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stretch channels cardiac

Maria João Marques-Carvalho, Johannes Oppermann, Eva Muñoz, Andreia S Fernandes, Guillaume Gabant, Martine Cadene, Stefan H Heinemann, Roland Schönherr, João Henrique Morais-Cabral
The human EAG1 potassium channel belongs to the superfamily of KCNH voltage-gated potassium channels that have roles in cardiac repolarization and neuronal excitability. EAG1 is strongly inhibited by Ca(2+)/calmodulin (CaM) through a mechanism that is not understood. We determined the binding properties of CaM with each one of three previously identified binding sites (BDN, BDC1, and BDC2), analyzed binding to protein stretches that include more than one site, and determined the effect of neighboring globular domains on the binding properties...
October 4, 2016: Structure
V Kazanski, V M Mitrokhin, M I Mladenov, A G Kamkin
: The role of cytokines as regulators of stretch-related mechanisms is of special importance since mechano-sensitivity plays an important role in a wide variety of biological processes. Here, we elucidate the influence of cytokine application on mechano-sensitivity and mechano-transduction. The atrial myocardial stretch induces production of interleukin (IL)-2, IL-6, IL-13, IL-17A, and IL-18 with exception of tumor necrosis factor α (TNF-α), IL-1β, and vascular endothelial growth factor B (VEGF-B)...
September 12, 2016: Immunological Investigations
Yen-Yu Lu, Yung-Kuo Lin, Yu-Hsun Kao, Cheng-Chih Chung, Yung-Hsin Yeh, Shih-Ann Chen, Yi-Jen Chen
The extracellular matrix (ECM) and transforming growth factor-β (TGF)-β are important in cardiac fibrosis, however, the effects of the ECM on TGF‑β signaling remain to be fully elucidated. The aims of the present study were to evaluate the role of collagen in TGF‑β signaling and examine the underlying mechanisms. In the present study, western blot analysis was used to examine TGF‑β signaling in HL‑1 cells treated with and without (control) type I collagen (10 µg/ml), which was co‑administered with either an anti‑β1 integrin antibody (10 µg/ml) or a stretch‑activated channel inhibitor (gadolinium; 50 µM)...
October 2016: Molecular Medicine Reports
P Colli Franzone, L F Pavarino, S Scacchi
The aim of this work is to investigate, by means of numerical simulations, the influence of myocardial deformation due to muscle contraction and relaxation on the cardiac repolarization process in presence of transmural intrinsic action potential duration (APD) heterogeneities. The three-dimensional electromechanical model considered consists of the following four coupled components: the quasi-static transversely isotropic finite elasticity equations for the deformation of the cardiac tissue; the active tension model for the intracellular calcium dynamics and cross-bridge binding; the anisotropic Bidomain model for the electrical current flow through the deforming cardiac tissue; the membrane model of ventricular myocytes, including stretch-activated channels...
October 2016: Mathematical Biosciences
Drielen de Oliveira Moreira, Humberto Santo Neto, Maria Julia Marques
INTRODUCTION: In Duchenne muscular dystrophy (DMD) and in the mdx mouse model of DMD, the lack of dystrophin leads to increased calcium influx and muscle necrosis. Patients suffer progressive muscle loss, and cardiomyopathy is an important determinant of morbidity. P2 purinergic receptors participate in the increased calcium levels in dystrophic skeletal muscles. In this study, we evaluated whether P2 receptors are involved in cardiomyopathy in mdx mice at later stages of the disease...
May 24, 2016: Muscle & Nerve
Bernardo L de Oliveira, Emily R Pfeiffer, Joakim Sundnes, Samuel T Wall, Andrew D McCulloch
Volume loading of the cardiac ventricles is known to slow electrical conduction in the rabbit heart, but the mechanisms remain unclear. Previous experimental and modeling studies have investigated some of these mechanisms, including stretch-activated membrane currents, reduced gap junctional conductance, and altered cell membrane capacitance. In order to quantify the relative contributions of these mechanisms, we combined a monomain model of rabbit ventricular electrophysiology with a hyperelastic model of passive ventricular mechanics...
June 1, 2015: Cellular and Molecular Bioengineering
Tobias Glück, Peter Alter
Therapeutic implications of marine omega-3 highly unsaturated fatty acids (HUFA) in cardiovascular disease are still discussed controversially. Several clinical trials report divergent findings and thus leave ambiguity on the meaning of oral omega-3 therapy. Potential prognostic indications of HUFA treatment have been predominantly studied in coronary artery disease, sudden cardiac death, ventricular arrhythmias, atrial fibrillation and heart failure of various origin. It is suspected that increased ventricular wall stress is crucially involved in the prognosis of heart failure...
July 2016: Vascular Pharmacology
Jan-Christoph Edelmann, Lizzie Jones, Remi Peyronnet, Liang Lu, Peter Kohl, Ursula Ravens
Cells residing in the cardiac niche are constantly experiencing physical stimuli, including electrical pulses and cyclic mechanical stretch. These physical signals are known to influence a variety of cell functions, including the secretion of growth factors and extracellular matrix proteins by cardiac fibroblasts, calcium handling and contractility in cardiomyocytes, or stretch-activated ion channels in muscle and non-muscle cells of the cardiovascular system. Recent progress in cardiac tissue engineering suggests that controlled physical stimulation can lead to functional improvements in multicellular cardiac tissue constructs...
2016: Methods in Molecular Biology
Rémi Peyronnet, Jeanne M Nerbonne, Peter Kohl
Mechanical forces will have been omnipresent since the origin of life, and living organisms have evolved mechanisms to sense, interpret, and respond to mechanical stimuli. The cardiovascular system in general, and the heart in particular, is exposed to constantly changing mechanical signals, including stretch, compression, bending, and shear. The heart adjusts its performance to the mechanical environment, modifying electrical, mechanical, metabolic, and structural properties over a range of time scales. Many of the underlying regulatory processes are encoded intracardially and are, thus, maintained even in heart transplant recipients...
January 22, 2016: Circulation Research
E Aguettaz, J J Lopez, A Krzesiak, L Lipskaia, S Adnot, R J Hajjar, C Cognard, B Constantin, S Sebille
In Duchenne muscular dystrophy (DMD), deficiency of the cytoskeletal protein dystrophin leads to well-described defects in skeletal muscle but also to dilated cardiomyopathy (DCM). In cardiac cells, the subsarcolemmal localization of dystrophin is thought to protect the membrane from mechanical stress. The dystrophin deficiency leads to membrane instability and a high stress-induced Ca(2+) influx due to dysregulation of sarcolemmal channels such as stretch-activated channels (SACs). In this work divalent cation entry has been explored in isolated ventricular Wild Type (WT) and mdx cardiomyocytes in two different conditions: at rest and during the application of an axial stretch...
April 2016: Cell Calcium
Jipeng Maa, Lifang Yang, Yanyan Maa, Xiaowu Wang, Jun Ren, Jian Yang
Cardiovascular disease is still the most frequent cause of death in both developed and developing countries while metabolic syndrome and myocardial ischemia reperfusion (I/R) injury are the common risk factors responsible for the impaired cardiac function. Transient receptor potential (TRP) channels are non-selective cation channels and sense a broad range of stimuli from physical conditions such as stretch to chemicals including capsaicin. The diverse studies have revealed multifunctional roles of TRP channels in the physiological conditions and various diseases while some members of TRP channel superfamily are demonstrated to participate in the pathophysiology of cardiometabolic diseases and myocardial ischemia reperfusion injury...
October 18, 2015: Current Drug Targets
Joon-Chul Kim, Sun-Hee Woo
Atrial myocytes are exposed to shear stress during the cardiac cycle and haemodynamic disturbance. In response, they generate a longitudinally propagating global Ca(2+) wave. Here, we investigated the cellular mechanisms underlying the shear stress-mediated Ca(2+) wave, using two-dimensional confocal Ca(2+) imaging combined with a pressurized microflow system in single rat atrial myocytes. Shear stress of ∼16 dyn cm(-2) for 8 s induced ∼1.2 aperiodic longitudinal Ca(2+) waves (∼79 μm s(-1)) with a delay of 0...
December 1, 2015: Journal of Physiology
Mindi Naticchioni, Rajiv Karani, Margaret A Smith, Evan Onusko, Nathan Robbins, Min Jiang, Tatiana Radzyukevich, Logan Fulford, Xu Gao, Ryan Apel, Judith Heiny, Jack Rubinstein, Sheryl E Koch
The myocardial response to exercise is an adaptive mechanism that permits the heart to maintain cardiac output via improved cardiac function and development of hypertrophy. There are many overlapping mechanisms via which this occurs with calcium handling being a crucial component of this process. Our laboratory has previously found that the stretch sensitive TRPV2 channels are active regulators of calcium handling and cardiac function under baseline conditions based on our observations that TRPV2-KO mice have impaired cardiac function at baseline...
2015: PloS One
Samhita S Rhodes, Amadou K S Camara, Mohammed Aldakkak, James S Heisner, David F Stowe
Stretching the cardiac left ventricle (LV) enhances contractility but its effect on myoplasmic [Ca(2+)] is controversial. We measured LV pressure (LVP) and [Ca(2+)] as a function of intra-LV stretch in guinea pig intact hearts before and after 15 min global stunning ± perfusion with streptomycin (STM), a stretch-activated channel blocker. LV wall [Ca(2+)] was measured by indo-1 fluorescence and LVP by a saline-filled latex balloon inflated in 50 μL steps to stretch the LV. We implemented a mathematical model to interpret cross-bridge dynamics and myofilament Ca(2+) responsiveness from the instantaneous relationship between [Ca(2+)] and LVP ± stretching...
August 2015: Physiological Reports
Yan Qi, Zhichao Li, Chi-Wing Kong, Nelson L Tang, Yu Huang, Ronald A Li, Xiaoqiang Yao
Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) in culture are randomly organized and do not typically show directional alignment. In the present study, we used uniaxial cyclic stretch to facilitate the alignment of cultured human embryonic stem cell-derived cardiomyocytes (hESC-CMs), so that these cells can be more adult-like for potential future application in drug screening and in vitro studies of cardiac function. We then explored the functional role of mechanosensitive TRPV4 channels in cyclic stretch-induced realignment of hESC-CMs...
October 2015: Journal of Molecular and Cellular Cardiology
Beata Franczyk-Skóra, Anna Gluba-Brzózka, Jerzy Krzysztof Wranicz, Maciej Banach, Robert Olszewski, Jacek Rysz
The risk of sudden cardiac death (SCD) is high in chronic kidney disease patients, and it increases with the progression of kidney function deterioration. The most common causes of SDC are the following: ventricular tachycardia, ventricular tachyarrhythmia, tachycardia torsade de pointes, sustained ventricular fibrillation and bradyarrhythmia. Dialysis influences cardiovascular system and results in hemodynamic disturbances as well as electrolyte shifts altering myocardial electrophysiology. Studies suggest that this procedure exerts both detrimental (poor volume control can exacerbate hypertension and left ventricle hypertrophy) and beneficial effects (associated with fluid removal and subsequent decrease in left ventricle stretch)...
June 2015: International Urology and Nephrology
Zully Pedrozo, Alfredo Criollo, Pavan K Battiprolu, Cyndi R Morales, Ariel Contreras-Ferrat, Carolina Fernández, Nan Jiang, Xiang Luo, Michael J Caplan, Stefan Somlo, Beverly A Rothermel, Thomas G Gillette, Sergio Lavandero, Joseph A Hill
BACKGROUND: L-type calcium channel activity is critical to afterload-induced hypertrophic growth of the heart. However, the mechanisms governing mechanical stress-induced activation of L-type calcium channel activity are obscure. Polycystin-1 (PC-1) is a G protein-coupled receptor-like protein that functions as a mechanosensor in a variety of cell types and is present in cardiomyocytes. METHODS AND RESULTS: We subjected neonatal rat ventricular myocytes to mechanical stretch by exposing them to hypo-osmotic medium or cyclic mechanical stretch, triggering cell growth in a manner dependent on L-type calcium channel activity...
June 16, 2015: Circulation
Shampa Chatterjee, Keigi Fujiwara, Néstor Gustavo Pérez, Masuko Ushio-Fukai, Aron B Fisher
Cells are constantly exposed to mechanical forces that play a role in modulating cellular structure and function. The cardiovascular system experiences physical forces in the form of shear stress and stretch associated with blood flow and contraction, respectively. These forces are sensed by endothelial cells and cardiomyocytes and lead to responses that control vascular and cardiac homeostasis. This was highlighted at the Pan American Physiological Society meeting at Iguassu Falls, Brazil, in a symposium titled "Mechanosignaling in the Vasculature...
June 15, 2015: American Journal of Physiology. Heart and Circulatory Physiology
Charlotte Lorin, Isabelle Vögeli, Ernst Niggli
AIMS: Duchenne muscular dystrophy (DMD), a degenerative pathology of skeletal muscle, also induces cardiac failure and arrhythmias due to a mutation leading to the lack of the protein dystrophin. In cardiac cells, the subsarcolemmal localization of dystrophin is thought to protect the membrane from mechanical stress. The absence of dystrophin results in an elevated stress-induced Ca2+ influx due to the inadequate functioning of several proteins, such as stretch-activated channels (SACs)...
April 1, 2015: Cardiovascular Research
Alistair Reed, Peter Kohl, Rémi Peyronnet
The heart is a mechanically-active organ that dynamically senses its own mechanical environment. This environment is constantly changing, on a beat-by-beat basis, with additional modulation by respiratory activity and changes in posture or physical activity, and further overlaid with more slowly occurring physiological (e.g. pregnancy, endurance training) or pathological challenges (e.g. pressure or volume overload). Far from being a simple pump, the heart detects changes in mechanical demand and adjusts its performance accordingly, both via heart rate and stroke volume alteration...
2014: Global Cardiology Science & Practice
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