Abstract

A basic requirement for bone remodeling is the communication between bone forming osteoblasts and bone resorbing osteoclasts – the so-called cross talk. Corresponding in vitro co-culture models might be a valuable technique in order to investigate the influence of novel biomaterials on the cross talk. Assuming that both cell types are derived by precursor cells, the role of the common osteogenic supplements concerning the osteoclastogenesis is still little known. Therefore, the approach of the present study was to analyse osteoclast formation in the presence of both, osteoclast differentiation factors as well as osteogenic differentiation factors dexamethasone (Dex), β-glycerophosphate (β-GP) and 1.25-dihydroxy vitamin D3 (VitD3) in typical concentration ranges as used for osteoblastogenesis of bone marrow stromal cells (BMSC). Human monocytes were isolated from buffy coat and separated by using magnetic activated cell sorting (MACS). DNA amount, activity of tartrate-resistant acid phosphatase isoform 5b (TRAP 5b), morphological features of the cells as well as gene expression for TRAP, cathepsin K (CTSK), calcitonin receptor (CALCR) and vitronectin receptor (VTNR) were evaluated. Finally, we are able to suggest conditions which allow both, osteoblastogenesis and osteoclastogenesis of human precursor cells in a combined cultivation medium.

Key words: Human bone marrow stromal cell, human monocytes, osteoclasts, osteoclastogenesis, osteogenic supplement, co-culture.