Human embryonic stem cells (hESC) and human induced pluripotent stem cels (hiPSC) differ at the epigenomic level and in their differentiation potential. This points towards differences in resetting the genome-wide pluripotent epigenetic marks and suggests a superior reprogramming capacity of the oocyte when compared to iPSC reprogramming. We investigated the capacity of STELLA (DPPA3), a protein involved in epigenetic chromatin reprogramming in the zygote, to improve hiPSC reprogramming. In the mouse, supplementation of STELLA to the classical reprogramming factors significantly enhanced reprogramming kinetics and yielded iPSC with high-grade chimera competence. In this project, we generated hiPSC lines by lentiviral transduction of BJ fibroblasts with C-MYC, KLF4, SOX2 and POU5F1 and combined this with STELLA mRNA transfection during the first four days of reprogramming. We obtained 7 control iPSC lines and 6 STELLA iPSC lines and compared their transcriptional profile to that of 5 male control hESC lines and BJ cells using whole genome RNA sequencing. Expression analysis revealed no differentially expressed genes (DEGs) between control and STELLA iPSC. When comparing the control and STELLA iPSC directly to hESC, 23 and 26 DEGs, respectively, were detected. Of these, 18 genes were overlapping between these two groups. Similarly, when comparing the hPSC groups to the BJ fibroblasts, 8041 DEGs were detected in STELLA iPSC, 8113 in control iPSC and 7490 in hESC. Of these, 6969 genes were common between STELLA iPSC and hESC, 7026 between control iPSC and hESC, and 7649 between control and STELLA iPSC. In conclusion, we observed no effect of adding STELLA to the hiPSC reprogramming cocktail at the transcriptome level. Transcriptomes of both control and STELLA iPSC are highly similar to that of hESC, but show a common iPSC-specific DEG signature.This project was sponsored by Innovation by Science and Technology in Flanders (IWT, Project Number: 150042)
In the project, we improve the iPSC quality to have the golden standard of pluripotent stem cells which is embryonic stem cells. It will result in full reprogramming iPSC cells and highest differentiation capacity cells. We will even able to differentiate these iPSCs into sperm. And safer and more precise usage of them for clinical applications including disease modeling and regenerative medicine.