INVESTIGADORES
DELPINO Maria Victoria
congresos y reuniones científicas
Título:
Fever-Range hyperthermia improves the anti-apoptotic effect induced by low pH on human neutrophils promoting a proangiogenic profile. Fernando
Autor/es:
FERNANDO ERRA DIAZ; EZEQUIEL DANTAS; CABRERA MAIA; JOSEFINA CASTRO MAZA; CONSTANZA ARRIOLA BENITEZ; MARIA VICTORIA DELPINO; NORBERTO SAN JUAN; ANALÍA TREVANI; JORGE GEFFNER
Reunión:
Congreso; 61. LXIV Reunión Anual de la Sociedad Argentina de Inmunología (SAI). 15-19 Noviembre 2016.; 2016
Resumen:
Neutrophils have the shortest lifespan among leukocytesand usually die via apoptosis. We previously reportedthat low pH, a hallmark of inflammatory processesand solid tumors, moderately delays neutrophil apoptosis.Here we analyzed whether fever-range hyperthermia(39.5°C) was able to modulate the anti-apoptotic effectinduced by low pH (pH 6.0). Hyperthermia markedly increasedneutrophil survival induced by low pH (anexinV/PI staining/flow cytometry): % apoptosis = 72±5, 45±6,70±7, and 19±3, for neutrophils cultured for 18 h at pH7.3/37ºC, pH 6.0/37°C, pH 7.3/39.5ºC, and pH 6.0/39.5°C,respectively (p<0.001 for pH 6.0/39.5ºC vs pH 7.3/37°C,n=9). Similar results were observed when apoptosiswas evaluated by different methodologies. Analysis ofthe mechanisms underlying this anti-apoptotic responserevealed that hyperthermia further decreases cytosolicpH induced by extracellular acidosis, evaluated withBCECF-AM/flow cytometry (p<0.01, pH 6.0/37°C vs pH6.0/39.5°C). The fact that two Na+/H+ exchanger inhibitors,EIPA(10mM) and amiloride (1mM) reproduced the effectsinduced by hyperthermia suggested that it prolongs neutrophilsurvival by inhibiting the Na+/H+ anti-porter. Interestingly,we found that the anti-apoptotic effect induced bylow pH and hyperthermia is associated to the induction of afunctional profile characterized by a low phagocytic activityevaluated by fluorescence microscopy using FITC-labeledCandida albicans (% inhibition 56 ± 8, n=5, pH 6.0/39.5°Cvs pH 7.3/37°C, p<0.001), an impairment in ROS productionevaluated by DHR oxidation and flow cytometry(% inhibition >90%, n=7, pH 6.0/39.5°C vs pH 7.3/37°C,p<0.001), and a higher ability to produce the angiogenicfactors VEGF, IL-8 and the matrix metallopeptidase 9(MMP-9) evaluated by ELISA and zymography (p<0.01,pH 6.0/39.5°C vs pH 7.3/37°C, n=6). These results suggestthat acting together fever and local acidosis might drive thedifferentiation of neutrophils into a proangiogenic profile.