Publication
Title
Alpha-linolenic acid protects the developmental capacity of bovine cumulus-oocyte complexes matured under lipotoxic conditions in vitro
Author
Abstract
Elevated concentrations of free fatty acids (FFAs), predominantly palmitic, stearic, and oleic acids (PSO), exert detrimental effects on oocyte developmental competence. This study examined the effects of omega-3 alpha-linolenic acid (ALA) during in vitro oocyte maturation (IVM) in the presence of PSO on subsequent embryo development and quality, and the cellular mechanisms that might be involved. Bovine cumulus-oocyte complexes (COCs) were supplemented during IVM with ALA (50 mu M), PSO (425 mu M), or PSO+ALA. Compared with FFA-free controls (P < 0.05), PSO increased embryo fragmentation and decreased good quality embryos on day 2 postfertilization. Day 7 blastocyst rate was also reduced. Day 8 blastocysts had lower cell counts and higher apoptosis but normal metabolic profile. In the PSO group, cumulus cell (CC) expansion was inhibited with an increased CC apoptosis while COC metabolism was not affected. Mitochondrial inner membrane potential (MMP; JC-1 staining) was reduced in the CCs and oocytes. Heat shock protein 70 (HSP70) but not glucose-regulated protein 78 kDa (GRP78, known as BiP; an endoplasmic reticulum stress marker) was upregulated in the CCs. Higher reactive oxygen species levels (DCHFDA staining) were detected in the oocytes. In contrast, adding ALA in the presence of PSO normalized embryo fragmentation, cleavage, blastocyst rates, and blastocyst quality compared to controls (P > 0.05). Combined treatment with ALA also reduced CC apoptosis, partially recovered CC expansion, abrogated the reduction in MMP in the CCs but not in the oocytes, and reduced BiP and HSP70 expression in CCs, compared with PSO only (P < 0.05). In conclusion, ALA supplementation protected oocyte developmental capacity under lipotoxic conditions mainly by protecting cumulus cell viability. Summary Sentence Alpha-linolenic acid protects cumulus cell viability and oocyte quality during in vitro maturation under lipotoxic conditions, which results in an improvement of early embryo quality and blastocyst development.
Language
English
Source (journal)
Biology of reproduction. - Champaign, Ill.
Publication
Champaign, Ill. : 2017
ISSN
0006-3363
DOI
10.1093/BIOLRE/IOX046
Volume/pages
96 :6 (2017) , p. 1181-1196
ISI
000408260000007
Pubmed ID
28520897
Full text (Publisher's DOI)
Full text (open access)
UAntwerpen
Faculty/Department
Research group
Project info
Pathways to subfertility: elevated non-esterified fatty acid concentrations as the causative link between maternal metabolic disorders and reduced embryo quality.
Mitochondria take centre stage: pathways to reduced oocyte quality and opportunities for curative strategies under maternal metabolic stress conditions.
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identifier
Creation 03.10.2017
Last edited 09.10.2023
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