Divisione di Anatomia Patologica, Dipartimento di Citomorfologia, University of Cagliari, Cagliari, Italy.
PLoS One. 2010 Feb 9;5(2):e9111. doi: 10.1371/journal.pone.0009111.
Thymosin beta 4 (Tbeta(4)) is a member of beta-thymosins, a family of peptides that play essential roles in many cellular functions. A recent study from our group suggested a role for Tbeta(4) in the development of human salivary glands. The aim of this study was to analyze the expression of Tbeta(4) in the human gut during development, and in the adult.
METHODOLOGY/PRINCIPAL FINDINGS: Immunolocalization of Tbeta(4) was studied in autoptic samples of tongue, oesophagus, stomach, ileum, colon, liver and pancreas obtained from two human foetuses and two adults. Tbeta(4) appeared unevenly distributed, with marked differences between foetuses and adults. In the stomach, superficial epithelium was positive in foetuses and negative in adults. Ileal enterocytes were strongly positive in the adult and weakly positive in the foetuses. An increase in reactivity for Tbeta(4) was observed in superficial colon epithelium of adults as compared with the foetuses. Striking differences were found between foetal and adult liver: the former showed a very low reactivity for Tbeta(4) while in the adult we observed a strong reactivity in the vast majority of the hepatocytes. A peculiar pattern was found in the pancreas, with the strongest reactivity observed in foetal and adult islet cells.
Our data show a strong expression of Tbeta(4) in the human gut and in endocrine pancreas during development. The observed differential expression of Tbeta(4) suggests specific roles of the peptide in the gut of foetuses and adults. The observed heterogeneity of Tbeta(4) expression in the foetal life, ranging from a very rare detection in liver cells up to a diffuse reactivity in endocrine pancreas, should be taken into account when the role of Tbeta(4) in the development of human embryo is assessed. Future studies are needed to shed light on the link between Tbeta(4) and organogenesis.
胸腺素β4（Tβ4）是β-胸腺素家族的一员，该家族的肽在许多细胞功能中起着至关重要的作用。我们小组的一项最新研究表明，Tβ4 在人唾液腺发育中起作用。本研究旨在分析 Tβ4 在人肠道发育过程中的表达，以及在成人中的表达。
方法/主要发现：使用免疫组织化学方法，在两名胎儿和两名成人的舌、食管、胃、回肠、结肠、肝和胰腺的尸检标本中研究 Tβ4 的表达。Tβ4 分布不均，胎儿和成人之间存在明显差异。在胃中，胎儿的浅表上皮呈阳性，而成人的浅表上皮呈阴性。成人的回肠肠细胞呈强阳性，而胎儿的肠细胞呈弱阳性。与胎儿相比，成人结肠浅表上皮的 Tβ4 反应性增加。胎儿和成人肝脏之间存在明显差异：前者 Tβ4 反应性很低，而后者观察到绝大多数肝细胞强烈反应。胰腺的反应模式很特殊，胎儿和成人胰岛细胞的反应性最强。
我们的数据显示，Tβ4 在人肠道和内分泌胰腺的发育过程中表达强烈。Tβ4 的差异表达表明该肽在胎儿和成人肠道中的特定作用。在胎儿期，Tβ4 表达的异质性明显，从肝细胞中很少检测到到弥漫性反应到内分泌胰腺，在评估 Tβ4 在人胚胎发育中的作用时应考虑到这一点。未来的研究需要阐明 Tβ4 与器官发生之间的联系。
