Intercalated disk remodeling in δ-sarcoglycan-deficient hamsters fed with an α-linolenic acid-enriched diet

Abstract

Cardiomyocyte intercalated disks of 6-sarcoglycan-deficient cardiomyopathic hamsters (CMPHs) exhibit a pathological accumulation of the N-cadherin/catenin complex. CMPHs fed with an a-linolenic acid (ALA)-enriched diet (CMPH/FS) display an extended longevity compared to those fed with a standard diet (CMPH/PT) owing to, among others, the amelioration of both cardiac tissue structure and myocardial function. The present investigation was aimed at evaluating whether and to what extent the ALA-enriched diet affects the remodeling of CMPH cardiornyocyte intercalated disks and the expression of molecules, including N-cadherin, catenins and connexin 43 (CX43), involved in their organization. Western blot and immunohistochemical analysis demonstrated that the expression of N-cadherin, α- and β-catenin is significantly reduced in cardiomyocyte intercalated disks of CMPH/FS vs. CMPH/PT and is lowered to levels similar to those found in healthy hamsters (GSH/PT), as well as transmission electron microscopy indicated that the cardiomyocyte intercalated disk ultrastructure is also re-established in CMPH/FS. In addition, the delocalization of CX43 as well as the presence of gap junctions were detectable at the lateral plasmamembrane of CMPH/FS cardiomyocytes, while the expression of myocardial CX43 was markedly reduced in both CMPH/PT and CMPH/FS, as compared to GSH/PT. Collectively, the present results demonstrate a substantial effect of an ALA-enriched diet on cardiomyocyte intercalated disk structure and molecular composition and further supports the beneficial effects of ω-3 polyunsatured fatty acids in the prevention of potentially dangerous arrhythmias in cardiac diseases.