Alteration of Proteoglycan Metabolism during the Differentiation of 3T3-L1 Fibroblasts into Adipocytes

• Published in: The Journal of cell biology Vol. 114; no. 4; pp. 821 - 826
• Main Authors: Musil, Kristina J., Malmström, Anders, Donnér, Jakob
• Format: Journal Article
• Language: English
• Published: New York, NY Rockefeller University Press 01.08.1991; The Rockefeller University Press
• Subjects: 1-Methyl-3-isobutylxanthine - pharmacology; 3T3 cells; 3T3 L1 cells; 3T3-L1 adipocytes; Adipocytes; Adipose Tissue - cytology; Adipose Tissue - metabolism; Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Carbohydrates; Cell Differentiation - drug effects; Cell Line; Cell lines; Cells; Cellular differentiation; Chromatography, Ion Exchange; Cultured cells; decorin; Dexamethasone - pharmacology; differentiation; Extracellular matrix; Extracellular Matrix - drug effects; Extracellular Matrix - metabolism; Extracellular Matrix - ultrastructure; Fibroblasts; Fibroblasts - cytology; Fibroblasts - drug effects; Fibroblasts - metabolism; Fundamental and applied biological sciences. Psychology; Heterosides; Hyaluronic Acid - biosynthesis; Hyaluronic Acid - isolation & purification; Insulin - pharmacology; Kinetics; Matematik; Mathematics; matrix proteins; Mice; Natural Sciences; Naturvetenskap; Other biological molecules; Proteoglycans; Proteoglycans - biosynthesis; Proteoglycans - isolation & purification; Proteoglycans - metabolism; Sulfates - metabolism; Sulfur Radioisotopes; Proteoglycan; Adipocyte; Rodentia; 3T3-Cell line; Cell differentiation; Metabolism; Vertebrata; Mammalia; Cell line; Mouse; Extracellular matrix; Biological accumulation; Fibroblast
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.114.4.821

3T3-L1 fibroblasts were induced to differentiate to 3T3-L1 adipocytes by dexamethasone, isobutyl-methylxanthine, and insulin. To study how differentiation affects extracellular matrix production, the accumulation of proteoglycans was studied by labeling the 3T3-L1 cells with [35S]sulphate for 24 h. The labeled proteoglycans were isolated from the medium and cell layer extracts by anion-exchange chromatography. They were then taken to gel filtration chromatography on Superose 6 before or after chondroitin ABC lyase digestion. Hyaluronan was determined by radioimmuno-assay. The rate of accumulation of proteoglycans and hyaluronan in the control 3T3-L1 fibroblasts increased with time whereas it decreased slightly in the age matched adipocytes where the differentiation had proceeded, as judged by the change of morphology and increase of the activity of the adipose conversion markers glycerol-3-phosphate dehydrogenase and hormone sensitive lipase. The main change noted was that the adipocytes accumulated 50-70% less amount of small proteoglycans (decorin) in the medium than the fibroblasts did. The amount of large chondroitin/dermatan sulphate proteoglycans was also decreased but to a considerably smaller extent (30%). In the cell layer, heparan sulphate proteoglycan decreased by 60% as compared with the control cells. Thus, the differentiation of 3T3-L1 fibroblasts into adipocytes, which changes the morphology and the function of the cells, is also accompanied by a decreased net production especially of proteoglycans typical of fibrous connective tissue.