α-亚麻酸对猪颗粒细胞胆固醇合成、类固醇激素合成和凋亡的影响

Effects of α-Linolenic Acid on Cholesterol Synthesis,Steroid Hormone Synthesis and Apoptosis of Porcine Granulosa Cells

本试验旨在探究α-亚麻酸(ALA)对猪颗粒细胞(GCs)胆固醇合成、类固醇激素合成和凋亡的影响。试验收集150日龄健康母猪卵巢GCs,通过酶联免疫吸附试验(ELISA)、实时荧光定量PCR(RT-PCR)、Western blot和流式细胞术探究ALA对猪GCs胆固醇合成、类固醇激素分泌及其凋亡的影响。结果表明:1)50μmol/L ALA处理极显著抑制了雌二醇(E_(2))的合成(P<0.01),但对孕酮(P_4)的合成没有显著影响(P>0.05);2)50μmol/L ALA处理显著下调了胆固醇侧链裂解酶(CYP11A1)和3β-羟基类固醇脱氢酶(3β-HSD)的mRNA相对表达量(P<0.05),同时显著下调了CYP11A1和类固醇激素合成急性调节蛋白(StAR)的蛋白相对表达量(P<0.05);3)50μmol/L ALA处理显著下调了关键胆固醇合成基因3-羟基-3-甲基戊二酰辅酶A还原酶(HMGCR)、清道夫受体B类成员1 (SCARB1)和胆固醇调节元件结合蛋白2(SREBP2)的mRNA相对表达量(P<0.05);4)50μmol/L ALA处理显著增加了活细胞的数量(P<0.05),显著上调了B细胞淋巴瘤/白血病-2(Bcl-2)的mRNA相对表达量(P<0.05),并显著下调了B细胞淋巴瘤/白血病-2相关X蛋白(Bax)的蛋白相对表达量(P<0.05)。由此可见,ALA通过抑制胆固醇的合成来抑制类固醇激素的合成,并且抑制GCs的凋亡。

The aim of this study was to explore the effects ofα-linolenic acid(ALA)on cholesterol synthesis,steroid hormone synthesis and apoptosis of porcine granulosa cells(GCs).Ovarian GCs of 150-day-old healthy sows were collected and the enzyme linked immunosorbent assay(ELISA),real-time fluorescence quantitative PCR(RT-PCR),Western blot and flow cytometry were used to investigate the effects of ALA on cholesterol synthesis,steroid secretion and apoptosis of porcine GCs.The results showed as follows:1)50μmol/L ALA treatment extremely significantly inhibited the synthesis of estradiol(E_(2))(P<0.01),but had no significant effect on the synthesis of progesterone(P 4)(P>0.05).2)50μmol/L ALA treatment significantly down-regulated the mRNA relative expression levels of cholesterol side-chain cleavage enzyme(CYP11A1)and 3β-hydroxy steroid dehydrogenase(3β-HSD)(P<0.05),and significantly down-regulated the protein relative expression levels of CYP11A1 and steroidogenic acute regulatory protein(StAR)(P<0.05).3)50μmol/L ALA treatment significantly down-regulated the mRNA relative expression levels of key cholesterol synthesis genes,including 3-hydroxy-3-methylglutaryl-CoA reductase(HMGCR),scavenger receptor class B type 1(SCARB1)and sterol regulatory element-binding protein 2(SREBP2)(P<0.05).4)50μmol/L ALA treatment significantly increased the number of live cells(P<0.05),significantly up-regulated the B-cell lymphoma/leukemia-2(Bcl-2)mRNA relative expression level(P<0.05),and significantly down-regulated the B-cell lymphoma/leukemia-2 associated X protein(Bax)protein relative expression level(P<0.05).It can be seen that ALA inhibits the synthesis of steroids and apoptosis of GCs by inhibiting the synthesis of cholesterol.