Generation of Induced Pluripotent Stem (iPS) Cells: Viral Vs. Non-Viral Methods

Since the first generation of induced pluripotent stem (iPS) cells was produced by Yamanaka group in 2006, a great deal of research progress has been made in this area. IPS cells have been successfully generated from fibroblasts of mouse, rat, monkey and human, including patients with various diseases, such as amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), Parkinson's disease, and diabetes. Depending on the biological properties of cells that are used to generate iPS cells, the genes encoding four transcription factors, Oct3/4, Sox2, Klf4, and c-Myc, can be reduced to one factor. Virus (retrovirus, lentivirus and adenovirus) mediated gene delivery, the most widely used method for iPS cells generation, is efficient but safety issues may hamper their clinical applications. Non-viral methods are promising alternate approaches, however, only three research groups so far have successfully produced iPS cells via nonvrial gene delivery of a single plasmid that expressing four transcription factors, Oct3/4, Sox2, Klf4, and c-Myc.

In this study, we explored the generation of iPS cells from mouse embryonic fibroblast cells and mouse neural stem cells via nonviral delivery of the plasmid expressing four transcription factors, Oct3/4, Sox2, Klf4, and c-Myc, and only Oct4 respectively. Several electroporation methods were used in this work. The effects of the sizes of the gene on the transfection efficiency were investigated via real time PCR and fluorescence microscopy. The reprogramming efficiencies of non-viral delivery methods were compared with that of the viral method. -->