ABSTRACT
Autoimmune is involved in the pathogenesis of ventricular remodeling in acute myocardial infarction (AMI). In the present study, we investigated the effect of anti-cardiac myosin heavy chain antibodies (AMHCA) from patients with AMI on rat cardiomyocyte apoptosis. Cardiomyocyte apoptosis was observed and measured by DNA end labeling and Annexin- V/PI double-staining assay.The expression of apoptosis related p53 and Bcl-2 protein and the second messenger calcium were detected respectively by Western blotting, patch clamp and confocal calcium imaging. The results showed that AMHCA was able to induce cardiomyocyte apoptosis in a dose dependent manner.Apoptosis-accelerating nucleoprotein p53 was up-regulated, while apoptosis-inhibiting cytoplasmic protein Bcl-2 was down-regulated. In parallel, cytoplasmic calcium concentration was elevated.There was no effect on L-type calcium currents. It is concluded that AMHCA in patients with AMI as a novel triggering factor can induce cardiomyocyte apoptosis, which contributes to ventricular remodeling.