维生素D对细胞自噬及相关因子P62/SQSTM1、VDR表达的影响

Effects of active vitamin D on autophagy-related factor P62/SQSTM1 and VDR

目的探讨活性维生素D在老龄大鼠体内诱导细胞发生自噬及相关因子P62/SQSTM1,VDR表达的变化。方法 21只18月龄雄性SD大鼠随机分为三组:对照组;低剂量组[VD,0.025μg/(kg·d)];高剂量组[VD,0.1μg/(kg·d)]。对照组给予正常饮食,定时加水;其余两组也给予正常饮食,并分别用相应剂量的VD每日给大鼠灌胃。干预180 d后,处死大鼠,电镜观察肝脏细胞自噬程度,Western blot检测P62/SQSTM1、VDR蛋白表达。结果 1.电镜下可见对照组自噬泡占胞浆面积比小于其余两组(P<0.05),低剂量组和高剂量组自噬泡占胞浆面积比无明显差异(P>0.05);2.Western blot检测分析,对照组P62表达量高于其余两组(P<0.05),低和高两剂量组之间无明显差异(P>0.05);3.Western blot检测分析,高剂量组VDR蛋白表达稍高于对照组和低剂量组,但差异无统计学意义(P>0.05),同时对照、低和高剂量组三组间VDR表达量也无明显差异(P>0.05)。结论 1.通过电镜观察,说明在老龄大鼠肝脏内VD可以诱导细胞自噬现象发生;2.使用VD干预老龄大鼠,可使P62蛋白量下降;3.VD诱导自噬和VD的受体VDR之间的关系尚不明确,需进一步研究。

Objective To investigate cells autophagy and the changes of autophagy related factors P62/SQSTM1, VDR induced by active vitamin D in aging rats. Methods The 21 18-month aged male SD rats were randomly divided into three groups： control group; low dose group [VD, 0.025 μg/（kg.d）]; high dose group [VD, 0.1 μg/（kg-d）]. The control group was given a normal diet. The remaining groLtps were given normal daily diet also, and were lavaged daily with a dose of 0.025μg/kg, 0.1μg/kg of VD respectively： After 180 days, the rat were executed, observed the liver cell au- tophagy degree using electron microscope, at the same time, detection of P62/SQSTM1, VDR （VD receptor） protein ex- pression using western blot. Results 1. The proportion of autophagosome to the area of cytoplasm was less than the oth- er groups in control group （P 〈 0.05）. On the contrary, there was no significant differences between low dose group and high dose group（P 〉 0.05）. 2.P62 protein level had been increased（P 〈 0.05） compared to the rest of the two groups in control group. P62 protein level had no significant differences between low dose group and high dose group （P 〉 0.05）. 3. VDR protein level was slightly higher than the other groups in high dose group, but without statistical significance（P 〉 0.05）, and there were no significant differences between control group, low dose group and high dose group （P 〉 0.05）. Conclusion 1. Cell autophagy can be induced by VD in aging rat＇s liver. 2. The amount of P62 has been de- creased by VD intervention in ageing rats. 3. The relationship between VDR and the mechanism of autophagy induced bv VD is still not clear, and has yet to be further research.