Baddela Vijay Simha, Michaelis Marten, Tao Xuelian, Koczan Dirk, Brenmoehl Julia, Vanselow Jens
Reproduction. 2025 Jan 21;169(2). doi: 10.1530/REP-24-0317. Print 2025 Feb 1.
PI3K-AKT signaling activates steroidogenesis by inducing estradiol and progesterone production, while MEK-ERK1/2 signaling regulates steroidogenesis by inhibiting estradiol and inducing progesterone production in granulosa cells (GCs). Both pathways are essential for glycolytic and mitochondrial metabolism in these cells.
The PI3K-AKT and MEK-ERK1/2 signaling pathways are integral to fundamental cellular processes, such as proliferation, viability and differentiation. In GCs, these pathways are activated by follicle-stimulating hormone (FSH) and IGF1 through respective receptors. We investigated the comparative transcriptome changes induced by the AKT and ERK (ERK1/2) pathways using corresponding inhibitors in GCs. GCs isolated from antral follicles showed positive signals for phospho-AKT and phospho-ERK proteins. Treatment of cultured GCs with FSH and IGF1 induced phospho-AKT and phospho-ERK levels. Transcriptome analysis revealed 1436 genes regulated by AKT and 654 genes regulated by the ERK pathway. Among these, 94 genes were commonly downregulated and 11 genes were commonly upregulated in both datasets, while 110 genes were oppositely regulated. Bioinformatics analysis revealed that the inhibition of the PI3K-AKT and MEK-ERK pathways downregulates key reproductive processes and upstream molecules. Notably, AKT inhibition affected FSH, ESRRG and HIF1 pathways, while ERK inhibition impacted CG, FOS, TGFβ, EGR1 and LH pathways. Transcriptome data showed that genes related to estradiol production were inhibited by ERK and induced by the AKT pathway. This was verified by radioimmunoassays, and mRNA and protein analysis of CYP19A1 and STAR genes. In addition, transcriptome data suggested the downregulation of glucose metabolism in GCs. Using validation experiments, we confirm that both pathways are essential for glucose uptake, lactate production and mitochondrial activity in GCs. These data provide a resource for informing future research for analyzing various novel candidate genes regulated by the AKT and ERK pathways in GCs and other cell types.
PI3K-AKT信号通路通过诱导雌二醇和孕酮生成来激活类固醇生成，而MEK-ERK1/2信号通路则通过抑制颗粒细胞（GCs）中的雌二醇并诱导孕酮生成来调节类固醇生成。这两条通路对于这些细胞中的糖酵解和线粒体代谢至关重要。
PI3K-AKT和MEK-ERK1/2信号通路是细胞增殖、存活和分化等基本细胞过程所必需的。在颗粒细胞中，这些通路分别通过各自的受体被促卵泡激素（FSH）和胰岛素样生长因子1（IGF1）激活。我们使用相应的抑制剂研究了AKT和ERK（ERK1/2）通路在颗粒细胞中诱导的比较转录组变化。从窦状卵泡分离的颗粒细胞显示出磷酸化AKT和磷酸化ERK蛋白的阳性信号。用FSH和IGF1处理培养的颗粒细胞可诱导磷酸化AKT和磷酸化ERK水平。转录组分析揭示了1436个受AKT调控的基因和654个受ERK通路调控的基因。其中，94个基因在两个数据集中均被共同下调，11个基因被共同上调，而110个基因受到相反的调控。生物信息学分析表明，PI3K-AKT和MEK-ERK通路的抑制下调了关键的生殖过程和上游分子。值得注意的是，AKT抑制影响FSH、ESRRG和HIF1通路，而ERK抑制影响CG、FOS、TGFβ、EGR1和LH通路。转录组数据显示，与雌二醇生成相关的基因被ERK抑制并被AKT通路诱导。这通过放射免疫测定以及CYP19A1和STAR基因的mRNA和蛋白质分析得到了验证。此外，转录组数据表明颗粒细胞中葡萄糖代谢下调。通过验证实验，我们证实这两条通路对于颗粒细胞中的葡萄糖摄取、乳酸生成和线粒体活性都是必不可少的。这些数据为未来分析颗粒细胞和其他细胞类型中受AKT和ERK通路调控的各种新型候选基因的研究提供了资源。
