Journal of Applied Physiology, Vol 63, Issue 6 2181-2188, Copyright © 1987 by American Physiological Society
Effect of subcellular matrix on glycosaminoglycan synthesis by human lung fibroblasts
D. J. Cui, B. A. Dubaybo, R. A. Durr and L. A. Thet
Department of Medicine, Duke University Medical Center, Durham, North Carolina.
The influences modulating glycosaminoglycan production by lung cells are
not well understood. We examined the effect of three different subcellular
matrices, plastic, type I collagen, and reconstituted basement
membrane-like material (RBM), on the synthesis of sulfated
glycosaminoglycans by cultured IMR-90 human lung fibroblasts. Accumulation
of 35SO4-labeled glycosaminoglycans into the cell-matrix layer or medium
was measured. Cells on collagen synthesized significantly less total
glycosaminoglycans than cells on plastic but had a higher fraction of
labeled glycosaminoglycans present in the cell-matrix layer (35 vs. 18%)
with the increases being highest for dermatan and chondroitin sulfates.
Cells grown on the RBM synthesized significantly more glycosaminoglycans
than cells on plastic or collagen and also had 260% more labeled
glycosaminoglycans present in the cell-matrix layer than cells on plastic.
We conclude that the matrix to which lung fibroblasts are exposed can
influence the amount and type of glycosaminoglycans synthesized and the
degree of incorporation into the matrix. This may be relevant to fibrotic
lungs with increased type I collagen or to severely injured lungs in which
intra-alveolar fibroblasts are in contact with denuded basement membranes.
