Role of cardiac TBX20 in dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) is an important cause of heart failure and sudden cardiac death worldwide. Transcription factor TBX20 has been shown to play a crucial role in cardiac development and maintenance of adult mouse heart. Recent studies suggest that TBX20 may have a role in pathophysiology of DCM. In the present study, we examined TBX20 expression in idiopathic DCM patients and in an animal model of cardiomyopathy, and studied its correlation with echocardiographic indices of LV function. Endomyocardial biopsies (EMBs) from intraventricular septal from the right ventricle region were obtained from idiopathic DCM patients (IDCM, n = 30) and from patients with ventricular septal defect (VSD, n = 14) with normal LVEF who served as controls. An animal model of DCM was developed by right renal artery ligation in Wistar rats. Cardiac TBX20 mRNA levels were measured by real-time PCR in IDCM, controls, and in rats. The role of DNA promoter methylation and copy number variation (CNVs) in regulating TBX20 gene expression was also investigated. Cardiac TBX20 mRNA levels were significantly increased (8.9 fold, p < 0.001) in IDCM patients and in RAL rats as compared to the control group. Cardiac TBX20 expression showed a negative correlation with LVEF (r = -0.71, p < 0.001) and a positive correlation with left ventricular end-systolic volume (r = 0.39, p = 0.038). No significant difference in TBX20 CNVs and promoter methylation was observed between IDCM patients and control group. Our results suggest a potential role of TBX20 in pathophysiology of DCM.