RESUMO
ObjectiveTo observe the influence of lipopolysaccharide (LPS) on collagen metabolism of normal human skin fibroblasts and its biological role in the formation of hypertrophic scar.Methods Fibroblasts were isolated and cultured in vitro,and then exposed to different doses of LPS (0.005,0.01,0.05,0.1,0.5,1.0 μg/ml) from E.coli.055:B5 respectively.The expression of proccllagen type Ⅰ,Ⅲand collagenase mRNAs was tested by RT -PCR.Fibroblasts from hypertrophic scar tissue obtained from the same patients in the same culture passage were used as control.ResultsCompared with control group,the expression of procollagen typeⅠ,Ⅲ mRNAs in normal skin fibroblasts increased (0.323 ± 0.041,0.303 ± 0.063,0.391 ± 0.071,0.344 ± 0.086,0.488 ± 0.059,0.401 ± 0.087,0.616 ± 0.107,0.434 ±0.084,0.823 ±0.092,0.542 ± 0.082),while the expression of collagenase mRNAs of normal skin fibroblasts depressed(0.598 ± 0.068,0.556 ± 0.049,0.441 ± 0.043,0.372 ± 0.083,0.260 ± 0.027 ).When LPS was set to the concentration of 0.005 μg/ml,it showed a concentration dependent manner.However,when the concentration of LPS was set to 0.5 μg/ml,the expression of procollagen type Ⅰ,Ⅲ and collagenase mRNAs of normal skin fibroblasts began to decrease (0.451 ± 0.063,0.374 ± 0.072,0.360 ± 0.062).When the concentration of LPS was set to 1.0 μg/ml,the expression of procollagen type Ⅰ,Ⅲ mRNAs (0.162 ± 0.025,0.171 ± 0.061 )were inhibited and the expression of collagenase mRNAs began to increase (0.444 ±0.114).When the concentration of LPS was set to 0.1 μg/ml,the expression of procollagen type Ⅰ,Ⅲ and collagenase mRNAs of normal skin fibroblasts(0.823 ±0.092,0.542 ±0.082,0.260 ±0.027)was similar to that of hypertrophic scar tissue fibroblasts(0.829 ±0.049,0.569 ±0.038,0.277 ±0.059).ConclusionsThis result supported that LPS may be an important factor in collagen metabolism of normal skin fibroblasts and it plays an important role in hypertrophic scar formation.
RESUMO
Objective To study the signal transduction mechanism of nicotine induced periodontal ligament fibroblasts (PDLFs) apoptosis. Methods This study used 1 μg/ml, 10μg/ml and 100μg/ml nicotine to intervene PDLFs cells for 24h separately. NF-κB, p53, I-κB and Caspase3 expression were detected. Results After Nicotine was done on PDLFs cells for 24h, the transcription of p53, and Caspase3,and the translation of Caspase 3 protein were increased, while NF-κB was decreased. At the same time, the transcription of NF-κB decreased gradually with the concentration of nicotine increased ( r = 0. 707, F =33. 705, P ＜0. 01 ), nevertheless, I-κB was reversed ( r =0. 964, F =374. 883, P ＜0. 01 ). p53 expression was increased gradually with the concentration of nicotine increased ( r =0. 957, F = 153. 377, P ＜0. 01).Both Caspase3 mRNA (r =0.935, F =318.371, P ＜0.01) and protein (r =0.677, F =8. 459, P ＜ 0. 05 )increased gradually. Conclusion Nicotine induced PDLFs apoptosis was mediated through NF-κB and p53 pathway.