基于CYP3A等CYP450酶活性诱导诠释阿托伐他汀等他汀类药物诱发新生糖尿病和加重糖尿病症状的作用及机制

Clinical reports have showed that atorvastatin, simvastatin and rosuvastatin with strong CYP3A induction may induce new onset diabetes and deteriorate diabetes, but pravastatin and pitavastatin without CYP3A induction little affect glucose metabolism. A new hypothesis was raised as follows. The induction of CYP3A etc CYP450s may be one of the reasons that statins including atorvastatin induced new onset diabetes and deteriorated diabetes. A series of experiments were designed to verify the hypothesis. Mild diabetic and type 2 diabetic rats were used to investigate the relationship between the statin-induced CYP450s and their diabetogenic effects, which was further verified using gene knock-out mice. Both hepatic and islet cells were used to investigated CYP450 induction, oxidative stress and insulin resistance by statins. The cross-talk between the statin-induced CYP450s and PEPCK or G-6-Pase also was investigated and further verified using gene silencing and transfection. The results may highlight roles of statin-induced CYP450s and their diabetogenic effects, as well as give gudainces for clinical medication and drug design of new statins.

鉴于具有诱发和加重糖尿病的阿托伐他汀、辛伐他汀和瑞舒伐他汀有强CYP3A等CYP450酶诱导作用，而不具有这种不良反应的普伐他汀和匹伐他汀无CYP3A酶诱导作用的事实，在前期工作基础上提出"CYP3A等CYP450酶诱导是阿托伐他汀等他汀类药物诱发和加重糖尿病原因之一"的推论。用亚糖尿病大鼠和2型糖尿病大鼠比较几种他汀药物的 CYP3A等CYP450酶诱导与其诱发和加重糖尿病关系，分析CYP3A等CYP450酶诱导在他汀类药物诱发和加重糖尿病中作用及机制，并用基因敲除小鼠验证。在细胞中研究他汀类引起CYP3A诱导与氧化应激、糖代谢受损和胰岛素释放抑制关系，以及他汀介导的CYP3A酶诱导与PEPCK和G-6-Pase间交互作用，用基因转染和沉默验证。其成果对于阐明CYP3A 等CYP450酶诱导在阿托伐他汀等他汀类药物诱发和加重糖尿病中的作用和机制，临床用药以及新型他汀类药物研发有重要意义。

他汀类药物是预防动脉粥样-心血管疾病的首选治疗方案。但近年来临床报道显示他汀类具有诱发新生糖尿病和加重糖尿病的风险其机制不清。我们的研究证实阿托伐他汀损伤HepG2肝细胞的糖利用，下调糖利用关键蛋白GCK和糖摄取蛋白GLUT2的表达。PXR的抑制剂白藜芦醇等或者沉默PXR基因逆转阿托伐他汀对糖利用和糖摄取的损伤作用。转染PXR基因下调HepG2细胞中GLUT2和GCK的蛋白表达，阿托伐他汀加强转染PXR基因对GLUT2和GCK的蛋白表达的抑制作用。动物实验也表明阿托伐他汀损伤高脂大鼠糖耐量，阿托伐他汀下调高脂饲养大鼠肝脏中GCK和GLUT2的蛋白表达，但上调高脂饲养大鼠肝脏中PXR和CYP3A1的蛋白表达。阿托伐他汀激活肝PXR，抑制GLUT2和GCK的活性与表达，使肝细胞糖代谢受损。这可能是他汀类药物诱发和加重糖尿病的机制之一。.研究还发现在小鼠成肌细胞C2C12中阿托伐他汀损伤肌细胞对糖利用和糖摄取，这种损伤作用与抑制C2C12细胞GLUT4转位降低有关。合用胆固醇或甲羟戊酸可逆转阿托伐他汀引起的糖代谢和GLUT4膜转位损伤。Beta-环糊精剥离胆固醇也获得类似阿他伐汀损伤糖代谢和GLUT4膜转位的作用，添加胆固醇逆转Beta -环糊精的作用。阿托伐他汀给药损伤高脂喂养小鼠的糖耐量和胰岛素耐量。阿托伐他汀不影响肌肉组织中总GLUT4蛋白表达，但显著降低细胞膜中GLUT4的蛋白表达。且这种糖耐量和GLUT4膜表达损伤与肌肉组织中游离胆固醇的水平呈负相关。阿托伐他汀降低胆固醇的作用会导致肌肉细胞中GLUT4膜转移减少，是阿托伐他汀损伤肌肉细胞糖耐量的原因之一。.进一步研究证实阿托伐他汀加重糖尿病大鼠的肝损伤和肝脏氧化应激，阿托伐他汀也可以增加正常大鼠和苯巴比妥诱导大鼠的肝毒性，这可能与Cyp3a诱导有关。体外研究结果表明阿托伐他汀在糖尿病大鼠原代肝细胞上的摄取增加，代谢增强。Cyp3a抑制剂酮康唑、Oatp2抑制剂吉非贝齐和ROS清除剂谷胱甘肽等逆转阿托伐他汀导致的糖尿病大鼠原代肝细胞中ROS水平的升高以及细胞毒性。siRNA抑制HepG2细胞中OATP1B1和CYP3A4的表达逆转阿托伐他汀导致的细胞毒性和ROS水平增加。阿托伐他汀在糖尿病大鼠中肝毒性显著增强，与糖尿病状态下肝脏CYP3A和OATP2功能与表达诱导，在代谢阿托伐他汀过程中大量生成氧化应激产物有关。