MODULATION BY HYPERGRAVITY OF EXTRACELLULAR-MATRIX MACROMOLECULES IN IN-VITRO HUMAN DERMAL FIBROBLASTS

Citation
Y. Gaubin et al., MODULATION BY HYPERGRAVITY OF EXTRACELLULAR-MATRIX MACROMOLECULES IN IN-VITRO HUMAN DERMAL FIBROBLASTS, Biochimica et biophysica acta (G). General subjects, 1245(2), 1995, pp. 173-180
Citations number
15
Categorie Soggetti
Biology,Biophysics
ISSN journal
03044165
Volume
1245
Issue
2
Year of publication
1995
Pages
173 - 180
Database
ISI
SICI code
0304-4165(1995)1245:2<173:MBHOEM>2.0.ZU;2-G
Abstract
In vitro human dermal fibroblasts were submitted to normal gravity (1 g) or to chronic hypergravity (20 g) over a period of 8 days. Changes in organization of extracellular matrix molecules were seen by indirec t immunofluorescence. In the fibronectin layer, bundles of fibrils wer e gathered together leading to a disorganisation of the normal paralle l pattern of fibers seen in control cultures. Type I collagen fibrils appeared with wooly outlines in controls whereas thick fibers were clo sely packed in 20-g cultures. A moderate increase of type III collagen fibril density was observed. No elastic fibers were seen in control o r in 20-g cultures. In the culture medium, the release of soluble elas tin (ELISA) and type I and III collagens (RIA) was undisturbed. Assays of enzymes involved in the remodeling of extracellular matrix showed an increase of cellular elastase activity (10%) and a decrease of the spontaneously active collagenase. Nevertheless, the total collagenase activity, (activated by trypsin), was increased by up to 30%. These da ta show a significant rise of the latent collagenase activity and sugg est that release of the tissue inhibitor of metalloproteinase (TIMP1) was enhanced by hypergravity.