Influence of lipopolysaccharide on the cell cycle and the mRNAs expression of procollagen type Ⅰ,Ⅲ of normal human skin fibroblasts / 中国医师杂志

ABSTRACT

Objective To observe the influence of lipopolysaccharide (LPS) on the cell cycle and the mRNAs expression of procollagen type Ⅰ , Ⅲ of normal human skin fibroblasts. Methods Purified dermal fibroblasts were exposed to different doses of LPS(0. 005 ～ 1.0 μg/ml) from E. coli. Then the cell cycle of fibroblasts at logarithmic stage at day 7 after LPS administration was assayed with flow cytometry.The expression of procollagen type Ⅰ , Ⅲ and collagenase mRNAs was tested by RT-PCR. Results The percentage of S phase cells in cell cycle of normal human skin fibroblasts increased when LPS concentrations were changed from 0. 005 to 0. 1 μg/ml, and the increase showed a concentration dependent manner. However, when the concentration of LPS was 0. 5 μg/ml, the percentage of S phase cells began to decrease, but still higher than normal control. When LPS concentration reached 1.0 μg/ml, the percentage of S phase cells were lower than normal control. The expression of procollagen type Ⅰ , Ⅲ mRNAs of normal skin fibroblasts increased when LPS was challenged to the concentration of 0. 005 μg/ml, and the influence showed a concentration dependent manner. However, when the concentration of LPS was 0. 5 μg/ml, the influence of LPS on the expression of procollagen type Ⅰ , Ⅲ of normal skin fibroblasts began to decrease.When the concentration of LPS reached 1.0 μg/ml, the expression of procollagen type Ⅰ , Ⅲ mRNAs were inhibited. Conclusions LPS promoted the proliferation and collagen synthesis of normal human skin fibroblasts within a certain range of low doses, while high doses of LPS might inhibit the proliferation and collagen synthesis of normal human skin fibroblasts.