小檗碱抑制NF-κB p65改善肝脏糖异生的作用研究

Study on berberine restrains hepatic gluconeogenesis via inhibiting NF-κB p65 activity

目的:观察小檗碱对核转录因子NF-κB p65蛋白活性的影响,探究小檗碱改善cAMP/PKA肝脏糖异生信号的作用及机制。方法:雄性ICR小鼠随机分为正常对照组、胰高血糖素模型组和小檗碱组,每组8只。采用小鼠腹腔注射胰高血糖素模型来观察小檗碱对糖异生信号的影响。RT-PCR法定量检测肝组织中糖异生关键酶PGC-1α、G6Pase和PEPCK基因表达。Western Blot法检测肝组织中p-P65(Ser468)、PDE4B和p-PKA substrate蛋白表达,检测肝组织细胞核中Ac-P65(Lys310)、p65及细胞胞浆中Ac-P65(Lys310)的蛋白表达。结果:小檗碱可明显抑制肝组织中p65蛋白活性及其细胞核转位,增加PDE4B蛋白表达,减少胰高血糖素介导的PKA底物水平磷酸化和肝糖异生关键酶的基因表达(P<0.05,P<0.01)。结论:小檗碱能够通过抑制NF-κB p65的蛋白活性阻断cAMP/PKA信号,从而改善胰高血糖素介导的肝脏糖异生。

Objective:To observe the role of berberine on the activity of nuclear transcription factor NF-κB p65,and to explore the effect and mechanism of berberine on the hepatic cAMP/PKA gluconeogenesis signaling.Methods:Male ICR mice were randomly divided into control group,glucagon model group and berberine group.Mice intraperitoneally injection of glucagon were used to investigate the role of berberine on the gluconeogenesis signaling.Gene expressions of key gluconeogenic enzymes PGC-1α,G6 Pase and PEPCK in the liver tissue were detected by RT-PCR.The protein expressions of p-P65(Ser468),PDE4 B and p-PKA substrate in the liver tissue were assayed with Western blot.Besides,nuclear Ac-P65(Lys310),p65 expressions and cytosol Ac-P65(Lys310)expression in the liver tissue were examined.Results:Berberine significantly inhibited p65 protein activity and its nuclear translocation in the liver tissue,increased PDE4 B protein expression and thus reduced glucagon-mediate PAK substrates phosphorylation and gene expressions of key gluconeogenic enzymes.Conclusion:Berberine blocked cAMP/PKA signaling via inhibiting NF-κB p65 protein activity,and thus alleviated glucagon-driven hepatic gluconeogenesis.