Objectives To observe the effects of CD147 on matrix metalloproteinase 9 (MMP 9) expression and secretion in aortic atherosclerotic plaque in rabbits, and explore the function of CD147 knockdown to prevent atherosclerotic plaques stably from rupture.

Methods Atherosclerosis models were created by injuring carotid intimal with Liquid Nitrogen based on high fat feeding for 10 weeks and evaluated by killing 3 rabbits randomly. The remaining 27 rabbits were divided into 3 groups randomly and locally infected by injecting of normal saline, lentivirus suspension, CD147shRNA lentivirus suspension respectively. The transfection efficiency was measured by detection of enhanced green fluorescence protein. provocation test were done by Liquid Nitrogen 4 weeks after the transfection and HE staining, masson trichrome coloration, elastic fibre staining were applied 48 hours after the test to observed tissue morphology. In addition, immunohistochemistry was carried on to investigate the Expression Level of matrix metalloproteinase in the Atherosclerotic Plaque. The Expression of Free CD147/MMP-9 in Serum were tested before models, after models, transfection for 4 weeks, 48 hours after the provocation test respectively.

Results The test of GEP in carotid intima and media suggest that the modal are successful blank control group and lentivirus group have bigger lipid core with thinner fibrous cap, however, CD147 lentivirus group show a stable plaque with thicker firous cap. Immunohistochemistry show higher expression of MMP-9 in blank control group and lentivirus group. The test of Free CD147/MMP-9 in Serum suggested that CD147 lentivirus group has a lower expression than the other two groups.

Conclusions MMP-9 induced by CD147 Promote the Instability of atherosclerotic plaque and CD147 knockdown has a effect of preventing the Degradation of fibrous cap to stabilises Plaque.