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Boskind M, Nelapudi N, Williamson G, Mendez B, Juarez R, Zhang L, Blood AB, Wilson CG, Puglisi JL, Wilson SM. Improved Workflow for Analysis of Vascular Myocyte Time-Series and Line-Scan Ca 2+ Imaging Datasets. Int J Mol Sci 2023; 24:9729. [PMID: 37298681 PMCID: PMC10253939 DOI: 10.3390/ijms24119729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/22/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023] Open
Abstract
Intracellular Ca2+ signals are key for the regulation of cellular processes ranging from myocyte contraction, hormonal secretion, neural transmission, cellular metabolism, transcriptional regulation, and cell proliferation. Measurement of cellular Ca2+ is routinely performed using fluorescence microscopy with biological indicators. Analysis of deterministic signals is reasonably straightforward as relevant data can be discriminated based on the timing of cellular responses. However, analysis of stochastic, slower oscillatory events, as well as rapid subcellular Ca2+ responses, takes considerable time and effort which often includes visual analysis by trained investigators, especially when studying signals arising from cells embedded in complex tissues. The purpose of the current study was to determine if full-frame time-series and line-scan image analysis workflow of Fluo-4 generated Ca2+ fluorescence data from vascular myocytes could be automated without introducing errors. This evaluation was addressed by re-analyzing a published "gold standard" full-frame time-series dataset through visual analysis of Ca2+ signals from recordings made in pulmonary arterial myocytes of en face arterial preparations. We applied a combination of data driven and statistical approaches with comparisons to our published data to assess the fidelity of the various approaches. Regions of interest with Ca2+ oscillations were detected automatically post hoc using the LCPro plug-in for ImageJ. Oscillatory signals were separated based on event durations between 4 and 40 s. These data were filtered based on cutoffs obtained from multiple methods and compared to the published manually curated "gold standard" dataset. Subcellular focal and rapid Ca2+ "spark" events from line-scan recordings were examined using SparkLab 5.8, which is a custom automated detection and analysis program. After filtering, the number of true positives, false positives, and false negatives were calculated through comparisons to visually derived "gold standard" datasets. Positive predictive value, sensitivity, and false discovery rates were calculated. There were very few significant differences between the automated and manually curated results with respect to quality of the oscillatory and Ca2+ spark events, and there were no systematic biases in the data curation or filtering techniques. The lack of statistical difference in event quality between manual data curation and statistically derived critical cutoff techniques leads us to believe that automated analysis techniques can be reliably used to analyze spatial and temporal aspects to Ca2+ imaging data, which will improve experiment workflow.
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Affiliation(s)
- Madison Boskind
- Lawrence D Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA 92373, USA; (M.B.); (N.N.); (G.W.); (B.M.); (L.Z.); (C.G.W.)
| | - Nikitha Nelapudi
- Lawrence D Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA 92373, USA; (M.B.); (N.N.); (G.W.); (B.M.); (L.Z.); (C.G.W.)
| | - Grace Williamson
- Lawrence D Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA 92373, USA; (M.B.); (N.N.); (G.W.); (B.M.); (L.Z.); (C.G.W.)
| | - Bobby Mendez
- Lawrence D Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA 92373, USA; (M.B.); (N.N.); (G.W.); (B.M.); (L.Z.); (C.G.W.)
| | - Rucha Juarez
- Advanced Imaging and Microscopy Core, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA;
| | - Lubo Zhang
- Lawrence D Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA 92373, USA; (M.B.); (N.N.); (G.W.); (B.M.); (L.Z.); (C.G.W.)
| | - Arlin B. Blood
- Lawrence D Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA 92373, USA; (M.B.); (N.N.); (G.W.); (B.M.); (L.Z.); (C.G.W.)
| | - Christopher G. Wilson
- Lawrence D Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA 92373, USA; (M.B.); (N.N.); (G.W.); (B.M.); (L.Z.); (C.G.W.)
| | - Jose Luis Puglisi
- Department of Biostatistics, School of Medicine, California Northstate University, Elk Grove, CA 95757, USA;
| | - Sean M. Wilson
- Lawrence D Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA 92373, USA; (M.B.); (N.N.); (G.W.); (B.M.); (L.Z.); (C.G.W.)
- Advanced Imaging and Microscopy Core, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA;
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Paudel R, Jafri MS, Ullah A. The Role of Ca 2+ Sparks in Force Frequency Relationships in Guinea Pig Ventricular Myocytes. Biomolecules 2022; 12:1577. [PMID: 36358926 PMCID: PMC9687237 DOI: 10.3390/biom12111577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 10/19/2022] [Accepted: 10/21/2022] [Indexed: 10/13/2023] Open
Abstract
Calcium sparks are the elementary Ca2+ release events in excitation-contraction coupling that underlie the Ca2+ transient. The frequency-dependent contractile force generated by cardiac myocytes depends upon the characteristics of the Ca2+ transients. A stochastic computational local control model of a guinea pig ventricular cardiomyocyte was developed, to gain insight into mechanisms of force-frequency relationship (FFR). This required the creation of a new three-state RyR2 model that reproduced the adaptive behavior of RyR2, in which the RyR2 channels transition into a different state when exposed to prolonged elevated subspace [Ca2+]. The model simulations agree with previous experimental and modeling studies on interval-force relations. Unlike previous common pool models, this local control model displayed stable action potential trains at 7 Hz. The duration and the amplitude of the [Ca2+]myo transients increase in pacing rates consistent with the experiments. The [Ca2+]myo transient reaches its peak value at 4 Hz and decreases afterward, consistent with experimental force-frequency curves. The model predicts, in agreement with previous modeling studies of Jafri and co-workers, diastolic sarcoplasmic reticulum, [Ca2+]sr, and RyR2 adaptation increase with the increased stimulation frequency, producing rising, rather than falling, amplitude of the myoplasmic [Ca2+] transients. However, the local control model also suggests that the reduction of the L-type Ca2+ current, with an increase in pacing frequency due to Ca2+-dependent inactivation, also plays a role in the negative slope of the FFR. In the simulations, the peak Ca2+ transient in the FFR correlated with the highest numbers of SR Ca2+ sparks: the larger average amplitudes of those sparks, and the longer duration of the Ca2+ sparks.
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Affiliation(s)
- Roshan Paudel
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA
- School of Computer, Mathematical, and Natural Sciences, Morgan State University, Baltimore, MD 21251, USA
| | - Mohsin Saleet Jafri
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Aman Ullah
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA
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Hu XQ, Song R, Dasgupta C, Romero M, Juarez R, Hanson J, Blood AB, Wilson SM, Zhang L. MicroRNA-210-mediated mitochondrial reactive oxygen species confer hypoxia-induced suppression of spontaneous transient outward currents in ovine uterine arteries. Br J Pharmacol 2022; 179:4640-4654. [PMID: 35776536 PMCID: PMC9474621 DOI: 10.1111/bph.15914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/26/2022] [Accepted: 06/22/2022] [Indexed: 12/05/2022] Open
Abstract
Background and Purpose Hypoxia during pregnancy is associated with increased uterine vascular resistance and elevated blood pressure both in women and female sheep. A previous study demonstrated a causal role of microRNA‐210 (miR‐210) in gestational hypoxia‐induced suppression of Ca2+ sparks/spontaneous transient outward currents (STOCs) in ovine uterine arteries, but the underlying mechanisms remain undetermined. We tested the hypothesis that miR‐210 perturbs mitochondrial metabolism and increases mitochondrial reactive oxygen species (mtROS) that confer hypoxia‐induced suppression of STOCs in uterine arteries. Experimental Approach Resistance‐sized uterine arteries were isolated from near‐term pregnant sheep and were treated ex vivo in normoxia and hypoxia (10.5% O2) for 48 h. Key Results Hypoxia increased mtROS and suppressed mitochondrial respiration in uterine arteries, which were also produced by miR‐210 mimic to normoxic arteries and blocked by antagomir miR‐210‐LNA in hypoxic arteries. Hypoxia or miR‐210 mimic inhibited Ca2+ sparks/STOCs and increased uterine arterial myogenic tone, which were inhibited by the mitochondria‐targeted antioxidant MitoQ. Hypoxia and miR‐210 down‐regulated iron–sulfur cluster scaffold protein (ISCU) in uterine arteries and knockdown of ISCU via siRNAs suppressed mitochondrial respiration, increased mtROS, and inhibited STOCs. In addition, blockade of mitochondrial electron transport chain with antimycin and rotenone inhibited large‐conductance Ca2+‐activated K+ channels, decreased STOCs and increased uterine arterial myogenic tone. Conclusion and Implications This study demonstrates a novel mechanistic role for the miR‐210‐ISCU‐mtROS axis in inhibiting Ca2+ sparks/STOCs in the maladaptation of uterine arteries and provides new insights into the understanding of mitochondrial perturbations in the pathogenesis of pregnancy complications resulted from hypoxia.
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Affiliation(s)
- Xiang-Qun Hu
- Lawrence D. Longo MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Rui Song
- Lawrence D. Longo MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Chiranjib Dasgupta
- Lawrence D. Longo MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Monica Romero
- Lawrence D. Longo MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Rucha Juarez
- Lawrence D. Longo MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Jenna Hanson
- Lawrence D. Longo MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Arlin B Blood
- Lawrence D. Longo MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Sean M Wilson
- Lawrence D. Longo MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Lubo Zhang
- Lawrence D. Longo MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
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Yang S, Li R, Chen J, Li Z, Huang Z, Xie W. Calcium Spark Detection and Event-Based Classification of Single Cardiomyocyte Using Deep Learning. Front Physiol 2021; 12:770051. [PMID: 34819876 PMCID: PMC8607692 DOI: 10.3389/fphys.2021.770051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 10/15/2021] [Indexed: 11/13/2022] Open
Abstract
Ca2+ sparks are the elementary Ca2+ release events in cardiomyocytes, altered properties of which lead to impaired Ca2+ handling and finally contribute to cardiac pathology under various diseases. Despite increasing use of machine-learning algorithms in deciphering the content of biological and medical data, Ca2+ spark images and data are yet to be deeply learnt and analyzed. In the present study, we developed a deep residual convolutional neural network method to detect Ca2+ sparks. Compared to traditional detection methods with arbitrarily defined thresholds to distinguish signals from noises, our new method detected more Ca2+ sparks with lower amplitudes but similar spatiotemporal distributions, thereby indicating that our new algorithm detected many very weak events that are usually omitted when using traditional detection methods. Furthermore, we proposed an event-based logistic regression and binary classification model to classify single cardiomyocytes using Ca2+ spark characteristics, which to date have generally been used only for simple statistical analyses and comparison between normal and diseased groups. Using this new detection algorithm and classification model, we succeeded in distinguishing wild type (WT) vs RyR2-R2474S± cardiomyocytes with 100% accuracy, and vehicle vs isoprenaline-insulted WT cardiomyocytes with 95.6% accuracy. The model can be extended to judge whether a small number of cardiomyocytes (and so the whole heart) are under a specific cardiac disease. Thus, this study provides a novel and powerful approach for the research and application of calcium signaling in cardiac diseases.
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Affiliation(s)
- Shengqi Yang
- Beijing Engineering Research Center for IoT Software and Systems, Beijing University of Technology, Beijing, China
| | - Ran Li
- Beijing Engineering Research Center for IoT Software and Systems, Beijing University of Technology, Beijing, China
| | - Jiliang Chen
- Beijing Engineering Research Center for IoT Software and Systems, Beijing University of Technology, Beijing, China
| | - Zhen Li
- Beijing Engineering Research Center for IoT Software and Systems, Beijing University of Technology, Beijing, China
| | - Zhangqin Huang
- Beijing Engineering Research Center for IoT Software and Systems, Beijing University of Technology, Beijing, China
| | - Wenjun Xie
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Institute of Health and Rehabilitation Science, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China
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Miguel-Dos-Santos R, Souza DS, Mesquita T. Fine-tuning SERCA activity to treat distinct heart failure syndromes. J Physiol 2021; 599:4253-4254. [PMID: 34387381 PMCID: PMC11033692 DOI: 10.1113/jp282044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 08/09/2021] [Indexed: 11/08/2022] Open
Affiliation(s)
| | - Diego Santos Souza
- Department of Biophysics, Federal University of São Paulo, São Paulo, Brazil
| | - Thássio Mesquita
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, USA
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Demydenko K, Sipido KR, Roderick HL. Ca2+ release via InsP3Rs enhances RyR recruitment during Ca2+ transients by increasing dyadic [Ca2+] in cardiomyocytes. J Cell Sci 2021; 134:269146. [PMID: 34125209 DOI: 10.1242/jcs.258671] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 06/08/2021] [Indexed: 11/20/2022] Open
Abstract
Excitation-contraction coupling (ECC) relies on temporally synchronized sarcoplasmic reticulum (SR) Ca2+ release via ryanodine receptors (RyRs) at dyadic membrane compartments. Neurohormones, such as endothelin-1 (ET-1), that act via Gαq-associated G protein-coupled receptors (GPCRs) modulate Ca2+ dynamics during ECC and induce SR Ca2+ release events involving Ca2+ release via inositol 1,4,5-trisphosphate (InsP3) receptors (InsP3Rs). How the relatively modest Ca2+ release via InsP3Rs elicits this action is not resolved. Here, we investigated whether the actions of InsP3Rs on Ca2+ handling during ECC were mediated by a direct influence on dyadic Ca2+ levels and whether this mechanism contributes to the effects of ET-1. Using a dyad-targeted genetically encoded Ca2+ reporter, we found that InsP3R activation augmented dyadic Ca2+ fluxes during Ca2+ transients and increased Ca2+ sparks. RyRs were required for these effects. These data provide the first direct demonstration of GPCR and InsP3 effects on dyadic Ca2+, and support the notion that Ca2+ release via InsP3Rs influences Ca2+ transients during ECC by facilitating the activation and recruitment of proximal RyRs. We propose that this mechanism contributes to neurohormonal modulation of cardiac function. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Kateryna Demydenko
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000, Leuven, Belgium
| | - Karin R Sipido
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000, Leuven, Belgium
| | - H Llewelyn Roderick
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000, Leuven, Belgium
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Fong SPT, Agrawal S, Gong M, Zhao J. Modulated Calcium Homeostasis and Release Events Under Atrial Fibrillation and Its Risk Factors: A Meta-Analysis. Front Cardiovasc Med 2021; 8:662914. [PMID: 34355025 PMCID: PMC8329373 DOI: 10.3389/fcvm.2021.662914] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 06/11/2021] [Indexed: 12/26/2022] Open
Abstract
Background: Atrial fibrillation (AF) is associated with calcium (Ca2+) handling remodeling and increased spontaneous calcium release events (SCaEs). Nevertheless, its exact mechanism remains unclear, resulting in suboptimal primary and secondary preventative strategies. Methods: We searched the PubMed database for studies that investigated the relationship between SCaEs and AF and/or its risk factors. Meta-analysis was used to examine the Ca2+ mechanisms involved in the primary and secondary AF preventative groups. Results: We included a total of 74 studies, out of the identified 446 publications from inception (1982) until March 31, 2020. Forty-five were primary and 29 were secondary prevention studies for AF. The main Ca2+ release events, calcium transient (standardized mean difference (SMD) = 0.49; I2 = 35%; confidence interval (CI) = 0.33–0.66; p < 0.0001), and spark amplitude (SMD = 0.48; I2 = 0%; CI = −0.98–1.93; p = 0.054) were enhanced in the primary diseased group, while calcium transient frequency was increased in the secondary group. Calcium spark frequency was elevated in both the primary diseased and secondary AF groups. One of the key cardiac currents, the L-type calcium current (ICaL) was significantly downregulated in primary diseased (SMD = −1.07; I2 = 88%; CI = −1.94 to −0.20; p < 0.0001) and secondary AF groups (SMD = −1.28; I2 = 91%; CI = −2.04 to −0.52; p < 0.0001). Furthermore, the sodium–calcium exchanger (INCX) and NCX1 protein expression were significantly enhanced in the primary diseased group, while only NCX1 protein expression was shown to increase in the secondary AF studies. The phosphorylation of the ryanodine receptor at S2808 (pRyR-S2808) was significantly elevated in both the primary and secondary groups. It was increased in the primary diseased and proarrhythmic subgroups (SMD = 0.95; I2 = 64%; CI = 0.12–1.79; p = 0.074) and secondary AF group (SMD = 0.66; I2 = 63%; CI = 0.01–1.31; p < 0.0001). Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) expression was elevated in the primary diseased and proarrhythmic drug subgroups but substantially reduced in the secondary paroxysmal AF subgroup. Conclusions: Our study identified that ICaL is reduced in both the primary and secondary diseased groups. Furthermore, pRyR-S2808 and NCX1 protein expression are enhanced. The remodeling leads to elevated Ca2+ functional activities, such as increased frequencies or amplitude of Ca2+ spark and Ca2+ transient. The main difference identified between the primary and secondary diseased groups is SERCA expression, which is elevated in the primary diseased group and substantially reduced in the secondary paroxysmal AF subgroup. We believe our study will add new evidence to AF mechanisms and treatment targets.
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Affiliation(s)
- Sarah Pei Ting Fong
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Shaleka Agrawal
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Mengqi Gong
- Department of Cardiology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
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Abstract
Vascular smooth muscle cells (VSMCs) of small peripheral arteries contribute to blood pressure control by adapting their contractile state. These adaptations depend on the VSMC cytosolic Ca2+ concentration, regulated by complex local elementary Ca2+ signaling pathways. Ca2+ sparks represent local, transient, rapid calcium release events from a cluster of ryanodine receptors (RyRs) in the sarcoplasmic reticulum. In arterial SMCs, Ca2+ sparks activate nearby calcium-dependent potassium channels, cause membrane hyperpolarization and thus decrease the global intracellular [Ca2+] to oppose vasoconstriction. Arterial SMC Cav1.2 L-type channels regulate intracellular calcium stores content, which in turn modulates calcium efflux through RyRs. Cav3.2 T-type channels contribute to a minor extend to Ca2+ spark generation in certain types of arteries. Their localization within cell membrane caveolae is essential. We summarize present data on local elementary calcium signaling (Ca2+ sparks) in arterial SMCs with focus on RyR isoforms, large-conductance calcium-dependent potassium (BKCa) channels, and cell membrane-bound calcium channels (Cav1.2 and Cav3.2), particularly in caveolar microdomains.
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Affiliation(s)
- Gang Fan
- Charité - Universitätsmedizin Berlin, Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Yingqiu Cui
- Charité - Universitätsmedizin Berlin, Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Maik Gollasch
- Charité - Universitätsmedizin Berlin, Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Berlin, Germany
| | - Mario Kassmann
- Charité - Universitätsmedizin Berlin, Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Berlin, Germany
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Fowler ED, Wang N, Hezzell M, Chanoit G, Hancox JC, Cannell MB. Arrhythmogenic late Ca 2+ sparks in failing heart cells and their control by action potential configuration. Proc Natl Acad Sci U S A 2020; 117:2687-92. [PMID: 31969455 DOI: 10.1073/pnas.1918649117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Sudden death in heart failure patients is a major clinical problem worldwide, but it is unclear how arrhythmogenic early afterdepolarizations (EADs) are triggered in failing heart cells. To examine EAD initiation, high-sensitivity intracellular Ca2+ measurements were combined with action potential voltage clamp techniques in a physiologically relevant heart failure model. In failing cells, the loss of Ca2+ release synchrony at the start of the action potential leads to an increase in number of microscopic intracellular Ca2+ release events ("late" Ca2+ sparks) during phase 2-3 of the action potential. These late Ca2+ sparks prolong the Ca2+ transient that activates contraction and can trigger propagating microscopic Ca2+ ripples, larger macroscopic Ca2+ waves, and EADs. Modification of the action potential to include steps to different potentials revealed the amount of current generated by these late Ca2+ sparks and their (subsequent) spatiotemporal summation into Ca2+ ripples/waves. Comparison of this current to the net current that causes action potential repolarization shows that late Ca2+ sparks provide a mechanism for EAD initiation. Computer simulations confirmed that this forms the basis of a strong oscillatory positive feedback system that can act in parallel with other purely voltage-dependent ionic mechanisms for EAD initiation. In failing heart cells, restoration of the action potential to a nonfailing phase 1 configuration improved the synchrony of excitation-contraction coupling, increased Ca2+ transient amplitude, and suppressed late Ca2+ sparks. Therapeutic control of late Ca2+ spark activity may provide an additional approach for treating heart failure and reduce the risk for sudden cardiac death.
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Moccia F, Lodola F, Stadiotti I, Pilato CA, Bellin M, Carugo S, Pompilio G, Sommariva E, Maione AS. Calcium as a Key Player in Arrhythmogenic Cardiomyopathy: Adhesion Disorder or Intracellular Alteration? Int J Mol Sci 2019; 20:E3986. [PMID: 31426283 DOI: 10.3390/ijms20163986] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 08/08/2019] [Accepted: 08/14/2019] [Indexed: 12/20/2022] Open
Abstract
Arrhythmogenic cardiomyopathy (ACM) is an inherited heart disease characterized by sudden death in young people and featured by fibro-adipose myocardium replacement, malignant arrhythmias, and heart failure. To date, no etiological therapies are available. Mutations in desmosomal genes cause abnormal mechanical coupling, trigger pro-apoptotic signaling pathways, and induce fibro-adipose replacement. Here, we discuss the hypothesis that the ACM causative mechanism involves a defect in the expression and/or activity of the cardiac Ca2+ handling machinery, focusing on the available data supporting this hypothesis. The Ca2+ toolkit is heavily remodeled in cardiomyocytes derived from a mouse model of ACM defective of the desmosomal protein plakophilin-2. Furthermore, ACM-related mutations were found in genes encoding for proteins involved in excitation‒contraction coupling, e.g., type 2 ryanodine receptor and phospholamban. As a consequence, the sarcoplasmic reticulum becomes more eager to release Ca2+, thereby inducing delayed afterdepolarizations and impairing cardiac contractility. These data are supported by preliminary observations from patient induced pluripotent stem-cell-derived cardiomyocytes. Assessing the involvement of Ca2+ signaling in the pathogenesis of ACM could be beneficial in the treatment of this life-threatening disease.
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12
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Kaßmann M, Szijártó IA, García‐Prieto CF, Fan G, Schleifenbaum J, Anistan Y, Tabeling C, Shi Y, le Noble F, Witzenrath M, Huang Y, Markó L, Nelson MT, Gollasch M. Role of Ryanodine Type 2 Receptors in Elementary Ca 2+ Signaling in Arteries and Vascular Adaptive Responses. J Am Heart Assoc 2019; 8:e010090. [PMID: 31030596 PMCID: PMC6512102 DOI: 10.1161/jaha.118.010090] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 02/07/2019] [Indexed: 12/29/2022]
Abstract
Background Hypertension is the major risk factor for cardiovascular disease, the most common cause of death worldwide. Resistance arteries are capable of adapting their diameter independently in response to pressure and flow-associated shear stress. Ryanodine receptors (RyRs) are major Ca2+-release channels in the sarcoplasmic reticulum membrane of myocytes that contribute to the regulation of contractility. Vascular smooth muscle cells exhibit 3 different RyR isoforms (RyR1, RyR2, and RyR3), but the impact of individual RyR isoforms on adaptive vascular responses is largely unknown. Herein, we generated tamoxifen-inducible smooth muscle cell-specific RyR2-deficient mice and tested the hypothesis that vascular smooth muscle cell RyR2s play a specific role in elementary Ca2+ signaling and adaptive vascular responses to vascular pressure and/or flow. Methods and Results Targeted deletion of the Ryr2 gene resulted in a complete loss of sarcoplasmic reticulum-mediated Ca2+-release events and associated Ca2+-activated, large-conductance K+ channel currents in peripheral arteries, leading to increased myogenic tone and systemic blood pressure. In the absence of RyR2, the pulmonary artery pressure response to sustained hypoxia was enhanced, but flow-dependent effects, including blood flow recovery in ischemic hind limbs, were unaffected. Conclusions Our results establish that RyR2-mediated Ca2+-release events in VSCM s specifically regulate myogenic tone (systemic circulation) and arterial adaptation in response to changes in pressure (hypoxic lung model), but not flow. They further suggest that vascular smooth muscle cell-expressed RyR2 deserves scrutiny as a therapeutic target for the treatment of vascular responses in hypertension and chronic vascular diseases.
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Affiliation(s)
- Mario Kaßmann
- Experimental and Clinical Research Centera joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular MedicineCharité–Universitätsmedizin BerlinBerlinGermany
- DZHK (German Centre for Cardiovascular Research), partner site BerlinBerlinGermany
| | - István András Szijártó
- Experimental and Clinical Research Centera joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular MedicineCharité–Universitätsmedizin BerlinBerlinGermany
| | - Concha F. García‐Prieto
- Experimental and Clinical Research Centera joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular MedicineCharité–Universitätsmedizin BerlinBerlinGermany
- Department of Pharmaceutical and Health SciencesFacultad de FarmaciaUniversidad CEU San PabloMadridSpain
| | - Gang Fan
- Experimental and Clinical Research Centera joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular MedicineCharité–Universitätsmedizin BerlinBerlinGermany
| | - Johanna Schleifenbaum
- Experimental and Clinical Research Centera joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular MedicineCharité–Universitätsmedizin BerlinBerlinGermany
| | - Yoland‐Marie Anistan
- Experimental and Clinical Research Centera joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular MedicineCharité–Universitätsmedizin BerlinBerlinGermany
| | - Christoph Tabeling
- Department of Infectious Diseases and Pulmonary MedicineCharité–Universitätsmedizin BerlinBerlinGermany
| | - Yu Shi
- Medical Clinic for Hematology, Oncology and Tumor ImmunologyCharité–Universitätsmedizin BerlinBerlinGermany
| | - Ferdinand le Noble
- Department of Cell and Developmental BiologyITG (Institute of Toxicology and Genetics)Karlsruhe Institute of TechnologyKarlsruheGermany
| | - Martin Witzenrath
- Department of Infectious Diseases and Pulmonary MedicineCharité–Universitätsmedizin BerlinBerlinGermany
| | - Yu Huang
- Institute of Vascular Medicine and School of Biomedical SciencesChinese University of Hong KongChina
| | - Lajos Markó
- Medical Clinic for Hematology, Oncology and Tumor ImmunologyCharité–Universitätsmedizin BerlinBerlinGermany
| | - Mark T. Nelson
- Department of PharmacologyCollege of MedicineThe University of VermontBurlingtonVT
| | - Maik Gollasch
- Experimental and Clinical Research Centera joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular MedicineCharité–Universitätsmedizin BerlinBerlinGermany
- DZHK (German Centre for Cardiovascular Research), partner site BerlinBerlinGermany
- Medical Clinic for Nephrology and Internal Intensive CareCharité–Universitätsmedizin BerlinBerlinGermany
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13
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Shen CP, Romero M, Brunelle A, Wolfe C, Dobyns A, Francis M, Taylor MS, Puglisi JL, Longo LD, Zhang L, Wilson CG, Wilson SM. Long-term high-altitude hypoxia influences pulmonary arterial L-type calcium channel-mediated Ca 2+ signals and contraction in fetal and adult sheep. Am J Physiol Regul Integr Comp Physiol 2017; 314:R433-R446. [PMID: 29167165 DOI: 10.1152/ajpregu.00154.2017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Long-term hypoxia (LTH) has a profound effect on pulmonary arterial vasoconstriction in the fetus and adult. Dysregulation in Ca2+ signaling is important during the development of LTH-induced pulmonary hypertension. In the present study, we tested the hypothesis that L-type Ca2+ channels (CaL), which are voltage dependent and found in smooth, skeletal, and cardiac muscle, are important in the adaptation of pulmonary arterial contractions in postnatal maturation and in response to LTH. Pulmonary arteries were isolated from fetal or adult sheep maintained at low or high altitude (3,801 m) for >100 days. The effects were measured using an L-type Ca2+ channel opener FPL 64176 (FPL) in the presence or absence of an inhibitor, Nifedipine (NIF) on arterial contractions, intracellular Ca2+ oscillations, and ryanodine receptor-driven Ca2+ sparks. FPL induced pulmonary arterial contractions in all groups were sensitive to NIF. However, when compared with 125 mM K+, FPL contractions were greater in fetuses than in adults. FPL reduced Ca2+ oscillations in myocytes of adult but not fetal arteries, independently of altitude. The FPL effects on Ca2+ oscillations were reversed by NIF in myocytes of hypoxic but not normoxic adults. FPL failed to enhance Ca2+ spark frequency and had little impact on spatiotemporal firing characteristics. These data suggest that CaL-dependent contractions are largely uncoupled from intracellular Ca2+ oscillations and the development of Ca2+ sparks. This raises questions regarding the coupling of pulmonary arterial contractility to membrane depolarization, attendant CaL facilitation, and the related associations with the activation of Ca2+ oscillations and Ca2+ sparks.
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Affiliation(s)
- Christine P Shen
- Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda University School of Medicine , Loma Linda, California
| | - Monica Romero
- Advanced Imaging and Microscopy Core, Loma Linda University School of Medicine , Loma Linda, California
| | - Alexander Brunelle
- Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda University School of Medicine , Loma Linda, California
| | - Craig Wolfe
- Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda University School of Medicine , Loma Linda, California
| | - Abigail Dobyns
- Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda University School of Medicine , Loma Linda, California
| | - Michael Francis
- Department of Physiology, University of South Alabama College of Medicine , Mobile, Alabama
| | - Mark S Taylor
- Department of Physiology, University of South Alabama College of Medicine , Mobile, Alabama
| | - Jose L Puglisi
- Department of Biostatistics, California Northstate University School of Medicine , Elk Grove, California
| | - Lawrence D Longo
- Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda University School of Medicine , Loma Linda, California
| | - Lubo Zhang
- Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda University School of Medicine , Loma Linda, California
| | - Christopher G Wilson
- Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda University School of Medicine , Loma Linda, California
| | - Sean M Wilson
- Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda University School of Medicine , Loma Linda, California
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14
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Wullschleger M, Blanch J, Egger M. Functional local crosstalk of inositol 1,4,5-trisphosphate receptor- and ryanodine receptor-dependent Ca2+ release in atrial cardiomyocytes. Cardiovasc Res 2017; 113:542-552. [PMID: 28158491 DOI: 10.1093/cvr/cvx020] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 01/31/2017] [Indexed: 11/12/2022] Open
Abstract
Aims Enhanced inositol 1,4,5-trisphosphate receptor (InsP3R2) expression has been associated with a variety of proarrhythmogenic cardiac disorders. The functional interaction between the two major Ca2+ release mechanisms in cardiomyocytes, Ca2+ release mediated by ryanodine receptors (RyR2s) and InsP3-induced intracellular Ca2+ release (IP3ICR) remains enigmatic. We aimed at identifying characterizing local IP3ICR events, and elucidating functional local crosstalk mechanisms between cardiac InsP3R2s and RyR2s under conditions of enhanced cardiac specific InsP3R2 activity. Methods and results Using confocal imaging and two-dimensional spark analysis, we demonstrate in atrial myocytes (mouse model cardiac specific overexpressing InsP3R2s) that local Ca2+ release through InsP3Rs (Ca2+ puff) directly activates RyRs and triggers elementary Ca2+ release events (Ca2+ sparks). In the presence of increased intracellular InsP3 concentrations IP3ICR can modulate RyRs openings and Ca2+ spark probability. We show as well that IP3ICR remains under local control of Ca2+ release through RyRs. Conclusions Our results support the concept of bidirectional interaction between RyRs and InsP3Rs (i.e. Ca2+ sparks and Ca2+ puffs) in atrial myocytes. We conclude that highly efficient InsP3 dependent SR-Ca2+ flux constitute the main mechanism of functional crosstalk between InsP3Rs and RyRs resulting in more Ca2+ sensitized RyRs to trigger subsequent Ca2+-induced Ca2+ release activation. In this way, bidirectional local interaction of both SR-Ca2+ release channels may contribute to the shaping of global Ca2+ transients and thereby to contractility in cardiac myocytes.
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MESH Headings
- Animals
- Calcium Signaling/drug effects
- Electric Stimulation
- Endothelin-1/pharmacology
- Heart Atria/metabolism
- Image Processing, Computer-Assisted
- Inositol 1,4,5-Trisphosphate/metabolism
- Inositol 1,4,5-Trisphosphate Receptors/drug effects
- Inositol 1,4,5-Trisphosphate Receptors/genetics
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Mice, Inbred C57BL
- Mice, Transgenic
- Microscopy, Confocal
- Myocardial Contraction
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Phenotype
- Receptor Cross-Talk/drug effects
- Ryanodine Receptor Calcium Release Channel/drug effects
- Ryanodine Receptor Calcium Release Channel/metabolism
- Sarcoplasmic Reticulum/metabolism
- Time Factors
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15
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Zhao QY, Peng YB, Luo XJ, Luo X, Xu H, Wei MY, Jiang QJ, Li WE, Ma LQ, Xu JC, Liu XC, Zang DA, She YS, Zhu H, Shen J, Zhao P, Xue L, Yu MF, Chen W, Zhang P, Fu X, Chen J, Nie X, Shen C, Chen S, Chen S, Chen J, Hu S, Zou C, Qin G, Fang Y, Ding J, Ji G, Zheng YM, Song T, Wang YX, Liu QH. Distinct Effects of Ca 2+ Sparks on Cerebral Artery and Airway Smooth Muscle Cell Tone in Mice and Humans. Int J Biol Sci 2017; 13:1242-1253. [PMID: 29104491 PMCID: PMC5666523 DOI: 10.7150/ijbs.21475] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 08/10/2017] [Indexed: 11/21/2022] Open
Abstract
The effects of Ca2+ sparks on cerebral artery smooth muscle cells (CASMCs) and airway smooth muscle cells (ASMCs) tone, as well as the underlying mechanisms, are not clear. In this investigation, we elucidated the underlying mechanisms of the distinct effects of Ca2+ sparks on cerebral artery smooth muscle cells (CASMCs) and airway smooth muscle cells (ASMCs) tone. In CASMCs, owing to the functional loss of Ca2+-activated Cl- (Clca) channels, Ca2+ sparks activated large-conductance Ca2+-activated K+ channels (BKs), resulting in a decreases in tone against a spontaneous depolarization-caused high tone in the resting state. In ASMCs, Ca2+ sparks induced relaxation through BKs and contraction via Clca channels. However, the integrated result was contraction because Ca2+ sparks activated BKs prior to Clca channels and Clca channels-induced depolarization was larger than BKs-caused hyperpolarization. However, the effects of Ca2+ sparks on both cell types were determined by L-type voltage-dependent Ca2+ channels (LVDCCs). In addition, compared with ASMCs, CASMCs had great and higher amplitude Ca2+ sparks, a higher density of BKs, and higher Ca2+ and voltage sensitivity of BKs. These differences enhanced the ability of Ca2+ sparks to decrease CASMC and to increase ASMC tone. The higher Ca2+ and voltage sensitivity of BKs in CASMCs than ASMCs were determined by the β1 subunits. Moreover, Ca2+ sparks showed the similar effects on human CASMC and ASMC tone. In conclusions, Ca2+ sparks decrease CASMC tone and increase ASMC tone, mediated by BKs and Clca channels, respectively, and finally determined by LVDCCs.
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Affiliation(s)
- Qing-Yang Zhao
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Yong-Bo Peng
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Xiao-Jing Luo
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Xi Luo
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Hao Xu
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Ming-Yu Wei
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Qiu-Ju Jiang
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Wen-Er Li
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Li-Qun Ma
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Jin-Chao Xu
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Xiao-Cao Liu
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Dun-An Zang
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Yu-San She
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - He Zhu
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Jinhua Shen
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Ping Zhao
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Lu Xue
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Meng-Fei Yu
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Weiwei Chen
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
| | - Ping Zhang
- Department of Cerebral Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430032, Hubei, China
| | - Xiangning Fu
- Department of Thoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430032, Hubei, China
| | - Jingyu Chen
- Wuxi &Jiangsu Key Laboratory of Organ Transplantation, Department of Cardiothoracic Surgery, Lung Transplant Group, Wuxi People's Hospital, Nanjing Medical University, Jiangsu, China
| | - Xiaowei Nie
- Wuxi &Jiangsu Key Laboratory of Organ Transplantation, Department of Cardiothoracic Surgery, Lung Transplant Group, Wuxi People's Hospital, Nanjing Medical University, Jiangsu, China
| | - Chenyou Shen
- Wuxi &Jiangsu Key Laboratory of Organ Transplantation, Department of Cardiothoracic Surgery, Lung Transplant Group, Wuxi People's Hospital, Nanjing Medical University, Jiangsu, China
| | - Shu Chen
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430032, Hubei, China
| | - Shanshan Chen
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430032, Hubei, China
| | - Jingcao Chen
- Department of Cerebral Surgery, Zhongnan Hospital, Wuhan University Medical College, Wuhan, 430071, Hubei, China
| | - Sheng Hu
- Department of Medical Oncology, Hubei Cancer Hospital, Wuhan, 430079, Hubei, China
| | - Chunbin Zou
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Gangjian Qin
- Department of Biomedical Engineering, School of Medicine & School of Engineering, University of Alabama Birmingham, AL, 35294, USA
| | - Ying Fang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jiuping Ding
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Guangju Ji
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yun-Min Zheng
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, 12208, USA
| | - Tengyao Song
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, 12208, USA
| | - Yong-Xiao Wang
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, 12208, USA
| | - Qing-Hua Liu
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China
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16
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Popescu I, Galice S, Mohler PJ, Despa S. Elevated local [Ca2+] and CaMKII promote spontaneous Ca2+ release in ankyrin-B-deficient hearts. Cardiovasc Res 2016; 111:287-94. [PMID: 27131508 DOI: 10.1093/cvr/cvw093] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 04/27/2016] [Indexed: 11/13/2022] Open
Abstract
AIMS Loss-of-function mutations in the cytoskeletal protein ankyrin-B (AnkB) cause ventricular tachyarrhythmias in humans. Previously, we found that a larger fraction of the sarcoplasmic reticulum (SR) Ca(2+) leak occurs through Ca(2+) sparks in AnkB-deficient (AnkB(+/-)) mice, which may contribute to arrhythmogenicity via Ca(2+) waves. Here, we investigated the mechanisms responsible for increased Ca(2+) spark frequency in AnkB(+/-) hearts. METHODS AND RESULTS Using immunoblots and phospho-specific antibodies, we found that phosphorylation of ryanodine receptors (RyRs) by CaMKII is enhanced in AnkB(+/-) hearts. In contrast, the PKA-mediated RyR phosphorylation was comparable in AnkB(+/-) and wild-type (WT) mice. CaMKII inhibition greatly reduced Ca(2+) spark frequency in myocytes from AnkB(+/-) mice but had little effect in the WT. Global activities of the major phosphatases PP1 and PP2A were similar in AnkB(+/-) and WT hearts, while CaMKII autophosphorylation, a marker of CaMKII activation, was increased in AnkB(+/-) hearts. Thus, CaMKII-dependent RyR hyperphosphorylation in AnkB(+/-) hearts is caused by augmented CaMKII activity. Intriguingly, CaMKII activation is limited to the sarcolemma-SR junctions since non-junctional CaMKII targets (phospholamban, HDAC4) are not hyperphosphorylated in AnkB(+/-) myocytes. This local CaMKII activation may be the consequence of elevated [Ca(2+)] in the junctional cleft caused by reduced Na(+)/Ca(2+) exchange activity. Indeed, using the RyR-targeted Ca(2+) sensor GCaMP2.2-FBKP12.6, we found that local junctional [Ca(2+)] is significantly elevated in AnkB(+/-) myocytes. CONCLUSIONS The increased incidence of pro-arrhythmogenic Ca(2+) sparks and waves in AnkB(+/-) hearts is due to enhanced CaMKII-mediated RyR phosphorylation, which is caused by higher junctional [Ca(2+)] and consequent local CaMKII activation.
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Affiliation(s)
- Iuliana Popescu
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, 900 S Limestone, Lexington, KY 40536, USA
| | - Samuel Galice
- Department of Pharmacology, University of California Davis, Davis, CA 95616, USA
| | - Peter J Mohler
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Sanda Despa
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, 900 S Limestone, Lexington, KY 40536, USA
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17
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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18
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Delgado C, Ruiz-Hurtado G, Gómez-Hurtado N, González-Ramos S, Rueda A, Benito G, Prieto P, Zaragoza C, Delicado EG, Pérez-Sen R, Miras-Portugal MT, Núñez G, Boscá L, Fernández-Velasco M. NOD1, a new player in cardiac function and calcium handling. Cardiovasc Res 2015; 106:375-86. [PMID: 25824149 DOI: 10.1093/cvr/cvv118] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 03/05/2015] [Indexed: 02/07/2023] Open
Abstract
AIMS Inflammation is a significant contributor to cardiovascular disease and its complications; however, whether the myocardial inflammatory response is harmonized after cardiac injury remains to be determined. Some receptors of the innate immune system, including the nucleotide-binding oligomerization domain-like receptors (NLRs), play key roles in the host response after cardiac damage. Nucleotide-binding oligomerization domain containing 1 (NOD1), a member of the NLR family, is expressed in the heart, but its functional role has not been elucidated. We determine whether selective NOD1 activation modulates cardiac function and Ca(2+) signalling. METHODS AND RESULTS Mice were treated for 3 days with the selective NOD1 agonist C12-iE-DAP (iE-DAP), and cardiac function and Ca(2+) cycling were assessed. We found that iE-DAP treatment resulted in cardiac dysfunction, measured as a decrease in ejection fraction and fractional shortening. Cardiomyocytes isolated from iE-DAP-treated mice displayed a decrease in the L-type Ca(2+) current, [Ca(2+)]i transients and Ca(2+) load, and decreased expression of phospho-phospholamban, sarcoplasmic reticulum-ATPase, and Na(+)-Ca(2+) exchanger. Furthermore, iE-DAP prompted 'diastolic Ca(2+) leak' in cardiomyocytes, resulting from increased Ca(2+) spark frequency and RyR2 over-phosphorylation. Importantly, these iE-DAP-induced changes in Ca(2+) cycling were lost in NOD1(-/-) mice, indicating that iE-DAP exerts its actions through NOD1. Co-treatment of mice with iE-DAP and a selective inhibitor of NF-κB (BAY11-7082) prevented cardiac dysfunction and Ca(2+) handling impairment induced by iE-DAP. CONCLUSION Our data provide the first evidence that NOD1 activation induces cardiac dysfunction associated with excitation-contraction coupling impairment through NF-κB activation and uncover a new pro-inflammatory player in the regulation of cardiovascular function.
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MESH Headings
- Animals
- Anti-Inflammatory Agents/pharmacology
- Calcium/metabolism
- Calcium Channels, L-Type/metabolism
- Calcium-Binding Proteins/metabolism
- Cells, Cultured
- Excitation Contraction Coupling/drug effects
- Inflammation Mediators/agonists
- Inflammation Mediators/antagonists & inhibitors
- Inflammation Mediators/metabolism
- Male
- Membrane Potentials
- Mice, Inbred C57BL
- Mice, Knockout
- Myocardial Contraction/drug effects
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- NF-kappa B/metabolism
- Nod1 Signaling Adaptor Protein/agonists
- Nod1 Signaling Adaptor Protein/antagonists & inhibitors
- Nod1 Signaling Adaptor Protein/deficiency
- Nod1 Signaling Adaptor Protein/genetics
- Nod1 Signaling Adaptor Protein/metabolism
- Phosphorylation
- Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism
- Sodium-Calcium Exchanger/metabolism
- Stroke Volume
- Ventricular Dysfunction, Left/genetics
- Ventricular Dysfunction, Left/metabolism
- Ventricular Dysfunction, Left/physiopathology
- Ventricular Dysfunction, Left/prevention & control
- Ventricular Function, Left/drug effects
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Affiliation(s)
- Carmen Delgado
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Gema Ruiz-Hurtado
- Instituto de Investigación i + 12 Hospital Universitario 12 de Octubre and Instituto Pluridisciplinar, UCM, Madrid, Spain
| | - Nieves Gómez-Hurtado
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Silvia González-Ramos
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | | | - Gemma Benito
- Instituto de Investigación Hospital Universitario La PAZ, IDIPAZ, Madrid, Spain
| | - Patricia Prieto
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Carlos Zaragoza
- Department of Cardiology, University Hospital Ramón y Cajal/University Francisco de Vitoria, Madrid, Spain
| | - Esmerilda G Delicado
- Departamento de Bioquímica y Biología Molecular IV, Facultad de Veterinaria e Instituto Universitario de Investigación en Neuroquímica, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Universidad Complutense, Madrid, Spain
| | - Raquel Pérez-Sen
- Departamento de Bioquímica y Biología Molecular IV, Facultad de Veterinaria e Instituto Universitario de Investigación en Neuroquímica, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Universidad Complutense, Madrid, Spain
| | - Maria Teresa Miras-Portugal
- Departamento de Bioquímica y Biología Molecular IV, Facultad de Veterinaria e Instituto Universitario de Investigación en Neuroquímica, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Universidad Complutense, Madrid, Spain
| | - Gabriel Núñez
- Department of Pathology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Lisardo Boscá
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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19
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Xin W, Li N, Cheng Q, Fernandes VS, Petkov GV. Constitutive PKA activity is essential for maintaining the excitability and contractility in guinea pig urinary bladder smooth muscle: role of the BK channel. Am J Physiol Cell Physiol 2014; 307:C1142-50. [PMID: 25318105 DOI: 10.1152/ajpcell.00167.2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The elevation of protein kinase A (PKA) activity activates the large-conductance voltage- and Ca(2+)-activated K(+) (BK) channels in urinary bladder smooth muscle (UBSM) cells and consequently attenuates spontaneous phasic contractions of UBSM. However, the role of constitutive PKA activity in UBSM function has not been studied. Here, we tested the hypothesis that constitutive PKA activity is essential for controlling the excitability and contractility of UBSM. We used patch clamp electrophysiology, line-scanning confocal and ratiometric fluorescence microscopy on freshly isolated guinea pig UBSM cells, and isometric tension recordings on freshly isolated UBSM strips. Pharmacological inhibition of the constitutive PKA activity with H-89 or PKI 14-22 significantly reduced the frequency and amplitude of spontaneous transient BK channel currents (TBKCs) in UBSM cells. Confocal and ratiometric fluorescence microscopy studies revealed that inhibition of constitutive PKA activity with H-89 reduced the frequency and amplitude of the localized Ca(2+) sparks but increased global Ca(2+) levels and the magnitude of Ca(2+) oscillations in UBSM cells. H-89 abolished the spontaneous transient membrane hyperpolarizations and depolarized the membrane potential in UBSM cells. Inhibition of PKA with H-89 or KT-5720 also increased the amplitude and muscle force of UBSM spontaneous phasic contractions. This study reveals the novel concept that constitutive PKA activity is essential for controlling localized Ca(2+) signals generated by intracellular Ca(2+) stores and cytosolic Ca(2+) levels. Furthermore, constitutive PKA activity is critical for mediating the spontaneous TBKCs in UBSM cells, where it plays a key role in regulating spontaneous phasic contractions in UBSM.
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Affiliation(s)
- Wenkuan Xin
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, South Carolina; and
| | - Ning Li
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, South Carolina; and Department of Urology, Fourth Hospital of China Medical University, Shenyang, China
| | - Qiuping Cheng
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, South Carolina; and
| | - Vitor S Fernandes
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, South Carolina; and
| | - Georgi V Petkov
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, South Carolina; and
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20
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Domeier TL, Roberts CJ, Gibson AK, Hanft LM, McDonald KS, Segal SS. Dantrolene suppresses spontaneous Ca2+ release without altering excitation-contraction coupling in cardiomyocytes of aged mice. Am J Physiol Heart Circ Physiol 2014; 307:H818-29. [PMID: 25038147 DOI: 10.1152/ajpheart.00287.2014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cardiac dysfunction in the aged heart reflects abnormalities in cardiomyocyte Ca(2+) homeostasis including altered Ca(2+) cycling through the sarcoplasmic reticulum (SR). The ryanodine receptor antagonist dantrolene exerts antiarrhythmic effects by preventing spontaneous diastolic Ca(2+) release from the SR. We tested the hypothesis that dantrolene prevents spontaneous Ca(2+) release without altering excitation-contraction coupling in aged myocardium. Left ventricular cardiomyocytes isolated from young (3 to 4 mo) and aged (24-26 mo) C57BL/6 mice were loaded with the Ca(2+) indicator fluo-4. Amplitudes of action potential-induced Ca(2+) transients at 1-Hz pacing were similar between young and aged mice, yet cell shortening was impaired in aged mice. Isoproterenol (1 μM) increased Ca(2+) transient amplitude and cell shortening to identical levels in young and aged; dantrolene (1 μM) had no effect on Ca(2+) transients or cell shortening during pacing. Under Ca(2+) overload conditions induced with 10 mM extracellular Ca(2+) concentration, spontaneous Ca(2+) waves were of diminished amplitude and associated with lower SR Ca(2+) content in aged versus young mice. Despite no effect in young mice, dantrolene increased SR Ca(2+) content and Ca(2+) wave amplitude in aged mice. In the presence of isoproterenol following rest from 1-Hz pacing, Ca(2+) spark frequency was elevated in aged mice, yet the time to spontaneous Ca(2+) wave was similar between young and aged mice; dantrolene decreased Ca(2+) spark frequency and prolonged the time to Ca(2+) wave onset in aged mice with no effect in young mice. Thus dantrolene attenuates diastolic Ca(2+) release in the aged murine heart that may prove useful in preventing cardiac dysfunction.
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Affiliation(s)
- Timothy L Domeier
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri; and
| | - Cale J Roberts
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri; and
| | - Anne K Gibson
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri; and
| | - Laurin M Hanft
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri; and
| | - Kerry S McDonald
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri; and
| | - Steven S Segal
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri; and Dalton Cardiovascular Research Center, University of Missouri School of Medicine, Columbia, Missouri
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21
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Friedrich O, Fink RHA, von Wegner F. New factors contributing to dynamic calcium regulation in the skeletal muscle triad-a crowded place. Biophys Rev 2010; 2:29-38. [PMID: 28509943 PMCID: PMC5425672 DOI: 10.1007/s12551-009-0027-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Accepted: 11/20/2009] [Indexed: 10/20/2022] Open
Abstract
Skeletal muscle is a highly organized tissue that has to be optimized for fast signalling events conveying electrical excitation to contractile response. The site of electro-chemico-mechanical coupling is the skeletal muscle triad where two membrane systems, the extracellular t-tubules and the intracellular sarcoplasmic reticulum, come into very close contact. Structure fits function here and the signalling proteins DHPR and RyR1 were the first to be discovered to bridge this gap in a conformational coupling arrangement. Since then, however, new proteins and more signalling cascades have been identified just in the last decade, adding more diversity and fine tuning to the regulation of excitation-contraction coupling (ECC) and control over Ca2+ store content. The concept of Ca2+ entry into working skeletal muscle has become attractive again with the experimental evidence summarized in this review. Store-operated Ca2+ entry (SOCE), excitation-coupled Ca2+ entry (ECCE), action-potential-activated Ca2+ current (APACC), and retrograde EC-coupling (ECC) are new concepts additional to the conventional orthograde ECC; they have provided fascinating new insights into muscle physiology. In this review, we discuss the discovery of these pathways, their potential roles, and the signalling proteins involved that show that the triad may become a crowded place in time.
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Affiliation(s)
- Oliver Friedrich
- Medical Biophysics, Institute of Physiology & Pathophysiology, University of Heidelberg, INF 326, 69120, Heidelberg, Germany
- School of Biomedical Sciences, University of Queensland, St. Lucia, 4072, Brisbane, QLD, Australia
| | - Rainer H A Fink
- Medical Biophysics, Institute of Physiology & Pathophysiology, University of Heidelberg, INF 326, 69120, Heidelberg, Germany
| | - Frederic von Wegner
- Medical Biophysics, Institute of Physiology & Pathophysiology, University of Heidelberg, INF 326, 69120, Heidelberg, Germany.
- Brain Imaging Center, Goethe University, Schleusenweg 2-16, 60528, Frankfurt a.M., Germany.
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