Exposure to non-esterified fatty acids in vitro results in changes in the ovarian and follicular environment in cattle

• Published in: Animal reproduction science Vol. 238; p. 106937
• Main Authors: Pedroza, Gabriela H., Lanzon, Lawrence F., Rabaglino, Maria B., Walker, Wendy L., Vahmani, Payam, Denicol, Anna C.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-03-2022
• Subjects: Animals; Cattle; Cow; Fatty acid; Fatty Acids, Nonesterified - metabolism; Female; Fertility; Granulosa Cells - metabolism; NEFA; Oocytes - physiology; Oogenesis; Ovary; Ovary - metabolism; Preantral follicle; Ovary; Cow; Fertility; NEFA; Fatty acid; Preantral follicle
• ISSN: 0378-4320; 1873-2232
• DOI: 10.1016/j.anireprosci.2022.106937

Negative energy balance (NEB) in the postpartum period of dairy cows is associated with reduced fertility to insemination later in lactation. We hypothesized that elevated non-esterified fatty acids (NEFA) levels that occur during NEB result in accumulation of fatty acids within the ovarian tissue and preantral follicles, causing changes in ovarian gene expression that would indicate a response to injury. We performed ovarian cortex culture and oocyte maturation in medium containing a combination of palmitic, oleic and stearic acid (NEFA). Ovarian cortex was subjected to RNA sequencing and lipid content analysis via Nile Red staining and gas chromatography; oocytes were analyzed for maturation rate and mitochondrial mass and localization following in vitro maturation (IVM). Accumulation of lipids associated with the plasma membrane was increased in granulosa cells of preantral follicles exposed to NEFA in vitro; RNA sequencing revealed changes in biological functions associated with metabolic disease, stimulation of an inflammatory response, and reduction in glucose uptake. Oocyte maturation under high NEFA compromised nuclear, but not cytoplasmic maturation. These data demonstrate that exposure to NEFA in vitro affects the ovary, preantral follicles and cumulus-oocyte complexes, and provides further insight into the potential links between metabolic imbalance and infertility.
•Exposure of ovarian cortex to levels of NEFA equivalent to negative energy balance increased lipids associated with the membrane of follicles.•Palmitic acid was elevated in the ovarian cortical tissue exposed to NEFA in vitro.•Transcriptomic changes in the ovarian cortex after exposure to NEFA were associated with an inflammatory response.