Department of Anatomy and Neurobiology, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan.
Brain Res. 2010 Jan 15;1310:17-28. doi: 10.1016/j.brainres.2009.11.004. Epub 2009 Nov 11.
Estrogens were originally identified as the primary sex steroid hormones in females and regulators of reproductive function and sexual behavior, but it has long been suggested that estrogens also have local effects on the somatosensory system at the spinal cord level. It is well known that the effects of estrogens are mediated by nuclear estrogen receptors (ERs) through genomic action, but recently a membrane-bound G protein-coupled receptor, GPR30, was identified as a non-genomic estrogen receptor. In this study we investigated the presence and localization of GPR30 in the rat spinal cord and dorsal root ganglion (DRG) in comparison with ERalpha. Using immunohistochemistry and in situ hybridization, we showed the expression of GPR30 in DRG neurons in male and female rats at mRNA and protein levels without specific sexual difference. A dense accumulation of GPR30 immunoreactivity was observed in the outer layer of the spinal dorsal horn, and selective spinal dorsal rhizotomy revealed that GPR30 was transported from the DRG to terminals located in the spinal dorsal horn. GPR30 expression was downregulated in DRG neurons of ovariectomized female rats. The spinal somatosensory system might be modulated by estradiol via putative membrane ER, GPR30-mediated mechanism.
雌激素最初被确定为女性的主要性激素，调节生殖功能和性行为，但长期以来一直认为雌激素对脊髓水平的躯体感觉系统也有局部作用。众所周知，雌激素的作用是通过核雌激素受体 (ER) 通过基因组作用介导的，但最近发现一种膜结合的 G 蛋白偶联受体 GPR30 是一种非基因组雌激素受体。在这项研究中，我们研究了 GPR30 在雄性和雌性大鼠脊髓和背根神经节 (DRG) 中的存在和定位，并与 ERalpha 进行了比较。通过免疫组织化学和原位杂交，我们在雄性和雌性大鼠的 DRG 神经元中显示了 GPR30 在 mRNA 和蛋白质水平上的表达，没有特定的性别差异。在外层的脊髓背角中观察到 GPR30 免疫反应的密集积累，选择性的脊髓背根切断术显示 GPR30 从 DRG 被运送到位于脊髓背角的末端。去卵巢雌性大鼠的 DRG 神经元中 GPR30 的表达下调。雌激素可能通过潜在的膜 ER、GPR30 介导的机制调节脊髓躯体感觉系统。
