark-dependent and -independent sarcoplasmic reticulum Ca²+ leak in normal and failing rabbit ventricular myocytes. J Physiol 2010; 588:4743-57. [PMID: 20962003 DOI: 10.1113/jphysiol.2010.197913] [Citation(s) in RCA: 145] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Sarcoplasmic reticulum (SR) Ca²(+) leak is an important component of cardiac Ca²(+) signalling. Together with the SR Ca²(+)-ATPase (SERCA)-mediated Ca²(+) uptake, diastolic Ca²(+) leak determines SR Ca²(+) load and, therefore, the amplitude of Ca²(+) transients that initiate contraction. Spontaneous Ca²(+) sparks are thought to play a major role in SR Ca²(+) leak. In this study, we determined the quantitative contribution of sparks to SR Ca²(+) leak and tested the hypothesis that non-spark mediated Ca²(+) release also contributes to SR Ca²(+) leak. We simultaneously measured spark properties and intra-SR free Ca²(+) ([Ca²(+)](SR)) after complete inhibition of SERCA with thapsigargin in permeabilized rabbit ventricular myocytes. When [Ca²(+)](SR) declined to 279 ± 10 μm, spark activity ceased completely; however SR Ca²(+) leak continued, albeit at a slower rate. Analysis of sparks and [Ca²(+)](SR) revealed, that SR Ca²(+) leak increased as a function of [Ca²(+)](SR), with a particularly steep increase at higher [Ca²(+)](SR) ( >600 μm) where sparks become a major pathway of SR Ca²(+) leak. At low [Ca²(+)](SR) (< 300 μm), however, Ca²(+) leak occurred mostly as non-spark-mediated leak. Sensitization of ryanodine receptors (RyRs) with low doses of caffeine increased spark frequency and SR Ca²(+) leak. Complete inhibition of RyR abolished sparks and significantly decreased SR Ca²(+) leak, but did not prevent it entirely, suggesting the existence of RyR-independent Ca²(+) leak. Finally, we found that RyR-mediated Ca²(+) leak was enhanced in myocytes from failing rabbit hearts. These results show that RyRs are the main, but not sole contributor to SR Ca²(+) leak. RyR-mediated leak occurs in part as Ca²(+) sparks, but there is clearly RyR-mediated but Ca²(+) sparks independent leak.
Collapse
Affiliation(s)
- Aleksey V Zima
- Department of Cell and Molecular Physiology, Loyola University Chicago, Stritch School of Medicine, Maywood, IL 60153, USA.
| | | | | | | |
Collapse
|
46
|
MacQuaide N, Ramay HR, Sobie EA, Smith GL. Differential sensitivity of Ca²+ wave and Ca²+ spark events to ruthenium red in isolated permeabilised rabbit cardiomyocytes. J Physiol 2010; 588:4731-42. [PMID: 20921197 DOI: 10.1113/jphysiol.2010.193375] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Spontaneous Ca²(+) waves in cardiac muscle cells are thought to arise from the sequential firing of local Ca²(+) sparks via a fire-diffuse-fire mechanism. This study compares the ability of the ryanodine receptor (RyR) blocker ruthenium red (RuR) to inhibit these two types of Ca²(+) release in permeabilised rabbit ventricular cardiomyocytes. Perfusing with 600 nm Ca²(+) (50 μm EGTA) caused regular spontaneous Ca²(+) waves that were imaged with the fluorescence from Fluo-5F using a laser-scanning confocal microscope. Addition of 4 μm RuR caused complete inhibition of Ca²(+) waves in 50% of cardiomyocytes by 2 min and in 100% by 4 min. Separate experiments used 350 μm EGTA (600 nm Ca²(+)) to limit Ca²(+) diffusion but allow the underlying Ca(2+) sparks to be imaged. The time course of RuR-induced inhibition did not match that of waves. After 2 min of RuR, none of the characteristics of the Ca²(+) sparks were altered, and after 4 min Ca²(+) spark frequency was reduced ∼40%; no sparks could be detected after 10 min. Measurements of Ca(2+) within the SR lumen using Fluo-5N showed an increase in intra-SR Ca²(+) during the initial 2-4 min of perfusion with RuR in both wave and spark conditions. Computational modelling suggests that the sensitivity of Ca²(+) waves to RuR block depends on the number of RyRs per cluster. Therefore inhibition of Ca²(+) waves without affecting Ca²(+) sparks may be explained by block of small, non-spark producing clusters of RyRs that are important to the process of Ca²(+) wave propagation.
Collapse
Affiliation(s)
- N MacQuaide
- Institute of Biomedical and Life Sciences, West Medical Building, University of Glasgow, Glasgow G12 8QQ, UK.
| | | | | | | |
Collapse
|
47
|
Hartman JM, Sobie EA, Smith GD. Spontaneous Ca2+ sparks and Ca2+ homeostasis in a minimal model of permeabilized ventricular myocytes. Am J Physiol Heart Circ Physiol 2010; 299:H1996-2008. [PMID: 20852058 DOI: 10.1152/ajpheart.00293.2010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Many issues remain unresolved concerning how local, subcellular Ca(2+) signals interact with bulk cellular concentrations to maintain homeostasis in health and disease. To aid in the interpretation of data obtained in quiescent ventricular myocytes, we present here a minimal whole cell model that accounts for both localized (subcellular) and global (cellular) aspects of Ca(2+) signaling. Using a minimal formulation of the distribution of local [Ca(2+)] associated with a large number of Ca(2+)-release sites, the model simulates both random spontaneous Ca(2+) sparks and the changes in myoplasmic and sarcoplasmic reticulum (SR) [Ca(2+)] that result from the balance between stochastic release and reuptake into the SR. Ca(2+)-release sites are composed of clusters of two-state ryanodine receptors (RyRs) that exhibit activation by local cytosolic [Ca(2+)] but no inactivation or regulation by luminal Ca(2+). Decreasing RyR open probability in the model causes a decrease in aggregate release flux and an increase in SR [Ca(2+)], regardless of whether RyR inhibition is mediated by a decrease in RyR open dwell time or an increase in RyR closed dwell time. The same balance of stochastic release and reuptake can be achieved, however, by either high-frequency/short-duration or low-frequency/long-duration Ca(2+) sparks. The results are well correlated with recent experimental observations using pharmacological RyR inhibitors and clarify those aspects of the release-reuptake balance that are inherent to the coupling between local and global Ca(2+) signals and those aspects that depend on molecular-level details. The model of Ca(2+) sparks and homeostasis presented here can be a useful tool for understanding changes in cardiac Ca(2+ )release resulting from drugs, mutations, or acquired diseases.
Collapse
Affiliation(s)
- Jana M Hartman
- Department of Applied Science, The College of William and Mary, Williamsburg, Virginia 23187, USA
| | | | | |
Collapse
|
48
|
Santiago DJ, Curran JW, Bers DM, Lederer WJ, Stern MD, Ríos E, Shannon TR. Ca sparks do not explain all ryanodine receptor-mediated SR Ca leak in mouse ventricular myocytes. Biophys J 2010; 98:2111-20. [PMID: 20483318 DOI: 10.1016/j.bpj.2010.01.042] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 01/04/2010] [Accepted: 01/19/2010] [Indexed: 11/17/2022] Open
Abstract
Diastolic Ca leak from the sarcoplasmic reticulum (SR) of ventricular myocytes reduces the SR Ca content, stabilizing the activity of the SR Ca release channel ryanodine receptor for the next beat. SR Ca leak has been visualized globally using whole-cell fluorescence, or locally using confocal microscopy, but never both ways. When using confocal microscopy, leak is imaged as "Ca sparks," which are fluorescent objects generated by the local reaction-diffusion of released Ca and cytosolic indicator. Here, we used confocal microscopy and simultaneously measured the global ryanodine-receptor-mediated leak rate (J(leak)) and Ca sparks in intact mouse ventricular myocytes. We found that spark frequency and J(leak) are correlated, as expected if both are manifestations of a common phenomenon. However, we also found that sparks explain approximately half of J(leak). Our strategy unmasks the presence of a subresolution (i.e., nonspark) release of potential physiological relevance.
Collapse
Affiliation(s)
- Demetrio J Santiago
- Department of Molecular Biophysics & Physiology, Rush University, Chicago, Illinois, USA
| | | | | | | | | | | | | |
Collapse
|
49
|
Janowski E, Berríos M, Cleemann L, Morad M. Developmental aspects of cardiac Ca(2+) signaling: interplay between RyR- and IP(3)R-gated Ca(2+) stores. Am J Physiol Heart Circ Physiol 2010; 298:H1939-50. [PMID: 20304819 DOI: 10.1152/ajpheart.00607.2009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The dominant mode of intracellular Ca(2+) release in adult mammalian heart is gated by ryanodine receptors (RyRs), but it is less clear whether inositol 1,4,5-trisphosphate (IP(3))-gated Ca(2+) release channels (IP(3)Rs), which are important during embryogenesis, play a significant role during early postnatal development. To address this question, we measured confocal two-dimensional Ca(2+) dependent fluorescence images in acutely isolated neonatal (days 1 to 2) and juvenile (days 8-10) rat cardiomyocytes, either voltage-clamped or permeabilized, where rapid exchange of solution could be used to selectively activate the two types of Ca(2+) release channel. Targeting RyRs with caffeine produced large and rapid Ca(2+) signals throughout the cells. Application of ATP and endothelin-1 to voltage-clamped, or IP(3) to permeabilized, cells produced smaller and slower Ca(2+) signals that were most prominent in subsarcolemmal regions and were suppressed by either the IP(3)R-blocker 2-aminoethoxydiphenylborate or replacement of the biologically active form of IP(3) with its L-stereoisomer. Such IP(3)R-gated Ca(2+) releases were amplified by Ca(2+)-induced Ca(2+) release (CICR) via RyRs since they were also reduced by compounds that block the RyRs (tetracaine) or deplete the Ca(2+) pools they gate (caffeine, ryanodine). Spatial analysis revealed both subsarcolemmal and perinuclear origins for the IP(3)-mediated Ca(2+) release events RyR- and IP(3)R-gated Ca(2+) signals had larger magnitudes in juvenile than in neonatal cardiomyocytes. Ca(2+) signaling was generally quite similar in atrial and ventricular cardiomyocytes but showed divergent development of IP(3)-mediated regulation in juveniles. Our data suggest that an intermediate stage of Ca(2+) signaling may be present in developing cardiomyocytes, where, in addition to RyR-gated Ca(2+) pools, IP(3)-gated Ca(2+) release is sufficiently large in magnitude and duration to trigger or contribute to activation of CICR and cardiac contraction.
Collapse
|
50
|
Abstract
The sarcoplasmic reticulum (SR) of smooth muscles presents many intriguing facets and questions concerning its roles, especially as these change with development, disease, and modulation of physiological activity. The SR's function was originally perceived to be synthetic and then that of a Ca store for the contractile proteins, acting as a Ca amplification mechanism as it does in striated muscles. Gradually, as investigators have struggled to find a convincing role for Ca-induced Ca release in many smooth muscles, a role in controlling excitability has emerged. This is the Ca spark/spontaneous transient outward current coupling mechanism which reduces excitability and limits contraction. Release of SR Ca occurs in response to inositol 1,4,5-trisphosphate, Ca, and nicotinic acid adenine dinucleotide phosphate, and depletion of SR Ca can initiate Ca entry, the mechanism of which is being investigated but seems to involve Stim and Orai as found in nonexcitable cells. The contribution of the elemental Ca signals from the SR, sparks and puffs, to global Ca signals, i.e., Ca waves and oscillations, is becoming clearer but is far from established. The dynamics of SR Ca release and uptake mechanisms are reviewed along with the control of luminal Ca. We review the growing list of the SR's functions that still includes Ca storage, contraction, and relaxation but has been expanded to encompass Ca homeostasis, generating local and global Ca signals, and contributing to cellular microdomains and signaling in other organelles, including mitochondria, lysosomes, and the nucleus. For an integrated approach, a review of aspects of the SR in health and disease and during development and aging are also included. While the sheer versatility of smooth muscle makes it foolish to have a "one model fits all" approach to this subject, we have tried to synthesize conclusions wherever possible.
Collapse
Affiliation(s)
- Susan Wray
- Department of Physiology, School of Biomedical Sciences, University of Liverpool, Liverpool, Merseyside L69 3BX, United Kingdom.
| | | |
Collapse
|