Hypothyroidism sensitizes activation and NET formation in neutrophils

CORIA M.J.1, GOMEZ-MEJIBA S.E.2, RAMIREZ D.C.2, GIMENEZ M.S.1

Puerto Madryn

Congreso; SAIB 2010; 2010

Hypothyroidism sensitizes activation and NET formation in neutrophils   Coria M.J.1, Gomez-Mejiba S.E.2, Ramirez D.C.2, Gimenez M.S.1 1Universidad Nacional de San Luis, IMIBIO-SL, CONICET and 2Oklahoma Medical Research Foundation, OK, USA.   Upon activation with chemotactic compounds neutrophils or polymorphonuclear leukocytes (PMN) form extracellular traps (neutrophil’s extracellular traps, NETs). This event depends on the activation NADPH oxidase-2 (NOX-2). We think that hypothyroidism (H) sensitizes activation of PMN. To test this we used a model of H induced with 6-n-propylthiouracil (PTU) in female Wistar rats. Rats received drinking water without (control, CO) or with 0.1 g/L of PTU (hypothyroid, HT) for 30 days.  Rats were euthanized by decapitation and blood was collected for PMN isolation by gradient density centrifugation. PMN were cultured for 24 h in the presence or not of 10 µM fMLP. NOX-2, myeloperoxidase (MPO) and NET formation in PMN, were determined by immunocytochemistry and confocal imaging in single plan images. The MPO activity was measured by spectrophotometry using o-dianisidine as substrate. Nitric oxide (NO) levels in culture supernatant were measured as nitrites with the Griess reagent. Our results show an increased NOX-2 and MPO content in PMN of HT. Overall MPO activity remained unchanged. Activated PMN from HT rats showed increased fMLP-induced formation of NETs. Nitrite production was higher in PMN from HT rats. Our results suggest that hypothyroidism sensitizes neutrophils to activation and NET formation. This research will contribute to the understanding the impact of H on inflammation.