Luteinizing hormone-induced RUNX1 regulates the expression of genes in granulosa cells of rat periovulatory follicles
Luteinizing hormone-induced RUNX1 regulates the expression of genes in granulosa cells of rat periovulatory follicles
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DOI：
10.1210/me.2005-0512
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发表时间：
2006-09-01
影响因子：
--
通讯作者：
Curry, Thomas E., Jr.
中科院分区：
文献类型：
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作者：
Jo, Misung;Curry, Thomas E., Jr.
LH峰诱导特异性转录因子，调节排卵期卵泡中无数基因的表达，从而引起排卵和黄体化。本研究确定了1）核转录因子RUNX 1的定位，2）Runx 1 mRNA表达的调控，3）其在大鼠卵巢中的潜在功能。通过原位杂交、免疫组织化学和Western印迹分析，在促性腺激素处理的未成熟大鼠中注射人绒毛膜促性腺激素（hCG）后以及在周期动物中LH峰后，在排卵前卵泡中检测到RUNX 1的mRNA和蛋白的上调。用大鼠排卵前卵巢颗粒细胞在体外研究Runx 1 mRNA表达的调节。用hCG、毛喉素或佛波醇12肉豆蔻酸酯13-乙酸酯刺激Runx 1 mRNA表达。hCG的作用被蛋白激酶A、MAPK激酶或p38激酶的抑制剂降低，表明Runx 1的表达受LH启动的这些信号介质的激活的调节。此外，hCG诱导的Runx 1 mRNA的表达被孕酮受体拮抗剂和表皮生长因子受体酪氨酸激酶抑制剂抑制，而双调蛋白刺激Runx 1 mRNA的表达，表明表达是由孕酮受体和表皮生长因子受体的激活介导的。最后，小干扰RNA敲低Runx 1 mRNA降低孕酮分泌，并降低Cyp 11 a1，Hapln 1，Mt 1a和Rgc 32的mRNA水平。排卵期卵泡中Runx 1的经尿道调节的表达、其参与孕酮的产生以及排卵前基因表达的调节表明RUNX 1在排卵期过程中的重要作用。
The LH surge induces specific transcription factors that regulate the expression of a myriad of genes in periovulatory follicles to bring about ovulation and luteinization. The present study determined 1) the localization of RUNX1, a nuclear transcription factor, 2) regulation of Runx1 mRNA expression, and 3) its potential function in rat ovaries. Up-regulation of mRNA and protein for RUNX1 is detected in preovulatory follicles after human chorionic gonadotropin ( hCG) injection in gonadotropin-treated immature rats as well as after the LH surge in cycling animals by in situ hybridization and immunohistochemical and Western blot analyses. The regulation of Runx1 mRNA expression was investigated in vitro using granulosa cells from rat preovulatory ovaries. Treatments with hCG, forskolin, or phorbol 12 myristate 13-acetate stimulated Runx1 mRNA expression. The effects of hCG were reduced by inhibitors of protein kinase A, MAPK kinase, or p38 kinase, indicating that Runx1 expression is regulated by the LH-initiated activation of these signaling mediators. In addition, hCG-induced Runx1 mRNA expression was inhibited by a progesterone receptor antagonist and an epidermal growth factor receptor tyrosine kinase inhibitor, whereas amphiregulin stimulated Runx1 mRNA expression, demonstrating that the expression is mediated by the activation of the progesterone receptor and epidermal growth factor receptor. Finally, knockdown of Runx1 mRNA by small interfering RNA decreased progesterone secretion and reduced levels of mRNA for Cyp11a1, Hapln1, Mt1a, and Rgc32. The hormonally regulated expression of Runx1 in periovulatory follicles, its involvement in progesterone production, and regulation of preovulatory gene expression suggest important roles of RUNX1 in the periovulatory process.