Role Of Corin In Pathogenesis Of Diabetic Cardiomyopathy

Objective With diabetes mellitus(DM) increasing, its complications are paid great attention. Diabetic cardiomyopathy(DCM) is one of the major cardiac complications of diabetes mellitus patients and also is the leading cause of death. However, to date, knowledge in the pathogenesis of DCM is still limited. Vascular remodeling is the pathophysiologic basis of diabetic cardiomyopathy. Corin, a cardiac protease, is highly specific for converting pro-atrial natriuretic peptide(pro-ANP) to biologically active atrial natriuretic peptide(ANP). Moreover, our previous study showed that Corin was associated with vascular remodeling. This study creates high glucose-induced H9c2 cardiomyoblasts in vitro through the related molecular biology technology and aims to investigate the role of Corin in the pathogenesis of diabetic cardiomyopathy. We expect to provide new perspectives and therapeutic targets for the prevention and control of DCM. Methods 1. Real-time PCR detected Corin expression in m RNA level in high glucose-induced H9c2 cardiomyoblasts. 2. Immunofluorescence staining detected Corin expression level in high glucose-induced H9c2 cardiomyoblasts. 3. Real-time PCR detected CORIN silencing efficiency in Corin-si RNA H9c2 cardiomyoblasts. 4. Western blot detected CORIN silencing efficiency in Corin-si RNA H9c2 cardiomyoblasts. 5. Optical microscope observed Corin-si RNA H9c2 cardiomyoblasts proliferation. 6. MTT colorimetry and trypan blue staining detected cell vitality of Corin-si RNA H9c2 cardiomyoblasts. 7. The endothelial cell scratching test detected the effect of supernatant of Corin-si RNA H9c2 cardiomyoblasts on EA. hy926 endothelial cells. 8. We detected the random blood glucose and body weight of type 1 diabetes cardiomyopathy rat animal model; echocardiography monitored configuration and function change of the type 1 diabetes cardiomyopathy rat animal model, including left ventricular internal dimension in diastole(LVIDd), diastolic interventricular septal wall thickness(IVSd), left ventricular posterior wall thickness in diastole(LVPWd), left ventricular internal dimension in systole(LVIDs), systolic interventricular septal wall thickness(IVSs), left ventricular posterior wall thickness in systole(LVPWs), left ventricular fractional fraction(% FS), left ventricular ejection fraction(EF), mitral diastolic velocity E/A ratio.9. Immunofluorescence staining detected cardiac iso-lectin B4 expression in diabetes cardiomyopathy(DCM) rats. Results 1. Real-time PCR showed that in high glucose-induced H9c2 cardiomyoblasts, Corin expression in m RNA level decreased significantly compared with those in the Ctrl group(P < 0.01). 2. Immunofluorescence staining showed that in high glucose-induced H9c2 cardiomyoblasts, Corin expression in protein level was reduced significantly compared with those in the Ctrl and OC groups. 3. Real-time PCR detected that the silencing efficiency of Corin-si RNA sequence 1 and sequence 2 in H9c2 cardiomyoblasts are 55.86% and 54.71% respectively(P < 0.01). 4. Western blot showed that in Corin-si RNA sequences 1 and sequence 2 H9c2 cardiomyoblasts, Corin expression in protein level decreased obviously when compared with NC-si RNA group. 5. Optical microscope observed that Corin-si RNA H9c2 cardiomyoblasts proliferation was significantly inhibited when compared with NC-si RNA group. 6. MTT colorimetry and trypan blue staining showed that cell count and cell viability decreased obviously in Corin-si RNA H9c2 cardiomyoblasts in comparison to that in NC-si RNA group(P < 0.01). 7. The endothelial cell scratching test detected that Corin-si RNA H9c2 cardiomyoblasts inhibited repair after EA. hy926 endothelial cells damage.8. Compared with that in control group, random blood glucose in DCM group was increased significantly(P < 0.01), body weight was significantly decreased(P < 0.01). Echocardiography showed that LVIDs was increased significantly(P < 0.01), IVSs and LVPWs was decreased significantly(P < 0.01), % FS and EF in DCM group were significantly decreased(P < 0.01), while IVSd was reduced(P < 0.05), LVIDd and LVPWd was decreased significantly(P < 0.01), E/A ratio in DCM group had no difference(P > 0.05), in comparison to that in the control group. 9. Immunofluorescence staining indicated that cardiac iso-lectin B4 expression was obviously decreased in DCM groups, when compared with that in the control group(P < 0.01). Conclusions 1. Construct the Corin-si RNA H9c2 cardiomyoblasts model successfully; 2. Corin has the cardioprotective effect; 3. Lack of Corin affects the function of endothelial cell repair after damage; 4. Corin deficiency plays an important role in vascular remodeling and endothelial injury of diabetic cardiomyopathy; 5. Corin plays a significant role in the pathogenesis of diabetic cardiomyopathy.