ABSTRACT
Objective To investigate the important role of angiogenin-like protein 4 (Angptl4) in pulmonary fibrosis and to provide a new therapeutic targets for pulmonary fibrosis.Methods We established the pulmonary fibrosis animal models in rat by tracheal instillation of bleomycin.Then,we detected the expression of Angptl4 through real-time polymerase chain reaction (RT-PCR) and Western Blot.Rat lung fibroblast (RLF) was transfected into Angptl4-shRNA plasmid.Then we detected the changed collagen expression in RLF cells after transfection through RT-PCR and Western blot.Results The expression of Angptl4 was up-regulated in the bleomycin-induced rat pulmonary fibrosis model.The expression of both collagen Ⅰ and collagen Ⅳ in RLF cells transfected with Angptl4-shRNA plasmids were down-regulated compared with control after TGF-β treatment.Conclusions Inhibiting the expression of Angptl4 can reduce the expression of collagen fibers in lung tissue,then delaying the progression of pulmonary fibrosis.
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.
ABSTRACT
Objective To explore the effects of MIF stimulation on collagen Ⅰ and Ⅲ synthesis in the cultured blood vessel SMC ofrats. Method The content of collagen Ⅰ and Ⅲ protein in primary culture of SMC was measured with Western-blot. Results MIF couldpromote the increasing of the collagen Ⅰ protein expression in the SMC. But there were no improvement on collagen Ⅲ. Conclusions MIFcould stimulate SMC to synthesize the collagen Ⅰ.