Effects of serous amyloid P component on atherosclerosis in ApoE-/- mice / 解放军医学杂志

ABSTRACT

Objective To investigate the effect of serous amyloid P (SAP) component on serum paraoxonase 1 (PON1) activity, serum monocyte chemotactic protein 1 (MCP-1) expression and atherosclerosis progression in ApoE-/- mice, and explore the possible mechanisms thereof. Methods Six male C57/BL6 mice were fed with chow diet as normal control group. Twelve male ApoE-/- mice fed with western diet for 12 weeks were used to establish animal models of atherosclerosis, and then randomly divided into two groups (6 each) SAP and PBS group. Mice in SAP group were treated (i.p.) with SAP (6mg/g) every other day from day 0 to day 14. Mice in normal and PBS group were treated (i.p.) with PBS (same volume as SAP group) every other day from day 0 to day 14. The blood specimen and aorta vascular tissues were collected at the 16th week after the first immunization. Serum lipids and PON1 activity were assessed. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of serum SAP and MCP-1. Hematoxylin-eosin (HE) staining was used to observe the formation of atherosclerotic plaque. Oil red O staining was performed to observe the lipid accumulation, and immunohistochemical staining was performed to detect the SAP expression in the atherosclerotic plaque. Results Compared with the normal group, the serum PON1 activity reduced significantly while MCP-1 expression increased (P<0.01), and a large number of plaques formed in the blood vessels of mice in SAP and PBS group. Compered with PBS group, SAP treatment markedly improved the PON1 activity (P=0.046) and down-regulated MCP-1 expression (P=0.032). Furthermore, SAP treatment significantly reduced atherosclerotic plaque area (P=0.001) and oil red O positive area (P=0.03). Conclusion SAP could mitigate atherosclerotic lesion through improving the property of PON1 and down-regulating the level of MCP-1.