Modulation of long-chain Acyl-CoA synthetase on the development, lipid deposit and cryosurvival of in vitro produced bovine embryos

Abstract

In this study, we evaluated the modulation effect of long-chain Acyl-CoA synthetase during early embryo development. Bovine embryos were cultured in four groups: positive modulation (ACS+) with GW3965 hydrochloride, negative modulation (ACS-) with Triacsin C, association of both modulators (ACS±), and control. Embryo development rates were not altered (P>0.05) by treatments. Embryonic cytoplasmic lipid content increased in ACS+ but reduced in ACS- compared to the control (P < 0.05), whereas the membrane phospholipids profile was not altered by treatments. The total number of blastomeres did not differ (P > 0.05) between groups; however, an increased apoptotic cells percentage was found in ACS- compared to control. Twenty-four hours after warming, ACS+ and control grade I embryos presented the best hatching rates, whereas the ACS+ group equaled the hatching rates between their embryos of grades I, II and III 48 hours after warming. The relative abundance of transcripts for genes associated with lipid metabolism ( ACSL3 , ACSL6 , ACAT1 , SCD , and AUH ), heatshock ( HSP90AA1 and HSF1 ), oxidative stress ( GPX4 ), and angiogenesis ( VEGF ), among other important genes for embryo development were affected by at least one of the treatments. The treatments were effective in modulating the level of transcripts for ACSL3 and the cytoplasmic lipid content. The ACS- was not effective in increasing embryonic cryosurvival, whereas ACS+ restored survival rates after vitrification of embryos with low quality, making them equivalent to embryos of excellent quality.

The Study of the Response of Fat Metabolism to Long-Term Energy Stress Based on Serum, Fatty Acid and Transcriptome Profiles in Yaks

“…Long-chain acyl-CoA synthetases (ACSLs) are the rate-limited enzymes of fatty acid activation. The expression levels of the ACSL3 ( q < 0.01) and ACSL6 genes ( q < 0.05) [ 38 ] were upregulated in the subcutaneous fat of the yaks under ES, and it was inferred that PUFA synthesis was promoted in the subcutaneous fat of the yaks under ES. The elongases of very long chain fatty acids (ELOVLs) are key rate-limiting enzymes in long-chain fatty acid biosynthesis [ 39 , 40 ], and the expression of the ELOVL7 ( q < 0.01) and ELOVL5 genes ( q < 0.05) was upregulated in the subcutaneous fat of the yaks under ES.…”

ELOVL5 Participates in Embryonic Lipid Determination of Cellular Membranes and Cytoplasmic Droplets

“…In order to perform the semi-quantitative lipid content assay, expanded blastocysts ( n = 15/group) were subjected to Sudan Black staining, as previously described [ 29 , 53 ], with minor modifications. The embryos were fixed in 4% formaldehyde solution for 2 h at room temperature, washed, and transferred to 50% ethanol drops.…”

“…Lipid profile analysis was performed as previously described [ 29 , 53 ]. Briefly, expanded blastocysts were randomly collected ( n = 15/group) to establish the lipid profiles of each experimental group.…”

Transcriptional profiling of embryo cryotolerance

“…Four rounds of in vitro embryo production were performed as described previously (Valente et al, 2019) with minor modifications. Briefly, Bos taurus (predominantly B. taurus indicus ) ovaries were obtained from a commercial slaughterhouse and stored in sterile saline (0.9% wt/vol NaCl) at 30°C for transport to the laboratory within 2 h after slaughter.…”

“…We recognize that the presence of nonviable embryos (not morphologically identified) among the LC analyzed embryos may lead to inaccurate results. To avoid this, an independent set of LC blastocysts ( N = 23) was subjected to apoptosis evaluation (as previously described; Valente et al, 2019). The cell number and apoptosis rates (mean ± SEM ) of LC blastocysts were 89.2 ± 4.6% and 32.9 ± 4.6%, respectively, and only two embryos (8.7%) exhibited apoptosis rates that were greater than 70.0%.…”