Jiangsu Livestock Embryo Engineering Laboratory, Nanjing Agricultural University, Nanjing 210095, China.
Int J Mol Sci. 2023 Jun 26;24(13):10656. doi: 10.3390/ijms241310656.
Pituitary gonadotropins perform essential functions in mammalian reproduction by stimulating gametogenesis and steroidogenesis in the ovaries and testicles. EZH2 is a histone methyltransferase that inhibits proliferation and aggravates apoptosis in stem cells subjected to pathological stimuli. However, the expression and molecular mechanisms of EZH2 in pituitary cells in vitro have not been extensively studied. In this study, the relative abundances of EZH2 mRNA ( < 0.01) and protein ( < 0.05) expression were larger in the pituitary cells of Hu sheep with relatively greater fecundity (GF) compared to those with lesser fecundity (LF). Loss-of-function examinations demonstrated that gene knockdown led to an earlier induction of apoptosis in sheep pituitary cells (PCs). The relative abundance of , , and was increased ( < 0.01), while 's abundance was less decreased ( < 0.01) in PCs where there was gene knockdown. Additionally, cell proliferation ( < 0.01) and viability ( < 0.01) were decreased in EZH2-knockdown sheep PCs, and the cell cycle was blocked compared to a negative control (NC). Notably, gene knockdown led to reduced abundances of gonadotropin subunit gene transcripts (FSHβ, < 0.05) and reduced FSH release ( < 0.01) from PCs. gene knockdown led to reduced phosphorylation of AKT, ERK, and mTOR ( < 0.01). The results suggest that EZH2 regulates pituitary cell proliferation, apoptosis, and FSH secretion through modulation of the AKT/ERK signaling pathway, providing a foundation for further study of pituitary cell functions.
垂体促性腺激素通过刺激卵巢和睾丸中的配子发生和类固醇生成，在哺乳动物生殖中发挥重要功能。EZH2 是一种组蛋白甲基转移酶，可抑制增殖并加重干细胞受到病理刺激后的凋亡。然而，EZH2 在体外垂体细胞中的表达及其分子机制尚未得到广泛研究。在这项研究中，与繁殖力较低的 LF 羊相比，繁殖力较强的 GF 羊的垂体细胞中 EZH2 mRNA（<0.01）和蛋白（<0.05）的相对丰度更大。功能丧失研究表明，基因敲低导致绵羊垂体细胞（PCs）更早地诱导凋亡。的相对丰度增加（<0.01），而 的丰度减少较少（<0.01），在基因敲低的 PCs 中。此外，EZH2 敲低的绵羊 PCs 中的细胞增殖（<0.01）和活力（<0.01）降低，与阴性对照（NC）相比，细胞周期被阻断。值得注意的是，基因敲低导致促性腺激素亚基基因转录物（FSHβ，<0.05）丰度降低和 PCs 中 FSH 释放减少（<0.01）。基因敲低导致 AKT、ERK 和 mTOR 的磷酸化减少（<0.01）。结果表明，EZH2 通过调节 AKT/ERK 信号通路调节垂体细胞增殖、凋亡和 FSH 分泌，为进一步研究垂体细胞功能提供了基础。
