26 HISTONE DEACETYLASE INHIBITOR SCRIPTAID IMPROVES EPIGENETIC REPROGRAMMING AND CLONING EFFICIENCY IN THE PIG

Abstract

After somatic cell nuclear transfer (SCNT), the epigenetic state of a differentiated donor cell nucleus must be reversed to the embryonic state. Incomplete epigenetic reprogramming and abnormal gene activation of the donor cell nuclei is thought to be the cause of low cloning efficiency. To improve cloning efficiency, we investigated the effect of scriptaid, a novel histone deacetylase inhibitor, on the in vitro development of porcine SCNT embryos were investigated. Cumulus cells collected from cumulus-oocyte complexes (COC) after 44 h of maturation were used for donor cell, and embryos were cultured in porcine zygote medium (PZM)-5 medium for 7 days. We found that treating SCNT embryos with 300 or 500 nM scriptaid for 20 h after activation increased developmental rate to the blastocyst stage (300 nM, 26.2%; 500 nM, 24.6% v. 100 nM, 18.3%; Ctrl, 15.7%; P < 0.05) and total cell numbers (300 nM, 43.5; 500 nM, 40.8 v. 100 nM, 33.8; Ctrl, 32.3; P < 0.05). Additionally, results of the TUNEL assay indicated that scriptaid decreased apoptosis (300 nM, 6.8% v. Ctrl, 11.4%; P < 0.05) in SCNT blastocysts. After the 300 nM scriptaid treatment, the levels of acetylated histone H3 lysine 9 and 5-hydroxymethylcytosines were increased (P < 0.05), and histone H3 lysine 9 trimethylation and 5-methylcytosine were decreased at the 1-cell stage, which might explain the enhanced (P < 0.05) transcript levels of mir-152, Oct4, Cdx2, and Bcl-xL and reduced (P < 0.05) transcription of Dnmt1, Casp3, and Bax in blastocysts. In conclusion, scriptaid enhances the developmental capacity by preventing apoptosis, and improves nuclear reprogramming in porcine SCNT embryos.This work was supported by the Bio-industry Technology Development Program, Ministry of Agriculture, Food and Rural Affairs, Republic of Korea, and by a grant from the Next-Generation BioGreen 21 Program (No. PJ009601 and PJ009098), Rural Development Administration, Republic of Korea.