NOTCH-mediated ex vivo expansion of human hematopoietic stem and progenitor cells by culture under hypoxia

• Published in: Stem cell reports Vol. 16; no. 9; pp. 2336 - 2350
• Main Authors: Araki, Daisuke, Fu, Jian Fei, Huntsman, Heather, Cordes, Stefan, Seifuddin, Fayaz, Alvarado, Luigi J., Cheruku, Patali S., Cash, Ayla, Traba, Javier, Li, Yuesheng, Pirooznia, Mehdi, Smith, Richard H., Larochelle, Andre
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 14.09.2021; Elsevier
• Subjects: Antigens, CD34 - metabolism; Biomarkers; Cell Culture Techniques; Cell Differentiation; Cell Hypoxia; Cell Proliferation; Computational Biology - methods; endoplasmic reticulum stress; expansion; gene therapy; hematopoietic stem cell; Hematopoietic Stem Cells - cytology; Hematopoietic Stem Cells - metabolism; Humans; hypoxia; Molecular Sequence Annotation; Notch; pathways; Receptors, Notch - genetics; Receptors, Notch - metabolism; Signal Transduction; signaling; Transcriptome; transplantation; hypoxia; signaling; Notch; transplantation; hematopoietic stem cell; gene therapy; pathways; endoplasmic reticulum stress; expansion
• ISSN: 2213-6711; 2213-6711
• DOI: 10.1016/j.stemcr.2021.08.001

Activation of NOTCH signaling in human hematopoietic stem/progenitor cells (HSPCs) by treatment with an engineered Delta-like ligand (DELTA1ext-IgG [DXI]) has enabled ex vivo expansion of short-term HSPCs, but the effect on long-term repopulating hematopoietic stem cells (LTR-HSCs) remains uncertain. Here, we demonstrate that ex vivo culture of human adult HSPCs with DXI under low oxygen tension limits ER stress in LTR-HSCs and lineage-committed progenitors compared with normoxic cultures. A distinct HSC gene signature was upregulated in cells cultured with DXI in hypoxia and, after 21 days of culture, the frequency of LTR-HSCs increased 4.9-fold relative to uncultured cells and 4.2-fold compared with the normoxia + DXI group. NOTCH and hypoxia pathways intersected to maintain undifferentiated phenotypes in cultured HSPCs. Our work underscores the importance of mitigating ER stress perturbations to preserve functional LTR-HSCs in extended cultures and offers a clinically feasible platform for the expansion of human HSPCs. [Display omitted] •Superior NOTCH-mediated expansion of human HSPCs in hypoxic cultures•Culture under hypoxia mitigates ER stress in human HSPCs•Hypoxia potentiates NOTCH intracellular signaling in cultured human HSPCs Larochelle and colleagues concurrently activate NOTCH and hypoxic pathways in ex vivo cultures of human adult HSPCs to enable a clinically relevant expansion of cells with long-term repopulating potential after transplantation. They characterize the molecular intersection between the two signaling pathways and demonstrate the important role of low oxygen tension in mitigating ER stress during NOTCH-mediated expansion of human HSPCs.