Beggiato Sarah, Borelli Andrea C, Tomasini Maria C, Castelli M Paola, Pintori Nicholas, Cacciaglia Roberto, Loche Antonella, Ferraro Luca
Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.
IRET Foundation, Bologna, Italy.
Front Pharmacol. 2018 Apr 5;9:327. doi: 10.3389/fphar.2018.00327. eCollection 2018.
The present study was aimed to further characterize the pharmacological profile of N-[4-(trifluoromethyl) benzyl]-4-methoxybutyramide (GET73), a putative negative allosteric modulator (NAM) of metabotropic glutamate subtype 5 receptor (mGluR5) under development as a novel medication for the treatment of alcohol dependence. This aim has been accomplished by means of a series of functional assays. These assays include the measure of several down-stream signaling [intracellular Ca levels, inositol phosphate (IP) formation and CREB phosphorylation (pCREB)] which are generally affected by mGluR5 ligands. In particular, GET73 (0.1 nM-10 μM) was explored for its ability to displace the concentration-response curve of some mGluR5 agonists/probes (glutamate, L-quisqualate, CHPG) in different native preparations. GET73 produced a rightward shift of concentration-response curves of glutamate- and CHPG-induced intracellular Ca levels in primary cultures of rat cortical astrocytes. The compound also induced a rightward shift of concentration response curve of glutamate- and L-quisqualate-induced increase in IP turnover in rat hippocampus slices, along with a reduction of CHPG (10 mM)-induced increase in IP formation. Moreover, GET73 produced a rightward shift of concentration-response curve of glutamate-, CHPG- and L-quisqualate-induced pCREB levels in rat cerebral cortex neurons. Although the engagement of other targets cannot be definitively ruled out, these data support the view that GET73 acts as an mGluR5 NAM and support the significance of further investigating the possible mechanism of action of the compound.
本研究旨在进一步表征N-[4-(三氟甲基)苄基]-4-甲氧基丁酰胺（GET73）的药理学特性。GET73是一种正在开发的代谢型谷氨酸受体5亚型（mGluR5）的假定负变构调节剂（NAM），作为治疗酒精依赖的新型药物。这一目标已通过一系列功能测定得以实现。这些测定包括测量几种下游信号[细胞内钙水平、肌醇磷酸（IP）形成和CREB磷酸化（pCREB）]，这些信号通常受mGluR5配体影响。特别是，研究了GET73（0.1 nM - 10 μM）在不同天然制剂中取代某些mGluR5激动剂/探针（谷氨酸、L-喹啉酸、CHPG）浓度-反应曲线的能力。GET73使大鼠皮质星形胶质细胞原代培养物中谷氨酸和CHPG诱导的细胞内钙水平的浓度-反应曲线向右移动。该化合物还使大鼠海马切片中谷氨酸和L-喹啉酸诱导的IP周转率增加的浓度反应曲线向右移动，同时降低了CHPG（10 mM）诱导的IP形成增加。此外，GET73使大鼠大脑皮质神经元中谷氨酸、CHPG和L-喹啉酸诱导的pCREB水平的浓度-反应曲线向右移动。尽管不能完全排除其他靶点的参与，但这些数据支持GET73作为mGluR5 NAM的观点，并支持进一步研究该化合物可能作用机制的重要性。
