Objective: To clarify the expression of myocardial cathepsin L and its significance in the pathogenesis of dilated cardiomyopathy (DCM).
Methods: Myocardial tissue specimens derived from 20 patients undergoing orthotopic cardiac transplantation and 5 normal myocardium samples collected at autopsy from sudden death as controls were studied. The expression of cathepsin L was detected with immunohistochemistry, real time PCR and Western Blotting, respectively. At the same time, the relationship between the Cathepsin L mRNA expressional levels and the myocardial function (ejection fraction, EF) was investigated.
Results: The expression levels of cathepsin L mRNA and protein in DCM group were markedly elevated compared with those in control group and the expression levels of cathepsin L mRNA had significantly negative correlation with the myocardial function (ejection fraction, EF).
Conclusion: Cathepsin L is markedly elevated in DCM myocardial tissue and it may participate in the pathogenesis of DCM.