Altered glucocorticoid receptor activation during preovulatory period shifts inflammatory signals in the ovary of Dairy cattle under stress condition.

ETCHEVERS, L; BELOTTI, EM.; STASSI, AF; DÍAZ, PU; SALVETTI, NR; ORTEGA, HH; AMWEG, AN

Congreso; Reunión conjunta SAIC SAB AAFE AACYTAL 2023. LXVIII Reunión anual de la Sociedad Argentina de Investigación Clínica (SAIC).; 2023

Ovulation has been described as a localized inflammatory-like reaction. During this, glucocorticoids, through its receptor (i.e., the glucocorticoid receptor (GR)), increase in the follicular microenvironment to limit the inflammatory process. Here we aimed to evaluate GR expression in the preovulatory follicle and effector mechanisms related to its activation in inflammatory pathways both in the preovulatory follicle and in peripheral blood mononuclear cells (PBMC) of cows treated with adrenocorticotropin (ACTH). To this end, 100 IU of ACTH (AG; n=7) was administered to Holstein cows every 12 hours for 4 days before ovulation when ovariectomy was performed. Control group (CG; n=5) received saline solution. Previous to ovariectomy, blood samples were taken to isolate PBMC. In ovaries, GR, nuclear factor κB inhibitor-α (NFκBIα), interleukin (IL) 6, tumor necrosis factor α (TNFα) and IL1 system (IL1α, IL1β, IL1R2) expression was evaluated by immunohistochemistry along with GR/NFκB coexpression. Also, IL4 and TNFα production was analyzed by flow cytometry after exposing PBMC to autologous follicular fluid. Statistical analysis was performed using t-student’s test. In the AG, GR nuclear expression resulted to be lower in theca cells (p