黄连素对衣霉素诱导的3T3-L1脂肪细胞胰岛素抵抗的影响

Effect of berberine on insulin resistance of 3T3-L1 adipocytes induced by tunicamycin

目的探讨黄连素对内质网应激(ERS)诱导剂衣霉素诱导的3T3-L1脂肪细胞胰岛素抵抗(IR)的影响及可能机制。方法体外诱导分化成熟的3T3-L1细胞,分别用衣霉素和黄连素干预。采用MTT法检测细胞生存率,葡萄糖氧化酶法检测3T3-L1细胞的葡萄糖消耗量,Western blot法检测3T3-L1细胞不同干预条件下ERS信号标志蛋白蛋白激酶R样内质网激酶(PERK)、磷酸化PERK(p-PERK)、真核生物翻译起始因子2α亚基(eIF2α)和磷酸化eIF2α(p-eIF2α)的表达。结果胰岛素刺激的3T3-L1细胞葡萄糖消耗量可因衣霉素5 mg/L作用5 h后减少(P<0.05);黄连素20μmol/L预处理24 h可拮抗衣霉素诱导的3T3-L1细胞的IR(P<0.05)。衣霉素5 mg/L作用5 h后,p-PERK和p-eIF2α蛋白表达增加(P<0.05);而黄连素预处理24 h可降低衣霉素诱导的p-PERK和p-eIF2α蛋白表达(P<0.05)。结论黄连素可改善ERS引起的3T3-L1细胞IR,其机制可能与其抑制PERK/eIF2α通路的激活有关。

Objective To explore the effect of berberine on endoplasmic reticulum stress(ERS) inducer tunicamycin-induced insulin resistance(IR) of 3 T3-L1 adipocytes and its possible mechanism.Methods The differentiation mature 3 T3-L1 adipocytes induced in vitro were treated with tunicamycin and berberine, respectively.The cell viability was measured by MTT assay.The glucose consumption was determined by glucose oxidase assay to evaluate insulin sensitivity of 3 T3-L1 adipocytes with different interventions.Western blot was performed to determine the expressions of protein kinase R-like endoplasmic reticulum kinase(PERK) and eukaryotic translation initiation factor 2 alpha subunit(eIF2α) in 3 T3-L1 adipocytes.Results The incubation of tunicamycin 5 mg/L for 5 hours reduced insulin-stimulated glucose consumption in 3 T3-L1 adipocytes(P<0.05),which was inhibited by the pretreatment of berberine 20 μmol/L for 24 hours(P<0.05).The protein expressions of phosphorylated PERK(p-PERK) and phosphorylated eIF2α(p-eIF2α) in the 3 T3-L1 adipocytes were increased by an incubation of tunicamycin 5 mg/L for 5 hours(P<0.05),which were reduced by berberine pretreatment for 24 hours(P<0.05).Conclusion Berberine is able to improve ERS-mediated IR in 3 T3-L1 adipocytes, which may be related to the inhibition of PERK/eIF2α pathway activation.