纳米二氧化钛对小鼠卵巢组织中甾醇O-酰基转移酶1与类固醇合成急性调节蛋白表达的影响

Effects of nano-titanium oxide on expression of SOAT1 and STAR proteins in ovarian tissue of mice

目的研究纳米二氧化钛染毒对小鼠卵巢组织中甾醇O-酰基转移酶1(SOAT1)与类固醇合成急性调节蛋白(STAR)表达的影响。方法将48只40日龄清洁级ICR雌性小鼠随机分为4组,分别为对照(0.5%羧甲基纤维素)组和25、50、100 mg/kg纳米二氧化钛染毒组,每组12只。通过灌胃方式进行染毒,染毒容积为10 ml/kg,每天1次,连续染毒60 d。采用基因芯片检测100 mg/kg纳米二氧化钛染毒60 d小鼠卵巢组织中类固醇代谢相关基因表达的影响。采用实时定量PCR法检测100 mg/kg纳米二氧化钛染毒60 d后卵巢组织SOAT1与STAR基因表达的水平。使用ELISA法检测各剂量纳米二氧化钛染毒15、30、60 d后卵巢组织SOAT1与STAR蛋白水平。结果与对照组比较,以差异值≥13分或≤-13分为筛选标准,在100 mg/kg纳米二氧化钛染毒60 d小鼠卵巢中已知功能为类固醇代谢的差异表达基因中,Soat1、Star、Cyp17a1和Cyp11a1表达上调,Cyp2b1、Akr1c19和Cyp2a5表达下调。与对照组比较,100 mg/kg纳米二氧化钛染毒60 d小鼠卵巢中SOAT1与STAR基因实时定量PCR法的检测结果上调(P<0.01),与芯片结果一致。与对照组比较,50 mg/kg纳米二氧化钛染毒60 d和100 mg/kg纳米二氧化钛染毒30、60 d小鼠卵巢组织中STAR与STAR的蛋白水平上升,差异均有统计意义(P<0.05);且随着纳米二氧化钛染毒剂量的升高和染毒时间的延长,小鼠卵巢组织中SOAT1与STAR的水平呈现上升趋势。结论纳米二氧化钛暴露通过促进小鼠卵巢组织中SOAT1与STAR的表达,干扰卵巢类固醇代谢。

Objective To understand the effects of oral intake of nano-TiO2 on the expression of sterol O-acyltransferase 1(SOAT1)and steroidogenic acute regulatory protein(STAR)in mouse ovarian tissue.Methods Forty-eight clean-grade female ICR mice aged 40 days were randomly divided into four groups,12 in each,namely the control(0.5%carboxymethyl cellulose)group and the 25,50,and 100 mg/kg nano-TiO2-treated groups,and the exposure was performed by gavage at 10 ml/kg,once a day for 60 consecutive days.Gene chip was used to detect the effects of steroid metabolism-related gene expression in ovarian tissue of mice exposed to 100 mg/kg nano-TiO2 for 60 days.Real-time quantitative PCR was used to detect the expression levels of SOAT1 and STAR genes in ovarian tissues after exposure to 100 mg/kg nano-TiO2 for 60 days.The levels of SOAT1 and STAR protein in ovarian tissue were measured by ELISA at the 15 th,30 th,and 60 th days after exposure to nano-TiO2.Results Based on the difference score≥13 or≤-13 used as the screening criteria,compared with the control group,expression of genes referring to steroid metabolism,such as Soat1,Star,Cyp17 a1 and Cyp11 a1,in ovary of mice exposed to 100 mg/kg nano-TiO2 for 60 days were up-regulated,and the expression of Cyp2 b1,Akr1 c19 and Cyp2 a5 were down-regulated.Compared with the control group,the results of real-time quantitative PCR of SOAT1 and STAR genes in the ovaries of mice exposed to 100 mg/kg nano-TiO2 for 60 days were up-regulated(P<0.01),which was consistent with the chip.Compared with the control group,both the protein levels of SOAT1 and STAR significantly increased in 50 mg/kg groups for60 days and 100 mg/kg groups for 30,60 days(P<0.05),and the levels of SOAT1 and STAR increased with increasing exposure doses and prolonged exposure time.Conclusion Nano-TiO2 exposure may interfere with ovarian steroid metabolism by promoting the expression of SOAT1 and STAR in ovarian tissue.