Changes in Histone Modification and DNA Methylation of the StAR and Cyp19a1 Promoter Regions in Granulosa Cells Undergoing Luteinization during Ovulation In Rats
Changes in Histone Modification and DNA Methylation of the StAR and Cyp19a1 Promoter Regions in Granulosa Cells Undergoing Luteinization during Ovulation In Rats
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DOI：
10.1210/en.2012-1610
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发表时间：
2013-01-01
期刊：
影响因子：
4.8
通讯作者：
Sugino, Norihiro
中科院分区：
文献类型：
--
作者：
Lee, Lifa;Asada, Hiromi;Sugino, Norihiro
排卵性LH峰诱导排卵期间经历黄体化的颗粒细胞（GC）中类固醇生成急性调节（星星）蛋白的快速上调和芳香化酶（Cyp 19 a1）的快速下调。本研究在体内研究了包括组蛋白修饰在内的表观遗传机制是否参与了星星和Cyp 19 a1基因表达的快速变化。在注射人绒毛膜促性腺激素（CG）之前（0 h）和之后（h），从接受马绒毛膜促性腺激素（CG）处理的大鼠中获得GC。星星mRNA水平在hCG注射后迅速升高，4 h达高峰，此后一直高于0 h，直至12 h。注射hCG后Cyp 19 a1 mRNA水平逐渐下降，12 h降至最低。染色质免疫沉淀分析显示，hCG注射后星星启动子中组蛋白-H4乙酰化（Ac-H4）和组蛋白-H3赖氨酸-4（H3 K4 me 3）的三甲基化水平增加，而H3 K9 me 3和H3 K27 me 3减少。另一方面，注射hCG后，Cyp 19 a1启动子中Ac-H3和Ac-H4以及H3 K4 me 3的水平降低，H3 K27 me 3的水平升高。染色质凝聚，这是使用脱氧核糖核酸酶I分析，减少在星星启动子和增加后，hCG注射Cyp 19 a1启动子。染色质免疫沉淀试验也表明，CAATT/增强子结合蛋白β的星星启动子的结合活性增加，磷酸化cAMP反应元件结合蛋白的Cyp 19 a1启动子的结合活性降低后，hCG注射。这些结果提供了体内证据表明，组蛋白修饰参与的星星和Cyp 19 a1基因表达的快速变化，通过改变染色质结构的启动子在GC经历黄体化排卵过程中。（内分泌学154：458-470，2013）
The ovulatory LH surge induces rapid up-regulation of steroidogenic acute regulatory (StAR) protein and rapid down-regulation of aromatase (Cyp19a1) in granulosa cells (GCs) undergoing luteinization during ovulation. This study investigated in vivo whether epigenetic mechanisms including histone modifications are involved in the rapid changes of StAR and Cyp19a1 gene expression. GCs were obtained from rats treated with equine chorionic gonadotropin (CG) before (0 h) and after human (h) CG injection. StAR mRNA levels rapidly increased after hCG injection, reached a peak at 4h, and then remained higher compared with 0h until 12 h. Cyp19a1 mRNA levels gradually decreased after hCG injection and reached their lowest level at 12 h. A chromatin immunoprecipitation assay revealed that levels of histone-H4 acetylation (Ac-H4) and trimethylation of histone-H3 lysine-4 (H3K4me3) increased whereas H3K9me3 and H3K27me3 decreased in the StAR promoter after hCG injection. On the other hand, the levels of Ac-H3 and -H4 and H3K4me3 decreased, and H3K27me3 increased in the Cyp19a1 promoter after hCG injection. Chromatin condensation, which was analyzed using deoxyribonuclease I, decreased in the StAR promoter and increased in the Cyp19a1 promoter after hCG injection. A chromatin immunoprecipitation assay also showed that binding activities of CAATT/enhancer-binding protein beta to the StAR promoter increased and binding activities of phosphorylated-cAMP response element binding protein to the Cyp19a1 promoter decreased after hCG injection. These results provide in vivo evidence that histone modifications are involved in the rapid changes of StAR and Cyp19a1 gene expression by altering chromatin structure of the promoters in GCs undergoing luteinization during ovulation. (Endocrinology 154: 458-470, 2013)