Increased insulin‐like growth factor 1 production by human osteoarthritic chondrocytes is not dependent on growth hormone action
1995; Wiley; Volume: 38; Issue: 3 Linguagem: Inglês
10.1002/art.1780380319
ISSN1529-0131
AutoresSylvain Doré, Thierry Abribat, Nicole Rousseau, Paul Brazeau, Ginette Tardif, John A. DiBattista, Jean‐Marie Cloutier, Jean‐Pierre Pelletier, Johanne Martel‐Pelletier,
Tópico(s)Cancer-related molecular mechanisms research
ResumoAbstract Objective . To investigate insulin‐like growth factor 1 (IGF‐1) production in normal and osteoarthritis (OA) chondrocytes and to further examine the role of growth hormone (GH) in adult human cartilage and, in particular, in diseased tissue. Methods . IGF‐1 production was measured with a radioimmunoassay. Binding assay, Northern blot, and reverse transcriptase polymerase chain reaction (RT‐PCR) techniques were used for GH receptor (GHR) detection. The biological response to GH was estimated via IGF‐1 production. Results . We observed that basal levels of IGF‐1 production were significantly higher in OA chondrocytes than in normal cells ( P < 0.005). Adult human chondrocytes, however, were unresponsive to GH stimulation with regard to IGF‐1 production, as shown in dose‐response (0–1,000 ng/ml) and time‐course (days 1–8) studies. In addition, no specific 125 I‐GH binding was detected in either cell type. Northern blot analysis revealed a 5.5‐kb GHR messenger RNA (mRNA) species, but semiquantitative RT‐PCR revealed no difference in GHR mRNA expression by normal and OA chondrocytes. Conclusion . This study indicates that the elevated synthesis of IGF‐1 by adult human OA chondrocytes occurs through a GH/GHR‐independent mechanism, suggesting that other factors are capable of controlling local IGF‐1 production in these cells.
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