An Efficient Chemical-Defined Condition for Generation of Human Induced Pluripotent Stem Cells

Abstract Background: Human induced pluripotent stem cells (hiPSCs) hold great potential in disease modeling, drug screening and cell therapy. However, efficiency and costs of hiPSCs preparation still need to be improved.Methods: We screened the compounds that target signaling pathways, epigenetic modifications or metabolic-process regulation to replace the growth factors. After small molecules treatment, TRA-1-60 staining was performed to quantify the efficiency of somatic cell reprogramming. Next, small molecule cocktail induced ESCs or iPSCs were examined with pluripotent markers expression. Finally, Genome-wide gene expression profile was then analyzed by RNA-seq to illustrate the mechanism of human somatic cell reprogramming. Result: Here, we found that a dual-specificity tyrosine phosphorylation-regulated kinase inhibitor ID-8 robustly enhanced human somatic cell reprogramming by upregulation of PDK4 and activation of glycolysis. Furthermore, we identified a novel growth-factor-free hiPSC generation system using small molecules ID-8/Kartogenin (IK). Finally, we developed IK medium combined with Low-dose bFGF to support the long-term expansion of human pluripotent stem cells. IK-iPSCs showed pluripotency and normal karyotype. Conclusions: Our studies may provide a novel growth-factor-free culture system to facilitate the generation of hiPSCs for multiple application in regenerative medicine.