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- Westergren-Thorsson, G, et al.
(författare)
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Altered expression of small proteoglycans, collagen, and transforming growth factor-beta 1 in developing bleomycin-induced pulmonary fibrosis in rats
- 1993
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Ingår i: Journal of Clinical Investigation. - 0021-9738. ; 92:2, s. 7-632
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Tidskriftsartikel (refereegranskat)abstract
- The development of bleomycin-induced pulmonary fibrosis in rats was studied over a period of 21 d after an intratracheal instillation of bleomycin. The expression of three small proteoglycans (biglycan, decorin, and fibromodulin), collagen III and TGF-beta 1 was studied by RNA-transfer blot analysis. The proteoglycans were also studied by SDS-polyacrylamide gel electrophoresis and Western blots. TGF-beta 1 mRNA increased threefold already on day 3 and remained elevated until day 10. After the increase of TGF-beta 1 mRNA the messages for biglycan and collagen III steadily increased to reach a maximum 10 d after bleomycin instillation. The mRNA for biglycan increased maximally fourfold and that of collagen III 2.5-fold. Decorin mRNA, in contrast to biglycan decreased and reached 20% of control on day 10. The message for fibromodulin remained constant throughout the study period. The amounts of biglycan and decorin in the tissue changed in accordance with the mRNA levels. The results corroborate and extend previous in vitro studies concerning the effect of TGF-beta 1 on the metabolism of small proteoglycans and show that these macromolecules are regulated differently also in vivo. The marked alterations of biglycan and decorin during the development of fibrosis suggests that these proteoglycans have a regulating role in this process.
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| 3. |
- Westergren-Thorsson, G, et al.
(författare)
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TGF-beta enhances the production of hyaluronan in human lung but not in skin fibroblasts
- 1990
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Ingår i: Experimental Cell Research. - : Elsevier BV. - 0014-4827. ; 186:1, s. 5-192
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Tidskriftsartikel (refereegranskat)abstract
- Transforming growth factor-beta (TGF-beta) enhances the production of extracellular matrix components, such as type I and type III collagen, fibronectin, proteoglycans, in various cell types. The effect on hyaluronan synthesis in relation to proteoglycan synthesis has not been investigated. Human lung or skin fibroblast cultures were treated with TGF-beta in serum-free medium for various periods of time. 35SO4 or [3H]glucosamine was then added to the cultures in the absence of TGF-beta for up to 48 h. Hyaluronan and proteoglycans were isolated by ion-exchange chromatography and quantitated. TGF-beta induced a three- to fourfold increase in hyaluronan production by lung cells but had no effect on skin fibroblasts. In contrast, proteoglycan synthesis was enhanced in both cell types, although skin fibroblasts responded at lower concentrations of TGF-beta. Increased accumulation of hyaluronan was noted only in the cell medium, whereas proteoglycan accumulation was observed both in the medium and in the cell layer. The ED50 for TGF-beta on hyaluronan accumulation in lung cells was the same as that for proteoglycan accumulation, i.e., 40 pM. In skin fibroblasts the ED50 was considerably lower (4 pM). The induction time needed to attain full effect of TGF-beta was 6 h for both hyaluronan and proteoglycan synthesis. These results indicate that TGF-beta has tissue-specific effects on matrix production which may be of importance for control of cell proliferation in various disease states.
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