Combination of S‐adenosylhomocysteine and scriptaid, a non‐toxic epigenetic modifying reagent, modulates the reprogramming of bovine somatic‐cell nuclear transfer embryos

Abstract

The goal of this study was to improve the development of bovine somatic-cell nuclear transfer (SCNT) embryos by optimizing the combination of DNA methyltransferases inhibitor S-adenosylhomocysteine (SAH) and histone deacetylase inhibitor Scriptaid (SPD). A. 4 × 4-factor design of different drug combinations (0, 0.75, 1.0, and 1.5 mM SAH and 0, 5, 250, and 500 nM SPD) was used to identify an optimal combination of 0.75 mM SAH and 250 nM SPD that improved the developmental competence of bovine SCNT embryos. Further experiments using this combination revealed that methylation levels of CpG islands near exon 1 of the pluripotent gene SOX2; the epigenetic-related gene HDAC3 and DNMT3a; imprinted genes XIST and PEG3; as well as apoptosis-related genes BCL2 and BAX were returned to levels similar to those of in vitro fertilized (IVF) embryo after treatment, which also normalized transcript levels for these genes. This combination also returned global DNA methylation to a normal level, correcting H4K12ac levels while enhancing H3K9ac levels. Thus, the combined application of 0.75 mM SAH and 250 nM SPD can significantly improve the reprogramming of bovine SCNT embryos by stabilizing how embryos utilize their genomes.

Buffalo Embryos Produced by Handmade Cloning from Oocytes Selected Using Brilliant Cresyl Blue Staining Have Better Developmental Competence and Quality and Are Closer to Embryos Produced byIn VitroFertilization in Terms of Their Epigenetic Status and Gene Expression Pattern

“…We found that the expression level of these three pluripotency-related genes, which are expressed mainly in the ICM of blastocysts, was lower and that of two trophectoderm lineagespecific genes GATA2 and CDX2 was higher in the cloned than in IVF blastocysts. This agrees with the report of Zhang et al (2014), who found OCT4 and SOX2 transcript levels to be higher in IVF than in SCNT bovine embryos. Aberrant expression of genes during early embryonic developmental stages is believed to be an important cause of not only embryonic losses but also for fetal abnormalities that continue during gestation and parturition resulting in abnormal offspring syndrome (Arnold et al, 2008;Walker et al, 1996).…”

Early Cleavage of Handmade Cloned Buffalo (Bubalus bubalis) Embryos is an Indicator of Their Developmental Competence and Quality

“…This suggests that the level of aberrant expression of genes is higher in the late cleaving embryos as the expression level of CDX2 is higher (personal data) and that of SOX2 lower (Zhang et al. ) in IVF than in SCNT embryos. Aberrant expression of genes during early embryonic developmental stages is believed to be an important cause of not only embryonic losses but also for foetal abnormalities that continue during gestation and parturition resulting in abnormal offspring syndrome (Walker et al.…”

Procaine and S-Adenosyl-l-Homocysteine Affect the Expression of Genes Related to the Epigenetic Machinery and Change the DNA Methylation Status ofIn VitroCultured Bovine Skin Fibroblasts

“…Studies have reported that embryo development can be improved by reducing DNMT expression using epigenetic modifier agents and siRNA technology (Song et al, 2017). It has also been found that SCNT embryo development can be significantly improved by strategies that stimulate changes in DNA methylation and histone modifications, such as the use of 5-Aza-2-deoxycytidine (ZdC) (Christman, 2002;Patra and Bettuzzi, 2009;Tsuji et al, 2009), procaine (para-aminobenzoyl-diethylamino-ethanol) (Villar-Garea et al, 2003;Li et al, 2018), S-adenosyl-l-homocysteine (SAH) ( Jeon et al, 2008;Zhang et al, 2014), and scriptaid (Zhang et al, 2014), during cell culture. Procaine and SAH do not incorporate into the DNA molecule, distinguishing them from most previously tested compounds (Villar-Garea et al, 2003;Tada et al, 2007;Jafari et al, 2011).…”