Mnie-Filali Ouissame, Lau Thorsten, Matthaeus Friederike, Abrial Erika, Delcourte Sarah, El Mansari Mostafa, Pershon Alan, Schloss Patrick, Sánchez Connie, Haddjeri Nasser
Univ Lyon, Université Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France.
Department of Integrative Neurophysiology, CNCR, Vrije Universiteit, Amsterdam, The Netherlands.
CNS Neurosci Ther. 2016 Aug;22(8):691-9. doi: 10.1111/cns.12562. Epub 2016 May 12.
Studies using S- and R-enantiomers of the SSRI citalopram have shown that R-citalopram exerts an antagonistic effect on the efficacy of the antidepressant S-citalopram (escitalopram) through an interaction at an allosteric modulator site on the serotonin transporter (SERT). Here, we show that protein kinase signaling systems are involved in the allosteric modulation of the SERT in vivo and in vitro.
We assessed the effects of nonspecific protein kinase inhibitor staurosporine in the action of escitalopram and/or R-citalopram using electrophysiological and behavioral assays in rats and cell surface SERT expression measures in serotoninergic cells.
Acute administration of R-citalopram counteracted the escitalopram-induced suppression of the serotonin (5-HT) neuronal firing activity and increase of the head twitches number following L-5-hydroxytryptophan injection. Importantly, these counteracting effects of R-citalopram were abolished by prior systemic administration of staurosporine. Interestingly, the preventing effect of staurosporine on 5-HT neuronal firing activity was abolished by direct activation of protein kinase C with phorbol 12-myristate 13-acetate. Finally, in vitro, quantification of the amount of cell surface-expressed SERT molecules revealed that R-citalopram prevented escitalopram-induced SERT internalization that was completely altered by staurosporine.
Taken together, these results highlight for the first time an involvement of protein kinases in the allosteric modulation of SERT function.
使用选择性5-羟色胺再摄取抑制剂（SSRI）西酞普兰的S-和R-对映体进行的研究表明，R-西酞普兰通过与血清素转运蛋白（SERT）上的变构调节剂位点相互作用，对抗抑郁药S-西酞普兰（艾司西酞普兰）的疗效产生拮抗作用。在此，我们表明蛋白激酶信号系统在体内和体外参与了SERT的变构调节。
我们使用大鼠的电生理和行为分析以及血清素能细胞中细胞表面SERT表达测量，评估了非特异性蛋白激酶抑制剂星形孢菌素在艾司西酞普兰和/或R-西酞普兰作用中的影响。
急性给予R-西酞普兰可抵消艾司西酞普兰诱导的血清素（5-HT）神经元放电活动的抑制以及注射L-5-羟色氨酸后头部抽搐次数的增加。重要的是，R-西酞普兰的这些拮抗作用被预先全身给予星形孢菌素所消除。有趣的是，星形孢菌素对5-HT神经元放电活动的预防作用被佛波酯12-肉豆蔻酸酯13-乙酸酯直接激活蛋白激酶C所消除。最后，在体外，对细胞表面表达的SERT分子数量的定量显示，R-西酞普兰可防止艾司西酞普兰诱导的SERT内化，而星形孢菌素可完全改变这种内化。
综上所述，这些结果首次突出了蛋白激酶参与SERT功能的变构调节。
