Oral propylene glycol modifies follicular fluid and gene expression profiles in cumulus–oocyte complexes and embryos in feed-restricted heifers

Abstract

Dietary supplementation with propylene glycol (PG) increases in vitro production of high-quality embryos in feed-restricted heifers. The aim of the present study was to evaluate the effects of PG in feed-restricted heifers on follicular fluid insulin and insulin-like growth factor (IGF) 1 concentrations, expression of IGF system genes in oocytes and cumulus cells and the expression of selected genes in blastocysts. Feed-restricted (R) heifers were drenched with water or PG during induced oestrous cycles (400mL of PG or water/drench, daily drenching at 1600 hours for the first 9 days of the oestrous cycle). Ovum pick-up (OPU) was performed after superovulation to produce in vitro embryos and without superovulation to recover oocytes, cumulus cells and follicular fluid. OPU was also performed in a control group (not feed restricted and no drenching). Follicular fluid IGF1 concentrations were reduced by R, and PG restored IGF1 concentrations to those seen in the control group. In cumulus cells, expression of IGF1, IGF1 receptor (IGF1R) and IGF binding protein 4 (IGFBP4) was decreased in the R group, and fully (IGF1 and IGF1R) or partially (IGFBP4) restored to control levels by PG. Blastocyst perilipin 2 (PLIN2; also known as adipophilin), Bcl-2-associated X protein (BAX), SCL2A1 (facilitated glucose/fructose transporter GLUT1), aquaporin 3 (AQP3), DNA (cytosine-5)-methyltransferase 3A (DNMT3A) and heat shock 70-kDa protein 9 (HSPA9B) expression were decreased in R heifers; PG restored the expression of the last four genes to control levels. In conclusion, these results suggest that, during follicular growth, PG exerts epigenetic regulatory effects on gene expression in blastocyst stage embryos.

Effect of the Strategic Supplementation for Producing Embryos of Native Hartón del Valle Heifers

“…Results of the current study agree with Gamarra et al (2018), who observed a strong positive relationship among circulating levels of Anti-Müllerian Hormone (AMH) and in vivo embryo production after superovulation in cattle. In this regard, nutritional factors, which can be balanced by supplementation, seem to influence plasma AMH levels (Souza et al, 2015;Baruselli et al, 2011), which positively influences on the number of excellent quality embryos in embryo transfer programs.…”

Use of pregnancy‐associated plasma protein‐A during oocyte in vitro maturation increases IGF‐1 and affects the transcriptional profile of cumulus cells and embryos from Nelore cows

“…However, it is important to note that bovine oocytes do not show IGF-1 expression, only the IGF-1 receptor was identified in this cell type (Armstrong, Baxter, Hogg, & Woad, 2002;Gamarra et al, 2018).…”

“…The IGF system comprises IGF‐1 and IGF‐2, their cognate receptors, IGF‐1R and IGF‐2R, IGF binding proteins (IGFBPs) and pregnancy‐associated plasma protein‐A (PAPP‐A), which modulate IGF action in reproductive tissues (Kane, Morgan, & Coonan, ; Mazerbourg & Monget, ). However, it is important to note that bovine oocytes do not show IGF‐1 expression, only the IGF‐1 receptor was identified in this cell type (Armstrong, Baxter, Hogg, & Woad, ; Gamarra et al, ).…”

Nutritional Strategies to Promote Bovine Oocyte Quality for In Vitro Embryo Production: Do They Really Work?

“…Further research with this OPU-IVEP model indicated that propylene glycol restored IGF-1 levels in follicular fluid induced by feed restriction, and normalised cumulus cell gene expression of IGF-1, IGF-1 receptor, and IGF binding protein 4 to levels found in well-fed controls. Furthermore, in vitro-produced blastocysts from propylene glycol-treated heifers displayed an increased expression of genes downregulated by feed restriction, including genes involved in energy metabolism (SCL2A1) and membrane permeability (AQP3) [93]. Similarly, the infusion of propylene glycol twice a day for 5 days increased the in vitro blastocyst production of Holstein cows during early lactation [94] and during their lactation peak [95].…”