Epigenetic modification mechanisms are activated by reactive oxygen (ro) in bovine induced pluripotent stem cells

Abstract

The induced pluripotent stem cells (iPSCs) emerged as new biotechnology in 2006 when Takahashi and Yamanaka reprogrammed murine fibroblasts using only the expression of four exogenous factors: Oct4, Sox2, Klf-4 and c-Myc (OSKM). Since then, several reprogramming methodologies for the generation of iPSCs have been developed, especially in non-integrative systems for clinical application to be feasible. However, in the reprogramming protocols, there is still a low conversion rate, only 0.01 to 0.1%, of differentiated cells for iPSCs, with epigenetic reprogramming being one of the contributors to this low index. It is an often incomplete process that affects the ability of reprogramming, pluripotentiality and differentiation of the iPSCs. It is known that the modulation of the amount of cellular reactive oxygen (RO) is able to modify the epigenetic marks, we suggest then that the oxygen tension used for the culture can modulate the amount of RO, and consequently affect the epigenetic markings, even in imprinted genes, possibly influencing the reprogramming efficiency. We aim to analyze if there is a difference in RO during culture in different conditions and if the epigenetic marks are affected with the culture in low oxygen tension. We will use a group cultured in an atmosphere of 20% O2 and another 5% O2, to perform a characterization and evaluation of the modulation in relation to SOD2 (mitochondrial), H3K9me3 (epigenetic) and H19 / IGF2 (imprinted gene).