Regulation Of Vitamin C To The MICAM-1 On Cells Induced By The Lipid Associated Membrane Protein Of Mycoplasma Pneumoniae

Objective To extract the lipid associated membrane protein of Mycoplasma pneumoniae (Mp-LAMP) with Triton X-114, investigate the effect of Mp-LAMP on the expression of mICAM-1 on the ECV304 cells,study the target component of Mp-LAMP; to observe the effect of antioxidant vitamin C on the levels of mICAM-1 on A549 cells and ECV304cells induced by Mp-LAMP and explore the inhibition effect of vitamin C on inflammation caused by the infection of Mycoplasma pneumoniae.Methods: The research was divided into two parts. Part l:to extract Mp-LAMP and stimulate human umbilical vein endothelial cell line ECV304 cell with Mp-LAMP, flow cytometer assay was adopted to analyze the expression of mICAM-1 on the ECV304 cells respectively induced by Mp-LAMPs of eight different densities(0μg /ml,5 μg /ml,10 μg/ ml,15μg /ml,20μg/ml,25μg /ml,30μg/ ml,40μg/ ml)and five different times(0h, 4h, 8h, 16h, 24h, 32h). pretreated the Mp-LAMPs with proteinase K(0.2 μg/ml),lipoprotein lipase(0.2μg/ml) including their corresponding controls, then observed the effect on the expression level of mICAM-1 on the ECV304 cells; Part 2: ECV 304 cells and human lung carcinoma cell line A549 cells were treated with five different density of vitamin C (0 umol/L,25umol/L,50umol/L,100umol/L,200umol/L) together with 25 μg/ml Mp-LAMP, then analyze the expression of mICAM-1 on ECV 304 cells and A549 cells.Results: The expression level of mICAM-1 on the ECV304 cells was enhanced obviously when incubated with Mp-LAMP as compared with that of normal cells , the extent of increase depended on the density of Mp-LAMP(P<0.01),but no higher increase as the stimulatory density is higher than 25 μg/ml.The expression level of mICAM-1 increased gradually and reached its peak between the time of 16—24 hours then decreased slowly when incubated with Mp-LAMP of 25 μg/ml;The enzyme-digestion test showed that the lipid moiety of Mp-LAMP was the targetcomponent that had the inductive ability; Vitamin C had the significant inhibitory effect on the upregulation of expression of mICAM-1 of ECV304 cells stimulated by Mp-LAMP(P<0.05),the downregulation of their expression levels was dependent on the density of Vitamin C.but Vitamin C had no such effect on A549 cells.Conclusion: The lipid moiety of Mp-LAMP has the function to induce the upregulation of expression level of mICAM-1 on ECV cells and influences the intensity of inflammation caused by the infection of Mycoplasma pneumoniae to a great extent; Vitmain C can downregulation the expression of mICAM-1 on the ECV cells stimulated by Mp-LAMP, but no such effect on A549 cell. Vitamin C has an inhibition effect on the tensity of inflammation triggered by Mycoplasma pneumoniae on vessel.