Analysis of the spatio-temporal distribution of calcium sparks showed a preferential increase in sparks near the sarcolemma in atrial myocytes from patients with atrial fibrillation (AF), linked to higher ryanodine receptor (RyR2) phosphorylation at s2808 and lower calsequestrin-2 levels. Mathematical modeling, incorporating modulation of RyR2 gating, showed that only the observed combinations of RyR2 phosphorylation and calsequestrin-2 levels can account for the spatio-temporal distribution of sparks in patients with and without AF. Furthermore, we demonstrate that preferential calcium release near the sarcolemma is key to a higher incidence and amplitude of afterdepolarizations in atrial myocytes from patients with AF.
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http://dx.doi.org/10.1016/j.jacbts.2022.07.013 | DOI Listing |
Cells
January 2025
Institute of Anatomy & Cell Biology, Faculty of Medicine, Justus-Liebig-University, Aulweg 123, 35392 Giessen, Germany.
Vascular smooth muscle cell (SMC) relaxation by guanylyl cyclases (GCs) and cGMP is mediated by NO and its receptor soluble GC (sGC) or natriuretic peptides (NPs) ANP/BNP and CNP with the receptors GC-A and GC-B, respectively. It is commonly accepted that cultured SMCs differ from those in intact vessels. Nevertheless, cell culture often remains the first step for signaling investigations and drug testing.
View Article and Find Full Text PDFOrphanet J Rare Dis
January 2025
Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, 6-1 Kishibe-Shimmachi, Suita, Osaka, 564-8565, Japan.
Background: Transient receptor potential cation channel subfamily V member 2 (TRPV2) functions as a stretch-sensitive calcium channel, with overexpression in the sarcolemma of skeletal and cardiac myocytes leading to detrimental calcium influx and triggering muscle degeneration. In our previous pilot study, we showed that tranilast, a TRPV2 inhibitor, reduced brain natriuretic peptide levels in two patients with muscular dystrophy and advanced heart failure. Building on this, we performed a single-arm, open-label, multicenter study herein to evaluate the safety and efficacy of tranilast in the treatment of advanced heart failure in patients with muscular dystrophy.
View Article and Find Full Text PDFJ Inorg Biochem
December 2024
Rutgers, The State University of New Jersey, Dept of Pharmacology, Physiology & Neuroscience, Newark, NJ, United States of America.
Crown ethers have been shown to have physiological effects ascribed to their ionophoric properties. However, high levels of toxicity precluded interest in their evaluation as therapeutic agents. We prepared new silacrown analogs of crown ethers.
View Article and Find Full Text PDFKardiologiia
December 2024
Research Institute of Cardiology, Branch of the Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk.
Aim: Comparative assessment of structural changes in cardiomyocyte mitochondria of the right atrial appendage and the mitochondrial respiratory function in peripheral blood leukocytes in a cohort of patients after acute decompensated heart failure (ADHF) and with stable chronic heart failure of ischemic etiology with reduced ejection fraction (CHFrEF) or moderately reduced ejection fraction (CHFmrEF) of the left ventricle.
Material And Methods: The study analyzed 40 micrographs of right atrial appendage cardiomyocytes obtained from 12 patients with CHFrEF and CHFmrEF. The study protocol was registered on ClinicalTrials.
PLoS One
January 2025
Department of Cardiology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China.
Atrial fibrillation (AF) represents the commonly occurring cardiac arrhythmia and the main factor leading to stroke and heart failure. Hydrogen (H2) is a gaseous signaling molecule that has the effects of anti-inflammation and antioxidation. Our study provides evidence that hydrogen decreases susceptibility to AngII-mediated AF together with atrial fibrosis.
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