Impact of Clinically Relevant Mutations on the Pharmacoregulation and Signaling Bias of the Calcium-Sensing Receptor by Positive and Negative Allosteric Modulators
Impact of Clinically Relevant Mutations on the Pharmacoregulation and Signaling Bias of the Calcium-Sensing Receptor by Positive and Negative Allosteric Modulators
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DOI：
10.1210/en.2012-1887
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发表时间：
2013-03-01
期刊：
影响因子：
4.8
通讯作者：
Christopoulos, Arthur
中科院分区：
文献类型：
--
作者：
Leach, Katie;Wen, Adriel;Christopoulos, Arthur
西那卡塞主要用于治疗终末期肾衰竭引起的继发性甲状旁腺功能亢进症，但最近，其治疗钙敏感受体（CaSR）功能丧失突变患者的潜在临床疗效已得到认可。许多临床相关的 CaSR 突变位于受体的七螺旋跨膜和细胞外环区域，预计变构调节剂将在此处结合。本研究的目的是研究此类突变对正变构调节剂西那卡塞和负变构调节剂 NPS-2143 分别对 CaSR 的药物调节的影响。西那卡塞和 NPS-2143 都有效地拯救了细胞表面表达严重受损的突变体，这表明这两类药物都可以稳定受体构象，从而更有效地运输到细胞表面。此外，几乎所有突变型 CaSR 的功能损伤都可以通过西那卡塞或 NPS-2143 通过恢复细胞内信号传导来挽救。与 ERK1/2 磷酸化相比，这两种化合物调节激动剂刺激的细胞内 Ca2+ 动员的能力明显更强，表明变构调节剂在激动剂刺激的 CaSR 信号传导中对不同途径产生偏差。三个突变（G（670）R，（PR）-R-748和（LR）-R-773）改变了变构调节剂与CaSR的结合亲和力，并且3个突变（（VI）-I-817，（LR）-R-773和（EK）-K-767）改变了变构调节剂和Ca-o（2+）之间的协同性。这些发现对于使用变构 CaSR 调节剂治疗与 CaSR 突变相关的疾病以及分析突变对 CaSR 功能和药物调节的影响具有重要意义。 （内分泌学154：1105-1116，2013）
Cinacalcet is predominantly used to treat secondary hyperparathyroidism due to end-stage renal failure, but, more recently, its potential clinical efficacy in treating patients with loss-of-function mutations in the calcium-sensing receptor (CaSR) has been recognized. Many clinically relevant CaSR mutations are located in the heptahelical membrane spanning and extracellular loop regions of the receptor, where allosteric modulators are predicted to bind. The aim of the present study was to investigate the impact of such mutations on the pharmacoregulation of the CaSR by the positive and negative allosteric modulators, cinacalcet and NPS-2143, respectively. Both cinacalcet and NPS-2143 effectively rescued mutants whose cell surface expression was substantially impaired, suggesting that both classes of drug can stabilize a receptor conformation that is trafficked more effectively to the cell surface. In addition, functional impairments in almost all mutant CaSRs were rescued by either cinacalcet or NPS-2143 via restoration of intracellular signaling. There was a significantly greater ability of both compounds to modulate agonist-stimulated intracellular Ca2+ mobilization than ERK1/2 phosphorylation, indicating that the allosteric modulators engender bias in agonist-stimulated CaSR signaling to different pathways. Three mutations (G(670)R, (PR)-R-748, and (LR)-R-773) altered the binding affinity of allosteric modulators to the CaSR, and 3 mutations ((VI)-I-817, (LR)-R-773, and (EK)-K-767) altered the cooperativity between the allosteric modulator and Ca-o(2+). These findings have important implications for the treatment of diseases associated with CaSR mutations using allosteric CaSR modulators and for analyzing the effects of mutations on the function and pharmacoregulation of the CaSR. (Endocrinology 154: 1105-1116, 2013)