Mitigating oxygen stress enhances aged mouse hematopoietic stem cell numbers and function
Maegan L. Capitano, … , Christie M. Orschell, Hal E. Broxmeyer
Maegan L. Capitano, … , Christie M. Orschell, Hal E. Broxmeyer
Published January 4, 2021
Citation Information: J Clin Invest. 2021;131(1):e140177. https://doi.org/10.1172/JCI140177.
View: Text | PDF
Research Article Aging Hematology

Mitigating oxygen stress enhances aged mouse hematopoietic stem cell numbers and function

Abstract

Bone marrow (BM) hematopoietic stem cells (HSCs) become dysfunctional during aging (i.e., they are increased in number but have an overall reduction in long-term repopulation potential and increased myeloid differentiation) compared with young HSCs, suggesting limited use of old donor BM cells for hematopoietic cell transplantation (HCT). BM cells reside in an in vivo hypoxic environment yet are evaluated after collection and processing in ambient air. We detected an increase in the number of both young and aged mouse BM HSCs collected and processed in 3% O2 compared with the number of young BM HSCs collected and processed in ambient air (~21% O2). Aged BM collected and processed under hypoxic conditions demonstrated enhanced engraftment capability during competitive transplantation analysis and contained more functional HSCs as determined by limiting dilution analysis. Importantly, the myeloid-to-lymphoid differentiation ratio of aged BM collected in 3% O2 was similar to that detected in young BM collected in ambient air or hypoxic conditions, consistent with the increased number of common lymphoid progenitors following collection under hypoxia. Enhanced functional activity and differentiation of old BM collected and processed in hypoxia correlated with reduced “stress” associated with ambient air BM collection and suggests that aged BM may be better and more efficiently used for HCT if collected and processed under hypoxia so that it is never exposed to ambient air O2.

Authors

Maegan L. Capitano, Safa F. Mohamad, Scott Cooper, Bin Guo, Xinxin Huang, Andrea M. Gunawan, Carol Sampson, James Ropa, Edward F. Srour, Christie M. Orschell, Hal E. Broxmeyer

×

Figure 2

HSC engraftment efficiency of young and old C57BL/6 mice collected/processed under ambient air versus hypoxia as assessed by BM transplantation and limiting dilution analysis.

Options: View larger image (or click on image) Download as PowerPoint
HSC engraftment efficiency of young and old C57BL/6 mice collected/proce...
(A) Schematic of the experiment. Donor BM cells collected in ambient air versus hypoxia and competitor cells collected in 21% O2 were injected i.v. in either 3% O2 (hypoxia) or 21% O2 (ambient air) into 950 cGy–irradiated CD45.1+CD45.2+ F1 recipients (25,000, 50,000, and 100,000 donor cells, with 150,000 competitor cells). The percentages of donor cells (CD45.1–CD45.2+) in PB (B) and BM (C) were determined from the 50,000-cell-dose group. Data represent the mean ± SEM for 4–6 recipient mice. (D–G) Secondary transplantations of primary recipient BM collected under ambient air conditions. The percentages of donor cells in PB (D–F) and BM (G) were determined. Data represent the mean ± SEM of 8 mice per group. (H) Left: Poisson statistical analysis from limiting dilution transplantation. Shapes represent the percentages of negative mice for each cell dose, solid lines indicate the best-fit linear model, and dotted lines represent 95% CIs. Right: Number of CRU in 1 × 106 BM cells. Data represent the mean ± SEM for 4–6 F1 recipient mice. (See Supplemental Table 1 for more details.) *P < 0.05, **P < 0.01, and ***P < 0.001, by 1-way ANOVA with post hoc Tukey’s multiple-comparison test (B–G). 1°, primary; 2°, secondary.