| First Author | Wilson S | Year | 2009 |
| Journal | Am J Pathol | Volume | 175 |
| Issue | 5 | Pages | 2053-62 |
| PubMed ID | 19834056 | Mgi Jnum | J:154691 |
| Mgi Id | MGI:4397742 | Doi | 10.2353/ajpath.2009.090211 |
| Citation | Wilson S, et al. (2009) Glycosaminoglycan-mediated loss of cathepsin K collagenolytic activity in MPS I contributes to osteoclast and growth plate abnormalities. Am J Pathol 175(5):2053-62 |
| abstractText | Mucopolysaccharidoses are a group of lysosomal storage diseases characterized by the build-up of glycosaminoglycans (GAGs) and severe skeletal abnormalities. As GAGs can regulate the collagenolytic activity of the major osteoclastic protease cathepsin K, we investigated the presence and activity of cathepsin K and its co-localization with GAGs in mucopolysaccharidosis (MPS) type I bone. The most dramatic difference between MPS I and wild-type mice was an increase in the amount of cartilage in the growth plates in MPS I bones. Though the number of cathepsin K-expressing osteoclasts was increased in MPS I mice, these mice revealed a significant reduction in cathepsin K-mediated cartilage degradation. As excess heparan and dermatan sulfates inhibit type II collagen degradation by cathepsin K and the spatial overlap between cathepsin K and heparan sulfate strongly increased in MPS I mice, the build up of subepiphyseal cartilage is speculated to be a direct consequence of cathepsin K inhibition by MPS I-associated GAGs. Moreover, isolated MPS I and Ctsk(-/-) osteoclasts displayed fewer actin rings and formed fewer resorption pits on dentine disks, as compared with wild-type cells. These results suggest that the accumulation of GAGs in murine MPS I bone has an inhibitory effect on cathepsin K activity, resulting in impaired osteoclast activity and decreased cartilage resorption, which may contribute to the bone pathology seen in MPS diseases. |
