Generation of human induced pluripotent stem cells by direct delivery of reprogramming proteins.

摘要

To date, all methods to generate induced pluripotent stem cells (iPSCs) require the use of genetic materials and/or potentially mutagenic molecules. Here we report the generation of stable iPSCs from human fibroblasts by directly delivering four re-programming proteins (Oct4, Sox2, Klf4, and c-Myc) fused with a cell-penetrating peptide (CPP). These protein-induced human iPSCs (p-hiPSCs) exhibited similarity to human embryonic stem cells (hESCs) in morphology, proliferation, and expression of characteristic pluripotency markers. p-hiPSC lines produced with these recombinant proteins were successfully maintained for more than 35 passages and differentiated into derivatives of all three embryonic germ layers both in vitro and in teratomas. This system eliminates the potential risks associated with the use of viruses, DNA transfection, and potentially harmful chemicals and in the future could potentially provide a safe source of patient-specific cells for regenerative medicine.