The Effection of All-trans Retinoic Acid(ATRA) on the Expression of MCP-1 and TLR-4 in Atherosclerotic Lesions of Rabbits

Objective: To investigate the efficacy of ATRA on the tunica intima proliferation,the expression of MCP-1(monocyte chemotatic protein-1),TLR-4(Toll-like receptor4) in the injury and repair lesion located at the intima of the rabbit carotid artery,in order to study the possible mechanism of anti-inflammation of ATRA.Methods: New Zealand male rabbits were randomly divided into 9 groups(n=6) control group(ABC) experimental group(ABC),sham operated group(ABC).Except the sham operated group,the other two groups had been given high fat diet for two weeks.And the rabbits of control and experimental group were given air drying operation to injure the carotid artery intima.In the sham operated group,carotid arteries were dissected and exposed without injuring the intima.The rabbits of experimental group were not given ATRA intragastric administration three days before the operation until the execution.The rabbits of group A were put to death 7 days after the operation,group B 14 days,and group C 28 days.Then the specimens of carotid arteries were took the and the morphology of atherosclerotic lesions were detected and measured At last,the expression levels of MCP-1 and TLR-4 were detected by the method of immunohistochemisty.Results: ①In the control group,the intima started to proliferate 7 days after the air seasoning operation.After 14 /28 days the intima proliferated obviously with lumen stenosis,atheromatous plaque on the vessel wall and much expression of MCP-1 and TLR-4;②In the experimental group,the intima proliferated much less severely.14 and 28 days after the operation,the area of the proliferating intima was smaller(P0.05),the opaque was thinner(P0.05),and the positive expression of MCP-1 and TLR-4 was smaller(P0.05) than those of the control group;③ In the sham operated group,the intima didn't proliferate,MCP-1 and TLR-4 had little expression.Conclusions: ATRA alleviated the intima proliferation and lumen stenosis after the carotid artery intima injured by inhibiting the expression of MCP,TLR-4 and the other inflammatory factors probably.