The nuclear receptor PPARγ is the target of thiazolidinedione antidiabetics including rosiglitazone and pioglitazone. These full PPARγ agonists are effective and well tolerated in most patients, but cause fluid retention and weight gain in a minority. In this proof-of-concept study, Choi et al. show the development of specific PPARγ ligands that retain antidiabetic activity through blockade of Cdk5-mediated PPARγ phosphorylation, but that are not full PPARγ agonists. In mouse models, these ligands do not cause the side effects sometimes associated with full PPARγ agonists. PPARγ is the functioning receptor for the thiazolidinedione (TZD) class of antidiabetes drugs including rosiglitazone and pioglitazone1. These drugs are full classical agonists for this nuclear receptor, but recent data have shown that many PPARγ-based drugs have a separate biochemical activity, blocking the obesity-linked phosphorylation of PPARγ by Cdk5 (ref. 2). Here we describe novel synthetic compounds that have a unique mode of binding to PPARγ, completely lack classical transcriptional agonism and block the Cdk5-mediated phosphorylation in cultured adipocytes and in insulin-resistant mice. Moreover, one such compound, SR1664, has potent antidiabetic activity while not causing the fluid retention and weight gain that are serious side effects of many of the PPARγ drugs. Unlike TZDs, SR1664 also does not interfere with bone formation in culture. These data illustrate that new classes of antidiabetes drugs can be developed by specifically targeting the Cdk5-mediated phosphorylation of PPARγ.
核受体
PPARγ 是包括
罗格列酮和
吡格列酮在内的
噻唑烷二
酮类抗糖尿病药物的靶点。这些全
PPARγ 激动剂对大多数患者有效且耐受性良好,但对少数患者会导致体液潴留和体重增加。在这项概念验证研究中,Choi 等人展示了通过阻断 Cdk5 介导的
PPARγ
磷酸化而保持抗糖尿病活性的特定
PPARγ
配体的开发情况,但这些
配体并非完全的
PPARγ 激动剂。在小鼠模型中,这些
配体不会产生完全
PPARγ 激动剂有时会产生的副作用。
PPARγ 是
噻唑烷二酮(TZD)类抗糖尿病药物(包括
罗格列酮和
吡格列酮1)的功能受体。这些药物是该核受体的完全经典激动剂,但最近的数据显示,许多基于
PPARγ 的药物具有单独的生化活性,即通过 Cdk5 阻止与肥胖相关的
PPARγ
磷酸化(参考文献 2)。在这里,我们描述了一些新型合成化合物,它们与
PPARγ 的结合方式独特,完全没有经典的转录激动作用,而且能在培养的脂肪细胞和
胰岛素抵抗小鼠体内阻断 Cdk5 介导的
磷酸化。此外,其中一种化合物 SR1664 具有很强的抗糖尿病活性,同时不会导致体液潴留和体重增加,而这正是许多
PPARγ 药物的严重副作用。与 TZDs 不同,SR1664 也不会干扰培养物中骨的形成。这些数据说明,通过特异性靶向 Cdk5 介导的
PPARγ
磷酸化,可以开发出新的抗糖尿病药物。