Objective: To observe the expression of PECAM-1 and E-selectin in the vulnerable plagues and their relationships to myocardial Leu125Val polymorphism of PECAM-1 and Ser128Arg polymorphism of E-selectin in autopsied samples of patients with acute coronary syndrome (ACS).
Methods: We detected the expressions of PECAM-1 and E-selectin in the vulnerable plaques by immunohistochemistry on 50 autopsy samples of patients with ACS, 30 autopsy samples from non-cardiac disease patients served as control. Genetic Leu125Val polymorphism of PECAM-1 was detected by PCR-SSCP in myocardial paraffin blocks of 37 ACS cases and 43 control cases, and Ser128Arg polymorphism of E-selectin was detected by PCR-RFLP in myocardial paraffin blocks of 39 ACS cases and 43 control cases, respectively.
Results: Immunohistochemical features: (1) the incidence of positive expression in the intima of coronary artery of PECAM-1 [76.0% (38/50) vs. 26.7% (8/30)] and E-selectin [26.0% (13/50) vs. 0] was significantly higher in ACS group than in control group (all P < 0.01). (2) Expressions of PECAM-1 [58.0% (29/50) vs. 28.0% (14/50)] and E-selectin [22.0% (11/50) vs.12.0% (6/50)] were significantly higher at neovascular endothelial cells in plaques than expressions at coronary arterial endothelial cells in ACS group (all P < 0.01). (3) In 41 plaques with inflammatory infiltration, the expression rates of PECAM-1 and E-selectin in inflammatory cell density of < 10, 10 - 30 and > 30/HPF were 33.3%, 68.2%, 92.3% and 16.7%, 31.8% and 23.1%, respectively. Genotype detection results: There is significant difference in frequencies of allele in Leu125Val polymorphism (P < 0.05), but the genotype distributional frequencies were similar (P > 0.05) between ACS group and control group. There are significant differences in frequencies of allele and genotype in Ser128Arg of E-selectin polymorphism between ACS group and control group (all P < 0.05).
Conclusions: The immunohistochemical expressions of PECAM-1 and E-selectin were significantly increased at intima in vulnerable plaques of ACS group, especially in neovascular endothelial cells, and positively correlated with inflammatory cell density, suggesting that PECAM-1 and E-selectin might play an important role in inflammatory reaction and development of vulnerable plaque. E-selectin Ser128Arg polymorphism is associated with ACS, and it might be a risk factor for ACS.