title: Human stem cell osteoblastogenesis mediated by novel glycogen synthase kinase 3 inhibitors induces bone formation and a unique bone turnover biomarker profile in rats.
abstract: Wnt activation by inhibiting glycogen synthase kinase 3 (GSK-3) causes bone anabolism in rodents making GSK-3 a potential therapeutic target for osteoporotic and osteolytic metastatic bone disease. To understand the wnt pathway related to human disease translation, the ability of 3 potent inhibitors of GSK-3 (AZD2858, AR79, AZ13282107) to 1) drive osteoblast differentiation and mineralisation using human adipose-derived stem cells (hADSC) in vitro; and 2) stimulate rat bone formation in vivo was investigated. Bone anabolism/resorption was determined using clinically relevant serum biomarkers as indicators of bone turnover and bone formation assessed in femurs by histopathology and pQCT/μCT imaging. GSK-3 inhibitors caused β-catenin stabilisation in human and rat mesenchymal stem cells, stimulated hADSC commitment towards osteoblasts and osteogenic mineralisation in vitro. AZD2858 produced time-dependent changes in serum bone turnover biomarkers and increased bone mass over 28 days exposure in rats. After 7 days, AZD2858, AR79 or AZ13282107 exposure increased the bone formation biomarker P1NP, and reduced the resorption biomarker TRAcP-5b, indicating increased bone anabolism and reduced resorption in rats. This biomarker profile was differentiated from anabolic agent PTH1-34 or the anti-resorptive Alendronate-induced changes. Increased bone formation in cortical and cancellous bone as assessed by femur histopathology supported biomarker changes. 14 day AR79 treatment increased bone mineral density and trabecular thickness, and decreased trabecular number and connectivity assessed by pQCT/μCT. GSK-3 inhibition caused hADSC osteoblastogenesis and mineralisation in vitro. Increased femur bone mass associated with changes in bone turnover biomarkers confirmed in vivo bone formation and indicated uncoupling of bone formation and resorption.
authors.affiliation: New Opportunities Innovative Medicines group, AstraZeneca R&D, Alderley Park, Cheshire SK10 4TF, UK. Electronic address: Peter.Gilmour@astrazeneca.com.
authors.forename: Peter S
authors.initials: PS
authors.lastname: Gilmour
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: O'Shea
authors.forename: Malbinder
authors.initials: M
authors.lastname: Fagura
authors.forename: James E
authors.initials: JE
authors.lastname: Pilling
authors.forename: Hitesh
authors.initials: H
authors.lastname: Sanganee
authors.forename: Hiroki
authors.initials: H
authors.lastname: Wada
authors.forename: Paul F
authors.initials: PF
authors.lastname: Courtney
authors.forename: Stefan
authors.initials: S
authors.lastname: Kavanagh
authors.forename: Peter A
authors.initials: PA
authors.lastname: Hall
authors.forename: K Jane
authors.initials: KJ
authors.lastname: Escott
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000187:drug effects; D016723:Bone Remodeling / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D005260:Female; D005269:Femur / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors*; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D015394:Molecular Structure; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D010012:Osteogenesis / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D015415:Biomarkers; D004791:Enzyme Inhibitors; D038362:Glycogen Synthase Kinase 3
keywords: Biomarkers; Bone turnover; In vivo; Stromal/stem cells; Wnt; β-catenin