Modulation of cell proliferation and differentiation through substrate-dependent changes in fibronectin conformation
Modulation of cell proliferation and differentiation through substrate-dependent changes in fibronectin conformation
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DOI：
10.1091/mbc.10.3.785
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发表时间：
1999-03-01
影响因子：
3.3
通讯作者：
Boettiger, D
中科院分区：
文献类型：
--
作者：
García, AJ;Vega, MD;Boettiger, D
整合素介导的细胞与细胞外基质的粘附提供了细胞周期进展和分化所必需的信号。我们证明，吸附的纤连蛋白（Fn）构象的底物依赖性变化调节整合素结合并控制增殖和分化之间的切换。 Fn 吸附到细菌聚苯乙烯 (B)、组织培养聚苯乙烯 (T) 和胶原蛋白 (C) 上会导致 Fn 构象差异，如抗体结合所示。使用生化方法量化培养细胞中结合的整合素，我们发现 Fn 构象的差异改变了结合的 α(5) 和 β(1)、整合素亚基的数量，但不改变 α(v) 或 beta(3)。在这些 Fn 涂层基质上生长的 C2C12 成肌细胞增殖至不同水平 (B > T > C)。肌肉特异性肌球蛋白的免疫染色显示 B 上的分化程度最低，T 上的分化程度显着，而 C 上的分化程度很高。分化需要与 Fn 中的 RGD 细胞结合位点结合，并被对该位点具有特异性的抗体阻断。增殖和分化之间的转换受与 Fn 结合的 α(5)β(1) 整合素水平控制，抗 α(5) 抗体抑制分化，但抗 α(v) 抗体不抑制分化，这表明整合素介导的信号通路不同。通过细胞外基质蛋白的构象变化来控制细胞增殖和分化代表了一种在生物和生物技术应用中引发特定细胞反应的通用机制。
Integrin-mediated cell adhesion to extracellular matrices provides signals essential for cell cycle progression and differentiation. We demonstrate that substrate-dependent changes in the conformation of adsorbed fibronectin (Fn) modulated integrin binding and controlled switching between proliferation and differentiation. Adsorption of Fn onto bacterial polystyrene (B), tissue culture polystyrene (T), and collagen (C) resulted in differences in Fn conformation as indicated by antibody binding. Using a biochemical method to quantify bound integrins in cultured cells, we found that differences in Fn conformation altered the quantity of bound alpha(5) and beta(1), integrin subunits but not alpha(v), or beta(3). C2C12 myoblasts grown on these Fn-coated substrates proliferated to different levels (B > T > C). Immunostaining for muscle-specific myosin revealed minimal differentiation on B, significant levels on T, and extensive differentiation on C. Differentiation required binding to the RGD cell binding site in Fn and was blocked by antibodies specific for this site. Switching between proliferation and differentiation was controlled by the levels of alpha(5)beta(1) integrin bound to Fn, and differentiation was inhibited by anti-alpha(5) but not anti-alpha(v) antibodies, suggesting distinct integrin-mediated signaling pathways. Control of cell proliferation and differentiation through conformational changes in extracellular matrix proteins represents a versatile mechanism to elicit specific cellular responses for biological and biotechnological applications.