Transient receptor potential channels contribute to pathological structural and functional remodeling after myocardial infarction (original) (raw)

TRPC channels: Dysregulation and Ca2+ Mishandling In Ischemic Heart Disease

Transient receptor potential canonical (TRPC) channels are ubiquitously expressed in excitable and non-excitable cardiac cells where they sense and respond to a wide variety of physical and chemical stimuli. As other TRP, TRPC may form homo or heterotetrameric ion channel, and they can associate with other membrane receptors and ion channels to regulate intracellular calcium concentration. Dysfunctions of TRPC channels are involved in many types of cardiovascular diseases. Significant increase of the expression of different TRPC isoforms has been observed in different animal model of heart infarcts, and in vitro experimental model of ischemia and reperfusion. TRPC-mediated increase of the intracellular Ca2+ concentration seems required for the activation of signaling pathway that plays minor roles in the healthy heart, but they are more relevant for cardiac responses to ischemia, such as the activation of different factors of transcription and cardiac hypertrophy, fibrosis, and angi...

TRP Channels: Current Perspectives in the Adverse Cardiac Remodeling

Frontiers in Physiology

Calcium is an important second messenger required not only for the excitation-contraction coupling of the heart but also critical for the activation of cell signaling pathways involved in the adverse cardiac remodeling and consequently for the heart failure. Sustained neurohumoral activation, pressure-overload, or myocardial injury can cause pathologic hypertrophic growth of the heart followed by interstitial fibrosis. The consequent heart's structural and molecular adaptation might elevate the risk of developing heart failure and malignant arrhythmia. Compelling evidences have demonstrated that Ca 2+ entry through TRP channels might play pivotal roles in cardiac function and pathology. TRP proteins are classified into six subfamilies: TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPA (ankyrin), TRPML (mucolipin), and TRPP (polycystin), which are activated by numerous physical and/or chemical stimuli. TRP channels participate to the handling of the intracellular Ca 2+ concentration in cardiac myocytes and are mediators of different cardiovascular alterations. This review provides an overview of the current knowledge of TRP proteins implication in the pathologic process of some frequent cardiac diseases associated with the adverse cardiac remodeling such as cardiac hypertrophy, fibrosis, and conduction alteration.

Major contribution of the 3/6/7 class of TRPC channels to myocardial ischemia/reperfusion and cellular hypoxia/reoxygenation injuries

Proceedings of the National Academy of Sciences of the United States of America, 2017

The injury phase after myocardial infarcts occurs during reperfusion and is a consequence of calcium release from internal stores combined with calcium entry, leading to cell death by apoptopic and necrotic processes. The mechanism(s) by which calcium enters cells has(ve) not been identified. Here, we identify canonical transient receptor potential channels (TRPC) 3 and 6 as the cation channels through which most of the damaging calcium enters cells to trigger their death, and we describe mechanisms activated during the injury phase. Working in vitro with H9c2 cardiomyoblasts subjected to 9-h hypoxia followed by 6-h reoxygenation (H/R), and analyzing changes occurring in areas-at-risk (AARs) of murine hearts subjected to a 30-min ischemia followed by 24-h reperfusion (I/R) protocol, we found: (i) that blocking TRPC with SKF96365 significantly ameliorated damage induced by H/R, including development of the mitochondrial permeability transition and proapoptotic changes in Bcl2/BAX rat...

TRPC1 Channels Are Critical for Hypertrophic Signaling in the Heart

Circulation Research, 2009

Rationale: Cardiac muscle adapts to increase workload by altering cardiomyocyte size and function resulting in cardiac hypertrophy. G protein-coupled receptor signaling is known to govern the hypertrophic response through the regulation of ion channel activity and downstream signaling in failing cardiomyocytes. Objective: Transient receptor potential canonical (TRPC) channels are G protein-coupled receptor operated channels previously implicated in cardiac hypertrophy. Our objective of this study is to better understand how TRPC channels influence cardiomyocyte calcium signaling. Methods and Results: Here, we used whole cell patch clamp of adult cardiomyocytes to show upregulation of a nonselective cation current reminiscent of TRPC channels subjected to pressure overload. This TRPC current corresponds to the increased TRPC channel expression noted in hearts of mice subjected to pressure overload. Importantly, we show that mice lacking TRPC1 channels are missing this putative TRPC current. Moreover, Trpc1 ؊/؊ mice fail to manifest evidence of maladaptive cardiac hypertrophy and maintain preserved cardiac function when subjected to hemodynamic stress and neurohormonal excess. In addition, we provide a mechanistic basis for the protection conferred to Trpc1 ؊/؊ mice as mechanosensitive signaling through calcineurin/NFAT, mTOR and Akt is altered in Trpc1 ؊/؊ mice. Conclusions: From these studies, we suggest that TRPC1 channels are critical for the adaptation to biomechanical stress and TRPC dysregulation leads to maladaptive cardiac hypertrophy and failure.

Location and function of transient receptor potential canonical channel 1 in ventricular myocytes

Journal of Molecular and Cellular Cardiology, 2020

Transient receptor potential canonical 1 (TRPC1) protein is abundantly expressed in cardiomyocytes. While TRPC1 is supposed to be critically involved in cardiac hypertrophy, its physiological role in cardiomyocytes is poorly understood. We investigated the subcellular location of TRPC1 and its contribution to Ca 2+ signaling in mammalian ventricular myocytes. Immunolabeling, three-dimensional scanning confocal microscopy and quantitative colocalization analysis revealed an abundant intracellular location of TRPC1 in neonatal rat ventricular myocytes (NRVM) and adult rabbit ventricular myocytes. TRPC1 was colocalized with intracellular proteins including sarco/endoplasmic reticulum Ca 2+ ATPase 2 in the sarcoplasmic reticulum (SR). Colocalization with wheat germ agglutinin, which labels the glycocalyx and thus marks the sarcolemma including the transverse tubular system, was low. Super-resolution and immunoelectron microscopy supported the intracellular location of TRPC1. We investigated Ca 2+ signaling in NRVMs after adenoviral TRPC1 overexpression or silencing. In NRVMs bathed in Na + and Ca 2+ free solution, TRPC1 overexpression and silencing was associated with a decreased and increased SR Ca 2+ content, respectively. In isolated rabbit cardiomyocytes bathed in Na + and

Transient Receptor Potential Channels in Cardiovascular Function and Disease

Circulation Research, 2006

Sustained elevation in the intracellular Ca 2+ concentration via Ca 2+ influx, which is activated by a variety of mechanisms, plays a central regulatory role for cardiovascular functions. Recent molecular biological research has disclosed an unexpectedly diverse array of Ca 2+ -entry channel molecules involved in this Ca 2+ influx. These include more than ten transient receptor potential (TRP) superfamily members such as TRPC1, TRPC3–6, TRPV1, TRPV2, TRPV4, TRPM4, TRPM7, and polycystin (TRPP2). Most of them appear to be multimodally activated or modulated and show relevant features to both acute hemodynamic control and long-term remodeling of the cardiovascular system, and many of them have been found to respond not only to receptor stimulation but also to various forms of stimuli. There is good evidence to implicate TRPC1 in neointimal hyperplasia after vascular injury via store-depletion–operated Ca 2+ entry. TRPC6 likely contributes to receptor-operated and mechanosensitive Ca 2+...

A background Ca2+ entry pathway mediated by TRPC1/TRPC4 is critical for development of pathological cardiac remodelling

European heart journal, 2015

Pathological cardiac hypertrophy is a major predictor for the development of cardiac diseases. It is associated with chronic neurohumoral stimulation and with altered cardiac Ca(2+) signalling in cardiomyocytes. TRPC proteins form agonist-induced cation channels, but their functional role for Ca(2+) homeostasis in cardiomyocytes during fast cytosolic Ca(2+) cycling and neurohumoral stimulation leading to hypertrophy is unknown. In a systematic analysis of multiple knockout mice using fluorescence imaging of electrically paced adult ventricular cardiomyocytes and Mn(2+)-quench microfluorimetry, we identified a background Ca(2+) entry (BGCE) pathway that critically depends on TRPC1/C4 proteins but not others such as TRPC3/C6. Reduction of BGCE in TRPC1/C4-deficient cardiomyocytes lowers diastolic and systolic Ca(2+) concentrations both, under basal conditions and under neurohumoral stimulation without affecting cardiac contractility measured in isolated hearts and in vivo. Neurohumora...

The second member of transient receptor potential-melastatin channel family protects hearts from ischemia-reperfusion injury

American Journal of Physiology-Heart and Circulatory Physiology, 2013

The second member of the transient receptor potential-melastatin channel family (TRPM2) is expressed in the heart and vasculature. TRPM2 channels were expressed in the sarcolemma and transverse tubules of adult left ventricular (LV) myocytes. Cardiac TRPM2 channels were functional since activation with H2O2 resulted in Ca2+ influx that was dependent on extracellular Ca2+, was significantly higher in wild-type (WT) myocytes compared with TRPM2 knockout (KO) myocytes, and inhibited by clotrimazole in WT myocytes. At rest, there were no differences in LV mass, heart rate, fractional shortening, and +dP/d t between WT and KO hearts. At 2–3 days after ischemia-reperfusion (I/R), despite similar areas at risk and infarct sizes, KO hearts had lower fractional shortening and +dP/d t compared with WT hearts. Compared with WT I/R myocytes, expression of the Na+/Ca2+ exchanger (NCX1) and NCX1 current were increased, expression of the α1-subunit of Na+-K+-ATPase and Na+ pump current were decrea...