Chemical tagging and customizing of cellular chromatin states using ultrafast trans-splicing inteins
2015; 7 (5): 394-402
Post-translational modification of the histone proteins in chromatin plays a central role in the epigenetic control of DNA-templated processes in eukaryotic cells. Developing methods that enable the structure of histones to be manipulated is, therefore, essential to understand the biochemical mechanisms that underlie genomic regulation. Here we present a synthetic biology method to engineer histones that bear site-specific modifications on cellular chromatin using protein trans-splicing (PTS). We genetically fused the N-terminal fragment of ultrafast split intein to the C terminus of histone H2B, which, on reaction with a complementary synthetic C intein, generated labelled histone. Using this approach, we incorporated various non-native chemical modifications into chromatin in vivo with temporal control. Furthermore, the time and concentration dependence of PTS performed in nucleo enabled us to examine differences in the accessibility of the euchromatin and heterochromatin regions of the epigenome. Finally, we used PTS to semisynthesize a native histone modification, H2BK120 ubiquitination, in isolated nuclei and showed that this can trigger downstream epigenetic crosstalk of H3K79 methylation.
View details for DOI 10.1038/NCHEM.2224
View details for Web of Science ID 000353347900012
View details for PubMedID 25901817
View details for PubMedCentralID PMC4617616
Engineered Fetal Cardiac Graft Preserves Its Cardiomyocyte Proliferation Within Postinfarcted Myocardium and Sustains Cardiac Function
TISSUE ENGINEERING PART A
2011; 17 (5-6): 585-596
The goal of cellular cardiomyoplasty is to replace damaged myocardium by healthy myocardium achieved by host myocardial regeneration and/or transplantation of donor cardiomyocytes (CMs). In the case of CM transplantation, studies suggest that immature CMs may be the optimal cell type to survive and functionally integrate into damaged myocardium. In the present study, we tested the hypothesis that active proliferation of immature CMs contributes graft survival and functional recovery of recipient myocardium. We constructed engineered cardiac tissue from gestational day 14 rat fetal cardiac cells (EFCT) or day 3 neonatal cardiac cells (ENCT). Culture day 7 EFCTs or ENCTs were implanted onto the postinfarct adult left ventricle (LV). CM proliferation rate of EFCT was significantly higher than that of ENCT at 3 days and 8 weeks after the graft implantation, whereas CM apoptosis rate remained the same in both groups. Echocardiogram showed that ENCT implantation sustained LV contraction, whereas EFCT implantation significantly increased the LV contraction at 8 weeks versus sham group (p < 0.05, analysis of variance). These results suggest that active CM proliferation may play a critical role in immature donor CM survival and the functional recovery of damaged recipient myocardium.
View details for DOI 10.1089/ten.tea.2010.0259
View details for Web of Science ID 000287801600001
View details for PubMedID 20868205
View details for PubMedCentralID PMC3043979