Searchable abstracts of presentations at key conferences on calcified tissues

ba0003pp133 | Cell biology: osteoblasts and bone formation | ECTS2014

Chemical composition of apatites formed by matrix vesicles during bone mineralization

Strzelecka-Kiliszek Agnieszka , Bozycki Lukasz , Buchet Rene , Pikula Slawomir

Bone cells control initial steps of mineralization by forming matrix vesicles (MVs) in which calcium and phosphate ions are accumulated. Under physiological conditions, MVs are released to the extracellular matrix (ECM) and Ca2+ and Pi form hydroxyapatite (HA). Growing minerals break the MVs membrane and are deposited in ECM. Under pathological conditions the mineralization process becomes deregulated, which leads to the formation of calcium phosphate deposits. It is suggested...

ba0005p170 | Cell biology: osteoblasts and bone formation | ECTS2016

Matrix vesicle-mediated mineralization depends on the balance between annexins and fetuin-A which may be modulated by TNAP and calcium channel inhibitors

Strzelecka-Kiliszek Agnieszka , Bozycki Lukasz , Roszkowska Monika , Pikula Slawomir

Bone mineralization is initiated by matrix vesicles (MVs), cell-derived structures released into the extracellular matrix which are nucleation sites for hydroxyapatite (HA) formation. It is suggested that annexins are mineralization-stimulating membrane proteins that exhibit ion channel activity and facilitate the influx of Ca2+ into MVs. The process is also regulated via enzymatic degradation of inhibitory pyrophosphate by tissue-nonspecific alkaline phosphatase (T...

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...