75 Expression of lipid metabolism-related genes in bovine embryos cultured in vitro with diacylglycerol acyltransferase-1 inhibitor
K. Cañón-Beltrán A , J. Giraldo-Giraldo A B , Y. N. Cajas A , N. Vásquez B , C. L. V. Leal A C , A. Gutiérrez-Adán A , M. E. González D and D. Rizos AA Department of Animal Reproduction, National Institute for Agriculture and Food Research and Technology (INIA), Madrid, Spain;
B Reproductive Biotechnology Laboratory, School of Biosciences, Science Faculty, National University of Colombia, Medellín, Colombia;
C Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering, University of São Paulo, Pirassununga, Brazil;
D Department of Anatomy and Embryology, Veterinary Faculty, Complutense University of Madrid (UCM), Madrid, Spain
Reproduction, Fertility and Development 32(2) 163-164 https://doi.org/10.1071/RDv32n2Ab75
Published: 2 December 2019
Abstract
Intracellular lipids accumulated in embryos produced in vitro have been linked to reductions in both quality and post-cryopreservation viability. Diacylglycerol O-acyltransferase 1 (DGAT1) is an enzyme that catalyzes the final step in triglyceride synthesis, which is a major component of the lipid droplets in embryos. Thus, the aim of this study was to evaluate the development and quality, in regard to changes in the expression of candidate genes of lipid metabolism, of bovine blastocysts cultured in vitro with DGAT1 inhibitor (A922500 Sigma-Aldrich). Zygotes were cultured in synthetic oviduct fluid supplemented with 5% FCS (TC) or in TC supplemented with 10 or 50 µM DGAT1 inhibitor (T10 and T50, respectively) or TC with 0.1% dimethyl sulfoxide (TDMSO: vehicle for DGAT1 dilution) from 54 h post-insemination (hpi; major embryonic genome activation, EGA) until Day 8. Cleavage rate (48 hpi) and blastocyst yield (Day 7-8) were evaluated. Day 7 blastocysts were snap-frozen in LN2 for gene expression analysis. The mRNA abundance of candidate genes related to lipid metabolism (DGAT1, PLIN2, GLUT5, GLUT1, GPX1, PPAR1b, and G6PD) was measured by quantitative PCR. The H2AFZ and ACTB genes were used as housekeeping genes. Statistical analysis was assessed by one-way analysis of variance. No differences were found in cleavage rate, whereas blastocyst yield at Day 8 was higher (P < 0.05) for T50 (30.5 ± 0.5%) and TC (29.7 ± 0.5%) compared with T10 (25.6 ± 0.5%) and TDMSO (27.1 ± 0.8%). The expression of genes regulating lipid droplet formation (DGAT1 and PLIN2) was down-regulated in embryos of T10 and T50 groups compared with controls (P < 0.05) only for DGAT1, whereas no differences were observed for PLIN2. The expression of GLUT5, a fructose metabolism transporter gene, was only increased in embryos in the T10 group, whereas the relative abundance of GLUT1 (involved in glucose metabolism) was up-regulated in T10 and T50 groups compared with controls (P < 0.05). The GPX1 gene was decreased significantly in embryos from both DGAT1-inhibitor groups compared with the controls. The expression profile of PPAR1b and G6PD, lipid metabolism-regulating genes, were not different among embryo groups. In conclusion, supplementation of embryo culture with DGAT1 inhibitor improves development and blastocyst quality in terms of the expression of lipid metabolism-regulating genes, supporting a relationship between lipid metabolism and embryo feature.
Funding was provided by MINECO-Spain AGL2015-70140-R & RTI2018-093548-B-I00; J. Giraldo-Giraldo COLCIENCIAS 727/2015-Colombia; Y. N. Cajas, SENESCYT-Ecuador; C. L. V. Leal, FAPESP-Brasil 2017/20339-3.
