EFFECTS OF OXIDATIVE STRESS ON LYMPHOCYTE FUNCTIONALITY IN A MURINE MODEL OF HYPERTHYROIDISM. ROLE OF THE CELLULAR ANTIOXIDANT SYSTEM IN THE SCAVENGING OF OXYGEN FREE RADICALS

MACRI DELBONO R ; COSTILLA M ; ROMEO H ; KLECHA A ; CREMASCHI G ; BARREIRO ARCOS ML

CABA - VIRTUAL

Congreso; REUNIÓN DE SOCIEDADES DE BIOCIENCIAS 2020; 2020

SAFIS

Introduction: Thyroid hormones increase cellular metabolism andthe production of reactive oxygen species (ROS). ROS could act asa signaling molecule involved in cell functionality or exert cytotoxicactions depending on its intracellular concentration. The harmfuleffects of ROS are counteracted by the cellular antioxidant system.Objective: To study the effects of oxidative stress on lymphocytefunctionality in hyperthyroid mice, analyzing the role of antioxidantenzymes in the scavenging of ROS. Methods: Balb/c mice weretreated with placebo (euthyroid) or T4 (12 mg/l drinking water for30 days-hyperthyroid). ROS were evaluated by DCFH-DA stainingand flow cytometry. The expression of catalase (CAT), glutathioneperoxidase (GPx) and superoxide dismutase (SOD) was determinedby qPCR and WB. Apoptosis was evaluated by Annexin V-PI,Rhodamine-123 or Hoechst-33342 staining followed by flow cytometryor fluorescence microscopy. The number of follicles in lymphoidtissue sections stained with hematoxylin-eosin was determined bymicroscopy. Cell size and granularity was evaluated by flow cytometry.Proliferation was evaluated by incorporation of [3H]-thymidine.Results: We found an increased production of ROS in thelymph nodes (LN) and spleen (S) of hyperthyroid mice (% increaseLN:60.6±5.1; S:63.5±5.9, p