油酸对3T3-L1脂肪细胞脂联素及CDK5、PPARγ表达的调节作用

EFFECTS OF OLEIC ACID ON THE EXPRESSIONS OF ADIPONECTIN,CDK5 AND PPARγIN 3T3-L1 ADIPOCYTES

目的探讨不同浓度油酸对3T3-L1脂肪细胞脂联素及细胞周期性依赖激酶5(CDK5)、过氧化物酶体增殖物激活受体经(PPARy)表达的调节作用。方法用不同浓度(25、50、100、200、400μmol/L)油酸处理诱导成熟的3T3-L1脂肪细胞24h,用实时荧光定量PCR及Western-blotting法测定各处理组胞内脂联素、CDK5、PPARy mRNA和蛋白表达水平,并在油酸浓度为100、400μmol/L时用Western-blotting法测定PPARγ^(ser273)磷酸化水平。结果50~100μmol/L范围内,油酸可促进脂联素、PPARy mRNA表达,100μmol/L油酸可显著上调脂联素和PPAR;mRNA及蛋白表达;之后随浓度增加,油酸对脂联素和PPARy的促进作用下降,在400μmol/L时显著降低脂联素mRNA和蛋白表达,但对PPARγ蛋白无明显作用。100μmol/L油酸对PPARγ^(ser273)磷酸化水平无明显影响,但在400μmol/L时可显著升高PPARγ^(ser273)磷酸化水平。各浓度油酸对CDK5 mRNA及蛋白均无明显影响。结论50~100μmol/L油酸可促进脂联素、PPARγ表达,400μmol/L油酸抑制脂联素的表达并升高PPARγ^(ser273)磷酸化水平。提示50~100μmol/L油酸可能通过上调PPARγ而促进脂联素表达,400μmol/L油酸可能通过异常激活CDK5介导的PPARγ^(ser273)磷酸化抑制脂联素表达。

Objective To explore the effects adiponectin, cyclin-dependent kinase 5 （CDK5） and of different concentrations of oleic acid on the expressions of peroxisome proliferator-activated receptor-y （PPARy） in 3T3-L1 adipocytes. Methods 3T3-L1 adipocytes were incubated with 25, 50, 100, 200, 400 μmol/L oleic acid for 24h. The mRNA and protein expressions of adiponectin, CDK5 and PPARy were determined by real-time PCR and Western-blotting. The level of PPARyser273 phosphorylation was determined by Western-blotting after 3T3-L1 adipocytes were incubated with 100 or 400μmol/L oleic acid. Result Oleic acid could significantly increase the expression of adiponectin and PPAR7 mRNA at the concentrations of 50-100μmol/L. Oleic acid also significantly increased the protein expression of adiponectin and PPAR7 at 100μmol/L. The improved effects were decreased with the rise of the concentration of oleie acid. Oleic acid at 400μmol/L significantly decreased the expression of adiponectin mRNA and protein, but no change of PPARy protein expression was noted. Oleic acid didn＇t change the level of PPARyser273 phosphorylation at 100μmol/L, but significantly increased its expression at 400 μmol/L. CDK5 expression was not changed by oleic acid. Conclusion Oleic acid at 50-100μmol/L can raise adiponectin and PPARy expression, while 400μmol/L oleic acid can decrease adiponectin expression and increase the level of PPARyscr273 phosphorylation. Our results demonstrate that 50-100μmol/L oleic acid may increase the expression of adiponectin by up-regulating the expression of PPARy, but 400μmol/L oleic acid may decrease the expression of adiponectin by PPAR7ser273 phosphorylation mediated by CDK5. [ACTA NUTRIMENTA SINICA, 2016, 38（6）： 556-5601