Uh. Lerner et al., BACTERIA INHIBIT BIOSYNTHESIS OF BONE-MATRIX PROTEINS IN HUMAN OSTEOBLASTS, Clinical orthopaedics and related research, (346), 1998, pp. 244-254
The effect of extracts from Staphylococcus aureus and Staphylococcus e
pidermidis on bone matrix production were assessed by analyzing the bi
osynthesis of osteocalcin and Type I collagen in a human osteoblastic
osteosarcoma cell line (MG-63). In MG-63 cells, extracts from Staphylo
coccus aureus and Staphylococcus epidermidis decreased 1,25(OH)(2)-vit
amin D-3 stimulated osteocalcin biosynthesis, and insulinlike growth f
actor I induced production of Type I collagen in a concentration depen
dent manner, The basal rate of osteocalcin and Type I collagen formati
on was unaffected by the bacterial extracts, The inhibitory effect of
the bacteria on osteocalcin biosynthesis was seen after 24 hours of tr
eatment and was maintained for at least 96 hours, The extracts of Stap
hylococcus aureus and Staphylococcus epidermidis enhanced prostaglandi
n E-2 formation in the MG-63 cells, Abolition of the prostaglandin E-2
response by treatment with indomethacin and flurbiprofen did not affe
ct bacteria induced inhibition of osteocalcin production, Stimulation
of osteocalcin biosynthesis by 1,25(OH)(2)-vitamin D-3 was associated
with a decreased rate of cell proliferation, The inhibitory action of
the bacterial extracts was not linked to any inhibition of [H-3]-thymi
dine incorporation into deoxyribonucleic acid, These data show that ex
tracts of Staphylococcus aureus and Staphylococcus epidermidis have th
e ability to inhibit the biosynthesis of bone matrix proteins by a non
prostaglandin and noncytotoxic dependent mechanism and suggest that bo
ne loss in inflammatory processes containing Staphylococcus aureus or
Staphylococcus epidermidis may not be caused only by enhanced bone res
orption but also by decreased bone formation.