Increased recruitment of granulocytes in the ovaries of dairy cows with cystic ovarian disease (COD)

STASSI AF; ETCHEVERS L; ACOSTA V; VILLALBA L; CAINELLI S; SALVETTI NR; REY F; ORTEGA HH

Mar del Plata

Congreso; Reunión Anual de Sociedades de Biociencias; 2022

COD is among the most relevantcause of subfertility in dairy cattle and is the result of ovulation failure.Ovulation has been characterized as an inflammatory process in whichgranulocytes are involved. Therefore, the aim of this study was to evaluate thedistribution of granulocytes (CH138+) in ovaries of animals with spontaneous CODand control (C) animals. Ovariectomy was performed in animals with COD toobtain ovaries (n = 5), also control cows were ovariectomized in proestrus (n =5). CH138+ cells were evaluated through immunohistochemistry in total ovary(TO), in ovarian cortex (OC), medulla (OM), theca interna (TI) and externa (TE)of cysts and dominant follicles. In addition, CH138+ cells were evaluated by immunocytochemistryperformed on samples of follicular fluid from (FF) cysts and dominantfollicles. The specificity of the antibody was corroborated by western blot(WB). The data was analyzed using ANOVA with Duncan’s post-test and T-studenttest. WB analysis detected a strong positive band of 17 KDa for CH138.Comparison between groups showed that, the number of CH138+ cells was higher inTO, OM and TE of COD group than in C group (p<0.05). The analysis withingroup showed that, CH138+ cells in the C group were lower in TI and TE than OCand OM (p<0.05). CH138+ cells in the COD group were lower in TI than TE, OCand OM (p<0.05). Finally, CH138+ cells in FF of the COD group were similarto the C group (p>0.05). This is the first description about the evaluationof granulocytes in FF in cattle with COD. Growing evidence indicates thatinfiltrated leukocytes, such as granulocytes, produce additional cytokines andchemokines, acting as in situ modulators of ovarian function. These resultsdemonstrate that the immune system and inflammatory pathways are strongly involvedin ovarian events related to this disease. Therefore, we propose that this highproportion of these cells could be related to the anovulation observed in COD.