Post-Translational Modification of Adiponectin Affects Lipid Accumulation, Proliferation and Migration of Vascular Smooth Muscle Cells
Background/Aims: Adiponectin (Apn) is a multifunctional adipokine that circulates as several oligomeric complexes in the blood stream. Previous reports showed that several conserved lysine residues within the N-terminal collagenous domain of Apn are modified by hydroxylation and glycosylation. Here, we investigated the potential roles of post-translational modifications of Apn on the function of human vascular smooth muscle cells (VSMCs). Methods: Blood samples of 92 coronary artery disease (CAD) patients and 20 healthy volunteers were collected and total and high molecular weight (HMW) Apn concentration and glycosylation were analyzed. Results: The results revealed that total and HMW Apn derived from blood samples of CAD patients with severe stenosis significantly increased, however the glycosylation of HMW Apn significantly decreased. Functional studies of human VSMCs revealed that glycosylated Apn significantly inhibited the oxidized LDL-induced lipid accumulation, proliferation and migration of VSMCs, whereas non-glycosylated Apn had no inhibitory effects. Conclusion: Taken together, these data suggest that glycosylation of Apn is critically involved in regulating function against atherosclerosis by inhibiting lipid accumulation and proliferation and migration of VSMCs.