Generation of Induced Pluripotent Stem (iPS) Cells by Nuclear Reprogramming
Figure 1
A simplified version of reprogramming of adult cells to pluripotent cells by 4 factors. (a) Any adult source of cells like epithelial, muscle, fibroblast, and adipose cells is isolated and cultured in appropriate medium. Then cells are transfected, nucleofected, or transduced by 4 reprogramming factors. These factors may be Oct3/4, Sox2, Nanog, and Klf4/c-Myc. The reprogramming paths are not well understood yet, requiring expression of several genes as well as epigenetic modification of the genome. (b) Reprogramming factors (transcription factor genes) can be delivered by various methods. In case of viral gene delivery, genes are integrated with the host chromosome randomly. Methods of gene deliveries like plasmids, mRNAs, proteins, genes are expressed transiently and diminished the expression with the concomitant increase in expression of pluripotent markers.
