[Influence of glycosaminoglycan synthesis of cultured cornea stroma cells by variation of culture condition]

Abstract

Cultured cells derived from bovine corneal stroma synthesize all types of sulfated glycosaminoglycans and distribute these macromolecules into topographically different compartments in a reproducible manner. Each compartment is characterized by a typical glycosaminoglycan distribution pattern. Corneal fibroblasts synthesize in vitro only small amounts of keratan sulfate in contrast to the in vivo conditions. We have, therefore, investigated the synthesis and topographical distribution of sulfated glycosaminoglycans as influenced by different culture conditions. The following results were obtained: 1) Cocultivation of epithelial and stromal fibroblasts from bovine cornea led to an increased incorporation of radiosulfate into sulfated glycosaminoglycans by about 50% as compared to the theoretical value. Glycosaminoglycan distribution of mixed cultures into different compartments showed no similarity compared with pure epithelial or stromal fibroblasts. 2) Addition of native or heat inactivated anterior chamber fluid to the culture medium was followed by a twofold increase of [35S]-sulfate incorporation and by an augmented intracellular and pericellular accumulation of labeled macromolecules. 3) Reduction of the incubation temperature led to a reduced synthesis of glycosaminoglycans without influencing their topographical distribution. Growth of stromal cells on type I collagen was accompanied by a reduced glycosaminoglycan synthesis of about 25%. Extracellular macromolecules reached only half of the normal value, while intracellularly their concentration was slightly increased. 4) None of the variations of the culture condition led to a significant change of the distribution pattern of sulfated glycosaminoglycans. Especially, no significant increase of keratan sulfate biosynthesis could be detected.