The FOS/AP-1 Regulates Metabolic Changes and Cholesterol Synthesis in Human Periovulatory Granulosa Cells
The FOS/AP-1 Regulates Metabolic Changes and Cholesterol Synthesis in Human Periovulatory Granulosa Cells
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DOI：
10.1210/endocr/bqab127
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发表时间：
2021-06-25
期刊：
影响因子：
4.8
通讯作者：
Jo, Misung
中科院分区：
文献类型：
--
作者：
Choi, Yohan;Jeon, Hayce;Jo, Misung
FOS是激活蛋白-1（AP-1）转录因子的一个亚基，参与多种细胞变化。在人类卵巢中，FOS及其异二聚体结合伴侣JUN、JUNB和JUND的表达在排卵期卵泡中增加。然而，FOS/AP-1的具体作用仍然难以捉摸。本研究利用原代人卵巢颗粒/黄体细胞（hGLC）研究了FOS及其配体表达的调控机制以及FOS的功能。人绒毛膜促性腺激素（hCG）诱导FOS表达的双相增加，在1至3小时和12小时达到峰值。JUN蛋白的水平也通过hCG增加，具有不同的表达模式。免疫共沉淀分析表明，FOS是目前作为异源二聚体与所有JUN蛋白。hCG立即激活蛋白激酶A和p42/44 MAPK信号通路，这些通路的抑制剂消除了hCG诱导的FOS、JUN和JUNB水平的升高。为了鉴定由FOS调节的基因，使用用hCG +/- T-5224（FOS抑制剂）处理的hGLC进行高通量RNA测序。测序数据分析显示，FOS抑制影响许多基因的表达，包括一组参与排卵期过程的基因，如基质重塑，前列腺素合成，糖酵解和胆固醇生物合成。定量PCR分析验证了hCG诱导的T-5224调节的参与这些过程的基因的选择表达。因此，T-5224可抑制hCG诱导的代谢活动和胆固醇水平升高。本研究揭示了FOS/ AP-1复合物在人围排卵期卵泡颗粒细胞/黄体细胞代谢变化和胆固醇生物合成中的潜在下游靶基因和作用。
FOS, a subunit of the activator protein-1 (AP-1) transcription factor, has been implicated in various cellular changes. In the human ovary, the expression of FOS and its heterodimeric binding partners JUN, JUNB, and JUND increases in periovulatory follicles. However, the specific role of the FOS/AP-1 remains elusive. The present study determined the regulatory mechanisms driving the expression of FOS and its partners and functions of FOS using primary human granulosa/lutein cells (hGLCs). Human chorionic gonadotropin (hCG) induced a biphasic increase in the expression of FOS, peaking at 1 to 3 hours and 12 hours. The levels of JUN proteins were also increased by hCG, with varying expression patterns. Coimmunoprecipitation analyses revealed that FOS is present as heterodimers with all JUN proteins. hCG immediately activated protein kinase A and p42/44MAPK signaling pathways, and inhibitors for these pathways abolished hCG-induced increases in the levels of FOS, JUN, and JUNB. To identify the genes regulated by FOS, high-throughput RNA sequencing was performed using hGLC treated with hCG +/- T-5224 (FOS inhibitor). Sequencing data analysis revealed that FOS inhibition affects the expression of numerous genes, including a cluster of genes involved in the periovulatory process such as matrix remodeling, prostaglandin synthesis, glycolysis, and cholesterol biosynthesis. Quantitative PCR analysis verified hCG-induced, T-5224-regulated expression of a selection of genes involved in these processes. Consistently, hCG-induced increases in metabolic activities and cholesterol levels were suppressed by T-5224. This study unveiled potential downstream target genes of and a role for the FOS/ AP-1 complex in metabolic changes and cholesterol biosynthesis in granulosa/lutein cells of human periovulatory follicles.