RESUMO
Although several independent studies of gene expression patterns during osteoblast differentiation in cultures from calvaria and other in vitro models have been reported, only a small portion of the mRNAs expressed in osteoblasts have been characterized. We have previously analyzed the behavior of several known markers in osteoblasts, using Affymetrix GeneChip murine probe arrays (27,000 genes). In the present study we report larger groups of transcripts displaying significant expression modulation during the culture of osteoblasts isolated from mice calvaria. The expression profiles of 601 such regulated genes, classified in distinct functional families, are presented and analyzed here. Although some of these genes have previously been shown to play important roles in bone biology, the large majority of them have never been demonstrated to be regulated during osteoblast differentiation. Despite the fact that the precise involvement of these genes in osteoblast differentiation and function needs to be evaluated, the data presented herein will aid in the identification of genes that play a significant role in osteoblasts. This will provide a better understanding of the regulation of osteoblast differentiation and maturation.
Assuntos
Análise de Sequência com Séries de Oligonucleotídeos , Osteoblastos/citologia , Osteoblastos/fisiologia , Crânio/citologia , Animais , Moléculas de Adesão Celular/genética , Diferenciação Celular/genética , Células Cultivadas , Proteínas do Citoesqueleto/genética , Endopeptidases/genética , Proteínas da Matriz Extracelular/genética , Genoma , Substâncias de Crescimento/genética , Camundongos , Camundongos Endogâmicos , Receptores de Superfície Celular/genética , Inibidores Teciduais de Metaloproteinases/genética , Fatores de Transcrição/genéticaRESUMO
Several genes, such as alkaline phosphatase, osteocalcin, and Cbfa1/Osf2, are known to be regulated during osteoblastic differentiation and are commonly used as "osteoblast markers" for in vitro or in vivo studies. The number of these genes is very limited, however, and it is of major interest to identify new genes that are activated or repressed during the process of osteoblast differentiation and bone formation as well as to extend the available information on gene families relevant to this particular differentiation pathway. To identify such genes, we have implemented a genome-wide analysis by determining changes in expression levels of 27,000 genes during in vitro differentiation of primary osteoblasts isolated from mouse calvaria. This study focuses on the description of the analytical and filtering process applied; on the transcriptional analysis of well-established "bone," "adipocyte," and "muscle" pathway markers; and on a description of the regulation profiles for genes recently described in the Skeletal Gene Database. We also demonstrate that new array technologies constitute reliable and powerful tools to monitor the transcription of genes involved in osteoblastic differentiation, allowing a more integrated vision of the biological pathways regulated during osteoblast commitment, differentiation, and function.
Assuntos
Adipócitos/metabolismo , Perfilação da Expressão Gênica/métodos , Genoma , Mioblastos/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Osteoblastos/metabolismo , Crânio/metabolismo , Adipócitos/citologia , Animais , Animais Recém-Nascidos , Células Cultivadas , Bases de Dados Genéticas/estatística & dados numéricos , Marcadores Genéticos/genética , Camundongos , Mioblastos/citologia , Osteoblastos/citologia , Crânio/citologiaRESUMO
A series of novel, highly potent alpha(v)beta(3) antagonists based on a thiophene scaffold and containing an acylguanidine as an Arg-mimetic is described. A number of structural features, such as cyclic versus open guanidine and a variety of lipophilic side chains, carbamates, sulfonamides and beta-amino acids were explored with respect to inhibition of alpha(v)beta(3) mediated cell adhesion and selectivity versus alpha(IIb)beta(3) binding. In addition, compound 19 was found to be active in the TPTX model of osteoporosis.