title: Effects of glutathione depletion on the synthesis of proteoglycan and collagen in cultured chondrocytes.
abstract: We studied the effect of the depletion of glutathione on the synthesis of proteoglycan and collagen in cultured chick chondrocytes. When the cultured chondrocytes were incubated with 1 mM buthionine sulfoximine (BSO), a specific inhibitor of gamma-glutamyl-cysteine synthetase, the intracellular glutathione level markedly dropped within 12 h with no loss of cell viability. Incorporation of 35SO2-4 into proteoglycan was lowered in the presence of BSO. When the 35S-labeled proteoglycans were separated into two fractions by glycerol density gradient centrifugation, the inhibitory effect of BSO on the synthesis of proteoglycan was greater in the fast-sedimenting proteoglycan fraction, which consisted mainly of cartilage specific large proteoglycan (PG-H), than in the slowly sedimenting proteoglycan fraction. The inhibition by BSO of the synthesis of core protein-free glycosaminoglycan chains primed by p-nitrophenyl-beta-D-xyloside was smaller than the inhibition of the synthesis of proteoglycan. Analysis of glycosaminoglycans labeled with [3H]glucosamine indicated that the treatment of chondrocytes with BSO resulted in a small increase in the proportion of synthesis of hyaluronic acid to the synthesis of total glycosaminoglycan. The incorporation of [3H]proline into collagen was also inhibited by BSO. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of the 3H-labeled collagen showed that, in the presence of BSO, processing of Type II collagen appeared to slow down and the proportion of Type X collagen synthesis was reduced.
authors.affiliation: Department of Chemistry, Aichi Kyoiku University, Kariya, Japan.
authors.forename: O
authors.initials: O
authors.lastname: Habuchi
authors.forename: T
authors.initials: T
authors.lastname: Miyachi
authors.forename: S
authors.initials: S
authors.lastname: Kaigawa
authors.forename: S
authors.initials: S
authors.lastname: Nakashima
authors.forename: C
authors.initials: C
authors.lastname: Fujiwara
authors.forename: M
authors.initials: M
authors.lastname: Hisada
mesh_terms: D000818:Animals; D000963:Antimetabolites; D019328:Buthionine Sulfoximine; D002478:Cells, Cultured; D002642:Chick Embryo; D003094:Collagen / Q000096:biosynthesis*; D004591:Electrophoresis, Polyacrylamide Gel; D005944:Glucosamine / Q000378:metabolism; D005978:Glutathione / Q000502:physiology*; D006025:Glycosaminoglycans / Q000378:metabolism; D006027:Glycosides / Q000494:pharmacology; D006132:Growth Plate / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008717:Methionine Sulfoximine / Q000031:analogs & derivatives / Q000494:pharmacology; D009596:Nitrophenols / Q000494:pharmacology; D014176:Protein Biosynthesis; D011499:Protein Processing, Post-Translational; D011509:Proteoglycans / Q000096:biosynthesis*; D013461:Sulfur Oxides / Q000378:metabolism
chemical_list: D000963:Antimetabolites; D006025:Glycosaminoglycans; D006027:Glycosides; D009596:Nitrophenols; D011509:Proteoglycans; D013461:Sulfur Oxides; D008717:Methionine Sulfoximine; C008646:4-nitrophenyl beta-D-xyloside; D019328:Buthionine Sulfoximine; D003094:Collagen; D005978:Glutathione; D005944:Glucosamine