Impaired insulin signaling pathways affect ovarian steroidogenesis in cows with COD

GAREIS, N.C.; HUBER, E.; HEIN, G.J.; RODRÍGUEZ, F.M.; SALVETTI, N.R.; ANGELI, E.; ORTEGA, H.H.; REY, F.

ANIMAL REPRODUCTION SCIENCE

ELSEVIER SCIENCE BV

Año: 2018

0378-4320

Cystic ovarian disease (COD) represents an important cause ofinfertility in dairy cattle and is associated with multiple physiologicaldisorders. Steroidogenesis, which is necessary to ensure normal ovarianfunctions, involves multiple enzymatic pathways coordinated by insulin andother proteins. We have previously shown that cows with COD have an alteredinsulin response. Therefore, in the present study, we evaluated further alterationsin intermediates downstream of the PI3K pathway and pathways mediated by ERK ascritical signals for steroidogenic enzymes expression in the ovaries of controlcows and cows with spontaneous COD. To this end, we evaluated the gene andprotein expression of pan-AKT, mTOR, ERK1/2, and steroidogenic enzymes by real-timePCR and immunohistochemistry. Steroid hormone concentrations were assessed atsystemic and intrafollicular level. Results showed altered expression ofintermediate molecules of the insulin signaling pathway, whose action mightmodify the synthetic pathway of steroidogenic hormones. In this sense, theexpression of steroidogenic enzymes and the concentration of progesterone inserum and follicular fluid were altered. The alterations observed support thehypothesis that both systemic factors contribute to the development and/ormaintenance of COD, and intrafollicular factors such as metabolic hormones asinsulin exert determinant effects on ovarian functionality in cows with COD.