The endometrial expression of interleukin-1 family: their involvement in delayed conception of dairy cows

CAINELLI S.; PERALTA, M.B.; ANGELI, E.; STASSI A.F.; SALVETTI, N.R.; ORTEGA, H.H.; REY, F.; VELAZQUEZ M.M.L.

Congreso; LXVI REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIÓN CLÍNICA (SAIC); 2021

The cytokines of the interleukin-1 family are closely involved in processes such as resolution of uterine inflammation and are locallyproduced by macrophages and endometrial cells under stimuli.However, little is known about the role of these cytokines in the absence of disease during postpartum period where conception andpregnancy occur in cattle. The aim of this study was to analyse thegene and protein expression levels of the members of IL-1 family:IL-1α, IL-1β, IL-1RI, IL-1RII and IL-1RA during postpartum period,and their possible association with delayed conception.Endometrial biopsies were obtained from multiparous Holstein cows(n=16) at 45 and 60 days in milk (DIM). The voluntary waiting periodof cows was 70 days. All procedures were approved by the EthicsCommittee (FCV-UNL). The gene expression of IL-1α, IL-1β, IL-1RI,IL-1RII and IL-1RA was analyzed by real-time PCR. The immunolocalization of the cytokines was assessed by indirect immunohistochemistry.Kaplan?Meier test was used to evaluate the possible associationbetween the gene and protein levels of each cytokine and delayedconception. Then, when the results from Kaplan-Meier showed significant association, we grouped the animals like ?fewer number ofdays to conception? (FDC) and ?greater number of days to conception? (GDC) for comparison. To analyze the differential expressionlevels over time in FDC and GDC groups, a Generalized LinearModel was used considering DIM as a fixed factor. The gene expression of all members of IL-1 family showed no significant associationwith delayed conception. However, the association between the protein expression of IL-1β and IL-1RA in glandular epithelium (GE)and delayed conception was significant. Then, the GLM showed nosignificant differences in GE between 45 and 60 DIM, both in theFDC and GDC group. These results suggest a potential role of somemembers from IL-1 family, as IL-1β and IL-1RA, in the mechanismsinvolved to early conception.