Mason, Deborah Jane ORCID: https://orcid.org/0000-0002-8666-6094, Dillingham, Christopher Mark ORCID: https://orcid.org/0000-0003-2315-6158, Williams, S. E., Evans, Bronwen Alice James ORCID: https://orcid.org/0000-0002-3082-1008, Brakspear, Karen Sarah and Ralphs, Jim 2009. Interactions between osteocytes and osteoblasts in a novel 3D co-culture system [Abstract]. International Journal of Experimental Pathology 90 (2) , A104. 10.1111/j.1365-2613.2008.00644.x |
Abstract
Introduction Osteocytes, the most abundant bone cell type, form an intercommunicating network within bone integrating hormonal, growth factor and mechanical stimuli to control osteoblast activity. The importance of this osteocyte-driven control is exemplified by human disorders where mutations in the osteocyte-derived protein sclerostin cause excessive bone mass. We have devised a co-culture system to investigate osteocyte/osteoblast interactions. Materials and Methods Osteocyte cell lines (MLO-Y4, MLOA5) were embedded within type I collagen gels with osteoblast cell lines (MG63/SaOS2) layered on top. Cell phenotypes were visually assessed by light microscopy, immunolocalisation and fluorescence microscopy. Gene expression was quantified by real time RT-PCR of RNA extracted separately from surface cells and gel-embedded cells within the same cocultures. Results Osteocytes formed a network of dendritic cells, maintained for at least 2 weeks, with extensive processes connecting neighbouring osteocytes and extending towards osteoblasts on the gel surface. Comparison of osteoblasts cultured on empty gels and those co-cultured with osteocytes revealed that osteocytes inhibit both invasion into the gel and expression of Type I collagen by osteoblasts. The osteocyte dendritic marker E11 was expressed by MLO-Y4 osteocytes. E11 was not expressed by MG63 osteoblasts on the surface of osteocyte-filled gels, but was expressed when MG63s were incorporated within the gel. Human primary osteoblasts embedded within collagen gels assume a dendritic morphology, downregulate Runx2 and upregulate osteocalcin mRNA expression, indicative of differentiation to an osteocyte-like phenotype. Discussion Osteocytes regulate osteoblast functions in this co-culture model and embedding osteoblasts within type I collagen induces differentiation to an osteocyte-like cell.
Item Type: | Article |
---|---|
Date Type: | Publication |
Status: | Published |
Schools: | Biosciences |
Publisher: | Wiley-Blackwell |
ISSN: | 0959-9673 |
Last Modified: | 02 Dec 2022 11:53 |
URI: | https://orca.cardiff.ac.uk/id/eprint/8947 |
Citation Data
Actions (repository staff only)
Edit Item |