Bone Abstracts

Osteoclasts are produced by fusion of pre-osteoclasts derived from stem cells of the monocyte/macrophage lineage in the presence of receptor activator of NF-κB ligand (RANKL) produced by osteoblasts. The phytoestrogens; genistein and daidzein, which are isoflavones found in Leguminosae such as soybeans, are currently being investigated for prevention of postmenopausal osteoporosis. Some polyunsaturated fatty acids (PUFAs) have been shown to exert a bone protectiv...

The PTH type 1 receptor (PTH1R) is an important modulator of bone remodeling. In mice, PTH1R ablation in osteocytes produces trabecular bone reduction and impaired calcium homeostasis; meanwhile, its overexpression in these cells promotes periosteal and endocortical bone formation. Osteocytes can translate mechanical stimuli into bone-forming signals. Skeletal unloading induces osteocyte apoptosis and bone loss, whereas mechanical stimuli prevent osteocyte apoptosis through in...

Introduction: Osteoporosis is a common complication in patients with chronic cholestasis, usually characterized by reduced bone formation. Ursodeoxycholic acid (UDCA) improves differentiation and mineralization and counteracts the damaging effects of bilirubin and lithocholic acid (LCA) in osteoblastic cells. Moreover, UDCA decreases apoptosis in a number of cell lines, but this antiapoptotic effect has not been investigated in bone cells.Aims: To assess...

Bisphosphonates are used to treat bone disease characterised by increased bone resorption by inhibiting the activity of mature osteoclasts, resulting in decreased bone turnover. Bisphosphonates may reduce the population of osteoclast precursor cells (OPCs). Our aims were to investigate the effect of bisphosphonates on i) OPCs and ii) bone turnover in postmenopausal women with osteoporosis compared with healthy premenopausal women. Participants were 62 postmenopausal women (mea...

Tumour growth and metastatic dissemination are significantly reduced in mice bearing an inactivation of the macrophage-colony stimulating factor (M-CSF) gene, due to angiogenesis impairment. In fact, M-CSF directly induces angiogenesis by increasing vascular endothelial growth factor (VEGF) production. Interleukin 34 (IL34), the M-CSF’s ‘twin’ cytokine, was characterized as a new cytokine promoting the growth, survival and differentiation of the myeloid lineage....

Bisphosphonates (BPs) are widely used as antiresorptive drugs. However, one of most potent BPs, zoledronic acid (ZA) can cause BP-related osteonecrosis of the jaws (BRONJ) with a poorly understood pathophysiology. The aim of this study was to find a clue for the development of BRONJ by evaluating the cytotoxic effects of ZA on osteoblasts and examining the action mechanism of ZA on osteoclast differentiation. Jaw bone osteoblasts (JB-OBs), long bone osteoblasts (LB-OBs), and b...

Only minor literature on histopathologic changes in Blount’s disease is available. This study presents the histologic findings of biopsies harvested from the medial and lateral part of the proximal tibia during the W/M serrated osteotomy in patients with infantile Blount’s disease, performed in Ghana. In this study it is hypothesized that the medial metaphyseal area in these children will present a different histological morphology compared to the lateral metaphyseal...

Mammalian target of rapamycin (mTOR) functions mainly in the form of two complexes, namely mTORC1 and mTORC2, which are distinct in their unique components, raptor and rictor. Here, we focused on bone phenotypes in mice with a specific deletion of rictor using a Cre recombinase gene whose expression was driven by the promoter of osteocalcin. All procedures involving mice were approved by the Institutional Animal Care and Use Committee of the local admin. DXA analysis showed a ...

Low bone formation is considered to be the main feature in osteoporosis associated with cholestatic and end-stage liver diseases. Previous studies have demonstrated the deleterious consequences of retained substances such as lithocholic acid (LCA) and bilirubin (Bil) on osteoblastic cells. These effects are neutralized by ursodeoxycholic acid (UDCA). To gain new insights into cholestatic-induced osteoporosis, we have assessed the differential gene expression of osteoblastic ce...

I will describe non-cancerous skeletal diseases that occur as a consequence of somatic mutation. I will introduce the work of Drs Mary Lyon, Dorothea Bennett, and Rudolf Happle that provided insights into the mechanism responsible for several genetic, non-heritable diseases. I will then describe the technology and analytic strategies that several laboratories, including my own, employed to identify mutations in patients with Maffucci, Proteus, CLOVES, and Klippel-Trenaunay syn...