The Effects Of Radionuclide ～(90)Sr On Proliferation And Synthesis Of The Cultured Fibroblasts From Hypertrophic Scar

Objective: To study the effects of ⁹⁰Sr on cell cycle,apoptosis and synthesis of the fibroblasts from hypertrophic scar tissue for investigate the mechanism of hypertrophic scars with treatment of ⁹⁰Sr. Method: The cultured fibroblasts were divided into 4 groups: the 1500rad group, the 1000rad group, the 500rad group and the 0rad group(control group).The cell cycle and apoptosis were examed by flow cytometry at 0,24,48,72 hours after irradiated by ⁹⁰Sr.While the cell growth curve was drawn by MTT assay. Collagenâ… , collagenâ…¢,MMP-1(matrix metalloproteinases),TGF-β1 (transforming growth factorβ1)productions in culture medium was detected by enzyme-linked immunosorbent assay (ELISA). Result:â‘ Apoptosis: the apoptotic rates of 1500rad group and 1000rad group were increased quickly and reached 61.61±1.56%,64.02±3.21% at 72h.However the apoptotic rate of 500rad were decreased quickly (reached 16.53±0.91%)at 72h.â‘¡Cell cycle: after fibroblasts were irradiated by 1500rad and 1000rad of ⁹⁰Sr, the percentage of S phase cells increased significantly at 72h(P＜0.05).â‘¢MTT: the OD of the 1500rad group and the 1000rad group were significantly lower than the control at 24h,48h,72h.The fibroblast proliferation were inhibited after irradiated by 1500rad and 1000rad.â‘£Collagenâ… : the collagenâ… productions of 1500rad group,1000rad group and 500rad group were significantly lower than the control at 24h,48h,72h(P＜0.05).⁹⁰Sr inhibited the content of collagenâ… in a dose-dependent manner.⑤Collagenâ…¢: the collagenâ…¢productions of 1500rad group,1000rad group and 500rad group were significantly higher than the control at 24h,48h,72h(P＜0.05). ⁹⁰Sr increased the content of collagenâ… in a dose-dependent manner.â‘¥MMP-1: the MMP-1 productions of 1500rad group,1000rad group and 500rad group were significantly higher than the control at 48h(P＜0.05). ⁹⁰Sr increased the content of MMP-1 in a dose-dependent manner. The content of 500rad group were very close to that of the control at 72h(P＞0.05).⑦TGF-β1: the TGF-β1 productions of 1500rad group,1000rad group and 500rad group were significantly lower than the control at 24h,48h,72h(P＜0.05). ⁹⁰Sr inhibited the content of TGF-β1 in a dose-dependent manner. Conclusion: The effect of ⁹⁰sr were achieved by inhibiting proliferation of fibroblasts, promoting apoptosis of fibroblast, changing ratio of collagenâ… /â…¢, increasing contents of MMP-1 and decreasing contents of TGF-β1.