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

ARIAS JL; RAGUSSA V; CARGNELLUTTI E; CASAIS M; ANZULOVICH AC; DI GENARO MS

Potrero de los Funes, San Luis

Congreso; 47th. Annual meeting SAIB; 2011

SAIB

Tumor necrosis factor is a pleiotropic pro-inflammatory cytokineand TNF receptor p55 (TNFRp55) mediates most of the TNFeffects. Pregnancy, either with or without signs of infection, showelevated levels of pro-inflammatory cytokines in maternal serumand fetal membranes when parturition is imminent. How thisinflammatory milliu could impact on the maternal synovialmembrane has not been investigated. Our objective was to study theconsequences of TNFRp55 deficiency on the interleukine(IL)-17and progesterone (Pg) levels in the joint of C57BL/6 wild type (WT)and TNFRp55-/- (KO) mice. IL-17 and Pg were determined byELISA and RIA, respectively. We found elevated levels of IL-17 atthe end of pregnancy in WT mice compared to diestrous stage.Moreover, IL-17 levels were lower in KO than WT mice at the end ofpregnancy (p<0.01). Interestingly, this cytokine exhibited acircadian profile in the joint of WT which was abolished in thedeficient mice. On the other hand, Pg also showed a circadianrhythm in both strains. The rhythm acrophase was advanced in theKO mice. Although, there was no difference in the levels of thishormone at the end of pregnancy, we found lower levels of Pg in KOmice at the diestrous (p<0.01). These results suggest that TNFRp55signaling plays a key role in the inflammatory process thatconstitutes normal-term labour as well as in its circadianmodulation.