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Updated: Jun 1, 2026

Software-Assisted Quantitative Measurement of Osteoarthritic Subchondral Bone Thickness
Published on: March 18, 2022
Age-dependent alteration of TGF-β signalling in osteoarthritis
Peter M van der Kraan1, Marie-José Goumans, Esmeralda Blaney Davidson
1Department of Rheumatology, Radboud University Nijmegen Medical Centre Nijmegen, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands. P.vanderkraan@reuma.umcn.nl
Abstract:
Osteoarthritis (OA) is a disease of articular cartilage, with aging as the main risk factor. In OA, changes in chondrocytes lead to the autolytic destruction of cartilage. Transforming growth factor-β has recently been demonstrated to signal not only via activin receptor-like kinase 5 (ALK5)-induced Smad2/3 phosphorylation, but also via ALK1-induced Smad1/5/8 phosphorylation in articular cartilage. In aging cartilage and experimental OA, the ratio ALK1/ALK5 has been found to be increased, and the expression of ALK1 is correlated with matrix metalloproteinase-13 expression. The age-dependent shift towards Smad1/5/8 signalling might trigger the differentiation of articular chondrocytes with an autolytic phenotype.
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