OSTEOCYTES CONTRIBUTE TO BONE PATHOLOGY IN GAUCHER DISEASE

BONDAR CONSTANZA; MUCCI JUAN MARCOS; CRIVARO ANDREA; ORMAZABAL MAXIMILIANO; CECI ROMINA; FERREYRA MALENA; DELPINO MARIA VICTORIA; ROZENFELD PAULA

San Diego

Simposio; 13TH ANNUAL WORLDSymposium; 2017

Gaucher disease (GD) is caused by a deficiency of the lysosomal enzyme glucocerebrosidase leading to the accumulation of glucosylceramide. Bone pathology in GD is a complex process which may include an increment in bone resorption by osteoclasts. This could be due to an increment in the number of osteoclasts, induced by RANKL and cytokines. Osteocytes can also regulate osteoclastogenesis by the release of soluble factors or by apoptosis. It is known that connexin43 (Cx43) is expressed in bone cells and its function is essential for survival. The aim of our work was to study the involvement of osteocytes in bone pathology of GD. The study was performed using the MLO-Y4 osteocyte cell line treated with CBE (an inhibitor of glucocerebrosidase) at different time points. The osteoclastogenic potential of conditioned media (CM) from CBE treated osteocytes was evaluated by osteoclast differentiation assays. RANKL levels were evaluated by immunofluorescence, Cx43 expression was assessed by qPCR and apoptosis was studied by Annexin-V and TUNEL staining. To study the mechanism on osteoclast differentiation, the apoptotic body fraction of the CM and its supernatant were obtained by centrifugation. Both fractions were used in osteoclastogenesis assays with or without OPG. CM from CBE treated osteocytes induced higher levels of osteoclast differentiation compared to control CM (p