Background:

StemRegenin 1 (SR1), a purine derivative, is a potent small molecule inhibitor of aryl hydrocarbon receptor (AhR) that potently antagonizes AhR with a value of 50% inhibition concentration IC₅₀of 127 nM in CD34⁺cells. SR1 has been found to promote the ex vivo expansion of CD34⁺cells. Recent study results have suggested that culture of hematopoietic stem cells (HSC) with SR1 increases cells expressing CD34 by fifty-fold and increases cells retaining the ability to engraft immunodeficient mice by 17-fold. SR1 has also been found to induce the ex vivo differentiation of pDCs, BDCA1⁺and BDCA3⁺mDCs as well as the generation of high numbers of all these DC subsets.

Reference

[1].Thordardottir S, Hangalapura BN, Hutten T, Cossu M, Spanholtz J, Schaap N, Radstake TR, Vandervoort R, Dolstra H. The aryl hydrocarbon receptor antagonist StemRegenin 1 promotes human plasmacytoid and myeloid dendritic cell development from CD34+ hematopoietic progenitor cells. Stem Cells Dev. 2013 Dec 10. [Epub ahead of print]
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