Licona Paula, Chimal-Monroy Jesús, Soldevila Gloria
Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Circuito Escolar s/n, México DF-04510.
Dev Dyn. 2006 Apr;235(4):1124-32. doi: 10.1002/dvdy.20707.
Activins are members of the transforming growth factor-beta (TGFbeta) superfamily, which regulate cell differentiation processes. Here we report the first quantitative analysis of the expression of Activin/Inhibin ligands, type I and II receptors, as well as Smad proteins in fetal (E14-E16) and adult thymic subpopulations. Our data showed that Alk4, ActRIIA, ActRIIB, and Smads 2, 3, and 4, are expressed in fetal thymus (E14 > E15 > E16) and in thymocytes from adult mice (mostly in the double negative [DN] subpopulation). Ligand expression analysis showed that betaA, betaB, and alpha subunits were mainly detected in thymic stromal cells. Interestingly, alpha subunits were expressed at much higher levels compared to betaA and betaB subunits, demonstrating for the first time the potential role of Inhibins as important mediators during early T cell development. Our data indicate that Activin/Inhibin signaling could regulate the process of thymus organogenesis and early thymocyte differentiation, as it has been demonstrated for other members of the TGF-beta superfamily.
激活素是转化生长因子-β（TGFβ）超家族的成员，该家族调节细胞分化过程。在此，我们报告了激活素/抑制素配体、I型和II型受体以及Smad蛋白在胎儿（E14 - E16）和成年胸腺亚群中表达的首次定量分析。我们的数据显示，Alk4、ActRIIA、ActRIIB以及Smad 2、3和4在胎儿胸腺（E14 > E15 > E16）和成年小鼠的胸腺细胞中表达（主要在双阴性[DN]亚群中）。配体表达分析表明，βA、βB和α亚基主要在胸腺基质细胞中检测到。有趣的是，与βA和βB亚基相比，α亚基的表达水平要高得多，首次证明了抑制素在早期T细胞发育过程中作为重要介质的潜在作用。我们的数据表明，激活素/抑制素信号传导可能调节胸腺器官发生和早期胸腺细胞分化过程，正如TGF-β超家族的其他成员所证明的那样。
