BACKGROUND:In recent years,studies have shown the effects of tumor necrosis factor-a(TNF-а)on fibroblasts at different organizations in a tissue-specific and dose-dependent manner.OBJECTIVE:TO investigate the biologic effects of TNF-а and its signal transduction pathway-specific kinase inhibitors on mouse embryonic fibroblasts(NIH3T3).METHODS:NIH3T3 cells were cultured in vitro,and then the cells were assigned into 3 groups.Cells in the control group were cultured in DMEM high-glucose medium with 2%serum;those in the TNF-а group were cultured in 100 μg/L TNF-аmedium;those in the TNF-а+Anti-TNFRSF 1 B group were firstly cultured in medium with 50 μg/L Anti-TNFRSF 1 B for 1 hour,and then placed in the medium with 100 μg/L TNF-а.RT-PCR and Western blot methods were used to evaluate mRNA and protein expressions of type Ⅰ collagen and matrix metalloproteinase 3(MMP3)in each group.RESULTS AND CONCLUSION:In this experiment,NlH3T3 cells cultured with a certain concentration of TNF-а,the specificity kinase signal of transduction pathway presented with phosphorylation or protein activation,and the signal pathway was activated,which promoted MMP3 activation,and significantly reduced the expression of type Ⅰ collagen.The effect of TNF-а was certainly inhibited,but not completely eliminated after adding its signal transduction pathway inhibitor Anti-TNFRSF1 B.This further proves the role of TNF-а on NIH3T3 activation.