GW24-e3510 Mechanism of inhibitory effects of C-phycocyanin on over proliferation of vascular smooth muscle cells and luminal stenosis

Objectives To investigate the effects and mechanism of C-phycocyanin (C-PC) from Spirulina Platensis on over proliferation of vascular smooth muscle cells (VSMCs), and endometrial hyperplasia and luminal stenosis after vascular damage. Methods The VSMCS of rat thoracic aorta were cultured and treated with different concentrations of C-phycocyanin. DNA synthesis and proliferation state of VSMCs were determinated withtritiated thymidine (3H-TdR) incorporation, the expression of of cyclin-dependent kinase inhibitors (P21 and P27) were detected with western blot and image analysis. Rat model with restenosis of thoracic aorta after balloon damage was constructed. The rats received intragastric administration of C-phycocyanin for 14 days, and the thoracic aorta were taken out. HE staining, immunohistochemistry and image analysis computer system were applied to measure the vessel morphology, SM-α-actin, proliferating cell nuclear antigen (PCDA), and protein expression of P21 and P27. Results Active proliferation of VSMCS and low expression of P21 and P27 were examined after VSMCs were induced by fetal bovine serum (FBS). C-phycocyanin could significantly inhibit VSMCs proliferation and DNA synthesis, and meanwhile down regulate quantities of P21 and P27 protein. In rats with balloon injury, C-phycocyanin group had a outstanding smaller noeintima /media area ratio, larger internal or external elastic lamina area and luminal area; and C-phycocyanin promoted the expression of P21, P27. Conclusions C-phycocyanin could inhibit over proliferation of VSMCs and luminal narrowing after aortic balloon injury. The mechanism was probably C-PC could promote the expression of key regulatory factors (P21 and P27).