Myofibroblasts differentiate from fibroblasts when plated at low density
Myofibroblasts differentiate from fibroblasts when plated at low density
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DOI：
10.1073/pnas.93.9.4219
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发表时间：
1996-04-30
影响因子：
11.1
通讯作者：
Petridou, S
中科院分区：
文献类型：
--
作者：
Masur, SK;Dewal, HS;Petridou, S
肌成纤维细胞由其表达的平滑肌α-肌动蛋白定义，出现在角膜和真皮切口处，促进伤口收缩。我们在这里报道，培养的成纤维细胞通过细胞密度依赖的机制分化为肌成纤维细胞。以低密度(5个/mm(2))接种的成纤维细胞在接种后5-7天产生由70-80%的肌成纤维细胞组成的细胞培养群。相反，以高密度(500个/mm(2))种植的成纤维细胞产生的培养物中只有5-10%的肌成纤维细胞。当富含肌成纤维细胞的培养物随后以高密度传代时，平滑肌α-肌动蛋白表型在3天内就消失了。此外，最初60%的低密度培养细胞含有BrdUrd，而在高密度培养的细胞中，这一比例为30%。肌成纤维细胞增强型培养基比成纤维细胞增强型培养基有更多的转化生长因子-β潜伏期和活性。尽管加入外源性转化生长因子-β后有增加肌成纤维细胞数量的趋势，但结果没有达到统计学意义。我们认为，低密度培养可以诱导成纤维细胞分化为肌成纤维细胞。我们提出了一个创伤和愈合过程中肌成纤维细胞分化的细胞密度依赖的模型，其中至少有两个因素相互作用：细胞接触的丧失和转化生长因子-β的存在。
Myofibroblasts, defined by their expression of smooth muscle alpha-actin, appear at corneal and dermal incisions and promote wound contraction. We report here that cultured fibroblasts differentiate into myofibroblasts by a cell density-dependent mechanism. Fibroblasts seeded at low density (5 cells per mm(2)) produced a cell culture population consisting of 70-80% myofibroblasts, 5-7 days after seeding. In contrast, fibroblasts seeded at high density (500 cells per mm(2)) produced cultures with only 5-10% myofibroblasts. When the myofibroblast-enriched cultures were subsequently passaged at high density, the smooth muscle alpha-actin phenotype was lost within 3 days. Furthermore, initially 60% of the low-density-cultured cells incorporated BrdUrd compared to 30% of cells passaged at high density. Media from myofibroblast-enriched cultures had more latent and active transforming growth factor beta (TGF-beta) than did media from fibroblast-enriched cultures. Although there was a trend towards increased numbers of myofibroblasts after addition of exogenous TGF-beta, the results did not reach statistical significance. We conclude that myofibroblast differentiation can be induced in fibroblasts by plating at low density. We propose a cell density-dependent model of myofibroblast differentiation during wounding and healing in which at least two factors interact: loss of cell contact and the presence of TGF-beta.