Influence of Lipopolysaccharide on the Proliferation and the mRNAs Expression of Procollagen TypeI,III and Collagenase of Normal Skin Fibroblasts of Hypertrophic Scar Patients

Objective To observe the influence of lipopolysaccharide(LPS) on the proliferation and the mRNAs expression of procollagen typeⅠ,Ⅲ and collagenase of normal human skin fibroblasts and its biological role in the formation of hypertrophic sacr.Methods Fibroblasts were isolated and cultured in vitro,and then exposed to different doses of LPS(0.005,0.010,0.050,0.100,0.500,1.000 μg/ml) from E.coli055:B5 respectively.Then the optical density(A) values of fibroblasts were determined with the colorirneteric thiazolylblue(MTT) assay every other day from day 1 to day 9 after LPS administration,and the cell amounts were counted under inverted phase contrast microscope on a daily basis from day 1 to day 9 after LPS administration.The expression of procollagen typeⅠ,Ⅲ and collagenase mRNAs was tested by RT-PCR.The fibroblasts from hypertrophic scar tissue obtained from the same patients in the same culture passage were used as control.Results Compared with the control group,the A value increased with the increasing concentration of LPS(0.005 ~ 0.5000 μg/ml) and LPS of 0.100 μg/ml group had the strongest effect,the difference was remarkable at day 5 to day 9(P 0.05),the A value decreased when challenged with the LPS of 1.000 μg/ml and the difference was remarkable at day 3 to day 9(P 0.05).The cell amount increased with the administration of LPS of different concentrations(0.005 ~ 0.500 μg/ml) and LPS of 0.100 μg/ml group had the strongest effect,the difference was remarkable at day 1 to day 6(P 0.05),the cell amount decreased remarkably when challenged with LPS of 1.000 μg/ml and the difference was remarkable at day 2 to day 9(P 0.05).The expression of procollagen typeⅠ,Ⅲ mRNAs of normal skin fibroblasts increased,while the expression of collagenase mRNAs of normal skin fibroblasts depressed when challenged with LPS of 0.005 ~ 0.100 μg/ml,and the influence showed a concentration dependent manner;However,when the concentration of LPS was 0.500 μg/ml,the influence of LPS on the expression of procollagen typeⅠ,Ⅲand collagenase mRNAs of normal skin fibroblasts began to decrease;when the concentration of LPS reached to 1.000 μg/ml,the expression of procollagen typeⅠ,Ⅲ mRNAs was inhibited and the expression of collagenase mRNAs began to increase.When the concentration of LPS was 0.100 μg/ml,the expression of procollagen typeⅠ,Ⅲ and collagenase mRNAs of normal human skin fibroblasts was similar to that of hypertrophic scar tissue fibroblasts.Conclusion This results support that LPS may be an important factor controlling collagen metabolism of normal skin fibroblasts and playing an important role in hypertrophic scar formation.