Expression of the GABAA receptor/Chloride Channel in murine spermatogenic cells
Expression of the GABAA receptor/Chloride Channel in murine spermatogenic cells
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DOI：
10.14670/hh-26.95
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发表时间：
2011-01-01
影响因子：
2
通讯作者：
Otsuki, Yoshinori
中科院分区：
文献类型：
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作者：
Kanbara, Kiyoto;Mori, Yoshiaki;Otsuki, Yoshinori
本实验室前期的研究表明，在精子发生过程中，精子细胞顶体表达GABA和GABA(B)受体亚基。此外，我们先前对谷氨酸脱羧酶(GAD)67-GFP敲入小鼠的研究表明，GFP阳性细胞定位于附睾头上皮细胞。在本研究中，我们用RT-PCR检测了小鼠生精细胞中的GABA(A)亚单位，包括α1、α5、β1-3和伽马3，以及GAD、GAD65和GAD67的两种亚型。免疫印迹分析证实了这些蛋白的表达。免疫组织化学显示，GABA(A)受体的GABA、GAD65和α5、β1和γ3亚单位定位于生精细胞膜上，包括精母细胞和精子细胞。全细胞膜片钳分析表明，GABA在一些大而圆的生精细胞中诱导了一种内向氯电流。我们的发现表明，生精细胞本身有一个GABA产生系统，GABA可能通过离子型GABA(A)受体发挥作用。这些数据表明，GABA能系统可能在男性生殖系统中发挥重要作用。
Previous studies from our laboratory have demonstrated that gamma-aminobutyric acid (GABA) and GABA(B) receptor subunits are expressed within the acrosome of spermatids during spermiogenesis. Furthermore, our previous study with the glutamate decarboxylase (GAD) 67-GFP knock-in mouse demonstrated that GFP-positive cells were localized to the epithelium of the caput of epididymis. In the present study, we detected GABA(A) subunits, including alpha 1, alpha 5, beta 1-3 and gamma 3, and both isoforms of GAD, GAD65 and GAD67, in mouse spermatogenic cells using RT-PCR. The expression of these proteins was subsequently confirmed by western blot analysis. Immunohistochemistry also revealed that GABA, GAD65, and alpha 5, beta 1 and gamma 3 subunits of the GABA(A) receptor were localized in the membrane of spermatogenic cells, including spermatocytes and spermatids. The whole-cell patch-clamp analysis demonstrated that GABA application induced an inward chloride current in some of the large and round spermatogenic cells. Our findings show that spermatogenic cells have a GABA producing system by themselves, and that GABA may function via the ionotropic GABA(A) receptor. This data suggests that the GABAergic system may play important roles in the male reproductive system.