Advertisement

Aid is a key regulator of myeloid/erythroid differentiation and DNA methylation in hematopoietic stem/progenitor cells

Hiroyoshi Kunimoto, Anna Sophia McKenney, Cem Meydan, Kaitlyn Shank, Abbas Nazir, Franck Rapaport, Benjamin Durham, Francine E. Garrett-Bakelman, Elodie Pronier, Alan H. Shih, Ari Melnick, Jayanta Chaudhuri and Ross L. Levine

Key points

  • Loss of Aid leads to altered myeloid/erythroid differentiation, transcription and methylation in specific genetic loci in HSPCs.

  • Aid loss does not contribute to enhanced HSC self-renewal or cooperate with Flt3-ITD in myeloid leukemogenesis.

Abstract

Recent studies have reported activation-induced cytidine deaminase (AID) and ten-eleven-translocation (TET) family members regulate active DNA demethylation. Genetic alterations of TET2 occur in myeloid malignancies and hematopoietic specific loss of Tet2 induces aberrant hematopoietic stem cell (HSC) self-renewal/differentiation, implicating TET2 as a master regulator of normal and malignant hematopoiesis. Despite the functional link between AID and TET in epigenetic gene regulation, the role of AID loss in hematopoiesis and myeloid transformation remains to be investigated. Here, we show that Aid loss in mice leads to expansion of myeloid cells and reduced erythroid progenitors resulting in anemia, with dysregulated expression of Cebpa and Gata1, myeloid/erythroid lineage specific transcription factors. Consistent with data in the murine context, silencing of AID in human bone marrow (BM) cells skews differentiation towards myelomonocytic lineage. However, in contrast to Tet2 loss, Aid loss does not contribute to enhanced HSC self-renewal or cooperate with Flt3-ITD to induce myeloid transformation. Genome-wide transcription and differential methylation analysis uncover the critical role of Aid as a key epigenetic regulator. These results indicate that AID and TET2 share common effects on myeloid and erythroid lineage differentiation, however their role is non-redundant in regulating HSC self-renewal and in myeloid transformation.

  • Submitted June 10, 2016.
  • Accepted January 7, 2017.