Caspases and osteogenic markers--in vitro screening of inhibition impact.

Caspases, well-known players in apoptosis or inflammation, appear to have roles also in other processes such as cell differentiation. Caspase-3, in particular, was recently demonstrated to have non-apoptotic functions in osteogenesis. However, the molecular pathways involved are not yet known. Therefore, we used osteogenic PCR arrays to provide a comprehensive screening of possible interactions of caspases in general and specifically of caspase-3 in osteogenic networks. Embryonic micromass cultures derived from mouse forelimbs were established and pharmacological fluoromethylketone (FMK) inhibitors applied. Alterations were observed in expression of several genes after caspase inhibition (Bmp1, Bmp5, Bmp6, Col10a1, Col2a1, Comp, Egf, Fgfr2, Gli1, Igf1, Nog, Phex, Sox9, Spp1). The list suggests molecular interactions of caspases and osteogenic molecules and creates a background for further temporospatial and functional studies.