Osteoblast and Osteoclast Differentiation in anIn VitroThree-Dimensional Model of Bone

Abstract

There is increasing interest in developing new in vitro tissue models using typical tissue engineering approaches. This study was designed to (1) develop a novel three-dimensional (3D) in vitro model of bone by seeding murine primary osteoblasts and osteoclast precursors on a resorbable porous ceramic scaffold based on silicon-stabilized tricalcium phosphate (Skelite), and (2) investigate bone cell interactions in a 3D environment mimicking an in vivo condition and compare it to traditional two-dimensional (2D) cultures. Murine primary osteoblasts from C57Bl6/J mice and osteoclast precursors from C57Bl/6-Tg(ACTB-EGFP)1Osb/J mice were co-cultured on 3D Skelite scaffolds and on standard plastic culture dishes. The differentiation of these cells in both culture conditions was compared by histology (hematoxylin-eosin staining and polarized light analysis), immunohistochemistry (collagen type I), and gene expression analysis by real-time PCR for Runt-related transcription factor 2, osterix, osteocalcin, cathepsin K, and tartrate resistant acid phosphatase. To analyze and compare bone turnover in 3D and 2D co-cultures, we evaluated the modulation of RANKL and OPG mRNA expression. We observed an enhancement of osteoblast differentiation in the 3D mineralized environment that in turn promoted earlier osteoclast differentiation. In this paper, we also report that the increased osteoblast differentiation in the 3D model led to a deposition of extracellular matrix that faithfully reflected the morphology of bone tissue.

Development of an osteoblast/osteoclast co-culture derived by human bone marrow stromal cells and human monocytes for biomaterials testing

“…Some authors report on successful cultures of osteoblast cell lines or primary osteoblasts in combination with PBMC or isolated monocytes. The cells were of murine or human origin and were cultivated with or without the addition of M-CSF and RANKL (Bloemen et al, 2009;Greiner et al, 2009;Jones et al, 2009;Tortelli et al, 2009;Bernhardt et al, 2010). Only few publications dealing with co-cultures based on BMSC are known.…”

hRpn13, a newly identified component of the 19S particle, regulates proliferation, differentiation, and function in the human osteoblast-like cell line MG63

“…Osteoblasts also regulate the growth of osteoclasts by secreting OPG, a decoy receptor for RANKL and therefore a competitor of RANK, to restrain the activity of the RANKL-RANK system [4]. Thus, the ratio of RANKL to OPG dictate the activity of osteoclasts, the resorption of bone [1,24]. Along this line, a recent study demonstrated that knockdown of hRpn13 expression decreased the total number of osteoclasts [18].…”

“…Adult bone is renewed and remodeled through coordinated processes regulated by osteoblasts and osteoclasts [24], which are in turn mediated by the ubiquitin-proteasome system. Osteoclasts resorb bones, whereas osteoblasts form new bones at the same site.…”

In vitro osteoclastogenesis on textile chitosan scaffold

“…However these authors also report a discontinuity of the resorption pattern, which might be caused by the complex three-dimensional structure of the material. The differentiation of murine osteoclast precursors in a porous silicon-stabilized ceramic was investigated by Tortelli et al in co-culture using murine osteoblasts (Tortelli et al, 2009). Gene expression of osteoclastic markers TRAP and cathepsin K was lower for cells cultured in the porous ceramic compared to the control on polystyrene surfaces.…”