Effect of ATM and HDAC Inhibition on Etoposide-Induced DNA Damage in Porcine Early Preimplantation Embryos

• Published in: PloS one Vol. 10; no. 11; p. e0142561
• Main Authors: Wang, HaiYang, Luo, YiBo, Lin, ZiLi, Lee, In-Won, Kwon, Jeongwoo, Cui, Xiang-Shun, Kim, Nam-Hyung
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 10.11.2015; Public Library of Science (PLoS)
• Subjects: Animal sciences; Animals; Apoptosis; Apoptosis - drug effects; Apoptosis - genetics; Ataxia; Ataxia telangiectasia mutated protein; Ataxia Telangiectasia Mutated Proteins - antagonists & inhibitors; Bax protein; Blastocyst - drug effects; Blastocyst - metabolism; Caffeine; Caffeine - pharmacology; Cell culture; Cell cycle; Cell division; Cleavage; Comparative analysis; Damage detection; Deoxyribonucleic acid; Developmental stages; DNA; DNA damage; DNA Damage - drug effects; DNA repair; Embryogenesis; Embryonic development; Embryonic Development - drug effects; Embryonic Development - genetics; Embryonic growth stage; Embryos; Enzyme inhibitors; Epigenetics; Etoposide; Etoposide - pharmacology; Female; Gene expression; Gene Expression Regulation - drug effects; Genes; Histone deacetylase; Histone Deacetylase Inhibitors - pharmacology; Homologous recombination; Homology; Inhibitors; Ionizing radiation; Kinases; Medical research; Morpholines - pharmacology; Non-homologous end joining; Oct-4 protein; Oocytes; Phosphorylation; Pluripotency; Polyvinyl alcohol; Pregnancy; Proteins; Pyrones - pharmacology; Receptors, Peptide - antagonists & inhibitors; Repair; RNA; Somatic cells; Swine; Topoisomerase II Inhibitors - pharmacology
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0142561

Oocyte maturation and embryonic development are sensitive to DNA damage. Compared with somatic cells or oocytes, little is known about the response to DNA damage in early preimplantation embryos. In this study, we examined DNA damage checkpoints and DNA repair mechanisms in parthenogenetic preimplantation porcine embryos. We found that most of the etoposide-treated embryos showed delay in cleavage and ceased development before the blastocyst stage. In DNA-damaged embryos, the earliest positive TUNEL signals were detected on Day 5 of in vitro culture. Caffeine, which is an ATM (ataxia telangiectasia mutated) and ATR (ataxia telangiectasia and Rad3-related protein) kinase inhibitor, and KU55933, which is an ATM kinase inhibitor, were equally effective in rescuing the etoposide-induced cell-cycle blocks. This indicates that ATM plays a central role in the regulation of the checkpoint mechanisms. Treating the embryos with histone deacetylase inhibitors (HDACi) increased embryonic development and reduced etoposide-induced double-strand breaks (DSBs). The mRNA expression of genes involved in non-homologous end-joining (NHEJ) or homologous recombination (HR) pathways for DSB repair was reduced upon HDACi treatment in 5-day-old embryos. Furthermore, HDACi treatment increased the expression levels of pluripotency-related genes (OCT4, SOX2 and NANOG) and decreased the expression levels of apoptosis-related genes (CASP3 and BAX). These results indicate that early embryonic cleavage and development are disturbed by etoposide-induced DNA damage. ATMi (caffeine or KU55933) treatment bypasses the checkpoint while HDACi treatment improves the efficiency of DSB repair to increase the cleavage and blastocyst rate in porcine early preimplantation embryos.