The in vitro human fracture hematoma model - a tool for preclinical drug testing_suppl

Abstract

blasts (Kolar et al., 2010). Particularly MSCs are considered to play a pivotal role in an adequate healing process, since they are able to differentiate into both chondrocytes and osteoblasts/osteocytes, thereby facilitating bone healing (Knight and Hankenson, 2013). The transcription factor runt-related transcription factor (RUNX2) drives MSCs towards the osteogenic lineage, while its secreted downstream target phosphoprotein 1 (SPP1) is a key marker for early osteogenesis and is also induced by hypoxia-inducible factor 1 (HIF-1; HIF1A) (Gross et al., 2005;Li et al., 2004). Furthermore, matrix metalloproteinase 2 (MMP2) and MMP9, which are fundamental for appropriate bone healing (Henle et al., 2005), are induced via the HIF-1 pathway (Luo et al., 2006;O'Toole et al., 2008).