Maring J A, van Meeteren L A, Goumans M J, Ten Dijke Peter
Department of Molecular Cell Biology, Cancer Genomics Centre Netherlands, Centre for Biomedical Genetics, Leiden University Medical Center, Postzone S-1-P, Postbus 9600, 2300 RC, Leiden, The Netherlands.
Methods Mol Biol. 2016;1344:193-203. doi: 10.1007/978-1-4939-2966-5_11.
Transforming growth factor-β (TGF-β) is a multifunctional cytokine with important roles in embryogenesis and maintaining tissue homeostasis during adult life. There are three isoforms of TGF-β, i.e., TGF-β1, -β2, and -β3, which signal by binding to a complex of transmembrane type I and type II serine/threonine kinase receptors and intracellular Smad transcription factors. In most cell types TGF-β signals via TGF-β type II receptor (TβRII) and TβRI, also termed activin receptor-like kinase 5 (ALK5). In endothelial cells, TGF-β signals via ALK5 and ALK1. These two type I receptors mediate opposite cellular response for TGF-β. The co-receptor endoglin, highly expressed on proliferating endothelial cells, facilitates TGF-β/ALK1 and inhibits TGF-β/ALK5 signaling. Knockout of TGF-β receptors in mice all result in embryonic lethality during midgestation from defects in angiogenesis, illustrating the pivotal role of TGF-β in this process. This chapter introduces methods for examining the function and regulation of TGF-β in angiogenesis in in vitro assays using cultured endothelial cells and ex vivo metatarsal explants.
转化生长因子-β（TGF-β）是一种多功能细胞因子，在胚胎发育以及成年期维持组织内稳态过程中发挥着重要作用。TGF-β有三种亚型，即TGF-β1、-β2和 -β3，它们通过与跨膜I型和II型丝氨酸/苏氨酸激酶受体以及细胞内Smad转录因子复合物结合来传递信号。在大多数细胞类型中，TGF-β通过TGF-β II型受体（TβRII）和TβRI（也称为激活素受体样激酶5，ALK5）传递信号。在内皮细胞中，TGF-β通过ALK5和ALK1传递信号。这两种I型受体介导TGF-β产生相反的细胞反应。共受体内皮糖蛋白在增殖的内皮细胞上高度表达，促进TGF-β/ALK-1信号传导并抑制TGF-β/ALK-5信号传导。在小鼠中敲除TGF-β受体均会导致妊娠中期因血管生成缺陷而出现胚胎致死，这说明了TGF-β在此过程中的关键作用。本章介绍了使用培养的内皮细胞和离体跖骨外植体在体外试验中检测TGF-β在血管生成中的功能和调节的方法。
