Modified expression of BMP receptor 1B (BMPR1B) during bovine cystic ovarian disease development

LEIVA CJM; CATTANEO L; DÍAZ PU; REY F; GAREIS NC; SALVETTI NR; BÉRTOLI JG; ORTEGA HH

Mar del Plata

Congreso; Reunión anual de SAIC, SAI, SAFE; 2016

Follicular persistence and COD are causes of reproductive alterations in dairy cattle. In the ovary the bone morphogenetic proteins (BMPs) are expressed in granulosacells (GC) and theca cells (TC), and have important actions during follicular development through binding to a high affinity heterotetrameric complex of type I and type II receptors. Our objective was to study the immunolocalization of BMP receptor1B (BMPR1B) in the ovaries of healthy cows and animals with spontaneous or ACTH induced COD. In addition, we evaluated the expression of BMPR1B in an experimental model of follicular persistence induced by low levels ofprogesterone. In all groups we determined the expression of BMPR1B by indirect immunohistochemistry and digital image analysis in different follicular categories. We observed differences in the CG of small preantral follicles, with higher expression in the ACTH-induced and spontaneous COD groups than in the control group (p<0.05). Comparison of cysts with reference structures (small and large antral follicles) from the control group showed that ACTH-induced and spontaneous cysts presented higher BMPR1B expression than small antral follicles from the control group (p<0.05). In theca cells, BMPR1B expression was higher in atretic follicles from the ACTH-induced group than in those from the spontaneous COD group (p<0.05), without differences with the control group (p<0.05). Comparison between control and progesterone-induced persistence groups for each follicular category showed higher BMPR1B expression in granulosa cells of atretic follicles of groups with 5 and 15 days of follicular persistence than in those of the control group (p<0. 05). These results suggest that changes in the expression of BMPR1B can lead to an alteration in ovarian response to BMPs and thus contribute to the pathogenesis of ovarian alterations as follicular persistence and COD.