Increased expression of miR-325-3p by urocortin 2 and its involvement in stress-induced suppression of LH secretion in rat pituitary
Increased expression of miR-325-3p by urocortin 2 and its involvement in stress-induced suppression of LH secretion in rat pituitary
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DOI：
10.1152/ajpendo.00616.2011
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发表时间：
2012-04-01
影响因子：
5.1
通讯作者：
Shibasaki, Tamotsu
中科院分区：
文献类型：
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作者：
Nemoto, Takahiro;Mano, Asuka;Shibasaki, Tamotsu
Nemoto T，Mano A，Shibasaki T. Urocortin 2增加miR-325- 3 p表达及其参与大鼠垂体应激诱导的LH分泌抑制Am J Physiol Endocrinol Metab 302：E781-E787，2012.首次发表于2012年1月17日; doi：10.1152/ajpendo.00616.2011。尿皮质素2（Ucn 2）是促肾上腺皮质激素释放因子（CRF）肽家族的成员，其结合CRF 2型受体。我们曾报道Ucn 2在大鼠垂体前阿黑皮素细胞中的表达及其对LH分泌的抑制作用。我们还证明Ucn 2参与了固定诱导的LH分泌抑制的机制;细节尚不清楚。在这里，我们发现Ucn 2增加了miR-325- 3 p的表达，miR-325 - 3 p是单层培养的大鼠垂体前叶细胞中与LH β亚基3 '-非翻译区（3'-UTR）结合的三种预测序列的microRNA之一，并且miR-325- 3 p在垂体前叶的LH细胞中表达。固定还增加了垂体前叶中miR-325- 3 p的表达，并且其增加被抗Ucn 2 IgG预处理阻断。miR-325- 3 p在培养的垂体细胞中的过表达显著抑制细胞内内容物和LH分泌，而miR-325- 3 p敲低阻断Ucn 2诱导的细胞内内容物和LH分泌的抑制。miR-325- 3 p与LH β亚基3 '-UTR融合的荧光素酶载体的共表达显著抑制了荧光素酶活性。这些结果表明，miR-325- 3 p参与固定诱导的LH翻译和分泌抑制，Ucn 2在miR-325- 3 p表达增加中起作用。
Nemoto T, Mano A, Shibasaki T. Increased expression of miR-325-3p by urocortin 2 and its involvement in stress-induced suppression of LH secretion in rat pituitary. Am J Physiol Endocrinol Metab 302: E781-E787, 2012. First published January 17, 2012; doi: 10.1152/ajpendo.00616.2011.-Urocortin 2 (Ucn2) is a member of the corticotropin releasing factor (CRF) peptide family, which binds to CRF type 2 receptor. We previously reported on expression of Ucn2 in proopiomelanocortin cells of rat pituitary and its inhibitory action on LH secretion. We also demonstrated that Ucn2 is involved in the mechanism underlying immobilization-induced suppression of LH secretion; the details remain unclear. Here, we found that Ucn2 increased the expression of miR-325-3p, one of three microRNAs with predicted sequence for binding to LH beta-subunit 3'-untranslated region (3'-UTR) in monolayer cultured rat anterior pituitary cells, and that miR-325-3p was expressed in LH cells of the anterior pituitary. Immobilization also increased miR-325-3p expression in the anterior pituitary, and its increase was blocked by pretreatment with anti-Ucn2 IgG. Overexpression of miR-325-3p in cultured pituitary cells significantly suppressed intracellular contents and secretion of LH, while miR-325-3p knockdown blocked Ucn2-induced suppression of intracellular contents and secretion of LH. Coexpression of miR-325-3p with LH beta-subunit 3'-UTR-fused luciferase vector significantly suppressed luciferase activity compared with that of mock transfectants. These results suggest that miR-325-3p is involved in immobilization-induced suppression of LH translation and secretion and that Ucn2 plays a role in the increase in miR-325-3p expression.