Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5 Pt 1
pubmed:dateCreated
1992-6-25
pubmed:abstractText
Both type I and type II pulmonary epithelial cells contact the extracellular matrix (ECM). Type II cell-ECM interactions are bidirectional; they involve matrix-mediated modulation of type II cell differentiation, as well as cellular synthesis and deposition of ECM components. The present experiments examine the kinetics of accumulation of newly synthesized proteins in cell and matrix fractions from primary cultures of type II pneumocytes. Cycloheximide-sensitive incorporation of [3H]leucine into total protein of both the cell and ECM fractions was linear for 24-30 h, when steady-state labeling was reached and maintained to at least day 8. Over this interval, the cells enlarged but did not divide. Newly synthesized proteins recovered in the matrix fraction averaged 1-2% of those in the cells. Relative rates of radiolabeling of matrix proteins peaked at culture day 2 and increased in the absence of serum. In short-pulse studies, initial rates of protein synthesis were equal on culture days 1 and 3; this suggested that the steady-state labeling kinetics above reflected protein turnover. This was supported by rapid loss of radioactivity from the ECM after fresh type II cells were seeded on a prelabeled, cell-free matrix surface. Fresh or conditioned Dulbecco's modified Eagle's medium containing 10% fetal calf serum had little effect on matrix stability. These results demonstrate regulated deposition and turnover of a complex ECM by type II cells and provide a basis for further investigations of factors that control these processes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
262
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
L582-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Extracellular matrix synthesis and turnover by type II pulmonary epithelial cells.
pubmed:affiliation
Department of Cellular and Molecular Physiology, College of Medicine, Pennsylvania State University, Hershey 17033.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.