摘要
目的探讨不同剂量的二十二碳六烯酸(DHA)对棕榈酸(PA)培养后的HepG2细胞甘油三酯和胆固醇合成的影响。方法 HepG2细胞分为无血清培养基培养的对照组和含有0.25 mmol/L PA的无血清培养基培养的PA组以及用DHA替代20%、50%、100%PA的DHA替代组。对照组和PA组培养24 h后用无酚红低糖培养基鉴定细胞是否出现胰岛素抵抗,并测定细胞内甘油三酯(TG)、胆固醇(TCH)水平;模型成立后用DHA替代20%、50%、100%PA培养12 h,再次检测细胞葡萄糖摄取量、TG和TCH水平,Western blot检测脂肪酸、胆固醇合成关键基因SREBP-1c和SREBP-2的蛋白表达水平。结果 PA处理后HepG2细胞活性明显下降,葡萄糖摄取量显著低于NC组(P<0.05),说明HepG2细胞出现胰岛素抵抗,且PA组TG、TCH水平均有不同程度的升高;用DHA替代PA后,细胞活性有所改善,葡萄糖摄取量较PA组有明显升高(P<0.05),TG、TCH水平较PA组均有不同程度的降低,并且SREBP-1c和SREBP-2表达随DHA浓度升高呈下降趋势(P<0.05)。结论 DHA可抑制SREBP-1c和SREBP-2的表达,从而抑制TG、TCH的合成,改善细胞脂代谢紊乱及胰岛素抵抗。
Objective To investigate the effects of different doses of docosahexaenoic acid （DHA） on triglyceride and cholesterol synthesis in I-IepG2 cells cultured with palmitic acid（PA）. Method HepG2 cells were divided into control group （NC） cultured in serum-free medium and 0.25 mmol/L PA containing serum-free medium PA group, respectively for DHA to replace the PA 20% , 50% and 100% DHA substitution group. The NC and PA group were cultured with phenol red free low sugar medium for 24 hours to identify the cell insulin resistance, and determined the level of triglyceride （TG） and cholesterol （TCH） in cells. After the model was established using DHA instead of PA 20% , 50% , 100% 12 h, detected the intracellular TG and TCH levels, Western blot detected the protein expression levels of SREBP-lc and SREBP-2. Result After PA treatment, the activity of HepG2 cells decreased significantly, glucose uptake was significantly lower than that of NC group （P 〈 0.05）, indicating HepG2 cell insulin resistance model was established successfully, and the PA group increased TG and TCH levels have different degree; the different concentration of DHA alternative PA, cell activity improved glucose uptake in DHA group compared with PA group there were significantly increased （P 〈 0.05） , and DHA group decreased intracellular TG and TCH levels than group PA in varying degrees, that the disorder of lipid metabolism has been improved; the expression of DHA can inhibit the SREBP-lc and SREBP-2 in cells （P 〈 0.05）, and with the increase of DHA concentration decreased. Conclusion DHA can inhibit the expression of SREBP-lc and SREBP-2, thereby inhibiting the synthesis of TG/TCH, and improve insulin resistance.
出处
《实验动物科学》
2017年第6期14-17,共4页
Laboratory Animal Science
基金
国家自然科学基金面上项目(No.31272386)
关键词
DHA
胰岛素抵抗
脂类合成
蛋白表达
DHA
insulin resistance
lipid synthesis
protein expression
