Kähäri V M, Larjava H, Uitto J
Department of Dermatology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
J Biol Chem. 1991 Jun 5;266(16):10608-15.
Proteoglycans (PGs) comprise a group of extracellular matrix macromolecules which play an important role in matrix biology. In this study, normal human skin and gingival fibroblast cultures were incubated with transforming growth factor-beta 1 (TGF-beta 1), and the expression of three PGs, viz. biglycan (PGI), decorin (PGII), and versican (a large fibroblast proteoglycan) was examined. The results indicate that TGF-beta 1 (5 ng/ml) markedly increased the expression of biglycan (up to 24-fold) and versican (up to 6-fold) mRNAs and the enhancement of biglycan expression was coordinate with elevated type I procollagen gene expression in the same cultures. In contrast, the expression of decorin mRNA was markedly (up to approximately 70%) inhibited by TGF-beta 1. The response to TGF-beta 1 was similar in both skin and gingival fibroblasts, although the gingival cells were clearly more responsive to stimulation by TGF-beta 1 with respect to biglycan gene expression. Analysis of 35S-labeled proteoglycans in the culture media of skin and gingival fibroblasts also revealed stimulation of biglycan and versican production, and reduction in decorin production. Quantitation of both [35S]sulfate and [3H]leucine-labeled decorin in cell culture media by immunoprecipitation revealed a 50% reduction in decorin production in cell cultures treated with TGF-beta 1. This TGF-beta 1-elicited reduction was accompanied by an apparent increase in the size of the decorin molecules, although the size of the core protein was not altered, as judged by Western immunoblotting following chondroitinase ABC digestion. Analysis of the proteoglycans in the matrix and membrane fractions also revealed increased amounts of versican in cultures treated with TGF-beta 1. These results indicate differential regulation of PG gene expression in fibroblasts by TGF-beta 1, and these observations emphasize the role of PGs in the extracellular matrix biology and pathology.
蛋白聚糖（PGs）是一组细胞外基质大分子，在基质生物学中发挥重要作用。在本研究中，将正常人皮肤和牙龈成纤维细胞培养物与转化生长因子-β1（TGF-β1）一起孵育，并检测三种蛋白聚糖，即双糖链蛋白聚糖（PGI）、饰胶蛋白聚糖（PGII）和多功能蛋白聚糖（一种大型成纤维细胞蛋白聚糖）的表达。结果表明，TGF-β1（5 ng/ml）显著增加了双糖链蛋白聚糖（高达24倍）和多功能蛋白聚糖（高达6倍）mRNA的表达，并且在相同培养物中双糖链蛋白聚糖表达的增强与I型前胶原基因表达的升高相一致。相反，TGF-β1显著抑制（高达约70%）饰胶蛋白聚糖mRNA的表达。皮肤和牙龈成纤维细胞对TGF-β1的反应相似，尽管就双糖链蛋白聚糖基因表达而言，牙龈细胞对TGF-β1刺激的反应明显更强。对皮肤和牙龈成纤维细胞培养基中35S标记的蛋白聚糖的分析还显示，双糖链蛋白聚糖和多功能蛋白聚糖的产生受到刺激，而饰胶蛋白聚糖的产生减少。通过免疫沉淀对细胞培养基中[35S]硫酸盐和[3H]亮氨酸标记的饰胶蛋白聚糖进行定量分析，结果显示用TGF-β1处理的细胞培养物中饰胶蛋白聚糖的产生减少了50%。这种由TGF-β1引起的减少伴随着饰胶蛋白聚糖分子大小的明显增加，尽管根据软骨素酶ABC消化后的Western免疫印迹判断，核心蛋白的大小没有改变。对基质和膜部分中的蛋白聚糖进行分析还显示，用TGF-β1处理的培养物中多功能蛋白聚糖的量增加。这些结果表明TGF-β1对成纤维细胞中PG基因表达的调控存在差异，并且这些观察结果强调了蛋白聚糖在细胞外基质生物学和病理学中的作用。
