Gremlin 1, Frizzled-related protein, and Dkk-1 are key regulators of human articular cartilage homeostasis


Leijten, J.C.H. and Emons, J. and Sticht, C. and Gool, S. van and Decker, E. and Uitterlinden, A. and Rappold, G. and Hofman, A. and Rivadeneira, F. and Scherjon, S. and Wit, J.M. and Meurs, J. van and Blitterswijk, C.A. van and Karperien, H.B.J. (2012) Gremlin 1, Frizzled-related protein, and Dkk-1 are key regulators of human articular cartilage homeostasis. Arthritis & rheumatism, 64 (10). 3302 - 3312. ISSN 0004-3591

PDF (Accepted paper)
[img] PDF (Published version)
Restricted to UT campus only
: Request a copy
PDF (Research highlight Nature reviews rheumatology)

The development of osteoarthritis (OA) may be caused by activation of hypertrophic differentiation of articular chondrocytes. Healthy articular cartilage is highly resistant to hypertrophic differentiation, in contrast to other hyaline cartilage subtypes, such as growth plate cartilage. The purpose of this study was to elucidate the molecular mechanism responsible for the difference in the propensity of human articular cartilage and growth plate cartilage to undergo hypertrophic differentiation.


Whole-genome gene-expression microarray analysis of healthy human growth plate and articular cartilage derived from the same adolescent donors was performed. Candidate genes, which were enriched in the articular cartilage, were validated at the messenger RNA (mRNA) and protein levels and examined for their potential to inhibit hypertrophic differentiation in two models. In addition, we studied a possible genetic association with OA.


Pathway analysis demonstrated decreased Wnt signaling in articular cartilage as compared to growth plate cartilage. This was at least partly due to increased expression of the bone morphogenetic protein and Wnt antagonists Gremlin 1, Frizzled-related protein (FRP), and Dkk-1 at the mRNA and protein levels in articular cartilage. Supplementation of these proteins diminished terminal hypertrophic differentiation without affecting chondrogenesis in long-bone explant cultures and chondrogenically differentiating human mesenchymal stem cells. Additionally, we found that single-nucleotide polymorphism rs12593365, which is located in a genomic control region of GREM1, was significantly associated with a 20% reduced risk of radiographic hip OA in 2 population-based cohorts.


Taken together, our study identified Gremlin 1, FRP, and Dkk-1 as natural brakes on hypertrophic differentiation in articular cartilage. As hypertrophic differentiation of articular cartilage may contribute to the development of OA, our findings may open new avenues for therapeutic intervention.
Item Type:Article
Copyright:© 2012 American College of Rheumatology
Science and Technology (TNW)
Research Group:
Link to this item:
Official URL:
Export this item as:BibTeX
HTML Citation
Reference Manager


Repository Staff Only: item control page

Metis ID: 293084