Searchable abstracts of presentations at key conferences on calcified tissues

ba0003pp161 | Cell biology: osteoclasts and bone resorption | ECTS2014

Ultrastructural imaging of the osteoclast secretory machinery in 3 dimensions

Helfrich Miep , Wilkinson Debbie , Mackenzie Kevin , Greenhorn John , Coxon Fraser

Osteoclasts secrete acid and cathepsin K to dissolve the mineral and digest the organic matrix of bone, cartilage and dentine. The secretions are by necessity destructive and potentially harmful to the cell itself and are therefore trafficked through the cell in membrane bound vesicles. Secretion takes place over a specialised membrane compartment, the ruffled border, which is only present in resorbing osteoclasts. The ruffled border membrane and the vesicles in its vicinity h...

ba0001pp211 | Cell biology: osteoblasts and bone formation | ECTS2013

Rab27a is involved in bone formation by osteoblasts

Coxon Fraser , Douglass Angela , Hughes Alun , Helfrich Miep , Seabra Miguel , Tolmachova Tanya

The Rab family GTPases Rab27a and Rab27b play an important role in the trafficking of lysosome-related organelles in specialised cells, such as melanocytes. Since secretory lysosomes, also considered a lysosome-related organelle, are important for osteoclast and osteoblast function, we hypothesised that Rab27 plays a role in bone physiology. In support of this, a recent study demonstrated impaired transport of RANK ligand to the plasma membrane in osteoblasts from mice lacking...

ba0002p132 | (1) | ICCBH2013

Studies on bone and osteoclasts in patients with Shwachman Diamond syndrome

Helfrich Miep , Mellis David , Coxon Fraser , Greenhorn John , Kuijpers Taco , Crockett Julie

Shwachman Diamond syndrome (SDS; MIM 260400) is a monogenic, autosomal recessive, pancreatic condition often accompanied by low bone mass and fracture. In SDS, as in cystic fibrosis, a low bone mass may be secondary to poor nutrition or chronic low-grade infection, but it has also been suggested there may be a primary bone phenotype. Paradoxically, recent studies in cell lines and in a mouse knockout for the SBDS gene, have suggested changes in important osteoclast gr...

ba0005p195 | Cell biology: osteoclasts and bone resorption | ECTS2016

The role of LC3 and autophagy in bone resorption by osteoclasts

Tran Anh , Coxon Fraser , McDermott Emma , Ganley Ian , Odgren Paul , Martinez Jennifer , Green Douglas , Helfrich Miep

The autophagy protein LC3 is necessary for bone resorption by osteoclasts, although it has been suggested that this may be through a novel, autophagy-independent process, by promoting lysosomal fusion at the ruffled border (RB). This process would be analogous to LC3-associated phagocytosis (LAP), in which LC3 is acquired by phagosomes through an autophagy-independent process, and controls phagosome maturation by promoting fusion with lysosomes. We have investigated this possi...