Comparison of the osteolytic activity of surface-associated proteins of bacteria implicated in periodontal disease.
OBJECTIVE
To compare the osteolytic activity of surface-associated material (SAM) and lipid A-associated proteins (LAPs) from periodontopathogenic bacteria.


METHODS
Surface-associated material was extracted from the surface and LAPs from the cell walls of a range of periodontopathic bacteria including Actinobacillus actinomycetemcomitans and Eikenella corrodens. These bacterial fractions were assayed to determine their composition and their capacity to induce bone resorption was determined by use of the neonatal murine calvarial bone resorption assay.


RESULTS
The SAMs from E. corrodens and A. actinomycetemcomitans demonstrated bone-resorbing capacity at concentrations as low as 1 ng ml-1 which, given the molecular weights of the active components, is in the picomolar range of activity. In contrast, the SAMs from the other three bacteria were significantly less potent and showed a lower efficacy. The LAPs all showed significant, and similar, capacities to induce bone breakdown.


CONCLUSIONS
This is the first demonstration that LAP from periodontopathic bacteria can stimulate bone degradation. The LAPs from diverse bacteria all produced similar levels of bone-resorbing activity. In contrast, the SAM showed significant differences in potency and in efficacy (maximal stimulation). This may mean that in vivo certain periodontopathic bacteria have significantly more bone-resorbing capacity than others and should be therapeutic targets.
Reddi
K
K
Maxillofacial Surgery Research Unit, Eastman Dental Institute for Oral Health Care Sciences, University of London, United Kingdom.
Meghji
S
S
Wilson
M
M
Henderson
B
B
D016976:Aggregatibacter actinomycetemcomitans / Q000737:chemistry / Q000472:pathogenicity / Q000502:physiology; D016301:Alveolar Bone Loss / Q000382:microbiology*; D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000502:physiology*; D001426:Bacterial Proteins / Q000502:physiology; D002167:Campylobacter / Q000737:chemistry / Q000472:pathogenicity / Q000502:physiology; D016124:Eikenella corrodens / Q000737:chemistry / Q000472:pathogenicity / Q000502:physiology; D004731:Endotoxins / Q000032:analysis / Q000502:physiology; D010861:Fimbriae, Bacterial / Q000737:chemistry; D006089:Gram-Negative Anaerobic Bacteria / Q000737:chemistry / Q000472:pathogenicity* / Q000502:physiology; D008050:Lipid A / Q000502:physiology; D051379:Mice; D010014:Osteolysis / Q000139:chemically induced / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000737:chemistry / Q000472:pathogenicity / Q000502:physiology
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004731:Endotoxins; D008050:Lipid A; C027315:lipid A-associated protein, Bacteria