Journal of Dental Research, Vol 66, 1449-1455, Copyright © 1987 by International & American Associations for Dental Research Online Journals
Bacterial endotoxin inhibits migration, attachment, and orientation of human gingival fibroblasts in vitro and delays collagen gel contraction
S. Pitaru, M. Soldinger, D. Madgar and Z. Metzger
The purpose of this study was to assess the effect of endotoxin adsorbed to
dental surfaces and to collagen type I on the migration, attachment, and
orientation of human gingival fibroblasts (HGF). Transversely cut porcine
tooth root slices (RS), 200 micron thick, were prepared. Half of the RS
obtained were partially demineralized in EDTA. Half of the demineralized
and non-demineralized RS were incubated with 400 micrograms/mL of endotoxin
for 24 hr, whereas the other half were maintained in PBS and served as
controls. Experimental and control RS were placed on confluent layers of
HFG and cultured for six days. Cell migration toward and cell attachment to
the periphery of the RS and the formation of oriented cell sheets were
assessed by means of photographic techniques. Additionally, six-day-old
cultures were fixed and processed for SEM observation. In separate
experiments, the effect of endotoxin on cell attachment to collagen type I
and on contraction of three-dimensional collagen gels was assessed. It was
found that: (i) bacterial endotoxin inhibited migration and attachment of
HGF to both demineralized and non-demineralized cementum and interfered
with the development of oriented cellular structure: (ii) the inhibitory
effect was significantly more pronounced for non-demineralized than for
demineralized cementum: (iii) the morphology of HGF attached to
endotoxin-treated dental surfaces was altered compared with that of their
controls: and (iv) bacterial endotoxin inhibited cell attachment to
collagen type I and delayed the contraction of collagen gel.
