The role of IGFBPs in the regulation of chondrocyte metabolism in vitro / by Damir Sunic.

Abstract

Insulin-like growth factors (IGFs) and inflammatory cytokines (e.g. IL-1) affect cartilage metabolism in opposite ways. The actions of IGFs in biological systems are modulated by locally produced IGF binding proteins (IGFBPs). This thesis investigated the effects of the IGFs and inflammatory cytokines on IGFBPs produced by chondrocytes and the subsequent interplay of these factors on proteoglycan production in vitro. To do this, a primary culture of ovine articular chondrocytes was used as an in vitro experimental model system. It was concluded that the IGFBP-5-mediated decrease in proteoglycan synthesis could be a relevant in vivo mechanism by which IL-1 exerts its catabolic effect and disturbs the balance between the synthesis and degradation of cartilage matrix macromolecules in pathological conditions.