Expression and significance of TRAIL and its receptor DR5 in murine myocardium with acute viral myocarditis

Abstract

Objective To deterine the expression of TNF-related apoptosis inducing ligand (TRAIL) and its receptor DR5 in murine myocardium with acute viral myocarditis(VM).Methods We builted the model of VM.Eight mice of the VM group and the normal control group were sacrificed on the 7th,10th,14th,21st,28th day after inoculation CVB3 virus.The myocardial histopathological scores were counted.The terminal reansferase-mediated dUPT-biotin nick end-labeling (TUNEL) assays was used to quantified apoptosis rate.The expression of TRAIL and DR5 protein and mRNA were determined by the method of immunohistochemistry and reverse-transcription polymerase chain reaction (RT-PCR).Results The expression of TRAIL and DR5 protein and mRNA were found in myocardium of both the normal control group and the VM group.The expression of TRAIL protein of the VM group(14th) were significantly higher than which in the normal group at the same time and the VM group(7th)(F=9.17,P<0.01).The DR5 protein of the VM group(10th,14th,21st)were significantly higher than which in the normal group at the same time and the VM group(7th)(F=13.32,P<0.01).The expression of TRAIL and DR5 protein were positive correlated with the myocardial histopathological scores and the apoptosis rate.The expression of TRAIL mRNA of the VM group(10th) were significantly higher than which in the normal group at the same time and the VM group(7th)(F=10.86,P<0.01).The DR5 mRNA of the VM group(10th,14th)were significantly higher than which in the normal group at the same time and the VM group(7th)(F=22.75,P<0.01).Conclusion High characteristic expressions of protein/mRNA TRAIL and DR5 were observed in the myocardium of mice with VM.The level was positive correlationed with the account of pathology and the rate of apoptosis.The apoptosis induced by TRAIL and DR5 may participate in the pathophysiological processes of VM. Key words: Coxsackie virus; Myocarditis; Tunor necrosis factor related apoptosis inducing ligand; Death receptor 5; Apoptosis