Keratocyte phenotype mediates proteoglycan structure - A role for fibroblasts in corneal fibrosis
Keratocyte phenotype mediates proteoglycan structure - A role for fibroblasts in corneal fibrosis
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DOI：
10.1074/jbc.m303292200
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发表时间：
2003-11-14
影响因子：
4.8
通讯作者：
Funderburgh, ML
中科院分区：
文献类型：
--
作者：
Funderburgh, JL;Mann, MM;Funderburgh, ML
在病理性角膜中，纤维性细胞外基质的堆积以蛋白多糖和糖胺聚糖的改变为特征，这有助于减少瘢痕组织的透明度。在伤口愈合过程中，角膜基质中的角质形成细胞转化为成纤维细胞和肌成纤维细胞。在这项研究中，我们开发了分子标记来鉴定原代培养的角膜基质细胞中的角质细胞、成纤维细胞和肌成纤维细胞的表型，并对这些细胞分泌的糖胺聚糖的结构进行了表征。静止的原代角质形成细胞表达丰富的角蛋白聚糖和乙醛脱氢酶3类蛋白和mRNA，并分泌含有大分子角蛋白硫酸酯的蛋白多糖。这些标记化合物在成纤维细胞中的表达减少，在转化生长因子-β诱导的肌成纤维细胞中也是如此，后者表达高水平的α-平滑肌肌动蛋白、Biglycan和细胞纤维连接蛋白的额外结构域A(EDA或EIIIA)形式。I型和III型胶原在成纤维细胞和肌成纤维细胞中均升高。这些分子标记的表达清楚地区分了体外培养的基质细胞的表型状态。成纤维细胞和肌成纤维细胞分泌的糖胺多糖与角质形成细胞分泌的糖胺聚糖在性质上既相似又不同。当角质形成细胞变成成纤维细胞和肌成纤维细胞时，硫酸软骨素/皮肤素的丰度、链长度和硫酸盐化程度都会增加。荧光团辅助碳水化合物电泳分析表明，N-乙酰氨基半乳糖在4-碳和6-碳上的磺化程度都增加了。透明质酸由成纤维细胞和肌成纤维细胞分泌，角质形成细胞中不存在透明质酸。在成纤维细胞和肌成纤维细胞中，角蛋白硫酸盐的生物合成、链长度和硫酸盐化都显著减少。成纤维细胞和肌成纤维细胞共有的糖胺多聚糖的表达在性质上相似，这表明成纤维细胞在病理性角膜中非透明纤维组织的沉积中发挥了作用。
In pathological corneas, accumulation of fibrotic extracellular matrix is characterized by proteoglycans with altered glycosaminoglycans that contribute to the reduced transparency of scarred tissue. During wound healing, keratocytes in the corneal stroma transdifferentiate into fibroblasts and myofibroblasts. In this study, molecular markers were developed to identify keratocyte, fibroblast, and myofibroblast phenotypes in primary cultures of corneal stromal cells and the structure of glycosaminoglycans secreted by these cells was characterized. Quiescent primary keratocytes expressed abundant protein and mRNA for keratocan and aldehyde dehydrogenase class 3 and secreted proteoglycans containing macromolecular keratan sulfate. Expression of these marker compounds was reduced in fibroblasts and also in transforming growth factor-beta-induced myofibroblasts, which expressed high levels of alpha-smooth muscle actin, biglycan, and the extra domain A (EDA or EIIIA) form of cellular fibronectin. Collagen types I and III mRNAs were elevated in both fibroblasts and in myofibroblasts. Expression of these molecular markers clearly distinguishes the phenotypic states of stromal cells in vitro. Glycosaminoglycans secreted by fibroblasts and myofibroblasts were qualitatively similar to and differed from those of keratocytes. Chondroitin/dermatan sulfate abundance, chain length, and sulfation were increased as keratocytes became fibroblasts and myofibroblasts. Fluorophore-assisted carbohydrate electrophoresis analysis demonstrated increased N-acetylgalactosamine sulfation at both 4- and 6-carbons. Hyaluronan, absent in keratocytes, was secreted by fibroblasts and myofibroblasts. Keratan sulfate biosynthesis, chain length, and sulfation were significantly reduced in both fibroblasts and myofibroblasts. The qualitatively similar expression of glycosaminoglycans shared by fibroblasts and myofibroblasts suggests a role for fibroblasts in deposition of non-transparent fibrotic tissue in pathological corneas.