Osteocyte alterations contribute to bone pathology in Gaucher Disease

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

Congreso; The European Working Group on Gaucher Disease Congress; 2016

The aim of our work wasto evaluate the involvement of osteocytes in the bone pathology of Gaucherdisease (GD). The study was performed with an in vitro model using the MLO-Y4 osteocyte cell line treated withCBE at different time points. Osteoclastogenic potential of conditioned media (CM)from CBE treated ostecytes was evaluated by osteoclast differentiation assays,and RANKL levels were evaluated by immunofluorescence. Connexin-43 expressionwas assessed by qPCR and apoptosis was studied by Annexin-V and TUNEL stainings.To study the mechanism on osteoclast differentiation, the apoptotic bodyfraction of the CM and its supernatant were obtained by centrifugation. Bothfractions were used in osteoclastogenesis assays with or without OPG. The CMfrom CBE treated osteocytes induced higher levels of osteoclast differentiation(p<0,01) compared to control CM and higher surface RANKL levels wereobserved in treated cells (p<0,05). Connexin-43 expression diminished withCBE treatment (p<0,01) and osteocyte apoptosis was increased (p<0,05).The induction of osteoclast differentiation by apoptotic bodies and supernatantwas higher in CBE treated CM in both fractions (p<0,01), and treatment withOPG reduced osteoclast levels in both cases (p<0,001). In conclusion, weshowed a potential role of osteocytes in bone pathology of GD by induction ofosteoclast differentiation. This effect could be related to a higher apoptoticstate in osteocytes as well as the RANKL induction pathway.