Cohen Sophie R, Xu Wei, Aziz Nastaran F, España Rodrigo A, Kortagere Sandhya
Dept. of Neurobiology & Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, United States.
Dept. of Microbiology & Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, United States.
ACS Chem Neurosci. 2025 Jul 16;16(14):2579-2591. doi: 10.1021/acschemneuro.5c00076. Epub 2025 Jun 26.
Cocaine use disorder is a major healthcare issue with no effective FDA-approved treatments. Cocaine exerts its effects - in part - by blocking dopamine transporters (DAT) and subsequently dysregulating DAT function. Several molecular targets have been identified as key regulators of DAT function and expression including dopamine D3 receptors (D3R) that are highly expressed in the mesolimbic dopamine pathway. Although D3R partial agonists and antagonists have been shown to influence cocaine seeking in rodents, effects have been inconsistent with studies reporting varying outcomes on cocaine-associated behavior. In this study, we tested the effects of SK609, a novel G-protein biased D3R agonist, and pramipexole, an unbiased agonist of D3R, on DAT expression and function and cocaine-seeking behavior. Results indicated that SK609 reduced phosphorylation of DATs following cocaine and the uptake inhibition effects of cocaine on dopamine transmission in and studies, respectively. By comparison, pramipexole augmented the effects of cocaine on DAT phosphorylation, enhanced dopamine levels, and increased cocaine seeking in rats. These results suggest that unbiased D3R activation promotes the effects of cocaine and that limiting D3R agonists to G-protein signaling pathways may have the potential to reduce these effects.
可卡因使用障碍是一个重大的医疗保健问题,目前尚无美国食品药品监督管理局(FDA)批准的有效治疗方法。可卡因发挥其作用的部分方式是通过阻断多巴胺转运体(DAT),进而使DAT功能失调。已确定几个分子靶点是DAT功能和表达的关键调节因子,包括在中脑边缘多巴胺通路中高表达的多巴胺D3受体(D3R)。尽管D3R部分激动剂和拮抗剂已被证明会影响啮齿动物对可卡因的觅求行为,但这些研究结果并不一致,不同研究报告了对可卡因相关行为的不同结果。在本研究中,我们测试了新型G蛋白偏向性D3R激动剂SK609和非偏向性D3R激动剂普拉克索对DAT表达和功能以及可卡因觅求行为的影响。结果表明,在体内和体外研究中,SK609分别降低了可卡因给药后DAT的磷酸化水平以及可卡因对多巴胺传递的摄取抑制作用。相比之下,普拉克索增强了可卡因对DAT磷酸化的作用,提高了多巴胺水平,并增加了大鼠对可卡因的觅求行为。这些结果表明,非偏向性激活D3R会促进可卡因的作用,而将D3R激动剂限制于G蛋白信号通路可能有降低这些作用的潜力。