Peering into the Black Box of Reprogramming to the Pluripotent State

Abstract

Somatic cells can be de-differentiated and acquire the properties of pluripotent cells by the overexpression of a small set of proteins. This process has revolutionized not only the prospect of using pluripotent cells for therapeutic purposes but also our understanding of the maintenance of cell fate. Delineating the mechanism of reprogramming has been challenging because of the low efficiency of the process and variable latency in the conversion of somatic cells to the induced pluripotent stem cell state. Prospective isolation of cells undergoing faithful reprogramming has not been possible. In this review we focus on advances made in the past year, which include proteomics and single cell transcriptomics of cells undergoing reprogramming. These studies have revealed the timing of major transcriptional and phenotypic changes, barriers to the process at early and intermediate stages and the hierarchical activation of the pluripotency network.