Fibroblast growth factor-2 promotes keratan sulfate proteoglycan expression by keratocytes in vitro
Fibroblast growth factor-2 promotes keratan sulfate proteoglycan expression by keratocytes in vitro
复制标题
DOI：
10.1074/jbc.275.18.13918
复制
发表时间：
2000-05-05
影响因子：
4.8
通讯作者：
Funderburgh, JL
中科院分区：
文献类型：
--
作者：
Long, CJ;Roth, MR;Funderburgh, JL
角膜基质的角质细胞产生一种特殊的细胞外基质，负责角膜透明。角膜硫酸角蛋白多糖（KSPG）是角膜细胞的独特产物，在角膜创面和体外被下调。本研究利用原代牛角化细胞的培养来确定影响KSPG体外表达的因素。用[S-35]硫酸盐代谢标记的KSPG在低血清浓度（0.1%）的静止培养物培养的最初2-4天内减少。添加胎牛血清、成纤维细胞生长因子-2 （FGF-2）、转化生长因子β或血小板衍生生长因子都能刺激细胞分裂，但只有FGF-2能刺激KSPG分泌。与血清联合，FGF-2也能阻止血清诱导的KSPG下调。在有或没有FGF-2的连续传代培养过程中，KSPG分泌丢失，FGF-2刺激了KSPG核心蛋白（lumican， mimecan和keratocan）的表达，这些蛋白（尤其是keratocan）的稳态mRNA库在FGF-2处理下显着增加。因此，RSPG的表达由外源性FGF-2支持，并在血清存在的情况下通过细胞传代培养消除。FGF-2主要通过mRNA库的增加刺激RSPG核心蛋白的表达。
Keratocytes of the corneal stroma produce a specialized extracellular matrix responsible for corneal transparency. Corneal keratan sulfate proteoglycans (KSPG) are unique products of keratocytes that are down-regulated in corneal wounds and in vitro. This study used cultures of primary bovine keratocytes to define factors affecting KSPG expression in vitro. KSPG metabolically labeled with [S-35]sulfate decreased during the initial 2-4 days of culture in quiescent cultures with low serum concentrations (0.1%). Addition of fetal bovine serum, fibroblast growth factor-2 (FGF-2), transforming growth factor beta, or platelet derived growth factor all stimulated cell division, but only FGF-2 stimulated KSPG secretion. Combined with serum, FGF-2 also prevented serum-induced KSPG down-regulation. KSPG secretion was lost during serial subculture with or without FGF-2, Expression of KSPG core proteins (lumican, mimecan, and keratocan) was stimulated by FGF-2, and steady state mRNA pools for these proteins, particularly keratocan, were significantly increased by FGF-2 treatment. RSPG expression therefore is supported by exogenous FGF-2 and eliminated by subculture of the cells in presence of serum. FGF-2 stimulates RSPG core protein expression primarily through an increase in mRNA pools.