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rdf:type | |
lifeskim:mentions | |
pubmed:dateCreated |
1993-11-16
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pubmed:abstractText |
During alveolar development and alveolar repair close contacts are established between fibroblasts and lung epithelial cells through gaps in the basement membrane. Using co-culture systems we have investigated whether these close contacts influence synthesis and secretion of the principal surfactant apoprotein (SP-A) by cultured rat lung alveolar type II cells and the synthesis and secretion of type I collagen by fibroblasts. The alveolar type II cells remained cuboidal and grew in colonies on fibroblast feeder layers and on Matrigel-coated cell culture inserts but were progressively more flattened on fixed fibroblast monolayers and plastic. Alveolar type II cells cultured on plastic released almost all their SP-A into the medium by 4 days. Alveolar type II cells cultured on viable fibroblasts or Matrigel-coated inserts above fibroblasts accumulated SP-A in the medium at a constant rate for the first 4 days, and probably recycle SP-A by endocytosis. The amount of mRNA for SP-A was very low after 4 days of culture of alveolar type II cells on plastic, Matrigel-coated inserts or fixed fibroblast monolayers: relatively, the amount of mRNA for SP-A was increased 4-fold after culture of alveolar type II cells on viable fibroblasts. Co-culture of alveolar type II cells with confluent human dermal fibroblasts stimulated by 2- to 3-fold the secretion of collagen type I into the culture medium, even after the fibroblasts' growth had been arrested with mitomycin C. Collagen secretion, by fibroblasts, also was stimulated 2-fold by conditioned medium from alveolar type II cells cultured on Matrigel. The amount of mRNA for type I collagen increased only modestly when fibroblasts were cultured in this conditioned medium. This stimulation of type I collagen secretion diminished as the conditioned medium was diluted out, but at high dilutions further stimulation occurred, indicating that a factor that inhibited collagen secretion also was being diluted out. The conditioned medium contained low levels of IGF-1 and the stimulation of type I collagen secretion was abolished when the conditioned medium was pre-incubated with antibodies to insulin-like growth factor 1 (IGF-1). There are important reciprocal interactions between alveolar type II cells and fibroblasts in co-culture. Direct contacts between alveolar type II cells and fibroblasts appear to have a trophic effect on cultured alveolar type II cells, increasing the levels of mRNA for SP-A. Rat lung alveolar type II cells appear to release a factor (possibly IGF-1) that stimulates type I collagen secretion by fibroblasts.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Apoproteins,
http://linkedlifedata.com/resource/pubmed/chemical/Collagen,
http://linkedlifedata.com/resource/pubmed/chemical/Culture Media, Conditioned,
http://linkedlifedata.com/resource/pubmed/chemical/Culture Media, Serum-Free,
http://linkedlifedata.com/resource/pubmed/chemical/Insulin,
http://linkedlifedata.com/resource/pubmed/chemical/Insulin-Like Growth Factor I,
http://linkedlifedata.com/resource/pubmed/chemical/Mitomycin,
http://linkedlifedata.com/resource/pubmed/chemical/Pulmonary Surfactant-Associated...,
http://linkedlifedata.com/resource/pubmed/chemical/Pulmonary Surfactants,
http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger,
http://linkedlifedata.com/resource/pubmed/chemical/pulmonary surfactant apoprotein
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pubmed:status |
MEDLINE
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pubmed:month |
Jun
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pubmed:issn |
0021-9533
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
105 ( Pt 2)
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
423-32
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pubmed:dateRevised |
2011-11-17
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pubmed:meshHeading |
pubmed-meshheading:8408275-Animals,
pubmed-meshheading:8408275-Apoproteins,
pubmed-meshheading:8408275-Basement Membrane,
pubmed-meshheading:8408275-Cell Communication,
pubmed-meshheading:8408275-Cells, Cultured,
pubmed-meshheading:8408275-Collagen,
pubmed-meshheading:8408275-Culture Media, Conditioned,
pubmed-meshheading:8408275-Culture Media, Serum-Free,
pubmed-meshheading:8408275-Epithelial Cells,
pubmed-meshheading:8408275-Epithelium,
pubmed-meshheading:8408275-Fibroblasts,
pubmed-meshheading:8408275-Gene Expression Regulation,
pubmed-meshheading:8408275-Humans,
pubmed-meshheading:8408275-Insulin,
pubmed-meshheading:8408275-Insulin-Like Growth Factor I,
pubmed-meshheading:8408275-Intercellular Junctions,
pubmed-meshheading:8408275-Mitomycin,
pubmed-meshheading:8408275-Pulmonary Alveoli,
pubmed-meshheading:8408275-Pulmonary Surfactant-Associated Proteins,
pubmed-meshheading:8408275-Pulmonary Surfactants,
pubmed-meshheading:8408275-RNA, Messenger,
pubmed-meshheading:8408275-Rats
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pubmed:year |
1993
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pubmed:articleTitle |
Alveolar type II cell-fibroblast interactions, synthesis and secretion of surfactant and type I collagen.
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pubmed:affiliation |
Department of Biochemistry, Charing Cross and Westminister Medical School, London, UK.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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