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; DIAZ PU; ORTEGA HH; SALVETTINR NR; AMWEG AN

Mar del Plata

Congreso; LXVIII REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIÓN CLÍNICA (SAIC); 2023

Sociedad Argentina de Investigación Clínica

Ovulation has been described as a localized inflammatory-like reaction.During this, glucocorticoids, through its receptor (i.e., the glucocorticoidreceptor (GR)), increase in the follicular microenvironmentto limit the inflammatory process. Here we aimed to evaluateGR expression in the preovulatory follicle and effector mechanismsrelated to its activation in inflammatory pathways both in the preovulatoryfollicle and in peripheral blood mononuclear cells (PBMC)of cows treated with adrenocorticotropin (ACTH). To this end, 100IU of ACTH (AG; n=7) was administered to Holstein cows every 12hours 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, tumornecrosis factor α (TNFα) and IL1 system (IL1α, IL1β, IL1R2) expressionwas evaluated by immunohistochemistry along with GR/NFκB coexpression. Also, IL4 and TNFα production was analyzedby 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