Alterations in Intercalated Disk Proteins Contribute to the Development of Lethal Arrhythmias

点击翻译按钮获取中文摘要

The intercalated disc (ID) contains adhesion junctions (AJs) and connexin (Cx) gap junctions (GJs). We investigated ID remodeling during development of heart failure in UM-X7.1 cardiomyopathic hamsters (UMX). We investigated the effect of angiotensin II blockade (ARB) on ID remodeling. At 10w, ~20% of UMX died suddenly, and VT/VF was inducible in ~30%. At 10w, the dispersion of action potential duration (APD) was increased. At 20w showed significant reduction of cardiac space constant, a decrease in conduction velocity, and an increase in APD dispersion. The expression of Cx43 was reduced and Ser255-phosphorylated Cx43 was increased at 20w. Qualitative and quantitative Cx43 alterations create serious arrhythmogenic substrate. The changes in beta-catenin preceded Cx43 alterations. At 10w, the nuclear expression of beta-catenin was remarkably decreased. ARB improved these alterations in ID proteins and physiological properties. ARB was an effective treatment of ID remodeling.