Synthesis of glycosaminoglycans by human embryonic lung fibroblasts. Different distribution of heparan sulphate, chondroitin sulphate and dermatan sulphate in various fractions of the cell culture

Sjöberg, Ingrid; Fransson, Lars‐Âke

doi:10.1042/bj1670383

Cited by 35 publications

(13 citation statements)

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“…The galactosaminoglycans isolated from the medium and the EDTA extract of lung fibroblasts contained somewhat more IdUA than did corresponding glycans from skin fibroblasts. Moreover, a separate chondroitin sulphate-like glycan appears to be secreted by lung fibroblasts (Sjoberg & Fransson, 1977).…”

Section: Discussionmentioning

confidence: 99%

“…), whereas galactosaminoglycans were the major component of the other fractions. In lung fibroblasts the galactosaminoglycans are composed of one GlcUArich chondroitin sulphate-like component and one IdUA-rich dermatan sulphate component (Sjoberg & Fransson, 1977). The former component was primarily found in the medium, the EDTA extract and the trypsin digest, whereas IdUA-rich glycans were prominent components of the dithiothreitol extract and the insoluble cell fraction.…”

Section: Exchange Experiments With Galactosaminoglycansmentioning

confidence: 99%

“…Distribution of 35S-labelled glycosaminoglycans isolated from various fractions of lung fibroblasts after 12h of 35S042-incorporation The contents of 35S-labelled glycosaminoglycan, 3"S-labelled heparan sulphate and 35S-labelled galactosaminoglycan were determined as described in the Experimental section. The content of GlcUA-rich galactosaminoglycan was calculated from the amounts of disaccharide released by chondroitinase-AC (Sj6berg & Fransson, 1977 (0) and 35S-labelled (-) galactosaminoglycans from the various cell fractions after periodate oxidation/alkaline elimination The 3"S-labelled galactosaminoglycans in (a) were isolated from skin fibroblasts after 48h of labelling and the 3"S-and 3H-labelled galactosaminoglycans in (b) were obtained from lung fibroblasts after 12h of labelling. The galactosaminoglycans were isolated from the insoluble cell residue (C), the dithiothreitol extract (DTT), the trypsin digest (T), the EDTA extract (EDTA) and the medium (M) as described in the Experimental section.…”

Section: Exchange Experiments With Galactosaminoglycansmentioning

confidence: 99%

“…the major portion of heparan sulphate is found in the trypsin-released material, galactosaminoglycans are largely found in the medium (Malmstrom et al, 1975a;Sjoberg & Fransson, 1977). The trypsin digest of lung fibroblasts (Sjoberg & Fransson, 1977) contains heparan sulphate and one GlcUA-rich (chondroitin sulphate-like) and one IdUA-rich and copolymeric galactosaminoglycan (dermatan sulphate).…”

mentioning

confidence: 99%

“…The trypsin digest of lung fibroblasts (Sjoberg & Fransson, 1977) contains heparan sulphate and one GlcUA-rich (chondroitin sulphate-like) and one IdUA-rich and copolymeric galactosaminoglycan (dermatan sulphate). The galactosaminoglycan component of the corresponding fraction from skin fibroblasts (Malmstrom et al, 1975a) is almost exclusively a co-polymeric dermatan sulphate.…”

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confidence: 99%

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Structure and metabolism of sulphated glycosaminoglycans in cultures of human fibroblasts. Structural characteristics of co-polymeric galactosaminoglycans in sequential extracts of fibroblasts during pulse-chase experiments

Sjöberg¹,

Carlstedt²,

Cöster³

et al. 1979

Biochemical Journal

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1. Human embryonic lung and skin fibroblasts were allowed to incorporate glucosamine. After removal of the medium the monolayer was subjected to sequential extractions by using EDTA, brief trypsin digestion, extraction with dithiothreitol followed by freeze-thawing and extraction with trichloroacetic acid. The heparan sulphate and galactosaminoglycan contents of the various extracts were estimated after deaminative cleavage of the former component. Heparan sulphate was the major component of the trypsin digest, whereas galactosaminoglycans were the dominant component of other fractions. 2. Galactosaminoglycans of the various fractions were subjected to chemical (periodate oxidation/alkaline elimination) and enzymic (chondroitinase-AC and -ABC, as well as testicular hyaluronidase) degradations. Galactosaminoglycans from the insoluble cell fraction and the dithiothreitol extract contained larger amounts of L-iduronic acid than did those of other fractions. 3. Pulsechase experiments were performed with and without replating of the cells at the start of the chase period. Radioactive glycans were isolated from the various extracts during the chase period. The half-lives of glycans of the insoluble cell fraction and the dithiothreitol extract were shorter (5-8h) than were those of the trypsin digest and the EDTA extract (22h and 11 h respectively). After replating of the cells in chase medium, radioactive cellassociated glycans were secreted from the cells and could be recovered in the trypsin digest, the EDTA extract and the medium. Furthermore, 35S/3H ratios of glycans from all these fractions decreased during the chase period. The following conclusions were reached. The insoluble cell fraction contains the synthesis pool and some structural material, whereas the soluble cell fraction is the storage and degradation pool. The dithiothreitol extract appears to contain the immediate precursors of secreted material. The trypsin-released glycans comprise structural components as well as material destined for pinocytosis or secretion into the medium. The EDTA extract is considered to consist of glycans en route to the medium. 4. The two presumptive precursor pools were preferentially depleted of L-iduronic acid-rich galactosaminoglycans during the chase. Glycans recovered from the trypsin digest, the EDTA extract and the medium during the chase contained larger amounts of periodate-resistant uronic acid residues (D-glucuronic acid and/or L-iduronic acid 0-sulphate) than did their precursors. It is proposed that polymerlevel modifications of secreted glycans are partly responsible for the results.

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Section: Discussionmentioning

confidence: 99%

Section: Exchange Experiments With Galactosaminoglycansmentioning

confidence: 99%

Section: Exchange Experiments With Galactosaminoglycansmentioning

confidence: 99%

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