Selectivity and Anti-Parkinson's Potential of Thiadiazolidinone RGS4 Inhibitors
Selectivity and Anti-Parkinson's Potential of Thiadiazolidinone RGS4 Inhibitors
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DOI：
10.1021/acschemneuro.5b00063
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发表时间：
2015-06-01
影响因子：
5
通讯作者：
Neubig, Richard R.
中科院分区：
文献类型：
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作者：
Blazer, Levi L.;Storaska, Andrew J.;Neubig, Richard R.
目前许多治疗针对G蛋白偶联受体（GPCR）、转运体或离子通道。除了直接靶向这些蛋白质外，破坏定位或调节其功能的蛋白质-蛋白质相互作用可以增强选择性并提供独特的药理作用。G蛋白信号（RGS）蛋白的调节因子，特别是RGS4，在癫痫和帕金森病中发挥重要作用。噻二唑烷酮（Thiadiazolidinone， TDZD）抑制剂是RGS4体外生化作用的纳摩尔效阻滞剂。在这里，我们证明了CCG-203769对RGS4的选择性比其他RGS蛋白高（8到5000倍）。它对RGS4的选择性是同类化学支架的另一个靶点GSK-3 β的300倍。CCG-203769不抑制100 μ m的半胱氨酸蛋白酶木瓜蛋白酶。CCG-203769以rgs4依赖的方式增强G α (q)依赖的细胞Ca2+信号传导。TDZD抑制剂还可以增强SH-SY-5Y细胞中G α (i)依赖性的δ - or抑制cAMP产生，SH-SY-5Y细胞表达内源性受体和RGS4。重要的是，CCG-203769在体内增强了已知的G α (i)依赖性毒蕈碱性心动过缓的RGS4机制。此外，它还能逆转raclopride诱导的小鼠运动障碍和运动迟缓，这是帕金森病运动障碍的一些方面的模型。对复合效应的广泛评估显示，在抑制细胞RGS4所需的浓度下，脱靶效应最小。这些结果扩大了我们对TDZD RGS抑制剂的机制和特异性的理解，并支持了RGS蛋白治疗帕金森病和其他神经疾病的潜力。
Many current therapies target G protein coupled receptors (GPCR), transporters, or ion channels. In addition to directly targeting these proteins, disrupting the protein protein interactions that localize or regulate their function could enhance selectivity and provide unique pharmacologic actions. Regulators of G protein signaling (RGS) proteins, especially RGS4, play significant roles in epilepsy and Parkinson's disease. Thiadiazolidinone (TDZD) inhibitors of RGS4 are nanomolar potency blockers of the biochemical actions of RGS4 in vitro. Here, we demonstrate the substantial selectivity (8- to >5000-fold) of CCG-203769 for RGS4 over other RGS proteins. It is also 300-fold selective for RGS4 over GSK-3 beta another target of this class of chemical scaffolds. It does not inhibit the cysteine protease papain at 100 mu M. CCG-203769 enhances G alpha(q)-dependent cellular Ca2+ signaling in an RGS4-dependent manner. TDZD inhibitors also enhance G alpha(i)-dependent delta-OR inhibition of cAMP production in SH-SY-5Y cells, which express endogenous receptors and RGS4. Importantly, CCG-203769 potentiates the known RGS4 mechanism of G alpha(i)-dependent muscarinic bradycardia in vivo. Furthermore, it reverses raclopride-induced akinesia and bradykinesia in mice, a model of some aspects of the movement disorder in Parkinson's disease. A broad assessment of compound effects revealed minimal off-target effects at concentrations necessary for cellular RGS4 inhibition. These results expand our understanding of the mechanism and specificity of TDZD RGS inhibitors and support the potential for therapeutic targeting of RGS proteins in Parkinson's disease and other neural disorders.