Hedgehog and canonical Wnt/beta-catenin signaling are implicated in development of the osteoblast, the bone matrix-secreting cell of the vertebrate skeleton. We have used genetic approaches to dissect the roles of these pathways in specification of the osteoblast lineage. Previous studies indicate that Ihh signaling in the long bones is essential for initial specification of an osteoblast proge...

Early B-cell factor 1 (Ebf1) is a transcription factor whose inactivation in all cells results in high bone mass because of an increase in bone formation. This observation suggests Ebf1 may be an inhibitor of osteoblast differentiation. To test this contention, we analyzed Ebf1 pattern of expression and function in osteoblasts ex vivo and in vivo through osteoblast-specific inactivation in the ...

introduction : deproteinized bovine bone mineral (bio-oss) is a xenogenic bone substitute, widely used in maxillofacial bone regeneration. the aim of this in vitro study was to investigate its influence on the growth behavior of human osteosarcoma cell line, saos-2 culture, and compare it with the physiologic dose of dexamethasone, an inductive factor for osteoblasts. materials and methods: hum...

p53 is a well known tumor suppressor. We show that p53 also regulates osteoblast differentiation, bone formation, and osteoblast-dependent osteoclast differentiation. Indeed, p53(-/-) mice display a high bone mass phenotype, and p53(-/-) osteoblasts show accelerated differentiation, secondary to an increase in expression of the osteoblast differentiation factor osterix, as a result. Reporter as...

JMJD3 (KDM6B) is an H3K27me3 demethylases and emerges as an important player in developmental processes. Although some evidence indicated the involvement of JMJD3 in osteoblast differentiation in vitro, its role as a whole in osteoblast differentiation and bone formation in vivo remains unknown. Here we showed that homozygous deletion of Jmjd3 resulted in severe delay of osteoblast differentiat...

Statins, drugs commonly used to lower serum cholesterol, have been shown to stimulate osteoblast differentiation and bone formation. Statins inhibit 3-hydroxy-3-methylglutaryl (HMG)-coenzyme A reductase (HMGCR), the first step of the isoprenoid biosynthetic pathway, leading to the depletion of the isoprenoids farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). The effects of s...

The most biologically active metabolite 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) has well known direct effects on osteoblast growth and differentiation in vitro. The precursor 25-hydroxyvitamin D3 (25(OH)D3) can affect osteoblast function via conversion to 1,25(OH)2D3, however, it is largely unknown whether 25(OH)D3 can affect primary osteoblast function on its own. Furthermore, 25(OH)D3 is not o...

Vertebrate skeletogenesis involves two processes, skeletal patterning and osteoblast differentiation. Here, we show that Satb2, encoding a nuclear matrix protein, is expressed in branchial arches and in cells of the osteoblast lineage. Satb2-/- mice exhibit both craniofacial abnormalities that resemble those observed in humans carrying a translocation in SATB2 and defects in osteoblast differen...

Bone formation is a complex developmental process involving the differentiation of mesenchymal stem cells to osteoblasts. Osteoblast differentiation occurs through a multi-step molecular pathway regulated by different transcription factors and signaling proteins. Osx (also known as Sp7) is the only osteoblast-specific transcriptional factor identified so far which is required for osteoblast dif...

Brucella abortus induces an inflammatory response that stimulates the endocrine system resulting in the secretion of cortisol and dehydroepiandrosterone (DHEA). Osteoarticular brucellosis is the most common presentation of the active disease in humans, and we have previously demonstrated that B. abortus infection inhibits osteoblast function. We aimed to evaluate the role of cortisol and DHEA o...