Study Of The Mechanisms Of Osteoclastogenesis Induction In An In Vitro Model Of Gaucher Disease

ROZENFELD PA; MUCCI J; DE FRANCESCO, PN; SCIAN R; DELPINO, MV

Congreso; Lysosomal Disease Network-8th Annual WORLD Symposium; 2012

Deficient glucocerebrosidase enzymatic activity in Gaucher disease (GD) leads to accumulation of glucocerebroside in macrophages. Pathological mechanisms of bone alterations in type I GD are still poorly understood. We hypothesized that cellular alteration in GD produces a proinflammatory milieu leading to bone destruction through enhancement of macrophages differentiation to osteoclasts and osteoclasts resorption activity. The aim of this work was to evaluate the capacity and the mechanisms by which soluble mediators secreted by an in vitro chemical model of GD cells induce osteoclastogenesis. Peripheral blood mononuclear cells from control individuals were exposed to Conduritol β-epoxide and lipopolysaccharide. Cytokine and RANKL secretion was determined in culture supernatants (CS1). In order to determine the capacity of soluble mediators from CS1 to induce osteoclastogenesis, we added CS1 to a monocytic leukemia cell line (THP-1) in the presence of M-CSF. Osteoclastogenesis induction was determined by the measurement of multinucleated TRAP positive cells, osteolysis and CD51 expression. Moreover, we determined chitotriosidase activity, cytokine production and MMP activity in culture supernatant of differentiated osteoclasts (CS2). We detected high levels of proinflammatory cytokines such as IL-1β, TNF-α and IL-6 but not RANKL in CS1. Addition of CS1 to osteoclasts precursors induced an increase of TRAP+ multinucleated cells, CD51 expression and osteolytic activity. Analysis of CS2 revealed the presence of proinflammatory cytokines, augmented production of MMP-9 and chitotriosidase activity from differentiated osteoclasts. In conclusion, human in Vitro model of Gaucher disease exhibited the capacity of osteoclastogenesis induction associated to the production of proinflammatory cytokines but not RANKL.