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Objective To observe the expression of interferon induced protein (IP)-10 and the role of nuclear factor-kappaB (NF-κB) signaling pathway in rat peritoneal mesothelial cells (RPMCs) under the action of lipopolysaccharide (LPS).Methods RPMCs were harvested from Sprague-Dawley rat peritoneal cavity and cultured under defined in vitro conditions.The cells were exposed respectively to different concentrations of LPS (0,10,100,1 000,10 000 ng/ml) for 3 h or treated with LPS (100 ng/ml)for different time points (0,1,3,6,12,24,48 h).For observing the effect of LPS on the expression of p-p65 and p65,the RPMCs were treated with LPS (100 ng/ml) for different time points (0,15,30,60,120 min).For observing the effect of BAY11-7085 on the expression of IP-10 mRNA,the RPMCs were treated by LPS or pretreated with BAY11-7085 (5 μ mol/L) for2 h,then treated with LPS for another 3 h,respectively.Expression of IP-10 mRNA was examined by reverse transcription-polymerase chain reaction (RT-PCR).Expression of NF-κB and p-NF-κB protein was detected by Western blot.The secretion of IP-10 was determined by enzyme-linked immunosorbent assay (ELISA).Results Compared with the control group,stimulation of RPMCs with 10 ng/ml LPS resulted in a significant increase in the expression of IP-10 mRNA (P ＜0.05).1 000 ng/ml LPS has the strongest effect on IP-10 expression compared with that of 10 ng/ml and 100 ng/ml LPS.Treatment with 100 ng/ml LPS resuhed in time-dependent increase in the gene level of IP-10,with the peak at 3 h.However,after that time point,the gene level of them was gradually attenuated.Following treatment with LPS (100 ng/ml),the level of p-NF-κB began to increase at 15 min,gradually reached the peak at 1 hour,and then decreased.But the level of which at 2 h is still significant higher than that of medium control.5 μmol/L BAY11-7085 significantly decreased the up-regulation of IP-10 induced by LPS.Conclusions LPS enhanced the expression of IP-10 on RPMCs in a concentration-dependent and a time-dependent manner.LPS induced expression of IP-10 depended on the NF-κB signal transduction pathway.
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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.
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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.
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ObjectiveTo explore the effect and mechanism of Toll-like receptor 4(TLR4) ligand LPS-mediated inhibition hepatitis B virus (HBV) replication in Bewo cells.MethodsFirst of all,2 μg 1.3-fold HBV recombinant vector pcDNA3.1 ( + )-HBV1.3 were transfected into Bewo cells,after 12 h,the cells were treated with LPS for 3 d.To observe the kinetics of IFN-β and TNF-α expression in Bewo cells,the Bewo cells were exposed to TLR4 ligand LPS.And the effect of pyrrolidine dithiocarbamate ( PDTC),an inhibitor of NF-κB,on LPS-induced cytokines was also observed.The HBsAg,HBeAg and HBV DNA level in the culture supernatant were detected by Microparticle Enzyme Immunoassay (MEIA) and fluorescence quantitative PCR,respectively,and the expression of IFN-β,TNF-α,TRIF and MyD88 was detected by ELISA and RT-PCR,respectively.ResultsCompared with control group,LPS could significantly suppress HBV replication in Bewo cells ( P ＜0.01 ),and it could induce the production of TNFα in Bewo cells ( P ＜ 0.05 ),in time-and dose-dependent manners.PDTC strongly inhibited LPS and induced TNF-α production,but had no much effect on IFN-β in Bewo cells ( P ＜ 0.001 ).Compared with control group,the mRNA levels of MyD88 were significantly induced by LPS in the Bewo cells transfected with this recombinant vector( P ＜ 0.001 ).ConclusionsTLR4 ligand LPS could significantly suppress HBV replication by inducing TNF-α production in Bewo cells mainly via the MyD88/ NF-κB signal pathway.