Activation of Wnt/β-catenin/GSK3β signaling during the development of diabetic cardiomyopathy.

Background: As Wnt/β-catenin/glycogen synthase kinase 3β (GSK3β) signaling has been implicated in myocardial injury and diabetic cardiomyopathy (DCM) is a major part of diabetic cardiovascular complications, we therefore investigated the alterations of Wnt/β-catenin/GSK3β signaling during the development of DCM.

Methods: The rat model of diabetes mellitus (DM) was established using a single intraperitoneal injection of streptozotocin (STZ, 60 mg/kg). The alterations of Wnt/β-catenin/GSK3β signaling were determined 4, 8, and 12 weeks following DM using Western blotting, immunohistochemistry, and quantitative real-time reverse transcriptase polymerase chain reaction. Cardiac pathology changes were evaluated using hematoxylin and eosin, Masson trichromatic, and terminal dUTP nick-end labeling staining.

Results: Histological analyses revealed that DM induced significant myocardial injury and progressive cardiomyocyte apoptosis. The protein and mRNA levels of Wnt2, β-catenin, and c-Myc were progressively increased 4, 8, and 12 weeks following DM. The expression of T-cell factor 4 and phosphorylated of GSK3β on Ser9 were progressively increased. However, the expression of the endogenous Wnt inhibitor Dickkopf-1 was increased after STZ injection and then decreased as DCM developed.

Conclusion: Wnt/β-catenin/GSK3β signaling pathway is activated in the development of DCM. Further investigation into the role of Wnt signaling during DCM will functionally find novel therapeutic target for DCM.