The influence of age on collagen and non-collagen protein production by human gingival epithelial cells.
The effects of donor age on the proliferation and secretory phenotype of cultured human gingival epithelial cells were investigated. Pure cultures of epithelial cells were isolated from human gingiva of old (61-75 yr) and young (18-30 yr) adults and serially cultivated in a serum-free medium at 37 degrees C in humidified air containing 5% CO2. For each experiment, cells were seeded at 150/mm2 and the medium changed every other day. Cell number, collagen and non-collagen protein production and relative collagen synthesis (percentage collagen synthesized) were determined at days 2, 4, 6 and 8. Epithelial strains from old and young adults became confluent by day 8 and there were no differences in their rates of proliferation. Likewise there was no difference in collagen production between the two groups; however, cells from elderly individuals produced significantly less non-collagen protein. Over time the decrease in non-collagen protein production ranged from 56% below the non-collagen protein levels of epithelium from young adults at day 2 to 24% below at day 8. The reduction of non-collagen protein coupled with the unchanged secretion of collagen resulted in a statistically significant increase in relative collagen synthesis by epithelial cells from elderly individuals. These differences in non-collagen protein production and relative collagen synthesis by cultured gingival epithelium of old adults suggest a selective conversion in protein secretion.
Mariotti
A
A
Department of Periodontology, College of Dentistry, University of Florida, Gainesville 32610.
Hassell
T
T
Kaminker
P
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging; D000704:Analysis of Variance; D002455:Cell Division; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis*; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D005881:Gingiva / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D015999:Multivariate Analysis; D014176:Protein Biosynthesis; D012044:Regression Analysis
D003094:Collagen