Non-coding RNA Profile in Porcine Granulosa Cells in Primiparous Sows Exposed to a Severe Lactational Negative Energy Balance: Interplay Between Whole Body Metabolism and Ovarian Follicular Development

Over the last several decades, pigs have been genetically selected for lean body mass and large litters. This increases the chance that sows enter a substantial negative energy balance (NEB) during lactation because of the high demands on milk production to feed all piglets. This NEB has an adverse influence on the sows’ reproductive performance by affecting the developmental competence of the follicle pool that should give rise to the next litter. In our previous experiments we observed that follicle size was significantly reduced as were follicular and peripheral steroid levels (e.g., β-oestradiol, progestins and androgens), and insulin-like growth factor 1 (IGF1) levels in primiparous sows that experienced a severe lactational NEB.

From the literature, it is known that non-coding RNAs are involved in regulation of a variety of processes at the post-transcriptional level, including cell proliferation, apoptosis, and energy metabolism. Recently, together with our collaborator, we reported that in pigs non-coding RNAs can contribute to follicular development via involvement in ovarian steroidogenic pathways, apoptosis related pathways and oxidative stress related pathways.

Based on these observations, we hypothesize that a severe NEB in sows may affect the non-coding RNA profiles in follicular granulosa cells, the cells that are in close contact with the maturing oocyte. This may influence steroidogenesis, metabolic processes, oxidative stress, and insulin-like growth factor 1 (IGF1) regulated pathways through interfering with its target genes. IGF1 is an important regulator of follicular growth and maturation. The aim of this project is to elucidate how non-coding RNAs can affect follicular developmental competence under NEB conditions. The proposed research will to our knowledge provide new insights into the functioning of pathways target of non-coding RNAs at the interplay between female reproduction and whole-body metabolism.