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目的 探讨皮质酮作用下离体SD大鼠成骨细胞SREBP(固醇调节元件结合蛋白,sterol modulates the element binding protein)1、SREBP2、HMGCR(3-羟基-3-甲基戊二酸单酰辅酶A还原酶,3-hydroxy-3-methyl malonate coenzyme A reductase)、FAS(脂肪酸合成酶,fatty acid synthase)的表达改变对细胞内脂质积聚的影响.方法 采用多次胶原酶组织消化法获得新生SD大鼠颅骨中的成骨细胞作为研究对象,观察皮质酮作用后成骨细胞内脂质积聚的特征,以及SREBP1、SREBP2、HMGCR、FAS基因及蛋白表达.结果 成骨细胞内Nile Red细胞内脂质染色可见成骨细胞内的脂质染色随皮质酮浓度的增加的逐渐增多,相同浓度的皮质酮在作用的24 h、48 h、72 h后未见明显差异;细胞内SREBP1、SREBP2、HMGCR、FAS基因表达在不同浓度皮质酮作用24 h后均明显增高,48 h、72 h后呈现下降趋势;细胞内SREBP1、SREBP2、HMGCR、FAS蛋白在1μmol/L皮质酮作用24 h后表达升高,48 h后与对照组未见明显差异,72 h后SREBP1、FAS表达降低,SREBP2表达升高,HMGCR未见明显差异.结论 超生理剂量的皮质酮能促进成骨细胞内脂质异常沉积;不同浓度皮质酮作用成骨细胞24 h后能促进细胞内SREBP1、SREBP2、HMGCR、FAS基因表达;皮质酮作用成骨细胞24 h后促进成骨细胞内SREBP1、SREBP2、HMGCR、FAS蛋白的表达.“,”Objective To investigate the effect of corticosterone on the expression of sterol modulates the element binding protein (SREBP1),SREBP2,3-hydroxy-3-methyl malonate coenzyme A reductase (HMGCR),and fatty acid synthase (FAS) in rat osteoblasts in vitro,and the effect of this change on lipid accumulation in the cells.Methods Osteoblasts from the skull of newborn SD rats with collagenase digestionmethod were research objects.The lipid accumulation characteristics and the gene and protein expressions of SREBP1,SREBP2,HMGCR,and FAS after addition of corticosterone in osteoblasts were observed.Results The Nile red lipid staining in the cells increased gradually with time after addition of corticosterone.With same concentration of corticosterone,the staining was not changed at 24 h,48 h,and 72 h.The gene and protein expressions of SREBP1,SREBP2,HMGCR,and FAS increased in 24 h,but decreased in 48 h and 72 h,after addition of different concentrations of corticosterone.When additioned with 1 μmol/L of corticosterone,the expressions of SREBP1,SREBP2,HMGCR,and FAS increased in 24 h,but were constant in 48 h comparing with control group.In 72 h,the expressions of SREBP1 and FAS decreased,the expression of SREBP2 increased,and the expression of HMGCR was constant.Conclusion Over physiological dose of corticosterone induces abnormal accumulation of lipids in osteoblasts.Different concentrations of corticosterone stimulate the gene and protein expressions of SREBP1,SREBP2,HMGCR,and FAS in osteoblasts in 24 h.