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Li N, Shi R, Ye Y, Zhang Y, Zhang Y, Wang Z, Gu Y, Yin Y, Chen D, Tang J. Aging-induced down-regulation of Pka/Bkca pathway in rat cerebral arteries. Physiol Res 2022. [DOI: 10.33549/physiolres.934944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The incidence of cerebrovascular diseases increases significantly with aging. This study aimed to test the hypothesis that aging may influence the protein kinase A (PKA)-dependent vasodilation via RyR/BKCa pathway in the middle cerebral arteries (MCA). Male Sprague-Dawley rats were randomly divided into control (4-6 month-old) and aged (24-month-old) groups. The functions of MCA and ion channel activities in smooth muscle cells were examined using myograph system and patch-clamp. Aging decreased the isoproterenol/forskolin-induced relaxation in the MCA. Large-conductance Ca2+-activated-K+ (BKCa) channel inhibitor, iberiotoxin, significantly attenuated the forskolin-induced vasodilatation and hyperpolarization in the young group, but not in the aged group. The amplitude and frequency of spontaneous transient outward currents (STOCs) were significantly decreased in the aged group. Single channel recording revealed that the mean open time of BKCa channels were decreased, while an increased mean closed time of BKCa channels were found in the aged group. The Ca2+/voltage sensitivity of the channels was decreased accompanied by reduced BKCa α and β1-subunit, the expression of RyR2, PKA-Cα and PKA-Cβ subunits were also declined in the aged group. Aging induced down-regulation of PKA/BKCa pathway in cerebral artery in rats. The results provides new information on further understanding in cerebrovascular diseases resulted from age-related cerebral vascular dysfunction.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - J Tang
- Institute for Fetology, First Hospital of Soochow University, Suzhou, Jiangsu 215006, P. R. China. E-mail:
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2
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LI N, SHI R, YE Y, ZHANG Y, ZHANG Y, WANG Z, GU Y, YIN Y, CHEN D, TANG J. Aging-Induced Down-Regulation of PKA/BKCa Pathway in Rat Cerebral Arteries. Physiol Res 2022; 71:811-823. [PMID: 36426887 PMCID: PMC9814987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The incidence of cerebrovascular diseases increases significantly with aging. This study aimed to test the hypothesis that aging may influence the protein kinase A (PKA)-dependent vasodilation via RyR/BKCa pathway in the middle cerebral arteries (MCA). Male Sprague-Dawley rats were randomly divided into control (4-6 month-old) and aged (24-month-old) groups. The functions of MCA and ion channel activities in smooth muscle cells were examined using myograph system and patch-clamp. Aging decreased the isoproterenol/forskolin-induced relaxation in the MCA. Large-conductance Ca(2+)-activated-K(+) (BKCa) channel inhibitor, iberiotoxin, significantly attenuated the forskolin-induced vasodilatation and hyperpolarization in the young group, but not in the aged group. The amplitude and frequency of spontaneous transient outward currents (STOCs) were significantly decreased in the aged group. Single channel recording revealed that the mean open time of BKCa channels were decreased, while an increased mean closed time of BKCa channels were found in the aged group. The Ca(2+)/voltage sensitivity of the channels was decreased accompanied by reduced BKCa alpha and beta1-subunit, the expression of RyR2, PKA-Calpha and PKA-Cbeta subunits were also declined in the aged group. Aging induced down-regulation of PKA/BKCa pathway in cerebral artery in rats. The results provides new information on further understanding in cerebrovascular diseases resulted from age-related cerebral vascular dysfunction.
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Affiliation(s)
- Na LI
- Perinatal Medicine Laboratory, Wuxi Maternity and Child Health Care Hospital, Wuxi, Jiangsu, China
| | - Ruixiu SHI
- Department of Gynaecology and Obstetrics, Wuhan Fourth Hospital, Wuhan, Hubei, China
| | - Yang YE
- Perinatal Medicine Laboratory, Wuxi Maternity and Child Health Care Hospital, Wuxi, Jiangsu, China
| | - Yingying ZHANG
- Perinatal Medicine Laboratory, Wuxi Maternity and Child Health Care Hospital, Wuxi, Jiangsu, China
| | - Yumeng ZHANG
- Institute for Fetology, First Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Zhizhi WANG
- Perinatal Medicine Laboratory, Wuxi Maternity and Child Health Care Hospital, Wuxi, Jiangsu, China
| | - Ying GU
- Perinatal Medicine Laboratory, Wuxi Maternity and Child Health Care Hospital, Wuxi, Jiangsu, China
| | - Yongxiang YIN
- Perinatal Medicine Laboratory, Wuxi Maternity and Child Health Care Hospital, Wuxi, Jiangsu, China
| | - Daozhen CHEN
- Perinatal Medicine Laboratory, Wuxi Maternity and Child Health Care Hospital, Wuxi, Jiangsu, China
| | - Jiaqi TANG
- Institute for Fetology, First Hospital of Soochow University, Suzhou, Jiangsu, China
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King DR, Sedovy MW, Eaton X, Dunaway LS, Good ME, Isakson BE, Johnstone SR. Cell-To-Cell Communication in the Resistance Vasculature. Compr Physiol 2022; 12:3833-3867. [PMID: 35959755 DOI: 10.1002/cphy.c210040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The arterial vasculature can be divided into large conduit arteries, intermediate contractile arteries, resistance arteries, arterioles, and capillaries. Resistance arteries and arterioles primarily function to control systemic blood pressure. The resistance arteries are composed of a layer of endothelial cells oriented parallel to the direction of blood flow, which are separated by a matrix layer termed the internal elastic lamina from several layers of smooth muscle cells oriented perpendicular to the direction of blood flow. Cells within the vessel walls communicate in a homocellular and heterocellular fashion to govern luminal diameter, arterial resistance, and blood pressure. At rest, potassium currents govern the basal state of endothelial and smooth muscle cells. Multiple stimuli can elicit rises in intracellular calcium levels in either endothelial cells or smooth muscle cells, sourced from intracellular stores such as the endoplasmic reticulum or the extracellular space. In general, activation of endothelial cells results in the production of a vasodilatory signal, usually in the form of nitric oxide or endothelial-derived hyperpolarization. Conversely, activation of smooth muscle cells results in a vasoconstriction response through smooth muscle cell contraction. © 2022 American Physiological Society. Compr Physiol 12: 1-35, 2022.
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Affiliation(s)
- D Ryan King
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA
| | - Meghan W Sedovy
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA.,Translational Biology, Medicine, and Health Graduate Program, Virginia Tech, Blacksburg, Virginia, USA
| | - Xinyan Eaton
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA
| | - Luke S Dunaway
- Robert M. Berne Cardiovascular Research Centre, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Miranda E Good
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
| | - Brant E Isakson
- Robert M. Berne Cardiovascular Research Centre, University of Virginia School of Medicine, Charlottesville, Virginia, USA.,Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Scott R Johnstone
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA.,Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
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4
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Jackson WF. Calcium-Dependent Ion Channels and the Regulation of Arteriolar Myogenic Tone. Front Physiol 2021; 12:770450. [PMID: 34819877 PMCID: PMC8607693 DOI: 10.3389/fphys.2021.770450] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 10/11/2021] [Indexed: 11/25/2022] Open
Abstract
Arterioles in the peripheral microcirculation regulate blood flow to and within tissues and organs, control capillary blood pressure and microvascular fluid exchange, govern peripheral vascular resistance, and contribute to the regulation of blood pressure. These important microvessels display pressure-dependent myogenic tone, the steady state level of contractile activity of vascular smooth muscle cells (VSMCs) that sets resting arteriolar internal diameter such that arterioles can both dilate and constrict to meet the blood flow and pressure needs of the tissues and organs that they perfuse. This perspective will focus on the Ca2+-dependent ion channels in the plasma and endoplasmic reticulum membranes of arteriolar VSMCs and endothelial cells (ECs) that regulate arteriolar tone. In VSMCs, Ca2+-dependent negative feedback regulation of myogenic tone is mediated by Ca2+-activated K+ (BKCa) channels and also Ca2+-dependent inactivation of voltage-gated Ca2+ channels (VGCC). Transient receptor potential subfamily M, member 4 channels (TRPM4); Ca2+-activated Cl− channels (CaCCs; TMEM16A/ANO1), Ca2+-dependent inhibition of voltage-gated K+ (KV) and ATP-sensitive K+ (KATP) channels; and Ca2+-induced-Ca2+ release through inositol 1,4,5-trisphosphate receptors (IP3Rs) participate in Ca2+-dependent positive-feedback regulation of myogenic tone. Calcium release from VSMC ryanodine receptors (RyRs) provide negative-feedback through Ca2+-spark-mediated control of BKCa channel activity, or positive-feedback regulation in cooperation with IP3Rs or CaCCs. In some arterioles, VSMC RyRs are silent. In ECs, transient receptor potential vanilloid subfamily, member 4 (TRPV4) channels produce Ca2+ sparklets that activate IP3Rs and intermediate and small conductance Ca2+ activated K+ (IKCa and sKCa) channels causing membrane hyperpolarization that is conducted to overlying VSMCs producing endothelium-dependent hyperpolarization and vasodilation. Endothelial IP3Rs produce Ca2+ pulsars, Ca2+ wavelets, Ca2+ waves and increased global Ca2+ levels activating EC sKCa and IKCa channels and causing Ca2+-dependent production of endothelial vasodilator autacoids such as NO, prostaglandin I2 and epoxides of arachidonic acid that mediate negative-feedback regulation of myogenic tone. Thus, Ca2+-dependent ion channels importantly contribute to many aspects of the regulation of myogenic tone in arterioles in the microcirculation.
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Affiliation(s)
- William F Jackson
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, United States
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Alleyne J, Dopico AM. Alcohol Use Disorders and Their Harmful Effects on the Contractility of Skeletal, Cardiac and Smooth Muscles. ADVANCES IN DRUG AND ALCOHOL RESEARCH 2021; 1:10011. [PMID: 35169771 PMCID: PMC8843239 DOI: 10.3389/adar.2021.10011] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Alcohol misuse has deleterious effects on personal health, family, societal units, and global economies. Moreover, alcohol misuse usually leads to several diseases and conditions, including alcoholism, which is a chronic condition and a form of addiction. Alcohol misuse, whether as acute intoxication or alcoholism, adversely affects skeletal, cardiac and/or smooth muscle contraction. Ethanol (ethyl alcohol) is the main effector of alcohol-induced dysregulation of muscle contractility, regardless of alcoholic beverage type or the ethanol metabolite (with acetaldehyde being a notable exception). Ethanol, however, is a simple and "promiscuous" ligand that affects many targets to mediate a single biological effect. In this review, we firstly summarize the processes of excitation-contraction coupling and calcium homeostasis which are critical for the regulation of contractility in all muscle types. Secondly, we present the effects of acute and chronic alcohol exposure on the contractility of skeletal, cardiac, and vascular/ nonvascular smooth muscles. Distinctions are made between in vivo and in vitro experiments, intoxicating vs. sub-intoxicating ethanol levels, and human subjects vs. animal models. The differential effects of alcohol on biological sexes are also examined. Lastly, we show that alcohol-mediated disruption of muscle contractility, involves a wide variety of molecular players, including contractile proteins, their regulatory factors, membrane ion channels and pumps, and several signaling molecules. Clear identification of these molecular players constitutes a first step for a rationale design of pharmacotherapeutics to prevent, ameliorate and/or reverse the negative effects of alcohol on muscle contractility.
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Van S, Pal S, Garner BR, Steed K, Sridharan V, Mu S, Rusch NJ, Stolarz AJ. Dantrolene Prevents the Lymphostasis Caused by Doxorubicin in the Rat Mesenteric Circulation. Front Pharmacol 2021; 12:727526. [PMID: 34483938 PMCID: PMC8415554 DOI: 10.3389/fphar.2021.727526] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 08/05/2021] [Indexed: 11/29/2022] Open
Abstract
Background and Purpose: Doxorubicin (DOX) is a risk factor for arm lymphedema in breast cancer patients. We reported that DOX opens ryanodine receptors (RYRs) to enact "calcium leak," which disrupts the rhythmic contractions of lymph vessels (LVs) to attenuate lymph flow. Here, we evaluated whether dantrolene, a clinically available RYR1 subtype antagonist, prevents the detrimental effects of DOX on lymphatic function. Experimental Approach: Isolated rat mesenteric LVs were cannulated, pressurized (4-5 mm Hg) and equilibrated in physiological salt solution and Fura-2AM. Video microscopy recorded changes in diameter and Fura-2AM fluorescence tracked cytosolic free calcium ([Ca2+ i]). High-speed in vivo microscopy assessed mesenteric lymph flow in anesthetized rats. Flow cytometry evaluated RYR1 expression in freshly isolated mesenteric lymphatic muscle cells (LMCs). Key Results: DOX (10 μmol/L) increased resting [Ca2+ i] by 17.5 ± 3.7% in isolated LVs (n = 11). The rise in [Ca2+ i] was prevented by dantrolene (3 μmol/L; n = 10). A single rapid infusion of DOX (10 mg/kg i.v.) reduced positive volumetric lymph flow to 29.7 ± 10.8% (n = 7) of baseline in mesenteric LVs in vivo. In contrast, flow in LVs superfused with dantrolene (10 μmol/L) only decreased to 76.3 ± 14.0% (n = 7) of baseline in response to DOX infusion. Subsequently, expression of the RYR1 subtype protein as the presumed dantrolene binding site was confirm in isolated mesenteric LMCs by flow cytometry. Conclusion and Implications: We conclude that dantrolene attenuates the acute impairment of lymph flow by DOX and suggest that its prophylactic use in patients subjected to DOX chemotherapy may lower lymphedema risk.
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Affiliation(s)
- Serena Van
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Soumiya Pal
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Brittney R. Garner
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Kate Steed
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Vijayalakshmi Sridharan
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Shengyu Mu
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Nancy J. Rusch
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Amanda J. Stolarz
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, United States
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Román M, García L, Morales M, Crespo MJ. The combination of dantrolene and nimodipine effectively reduces 5-HT-induced vasospasms in diabetic rats. Sci Rep 2021; 11:9852. [PMID: 33972638 PMCID: PMC8110522 DOI: 10.1038/s41598-021-89338-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/23/2021] [Indexed: 02/07/2023] Open
Abstract
Diabetics have a higher risk of developing cerebral vasospasms (CVSP) after subarachnoid hemorrhagic stroke than non-diabetics. Serotonin (5-HT) is one of the key vasoconstrictors released in the hemorrhagic blood and an important contributor to the etiology of CVSP. The combination of the ryanodine receptor blocker dantrolene and the Ca2+ channel blocker nimodipine significantly reduces phenylephrine (PHE)-induced vascular contraction in both diabetic and nondiabetic rats, but the effectiveness of this drug combination in reducing 5-HT-induced contraction is unknown. Dose–response curves for the 5-HT-induced contraction (from 0.1 nM to 100 µM) were performed on aortic rings from diabetic and non-diabetic rats after a 30-min incubation period with dantrolene, nimodipine, and both drugs in combination. In diabetic rats, 10 μM of dantrolene alone failed to reduce 5-HT-induced maximal contraction (Emax), but 50 μM reduced this parameter by 34% (n = 7, p < 0.05). In non-diabetic rats, by contrast, dantrolene did not modify the vascular response to 5-HT. 50 nM of nimodipine alone, however, reduced this parameter by 57% in diabetic rats (n = 10, p < 0.05), and by 34% in non-diabetic rats (n = 10, p < 0.05). In addition, concomitant administration of dantrolene and nimodipine reduced vascular reactivity to a similar extent in both diabetic (~ 60% reduction, n = 10, p < 0.05) and non-diabetic rats (~ 70% reduction, n = 10, p < 0.05). Moreover, the combination of nimodipine with the higher concentration of dantrolene significantly increased the EC50 values for the 5-HT-induced contraction curves in both diabetics (from 10.31 ± 1.17 µM to 19.26 ± 2.82; n = 10, p < 0.05) and non-diabetic rats (5.93 ± 0.54 µM to 15.80 ± 3.24; n = 10, p < 0.05). These results suggest that simultaneous administration of dantrolene and nimodipine has a synergistic effect in reducing 5-HT-induced vascular contraction under both diabetic and non-diabetic conditions. If our findings with rats are applicable to humans, concomitant administration of these drugs may represent a promising alternative for the management of CVSP in both diabetics and non-diabetics.
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Affiliation(s)
- Marie Román
- Department of Physiology, University of Puerto Rico-School of Medicine, GPO Box 365067, San Juan, PR, 00936-5067, USA
| | - Laura García
- Department of Anesthesiology, University of Puerto Rico-School of Medicine, GPO Box 365067, San Juan, PR, 00936-5067, USA
| | - Myrna Morales
- Department of Anesthesiology, University of Puerto Rico-School of Medicine, GPO Box 365067, San Juan, PR, 00936-5067, USA
| | - María J Crespo
- Department of Physiology, University of Puerto Rico-School of Medicine, GPO Box 365067, San Juan, PR, 00936-5067, USA. .,Department of Anesthesiology, University of Puerto Rico-School of Medicine, GPO Box 365067, San Juan, PR, 00936-5067, USA.
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Li XQ, Zheng YM, Reyes-García J, Wang YX. Diversity of ryanodine receptor 1-mediated Ca 2+ signaling in systemic and pulmonary artery smooth muscle cells. Life Sci 2021; 270:119016. [PMID: 33515564 DOI: 10.1016/j.lfs.2021.119016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 12/26/2020] [Accepted: 01/03/2021] [Indexed: 11/26/2022]
Abstract
AIMS Ryanodine receptor-1 (RyR1) is essential for skeletal muscle cell functions. However, its roles in vascular smooth muscle cells (SMCs) are well recognized. This study aims to determine the potential physiological importance and difference in systemic and pulmonary artery SMCs (SASMCs and PASMCs). METHODS Local and global Ca2+ release were measured using a laser scanning confocal microscope and wide-field fluorescence microscope; membrane currents were recorded using a patch clamp recording; muscle contraction was determined using an organ bath system; RyR protein expression was assessed using immunofluorescence staining. Homozygous and heterozygous RyR1 gene knockout (RyR1-/- and RyR1+/-) mice were used to determine its specific functions. KEY FINDINGS Ca2+ sparks were more prominently decreased in RyR1-/- ASMCs than in PASMCs. Caffeine induced a smaller increase in [Ca2+]i in both RyR1+/+ and RyR1-/- ASMCs than in PASMCs. High K+ produced a reduced [Ca2+]i increase in RyR1-/- PASMCs and ASMCs as well as a reduced contraction in RyR1+/- pulmonary artery and aortic tissues. ATP elicited a smaller increase in [Ca2+]i in RyR1-/- ASMCs and PASMCs with a greater inhibition in ASMCs. Norepinephrine-elicited muscle contraction was reduced in RyR1+/- aortic and pulmonary arteries. IP3 dialysis-induced Ca2+ release was much smaller in RyR1+/- ASMCs and PASMCs. Hypoxia-induced large Ca2+ and contractile responses were inhibited in RyR1+/- PASMCs. However, hypoxic exposure did not evoke a notable increase in [Ca2+]i in ASMCs. SIGNIFICANCE Our findings for the first time provide clear genetic evidence for the functional importance and difference of RyR1 in systemic and pulmonary artery SMCs.
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Affiliation(s)
- Xiao-Qiang Li
- Albany Medical College, Department of Molecular & Cellular Physiology (MC-8), 47 New Scotland Avenue, Albany, NY 12208, United States of America
| | - Yun-Min Zheng
- Albany Medical College, Department of Molecular & Cellular Physiology (MC-8), 47 New Scotland Avenue, Albany, NY 12208, United States of America
| | - Jorge Reyes-García
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, CDMX, México
| | - Yong-Xiao Wang
- Albany Medical College, Department of Molecular & Cellular Physiology (MC-8), 47 New Scotland Avenue, Albany, NY 12208, United States of America.
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Evans AM. On a Magical Mystery Tour with 8-Bromo-Cyclic ADP-Ribose: From All-or-None Block to Nanojunctions and the Cell-Wide Web. Molecules 2020; 25:E4768. [PMID: 33081414 PMCID: PMC7587525 DOI: 10.3390/molecules25204768] [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: 08/25/2020] [Accepted: 09/08/2020] [Indexed: 11/16/2022] Open
Abstract
A plethora of cellular functions are controlled by calcium signals, that are greatly coordinated by calcium release from intracellular stores, the principal component of which is the sarco/endooplasmic reticulum (S/ER). In 1997 it was generally accepted that activation of various G protein-coupled receptors facilitated inositol-1,4,5-trisphosphate (IP3) production, activation of IP3 receptors and thus calcium release from S/ER. Adding to this, it was evident that S/ER resident ryanodine receptors (RyRs) could support two opposing cellular functions by delivering either highly localised calcium signals, such as calcium sparks, or by carrying propagating, global calcium waves. Coincidentally, it was reported that RyRs in mammalian cardiac myocytes might be regulated by a novel calcium mobilising messenger, cyclic adenosine diphosphate-ribose (cADPR), that had recently been discovered by HC Lee in sea urchin eggs. A reputedly selective and competitive cADPR antagonist, 8-bromo-cADPR, had been developed and was made available to us. We used 8-bromo-cADPR to further explore our observation that S/ER calcium release via RyRs could mediate two opposing functions, namely pulmonary artery dilation and constriction, in a manner seemingly independent of IP3Rs or calcium influx pathways. Importantly, the work of others had shown that, unlike skeletal and cardiac muscles, smooth muscles might express all three RyR subtypes. If this were the case in our experimental system and cADPR played a role, then 8-bromo-cADPR would surely block one of the opposing RyR-dependent functions identified, or the other, but certainly not both. The latter seemingly implausible scenario was confirmed. How could this be, do cells hold multiple, segregated SR stores that incorporate different RyR subtypes in receipt of spatially segregated signals carried by cADPR? The pharmacological profile of 8-bromo-cADPR action supported not only this, but also indicated that intracellular calcium signals were delivered across intracellular junctions formed by the S/ER. Not just one, at least two. This article retraces the steps along this journey, from the curious pharmacological profile of 8-bromo-cADPR to the discovery of the cell-wide web, a diverse network of cytoplasmic nanocourses demarcated by S/ER nanojunctions, which direct site-specific calcium flux and may thus coordinate the full panoply of cellular processes.
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Grants
- 01/A/S/07453 Biotechnology and Biological Sciences Research Council
- WT046374 , WT056423, WT070772, WT074434, WT081195AIA, WT212923, WT093147 Wellcome Trust
- PG/10/95/28657 British Heart Foundation
- FS/03/033/15432, FS/05/050, PG/05/128/19884, RG/12/14/29885, PG/10/95/28657 British Heart Foundation
- RG/12/14/29885 British Heart Foundation
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Affiliation(s)
- A Mark Evans
- Centre for Discovery Brain Sciences and Cardiovascular Science, Edinburgh Medical School, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK
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10
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Thakore P, Pritchard HAT, Griffin CS, Yamasaki E, Drumm BT, Lane C, Sanders KM, Feng Earley Y, Earley S. TRPML1 channels initiate Ca 2+ sparks in vascular smooth muscle cells. Sci Signal 2020; 13:13/637/eaba1015. [PMID: 32576680 DOI: 10.1126/scisignal.aba1015] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
TRPML1 (transient receptor potential mucolipin 1) is a Ca2+-permeable, nonselective cation channel localized to the membranes of endosomes and lysosomes and is not present or functional on the plasma membrane. Ca2+ released from endosomes and lysosomes into the cytosol through TRPML1 channels is vital for trafficking, acidification, and other basic functions of these organelles. Here, we investigated the function of TRPML1 channels in fully differentiated contractile vascular smooth muscle cells (SMCs). In live-cell confocal imaging studies, we found that most endosomes and lysosomes in freshly isolated SMCs from cerebral arteries were essentially immobile. Using nanoscale super-resolution microscopy, we found that TRPML1 channels present in late endosomes and lysosomes formed stable complexes with type 2 ryanodine receptors (RyR2) on the sarcoplasmic reticulum (SR). Spontaneous Ca2+ signals resulting from the release of SR Ca2+ through RyR2s ("Ca2+ sparks") and corresponding Ca2+-activated K+ channel activity are critically important for balancing vasoconstriction. We found that these signals were essentially absent in SMCs from TRPML1-knockout (Mcoln1-/- ) mice. Using ex vivo pressure myography, we found that loss of this critical signaling cascade exaggerated the vasoconstrictor responses of cerebral and mesenteric resistance arteries. In vivo radiotelemetry studies showed that Mcoln1-/- mice were spontaneously hypertensive. We conclude that TRPML1 is crucial for the initiation of Ca2+ sparks in SMCs and the regulation of vascular contractility and blood pressure.
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Affiliation(s)
- Pratish Thakore
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV 89557-0318, USA
| | - Harry A T Pritchard
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV 89557-0318, USA
| | - Caoimhin S Griffin
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV 89557-0318, USA
| | - Evan Yamasaki
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV 89557-0318, USA
| | - Bernard T Drumm
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV 89557-0318, USA
| | - Conor Lane
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV 89557-0318, USA
| | - Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV 89557-0318, USA
| | - Yumei Feng Earley
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV 89557-0318, USA.,Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV 89557-0318, USA
| | - Scott Earley
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV 89557-0318, USA.
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11
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Song R, Hu XQ, Romero M, Holguin MA, Kagabo W, Xiao D, Wilson SM, Zhang L. Ryanodine receptor subtypes regulate Ca2+ sparks/spontaneous transient outward currents and myogenic tone of uterine arteries in pregnancy. Cardiovasc Res 2020; 117:792-804. [PMID: 32251501 DOI: 10.1093/cvr/cvaa089] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 02/18/2020] [Accepted: 03/31/2020] [Indexed: 12/12/2022] Open
Abstract
AIMS Our recent study demonstrated that increased Ca2+ sparks and spontaneous transient outward currents (STOCs) played an important role in uterine vascular tone and haemodynamic adaptation to pregnancy. The present study examined the role of ryanodine receptor (RyR) subtypes in regulating Ca2+ sparks/STOCs and myogenic tone in uterine arterial adaptation to pregnancy. METHODS AND RESULTS Uterine arteries isolated from non-pregnant and near-term pregnant sheep were used in the present study. Pregnancy increased the association of α and β1 subunits of large-conductance Ca2+-activated K+ (BKCa) channels and enhanced the co-localization of RyR1 and RyR2 with the β1 subunit in the uterine artery. In contrast, RyR3 was not co-localized with BKCa β1 subunit. Knockdown of RyR1 or RyR2 in uterine arteries of pregnant sheep downregulated the β1 but not α subunit of the BKCa channel and decreased the association of α and β1 subunits. Unlike RyR1 and RyR2, knockdown of RyR3 had no significant effect on either expression or association of BKCa subunits. In addition, knockdown of RyR1 or RyR2 significantly decreased Ca2+ spark frequency, suppressed STOCs frequency and amplitude, and increased pressure-dependent myogenic tone in uterine arteries of pregnant animals. RyR3 knockdown did not affect Ca2+ sparks/STOCs and myogenic tone in the uterine artery. CONCLUSION Together, the present study demonstrates a novel mechanistic paradigm of RyR subtypes in the regulation of Ca2+ sparks/STOCs and uterine vascular tone, providing new insights into the mechanisms underlying uterine vascular adaptation to pregnancy.
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Affiliation(s)
- Rui Song
- Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Xiang-Qun Hu
- Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Monica Romero
- Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Mark A Holguin
- Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Whitney Kagabo
- Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Daliao Xiao
- Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Sean M Wilson
- Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Lubo Zhang
- Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
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12
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Prenatal caffeine exposure induces down-regulation of the protein kinase A/ryanodine receptor/large-conductance Ca2+-activated K+ pathway in the cerebral arteries of old offspring rats. J Hypertens 2020; 38:679-691. [DOI: 10.1097/hjh.0000000000002303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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13
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Boerman EM, Segal SS. Aging alters spontaneous and neurotransmitter-mediated Ca 2+ signaling in smooth muscle cells of mouse mesenteric arteries. Microcirculation 2020; 27:e12607. [PMID: 31994289 DOI: 10.1111/micc.12607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 12/30/2019] [Accepted: 01/22/2020] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Aging impairs MA dilation by reducing the ability of sensory nerves to counteract sympathetic vasoconstriction. This study tested whether altered SMC Ca2+ signals to sympathetic (NE) and sensory (CGRP) neurotransmitters underlie aging-related deficits in vasodilation. METHODS MAs from young and old mice were pressurized and loaded with Fluo-4 dye for confocal measurement of SMC Ca2+ sparks and waves. Endothelial denudation resolved the influence of ECs. SMCs were immunolabeled for RyR isoforms and compared with transcript levels for RyRs and CGRP receptor components. RESULTS SMCs from young vs old mice exhibited more spontaneous Ca2+ spark sites with no difference in Ca2+ waves. NE reduced spark sites and increased waves for both groups; addition of CGRP restored sparks and reduced waves only for young mice. Endothelial denudation attenuated Ca2+ responses to CGRP for young but not old mice, which were already attenuated, suggesting a diminished role for ECs with aging. CGRP receptor expression was similar between ages with increased serum CGRP in old mice, where RyR1 expression was replaced by RyR3. CONCLUSION With aging, we suggest that altered RyR expression in SMCs contributes to impaired ability of sensory neurotransmission to restore Ca2+ signaling underlying vasomotor control during sympathetic activation.
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Affiliation(s)
- Erika M Boerman
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
| | - Steven S Segal
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA
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14
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Significant reduction of vascular reactivity with dantrolene and nimodipine in diabetic rats: a potential approach to cerebral vasospasm management in diabetes. Pharmacol Rep 2019; 72:126-134. [PMID: 32016838 DOI: 10.1007/s43440-019-00038-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 10/10/2019] [Accepted: 11/22/2019] [Indexed: 01/04/2023]
Abstract
BACKGROUND Diabetics have a higher risk of developing cerebral vasospasms (CVSPs) than non-diabetics. Current therapies are ineffective in reducing CVSPs, but a a combination of dantrolene and nimodipine may be a viable treatment. Considering the potentially harmful secondary effects of dantrolene, however, we evaluated the efficacy of 10 μM dantrolene compared to 50 μM dantrolene alone or in combination with 50 nM nimodipine. METHODS Dose-response curves for the phenylephrine (PHE)-induced contraction and acetylcholine (ACh)-induced relaxation were performed on aortic rings from diabetic and non-diabetic rats, before and after a 30-min incubation period with dantrolene (50 μM and 10 μM), alone or in combination with 50 nM nimodipine. RESULTS Whereas 50 μM dantrolene reduced PHE-induced contraction by 47% in diabetic rats and 29% in controls, 10 μM dantrolene failed to reduce this parameter in either group. Furthermore, 50 μM dantrolene reduced PHE-induced contraction by about 80% in both diabetic and controls when combined with nimodipine (N = 9, P < 0.05). The combination of 10 μM dantrolene and 50 nM nimodipine, however, was ineffective. Only 50 μM dantrolene improved endothelial dysfunction. CONCLUSIONS Improved endothelial-dependent relaxation and reduced vascular contractility with dantrolene are dose dependent. Thus, although dantrolene appears to be a promising alternative for the treatment of CVSPs when added to conventional therapies, careful titration should be performed to achieve a significant reduction in vascular hyperreactivity. Moreover, if our findings with rats are applicable to humans, the combined use of dantrolene and nimodipine at optimal doses may reduce CVSPs, especially in the diabetic population.
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15
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Ottolini M, Hong K, Sonkusare SK. Calcium signals that determine vascular resistance. WILEY INTERDISCIPLINARY REVIEWS. SYSTEMS BIOLOGY AND MEDICINE 2019; 11:e1448. [PMID: 30884210 PMCID: PMC6688910 DOI: 10.1002/wsbm.1448] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 02/07/2019] [Accepted: 02/14/2019] [Indexed: 12/19/2022]
Abstract
Small arteries in the body control vascular resistance, and therefore, blood pressure and blood flow. Endothelial and smooth muscle cells in the arterial walls respond to various stimuli by altering the vascular resistance on a moment to moment basis. Smooth muscle cells can directly influence arterial diameter by contracting or relaxing, whereas endothelial cells that line the inner walls of the arteries modulate the contractile state of surrounding smooth muscle cells. Cytosolic calcium is a key driver of endothelial and smooth muscle cell functions. Cytosolic calcium can be increased either by calcium release from intracellular stores through IP3 or ryanodine receptors, or the influx of extracellular calcium through ion channels at the cell membrane. Depending on the cell type, spatial localization, source of a calcium signal, and the calcium-sensitive target activated, a particular calcium signal can dilate or constrict the arteries. Calcium signals in the vasculature can be classified into several types based on their source, kinetics, and spatial and temporal properties. The calcium signaling mechanisms in smooth muscle and endothelial cells have been extensively studied in the native or freshly isolated cells, therefore, this review is limited to the discussions of studies in native or freshly isolated cells. This article is categorized under: Biological Mechanisms > Cell Signaling Laboratory Methods and Technologies > Imaging Models of Systems Properties and Processes > Mechanistic Models.
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Affiliation(s)
- Matteo Ottolini
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Pharmacology, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
| | - Kwangseok Hong
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Physical Education, Chung-Ang University, Seoul, 06974, South Korea
| | - Swapnil K. Sonkusare
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Pharmacology, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
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16
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Jo M, Trujillo AN, Yang Y, Breslin JW. Evidence of functional ryanodine receptors in rat mesenteric collecting lymphatic vessels. Am J Physiol Heart Circ Physiol 2019; 317:H561-H574. [PMID: 31274355 DOI: 10.1152/ajpheart.00564.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In the current study, the potential contributions of ryanodine receptors (RyRs) to intrinsic pumping and responsiveness to substance P (SP) were investigated in isolated rat mesenteric collecting lymphatic vessels. Responses to SP were characterized in lymphatic vessels in the absence or presence of pretreatment with nifedipine to block L-type Ca2+ channels, caffeine to block normal release and uptake of Ca2+ from the sarcoplasmic reticulum, ryanodine to block all RyR isoforms, or dantrolene to more selectively block RyR1 and RyR3. RyR expression and localization in lymphatics was also assessed by quantitative PCR and immunofluorescence confocal microscopy. The results show that SP normally elicits a significant increase in contraction frequency and a decrease in end-diastolic diameter. In the presence of nifedipine, phasic contractions stop, yet subsequent SP treatment still elicits a strong tonic contraction. Caffeine treatment gradually relaxes lymphatics, causing a loss of phasic contractions, and prevents subsequent SP-induced tonic contraction. Ryanodine also gradually diminishes phasic contractions but without causing vessel relaxation and significantly inhibits the SP-induced tonic contraction. Dantrolene treatment did not significantly impair lymphatic contractions nor the response to SP. The mRNA for all RyR isoforms is detectable in isolated lymphatics. RyR2 and RyR3 proteins are found predominantly in the collecting lymphatic smooth muscle layer. Collectively, the data suggest that SP-induced tonic contraction requires both extracellular Ca2+ plus Ca2+ release from internal stores and that RyRs play a role in the normal contractions and responsiveness to SP of rat mesenteric collecting lymphatics.NEW & NOTEWORTHY The mechanisms that govern contractions of lymphatic vessels remain unclear. Tonic contraction of lymphatic vessels caused by substance P was blocked by caffeine, which prevents normal uptake and release of Ca2+ from internal stores, but not nifedipine, which blocks L-type channel-mediated Ca2+ entry. Ryanodine, which also disrupts normal sarcoplasmic reticulum Ca2+ release and reuptake, significantly inhibited substance P-induced tonic contraction. Ryanodine receptors 2 and 3 were detected within the smooth muscle layer of collecting lymphatic vessels.
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Affiliation(s)
- Michiko Jo
- Department of Kampo Diagnostics, Institute of Natural Medicine, University of Toyama, Toyama, Japan.,Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Andrea N Trujillo
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Ying Yang
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Jerome W Breslin
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
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17
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Eckhardt J, Bachmann C, Sekulic-Jablanovic M, Enzmann V, Park KH, Ma J, Takeshima H, Zorzato F, Treves S. Extraocular muscle function is impaired in ryr3 -/- mice. J Gen Physiol 2019; 151:929-943. [PMID: 31085573 PMCID: PMC6605690 DOI: 10.1085/jgp.201912333] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 04/13/2019] [Indexed: 01/16/2023] Open
Abstract
Extraocular muscles are specialized skeletal muscles expressing a particular set
of proteins involved in calcium homeostasis, including RYR3. Eckhardt et al.
investigate extraocular muscle function in
ryr3−/− mice and show that
ablation of RYR3 significantly impacts vision. Calcium is an ubiquitous second messenger mediating numerous physiological
processes, including muscle contraction and neuronal excitability.
Ca2+ is stored in the ER/SR and is released into the cytoplasm
via the opening of intracellular inositol trisphosphate receptor and ryanodine
receptor calcium channels. Whereas in skeletal muscle, isoform 1 of the RYR is
the main channel mediating calcium release from the SR leading to muscle
contraction, the function of ubiquitously expressed ryanodine receptor 3 (RYR3)
is far from clear; it is not known whether RYR3 plays a role in
excitation–contraction coupling. We recently reported that human
extraocular muscles express high levels of RYR3, suggesting that such muscles
may be useful to study the function of this isoform of the Ca2+
channel. In the present investigation, we characterize the visual function of
ryr3−/− mice. We observe that
ablation of RYR3 affects both mechanical properties and calcium homeostasis in
extraocular muscles. These changes significantly impact vision. Our results
reveal for the first time an important role for RYR3 in extraocular muscle
function.
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Affiliation(s)
- Jan Eckhardt
- Department of Anesthesia, Basel University Hospital, Basel, Switzerland.,Department of Biomedicine, Basel University Hospital, Basel, Switzerland
| | - Christoph Bachmann
- Department of Anesthesia, Basel University Hospital, Basel, Switzerland.,Department of Biomedicine, Basel University Hospital, Basel, Switzerland
| | | | - Volker Enzmann
- Department of Ophthalmology, University Hospital of Bern, Bern, Switzerland.,Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Ki Ho Park
- Department of Surgery, Davis Heart & Lung Research Institute, The Ohio State University Medical Center, Columbus, OH
| | - Jianjie Ma
- Department of Surgery, Davis Heart & Lung Research Institute, The Ohio State University Medical Center, Columbus, OH
| | - Hiroshi Takeshima
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Francesco Zorzato
- Department of Anesthesia, Basel University Hospital, Basel, Switzerland.,Department of Biomedicine, Basel University Hospital, Basel, Switzerland.,Department of Life Sciences, Microbiology and Applied Pathology section, University of Ferrara, Ferrara, Italy
| | - Susan Treves
- Department of Anesthesia, Basel University Hospital, Basel, Switzerland .,Department of Biomedicine, Basel University Hospital, Basel, Switzerland.,Department of Life Sciences, Microbiology and Applied Pathology section, University of Ferrara, Ferrara, Italy
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18
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North KC, Chang J, Bukiya AN, Dopico AM. Extra-endothelial TRPV1 channels participate in alcohol and caffeine actions on cerebral artery diameter. Alcohol 2018; 73:45-55. [PMID: 30268908 DOI: 10.1016/j.alcohol.2018.04.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 04/09/2018] [Accepted: 04/09/2018] [Indexed: 12/14/2022]
Abstract
Alcohol (ethyl alcohol; ethanol) and caffeine are the two most widely used psychoactive substances in the world. Caffeine and ethanol have both been reported to constrict cerebral arteries in several species, including humans. We have recently shown that application of 10-μM caffeine mixed with 50 mM ethanol to in vitro pressurized cerebral arteries of rats reduced ethanol-induced constriction. This effect was dependent on the presence of nitric oxide (NO•) and could be observed in de-endothelialized arteries supplied with the NO donor sodium nitroprusside (SNP). The molecular target(s) of ethanol-caffeine interaction in cerebral arteries has remained unknown. In the present work, we used rat and mouse middle cerebral arteries (MCA) to identify the extra-endothelial effectors of NO-mediated, caffeine-induced protection against ethanol-evoked arterial constriction. Constriction of intact MCA of rat by either 50 mM ethanol or 10 μM caffeine was ablated in the presence of a selective TRPV1 pharmacological blocker. TRPV1 pharmacological block, but not block of TRPA1, PKG, or BK channels, removed caffeine-induced protection against ethanol-evoked rat MCA constriction, whether evaluated in arteries with intact endothelium or in SNP-supplemented, de-endothelialized arteries. In mouse arteries, caffeine-induced protection against ethanol-induced MCA constriction was significantly amplified, resulting in actual vasodilation, upon pharmacological block of TRPV1, and in TRPV1 knock-out arteries. Despite some species-specific differences, our study unequivocally demonstrates the presence of functional, extra-endothelial TRPV1 that participates in both endothelium-independent MCA constriction by separate exposure to ethanol or caffeine and caffeine-induced protection against ethanol-evoked MCA constriction.
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Affiliation(s)
- Kelsey C North
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38103, United States
| | - Jennifer Chang
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38103, United States
| | - Anna N Bukiya
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38103, United States
| | - Alex M Dopico
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38103, United States.
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19
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Bukiya AN, Blank PS, Rosenhouse-Dantsker A. Cholesterol intake and statin use regulate neuronal G protein-gated inwardly rectifying potassium channels. J Lipid Res 2018; 60:19-29. [PMID: 30420402 DOI: 10.1194/jlr.m081240] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/10/2018] [Indexed: 12/31/2022] Open
Abstract
Cholesterol, a critical component of the cellular plasma membrane, is essential for normal neuronal function. Cholesterol content is highest in the brain, where most cholesterol is synthesized de novo; HMG-CoA reductase controls the synthesis rate. Despite strict control, elevated blood cholesterol levels are common and are associated with various neurological disorders. G protein-gated inwardly rectifying potassium (GIRK) channels mediate the actions of inhibitory brain neurotransmitters. Loss of GIRK function enhances neuron excitability; gain of function reduces neuronal activity. However, the effect of dietary cholesterol or HMG-CoA reductase inhibition (i.e., statin therapy) on GIRK function remains unknown. Using a rat model, we compared the effects of a high-cholesterol versus normal diet both with and without atorvastatin, a widely prescribed HMG-CoA reductase inhibitor, on neuronal GIRK currents. The high-cholesterol diet increased hippocampal CA1 region cholesterol levels and correspondingly increased neuronal GIRK currents. Both phenomena were reversed by cholesterol depletion in vitro. Atorvastatin countered the high-cholesterol diet effects on neuronal cholesterol content and GIRK currents; these effects were reversed by cholesterol enrichment in vitro. Our findings suggest that high-cholesterol diet and atorvastatin therapy affect ion channel function in the brain by modulating neuronal cholesterol levels.
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Affiliation(s)
- Anna N Bukiya
- Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, TN 38163
| | - Paul S Blank
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
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20
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Hill BJF, Dalton RJ, Joseph BK, Thakali KM, Rusch NJ. 17β-estradiol reduces Ca v 1.2 channel abundance and attenuates Ca 2+ -dependent contractions in coronary arteries. Pharmacol Res Perspect 2018; 5. [PMID: 28971605 PMCID: PMC5625162 DOI: 10.1002/prp2.358] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 07/05/2017] [Accepted: 08/04/2017] [Indexed: 12/21/2022] Open
Abstract
One mechanism by which the female sex may protect against elevated coronary vascular tone is inhibition of Ca2+ entry into arterial smooth muscle cells (ASMCs). In vitro findings confirm that high estrogen concentrations directly inhibit voltage‐dependent Cav1.2 channels in coronary ASMCs. For this study, we hypothesized that the nonacute, in vitro exposure of coronary arteries to a low concentration of 17β‐estradiol (17βE) reduces the expression of Cav1.2 channel proteins in coronary ASMCs. Segments of the right coronary artery obtained from sexually mature female pigs were mounted for isometric tension recording. As expected, our results indicate that high concentrations (≥10 μmol/L) of 17βE acutely attenuated Ca2+‐dependent contractions to depolarizing KCl stimuli. Interestingly, culturing coronary arteries for 24 h in a 10,000‐fold lower concentration (1 nmol/L) of 17βE also attenuated KCl‐induced contractions and reduced the contractile response to the Cav1.2 agonist, FPL64176, by 50%. Western blots revealed that 1 nmol/L 17βE decreased protein expression of the pore‐forming α1C subunit (Cavα) of the Cav1.2 channel by 35%; this response did not depend on an intact endothelium. The 17βE‐induced loss of Cavα protein in coronary arteries was prevented by the estrogen ERα/ERβ antagonist, ICI 182,780, whereas the GPER antagonist, G15, did not prevent it. There was no effect of 1 nmol/L 17βE on Cavα transcript expression. We conclude that 17βE reduces Cav1.2 channel abundance in isolated coronary arteries by a posttranscriptional process. This unrecognized effect of estrogen may confer physiological protection against the development of abnormal Ca2+‐dependent coronary vascular tone.
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Affiliation(s)
- Brent J F Hill
- Department of Biology, University of Central Arkansas Conway, Conway, Arkansas
| | - Robin J Dalton
- Department of Biology, University of Central Arkansas Conway, Conway, Arkansas
| | - Biny K Joseph
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Keshari M Thakali
- Arkansas Children's Nutrition Center & Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Nancy J Rusch
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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21
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Gheibi S, Jeddi S, Kashfi K, Ghasemi A. Regulation of vascular tone homeostasis by NO and H 2S: Implications in hypertension. Biochem Pharmacol 2018; 149:42-59. [PMID: 29330066 PMCID: PMC5866223 DOI: 10.1016/j.bcp.2018.01.017] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 01/05/2018] [Indexed: 02/09/2023]
Abstract
Nitric oxide (NO) and hydrogen sulfide (H2S) are two gasotransmitters that are produced in the vasculature and contribute to the regulation of vascular tone. NO and H2S are synthesized in both vascular smooth muscle and endothelial cells; NO functions primarily through the sGC/cGMP pathway, and H2S mainly through activation of the ATP-dependent potassium channels; both leading to relaxation of vascular smooth muscle cells. A deficit in the NO/H2S homeostasis is involved in the pathogenesis of various cardiovascular diseases, especially hypertension. It is now becoming increasingly clear that there are important interactions between NO and H2S and that have a profound impact on vascular tone and this may provide insights into the new therapeutic interventions. The aim of this review is to provide a better understanding of individual and interactive roles of NO and H2S in vascular biology. Overall, available data indicate that both NO and H2S contribute to vascular (patho)physiology and in regulating blood pressure. In addition, boosting NO and H2S using various dietary sources or donors could be a hopeful therapeutic strategy in the management of hypertension.
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Affiliation(s)
- Sevda Gheibi
- Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Neurophysiology Research Center and Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sajad Jeddi
- Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Khosrow Kashfi
- Department of Molecular, Cellular and Biomedical Sciences, Sophie Davis School of Biomedical Education, City University of New York School of Medicine, NY, USA
| | - Asghar Ghasemi
- Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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22
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Crespo MJ, Roman M, Matias J, Morales M, Torres H, Quidgley J. Synergistic Effects of Dantrolene and Nimodipine on the Phenylephrine-Induced Contraction and ACh-Induced Relaxation in Aortic Rings from Diabetic Rats. Int J Endocrinol 2018; 2018:9790303. [PMID: 29849627 PMCID: PMC5933070 DOI: 10.1155/2018/9790303] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 02/27/2018] [Indexed: 12/24/2022] Open
Abstract
Diabetics have a higher risk of developing cerebral vasospasms (CVSP) than nondiabetics. The addition of the ryanodine receptor (RyR) blocker dantrolene to standard therapies reduces vasospasms in nondiabetics. Whether diabetics with CVSP also benefit from this drug, however, is unknown. We evaluated the effects of a 30 min incubation with dantrolene (50 μM), nimodipine (50 nM), and both drugs in combination, on phenylephrine- (PHE-) induced contraction and on acetylcholine- (ACh-) induced relaxation in aortic rings from streptozotocin (STZ) diabetic rats. Age-matched, nondiabetic rats served as controls. The oxidative stress markers malondialdehyde (MDA) and 4-hydroxyalkenal (4-HAE) were also evaluated in the presence and absence of dantrolene and nimodipine. The combination of these two drugs acted synergistically to reduce the PHE-induced contraction by 80% in both diabetics and controls. In contrast, it increased the Emax value for ACh-induced relaxation (from 56.46 ± 5.14% to 96.21 ± 7.50%; n = 6, P < 0.05), and it decreased MDA + 4-HAE values in diabetic rats only. These results suggest that the combination of dantrolene and nimodipine benefits both diabetics and nondiabetics by decreasing arterial tone synergistically.
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Affiliation(s)
- Maria J. Crespo
- Department of Physiology, University of Puerto Rico-School of Medicine, San Juan, PR, USA
- Department of Anesthesiology, University of Puerto Rico-School of Medicine, San Juan, PR, USA
| | - Marie Roman
- Department of Physiology, University of Puerto Rico-School of Medicine, San Juan, PR, USA
| | - Jonathan Matias
- Department of Anesthesiology, University of Puerto Rico-School of Medicine, San Juan, PR, USA
| | - Myrna Morales
- Department of Anesthesiology, University of Puerto Rico-School of Medicine, San Juan, PR, USA
| | - Hector Torres
- Department of Anesthesiology, University of Puerto Rico-School of Medicine, San Juan, PR, USA
| | - Jose Quidgley
- Department of Physiology, University of Puerto Rico-School of Medicine, San Juan, PR, USA
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Tykocki NR, Boerman EM, Jackson WF. Smooth Muscle Ion Channels and Regulation of Vascular Tone in Resistance Arteries and Arterioles. Compr Physiol 2017; 7:485-581. [PMID: 28333380 DOI: 10.1002/cphy.c160011] [Citation(s) in RCA: 212] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Vascular tone of resistance arteries and arterioles determines peripheral vascular resistance, contributing to the regulation of blood pressure and blood flow to, and within the body's tissues and organs. Ion channels in the plasma membrane and endoplasmic reticulum of vascular smooth muscle cells (SMCs) in these blood vessels importantly contribute to the regulation of intracellular Ca2+ concentration, the primary determinant of SMC contractile activity and vascular tone. Ion channels provide the main source of activator Ca2+ that determines vascular tone, and strongly contribute to setting and regulating membrane potential, which, in turn, regulates the open-state-probability of voltage gated Ca2+ channels (VGCCs), the primary source of Ca2+ in resistance artery and arteriolar SMCs. Ion channel function is also modulated by vasoconstrictors and vasodilators, contributing to all aspects of the regulation of vascular tone. This review will focus on the physiology of VGCCs, voltage-gated K+ (KV) channels, large-conductance Ca2+-activated K+ (BKCa) channels, strong-inward-rectifier K+ (KIR) channels, ATP-sensitive K+ (KATP) channels, ryanodine receptors (RyRs), inositol 1,4,5-trisphosphate receptors (IP3Rs), and a variety of transient receptor potential (TRP) channels that contribute to pressure-induced myogenic tone in resistance arteries and arterioles, the modulation of the function of these ion channels by vasoconstrictors and vasodilators, their role in the functional regulation of tissue blood flow and their dysfunction in diseases such as hypertension, obesity, and diabetes. © 2017 American Physiological Society. Compr Physiol 7:485-581, 2017.
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Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology, University of Vermont, Burlington, Vermont, USA
| | - Erika M Boerman
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, USA
| | - William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA
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Bukiya AN, Durdagi S, Noskov S, Rosenhouse-Dantsker A. Cholesterol up-regulates neuronal G protein-gated inwardly rectifying potassium (GIRK) channel activity in the hippocampus. J Biol Chem 2017; 292:6135-6147. [PMID: 28213520 DOI: 10.1074/jbc.m116.753350] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 02/13/2017] [Indexed: 02/06/2023] Open
Abstract
Hypercholesterolemia is a well known risk factor for the development of neurodegenerative disease. However, the underlying mechanisms are mostly unknown. In recent years, it has become increasingly evident that cholesterol-driven effects on physiology and pathophysiology derive from its ability to alter the function of a variety of membrane proteins including ion channels. Yet, the effect of cholesterol on G protein-gated inwardly rectifying potassium (GIRK) channels expressed in the brain is unknown. GIRK channels mediate the actions of inhibitory brain neurotransmitters. As a result, loss of GIRK function can enhance neuron excitability, whereas gain of GIRK function can reduce neuronal activity. Here we show that in rats on a high-cholesterol diet, cholesterol levels in hippocampal neurons are increased. We also demonstrate that cholesterol plays a critical role in modulating neuronal GIRK currents. Specifically, cholesterol enrichment of rat hippocampal neurons resulted in enhanced channel activity. In accordance, elevated currents upon cholesterol enrichment were also observed in Xenopus oocytes expressing GIRK2 channels, the primary GIRK subunit expressed in the brain. Furthermore, using planar lipid bilayers, we show that although cholesterol did not affect the unitary conductance of GIRK2, it significantly enhanced the frequency of channel openings. Last, combining computational and functional approaches, we identified two putative cholesterol-binding sites in the transmembrane domain of GIRK2. These findings establish that cholesterol plays a critical role in modulating GIRK activity in the brain. Because up-regulation of GIRK function can reduce neuronal activity, our findings may lead to novel approaches for prevention and therapy of cholesterol-driven neurodegenerative disease.
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Affiliation(s)
- Anna N Bukiya
- the Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, Tennessee 38103
| | - Serdar Durdagi
- the Centre for Molecular Simulation and Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4 Canada, and.,the Department of Biophysics, School of Medicine, Bahcesehir University, Istanbul 34353, Turkey
| | - Sergei Noskov
- the Centre for Molecular Simulation and Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4 Canada, and
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Daniels RE, Haq KT, Miller LS, Chia EW, Miura M, Sorrentino V, McGuire JJ, Stuyvers BD. Cardiac expression of ryanodine receptor subtype 3; a strategic component in the intracellular Ca 2+ release system of Purkinje fibers in large mammalian heart. J Mol Cell Cardiol 2017; 104:31-42. [PMID: 28111173 DOI: 10.1016/j.yjmcc.2017.01.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 12/08/2016] [Accepted: 01/18/2017] [Indexed: 10/20/2022]
Abstract
BACKGROUND Three distinct Ca2+ release channels were identified in dog P-cells: the ryanodine receptor subtype 2 (RyR2) was detected throughout the cell, while the ryanodine receptor subtype 3 (RyR3) and inositol phosphate sensitive Ca2+ release channel (InsP3R) were found in the cell periphery. How each of these channels contributes to the Ca2+ cycling of P-cells is unclear. Recent modeling of Ca2+ mobilization in P-cells suggested that Ca2+ sensitivity of Ca2+induced Ca2+release (CICR) was larger at the P-cell periphery. Our study examined whether this numerically predicted region of Ca2+ release exists in live P-cells. We compared the regional Ca2+ dynamics with the arrangement of intracellular Ca2+ release (CR) channels. METHODS Gene expression of CR channels was measured by qPCR in Purkinje fibers and myocardium of adult Yucatan pig hearts. We characterized the CR channels protein expression in isolated P-cells by immuno-fluorescence, laser scanning confocal microscopy, and 3D reconstruction. The spontaneous Ca2+ activity and electrically-evoked Ca2+ mobilization were imaged by 2D spinning disk confocal microscopy. Functional regions of P-cell were differentiated by the characteristics of local Ca2+ events. We used the Ca2+ propagation velocities as indicators of channel Ca2+ sensitivity. RESULTS RyR2 gene expression was identical in Purkinje fibers and myocardium (6 hearts) while RyR3 and InsP3R gene expressions were, respectively, 100 and 16 times larger in the Purkinje fibers. Specific fluorescent immuno-staining of Ca2+ release channels revealed an intermediate layer of RyR3 expression between a near-membrane InsP3R-region and a central RyR2-region. We found that cell periphery produced two distinct forms of spontaneous Ca2+-transients: (1) large asymmetrical Ca2+ sparks under the membrane, and (2) typical Ca2+-wavelets propagating exclusively around the core of the cell. Larger cell-wide Ca2+ waves (CWWs) appeared occasionally traveling in the longitudinal direction through the core of Pcells. Large sparks arose in a micrometric space overlapping the InsP3R expression. The InsP3R antagonists 2-aminoethoxydiphenyl borate (2-APB; 3μM) and xestospongin C (XeC; 50μM) dramatically reduced their frequency. The Ca2+ wavelets propagated in a 5-10μm thick layered space which matched the intermediate zone of RyR3 expression. The wavelet incidence was unchanged by 2-APB or XeC, but was reduced by 60% in presence of the RyR3 antagonist dantrolene (10μM). The velocity of wavelets was two times larger (86±16μm/s; n=14) compared to CWWs' (46±10μm/s; n=11; P<0.05). Electric stimulation triggered a uniform and large elevation of Ca2+ concentration under the membrane which preceded the propagation of Ca2+ into the interior of the cell. Elevated Cai propagated at 150μm/s (147±34μm/s; n=5) through the region equivalent to the zone of RyR3 expression. This velocity dropped by 50% (75±24μm/s; n=5) in the central region wherein predominant RyR2 expression was detected. CONCLUSION We identified two layers of distinct Ca2+ release channels in the periphery of Pcell: an outer layer of InsP3Rs under the membrane and an inner layer of RyR3s. The propagation of Ca2+ events in these layers revealed that Ca2+ sensitivity of Ca2+ release was larger in the RyR3 layer compared to that of other sub-cellular regions. We propose that RyR3 expression in P-cells plays a role in the stability of electric function of Purkinje fibers.
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Affiliation(s)
- Rebecca E Daniels
- Faculty of Medicine, Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Kazi T Haq
- Faculty of Medicine, Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Lawson S Miller
- Faculty of Medicine, Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Elizabeth W Chia
- Faculty of Medicine, Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Masahito Miura
- Department of Clinical Physiology, Health Science, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Vincenzo Sorrentino
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - John J McGuire
- Faculty of Medicine, Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Bruno D Stuyvers
- Faculty of Medicine, Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, NL, Canada.
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Ghosh D, Syed AU, Prada MP, Nystoriak MA, Santana LF, Nieves-Cintrón M, Navedo MF. Calcium Channels in Vascular Smooth Muscle. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2016; 78:49-87. [PMID: 28212803 DOI: 10.1016/bs.apha.2016.08.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Calcium (Ca2+) plays a central role in excitation, contraction, transcription, and proliferation of vascular smooth muscle cells (VSMs). Precise regulation of intracellular Ca2+ concentration ([Ca2+]i) is crucial for proper physiological VSM function. Studies over the last several decades have revealed that VSMs express a variety of Ca2+-permeable channels that orchestrate a dynamic, yet finely tuned regulation of [Ca2+]i. In this review, we discuss the major Ca2+-permeable channels expressed in VSM and their contribution to vascular physiology and pathology.
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Affiliation(s)
- D Ghosh
- University of California, Davis, CA, United States
| | - A U Syed
- University of California, Davis, CA, United States
| | - M P Prada
- University of California, Davis, CA, United States
| | - M A Nystoriak
- Diabetes and Obesity Center, University of Louisville, Louisville, KY, United States
| | - L F Santana
- University of California, Davis, CA, United States
| | | | - M F Navedo
- University of California, Davis, CA, United States.
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27
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Lopez RJ, Byrne S, Vukcevic M, Sekulic-Jablanovic M, Xu L, Brink M, Alamelu J, Voermans N, Snoeck M, Clement E, Muntoni F, Zhou H, Radunovic A, Mohammed S, Wraige E, Zorzato F, Treves S, Jungbluth H. An RYR1 mutation associated with malignant hyperthermia is also associated with bleeding abnormalities. Sci Signal 2016; 9:ra68. [PMID: 27382027 DOI: 10.1126/scisignal.aad9813] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Malignant hyperthermia is a potentially fatal hypermetabolic disorder triggered by halogenated anesthetics and the myorelaxant succinylcholine in genetically predisposed individuals. About 50% of susceptible individuals carry dominant, gain-of-function mutations in RYR1 [which encodes ryanodine receptor type 1 (RyR1)], though they have normal muscle function and no overt clinical symptoms. RyR1 is predominantly found in skeletal muscle but also at lower amounts in immune and smooth muscle cells, suggesting that RYR1 mutations may have a wider range of effects than previously suspected. Mild bleeding abnormalities have been described in patients with malignant hyperthermia carrying gain-of-function RYR1 mutations. We sought to determine the frequency and molecular basis for this symptom. We found that some patients with specific RYR1 mutations had abnormally high bleeding scores, whereas their healthy relatives did not. Knock-in mice with the malignant hyperthermia susceptibility RYR1 mutation Y522S (MHS RYR1Y522S) had longer bleeding times than their wild-type littermates. Primary vascular smooth muscle cells from RYR1Y522S knock-in mice exhibited a higher frequency of subplasmalemmal Ca(2+) sparks, leading to a more negative resting membrane potential. The bleeding defect of RYR1Y522S mice and of one patient was reversed by treatment with the RYR1 antagonist dantrolene, and Ca(2+) sparks in primary vascular smooth muscle cells from the MHS RYR1Y522S mice were blocked by ryanodine or dantrolene. Thus, RYR1 mutations may lead to prolonged bleeding by altering vascular smooth muscle cell function. The reversibility of the bleeding phenotype emphasizes the potential therapeutic value of dantrolene in the treatment of such bleeding disorders.
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Affiliation(s)
- Rubén J Lopez
- Departments of Biomedicine and Anesthesia, Basel University Hospital, Hebelstrasse 20, 4031 Basel, Switzerland
| | - Susan Byrne
- Department of Paediatric Neurology, Neuromuscular Service, Evelina Children's Hospital, St Thomas' Hospital, London SE1 7EH, UK
| | - Mirko Vukcevic
- Departments of Biomedicine and Anesthesia, Basel University Hospital, Hebelstrasse 20, 4031 Basel, Switzerland. Department of Biomedicine, Basel University Hospital, Hebelstrasse 20, 4031 Basel, Switzerland
| | - Marijana Sekulic-Jablanovic
- Departments of Biomedicine and Anesthesia, Basel University Hospital, Hebelstrasse 20, 4031 Basel, Switzerland
| | - Lifen Xu
- Department of Biomedicine, Basel University Hospital, Hebelstrasse 20, 4031 Basel, Switzerland
| | - Marijke Brink
- Department of Biomedicine, Basel University Hospital, Hebelstrasse 20, 4031 Basel, Switzerland
| | - Jay Alamelu
- Department of Haematology, Evelina Children's Hospital, St Thomas' Hospital, London SE1 7EH, UK
| | - Nicol Voermans
- Department of Neurology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Marc Snoeck
- National MH Investigation Unit, Department of Anesthesiology, Canisius Wilhelmina Hospital, 6532 Nijmegen, Netherlands
| | - Emma Clement
- Department of Clinical Genetics, Guy's Hospital, London SE1 7EH, UK
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Haiyan Zhou
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, London WC1N 1EH, UK
| | | | - Shehla Mohammed
- Department of Clinical Genetics, Guy's Hospital, London SE1 7EH, UK
| | - Elizabeth Wraige
- Department of Paediatric Neurology, Neuromuscular Service, Evelina Children's Hospital, St Thomas' Hospital, London SE1 7EH, UK
| | - Francesco Zorzato
- Departments of Biomedicine and Anesthesia, Basel University Hospital, Hebelstrasse 20, 4031 Basel, Switzerland. Department of Life Sciences, General Pathology Section, University of Ferrara, Via Borsari 46, 44100 Ferrara, Italy
| | - Susan Treves
- Departments of Biomedicine and Anesthesia, Basel University Hospital, Hebelstrasse 20, 4031 Basel, Switzerland. Department of Life Sciences, General Pathology Section, University of Ferrara, Via Borsari 46, 44100 Ferrara, Italy
| | - Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina Children's Hospital, St Thomas' Hospital, London SE1 7EH, UK. Randall Division of Cell and Molecular Biophysics, Muscle Signalling Section, King's College, London SE1 1UL, UK. Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London SE5 9RX, UK
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28
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Rosenberg J, Byrtus M, Stengl M. Original Research: Combined model of bladder detrusor smooth muscle and interstitial cells. Exp Biol Med (Maywood) 2016; 241:1853-64. [PMID: 27328937 DOI: 10.1177/1535370216655402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 05/26/2016] [Indexed: 11/15/2022] Open
Abstract
Although patients with lower urinary tract symptoms constitute a large and still growing population, understanding of bladder detrusor muscle physiology remains limited. Understanding the interactions between the detrusor smooth muscle cells and other bladder cell types (e.g. interstitial cells, IC) that may significantly contribute to coordinating and modulating detrusor contractions represents a considerable challenge. Computer modeling could help to elucidate some properties that are difficult to address experimentally; therefore, we developed in silico models of detrusor smooth muscle cell and interstitial cells, coupled through gap junctions. The models include all of the major ion conductances and transporters described in smooth muscle cell and interstitial cells in the literature. The model of normal detrusor muscle (smooth muscle cell and interstitial cells coupled through gap junctions) completely reproduced the experimental results obtained with detrusor strips in the presence of several pharmacological interventions (ryanodine, caffeine, nimodipine), whereas the model of smooth muscle cell alone (without interstitial cells) failed to reproduce the experimental results. Next, a model of overactive bladder, a highly prevalent clinical condition in both men and women with increasing incidence at older ages, was produced by modifying several processes as reported previously: a reduction of Ca(2+)-release through ryanodine receptors and a reduction of Ca(2+)-dependent K(+)-conductance with augmented gap junctional coupling. This model was also able to reproduce the pharmacological modulation of overactive bladder. In conclusion, a model of bladder detrusor muscle was developed that reproduced experimental results obtained in both normal and overactive bladder preparations. The results indicate that the non-smooth muscle cells of the detrusor (interstitial cells) contribute significantly to the contractile behavior of bladder detrusor muscle and should not be neglected. The model suggests that reduced Ca(2+)-release through ryanodine receptors and Ca(2+)-dependent K(+)-conductance together with augmented gap junctional coupling might play a major role in overactive bladder pathogenesis.
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Affiliation(s)
- Josef Rosenberg
- New Technologies Research Center, University of West Bohemia, Pilsen 30614, Czech Republic
| | - Miroslav Byrtus
- Department of Mechanics, University of West Bohemia, Pilsen 30614, Czech Republic
| | - Milan Stengl
- Department of Physiology, Faculty of Medicine in Pilsen, Charles University in Prague, Pilsen 32300, Czech Republic Biomedical Center, Faculty of Medicine in Pilsen, Charles University in Prague, Pilsen 32300, Czech Republic
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29
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Chen YF, Wang C, Zhang R, Wang H, Ma R, Jin S, Xiang JZ, Tang Q. Tacrolimus inhibits vasoconstriction by increasing Ca(2+) sparks in rat aorta. ACTA ACUST UNITED AC 2016; 36:8-13. [PMID: 26838733 DOI: 10.1007/s11596-016-1534-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 12/29/2015] [Indexed: 11/26/2022]
Abstract
The present study attempted to test a novel hypothesis that Ca(2+) sparks play an important role in arterial relaxation induced by tacrolimus. Recorded with confocal laser scanning microscopy, tacrolimus (10 µmol/L) increased the frequency of Ca(2+) sparks, which could be reversed by ryanodine (10 µmol/L). Electrophysiological experiments revealed that tacrolimus (10 µmol/L) increased the large-conductance Ca(2+)-activated K(+) currents (BKCa) in rat aortic vascular smooth muscle cells (AVSMCs), which could be blocked by ryanodine (10 µmol/L). Furthermore, tacrolimus (10 and 50 µmol/L) reduced the contractile force induced by norepinephrine (NE) or KCl in aortic vascular smooth muscle in a concentration-dependent manner, which could be also significantly attenuated by iberiotoxin (100 nmol/L) and ryanodine (10 µmol/L) respectively. In conclusion, tacrolimus could indirectly activate BKCa currents by increasing Ca(2+) sparks released from ryanodine receptors, which inhibited the NE- or KCl-induced contraction in rat aorta.
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MESH Headings
- Animals
- Aorta/cytology
- Aorta/metabolism
- Aorta/physiology
- Calcium Signaling
- Cells, Cultured
- Large-Conductance Calcium-Activated Potassium Channels/metabolism
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Norepinephrine/pharmacology
- Rats
- Rats, Sprague-Dawley
- Ryanodine/pharmacology
- Tacrolimus/pharmacology
- Vasoconstriction
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Affiliation(s)
- Yu-Fang Chen
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Chen Wang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Rui Zhang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Huan Wang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Rong Ma
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Si Jin
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Ji-Zhou Xiang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Qiang Tang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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30
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Dopico AM, Bukiya AN, Martin GE. Ethanol modulation of mammalian BK channels in excitable tissues: molecular targets and their possible contribution to alcohol-induced altered behavior. Front Physiol 2014; 5:466. [PMID: 25538625 PMCID: PMC4256990 DOI: 10.3389/fphys.2014.00466] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 11/13/2014] [Indexed: 11/30/2022] Open
Abstract
In most tissues, the function of Ca2+- and voltage-gated K+ (BK) channels is modified in response to ethanol concentrations reached in human blood during alcohol intoxication. In general, modification of BK current from ethanol-naïve preparations in response to brief ethanol exposure results from changes in channel open probability without modification of unitary conductance or change in BK protein levels in the membrane. Protracted and/or repeated ethanol exposure, however, may evoke changes in BK expression. The final ethanol effect on BK open probability leading to either BK current potentiation or BK current reduction is determined by an orchestration of molecular factors, including levels of activating ligand (Ca2+i), BK subunit composition and post-translational modifications, and the channel's lipid microenvironment. These factors seem to allosterically regulate a direct interaction between ethanol and a recognition pocket of discrete dimensions recently mapped to the channel-forming (slo1) subunit. Type of ethanol exposure also plays a role in the final BK response to the drug: in several central nervous system regions (e.g., striatum, primary sensory neurons, and supraoptic nucleus), acute exposure to ethanol reduces neuronal excitability by enhancing BK activity. In contrast, protracted or repetitive ethanol administration may alter BK subunit composition and membrane expression, rendering the BK complex insensitive to further ethanol exposure. In neurohypophyseal axon terminals, ethanol potentiation of BK channel activity leads to a reduction in neuropeptide release. In vascular smooth muscle, however, ethanol inhibition of BK current leads to cell contraction and vascular constriction.
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Affiliation(s)
- Alex M Dopico
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center Memphis, TN, USA
| | - Anna N Bukiya
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center Memphis, TN, USA
| | - Gilles E Martin
- Department of Psychiatry, The University of Massachusetts Medical School Worcester, MA, USA
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31
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Tano JY, Gollasch M. Calcium-activated potassium channels in ischemia reperfusion: a brief update. Front Physiol 2014; 5:381. [PMID: 25339909 PMCID: PMC4186282 DOI: 10.3389/fphys.2014.00381] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 09/13/2014] [Indexed: 12/24/2022] Open
Abstract
Ischemia and reperfusion (IR) injury constitutes one of the major causes of cardiovascular morbidity and mortality. The discovery of new therapies to block/mediate the effects of IR is therefore an important goal in the biomedical sciences. Dysfunction associated with IR involves modification of calcium-activated potassium channels (KCa) through different mechanisms, which are still under study. Respectively, the KCa family, major contributors to plasma membrane calcium influx in cells and essential players in the regulation of the vascular tone are interesting candidates. This family is divided into two groups including the large conductance (BKCa) and the small/intermediate conductance (SKCa/IKCa) K(+) channels. In the heart and brain, these channels have been described to offer protection against IR injury. BKCa and SKCa channels deserve special attention since new data demonstrate that these channels are also expressed in mitochondria. More studies are however needed to fully determine their potential use as therapeutic targets.
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Affiliation(s)
- Jean-Yves Tano
- Experimental and Clinical Research Center, Charité University Medicine - Max Delbrück Center (MDC) for Molecular Medicine Berlin, Germany ; Nephrology/Intensive Care Section, Charité University Medicine Berlin, Germany
| | - Maik Gollasch
- Experimental and Clinical Research Center, Charité University Medicine - Max Delbrück Center (MDC) for Molecular Medicine Berlin, Germany ; Nephrology/Intensive Care Section, Charité University Medicine Berlin, Germany
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32
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Fernández-Velasco M, Ruiz-Hurtado G, Gómez AM, Rueda A. Ca(2+) handling alterations and vascular dysfunction in diabetes. Cell Calcium 2014; 56:397-407. [PMID: 25218935 DOI: 10.1016/j.ceca.2014.08.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 07/30/2014] [Accepted: 08/07/2014] [Indexed: 12/12/2022]
Abstract
More than 65% of patients with diabetes mellitus die from cardiovascular disease or stroke. Hyperglycemia, due to either reduced insulin secretion or reduced insulin sensitivity, is the hallmark feature of diabetes mellitus. Vascular dysfunction is a distinctive phenotype found in both types of diabetes and could be responsible for the high incidence of stroke, heart attack, and organ damage in diabetic patients. In addition to well-documented endothelial dysfunction, Ca(2+) handling alterations in vascular smooth muscle cells (VSMCs) play a key role in the development and progression of vascular complications in diabetes. VSMCs provide not only structural integrity to the vessels but also control myogenic arterial tone and systemic blood pressure through global and local Ca(2+) signaling. The Ca(2+) signalosome of VSMCs is integrated by an extensive number of Ca(2+) handling proteins (i.e. channels, pumps, exchangers) and related signal transduction components, whose function is modulated by endothelial effectors. This review summarizes recent findings concerning alterations in endothelium and VSMC Ca(2+) signaling proteins that may contribute to the vascular dysfunction found in the diabetic condition.
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Affiliation(s)
| | - Gema Ruiz-Hurtado
- Unidad de Hipertensión, Instituto de Investigación imas12, Hospital 12 de Octubre, Madrid, Spain; Instituto Pluridisciplinar, Facultad de Farmacia, Universidad Complutense de Madrid, Spain
| | - Ana M Gómez
- Inserm, UMR S769, Faculté de Pharmacie, Université Paris Sud, Labex LERMIT, DHU TORINO, Châtenay-Malabry, France
| | - Angélica Rueda
- Departamento de Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, México City, Mexico.
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33
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Ye Y, Jian K, Jaggar JH, Bukiya AN, Dopico AM. Type 2 ryanodine receptors are highly sensitive to alcohol. FEBS Lett 2014; 588:1659-65. [PMID: 24631538 PMCID: PMC4193545 DOI: 10.1016/j.febslet.2014.03.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 02/27/2014] [Accepted: 03/01/2014] [Indexed: 11/16/2022]
Abstract
Exposure to ethanol levels reached in circulation during alcohol intoxication (>10mM) constricts cerebral arteries in rats and humans. Remarkably, targets and mechanisms underlying this action remain largely unidentified. Artery diameter is regulated by myocyte Ca(2+) sparks, a vasodilatory signal contributed to by type 2 ryanodine receptors (RyR2). Using laser confocal microscopy in rat cerebral arteries and bilayer electrophysiology we unveil that ethanol inhibits both Ca(2+) spark and RyR2 activity with IC50<20 mM, placing RyR2 among the ion channels that are most sensitive to ethanol. Alcohol directly targets RyR2 and its lipid microenvironment, leading to stabilization of RyR2 closed states.
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Affiliation(s)
- Yanping Ye
- Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Kuihuan Jian
- Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Jonathan H Jaggar
- Department of Physiology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Anna N Bukiya
- Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Alex M Dopico
- Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States.
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Tykocki NR, Wu B, Jackson WF, Watts SW. Divergent signaling mechanisms for venous versus arterial contraction as revealed by endothelin-1. J Vasc Surg 2014; 62:721-33. [PMID: 24726828 DOI: 10.1016/j.jvs.2014.03.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 03/07/2014] [Indexed: 01/15/2023]
Abstract
OBJECTIVE Venous function is underappreciated in its role in blood pressure determination, a physiologic parameter normally ascribed to changes in arterial function. Significant evidence points to the hormone endothelin-1 (ET-1) as being important to venous contributions to blood pressure. We hypothesized that the artery and vein should similarly depend on the signaling pathways stimulated by ET-1, specifically phospholipase C (PLC) activation. This produces two functional arms of signaling: diacylglycerol (DAG; protein kinase C [PKC] activation) and inositol trisphosphate (IP3) production (intracellular calcium release). METHODS The model was the male Sprague-Dawley rat. Isolated tissue baths were used to measure isometric contraction. Western blot and immunocytochemical analyses measured the magnitude of expression and site of expression, respectively, of IP3 receptors in smooth muscle/tissue. Pharmacologic methods were used to modify PLC activity and signaling elements downstream of PLC (IP3 receptors, PKC). RESULTS ET-1-induced contraction was PLC dependent in both tissues as the PLC inhibitor U-73122 significantly reduced contraction in aorta (86% ± 4% of control; P < .05) and vena cava (49% ± 11% of control; P < .05). However, ET-1-induced contraction was not significantly inhibited by the IP3 receptor inhibitor 2-aminoethoxydiphenylborane (100 μM) in vena cava (82% ± 8% of control; P = .23) but was in the aorta (55% ± 4% of control; P < .05). All three IP3 receptor isoforms were located in venous smooth muscle. IP3 receptors were functional in both tissues as the novel membrane-permeable IP3 analogue (Bt-IP3; 10 μM) contracted aorta and vena cava. Similarly, whereas the PKC inhibitor chelerythrine (10 μM) attenuated ET-1-induced contraction in vena cava and aorta (5% ± 2% and 50% ± 5% of control, respectively; P < .05), only the vena cava contracted to the DAG analogue 1-oleoyl-2-acetyl-sn-glycerol. CONCLUSIONS These findings suggest that ET-1 activates PLC in aorta and vena cava, but vena cava contraction to ET-1 may be largely IP3 independent. Rather, DAG—not IP3—may contribute to contraction to ET-1 in vena cava, in part by activation of PKC. These studies outline a fundamental difference between venous and arterial smooth muscle and further reinforce a heterogeneity of vascular smooth muscle function that could be taken advantage of for therapeutic development.
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Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Mich.
| | - BinXi Wu
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Mich
| | - William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Mich
| | - Stephanie W Watts
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Mich
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Gilbert G, Ducret T, Marthan R, Savineau JP, Quignard JF. Stretch-induced Ca2+ signalling in vascular smooth muscle cells depends on Ca2+ store segregation. Cardiovasc Res 2014; 103:313-23. [PMID: 24692174 DOI: 10.1093/cvr/cvu069] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AIM Calcium is a key second messenger that can be mobilized from both the extracellular medium and intracellular calcium stores. Pulmonary arterial smooth muscle cells (PASMCs) respond to stretch by a calcium increase, a mechanism enhanced during pulmonary hypertension (PH). We investigated the role of the spatial organization between plasma membrane stretch-activated channels (SACs) and intracellular calcium stores [sarcoplasmic reticulum (SR), mitochondria, and lysosomes) in response to stretch. METHODS AND RESULTS Studies were performed in freshly isolated PASMCs from both control and two different rat models of PH (chronically hypoxic and monocrotaline-treated rats). Co-immunolabellings revealed that the subcellular segregation between each subtype of SR ryanodine receptors (RyR1, RyR2, and RyR3), SERCA2 pumps (SERCA2a and SERCA2b), mitochondria, or lysosomes in freshly isolated PASMCs differs from control and PH PASMCs. In control PASMCs, stretching the membrane activates a Ca(2+) influx through SACs. This influx is amplified by cell hyperpolarization, a calcium release by subplasmalemmal RyR1 and is then buffered by mitochondria. In two different PH rat models, the calcium response to stretch is enhanced due to hyper-reactivity of SACs and a greater calcium amplification by all RyR subtypes. CONCLUSION The spatial organization of RyR and calcium stores in PASMCs is important for cell signalling and plays a causal role in PH.
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Affiliation(s)
- Guillaume Gilbert
- Centre de Recherche Cardio-Thoracique de Bordeaux, Universite de Bordeaux, Bordeaux F-33000, France Centre de Recherche Cardio-Thoracique de Bordeaux, INSERM, U 1045, Bordeaux F-33000, France
| | - Thomas Ducret
- Centre de Recherche Cardio-Thoracique de Bordeaux, Universite de Bordeaux, Bordeaux F-33000, France Centre de Recherche Cardio-Thoracique de Bordeaux, INSERM, U 1045, Bordeaux F-33000, France
| | - Roger Marthan
- Centre de Recherche Cardio-Thoracique de Bordeaux, Universite de Bordeaux, Bordeaux F-33000, France Centre de Recherche Cardio-Thoracique de Bordeaux, INSERM, U 1045, Bordeaux F-33000, France CHU Bordeaux, Exploration Fonctionnelle Respiratoire, Bordeaux F-33000, France
| | - Jean-Pierre Savineau
- Centre de Recherche Cardio-Thoracique de Bordeaux, Universite de Bordeaux, Bordeaux F-33000, France Centre de Recherche Cardio-Thoracique de Bordeaux, INSERM, U 1045, Bordeaux F-33000, France
| | - Jean-François Quignard
- Centre de Recherche Cardio-Thoracique de Bordeaux, Universite de Bordeaux, Bordeaux F-33000, France Centre de Recherche Cardio-Thoracique de Bordeaux, INSERM, U 1045, Bordeaux F-33000, France Centre de Recherche Cardio-Thoracique de Bordeaux, 146 rue Léo Saignat, Bat TP - 2ème étage, 33076 Bordeaux Cedex, France
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Guerrero-Hernández A, Ávila G, Rueda A. Ryanodine receptors as leak channels. Eur J Pharmacol 2013; 739:26-38. [PMID: 24291096 DOI: 10.1016/j.ejphar.2013.11.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 11/21/2013] [Indexed: 01/18/2023]
Abstract
Ryanodine receptors are Ca(2+) release channels of internal stores. This review focuses on those situations and conditions that transform RyRs from a finely regulated ion channel to an unregulated Ca(2+) leak channel and the pathological consequences of this alteration. In skeletal muscle, mutations in either CaV1.1 channel or RyR1 results in a leaky behavior of the latter. In heart cells, RyR2 functions normally as a Ca(2+) leak channel during diastole within certain limits, the enhancement of this activity leads to arrhythmogenic situations that are tackled with different pharmacological strategies. In smooth muscle, RyRs are involved more in reducing excitability than in stimulating contraction so the leak activity of RyRs in the form of Ca(2+) sparks, locally activates Ca(2+)-dependent potassium channels to reduce excitability. In neurons the enhanced activity of RyRs is associated with the development of different neurodegenerative disorders such as Alzheimer and Huntington diseases. It appears then that the activity of RyRs as leak channels can have both physiological and pathological consequences depending on the cell type and the metabolic condition.
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Affiliation(s)
| | | | - Angélica Rueda
- Departamento de Bioquímica, Cinvestav, Mexico city, México
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Up-regulation of ryanodine receptor expression increases the calcium-induced calcium release and spontaneous calcium signals in cerebral arteries from hindlimb unloaded rats. Pflugers Arch 2013; 466:1517-28. [DOI: 10.1007/s00424-013-1387-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 10/02/2013] [Accepted: 10/15/2013] [Indexed: 10/26/2022]
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Dabertrand F, Nelson MT, Brayden JE. Ryanodine receptors, calcium signaling, and regulation of vascular tone in the cerebral parenchymal microcirculation. Microcirculation 2013; 20:307-16. [PMID: 23216877 PMCID: PMC3612564 DOI: 10.1111/micc.12027] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2012] [Accepted: 11/21/2012] [Indexed: 11/27/2022]
Abstract
The cerebral blood supply is delivered by a surface network of pial arteries and arterioles from which arise (parenchymal) arterioles that penetrate into the cortex and terminate in a rich capillary bed. The critical regulation of CBF, locally and globally, requires precise vasomotor regulation of the intracerebral microvasculature. This vascular region is anatomically unique as illustrated by the presence of astrocytic processes that envelope almost the entire basolateral surface of PAs. There are, moreover, notable functional differences between pial arteries and PAs. For example, in pial VSMCs, local calcium release events ("calcium sparks") through ryanodine receptor (RyR) channels in SR membrane activate large conductance, calcium-sensitive potassium channels to modulate vascular diameter. In contrast, VSMCs in PAs express functional RyR and BK channels, but under physiological conditions, these channels do not oppose pressure-induced vasoconstriction. Here, we summarize the roles of ryanodine receptors in the parenchymal microvasculature under physiologic and pathologic conditions, and discuss their importance in the control of CBF.
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Affiliation(s)
- Fabrice Dabertrand
- Department of Pharmacology, College of Medicine, University of Vermont, Burlington, Vermont, USA.
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Quercetin as a fluorescent probe for the ryanodine receptor activity in Jurkat cells. Pflugers Arch 2013; 465:1101-19. [DOI: 10.1007/s00424-013-1235-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Revised: 01/29/2013] [Accepted: 01/31/2013] [Indexed: 02/07/2023]
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Tykocki NR, Thompson JM, Jackson WF, Watts SW. Ryanodine receptors are uncoupled from contraction in rat vena cava. Cell Calcium 2012. [PMID: 23177664 DOI: 10.1016/j.ceca.2012.10.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Ryanodine receptors (RyR) are Ca(2+)-sensitive ion channels in the sarcoplasmic reticulum (SR) membrane, and are important effectors of SR Ca(2+) release and smooth muscle excitation-contraction coupling. While the relationship between RyR activation and contraction is well characterized in arteries, little is known about the role of RyR in excitation-contraction coupling in veins. We hypothesized that RyR are present and directly coupled to contraction in rat aorta (RA) and vena cava (RVC). RA and RVC expressed mRNA for all 3 RyR subtypes, and immunofluorescence showed RyR protein was present in RA and RVC smooth muscle cells. RA and RVC rings contracted when Ca(2+) was re-introduced after stores depletion with thapsigargin (1μM), indicating both tissues contained intracellular Ca(2+) stores. To assess RyR function, contraction was then measured in RA and RVC exposed to the RyR activator caffeine (20mM). In RA, caffeine caused contraction that was attenuated by the RyR antagonists ryanodine (10μM) and tetracaine (100μM). However, caffeine (20mM) did not contract RVC. We next measured contraction and intracellular Ca(2+) (Ca(2+)(i)) simultaneously in RA and RVC exposed to caffeine. While caffeine increased Ca(2+)(i) and contracted RA, it had no significant effect on Ca(2+)(i) or contraction in RVC. These data suggest that ryanodine receptors, while present in both RA and RVC, are inactive and uncoupled from Ca(2+) release and contraction in RVC.
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Affiliation(s)
- N R Tykocki
- Department of Pharmacology and Toxicology, Michigan State University, 1355 Bogue St. Room B-445, East Lansing, MI 48824, USA.
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Dahan D, Ducret T, Quignard JF, Marthan R, Savineau JP, Estève E. Implication of the ryanodine receptor in TRPV4-induced calcium response in pulmonary arterial smooth muscle cells from normoxic and chronically hypoxic rats. Am J Physiol Lung Cell Mol Physiol 2012; 303:L824-33. [DOI: 10.1152/ajplung.00244.2011] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
There is a growing body of evidence indicating that transient receptor potential (TRP) channels are implicated in calcium signaling and various cellular functions in the pulmonary vasculature. The aim of this study was to investigate the expression, functional role, and coupling to reticulum calcium channels of the type 4 vanilloid TRP subfamily (TRPV4) in the pulmonary artery from both normoxic (Nx) and chronically hypoxic (CH) rats. Activation of TRPV4 with the specific agonist 4α-phorbol-12,13-didecanoate (4α-PDD, 5 μM) increased the intracellular calcium concentration ([Ca2+]i). This effect was significantly reduced by a high concentration of ryanodine (100 μM) or chronic caffeine (5 mM) that blocked ryanodine receptor (RyR) but was insensitive to xestospongin C (10 μM), an inositol trisphosphate receptor antagonist. Inhibition of RyR1 and RyR3 only with 10 μM of dantrolene did not attenuate the 4α-PDD-induced [Ca2+]i increase. Western blotting experiments revealed the expression of TRPV4 and RyR2 with an increase in both receptors in pulmonary arteries from CH rats vs. Nx rats. Accordingly, the 4α-PDD-activated current, measured with patch-clamp technique, was increased in pulmonary artery smooth muscle cells (PASMC) from CH rats vs. Nx rats. 4α-PDD increased isometric tension in artery rings, and this response was also potentiated under chronic hypoxia conditions. 4α-PDD-induced calcium response, current, and contraction were all inhibited by the selective TRPV4 blocker HC-067047. Collectively, our findings provide evidence of the interplay between TRPV4 and RyR2 in the Ca2+ release mechanism and contraction in PASMC. This study provides new insights onto the complex calcium signaling in PASMC and point out the importance of the TRPV4-RyR2 signaling pathway under hypoxic conditions that may lead to pulmonary hypertension.
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Affiliation(s)
- Diana Dahan
- Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France
- Institut National de la Santé et de la Recherche Médicale, U 1045, Bordeaux, France; and
| | - Thomas Ducret
- Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France
- Institut National de la Santé et de la Recherche Médicale, U 1045, Bordeaux, France; and
| | - Jean-François Quignard
- Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France
- Institut National de la Santé et de la Recherche Médicale, U 1045, Bordeaux, France; and
| | - Roger Marthan
- Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France
- Institut National de la Santé et de la Recherche Médicale, U 1045, Bordeaux, France; and
| | - Jean-Pierre Savineau
- Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France
- Institut National de la Santé et de la Recherche Médicale, U 1045, Bordeaux, France; and
| | - Eric Estève
- Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France
- Institut National de la Santé et de la Recherche Médicale, U 1045, Bordeaux, France; and
- Université Grenoble 1 UJF, Institut National de la Santé et de la Recherche Médicale U1042, La Tronche, France
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Hadley SR, Blood Q, Rubalcava M, Waskel E, Lumbard B, Le P, Longo LD, Buchholz JN, Wilson SM. Maternal high-altitude hypoxia and suppression of ryanodine receptor-mediated Ca2+ sparks in fetal sheep pulmonary arterial myocytes. Am J Physiol Lung Cell Mol Physiol 2012; 303:L799-813. [PMID: 22962012 DOI: 10.1152/ajplung.00009.2012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Ca(2+) sparks are fundamental Ca(2+) signaling events arising from ryanodine receptor (RyR) activation, events that relate to contractile and dilatory events in the pulmonary vasculature. Recent studies demonstrate that long-term hypoxia (LTH) can affect pulmonary arterial reactivity in fetal, newborn, and adult animals. Because RyRs are important to pulmonary vascular reactivity and reactivity changes with ontogeny and LTH we tested the hypothesis that RyR-generated Ca(2+) signals are more active before birth and that LTH suppresses these responses. We examined these hypotheses by performing confocal imaging of myocytes in living arteries and by performing wire myography studies. Pulmonary arteries (PA) were isolated from fetal, newborn, or adult sheep that lived at low altitude or from those that were acclimatized to 3,801 m for > 100 days. Confocal imaging demonstrated preservation of the distance between the sarcoplasmic reticulum, nucleus, and plasma membrane in PA myocytes. Maturation increased global Ca(2+) waves and Ca(2+) spark activity, with sparks becoming larger, wider, and slower. LTH preferentially depressed Ca(2+) spark activity in immature pulmonary arterial myocytes, and these sparks were smaller, wider, and slower. LTH also suppressed caffeine-elicited contraction in fetal PA but augmented contraction in the newborn and adult. The influence of both ontogeny and LTH on RyR-dependent cell excitability shed new light on the therapeutic potential of these channels for the treatment of pulmonary vascular disease in newborns as well as adults.
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Affiliation(s)
- Scott R Hadley
- Center for Perinatal Biology, Loma Linda University, California 92350, USA
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Westcott EB, Goodwin EL, Segal SS, Jackson WF. Function and expression of ryanodine receptors and inositol 1,4,5-trisphosphate receptors in smooth muscle cells of murine feed arteries and arterioles. J Physiol 2012; 590:1849-69. [PMID: 22331418 DOI: 10.1113/jphysiol.2011.222083] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
We tested the hypothesis that vasomotor control is differentially regulated between feed arteries and downstream arterioles from the cremaster muscle of C57BL/6 mice. In isolated pressurized arteries, confocal Ca(2+) imaging of smooth muscle cells (SMCs) revealed Ca(2+) sparks and Ca(2+) waves. Ryanodine receptor (RyR) antagonists (ryanodine and tetracaine) inhibited both sparks and waves but increased global Ca(2+) and myogenic tone. In arterioles, SMCs exhibited only Ca(2+) waves that were insensitive to ryanodine or tetracaine. Pharmacological interventions indicated that RyRs are functionally coupled to large-conductance, Ca(2+)-activated K(+) channels (BK(Ca)) in SMCs of arteries, whereas BK(Ca) appear functionally coupled to voltage-gated Ca2+ channels in SMCs of arterioles. Inositol 1,4,5-trisphosphate receptor (IP3R) antagonists (xestospongin D or 2-aminoethoxydiphenyl borate) or a phospholipase C inhibitor (U73122) attenuated Ca(2+) waves, global Ca(2+) and myogenic tone in arteries and arterioles but had no effect on arterial sparks. Real-time PCR of isolated SMCs revealed RyR2 as the most abundant isoform transcript; arteries expressed twice the RyR2 but only 65% the RyR3 of arterioles and neither vessel expressed RyR1. Immunofluorescent localisation of RyR protein indicated bright, clustered staining of arterial SMCs in contrast to diffuse staining in arteriolar SMCs. Expression of IP(3)R transcripts and protein immunofluorescence were similar in SMCs of both vessels with IP(3)R1>>IP(3)R2>IP(3)R3. Despite similar expression of IP(3)Rs and dependence of Ca(2+) waves on IP(3)Rs, these data illustrate pronounced regional heterogeneity in function and expression of RyRs between SMCs of the same vascular resistance network. We conclude that vasomotor control is differentially regulated in feed arteries vs. downstream arterioles.
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Affiliation(s)
- Erika B Westcott
- Department of Pharmacology & Toxicology, Michigan State University, East Lansing, MI 48824, USA
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Dabertrand F, Nelson MT, Brayden JE. Acidosis dilates brain parenchymal arterioles by conversion of calcium waves to sparks to activate BK channels. Circ Res 2011; 110:285-94. [PMID: 22095728 DOI: 10.1161/circresaha.111.258145] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Acidosis is a powerful vasodilator signal in the brain circulation. However, the mechanisms by which this response occurs are not well understood, particularly in the cerebral microcirculation. One important mechanism to dilate cerebral (pial) arteries is by activation of large-conductance, calcium-sensitive potassium (BK(Ca)) channels by local Ca(2+) signals (Ca(2+) sparks) through ryanodine receptors (RyRs). However, the role of this pathway in the brain microcirculation is not known. OBJECTIVE The objectives of this study were to determine the mechanism by which acidosis dilates brain parenchymal arterioles (PAs) and to elucidate the roles of RyRs and BK(Ca) channels in this response. METHODS AND RESULTS Internal diameter and vascular smooth muscle cell Ca(2+) signals were measured in isolated pressurized murine PAs, using imaging techniques. In physiological pH (7.4), vascular smooth muscle cells exhibited primarily RyR-dependent Ca(2+) waves. Reducing external pH from 7.4 to 7.0 in both normocapnic and hypercapnic conditions decreased Ca(2+) wave activity, and dramatically increased Ca(2+) spark activity. Acidic pH caused a dilation of PAs which was inhibited by about 60% by BK(Ca) channel or RyR blockers, in a nonadditive manner. Similarly, dilator responses to acidosis were reduced by nearly 60% in arterioles from BK(Ca) channel knockout mice. Dilations induced by acidic pH were unaltered by inhibitors of K(ATP) channels or nitric oxide synthase. CONCLUSIONS These results support the novel concept that acidification, by converting Ca(2+) waves to sparks, leads to the activation of BK(Ca) channels to induce dilation of cerebral PAs.
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Affiliation(s)
- Fabrice Dabertrand
- University of Vermont College of Medicine, Department of Pharmacology, 89 Beaumont Avenue, B-303 Given Building, Burlington, VT 05405-0068, USA
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Hill-Eubanks DC, Werner ME, Heppner TJ, Nelson MT. Calcium signaling in smooth muscle. Cold Spring Harb Perspect Biol 2011; 3:a004549. [PMID: 21709182 DOI: 10.1101/cshperspect.a004549] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Changes in intracellular Ca(2+) are central to the function of smooth muscle, which lines the walls of all hollow organs. These changes take a variety of forms, from sustained, cell-wide increases to temporally varying, localized changes. The nature of the Ca(2+) signal is a reflection of the source of Ca(2+) (extracellular or intracellular) and the molecular entity responsible for generating it. Depending on the specific channel involved and the detection technology employed, extracellular Ca(2+) entry may be detected optically as graded elevations in intracellular Ca(2+), junctional Ca(2+) transients, Ca(2+) flashes, or Ca(2+) sparklets, whereas release of Ca(2+) from intracellular stores may manifest as Ca(2+) sparks, Ca(2+) puffs, or Ca(2+) waves. These diverse Ca(2+) signals collectively regulate a variety of functions. Some functions, such as contractility, are unique to smooth muscle; others are common to other excitable cells (e.g., modulation of membrane potential) and nonexcitable cells (e.g., regulation of gene expression).
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Affiliation(s)
- David C Hill-Eubanks
- Department of Pharmacology, College of Medicine, University of Vermont, Burlington, Vermont 05405, USA
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