The expression of CD40 and matrix metalloproteinase in canotid endarterectomy plaques and the study of plaque stability

Objective To study the expression level of CD40 and matrix metalloproteinase (MMPs) in vulnerability, stability carotid atherosclerotic plaque. Investigate the relevance of CD40 and MMPs expression and the impact on plaque stability. Methods Thirty-two cases of specimens with carotid atherosclerotic plaque were collected from carotid endarterectomy(CEA). According to preoperative carotid ultrasound, transcranial doppler (TCD) and the presence of acute ischemic stroke events, all specimens were divided into stable plaque group and vulnerable plaque group, detected the mRNA and protein expression level of CD40 and MMPs in each group using PCR and western blotting assay. Results The mRNA and protein expression level of CD40 and MMP-9 in vulnerable plaque group was significantly higher than in stable plaque group respectively(P<0.01). The MMP-2 protein expression level in vulnerable plaque group was distinctly higher than in stable plaque group(P<0.01). There were positive correlation between CD40 mRNA and MMP-2 mRNA (r=0.43, P<0.05), CD40 mRNA and MMP-9 mRNA (r=0.90, P<0.01) respectively. Conclusion CD40 is not only involved in the formation of atherosclerotic plaque, but also may influence the stability of atherosclerotic plaques by regulating the expression of MMP-2 and MMP-9. Key words: Carotid endarterectomy; Atherosclerosis; Plaque stability; Antigens, CD40; Matrix metalloproteinases