Heparan Sulfate Proteoglycan Synthesis is Dysregulated in Human Osteoarthritic Cartilage.

Heparan Sulfate Proteoglycan Synthesis is Dysregulated in Human Osteoarthritic Cartilage. Am J Pathol. 2018 Dec 13;: Authors: Chanalaris A, Clarke H, Guimond SE, Vincent TL, Turnbull JE, Troeberg L Abstract Osteoarthritis (OA) is a common degenerative joint disease, characterized by cartilage loss and subchondral bone remodelling in response to abnormal mechanical load. Heparan sulfate (HS) proteoglycans bind to many proteins that regulate cartilage homeostasis, including growth factors, morphogens, proteases, and their inhibitors, and modulate their localization, retention, and biological activity. Changes in HS expression and structure may thus have important consequences for joint health. We analyzed normal and osteoarthritic human knee cartilage, and found HS biosynthesis was markedly disrupted in OA, with 45% of the 38 genes analyzed differentially regulated in diseased cartilage. The expression of several HS core proteins, biosynthesis, and modification enzymes was increased in OA cartilage, whereas the expression of the HS proteoglycans syndecan 4 and betaglycan was reduced. The structure of HS was also altered, with increased levels of 6-O-sulfation in osteoarthritic samples, which correlated with increased expression of HS6ST1, a 6-O-sulfotransferase, and GLCE, an epimerase that promotes 6-O-sulfation. siRNA silencing of HS6ST1 expression in primary OA chondrocytes inhibited ERK phosphorylation in response to FGF2, showing t...
Source: The American Journal of Pathology - Category: Pathology Authors: Tags: Am J Pathol Source Type: research