title: 3D mesenchymal stem/stromal cell osteogenesis and autocrine signalling.
abstract: Mesenchymal stem/stromal cells (MSC) are rapidly becoming a leading candidate for use in tissue regeneration, with first generation of therapies being approved for use in orthopaedic repair applications. Capturing the full potential of MSC will likely require the development of novel in vitro culture techniques and devices. Herein we describe the development of a straightforward surface modification of an existing commercial product to enable the efficient study of three dimensional (3D) human bone marrow-derived MSC osteogenic differentiation. Hundreds of 3D microaggregates, of either 42 or 168 cells each, were cultured in osteogenic induction medium and their differentiation was compared with that occurring in traditional two dimensional (2D) monolayer cultures. Osteogenic gene expression and matrix composition was significantly enhanced in the 3D microaggregate cultures. Additionally, BMP-2 gene expression was significantly up-regulated in 3D cultures at day 3 and 7 by approximately 25- and 30-fold, respectively. The difference in BMP-2 gene expression between 2D and 3D cultures was negligible in the more mature day 14 osteogenic cultures. These data support the notion that BMP-2 autocrine signalling is up-regulated in 3D MSC cultures, enhancing osteogenic differentiation. This study provides both mechanistic insight into MSC differentiation, as well as a platform for the efficient generation of microtissue units for further investigation or use in tissue engineering applications.
authors.affiliation: Stem Cell Therapies Laboratory, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Qld., Australia.
authors.forename: Mahboubeh
authors.initials: M
authors.lastname: Kabiri
authors.forename: Betul
authors.initials: B
authors.lastname: Kul
authors.forename: William B
authors.initials: WB
authors.lastname: Lott
authors.forename: Kathryn
authors.initials: K
authors.lastname: Futrega
authors.forename: Parisa
authors.initials: P
authors.lastname: Ghanavi
authors.forename: Zee
authors.initials: Z
authors.lastname: Upton
authors.forename: Michael R
authors.initials: MR
authors.lastname: Doran
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D019898:Autocrine Communication / Q000235:genetics; D055396:Bone Morphogenetic Protein 2 / Q000235:genetics / Q000378:metabolism; D001861:Bone Regeneration; D002113:Calcification, Physiologic / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000378:metabolism / Q000502:physiology*; D010012:Osteogenesis / Q000235:genetics
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D000469:Alkaline Phosphatase