Collagen and glycosaminoglycan synthesis in aging human keratocyte cultures

• Published in: Experimental eye research Vol. 32; no. 3; pp. 331 - 339
• Main Authors: Birk, David E., Lande, Mauricio A., Fernandez-Madrid, Felix R.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.1981
• Subjects: aging; Cell Survival; Cells, Cultured; collagen; Collagen - biosynthesis; Cornea - metabolism; culture; Electrophoresis, Polyacrylamide Gel; glycosaminoglycans; Glycosaminoglycans - biosynthesis; Humans; keratocyte; procollagen; glycosaminoglycans; collagen; procollagen; keratocyte; aging; culture
• ISSN: 0014-4835; 1096-0007
• DOI: 10.1016/0014-4835(81)90038-5

Human corneal keratocytes were serially subcultured and the synthesis and secretion of collagen and glycosaminoglycans (GAGs) were studied as a function of increasing culture age in five different keratocyte strains. With repeated passage these cultures showed a significant decrease in the synthesis and secretion of total protein, collagen, and GAGs into the culture medium. These events were observed as gradual changes over a significant portion of the keratocyte's lifespan. Cultures at all ages studied synthesized and secreted type I procollagen. At all passage levels studied hyaluronic acid, dermatan sulfate, heparan sulfate, chondroitin 4-sulfate, chondroitin 6-sulfate, and non-sulfated chondroitin were present in the culture medium. Sepharose 6B chromatography of the GAG fractions from young and old keratocyte cultures showed similar size ranges with no age associated decrease in GAG chain length to account for the observed decrease in GAG synthesis. Thus, cellular aging is an important factor in the evaluation of the synthetic potential of human keratocytes in culture. However, in our system the phenotypic expression of the major extracellular matrix components seems to be independent of aging in culture.