title: Local osteogenic expression of cyclooxygenase-2 and systemic response in porcine models of osteomyelitis.
abstract: It is suggested that cyclooxygenase 2 (COX-2) derived prostaglandins contributes to the progressive bone loss seen in osteomyelitis lesions. In the present study we examined the expression of COX-2 in bones from 23 pigs with experimental osteomyelitis. Osteomyelitis was induced with Staphylococcus aureus and groups of animals were euthanized following 6 h, 12 h, 24 h, 2 days, 5 days, 11 days and 15 days, respectively. Expression of COX-2 was evaluated immunohistochemically and combined with characterization of morphological changes in bone tissue. Furthermore, the serum concentrations of alkaline phosphatase and haptoglobin were measured. Extensive COX-2 expression by osteoblasts was present 2 days after inoculation together with many activated osteoclasts. Simultaneously, the serum concentration of alkaline phosphatase decreased whereas the haptoglobin concentration increased. This is the first in vivo study showing an early wave of COX-2 mediated bone resorption during osteomyelitis. Therefore, treatment aiming to reduce the break down of bone tissue directed by the COX-2 pathway might be suggested early in the course of the disease.
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Life Sciences, Copenhagen University, Ridebanevej 3, 1870 Frederiksberg C, Denmark. louise-k@life.ku.dk
authors.forename: Louise K
authors.initials: LK
authors.lastname: Johansen
authors.forename: Tine M
authors.initials: TM
authors.lastname: Iburg
authors.forename: Ole L
authors.initials: OL
authors.lastname: Nielsen
authors.forename: Páll S
authors.initials: PS
authors.lastname: Leifsson
authors.forename: Kirstin
authors.initials: K
authors.lastname: Dahl-Petersen
authors.forename: Janne
authors.initials: J
authors.lastname: Koch
authors.forename: Dorte
authors.initials: D
authors.lastname: Frees
authors.forename: Bent
authors.initials: B
authors.lastname: Aalbæk
authors.forename: Peter M H
authors.initials: PM
authors.lastname: Heegaard
authors.forename: Henrik E
authors.initials: HE
authors.lastname: Jensen
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D017886:Durapatite / Q000378:metabolism*; D006242:Haptoglobins / Q000378:metabolism; D007150:Immunohistochemistry; D023421:Models, Animal; D010006:Osteoblasts / Q000378:metabolism; D010019:Osteomyelitis / Q000378:metabolism*; D013203:Staphylococcal Infections / Q000378:metabolism; D013552:Swine
chemical_list: D006242:Haptoglobins; D017886:Durapatite; D051546:Cyclooxygenase 2; D000469:Alkaline Phosphatase