RNA-seq of human iPS derived macrophages with or without KLF1- transcription factor Activation

Red blood cells (RBCs) mature within a specialized niche (the erythroblastic island (EI)), which consists of a central macrophage surrounded by differentiating erythroblasts. Human Induced Pluripotent Stem Cell derived macrophages (iPSC-DMs) enhance proliferation and terminal maturation of Umbilical Cord Blood (UCB) CD34+ derived erythroid cells and iPSC derived erythroid cells. These effects are further increased when an inducible KLF1-ERT2 fusion protein is activated in iPSC-DMs. To assess the mechanism of action, we sought to compare the transcriptome of iPSC-DMs with and without KLF1 activation. For this, we used an inducible IPSC line (iKLF1.2) in which upon tamoxifen addition, the KLF1 transcription factor is translocated to nucleus and consequently KLF1 downstream targets are expressed. The identification and characterisation of could identify factors involved in erythroid maturation and thus helpful to improve current protocols to manufacture RBCs in vitro. Overall design: iKLF1.2 iPSCs were differentiated to macrophages and then split into 2 groups, one was treated with tamoxifen for the last 4 days of culture to activate KLF1. The other group was not treated with tamoxifen. Four biologically independent differentiation experiments were carried out and so 8 samples were generated: 4 samples of untreated iKLF1.2 iPSCs-derived macrophages and 4 samples of tamoxifen treated iKLF1.2 iPSC-derived macrophages. Total RNA was extracted from each sample and RNA integrity was of a high enough quality for library preparation, as all RIN values were above 9 for every sample.

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Lopez-Yrigoyen M, Yang CT, Fidanza A, Cassetta L, Taylor AH, McCahill A, Sellink E, von Lindern M, van den Akker E, Mountford JC, Pollard JW, Forrester LM