Searchable abstracts of presentations at key conferences on calcified tissues

ba0001pp434 | Osteoporosis: treatment | ECTS2013

Bone histology and histomorphometry: effects of 5 years of denosumab in the FREEDOM Extension

Brown Jacques P , Wagman Rachel , Dempster David W , Kendler David , Miller Paul , Bolognese Michael , Valter Ivo , Beck Jensen Jens-Erik , Zerbini Cristiano , Zanchetta Jose R , Daizadeh Nadia , Reid Ian

DMAb increases BMD and reduces bone resorption and risk of vertebral, nonvertebral and hip fractures in women with PMO. Transiliac crest bone biopsies in 47 subjects treated with DMAb for 1–3 years showed reduced bone turnover vs 45 Pbo-treated subjects, which reversed on treatment cessation. Since bone turnover reduction is sustained and fracture incidence low over 6 years’ DMAb treatment, we evaluated DMAb’s effects on tissue-level remodelling in the FREEDOM E...

ba0001pp60 | Bone development/growth and fracture repair | ECTS2013

MEK inhibitors in fracture healing and NF1 pseudarthrosis

Little David , El-Hoss Jad , Kollind Mille , Deo Nikita , McDonald Michelle , Sullivan Kate , Little Chris , Schindeler Aaron

Neurofibromatosis type 1 (NF1) is a genetic disorder with an incidence of 1/3000. Inactivating mutations in the NF1 gene cause Ras-MEK overstimulation, and predisposes NF1 patients to cancer. A new generation of MEK inhibitors (PD0325901 and AZD6244) are under clinical trials in cancer patients, including NF1 patients. Congenital pseudarthrosis of the tibia is a major complication for NF1 patients, and associates with loss-of-heterozygosity of the NF1 gene. The primary aim of ...

ba0001pp181 | Cell biology: osteoblasts and bone formation | ECTS2013

The impairement of bone formation and mineralization in BSP−/− mouse calvaria cell cultures is partly rescued by increasing cell density

Bouet Guenaelle , Bouleftour Wafa , David Marchat , Marie-Therese Linossier , Mireille Thomas , Jane Aubin E , Laurence Vico , Luc Malaval

Bone sialoprotein regulates osteoblast activity and bone formation. In knockout (BSP−/−) mouse bone marrow (BM) stromal cell cultures, the pool of osteoprogenitor (OP) cells (CFU-F number) is not different from wild-type (+/+), nor is their early differentiation (same numbers of alkaline phosphatase positive colonies=CFU-ALP, although these are smaller), while the number of osteoblast, mineralized colonies (CFU-OB) is dramatically reduced. Because ossifi...

ba0001pp501 | Other diseases of bone and mineral metabolism | ECTS2013

Abnormal type I collagen glycosylation pattern and cross-linking in a cyclophilin B KO mouse model of recessive osteogenesis imperfecta

Cabral Wayne , Perdivara Irina , MaryAnn Weis , Terajima Masahiko , Blissett Angela , Chang Weizhong , Makareeva Elena , Leikin Sergey , Eyre David , Yamauchi Mitsuo

Introduction: Recessive osteogenesis imperfecta (OI) is caused by mutations in genes encoding proteins involved in post-translational interactions with type I collagen. Types VII–IX OI involve defects in the collagen prolyl 3-hydroxylation complex, which modifies α1(I)Pro986. PPIB encodes CyPB, a complex component with PPIase activity and the major isomerase facilitating collagen folding. We investigated the role of CyPB in collagen post-translational modifications a...

ba0002oc29 | Chronic diseases | ICCBH2013

Mineral metabolism, cortical volumetric bone mineral density and fracture risk in childhood chronic kidney disease

Denburg Michelle , Tsampalieros Anne , de Boer Ian , Shults Justine , Kalkwarf Heidi , Zemel Babette , Foerster Debbie , Stokes David , Leonard Mary

Background and Objectives: The relations among cortical volumetric bone mineral density (CortBMD) and comprehensive measures of mineral metabolism have not been addressed in chronic kidney disease (CKD). The aim was to identify determinants of CortBMD in childhood CKD. A secondary objective was to assess if CortBMD was associated with subsequent fracture.Design/participants: This prospective cohort study in children, adolescents and young adults (ages 5&...

ba0003cc3 | (1) | ECTS2014

Absence of ER cation channel TMEM38B/TRIC-B causes recessive osteogenesis imperfecta by dysregulation of collagen post-translational modification

Cabral Wayne , Makareeva Elena , Ishikawa Masaki , Barnes Aileen , MaryAnn Weis , Lacbawan Felicitas , Eyre David , Yamada Yoshihiko , Leikin Sergey , Marini Joan

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...

ba0003pp141 | Cell biology: osteoblasts and bone formation | ECTS2014

An infrared assay of the kinetics of phosphate-release from physiological substrates in living cells

Zhongyuan Ren , Leduy Do , Mebarek Saida , Keloglu Nermin , Ahamada Saandia , Meena Saurabh , Magne David , Pikula Slawomir , Wu Yuqing , Buchet Rene

Up to now, most of standard methods for measuring inorganic phosphate (Pi) to determine phosphatase activity are based on coupled enzyme assays, colorimetric methods or conductance measurements. However, none of these methods can measure Pi, substrate and protein concentrations simultaneously, allowing direct kinetic determinations of phosphatase activity in cells in a single assay. Among the enzymes having a pyrophosphatase activity and releasing Pi...