title: Piroxicam treatment augments bone abnormalities in interleukin-10 knockout mice.
abstract: BACKGROUND
  Osteoporosis and fractures are common complications of inflammatory bowel disease. The pathogenesis is multifactorial and has been partly attributed to intestinal inflammation. The aim of this study was to evaluate bone status and assess the association between bone loss and gut inflammation in an experimental colitis model.
  
  
  METHODS
  Colitis was induced in interleukin-10 knockout mice (PAC IL-10 k.o.) by peroral administration of piroxicam for 12 days. The degree of colitis was assessed by clinical, macroscopic, and microscopic evaluation. Trabecular and cortical bone microarchitecture of tibia were determined using micro-computed tomography. Moreover, the serum levels of bone formation and bone resorption biomarkers were measured, and inflammatory protein profiling was performed on colons.
  
  
  RESULTS
  PAC IL-10 k.o. mice developed severe colitis, characterized by hyperplasia and focal transmural inflammation, which was consistent with Crohn's disease-like pathology. The gut inflammation was accompanied by a 14% and 12% reduction in trabecular thickness relative to piroxicam-treated wild type and untreated wild type mice, respectively (P < 0.001). The trabecular bone structure was also changed in PAC IL-10 k.o. mice, whereas no differences in cortical bone geometry were observed. The trabecular thickness was inversely correlated with serum levels of CTX (r = -0.93, P = 0.006). Moreover, numerous inflammatory mediators, including RANKL and osteoprotegerin, were significantly increased in the colon of PAC IL-10 k.o. mice.
  
  
  CONCLUSIONS
  PAC IL-10 k.o. mice develop bone loss and changed trabecular structure, as a result of increased bone resorption. Thus, the PAC IL-10 k.o. model could be a useful experimental model in preclinical research of inflammatory bowel disease-associated bone loss.
authors.affiliation: *Novo Nordisk-LIFE In Vivo Pharmacology Centre, Frederiksberg, Denmark; †Developmental Endocrinology Research Group, School of Medicine, Royal Hospital for Sick Children, University of Glasgow, Glasgow, United Kingdom; ‡Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark; §Division of Developmental Biology, The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom; ‖Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom; and ¶Department of Immunopharmacology, Novo Nordisk A/S, Maaloev, Denmark.
authors.forename: Kristine
authors.initials: K
authors.lastname: Holgersen
authors.forename: Ross
authors.initials: R
authors.lastname: Dobie
authors.forename: Colin
authors.initials: C
authors.lastname: Farquharson
authors.forename: Rob
authors.initials: R
authors.lastname: vanʼt Hof
authors.forename: Syed Faisal
authors.initials: SF
authors.lastname: Ahmed
authors.forename: Axel Kornerup
authors.initials: AK
authors.lastname: Hansen
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Holm
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000633:toxicity*; D015519:Bone Density / Q000187:drug effects; D001851:Bone Diseases, Metabolic / Q000209:etiology* / Q000473:pathology; D003092:Colitis / Q000139:chemically induced / Q000276:immunology / Q000473:pathology*; D004195:Disease Models, Animal; D005260:Female; D007249:Inflammation / Q000209:etiology* / Q000473:pathology; D016753:Interleukin-10 / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010024:Osteoporosis / Q000209:etiology* / Q000473:pathology; D010894:Piroxicam / Q000633:toxicity*; D055114:X-Ray Microtomography
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D016753:Interleukin-10; D010894:Piroxicam