EFFECT OF TNFRp55 DEFICIENCY ON THE INFLAMMATORY PROCESS EXHIBITED AT THE END OF PREGNANCY

ARIAS JL; RAGUSA JA; CARGNELUTTI E; CASAIS M; ANZULOVICH AC; DI GENARO MS

Potrero de los Funes, San Luis

Congreso; XLVII Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2011

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

Tumor necrosis factor is a pleiotropic pro-inflammatory cytokine and TNF receptor p55 (TNFRp55) mediates most of the TNF effects. Pregnancy, either with or without signs of infection, show elevated levels of pro-inflammatory cytokines in maternal serum and fetal membranes when parturition is imminent. How this inflammatory milliu could impact on the maternal synovial membrane has not been investigated. Our objective was to study the consequences of TNFRp55 deficiency on the interleukine(IL)-17 and progesterone (Pg) levels in the joint of C57BL/6 wild type (WT) and TNFRp55-/- (KO) mice. IL-17 and Pg were determined by ELISA and RIA, respectively. We found elevated levels of IL-17 at the end of pregnancy in WT mice compared to diestrous stage. Moreover, IL-17 levels were lower in KO than WT mice at the end of pregnancy (p<0.01). Interestingly, this cytokine exhibited a circadian profile in the joint of WT which was abolished in the deficient mice. On the other hand, Pg also showed a circadian rhythm in both strains. The rhythm acrophase was advanced in the KO mice. Although, there was no difference in the levels of this hormone at the end of pregnancy, we found lower levels of Pg in KO mice at the diestrous (p<0.01). These results suggest that TNFRp55 signaling plays a key role in the inflammatory process that constitutes normal-term labour as well as in its circadian modulation.