Journal of Dental Research, Vol 72, 1473-1480, Copyright © 1993 by International & American Associations for Dental Research Online Journals
Platelet-derived growth factor stimulates hyaluronate but not proteoglycan synthesis by human gingival fibroblasts in vitro
P. M. Bartold
Department of Dentistry, University of Queensland, Brisbane, Australia.
The effect of PDGF-BB on human gingival fibroblasts was monitored in an in
vitro system. PDGF was found to be mitogenic for these cells, although it
required the presence of low concentrations of fetal calf serum to be
active. Proteoglycan and hyaluronate synthesis was analyzed by labeling
newly synthesized macromolecules with [35S]-sulfate or [3H]-glucosamine,
respectively. Identification of specific glycosaminoglycans was achieved by
selective enzymatic or chemical degradations. It was found that cells
cultured in the presence of PDGF showed no discernible differences in
proteoglycan synthesis relative to the control cultures. There were no
alterations in amounts of proteoglycans synthesized, types of sulfated
glycosaminoglycans synthesized, or relative hydrodynamic sizes of the
proteoglycans. In contrast to the proteoglycans, hyaluronate synthesis was
significantly increased in the presence of PDGF. The increase in
[3H]-glucosamine incorporation into newly synthesized hyaluronate
correlated with an increase in the activity of the enzyme hyaluronate
synthetase but could not be accounted for entirely by changes in the
specific activity of sugar nucleotide precursors, which did alter slightly
under differing culture conditions. It is concluded from these results that
PDGF stimulates gingival fibroblasts to proliferate and is associated with
a differential effect of proteoglycan and hyaluronate synthesis. These
observations may correlate with the observed early events associated with
wound healing and repair.
