Bethea Cynthia L, Phu Kenny, Belikova Yelena, Bethea Sarah C
Division of Reproductive Sciences, Oregon National Primate Research Center, Beaverton, OR 97006, United States; Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR 97006, United States; Department of Obstetrics and Gynecology, Oregon Health and Science University, Portland, OR 97201, United States.
Division of Reproductive Sciences, Oregon National Primate Research Center, Beaverton, OR 97006, United States.
J Chem Neuroanat. 2015 Jul-Sep;66-67:19-27. doi: 10.1016/j.jchemneu.2015.04.001. Epub 2015 Apr 20.
We previously showed that tryptophan hydroxylase 2 (TPH2) and serotonin reuptake transporter (SERT) mRNAs are increased by the androgens, testosterone (T) and dihydrotestosterone (DHT) in serotonin neurons of male macaques. In addition, we observed that serotonin in axons of a terminal region were markedly decreased by aromatase inhibition and lack of estradiol (E) from metabolism of T. These observations implicated androgen receptors (AR) and estrogen receptors (ER) in the transduction of steroid hormone actions in serotonin neurons. Due to the longer treatment period employed, the expression of the cognate nuclear receptors was sought. We used single and double immunohistochemistry to quantitate and phenotypically localize AR, ERα and ERβ in the dorsal raphe of male macaques. Male Japanese macaques (Macaca fuscata) were castrated for 5-7 months and then treated for 3 months with [1] placebo, [2] T, [3] DHT (non-aromatizable androgen) plus ATD (steroidal aromatase inhibitor), or [4] Flutamide (FLUT; androgen antagonist) plus ATD (n = 5/group). After single labeling of each receptor, quantitative image analysis was applied and receptor positive neurons were counted. Double-label of raphe neurons for each receptor plus TPH2 determined whether the receptors were localized in serotonin neurons. There were significantly more AR-positive neurons in T- and DHT+ATD-treated groups (p = 0.0014) compared to placebo or FLUT+ATD-treated groups. There was no difference in the number of positive-neurons stained for ERα or ERβ⋅ Double-immunohistochemistry revealed that serotonin neurons did not contain AR. Rather, AR-positive nuclei were found in neighboring cells that are likely neurons. However, approximately 40% of dorsal raphe serotonin neurons contained ERα or ERβ⋅ In conclusion, the stimulatory effect of androgens on TPH2 and SERT mRNA expression is mediated indirectly by neighboring neurons contain AR. The stimulatory effect of E, derived from T metabolism, on serotonin transport is partially mediated directly via nuclear ERs.
我们之前发现，在雄性猕猴的5-羟色胺能神经元中，雄激素睾酮（T）和二氢睾酮（DHT）可使色氨酸羟化酶2（TPH2）和5-羟色胺再摄取转运体（SERT）的信使核糖核酸（mRNA）增加。此外，我们观察到，通过芳香化酶抑制以及T代谢产生的雌二醇（E）缺乏，终末区域轴突中的5-羟色胺显著减少。这些观察结果表明，雄激素受体（AR）和雌激素受体（ER）参与了5-羟色胺能神经元中类固醇激素作用的转导。由于采用了较长的治疗期，因此对相关核受体的表达进行了研究。我们使用单重和双重免疫组织化学方法对雄性猕猴中缝背核中的AR、ERα和ERβ进行定量和表型定位。将雄性日本猕猴（食蟹猴）阉割5-7个月，然后用[1]安慰剂、[2]T、[3]DHT（不可芳香化雄激素）加阿那曲唑（ATD，甾体芳香化酶抑制剂）或[4]氟他胺（FLUT，雄激素拮抗剂）加ATD治疗3个月（每组n = 5）。在对每种受体进行单标记后，进行定量图像分析并计数受体阳性神经元。与安慰剂或FLUT + ATD治疗组相比，T和DHT + ATD治疗组中AR阳性神经元明显更多（p = 0.0014）。ERα或ERβ染色的阳性神经元数量没有差异。双重免疫组织化学显示，5-羟色胺能神经元不含AR。相反，在可能是神经元的相邻细胞中发现了AR阳性核。然而，约40%的中缝背核5-羟色胺能神经元含有ERα或ERβ。总之，雄激素对TPH2和SERT mRNA表达的刺激作用是由含有AR的相邻神经元间接介导的。T代谢产生的E对5-羟色胺转运的刺激作用部分是通过核ER直接介导的。
