The lack of effect of glucosamine sulphate on aggrecan mRNA expression and (35)S-sulphate incorporation in bovine primary chondrocytes.
Glucosamine and glucosamine sulphate have been promoted as a disease-modifying agent to improve the clinical symptoms of osteoarthritis. The precise mechanism of the action of the suggested positive effect of glucosamine or glucosamine sulphate on cartilage proteoglycans is not known, since the level of glucosamine in plasma remains very low after oral administration of glucosamine sulphate. We examined whether exogenous hexosamines or their sulphated forms would increase steady-state levels of aggrecan and hyaluronan synthase (HAS) or glycosaminoglycan synthesis using Northern blot and (35)S-sulphate incorporation analyses. Total RNA was extracted from bovine primary chondrocytes which were cultured either in 1 mM concentration of glucosamine, galactosamine, mannosamine, glucosamine 3-sulphate, glucosamine 6-sulphate or galactosamine 6-sulphate for 0, 4, 8 and 24 h, or in three different concentrations (control, 100 microM and 1 mM) of glucosamine sulphate salt or glucose for 24 or 72 h. Northern blot assay showed that neither hexosamines nor glucosamine sulphate salt stimulated aggrecan and HAS-2 mRNA expression. Glycosaminoglycan synthesis remained at a control level in the treated cultures, with the exception of mannosamine which inhibited (35)S-sulphate incorporation in low-glucose DMEM treatment. In our culture conditions, hexosamines or their sulphated forms did not increase aggrecan expression or (35)S-sulphate incorporation.
Qu
Cheng-Juan
CJ
Department of Anatomy, Institute of Biomedicine, University of Kuopio, PO Box 1627, 70211 Kuopio, Finland.
Karjalainen
Hannu M
HM
Helminen
Heikki J
HJ
Lammi
Mikko J
MJ
D053674:Aggrecans; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism*; D011508:Chondroitin Sulfate Proteoglycans / Q000096:biosynthesis* / Q000235:genetics; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis* / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D005944:Glucosamine / Q000494:pharmacology*; D014453:Glucuronosyltransferase / Q000096:biosynthesis; D006025:Glycosaminoglycans / Q000096:biosynthesis; D006595:Hexosamines / Q000494:pharmacology; D000076002:Hyaluronan Synthases; D037181:Lectins, C-Type / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis*; D013462:Sulfur Radioisotopes
D053674:Aggrecans; D011508:Chondroitin Sulfate Proteoglycans; D016326:Extracellular Matrix Proteins; D006025:Glycosaminoglycans; D006595:Hexosamines; D037181:Lectins, C-Type; D012333:RNA, Messenger; D013462:Sulfur Radioisotopes; D014453:Glucuronosyltransferase; D000076002:Hyaluronan Synthases; D005944:Glucosamine