Bone Abstracts

Biographical DetailsCraig B LangmanProfessor Craig B Langman, is the Isaac A Abt, MD, Professor of Kidney Diseases at the Feinberg School of Medicine, Northwestern University, Head of Kidney Diseases at the Ann and Robert H Lurie Children’s Hospital of Chicago. His research focuses on the basic and clinical expression of inherited or acquired d...

C-C chemokine receptor 5 (CCR5) is a co-receptor of macrophage-tropic viruses including HIV. Epidemiological and pathological findings have reported that functional changes in CCR5 correlate with HIV transmission bone destruction disease. However, the roles of CCR5 in bone pathophysiology have not been well documented.Ccr5-deficient osteoclasts showed decreased bone resorption activity accompanied with disorganized cellular architecture and impa...

Introduction: Activated protein C (APC) plays an important role in the cutaneous healing of chronic wounds arising from orthopaedic surgery and has cytoprotective and anti-inflammatory properties which may also assist bone repair. The aim of this study was to examine whether APC could directly influence osteoblasts and increase bone formation in a rodent model.Methods: Proliferation of MG-63 osteoblast-like cells was quantified by MTT assay and direct co...

Early-onset Paget’s disease of bone (ePDB), familial expansile osteolysis (FEO) and expansile skeletal hyperphosphatasia (ESH) are related syndromes caused by heterozygous tandem insertion duplication mutations within the signal peptide region of TNFRSF11a (encoding receptor activator of NFκB; RANK). Given that patients are always heterozygous for these mutations we have generated thirteen cell lines to investigate the molecular consequences of these mutations in...

Recessive osteogenesis imperfecta (OI) is caused by mutations in genes encoding proteins involved in post-translational interactions with type I collagen. A founder mutation in a new gene responsible for recessive OI has recently been reported in Bedouins from Israel and Saudi Arabia, who have a homozygous deletion of TMEM38B exon 4 and surrounding intronic sequence. TMEM38B encodes TRIC-B, an integral ER membrane monovalent cation channel involved in Ca...

Tyrosine kinase c-Src plays an important role in actin ring formation and bone resorption activity in osteoclasts. Therefore, c-Src has been targeted for the treatment of osteolytic disorders. In the present study, we investigated anti-resorptive effect of dibenzazepine (DBZ), one of the γ-secretase inhibitors (GSIs), on osteoclast-mediated excessive bone resorption. DBZ did not affect osteoclast differentiation, but disturbed actin ring formation and inhibited osteoclast...

Distal-less homeobox 5 (Dlx5) is a transcription factor that enhances osteogenic differentiation of mesenchymal stem cells via upregulating the expression of Runx2 and other osteoblast phenotypic genes. We have previously demonstrated that Dlx5 also downregulates adipogenic differentiation of mesenchymal stem cells and that insulin decreases expression levels of Dlx5 via increasing expression levels of miR-124, a microRNA targeting 3′UTR of Dlx5. However, the mechanism o...

Bone density (BMD) loss is a consequence of aromatase inhibitors (AI) treatment of breast cancer. B-ABLE cohort includes 391 postmenopausal women with early breast cancer starting AI therapy. Participants experienced a 1.98% (95% CI 1.54–2.42% P<0.0001) bone loss at lumbar spine (LS) and 1.24% (95% CI 0.81–1.67% P<0.0001) bone loss at femoral neck (FN) after 1 year on AI therapy and a 3.51% (95% CI 3.00–4.03% P<0.0001) bone...

High Bone Mass (HBM) osteogenesis imperfecta (OI) is caused by dominant mutations in the C-propeptide cleavage site of COL1A1 or COL1A2, characterized by bone hypermineralization. To elucidate the role of C-propeptide processing in bone mineralization and development, we generated heterozygous HBM mice with both residues (Ala-Asp) of the COL1A1 cleavage site substituted (Thr-Asn) to prevent processing by BMP1. Two, 6- and 12-month WT and HBM bones were examin...

Familial expansile osteolysis (FEO) is characterised by focal areas of increased bone turnover driven by bone-resorbing osteoclasts. The syndrome is caused by a heterozygous tandem insertion duplication mutation within the signal peptide region of TNFRSF11a (encoding receptor activator of NFκB; RANK). Our recent research has demonstrated that heterotrimeric receptor formation may hold the key to the disease phenotype. We have shown previously that, whilst homozygous overe...