Endochondral bone formation has been fairly well characterized from a morphological perspective and yet this process remains largely undefined at molecular and biochemical levels. In vitro and in vivo studies have shown that @entity1 @entity1841 ( @entity1841 ) is an important developmental growth and differentiation factor, capable of inducing ectopic bone formation in vivo. This study evaluated several aspects of the osteogenic effect of @entity1841 protein injected into quadriceps of female C57B1/6J @entity915 @entity19 . @entity19 were euthanized 1, 2, 3, 4, 7, and 14 days postinjection and muscles were collected for several methods of analysis. @entity1710 and @entity1711 -stained sections of muscles injected with formulation buffer showed no evidence of osteogenesis. In contrast, sections of muscles injected with @entity1841 showed evidence of endochondral bone formation that progressed to mineralized bone by day 14. In addition, radiographs of @entity19 injected with @entity1841 showed that much of the quadriceps muscle had undergone mineralization by day 14. Labeled mRNA solutions were prepared and hybridized to oligonucleotide arrays designed to monitor approximately 1300 @entity19 , full-length genes. Changes in gene expression associated with @entity1841 were determined from time-matched comparisons between buffer and @entity1841 samples. A gene expression profile was created for 215 genes that showed greater than 4-fold changes at one or more of the indicated time points. One hundred twenty-two of these genes have previously been associated with bone or cartilage metabolism and showed significant increases in expression, e.g., aggrecan ( @entity36448 ), @entity2447 ( @entity2447 ), @entity2450 ( @entity2450 ), and procollagens type II ( @entity15137 ) and X ( @entity21272 ). In addition, there were 93 genes that have not been explicitly associated with bone or cartilage metabolism. Two of these genes, @entity24440 ( @entity24440 ) and @entity70501 ( @entity70501 ), showed peak changes in gene expression of 15- and 40-fold on days 4 and 7, respectively. In situ hybridizations of muscle sections showed that @entity70501 and @entity24440 mRNAs were expressed in chondrocytes and osteoblasts, suggesting a role for both proteins in some aspect of cartilage or bone formation. In conclusion, oligonucleotide arrays enabled a broader view of endochondral bone formation than has been reported to date. An increased understanding of the roles played by these gene products will improve our understanding of skeletogenesis, @entity174 repair, and pathological conditions such as @entity170 .

A gene expression profile for endochondral bone formation: oligonucleotide microarrays establish novel connections between known genes and BMP-2-induced bone formation in XXXX quadriceps.

@entity1 :: ('9606', 'Species') :: ['human'] @entity1841 :: ('650', 'Gene') :: ['bone morphogenetic protein-2', 'hBMP-2'] @entity174 :: ('MESH:D050723', 'Disease') :: ['fracture'] @entity2447 :: ('12393(Tax:10090)', 'Gene') :: ['Runx2', 'runt related transcription factor 2'] @entity19 :: ('10090', 'Species') :: ['mice', 'Mice', 'murine'] @entity2450 :: ('12097(Tax:10090)', 'Gene') :: ['bone Gla protein 1', 'Bglap1'] @entity1711 :: ('MESH:D004801', 'Chemical') :: ['eosin'] @entity70501 :: ('26561(Tax:10090)', 'Gene') :: ['Mmp23', 'matrix metalloproteinase 23'] @entity170 :: ('MESH:D010024', 'Disease') :: ['osteoporosis'] @entity15137 :: ('12824(Tax:10090)', 'Gene') :: ['Col2a1'] @entity915 :: ('MESH:D053632', 'Disease') :: ['SCID'] @entity1710 :: ('MESH:D006416', 'Chemical') :: ['Hematoxylin'] @entity24440 :: ('12931(Tax:10090)', 'Gene') :: ['cytokine receptor-like factor-1', 'Crlf1'] @entity36448 :: ('11595(Tax:10090)', 'Gene') :: ['Agc1'] @entity21272 :: ('12813(Tax:10090)', 'Gene') :: ['Col10a1']
@entity19 :: (10090,Species) :: ['mouse']
