Adiponectin suppresses inflammatory responses at the early phase of atherosclerosis in hyperglycemic rats

Adiponectin plays an important role in atherosclerosis, but its relationship with the early initiation of atherosclerosis in diabetes mellitus is still not completely understood. In this study, we defined the role of adiponectin early in the process of atherosclerosis in hyperglycemic rats. Recombinant adenovirus expressing the full-length apM1 cDNA gene (Ad-APN) was constructed and successfully transfected into hyperglycemic rats characterized by the presentation of early atherosclerosis. The levels of sICAM-1 and C-reactive protein (CRP) in serum as well as the expression of VCAM-1, ICAM-1 and MCP-1 in aortic tissue were evaluated. Serum adiponectin was significantly increased in Ad-APN-treated rats compared with Ad-βgal-treated rats. The levels of sICAM-1 and CRP in serum were dramatically reduced by 22 and 21%, respectively, in Ad-APN-treated rats. Additionally, in aortic tissue, significantly reduced mRNA levels of VCAM-1, ICAM-1 and MCP-1 were observed after Ad-APN transfection. These results suggest that, in hyperglycemic rats, adiponectin plays an inhibitory role in the early development of atherosclerosis. In conclusion, the protective effect of adiponectin is associated with the reduced activity of various inflammation-related factors.