The effects of interleukin-1 on the expression of thrombospondin and fibronectin by rabbit articular chondrocytes*1

Autor: E. C. Arner, B Lyons-Giordano, Nicholas A. Kefalides, M. A. Pratta, Jane M. Brinker
Rok vydání: 1991
Předmět:
Zdroj: Experimental Cell Research. 195:462-467
ISSN: 0014-4827
DOI: 10.1016/0014-4827(91)90397-d
Popis: Studies to evaluate the effects of recombinant interleukin-1 beta (IL-1) on the expression of matrix proteins by rabbit articular chondrocytes were conducted. Chondrocytes expressed high levels of message for thrombospondin (Tsp) and fibronectin (Fn). RNA slot-blot analysis demonstrated that treatment of the cultures with IL-1 (100 ng/ml) for 24 h caused a 70% suppression of their steady-state Tsp mRNA levels whereas those of Fn were not affected. Steady-state mRNA levels for the intracellular protein, actin, were not modulated by treatment with IL-1. The suppression of Tsp mRNA levels by IL-1 (100 ng/ml) was maximal by 4 h and was concentration dependent; half-maximal suppression was estimated to require 0.12 ng/ml IL-1. Cycloheximide treatment enhanced Tsp mRNA levels, but did not modulate IL-1 suppression of Tsp mRNA. Using pulse-labeling and immunoprecipitation techniques, we found that IL-1 suppression of Tsp mRNA levels was reflected in a coordinate inhibition of Tsp protein synthesis. Chondrocyte synthesis of Fn was not affected by IL-1. These data suggest that IL-1 specifically regulates chondrocyte expression of Tsp at least in part by decreasing the amount of Tsp mRNA available for translation.
Databáze: OpenAIRE