| Background:MMPs played important roles in the occurrence and development of atherosclerosis. They not only involved in the infiltration of inflammatory cells into local plaques and the migration of vascular smooth muscle cells, but also prompt the fracture of plaques by degrading extracellular matrix. The degradation was the main factor that caused the instability even the fracture of plaques and therefore acutes coronary events.Studies have demonstrated that atherosclerosis results from the joint operation of multiple factors together, in which inflammatory cells act as the main ones, T lymphocytes and monocytes being the most important. In the inflammation process, monocytes are induced to migrate to vascular endothelial, and differentiate into macrophages which can swallow lipids forming lipid cores, and meanwhile secrete quantities of MMP-9that result in the instability of plaques in atherosclerosis. Extracellular matrix metalloproteinase inducer (EMMPRIN), also named CD147molecule, is separated from lung cancer cell lines LX-1first. As a member of the IgSF superfamily, it is a highly-glycosylated single transmembrane protein. CD147are highly expressed on tumor cells and fibroblasts in breast cancers, skin cancers and so on. It can induce fibroblasts to express masses of MMPs through paracrine and autocrine. But about whether CD147that T lymphocytes express is capable of inducing chemotactic activities on monocytes or the secretion of MMPs, no literatures at home or abroad have drawn any conclusion.Objective:we decide to imitate cell growth microenvironment in vivo, establish a co-cultivation system of T lymphocytes and monocytes. Thus, we can observe the interactions between these two kinds of cells, and watch influences on the chemotaxis for monocytes and secretion of MMPs by regulating the expression of CD147from human T lymphocytes, to probe the possible mechanism of atherosclerosis and probable prevention and cure target.Methods:First, screen drugs(PHA, PMA, Ara-C) that could activate human T lymphocytes:check the level of CD147mRNA,CD147proteins,and memberance proteins expression on Jurkat cells with the application of techniques such as RT-PCR, Westen Bloting, Flow Cytometry and so on, and screen out drugs that could raise CD147secretion effectively. And then, stimulate Jurkat cells with these drugs, co-cultivate them with THP-1cells, and do observations through experiments. Observe the effects of up-regulated CD147on the chemotaxis for monocytes through chemotactic experiments. Stimulate T lymphocytes and monocytes for24hours with CyPA and CsA and then watch their influences on the secretion of MMP-9in supernate through ELISA experiments.Result:After stimulating Jurkat cells with low concentration of Ara-C for48hours, the expression of CD147mRNA and proteins in experimental group is significantly higher than that in control group, among which CD147memberance proteins are distinctly raised, with the highest raise rate of MFI up to76%. And there are statistical differences between the experimental group and the control group(p<0.05). After co-cultivation of normal Jurkat cells and THP-1cells for24hours, only a small amout of MMP-9has been found in supernate, while MMP-9obviously increased after up-regulating the expression of CD147from Jurkat cells with10ng/ml Ara-C, at the same time the chemotactic activity on monocytes are enhanced(p<0.05). CyPA promotes MMP-9secretion while CsA inhibits it in the co-culture system (p<0.05).Conclusion:1. Ara-C can up-regulate the expression of CD147mRNA and proteins in T lymphocytes effectively.2. In the co-culture system of Jurkat cells and THP-1cells, it can promote the chemotactic activity on monocytes and the secretion of MMP-9to up-regulate the expression of CD147from Jurkat cells.3. After dealing the coculture system of Jurkat cells and THP-1cells with CyPA and CsA respectively, they can promte or inhibit the secretion of MMP-9in supernate respectively. |
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