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

Abstract

Embryonic lipids are crucial for the formation of cellular membranes and dynamically participate in metabolic pathways. Cells can synthesize simple fatty acids, and the elongation of fatty acids facilitates the formation of complex lipids. The aim of this work was to investigate the involvement of the elongation of very long chain fatty acid enzyme 5 (ELOVL5) in embryonic development and lipid determination. Bovine embryos were produced in vitro using a standard protocol and randomly divided to receive one of three treatments at Day 4: morpholino (Mo) gene expression knockdown assay for ELOVL5 (ELOVL5-Mo), Mo antisense oligonucleotides for the thalassemic β-globulin human mRNA (technical control Mo), and placebo (biological control). The phenotypes of embryonic development, cell number, ELOVL5 protein abundance, lipid droplet deposits, and lipid fingerprint were investigated. No detrimental effects (p > 0.05) were observed on embryo development in terms of cleavage (59.4 ± 3.5%, 63.6 ± 4.1%, and 65.4 ± 2.2%), blastocyst production (31.3 ± 4.2%, 28.1 ± 4.9%, and 36.1 ± 2.1%), and blastocyst cell number (99.6 ± 7.7, 100.2 ± 6.2, 86.8 ± 5.6), respectively, for biological control, technical control Mo, and ELOVL5-Mo. ELOVL5 protein abundance and cytoplasmic lipid droplet deposition were increased (p < 0.05) in ELOVL5-Mo–derived blastocysts compared with the controls. However, seven lipid species, including phosphatidylcholines, phosphatidylethanolamines, and triacylglycerol, were downregulated in the ELOVL5-Mo–derived blastocysts compared with the biological control. Therefore, ELOVL5 is involved in the determination of embryonic lipid content and composition. Transient translational blockage of ELOVL5 reduced the expression of specific lipid species and promoted increased cytoplasmic lipid droplet deposition, but with no apparent deleterious effect on embryonic development and blastocyst cell number.

Lipid Metabolism in Bovine Oocytes and Early Embryos under In Vivo, In Vitro, and Stress Conditions

“…Another study showed an increase in cytoplasmic lipid droplet deposition after transient gene expression knockdown of ELOVL5. Interestingly, no apparent deleterious effect on embryonic development and blastocyst cell number was observed, but a reduction in the expression of specific lipid genes was observed [82], demonstrating that further studies need to be conducted to clarify how altered lipid metabolism does not interfere with embryo quality.…”

“…ACSL3 is related to the formation of LD in embryos. Similarly, elongation of very-long-chain fatty acids (ELOVL) is associated with the embryonic membrane phospholipid composition [65], and ELOVL5 modulates intracytoplasmic LD [82].…”

Changes in the Relative Abundance of miR-205, miR-26a-5p, let-7b and their Target Genes in Vitrified Bovine Embryos after Phenazine Ethosulfate Supplementation

“…The ELOVL5 plays an important role in the determination of embryonic lipid droplet content. Blockage of ELOVL5 translation revealed a clear effect on the expression of particular lipids and promoted increased deposition of cytoplasmic lipid droplet (Lanzarini et al, 2021). A previous study concluded that overexpression of ELOVL5 gene at the morula stage preceded an increased abundance of a series of lipids at the blastocyst stage (Sudano et al, 2016).…”

Global Transcriptional Profiling of Granulosa Cells from Polycystic Ovary Syndrome Patients: Comparative Analyses of Patients with or without History of Ovarian Hyperstimulation Syndrome Reveals Distinct Biomarkers and Pathways

“…Obesity and diabetes are independently associated with an altered female reproductive function [ 13 , 45 , 46 ]. Interestingly, a recent study reported that ELOVL5 is involved in embryonic development and lipid metabolism [ 47 ]. KLF2 is expressed in endothelial cells and inhibited by the inflammatory cytokine interleukin-1, hence, implicated as a novel regulator response to proinflammatory stimuli [ 48 ].…”