Defining the Minimal Factors Required for Erythropoiesis through Direct Lineage Conversion.

Sandra Capellera-Garcia,Shamit Soneji,Johan Flygare,Mikael N.E Sommarin,Sofie Singbrant,Kishori Dhulipala,Göran Karlsson,Ángel Raya,Kavitha Siva,Julian Pulecio,Carl R Walkley,Vijay G Sankaran,Violeta Rayon-Estrada

doi:10.1016/j.celrep.2016.05.027

Abstract

SummaryErythroid cell commitment and differentiation proceed through activation of a lineage-restricted transcriptional network orchestrated by a group of well characterized genes. However, the minimal set of factors necessary for instructing red blood cell (RBC) development remains undefined. We employed a screen for transcription factors allowing direct lineage reprograming from fibroblasts to induced erythroid progenitors/precursors (iEPs). We show that Gata1, Tal1, Lmo2, and c-Myc (GTLM) can rapidly convert murine and human fibroblasts directly to iEPs. The transcriptional signature of murine iEPs resembled mainly that of primitive erythroid progenitors in the yolk sac, whereas addition of Klf1 or Myb to the GTLM cocktail resulted in iEPs with a more adult-type globin expression pattern. Our results demonstrate that direct lineage conversion is a suitable platform for defining and studying the core factors inducing the different waves of erythroid development.

Highlights

Several factors are known to participate in the conserved genetic program instructing development of committed erythroid progenitors, the minimal combination of factors required for direct induction of erythroid cell fate remains unknown
Adult tail tip fibroblasts (TTFs) were derived from erythroid lineage-tracing mice (Heinrich et al, 2004), which express the yellow fluorescent protein from the Rosa26 locus in all cells that have expressed the erythropoietin receptor (Epor, Cre knocked into one allele of the endogenous Epor locus) transcript at any stage of their development (Figure 1A)
We found that removal of Gata1, Tal1, Lmo2, or c-Myc from the factor cocktail completely abrogated induced erythroid progenitors/precursors (iEPs) formation (Figure 1C; Figure S1)

Summary

Introduction

Several factors are known to participate in the conserved genetic program instructing development of committed erythroid progenitors, the minimal combination of factors required for direct induction of erythroid cell fate remains unknown. Numerous studies have demonstrated that it is possible to directly convert a mature cell type into another, bypassing the pluripotent state, using a defined set of lineageinstructive transcription factors (Jopling et al, 2011; Takahashi, 2012). This approach, called direct lineage reprogramming, can yield a wide range of clinically relevant cell types, such as neurons, cardiomyocytes, and hepatocytes (Huang et al, 2011; Ieda et al, 2010; Sekiya and Suzuki, 2011; Vierbuchen et al, 2010). We reasoned that direct lineage reprogramming is an unambiguous method for defining the core transcriptional machinery directing RBC development

Results

Discussion

Conclusion