目的：比较维生素D(VD)作用下的老龄大鼠和正常饮食组老龄大鼠肝脏细胞发生自噬的程度，以探索VD与自噬的关系，同时比较两组大鼠肾脏组织中自噬相关因子PTEN的蛋白表达。方法将40只24个月老龄雄性SD大鼠随机分为实验组和对照组，每组各20只，实验组大鼠每天经灌胃给予最佳剂量的VD(预实验得到最佳浓度3.704µg/kg)，对照组正常饮食。6个月后，活体状态下取1 mm3肝脏组织4℃保存，100 g肝组织-70℃冻存，用透射电镜观察各组肝脏细胞自噬泡的数量；用免疫组化检测PTEN蛋白表达。结果电镜下实验组细胞均出现典型自噬细胞形态学改变。与正常组相比，VD作用下的大鼠肝脏细胞自噬泡占细胞质总面积的比值均明显提高(P<0.01)，免疫组化方法示实验组细胞PTEN表达较正常组显著升高(P<0.01)。结论透射电镜检测细胞自噬方法证实VD可增强细胞发生自体吞噬，同时细胞的PTEN蛋白表达量也相应提高，推测VD引起自噬过程中可能与PTEN有关。%ObjectiveTo probe into the relationship between vitamin D(VD)and autophagy by comparing two groups which are VD group and normal diet group of older rats liver’s autophagy level, meanwhile compare the expressions of the autophagy-related factor PTEN of kidney between the two groups.Methods24-month-aged rats were randomly grouped into two groups -control group(normal dieting), experimental group(the appropriate VD by gavaging)with 20 rats in each group. After six months, get liver tissues by autopsy, then make 1 mm3 liver stored at 4℃ meanwhile 100 g liver tissues at-70℃. To detect the amount of autophagic vacuoles in liver cell by TEM(transmission electron microscope); using immunohistochemical staining method to detect the expression of PTEN.ResultsTypical morphological changes of autophagy can be seen in cell. Compared with control group, the ratio of the amount of autophagic vacuoles to that of total cytoplasm in experimental group increased signiifcantly(P<0.01), PTEN in experimental group increased signiifcantly(P<0.01).ConclusionThe detection methods prove that VD can enhance the probability of autophagy in cells, Meanwhile the result that PTEN expression varied with the extension of autophagy, indicate that the autophagy induced by VD maybe related to PTEN.
展开▼
