Impaired insulin signaling pathway in ovarian follicles of cows with cystic ovarian disease

HEIN G; PANZANI C; RODRIGUEZ, MF; SALVETTI NR; DIAZ, PU; GAREIS N; BENITEZ, G; ORTEGA HH; REY F

ANIMAL REPRODUCTION SCIENCE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 156 p. 64 - 74

0378-4320

tCystic ovarian disease (COD) is an important cause of infertility in dairy cattle. Follicular cellsteroidogenesis and proliferation in ovulatory follicles is stimulated by hormones such asinsulin and its necessary post-receptor response. The aim of this study was to determine theexpression of insulin receptor (IR), IR substrate-1 (IRS1) and phosphatidylinositol 3-kinase(PI3K), key intermediates in the insulin pathway, in control cows and cows with sponta-neous COD and ACTH-induced COD. IR and IRS1 mRNA levels were greater in granulosacells and lower in follicular cysts than in control tertiary follicles. PI3K mRNA levels weresimilar in all follicles evaluated, whereas the expression of IR, IRS1 and PI3K was similar intheca cells. Protein expression of IR was higher in control tertiary follicles than in the samestructures in animals with COD and with cysts. IRS1 and PI3K protein expression showedthe same pattern in tertiary and cystic follicles. However, the protein expression of subunitalpha p85 of PI3K was greater in theca cells from tertiary follicles than in cystic follicles.These results provide new insights into the insulin response in cows with COD. The lowergene and protein expressions of some insulin downstream effectors at an early stage of thesignaling pathway could negatively influence the functionality of ovaries and contribute tofollicle persistence.