Reprogramming refers to the regression of a specialized cell to a simpler state, resulting in cells with stem-like properties, or the direct reprogramming of one specialized cell type into another. The process of cells regressing to a stem-like state occurs naturally, mostly for repair and regeneration in aged or damaged tissues, being also known as dedifferentiation. Reprogramming can be artificially induced using a combination of transcription factors and/or chemical reagents. This was first demonstrated by Takahashi and Yamanaka in 2006. They reprogrammed mouse fibroblasts into cells having embryonic stem cell-like properties by the introduction of the transcription factors Oct3/4, Sox2, c-Myc and KIf4, using viral vectors; the resulting cells were designated induced pluripotent stem cells, or iPSCs.
The use of transcription factors in the reprogramming of cells, however, is not only inefficient but is also associated with a risk of introducing genetic mutations when inserting a transgene into the target cell's genome. Subsequent research has shown that transcription factors can be replaced with various chemical reagents in the generation of iPSCs. The use of chemicals to reprogram cells reduces the potential for introducing genetic mutations into the cells, as well as lowering the risk of tumor formation. It can also improve the efficiency of reprogramming.
iPSCs are valuable in biomedical research as they are pluripotent and can therefore theoretically be turned into any cell type. As such they have potential in drug screening and toxicity testing. They are also likely to be of use in regenerative medicine, to repair damaged tissue, or in organ transplantation to generate human organ tissues. The use of iPSCs in medicine has the advantage that the cells are autologous (self), limiting the risk of immune rejection and eliminating the need for embryonic stem cells.
Functionally mature cells may also be reprogrammed directly into a different specialized cell type without passing through the iPSC state, a process that is known as direct lineage reprogramming. This process also occurs naturally and is known as transdifferentiation.View all products for Reprogramming »
Literature for Reprogramming
Written by Kirsty E. Clarke, Victoria B. Christie, Andy Whiting and Stefan A. Przyborski, this review provides an overview of the use of small molecules in the control of stem cell growth and differentiation. Key signaling pathways are highlighted, and the regulation of ES cell self-renewal and somatic cell reprogramming is discussed. Compounds available from Tocris are listed.Request copy | Download PDF | View all reviews