Effect of TNFRp55 deficiency on the circadian profiles of immunoendocrine signals.

ARIAS JOSÉ LUIS; RAGUSA JOSÉ ANTONIO; DE LA VEGA MAGALÍ; CASAIS MARILINA; DI GENARO MARIA SILVIA; RASTRILLA ANA MARIA; ANZULOVICH ANA CECILIA

PUERTO MADRYN, CHUBUT

Congreso; 46º REUNION ANUAL SOCIEDAD ARGENTINA DE INVESTIGACION EN BIOQUIMICA Y BIOLOGIA MOLECULAR; 2010

SOCIEDAD ARGENTINA DE INVESTIGACION EN BIOQUIMICA Y BIOLOGIA MOLECULAR

The biological rhythms in the peripheral clocks are regulated by neuroimmunendocrine signals proceeding, directly or indirectly, from the master clock in the suprachiasmatic nucleus. TNF is a pleiotropic inflammatory cytokine and exhibits its biological properties upon binding to its cognate membrane receptors TNFRp55 and TNFRp75. Our objective was to assess the impact of TNFRp55 deficiency on the circadian profiles of the rest-activity cycle, IL-17 and progesterone (Pg) levels in C57BL/6 wild type and TNFRp55-/- mice. Circadian locomotor activity was registered under constant darkness during 20 days using the Archron system. IL-17 and Pg levels were determined by ELISA and RIA, respectively. We observed nocturnal activity decreased and desynchronized in the TNRFp55-/- mice. IL-17 levels vary throughout a day in serum, joint, ovary and liver in the wild type strain. Pg also showed a circadian profile in the same tissues except liver. Interestingly TNFRp55 deficiency phase shifted most of those temporal oscillations. These results suggest that TNF would play a role in the circadian modulation of endogenous rhythms through its p55 receptor.