B. abortus infection modulates osteocyte function

AYELÉN I. PESCE VIGLIETTI; M. VIRGINA GENTILINI ; P. CONSTANZA ARRIOLA BENITEZ; LIS N. VELASQUEZ; GUILLERMO H. GIAMBARTOLOMEI; M. VICTORIA DELPINO

Mar del Plata

Congreso; LIX Reunión Científica Anual de la Sociedad Argentina de Investigación Clínica, LXII Reunión Científica Anual de la Sociedad Argentina de Inmunología; 2014

Sociedad Argentina de Investigación Clínica y Sociedad Argentina de Inmunología

Osteoarticular brucellosis is the most common localization of human active disease. Osteocytes are the most abundant cells of bone. They secrete factors that regulate osteoclast differentiation (cells involved in bone resorption). The aim is to determine if Brucella abortus (Ba) infection modifies osteocyte (MLO-Y4) function. Cytokine and chemokine production was determined by ELISA, osteoclast differentiation was determined by microscopy as the number of multinucleated cells that express tartrate-resistant acid phosphatase (TRAP). Conexin 43, E11/gp38, integrin-α and -β, tubulin-α, CD44 expression was determined by qRT-PCR. Apoptosis was determined by Hoechst dye 33342 (microscopy) and by Annexin V-FITC/Propidium Iodide (PI) (cytometry). Ba infection induced the secretion of pro-inflammatory cytokines (IL-6 and TNF-α, but not IL-1β), KC and RANKL (the main regulator of osteoclastogenesis) by osteocytes. In inflammatory condition TNF-α could be also involved in osteoclastogenesis. Our results indicated that supernatants from Ba infected osteocytes could induce osteoclast differentiation of monocytes in the presence of M-CSF (p