Effect Of MCP-1 And MIP-1α On The Formation And Development Of Atherosclerosis In Type 2 Diabetes Mellitus

Atherosclerosis( AS) is a kind of chronic inflammatory disease. The infiltration of inflammatory cells in tunica intima of artery proliferation of smooth muscle cells increase of extracellular matrix and thrombosis all exist during the whole process of atherosclerosis. One of the early visible changes is the increased adherence of monocytes to arterial endothelium. Monocytes can be attracted by many chemokines during the process and the role of monocyte che-moattractant protein-1 ( MCP-1) among them is confirmed by many investigators. It was reported .that the atherosclerotic lesions of mice knocked out the MCP-1 gene and the low density lipoprotein receptor gene at the same time were relieved more obviously than that of mice only knocked out the low density lipoprotein receptor gene after they were fed high cholesterol diet,but the atherosclerotic lesions didn't disappear completely. The infiltration of macrophages still existed in aortic wall. The results showed that other chemokines except MCP-1 also took part in the process that monocytes migrated to sub-endothelial space. Macro-phage inflammatory protein-1 a ( MIP-1 a ) and MCP-1 belong to CC chemokines and MIP-1 a also takes part in the recruitment of monocytes and the formation of foam cells . Moreover, MIP-1 a exists in atherosclerotic plaques. So we can see that MIP-1 a plays an important role in the occurrence of atherosclerosis.There is no significant difference in histology of large vessels between diabetics and general patients with atherosclerosis. But the occurrence of atherosclerosis in diabetics is earlier than that in general patients with atherosclerosis. The progress of atherosclerosis in diabetics is also quicker and the prognosis of atherosclerosis in diabetics is worse than general patients with atherosclerosis, which is the important reason that causes type 2 diabetics death and mutilation. It is reported that plasm levels of MCP-1 and MIP-1 a in diabetics are high, but there is no report about the expression and distribution of MCP-1 and MIP-1atin athero-sclerotic tunica intima of artery from diabetics. In this investigation we used im-munohistochemistry methods to detect the expression and distribution of MCP-1 and MlP-la in atherosclerotic tunica intima of artery from type 2 diabetics and non-diabetics and tried to find out the effect of MCP-1 and MlP-la on the formation and development of atherosclerosis in type 2 diabetics.Endothelial cells are first activated during the process of atherosclerosis. After endothelial cells are stimulated by many factors, they can cause and amplify the inflammatory reaction of arterial wall by excreting inflammatory medium or regulating the adhesiveness of leucocytes on the surface of endothelial cells. Hy-perglycemia and advanced glycation end products ( AGEs) are the initial and major metabolic abnormalities in diabetics and the effects of these two metabolic abnormalities on the expression of MlP-la in endothelial cells are still unclear at present. So we studied the effects of glucose and AGEs on the expression of MIP-lamRNA and protein in endothelial cells in order to provide the theoretic basis for further investigating lesions of large vessels in diabetics.Methods1. Disposal of artery specimen:Fresh specimen obtained during the operation were embedded within 30min,then placed in liquid nitrogon and frozen quickly. These specimen were packed with Aluminium foil after taken out,then preserved in -801 refrigerator with article number. 6m frozen sections were made by using cryostat microtome before experiments were carried out. The sections were fixated in 4% paraform-aldehyde for 20min, then washed by PBS.2. Cell culture and synchronization of cell cycle( 1) Human umbilical vein endothelial cell line ( ECV304) was purchased from Shanghai Cell Institute. ECV304 were cultured with RMPI1640 culture media containing 10% (vol/vol) inactivated newborn bovine serum at 37 and 5% CO2. Culture media were changed every two days and 0.25% trypsin was used to digest and transfe...