Effects Of DMOG On Proliferation,apoptosis And Collagen Synthesis Of Human Keloid Fibroblasts

Objective :To investigate the effects of DMOG(Dimethyloxalyl)on the proliferation,apoptosis and collagen synthesis of cultured human keloid fibroblasts in vitro under the conditions of hypoxia and hypoxia,and explore the mechanism of its action.Methods Using different concentrations of DMOG role on cultured keloid fibroblasts,MTT assay were used to detect the difference of their proliferation levels and the median inhibitory concentration(IC50)and the best intervention time;Keloid fibroblasts were divided into control group and DMOG group(IC50=800μmol/L DMOG),hypoxia group and hypoxia + DMOG group(hypoxia+800μmol/L DMOG),after36 h,RT-PCR,Western blotting and MTT assay were used to detect two cells of HIF-1α,COL1A1,COL3A1,p53,Bcl-2,Bax m RNA and protein expression level;MTT was used to detect the cell proliferation,the apoptosis and cell cycle were detected by flow cytometry.Collagen synthesis was measured by hydroxyproline colorimetric method.And the statistical software was used for data processing and statistical analysis.Results With the increase of the concentration of DMOG(200μmol/L,400μmol/L,800μmol/L,1600μmol/L),DMOG inhibited the proliferation of fibroblasts in the keloid fibroblasts with dependence of concentration and time.The median inhibition concentration(IC50)and the optimal intervention time were 800 mol/L and 36h;The expression of HIF-1α protein and m RNA in hypoxia group,DMOG group and hypoxia+DMOG group were higher than those in control group,(P<0.01).Compared with control group,the p53 and Bax protein in hypoxia group,DMOG group and hypoxia+DMOG group were significantly higher(P<0.01),and the protein expression of Bcl-2 was significantly lower.(P<0.01);Compared with the control group,the cell proliferation in other three groups were inhibited,the absorbance of cells in DMOG group and hypoxia group +DMOG was significantly lower than that in control group after 36h(0.54±0.01、0.29±0.02vs1.01±0.02),(P < 0.01).Compared with the control group,the apoptosis rate of DMOG group and +DMOG group were significantly higher(P < 0.01),the apoptosis rate of the hypoxia group was also slightly elevated(P<0.01).The proportion of G0/G1 phase cells in hypoxia group,DMOG group and hypoxia +DMOG group increased than that in control group(P<0.01),and the proportion of S phase cells and G2/M phase cells decreased(P<0.01);Compared with the control group,the m RNA and protein levels of hydroxyproline,COL1A1,COL3A1 were increased in hypoxia group(P< 0.05),but they all significantly decreased in the DMOG group and hypoxia +DMOG group;(P < 0.05)Conclusions DMOG can inhibit the proliferation of keloid fibroblasts in vitro with dependence of concentration and time.Under certain conditions,increase the level of HIF-1α,lead to the early stage of DNA synthesis(G0/G1)block,promote apoptosis,and significantly inhibit collagen synthesis.