Chronic psychosocial stress affects insulin-like growth factor 1 and its receptors in mouse ovaries

Abstract

Context Chronic psychosocial stress negatively affects folliculogenesis and oogenesis. Intraovarian mechanisms mediating these effects are poorly understood. Aims This work aimed to find out how chronic psychosocial stress affects ovarian IGF1 and its receptor (IGF1R), as well as Igf1 and Igf1r gene expression in cumulus–oocyte complexes (COCs). It also aimed to address possible protective effects of gonadotropin stimulation on IGF1 ovarian signalling. Methods Female CD1 mice experienced chronic psychosocial stress of 11-day isolation followed by overcrowding for 10 days. To verify the model, blood corticosterone levels and the quality of oocytes were evaluated in stressed females. The levels of IGF1/IGF1R, blood IGF1 concentration, and expression of Igf1/Igf1r in the ovaries were compared in stressed and unstressed females. Key results Psychosocial stress caused an elevation of corticosterone level, which was alleviated by gonadotropin treatment. The stressed mice showed a decreased IGF1 level in the ovaries and a decreased expression of Igf1 and Igf1r in COCs. In the unstressed females, gonadotropin injection decreased the expression of Igf1 and Igf1r; in the stressed females, the same treatment increased Igf1r expression. Neither stress nor ovarian stimulation with gonadotropins affected the serum IGF1 level. Conclusions Psychosocial stress suppresses IGF1 signalling in the ovaries. Gonadotropin treatment modulates these effects differently in stressed and unstressed animals. Implications The results may have translational value for human reproduction. Ovarian IGF1 can be considered a candidate for further improvement of IVF results in women under conditions of chronic stress.