Endogenous inhibins regulate steroidogenesis in mouse TM3 Leydig cells by altering SMAD2 signalling
Endogenous inhibins regulate steroidogenesis in mouse TM3 Leydig cells by altering SMAD2 signalling
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DOI：
10.1016/j.mce.2016.07.026
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发表时间：
2016-11
影响因子：
4.1
通讯作者：
Yao Wang;Maree Bilandzic;G. Ooi;J. Findlay;K. Stenvers
中科院分区：
文献类型：
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作者：
Yao Wang;Maree Bilandzic;G. Ooi;J. Findlay;K. Stenvers
本研究以青春期前间质细胞系TM3作为未成熟间质细胞的模型，验证了抑制素以自分泌方式作用于间质细胞的假设。RT-PCR检测TM3细胞中finha、Inhba、inhbbin的表达，western blot检测抑制素α亚基的产生。敲低finhaa表达导致间质细胞标记物scyp17a1、Cyp11a1、Nr5a1和insl3的表达显著降低。Western blot结果显示，激活素A、TGFβ1和TGFβ2可激活SMAD2，抑制TM3细胞中finha表达可增强激活素A和tgf β诱导的SMAD2激活。SB431542是一种TGFβ/激活素I型受体的化学抑制剂，阻断配体诱导的SMAD2激活和cyp17a1表达的下调。我们的研究结果表明TGFβs和激活素A通过ALK4/5和SMAD2负向调节TM3细胞中的类固醇基因表达，而内源性抑制素可以对抗这种调节。
This study tested the hypothesis that inhibins act in an autocrine manner on Leydig cells using a pre-pubertal Leydig cell line, TM3, as a model of immature Leydig cells. The expression ofInha,Inhba, andInhbbin TM3 cells was determined by RT-PCR and the production of the inhibin-alpha subunit was confirmed by western blot. Knockdown ofInhaexpression resulted in significant decreases in the expression of Leydig cell markersCyp17a1,Cyp11a1,Nr5a1, andInsl3. Western blot showed that activin A, TGFβ1 and TGFβ2 activated SMAD2, and that knockdown ofInhaexpression in TM3 cells enhanced both activin A- and TGFβ-induced SMAD2 activation. SB431542, a chemical inhibitor of the TGFβ/activin type I receptors, blocked ligand-induced SMAD2 activation and the downregulation ofCyp17a1expression. Our findings demonstrate that TGFβs and activin A negatively regulate steroidogenic gene expression in TM3 cells via ALK4/5 and SMAD2 and endogenous inhibins can counter this regulation.