Increased insulin-like growth factor 1 production by human osteoarthritic chondrocytes is not dependent on growth hormone action

✍ Scribed by Sylvain Doré; Thierry Abribat; Nicole Rousseau; Paul Brazeau; Ginette Tardif; John Anthony Dibattista; Jean-Marie Cloutier; Jean-Pierre Pelletier; Johanne Martel-Pelletier

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 772 KB
• Volume: 38
• Category: Article
• ISSN: 0004-3591
• DOI: 10.1002/art.1780380319

✦ Synopsis

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 '251-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 Dr.