Armatas Andreas A, Pratsinis Harris, Mavrogonatou Eleni, Angelopoulou Maria T, Kouroumalis Anastasios, Karamanos Nikos K, Kletsas Dimitris
Laboratory for Cell Proliferation & Ageing, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", 153 10 Athens, Greece.
Laboratory of Biochemistry, Department of Chemistry, University of Patras, 26110 Patras, Greece.
Biochim Biophys Acta. 2014 Aug;1840(8):2635-42. doi: 10.1016/j.bbagen.2014.04.004. Epub 2014 Apr 13.
Transforming growth factor-β is a multifunctional and pleiotropic factor with decisive role in tissue repair. In this context, we have shown previously that TGF-β inhibits the proliferation of fetal human skin fibroblasts but stimulates that of adult ones. Given the dynamic reciprocity between fibroblasts, growth factors and extracellular matrix (ECM) in tissue homeostasis, the present study aims to investigate the role of fibronectin and collagen in the proliferative effects of TGF-β on fetal and adult cells.
Human fetal and adult skin fibroblasts were grown either on plastic surfaces or on surfaces coated with fibronectin or collagen type-I, as well as, on top or within three-dimensional matrices of polymerized collagen. Their proliferative response to TGF-β was studied using tritiated thymidine incorporation, while the signaling pathways involved were investigated by Western analysis and using specific kinase inhibitors.
Fetal skin fibroblast-proliferation was inhibited by TGF-β, while that of adult cells was stimulated by this factor, irrespective of the presence of fibronectin or collagen. Both inhibitory and stimulatory activities of TGF-β on the proliferation of fetal and adult fibroblasts, respectively, were abrogated when the Smad pathway was blocked. Moreover, inhibition of fetal fibroblasts was mediated by PKA activation, while stimulation of adult ones was effected through the autocrine activation of FGF receptor and the MEK-ERK pathway.
Fetal and adult human skin fibroblasts retain their differential proliferative response to TGF-β when cultured in the presence of fibronectin and unpolymerized or polymerized collagen.
The interplay between TGF-β and ECM supports the pleiotropic nature of this growth factor, in concordance with the different repair strategies between fetuses and adults. This article is part of a Special Issue entitled Matrix-mediated cell behaviour and properties.
转化生长因子-β是一种多功能且具有多效性的因子，在组织修复中起决定性作用。在此背景下，我们之前已表明，转化生长因子-β抑制胎儿人皮肤成纤维细胞的增殖，但刺激成人皮肤成纤维细胞的增殖。鉴于成纤维细胞、生长因子和细胞外基质（ECM）在组织稳态中的动态相互作用，本研究旨在探讨纤连蛋白和胶原蛋白在转化生长因子-β对胎儿和成人细胞增殖作用中的作用。
将人胎儿和成人皮肤成纤维细胞培养在塑料表面、涂有纤连蛋白或I型胶原蛋白的表面，以及聚合胶原蛋白的三维基质之上或其中。使用氚标记胸腺嘧啶核苷掺入法研究它们对转化生长因子-β的增殖反应，同时通过蛋白质印迹分析和使用特异性激酶抑制剂来研究相关信号通路。
无论是否存在纤连蛋白或胶原蛋白，转化生长因子-β均抑制胎儿皮肤成纤维细胞的增殖，而刺激成人细胞的增殖。当Smad信号通路被阻断时，转化生长因子-β对胎儿和成人成纤维细胞增殖的抑制和刺激活性均被消除。此外，胎儿成纤维细胞的抑制是由蛋白激酶A激活介导的，而成人成纤维细胞的刺激是通过成纤维细胞生长因子受体的自分泌激活和MEK-ERK信号通路实现的。
在纤连蛋白以及未聚合或聚合胶原蛋白存在的情况下培养时，胎儿和成人皮肤成纤维细胞对转化生长因子-β仍保持不同的增殖反应。
转化生长因子-β与细胞外基质之间的相互作用支持了这种生长因子的多效性，这与胎儿和成人不同的修复策略相一致。本文是名为“基质介导的细胞行为和特性”的特刊的一部分。
