Differential effects of aging on human chondrocyte responses to transforming growth factor β. Increased pyrophosphate production and decreased cell proliferation
✍ Scribed by Fred Rosen; Greg McCabe; Jacqueline Quach; Joell Solan; Robert Terkeltaub; J. Edwin Seegmiller; Martin Lotz
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 758 KB
- Volume
- 40
- Category
- Article
- ISSN
- 0004-3591
No coin nor oath required. For personal study only.
✦ Synopsis
Objective. To address the influence of age on inorganic pyrophosphate (PPi) accumulation in human articular chondrocytes.
Methods. Articular cartilage was obtained from men and women in 2 different age groups: ages 15-55 and 56-91. The effects of transforming growth factor Pl (TGFP1) on PPi levels in the media and cell lysates of chondrocytes were investigated. In addition, the effects of TGFP on PPi accumulation were compared with chondrocyte proliferation.
Results. TGFPl increased PPi levels to a greater extent in chondrocytes from subjects in the older age group compared with those obtained from younger subjects. Treatment of chondrocytes with TGFPl led to a similar increase in total intracellular protein in both age groups. Although TGFP increased nucleoside triphosphate pyrophosphohydrolase activity and decreased alkaline phosphatase activity, these effects did not differ between the 2 age groups. Analysis of the same cell preparations showed an age-related decrease in TGFP-induced chondrocyte proliferation, whereas these same cells showed an increased response with respect to PPi elaboration.
Conclusion. These results show that aging differentially affected TGFP-induced PPi accumulation ver-