College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
J Zhejiang Univ Sci B. 2010 Sep;11(9):719-27. doi: 10.1631/jzus.B1000079.
Bone morphogenetic proteins (BMPs) play a critical role in the growth and steroidogenesis of granulosa cells (GCs). BMP signals act through membrane-bound heteromeric serine/threonine kinase receptors. Upon ligand binding, BMPs activate intracellular Smad proteins and regulate growth and apoptosis in various cell types. The objective of this study was to demonstrate the effects of BMP/Smad signal on growth and steroidogenesis of porcine GCs. A strategy of RNA interference (RNAi)-mediated 'gene silencing' of Smad4, a core molecule mediating the intracellular BMP/Smad signal transduction pathways, was used to interrupt endogenous BMP/Smad signaling. Results indicate that Smad4-small interfering RNA (siRNA) caused specific inhibition of Smad4 mRNA and protein expression after transfection. Interrupted endogenous BMP/Smad signaling significantly inhibited growth, and induced apoptosis of porcine GCs, while decreasing estradiol production. In addition, interrupted BMP/Smad signaling significantly (P<0.05) changed the expression of Cyclin D2, CDK4, Bcl-2, and Cyp19a1. These findings provide new insights into how BMP/Smad signaling regulates the growth and steroidogenesis of porcine GCs.
骨形态发生蛋白（BMPs）在颗粒细胞（GCs）的生长和类固醇生成中起着关键作用。BMP 信号通过膜结合的异源丝氨酸/苏氨酸激酶受体发挥作用。配体结合后，BMP 激活细胞内 Smad 蛋白，调节各种细胞类型的生长和凋亡。本研究旨在证明 BMP/Smad 信号对猪 GCs 生长和类固醇生成的影响。采用 RNA 干扰（RNAi）介导的 Smad4“基因沉默”策略，Smad4 是一种介导细胞内 BMP/Smad 信号转导途径的核心分子，用于中断内源性 BMP/Smad 信号。结果表明，转染后 Smad4 小干扰 RNA（siRNA）可特异性抑制 Smad4 mRNA 和蛋白表达。中断内源性 BMP/Smad 信号显著抑制猪 GCs 的生长，并诱导其凋亡，同时减少雌二醇的产生。此外，中断 BMP/Smad 信号显著改变了 Cyclin D2、CDK4、Bcl-2 和 Cyp19a1 的表达。这些发现为 BMP/Smad 信号如何调节猪 GCs 的生长和类固醇生成提供了新的见解。
