Recent work indicates a role for RING finger protein 11 (RNF11) in Parkinson disease (PD) pathology, which involves the loss of dopaminergic neurons. However, the role of RNF11 in regulating dopamine neurotransmission has not been studied. In this work, we tested the effect of RNF11 RNAi knockdown or overexpression on stimulated dopamine release in the larval Drosophila central nervous system. Dopamine release was stimulated using optogenetics and monitored in real-time using fast-scan cyclic voltammetry at an electrode implanted in an isolated ventral nerve cord. RNF11 knockdown doubled dopamine release, but there was no decrease in dopamine from RNF11 overexpression. RNF11 knockdown did not significantly increase stimulated serotonin or octopamine release, indicating the effect is dopamine specific. Dopamine clearance was also changed, as RNF11 RNAi flies had a higher V_max and RNF11 overexpressing flies had a lower V_max than control flies. RNF11 RNAi flies had increased mRNA levels of dopamine transporter (DAT) in RNF11, confirming changes in DAT. In RNF11 RNAi flies, release was maintained better for stimulations repeated at short intervals, indicating increases in the recycled releasable pool of dopamine. Nisoxetine, a DAT inhibitor, and flupenthixol, a D2 antagonist, did not affect RNF11 RNAi or overexpressing flies differently than control. Thus, RNF11 knockdown causes early changes in dopamine neurotransmission, and this is the first work to demonstrate that RNF11 affects both dopamine release and uptake. RNF11 expression decreases in human dopaminergic neurons during PD, and that decrease may be protective by increasing dopamine neurotransmission in the surviving dopaminergic neurons.

最近的研究表明环指蛋白 11 (RNF11) 在帕金森病 (PD) 病理学中的作用，这涉及多巴胺能神经元的丧失。然而，尚未研究 RNF11 在调节多巴胺神经传递中的作用。在这项工作中，我们测试了RNF11 RNAi 敲低或过表达对果蝇幼虫中枢神经系统刺激多巴胺释放的影响。使用光遗传学刺激多巴胺释放，并使用快速扫描循环伏安法在植入孤立腹神经索的电极上实时监测。RNF11敲低使多巴胺释放增加一倍，但RNF11过表达导致多巴胺没有减少。RNF11击倒并没有显着增加刺激的血清素或章鱼胺的释放，表明效果是多巴胺特异性的。多巴胺清除率也发生了变化，因为RNF11 RNAi 果蝇的V _max较高，而RNF11过表达果蝇的V _max比对照果蝇低。RNF11 RNAi 果蝇在RNF11中增加了多巴胺转运蛋白 (DAT) 的 mRNA 水平，证实了 DAT 的变化。在RNF11 RNAi 果蝇中，对于以短间隔重复的刺激，释放保持得更好，表明多巴胺的可回收可释放池增加。DAT 抑制剂尼索西汀和 D2 拮抗剂氟哌噻吨不影响RNF11 RNAi 或过表达的苍蝇与对照不同。因此，RNF11 敲低导致多巴胺神经传递的早期变化，这是第一个证明 RNF11 影响多巴胺释放和摄取的工作。PD 期间人类多巴胺能神经元中的 RNF11 表达降低，这种降低可能通过增加存活的多巴胺能神经元中的多巴胺神经传递来起到保护作用。