The Dynamic Transcription Profiles of Proliferating Bovine Ovarian Granulosa When Exposed to Increased Levels of β-Hydroxybutyric Acid

Abstract

Ketosis is common in high-yield dairy cows. It is a condition that is characterized by the accumulation of serum β-hydroxybutyric acid (BHBA). Both subclinical ketosis and clinical ketosis can compromise the reproductive performance and cause long-lasting negative effects on reproductive efficiency by affecting the proliferation of follicular and granulosa cells. However, the regulatory mechanisms involved in the development of follicular cells and granulosa cells in cows experiencing subclinical ketosis and clinical ketosis remain largely unknown. To investigate the effect of a ketosis-triggered increase in BHBA on bovine follicular granulosa cell development, we detected a significant reduction in the proliferation of granulosa cells (P < 0.05) in the BHBA-1.2 mM and BHBA-2.4 mM groups and a significant increase in the number of granulosa cells in the G1 phase of the cell cycle (P < 0.05). RNA-seq and trend analysis were used to identify differentially expressed genes by comparing three clusters: low-concentration response to 1.2 mM BHBA, high-concentration response to 2.4 mM BHBA, and the similar trend (up or down) response following BHBA concentration increased. GO and KEGG enrichment analyses were performed separately for each cluster. Analysis showed that two novel down-regulated genes (G0S2 and S100A6), which are associated with cell proliferation and cycle progression, were enriched in the low-concentration response to 1.2 mM BHBA. Another differentially expressed gene (PARP), which plays a role in the apoptotic pathway, was enriched in the high-concentration response to 2.4 mM BHBA. We also found that CYP27B1 and CYP17A1, which are associated with Ca2+ homeostasis and estrogen synthesis, were enriched in a similar trend response. In conclusion, we describe the dynamic transcription profiles of granulosa cells under different levels of β-hydroxybutyric stress and report key regulators that may underlie the detrimental effects on the development of follicles and granulosa cells, thus representing potential therapeutic targets to improve fertility in dairy cows with subclinical ketosis or clinical ketosis.

Sirtuin 3 regulation: a target to alleviate β-hydroxybutyric acid-induced mitochondrial dysfunction in bovine granulosa cells

“…Herein, we detected an increase in the apoptotic rate of fGCs as well as pro-apoptoticrelated proteins with increasing BHBA concentrations. Similarly, in our previous study, we identified that the differentially expressed genes were involved in apoptosis pathway after 2.4 mmol/L BHBA stress [52]. This suggests that increased concentrations of BHBA-induced apoptosis in fGCs; this may be an impaired developmental factor of follicles.…”

Effects of daily propylene glycol drenching during the Ovsynch protocol on fertility and metabolic parameters in lactating dairy cows

“…a Oral daily administration of propylene glycol (PG-OVS) or water (CON-OVS) during the Ovsynch protocol in lactating dairy cows. Gong et al, 2022;Vanholder et al, 2015). On the other hand, a decreased BHBA concentration can have a positive effect on steroid mechanisms, increasing the quality of oocytes and the ability of embryo development in dairy cows (Ospina et al, 2010;Pishvaei et al, 2021).…”

“…It is important to note that the relationship between BHBA concentrations and fertility is complex and may vary depending on the individual cow and the specific circumstances. It has been demonstrated that higher BHBA concentration impaired hypothalamic pituitary–ovarian axis, granulosa cell development, follicular steroidogenesis in granulosa cells and oocyte maturation (Butler, 2003; Gong et al, 2022; Vanholder et al, 2015). On the other hand, a decreased BHBA concentration can have a positive effect on steroid mechanisms, increasing the quality of oocytes and the ability of embryo development in dairy cows (Ospina et al, 2010; Pishvaei et al, 2021).…”

β-hydroxybutyrate impairs bovine oocyte maturation via pyruvate dehydrogenase (PDH) associated energy metabolism abnormality

“…It is caused by the accumulation of serum ketone βHB. Both subclinical ketosis and clinical ketosis can compromise reproductive performance and cause long-lasting negative effects on reproductive efficiency ( Gong et al, 2022 ). In this study, we detected the effects of βHB on mitochondria functions and energy metabolism during bovine oocyte maturation.…”