Analysis of interleukin-17 and interleukin-18 levels in animal models of atherosclerosis

This study investigated the correlation between the levels of interleukin (IL)-17 and IL-18 and atherosclerotic plaques. A total of 60 Apo E gene (Apo E-/-) mice were fed with high-fat diet in the model group and 20 wild male C57BL/6 mice were fed with the basic diet in the control group. The serum levels of IL-17 and IL-18 were determined by enzyme-linked immunosorbent assay. Carotid artery ultrasonography was performed and divided into stable plaque, unstable plaque and non-plaque groups. The severity of plaque was estimated by semi-quantitative method and divided into grades I, II and III. The expression levels of low-density lipoprotein cholesterol, plasma total cholesterol and blood glucose level in the model group induced by high-fat diet were significantly higher than those in the control group (P<0.05). The level in the model group was significantly higher than in the control group at the 16th week (P<0.05). The expression of IL-17 and IL-18 in the model group was significantly higher than that in the control group (t=6.903, 11.02, P<0.05). The concentration of IL-17 and IL-18 in the non-plaque group was significantly lower than that in the stable plaque and unstable plaque groups (P<0.05). The concentration of IL-17 and IL-18 in the stable plaque group was significantly lower than that in the unstable plaque group (P<0.05). Based on the correlation of IL-17 and IL-18 expressions in the model group, the expression of IL-18 increased with the expression of IL-17, indicating that the expression of IL-17 was positively correlated with that of IL-18 (r=0.7195, P<0.001). In conclusion, serum IL-17 and IL-18 played an important role in the formation and development of atherosclerotic plaque, and were related to the stability and severity of plaque. The expression of IL-17 and IL-18 was positively correlated.