Conditioned medium from fresh and demineralized bone enhances osteoclastogenesis in XXXX bone marrow cultures.

@entity5272 @entity9827 @entity19 @entity641 @entity1072 @entity5271 @entity17058 @entity27948 @entity9830 @entity21795
OBJECTIVES: Osteoclasts rapidly form on the surface of bone chips at augmentation sites. The underlying molecular mechanism, however, is unclear. Soluble factors released from bone chips in  vitro have a robust impact on mesenchymal cell differentiation. Whether these soluble factors change the differentiation of hematopoietic cells into osteoclasts remains unknown. METHODS: Osteoclastogenesis, the formation of @entity5272 -resistant acid phosphatase-positive multinucleated cells, was studied with @entity19 bone marrow cultures exposed to @entity5271 and @entity9827 , and conditioned medium from fresh ( @entity27948 ) and demineralized bone matrix (DCM). Histochemical staining, gene and protein expression, as well as viability assays were performed. RESULTS: This study shows that @entity27948 had no impact on osteoclastogenesis. However, when @entity27948 was heated to 85  C (BCMh), the number of @entity5272 -resistant acid phosphatase-positive multinucleated cells that developed in the presence of @entity5271 and @entity9827 approximately doubled. In line with the histochemical observations, there was a trend that BCMh increased expression of osteoclast marker genes, in particular the transcription factor @entity9830 . The expression of @entity9830 was significantly reduced by the @entity641 receptor I antagonist @entity21795 . @entity17058 significantly stimulated osteoclastogenesis, independent of thermal processing. CONCLUSIONS: These data demonstrate that activated @entity27948 by heat and @entity1072 are able to stimulate osteoclastogenesis in  vitro. These in  vitro results support the notion that the resorption of autografts may be supported by as yet less defined paracrine mechanisms.
