School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, 325035 Zhejiang, China.
Department of Pharmacy, Zhejiang Hospital, Hangzhou, 310030 Zhejiang, China.
Proc Natl Acad Sci U S A. 2020 Nov 17;117(46):29025-29034. doi: 10.1073/pnas.2010984117. Epub 2020 Nov 3.
As a physiological regulator of bile acid homeostasis, FGF19 is also a potent insulin sensitizer capable of normalizing plasma glucose concentration, improving lipid profile, ameliorating fatty liver disease, and causing weight loss in both diabetic and diet-induced obesity mice. There is therefore a major interest in developing FGF19 as a therapeutic agent for treating type 2 diabetes and cholestatic liver disease. However, the known tumorigenic risk associated with prolonged FGF19 administration is a major hurdle in realizing its clinical potential. Here, we show that nonmitogenic FGF19 variants that retain the full beneficial glucose-lowering and bile acid regulatory activities of WT FGF19 (FGF19) can be engineered by diminishing FGF19's ability to induce dimerization of its cognate FGF receptors (FGFR). As proof of principle, we generated three such variants, each with a partial defect in binding affinity to FGFR (FGF19) and its coreceptors, i.e., βklotho (FGF19) or heparan sulfate (FGF19). Pharmacological assays in WT and mice confirmed that these variants incur a dramatic loss in mitogenic activity, yet are indistinguishable from FGF19 in eliciting glycemic control and regulating bile acid synthesis. This approach provides a robust framework for the development of safer and more efficacious FGF19 analogs.
作为胆汁酸稳态的生理调节剂,FGF19 也是一种有效的胰岛素增敏剂,能够使血浆葡萄糖浓度正常化,改善血脂谱,改善脂肪肝疾病,并在糖尿病和饮食诱导的肥胖小鼠中引起体重减轻。因此,人们对开发 FGF19 作为治疗 2 型糖尿病和胆汁淤积性肝病的药物产生了浓厚的兴趣。然而,与长期 FGF19 给药相关的已知致癌风险是实现其临床潜力的主要障碍。在这里,我们表明,通过降低 FGF19 诱导其同源 FGF 受体(FGFR)二聚化的能力,可以设计出具有全长 WT FGF19(FGF19)降低血糖和调节胆汁酸活性的非有丝分裂 FGF19 变体。作为原理证明,我们生成了三种这样的变体,每个变体与 FGFR(FGF19)及其共受体βklotho(FGF19)或肝素硫酸盐(FGF19)的结合亲和力都有部分缺陷。在 WT 和 小鼠中的药理学分析证实,这些变体的有丝分裂活性显著降低,但在引起血糖控制和调节胆汁酸合成方面与 FGF19 没有区别。该方法为开发更安全、更有效的 FGF19 类似物提供了一个强大的框架。