Regulation by gonadal steroids of the mRNA encoding for a type I receptor for TGF-β in the female rat hypothalamus
Regulation by gonadal steroids of the mRNA encoding for a type I receptor for TGF-β in the female rat hypothalamus
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DOI：
10.1159/000063678
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发表时间：
2002-07-01
影响因子：
4.1
通讯作者：
Mitchell, V
中科院分区：
文献类型：
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作者：
Bouret, S;Prevot, V;Mitchell, V
我们最近的研究表明，编码转化生长因子β和激活素的I型受体B1的mRNA在下丘脑区域表达，涉及促性腺激素释放激素调节，特别是在雌激素接受区。在本研究中，我们研究了卵巢类固醇是否可以调节下丘脑B1 mRNA的表达。比较去卵巢（OVX）、OVX +雌二醇处理和OVX +雌二醇+孕酮处理的雌性大鼠131 mRNA的相对表达水平，我们发现雌激素显著（p < 0.05）下调了腹前侧脑室周围核（12.5%）、内侧视前核（27.5%）和弓形核（29.5%）的B1 mRNA水平。相比之下，在正中视前核中未观察到性腺激素的作用。接下来，我们研究了表达B1 mRNA的细胞是否可能是雌激素作用的直接靶点。通过原位杂交结合免疫组织化学标记，我们发现许多b1 - mrna表达细胞在前腹侧脑室周围核、内侧视前核和弓形核中也表现出雌激素受体α免疫反应。综上所述，这些结果表明雌激素可能直接调节下丘脑B1 mRNA的表达，并支持转化生长因子β在下丘脑控制促性腺激素释放激素功能中发挥重要作用的观点。版权所有(C) 2002 S. Karger AG，巴塞尔。
We have recently shown that the mRNA encoding for a type I receptor for transforming growth factor beta and activin - named B1 - is expressed in hypothalamic areas implicated in gonadotropin-releasing hormone regulation, particularly in estrogen-receptive regions. In the present study, we examined whether ovarian steroids may regulate expression of B1 mRNA in the hypothalamus. Comparing relative levels of 131 mRNA expression in ovariectomized (OVX), OVX + estradiol-treated, and OVX + estradiol + progesterone-treated female rats, we observed that estrogen significantly (p < 0.05) downregulated B1 mRNA levels in the anteroventral periventricular nucleus (by 12.5%), medial preoptic nucleus (by 27.5%), and arcuate nucleus (by 29.5%). In contrast, no effects of gonadal steroids were observed in the median preoptic nucleus. We next examined whether cells expressing B1 mRNA may be direct targets for the action of estrogen. Using an in situ hybridization coupled to immunohistochemical labeling, we found that many B1-mRNA-expressing cells also exhibited estrogen receptor alpha immunoreactvity in anteroventral periventricular nucleus, medial preoptic nucleus, and arcuate nucleus. Taken together, these results reveal that estrogen may directly modulate expression of B1 mRNA in the hypothalamus and support the idea that transforming growth factors beta play an important role in the hypothalamic control of gonadotropin-releasing hormone function. Copyright (C) 2002 S. Karger AG, Basel.