Zeb1 modulates hematopoietic stem cell fates required for suppressing acute myeloid leukemia
Alhomidi Almotiri, … , Florian A. Siebzehnrubl, Neil P. Rodrigues
Alhomidi Almotiri, … , Florian A. Siebzehnrubl, Neil P. Rodrigues
Published October 27, 2020
Citation Information: J Clin Invest. 2021;131(1):e129115. https://doi.org/10.1172/JCI129115.
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Research Article Hematology

Zeb1 modulates hematopoietic stem cell fates required for suppressing acute myeloid leukemia

Abstract

Zeb1, a zinc finger E-box binding homeobox epithelial-mesenchymal transition (EMT) transcription factor, confers properties of “stemness,” such as self-renewal, in cancer. Yet little is known about the function of Zeb1 in adult stem cells. Here, we used the hematopoietic system as a well-established paradigm of stem cell biology to evaluate Zeb1-mediated regulation of adult stem cells. We employed a conditional genetic approach using the Mx1-Cre system to specifically knock out (KO) Zeb1 in adult hematopoietic stem cells (HSCs) and their downstream progeny. Acute genetic deletion of Zeb1 led to rapid-onset thymic atrophy and apoptosis-driven loss of thymocytes and T cells. A profound cell-autonomous self-renewal defect and multilineage differentiation block were observed in Zeb1-KO HSCs. Loss of Zeb1 in HSCs activated transcriptional programs of deregulated HSC maintenance and multilineage differentiation genes and of cell polarity consisting of cytoskeleton-, lipid metabolism/lipid membrane–, and cell adhesion–related genes. Notably, epithelial cell adhesion molecule (EpCAM) expression was prodigiously upregulated in Zeb1-KO HSCs, which correlated with enhanced cell survival, diminished mitochondrial metabolism, ribosome biogenesis, and differentiation capacity and an activated transcriptomic signature associated with acute myeloid leukemia (AML) signaling. ZEB1 expression was downregulated in AML patients, and Zeb1 KO in the malignant counterparts of HSCs — leukemic stem cells (LSCs) — accelerated MLL-AF9– and Meis1a/Hoxa9-driven AML progression, implicating Zeb1 as a tumor suppressor in AML LSCs. Thus, Zeb1 acts as a transcriptional regulator in hematopoiesis, critically coordinating HSC self-renewal, apoptotic, and multilineage differentiation fates required to suppress leukemic potential in AML.

Authors

Alhomidi Almotiri, Hamed Alzahrani, Juan Bautista Menendez-Gonzalez, Ali Abdelfattah, Badi Alotaibi, Lubaid Saleh, Adelle Greene, Mia Georgiou, Alex Gibbs, Amani Alsayari, Sarab Taha, Leigh-anne Thomas, Dhruv Shah, Sarah Edkins, Peter Giles, Marc P. Stemmler, Simone Brabletz, Thomas Brabletz, Ashleigh S. Boyd, Florian A. Siebzehnrubl, Neil P. Rodrigues

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Figure 3

Loss of Zeb1 results in a reduction of lymphoid progenitors in BM and a multilineage hematopoietic differentiation defect after HSC transplantation.

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Loss of Zeb1 results in a reduction of lymphoid progenitors in BM and a ...
(A) Representative FACS plots of the analysis of LMPP CD127+ (nonconventional LMPP: LSK CD135+CD127+), CLP (LIN– SCA-1loC-KITloCD135+CD127+), and LSK–CD127+CD135+ 14 days after the last dose of pIpC. (B) Frequency of LMPP CD127+, CLP, and LSK–CD 127+CD135+ in the BM from control (n = 8) and Zeb1–/– (n = 10) mice from 4 independent experiments at day 14 after the last pIpC dose. (C) Schematic of competitive HSC transplantation. 150 HSCs from control or Zeb1–/– mice (donor CD45.2) mixed with 2 × 105 BM competitor cells (CD45.1) were transplanted into lethally irradiated recipients (CD45.1), and the mice were monitored by bleeding the tail vein at different time points until week 16. (D) Percentage of donor cells in PB at different time points after HSC transplantation from control (n = 10) and Zeb1–/– (n = 10) mice from 3 independent experiments. Analysis of PB donor contribution to B cells (B220+) (E), MAC1+GR1– myeloid cells (F), MAC1+GR1+ myeloid cells (G), and T cells (CD4+CD8+) (H) from control (n = 10) and Zeb1–/– (n = 8–10) mice from 3 independent experiments. Donor contribution to BM HSPCs (I) (HSC: LSK CD150+CD48–, MPP: LSK CD150–CD48–, HPC1: LSK CD150–CD48+, HPC2: LSK CD150+CD48+) from control (n = 9) and Zeb1–/– (n = 9) from 3 independent experiments and BM committed progenitors (J) (CMP: LK CD34+CD16/32–, GMP: CD34+CD16/32+, MEP: CD34–CD16/32–, CLP: LIN– SCA-1loC-KITloCD127+, and LSK–CD127+ from control (n = 6) and Zeb1–/– (n = 7) from 2 independent experiments. Error bars show mean ± SEM. Mann-Whitney U test was used to calculate significance. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001.