Privman Champaloux Eve, Donelson Nathan, Pyakurel Poojan, Wolin Danielle, Ostendorf Leah, Denno Madelaine, Borman Ryan, Burke Chris, Short-Miller Jonah C, Yoder Maria R, Copeland Jeffrey M, Sanyal Subhabrata, Venton B Jill
Neuroscience Graduate Program and Medical Scientist Training Program, University of Virginia, Charlottesville, VA, United States.
Biogen-Idec, Cambridge, MA, United States.
Neuroscience. 2021 Jan 1;452:37-48. doi: 10.1016/j.neuroscience.2020.10.021. Epub 2020 Nov 8.
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 and RNF11 overexpressing flies had a lower V 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.
近期研究表明，泛素连接酶11（RNF11）在帕金森病（PD）病理过程中发挥作用，该病理过程涉及多巴胺能神经元的丧失。然而，RNF11在调节多巴胺神经传递中的作用尚未得到研究。在本研究中，我们测试了RNF11 RNA干扰敲低或过表达对果蝇幼虫中枢神经系统中刺激诱导的多巴胺释放的影响。使用光遗传学刺激多巴胺释放，并通过植入孤立腹神经索的电极上的快速扫描循环伏安法实时监测。RNF11敲低使多巴胺释放增加了一倍，但RNF11过表达并未使多巴胺释放减少。RNF11敲低并未显著增加刺激诱导的血清素或章鱼胺释放，表明该作用具有多巴胺特异性。多巴胺清除率也发生了变化，因为RNF11 RNA干扰果蝇的V值较高，而RNF11过表达果蝇的V值低于对照果蝇。RNF11 RNA干扰果蝇中多巴胺转运体（DAT）的mRNA水平升高，证实了DAT的变化。在RNF11 RNA干扰果蝇中，短时间间隔重复刺激时释放维持得更好，表明多巴胺的可循环释放池增加。去甲替林（一种DAT抑制剂）和氟哌噻吨（一种D2拮抗剂）对RNF11 RNA干扰或过表达果蝇的影响与对照果蝇没有差异。因此，RNF11敲低导致多巴胺神经传递的早期变化，这是首次证明RNF11影响多巴胺释放和摄取的研究。在PD患者的人多巴胺能神经元中，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而具有保护作用。
