RANKL Expression Is Related to the Differentiation State of Human Osteoblasts

• DOI: 10.1359/jbmr.2003.18.6.1088
• Publication Date: 2006-04-26T23:31:38Z
• Authors: Gerald J Atkins; Panagiota Kostakis; Beiqing Pan; Amanda Farrugia; Stan Gronthos; Andreas Evdokiou; Kate Harrison; David M Findlay; Andrew Cw Zannettino
• Keywords: vitamin D3; Transcription, Genetic; Succinimides; Dexamethasone; 03 medical and health sciences; Humans; RNA, Messenger; Vitamin D; Cells, Cultured; Fluorescent Dyes; 0303 health sciences; Membrane Glycoproteins; Osteoblasts; Receptor Activator of Nuclear Factor-kappa B; Reverse Transcriptase Polymerase Chain Reaction; RANK Ligand; RANKL; Glyceraldehyde-3-Phosphate Dehydrogenases; Cell Differentiation; Fluoresceins; Phenotype; Gene Expression Regulation; STRO-1; osteoblast; glucocorticoid; Carrier Proteins; Cell Division

Abstract Human osteoblast phenotypes that support osteoclast differentiation and bone formation are not well characterized. Osteoblast markers were examined in relation to RANKL expression. expression was induced preferentially immature cells. These results an important link between diverse functions. Cells of the lineage two apparently distinct functions: promotion formation. The aim this study examine relationship these human osteoblasts (NHBC), terms pre-osteoblast marker, STRO-1, mature alkaline phosphatase (AP), genes involved formation, OPG. osteotropic stimuli, 1α,25(OH)2vitamin D3 (vitD3) dexamethasone, found have profound proliferative phenotypic effects on NHBCs. VitD3 inhibited NHBC proliferation increased percentage cells expressing STRO-1 over extended culture period, implying vitD3 promotes maintains osteogenic phenotype. Concomitantly, mRNA upregulated maintained response vitD3. Dexamethasone progressively promoted AP-expressing cells, resulting overall maturation cultures. had little effect downregulated OPG a donor-dependent manner. Regression analysis showed associated negatively with AP (p < 0.01) vitD3- dexamethasone-treated In contrast, positively STRO-1+ 0.01). NHBCs sorted by FACS based (STRO-1bright STRO-1dim populations), it STRO-1bright suggest respond factors potentially pro-osteoclastogenic Additionally, dual roles osteoblasts, supporting osteoclastogenesis or forming bone, may be performed same at different stages their maturation.