Woodley D T, Wynn K C, O'Keefe E J
Department of Dermatology, University of North Carolina School of Medicine, Chapel Hill.
J Invest Dermatol. 1990 Jan;94(1):139-43. doi: 10.1111/1523-1747.ep12873992.
In various cell culture systems, extracellular matrix components have been demonstrated to be mitogenic and, in some cases, to substitute for growth factors. In order to study the effects of various matrices on keratinocyte growth, we assessed the incorporation of tritiated thymidine and cell number on short-term cultures of human keratinocytes plated on different substrata. For determination of whether thymidine incorporation by keratinocytes was related to the ability of the cells to attach and spread on the substratum, experiments to determine the percentage of attached and spread cells on each matrix surface were performed. High levels of attachment and incorporation of thymidine with no preferential attachment to a given matrix were evident when the cells were cultured in the presence of growth factors. When growth factors were absent, keratinocytes likewise showed no preferential attachment to a given matrix component, but demonstrated enhanced thymidine incorporation when apposed to type IV collagen or fibronectin in comparison with tissue culture plastic or laminin. In the absence of epidermal growth factor (EGF) and bovine pituitary extract (BPE), increased spreading on type IV collagen and fibronectin was associated with enhanced incorporation of thymidine. In agreement with the thymidine incorporation results, when keratinocytes were cultured for 7 d, cell numbers were increased in cultures plated on type IV collagen only if growth factors were excluded from the medium. When attachment of cells to substrata with or without growth factors was compared, either EGF or BPE enhanced attachment to all of the substrata tested. It is concluded that under suboptimal growth conditions extracellular matrix components can modulate keratinocyte growth. Also, under these conditions, spreading, but not attachment, correlates with growth potential.
在各种细胞培养系统中，细胞外基质成分已被证明具有促有丝分裂作用，并且在某些情况下可替代生长因子。为了研究各种基质对角质形成细胞生长的影响，我们评估了接种在不同基质上的人角质形成细胞短期培养物中氚标记胸腺嘧啶核苷的掺入情况和细胞数量。为了确定角质形成细胞对胸腺嘧啶核苷的掺入是否与细胞在基质上附着和铺展的能力有关，我们进行了实验以确定每种基质表面上附着和铺展细胞的百分比。当细胞在生长因子存在的情况下培养时，胸腺嘧啶核苷的高掺入水平以及对特定基质无优先附着现象很明显。当不存在生长因子时，角质形成细胞同样对特定基质成分没有优先附着，但与组织培养塑料或层粘连蛋白相比，当与IV型胶原或纤连蛋白接触时，其胸腺嘧啶核苷掺入增加。在缺乏表皮生长因子（EGF）和牛垂体提取物（BPE）的情况下，在IV型胶原和纤连蛋白上增加的铺展与胸腺嘧啶核苷掺入增加有关。与胸腺嘧啶核苷掺入结果一致，当角质形成细胞培养7天时，仅在培养基中不含生长因子的情况下，接种在IV型胶原上的培养物中的细胞数量才会增加。当比较细胞在有无生长因子情况下与基质的附着情况时，EGF或BPE均可增强细胞对所有测试基质的附着。得出的结论是，在次优生长条件下，细胞外基质成分可调节角质形成细胞的生长。此外，在这些条件下，铺展而非附着与生长潜力相关。
