Direct reprogramming of adult cells: avoiding the pluripotent state

Abstract

The procedure of using mature, fully differentiated cells and inducing them toward other cell types while bypassing an intermediate pluripotent state is termed direct reprogramming. Avoiding the pluripotent stage during cellular conversions can be achieved either through ectopic expression of lineage-specific factors (transdifferentiation) or a direct reprogramming process that involves partial reprogramming toward the pluripotent stage. Latest advances in the field seek to alleviate concerns that include teratoma formation or retroviral usage when it comes to delivering reprogramming factors to cells. They also seek to improve efficacy and efficiency of cellular conversion, both in vitro and in vivo. The final products of this reprogramming approach could be then directly implemented in regenerative and personalized medicine.

Keywords: ESCs; PiPS; iPS; miRNA; reprogramming; transdifferentiation.

Figure 1

Schematic diagram showing reprogramming of fibroblasts to induced pluripotent stem cells followed by differentiation, direct reprogramming of fibroblasts with four factors generating Partial-iPS cells, and direct conversion. Abbreviations: c-MYC, c-myelocytomatosis oncogene; Klf4, Kruppel-like factor 4; Oct4, octamer-binding protein; Sox2, sex determining region Y-box containing gene 2.