Enhancement of Transgene Expression by HDAC Inhibitors in Mouse Embryonic Stem Cells

Effect of the Histone Deacetylases Inhibitors on the Differentiation of Stem Cells in Bone Damage Repairing and Regeneration

Tissue damage repairing and regeneration is a research hot topic. Tissue engineering arises at the historic moment which is a defect repair compound composed of seed cells, tissue engineering scaffolds, and inducing factors. Stem cells have a limited growth period in vitro culture, and they have a pattern of replicating ageing, and these disadvantages are limiting the applications of stem cells in basic research and clinical treatment. The enhancement of stem cell differentiation ability is a difficult problem to overcome, and it is possible to enhance the differentiation ability of stem cells through histone modification so as to provide a more robust foundation for damage repairing and regeneration. Studies have shown that Histone Deacetylases (HDAC) inhibitors can improve mesenchymal stem cells in vitro induced in different directions, conversion efficiency, increasing the feasibility and safety of stem cell therapy and tissue engineering, to offer reference to promote the stem cell therapy in clinical application. Therefore, this paper mainly focusing on the usage and achievements of the deacetylase inhibitors in stem cell differentiation studies and their use and prospects in repair of bone tissue defects.

Enhancement of transgene expression by nuclear transcription factor Y and CCCTC-binding factor

If a transgene is effectively delivered to a cell, its expression may still be limited by epigenetic mechanisms that silence the transgene. Indeed, once the transgene reaches the nucleus, it may be bound by histone proteins and condensed into heterochromatin or associated with repressor proteins that block transcription. In this study, we sought to enhance transgene expression by adding binding motifs for several different epigenetic enzymes either upstream or downstream of two promoters (CMV and EF1α). Screening these plasmids revealed that luciferase expression was enhanced 10-fold (10.4 ± 5.8) by the addition of a CCAAT box just upstream of the EF1α promoter to recruit nuclear transcription factor Y (NF-Y), while inserting a CCCTC-binding factor (CTCF) motif downstream of the EF1α promoter enhanced expression at least 14-fold (14.03 ± 6.54). ChIP assays confirmed that NF-Y and CTCF bound to the motifs that were added to each plasmid, but the presence of NF-Y and CTCF did not significantly affect the levels of histone acetylation (H3K9ac) or methylation (H3K9me3). Overall, these results show that transgene expression from the EF1α promoter can be significantly increased with motifs that recruit NF-Y or CTCF. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:1581-1588, 2018.