甘草酸减少鼠肝纤维化Ito细胞IⅢ型前胶原mRNA表达和胶原沉积

Effect of Glycyrrhetinic Acid on Reducing Expression of Procollagen type

目的:观察甘草酸对鼠肝纤维化时Ito。细胞增殖和IⅢ型前胶原mRNA表达和肝脏胶原沉积的影响。方法:以CCl_4复制肝纤维化模型,动物分组为止常对照组,模型对照组及甘草酸治疗组三个大组,各组又包括早(2周),中(6周)。晚(9周)期组,分别于用药后第2、6、9周处死动物,分离提取肝Ito细胞,培养两周后提取总RNA,以DIG High-Prlmer去标记IⅢ型前胶析和间质胶原酶cDNA探针,Northern杂交分析IⅢ型前胶原和间质胶原酶mRNA表达.鼠肝IⅢ型胶原沉积用Dot blot测定,用~3H-TDR^3H-脯氨酸观察甘草酸对培养的Ito细胞增殖和胶原合成的影响 结果,甘草酸对Ito细胞H-TDR和H-脯氨酸的掺入在4h、24h、48h与空白对照比呈明显抑制作用(P<0.05),其抑制率分别为15％、21％、31％,在甘草酸浓度≤0.125μg/ml时,对Ito细胞~3H-TDR掺入抑制不明显,而≥0.25μg/ml时呈现明显抑制作用(P<0.05),对H脯氨酸掺入,在甘草酸浓度≥0.125μg/ml时,则出现明显抑制作用(P<0.05),且随浓度增加而抑制作用加强。在鼠肝纤维化早、中、晚各期,模型对照组Ito细胞IⅢ型前胶原mRNA表达均高于正常对照组(P<0.05),甘草酸组各期Ito细胞IⅢ型前胶原mRNA表达与模型对照组比均显著降低(P<0.05).Ito细胞间质胶原酶mRNA表达.在早、中期模型对照组均高于正常对照组(P<0.

Background Aims: To observe the effect of glycyrrhetinic acid on proliferation, expression of procollagen type I Ⅲ procollagen mRNA and desposition of collagen type I Ⅲ in fibrotic liver of rat. Methods: The liver fibrosis model of rat was induced by CCl4. The rats was classified as normal control group, model control group and glycyrrhetinic acid treated group. Each group contained early, middle, late stage subgroup. After using drugs for 2, 6 and 9 weeks, the rats were killed respectivly. The Ito cells were isolated from liver and cultured in DMEM medium. The effect of glycyrrhetinic acid on proliferation and collagen synthesis of Ito cells were determined with H-TDR. H-proline incoperating test After culturing two weeks, total RNA of Ito cells were etracted. The cDNA of procollagen typeI Ⅲ and interstitial collagenase were labeled using Dig High Primer technique. The level of procollagen type I Ⅲ and interstitial collagenase mRNA were measured by Northern blot. Desposition of collagen type I Ⅲ in fibrotic liver was evaluated with Dot blot. Results: At 4h, 24h, 48h, glycyrrhetinic acid inhibited the intake of H-TDR. H-prolme by Ito cells significantly. The inhibition rate was 15% , 21%,31%, respectively. When the concentration of glycyrrhetinic acid ≥0.125μg/ml, the intake of H-prohne by Ito cells was inhibited obviously. Only the concentration of glycyrrhetinic acid≥0.25μg ml. it showed inhibition to H-TDR The level of procollagen type I Ⅲ mRNA in glycyrrhetinic acid treated group was significantly lower than model controle group in all stage of fibrosis. At 2. 6 week groups, the desposition of collagen type I Ⅲ in glycyrrhetinic acid treated group was decreased significantly than model control group. No difference was found in 9 week groups. There was no difference in expression of collagenase mRNA between glycyrrhetinic acid treated group and model control group. Conclusions: Glycyrrhetimc acid inhibited the proliferation and collagen synthesis of Ito cells. Downregulated expression of procollagen type I Ⅲ mRNA and reduced desposition of collagen type I Ⅲ in fibrosis liver There was no effect of collagenase