Interleukin-1 and Transforming Growth Factor-ß 1 as Crucial Factors in Osteoarthritic Cartilage Metabolism

Abstract

In osteoarthritis (OA), interleukin-1 (IL-1) stimulates the expression of metalloproteinases and aggrecanases, which induce cartilage degradation. IL-1 is also capable of reducing the production of cartilage-specific macromolecules, including type II collagen, through modulation of the transcription factors Sp1 and Sp3. Conversely, Transforming growth factor-ß (TGF-β) counteracts with most of the IL-1 deleterious effects and contributes to cartilage homeostasis. However, OA chondrocytes progressively loose the expression of TGF-β type II receptor and become insensitive to the factor. This downregulation is also driven by IL-1. This review provides insights into the molecular mechanisms that underly the interplay between IL-1 and TGF-β in OA cartilage metabolism and enlightens the central role of Sp1 and Sp3 transcription factors in the matrix pathological alterations.

Keywords:

• Osteoarthritis
• Cartilage
• Interleukin-1
• Transforming Growth Factor-ß Type II Receptor
• Type II Collagen