A 300 μm Organotypic Bone Slice Culture Model for Temporal Investigation of Endochondral Osteogenesis.

Translational studies to elucidate the response of immature bone to biologic and physical stimuli have been held back by the lack of a viable long-term functional bone explant model. This study attempts to bridge this gap between cell culture and animal model studies. In this study, we describe a methodology to derive a 300 μm organotypic femur slice comprising physiological zones (epiphysis and meta-diaphysis) essential for endochondral bone development.

Runx2 mediated Induction of Novel Targets ST2 and Runx3 Leads to Cooperative Regulation of Hypertrophic Differentiation in ATDC5 Chondrocytes.

Knowledge concerning expression and function of Suppression of Tumorigenicity 2 (ST2) in chondrocytes is at present, limited. Analysis of murine growth plates and ATDC5 chondrocytes indicated peak expression of the ST2 transmembrane receptor (ST2L) and soluble (sST2) isoforms during the hypertrophic differentiation concomitant with the expression of the hypertrophic markers Collagen X (Col X), Runx2 and MMP-13. Gain- and loss-of-function experiments in ATDC5 and primary human growth plate chondrocytes (PHCs), confirmed regulation of ST2 by the key transcription factor Runx2, indicating ST2 to be a novel Runx2 target.