title: Regulation of the chondroitin/dermatan fine structure by transforming growth factor-beta1 through effects on polymer-modifying enzymes.
abstract: The chondroitin/dermatan sulfate proteoglycans (CS/DSPGs), biglycan, decorin, and versican play several important roles in extracellular matrix influencing matrix organization, cell proliferation, and recruitment. Moreover, they bind and regulate growth factors in the extracellular matrix. We have previously shown that cultured human lung fibroblasts treated with transforming growth factor-beta (TGF-beta) alone or in combination with epidermal growth factor and platelet-derived growth factor, increase the production of these PGs. In this report, we describe that the structure of their galactosaminoglycan side chains is altered, albeit there is no alteration of polysaccharide length. The findings showed that iduronic acid content is reduced by 50% in decorin and biglycan, whereas 4-O-sulfation is increased 2-fold in versican. To unravel the mechanism behind these changes, the activities of chondroitin C-5 epimerase and of O-sulfotransferases in cellular fractions prepared from fibroblasts were quantitated, and transcript levels of the relevant sulfotransferases were measured by real time polymerase chain reaction (RT-PCR). The C-5 epimerase activity was reduced by 25% in TGF-beta1 treated cells and 50% in fibroblasts treated with the growth factor combination. No change in activity in dermatan 4-O sulfotransferase was observed, and only a minor decrease in dermatan 4-O-sulfotransferase-1 (D4ST-1) mRNA was observed. On the other hand, chondroitin 4-O sulfotransferase activity increased 2-fold upon TGF-beta1 treatment and 3-fold upon treatment with the growth factor combination. This is in agreement with a 2-fold up-regulation of chondroitin-4-O-sulfotransferase 1 (C4ST-1) mRNA, and no changes in chondroitin-4-O-sulfotransferase 2 (C4ST-2) mRNA. Thus, cellular activity and transcript level correlated well with the changes in the structure of the dermatan/chondroitin sulfate chains.
authors.affiliation: Physiological Sciences, Lund University, BMC B11, S-221 84 Lund, Sweden.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Tiedemann
authors.forename: Benny
authors.initials: B
authors.lastname: Olander
authors.forename: Erik
authors.initials: E
authors.lastname: Eklund
authors.forename: Lizbet
authors.initials: L
authors.lastname: Todorova
authors.forename: Martin
authors.initials: M
authors.lastname: Bengtsson
authors.forename: Marco
authors.initials: M
authors.lastname: Maccarana
authors.forename: Gunilla
authors.initials: G
authors.lastname: Westergren-Thorsson
authors.forename: Anders
authors.initials: A
authors.lastname: Malmström
mesh_terms: D002238:Carbohydrate Epimerases / Q000737:chemistry; D002460:Cell Line; D002478:Cells, Cultured; D002807:Chondroitin / Q000737:chemistry*; D002809:Chondroitin Sulfates / Q000737:chemistry; D016207:Cytokines / Q000378:metabolism*; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D058575:Decorin; D003871:Dermatan Sulfate / Q000737:chemistry*; D004187:Disaccharides / Q000737:chemistry; D004815:Epidermal Growth Factor / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000737:chemistry; D005347:Fibroblasts / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D007067:Iduronic Acid / Q000737:chemistry; D008861:Microsomes / Q000378:metabolism; D011108:Polymers / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry; D011509:Proteoglycans / Q000737:chemistry; D012313:RNA / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015238:Sulfotransferases / Q000737:chemistry / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000737:chemistry / Q000378:metabolism*; D053773:Transforming Growth Factor beta1; D015854:Up-Regulation
chemical_list: D016207:Cytokines; C546878:DCN protein, human; D017931:DNA Primers; D018076:DNA, Complementary; D058575:Decorin; D004187:Disaccharides; D016326:Extracellular Matrix Proteins; D011108:Polymers; D011134:Polysaccharides; D011509:Proteoglycans; D012333:RNA, Messenger; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D003871:Dermatan Sulfate; D007067:Iduronic Acid; D004815:Epidermal Growth Factor; D012313:RNA; D002807:Chondroitin; D002809:Chondroitin Sulfates; C007815:galactosaminoglycan; D015238:Sulfotransferases; C438013:dermatan-4-sulfotransferase-1; C019893:chondroitin 4-sulfotransferase; D002238:Carbohydrate Epimerases; C038851:chondroitin D-glucuronosyl 5-epimerase