Figure 4. HO‐1 deficiency causes loss of LT‐HSC quiescence and expansion of stem cell pool.

• A
  Gating strategy of hematopoietic stem and progenitor cells.
• B–D
  Young HO‐1^−/− mice possess higher number of (B) LT‐HSCs, (C) ST‐HSCs, and (D) MPPs.
• E
  Exemplary analysis of cell cycle with Ki67 and nuclear dye.
• F
  More young HO‐1^−/− LT‐HSCs are in G1 and S/G2/M cell cycle phases. The presented cell cycle analysis is from two independent experiments.
• G
  Young HO‐1^−/− MPPs do not differ in cell cycling from young HO‐1^+/+ MPPs. The presented cell cycle analysis is from two independent experiments.
• H
  More old HO‐1^−/− LT‐HSCs are in G1 phase in comparison with old HO‐1^+/+ LT‐HSCs, but not in S/G2/M phase. The presented cell cycle analysis is from two independent experiments.
• I
  Old MPPs do not differ in cell cycling between genotypes. The presented cell cycle analysis is from two independent experiments.
• J
  Young HO‐1^−/− LT‐HSCs contain more γH2aX^high cells than young HO‐1^+/+; 378–991 cells analyzed from seven mice/group.
• K
  Young HO‐1^−/− MPPs contain more γH2aX^high cells than young HO‐1^+/+; 1,693–2,790 cells analyzed from seven mice/group.
• L, M
  Alkaline comet assay revealed that HO‐1^−/− LT‐HSCs possess (L) higher oil tail moment and (M) more DNA in the comet tail. 1,068–1,189 cells analyzed from six mice/group.
• N
  HSCs from young HO‐1^−/− mice provide worse hematopoietic reconstitution after transplantation than HO‐1^+/+ HSCs. Data are shown as mean ± SEM, n = 8–9 mice/group.

Data information: For comparison of two groups unpaired, two‐tailed t‐test was used. For contingency analysis (J and K), Fisher's exact test was applied. For two variable comparisons (N), 2‐way ANOVA with Bonferroni post‐test was used. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.