Protein O-glycosylation induces collagen expression and contributes to diabetic cardiomyopathy in rat cardiac fibroblasts.

Diabetic cardiomyopathy may be accompanied by myocardial fibrosis. We have previously reported that cardiac fibrosis and protein O-glycosylation are elevated in diabetes. In this study, we examined if the hexosamine biosynthesis pathway (HBP) was involved with collagen expression in rat cardiac fibroblasts (RCFs). Long-term glucose load significantly increased type III collagen expression in RCFs, but did not affect the protein O-glycosylation. In addition, glucosamine treatment not only induced expressions of collagen types I and III, but also increased the O-glycosylated protein. These results suggest that O-glycosylation of protein induced by HBP activation modifies collagen expression and contributes to diabetic cardiomyopathy.