title: A three-dimensional tissue culture model of bone formation utilizing rotational co-culture of human adult osteoblasts and osteoclasts.
abstract: Living bone is a complex, three-dimensional composite material consisting of numerous cell types spatially organized within a mineralized extracellular matrix. To date, mechanistic investigation of the complex cellular level cross-talk between the major bone-forming cells involved in the response of bone to mechanical and biochemical stimuli has been hindered by the lack of a suitable in vitro model that captures the "coupled" nature of this response. Using a novel rotational co-culture approach, we have generated large (>4mm diameter), three-dimensional mineralized tissue constructs from a mixture of normal human primary osteoblast and osteoclast precursor cells without the need for any exogenous osteoconductive scaffolding material that might interfere with such cell-cell interactions. Mature, differentiated bone constructs consist of an outer region inhabited by osteoclasts and osteoblasts and a central region containing osteocytes encased in a self-assembled, porous mineralized extracellular matrix. Bone constructs exhibit morphological, mineral and biochemical features similar to remodeling human trabecular bone, including the expression of mRNA for SOST, BGLAP, ACP5, BMP-2, BMP-4 and BMP-7 within the construct and the secretion of BMP-2 protein into the medium. This "coupled" model of bone formation will allow the future investigation of various stimuli on the process of normal bone formation/remodeling as it relates to the cellular function of osteoblasts, osteoclasts and osteocytes in the generation of human mineralized tissue.
authors.affiliation: Department of Health and Human Performance, University of Houston, Houston, TX 77204, USA. mclarke@central.uh.edu
authors.forename: Mark S F
authors.initials: MS
authors.lastname: Clarke
authors.forename: Alamelu
authors.initials: A
authors.lastname: Sundaresan
authors.forename: Charles R
authors.initials: CR
authors.lastname: Vanderburg
authors.forename: Meredith G
authors.initials: MG
authors.lastname: Banigan
authors.forename: Neal R
authors.initials: NR
authors.lastname: Pellis
mesh_terms: D000328:Adult; D001846:Bone Development / Q000502:physiology*; D002478:Cells, Cultured; D018920:Coculture Techniques / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D040542:Mechanotransduction, Cellular / Q000502:physiology; D010006:Osteoblasts / Q000166:cytology* / Q000502:physiology*; D010010:Osteoclasts / Q000166:cytology* / Q000502:physiology*; D012399:Rotation; D046509:Tissue Culture Techniques / Q000295:instrumentation*; D023822:Tissue Engineering / Q000295:instrumentation*