Variable proopiomelanocortin expression in tanycytes of the adult rat hypothalamus and pituitary stalk.
Variable proopiomelanocortin expression in tanycytes of the adult rat hypothalamus and pituitary stalk.
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DOI：
10.1002/cne.24090
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发表时间：
2017-02-15
影响因子：
2.5
通讯作者：
Lechan, Ronald M.
中科院分区：
文献类型：
--
作者：
Wittmann, Gabor;Farkas, Erzsebet;Szilvasy-Szabo, Anett;Gereben, Balazs;Fekete, Csaba;Lechan, Ronald M.
关键词：
人们普遍认为，阿片黑皮质素原（POMC）仅由成年啮齿动物大脑中的神经元表达。然而，大多数研究人员不知道的是，对大鼠进行的 Pomc 原位杂交研究显示，下丘脑第三脑室的腹壁有特异性标记，该标记是由特殊的室管膜细胞（称为单细胞）形成的。在这里，我们使用原位杂交和免疫组织化学技术详细描述了这种非神经元 POMC 表达，并报告了两个独特的特征。首先，非神经元细胞中 POMC mRNA 和前体蛋白的表达在表达程度和丰度方面存在很大程度的差异。在低水平表达的大脑中，POMC mRNA和蛋白质主要局限于漏斗柄/尾正中隆起内的一群单胞，此处称为γ单胞，以及紧密定位的β和α2单胞的子集。在高水平表达的大脑中，在绝大多数α2、β和γ单细胞中观察到POMC mRNA和蛋白质。在成年男性和女性中都观察到了这种变异性。在 41 只 8 至 15 周龄的大鼠中，17 只大鼠的单细胞 POMC 表达水平较低，9 只为中度，15 只为高水平。其次，与其他已知的 POMC 表达细胞不同，单细胞很少含有可检测水平的促肾上腺皮质激素或 α-黑素细胞刺激激素。结果表明，要么是一种动态时空模式，即每个大脑中单细胞中的低和高 POMC 合成定期发生，要么是可能在整个成年期持续存在的显着个体间差异。未来的研究需要检验这些可能性并阐明 POMC 在单细胞中的生理重要性。
It is generally believed that proopiomelanocortin (POMC) is expressed exclusively by neurons in the adult rodent brain. Unbeknownst to most researchers, however, Pomc in situ hybridization studies in the rat show specific labeling in the ventral wall of the hypothalamic third ventricle, which is formed by specialized ependymal cells, called tanycytes. Here we characterized this non-neuronal POMC expression in detail using in situ hybridization and immunohistochemical techniques, and report two unique characteristics. First, POMC mRNA and precursor protein expression in non-neuronal cells varies to a great degree as to the extent and abundance of expression. In brains with low-level expression, POMC mRNA and protein was largely confined to a population of tanycytes within the infundibular stalk /caudal median eminence, named here as gamma tanycytes, and a subset of closely located β and α2 tanycytes. In brains with high-level expression, POMC mRNA and protein was observed in the vast majority of α2, β and γ tanycytes. This variability was observed in both adult males and females; of 41 rats between 8 to 15 weeks of age, 17 had low-, 9 intermediate-, and 15 high-level POMC expression in tanycytes. Second, unlike other known POMC-expressing cells, tanycytes rarely contained detectable levels of adrenocorticotropin or α-melanocyte-stimulating hormone. The results indicate either a dynamic spatio-temporal pattern where low and high POMC syntheses in tanycytes occur periodically in each brain, or marked interindividual differences that may persist throughout adulthood. Future studies are required to examine these possibilities and elucidate the physiologic importance of POMC in tanycytes.
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影响因子：
3.5
作者：
Borges, B. C.;Antunes-Rodrigues, J.;Elias, L. L. K.
通讯作者：
Elias, L. L. K.
影响因子：
7.7
作者：
Baskin, DG;Breininger, JF;Schwartz, MW
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Schwartz, MW
影响因子：
4.8
作者：
Bouret, S;Prevot, V;Mitchell, V
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Mitchell, V
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Beck, Bernard;Richy, Sebastien;Mercer, Julian G.
通讯作者：
Mercer, Julian G.
影响因子：
4.8
作者：
Bagnasco, M;Dube, MG;Kalra, SP
通讯作者：
Kalra, SP