American Society of Hematology

Figure 2.

$Rev1-dependent tolerance of unrepaired endogenous nucleotide lesions protects HSCs (see alsosupplemental Figures 2 and 3). Analysis of the hematopoietic system of WT, ggNER (Xpc), TLS (Rev1), and TLS + ggNER (Rev1Xpc) mice reveals that ggNER and TLS jointly protect HSPCs against cell-autonomous genotoxicity of endogenous helix-distorting DNA lesions. *P < .05; **P < .01; ***P < .001; ****P < .0001. Data are mean ± SEM. (A) Kaplan-Meier curves depicting survival of mice of all 4 genotypes: WT (n = 64), Xpc (n = 10), Rev1 (n = 53), and Rev1Xpc (n = 41). Survival of the different genotypes was compared with WT mice using the Wilcoxon test. (B) Progressive bone marrow aplasia in Rev1Xpc mice. Bar represents 50 μm. Xpc: 1 m (n = 3), 1.5 m (n = 3), 3 m (n = 3), MB (n = 6). Rev1Xpc: 1 m (n = 3), 1.5 m (n = 3), 3 m (n = 3), MB (n = 3). Right panels: Quantification of bone marrow cells at 1 (Xpc, n = 10; Rev1Xpc, n = 11) and 1.5 months (Xpc, n = 4; Rev1Xpc, n = 4) of age, respectively. (C) Rev1Xpc mice develop severe cytopenia. m, months; MB, moribund (see panel A for survival data). WT: 1.5 m (n = 8), 3 m (n = 7), MB (n = 12). Xpc: 1.5 m (n = 5), 3 m (n = 12), MB (n = 7). Rev1: 1.5 m (n = 6), 3 m (n = 17), MB (n = 33). Rev1Xpc: 1.5 m, (n = 10), 3 m (n = 11), MB (n = 10). (D) Relative contribution of myeloid and lymphoid cells in the blood of all genotypes. Note the low contribution of neutrophils specifically in Rev1Xpc blood. (E) Bone marrow aplasia in Rev1Xpc mice is caused by progressive loss of long-term HSCs (LSK-SLAM cells). MNCs, mononuclear cells. Number of mice analyzed: fetal liver: n = 4 for all genotypes. Two-weeks old: Xpc (n = 3), Rev1Xpc (n = 3); 1.5-months old: Xpc (n = 4), Rev1Xpc (n = 4). (F) Increased S/G2/M fractions in Rev1Xpc LSK cells, long-term and short term HSCs from fetal liver, suggesting increased replication, as shown by Ki67 staining (G0 cells are Ki67-negative). N = 4 for all genotypes. (G) Increased proliferation of Rev1Xpc HSPCs as demonstrated by in vivo BrdU labeling. Xpc (n = 3) and Rev1Xpc (n = 3) mice. (H) Rescue of early death, bone marrow aplasia, and cytopenia of Rev1Xpc mice by transplantation with Xpc bone marrow, indicating a hematopoietic cell-intrinsic origin of HSC exhaustion. Survival: Rev1Xpc (n = 41), transplanted Rev1Xpc (n = 10). Bone marrow: Rev1Xpc (n = 3), transplanted Rev1Xpc (n = 5). Blood cellularity: Rev1Xpc (n = 10), transplanted Rev1Xpc (n = 7). Survival of Rev1Xpc mice was compared with WT mice using the Wilcoxon test.$

Rev1-dependent tolerance of unrepaired endogenous nucleotide lesions protects HSCs (see alsosupplemental Figures 2 and 3). Analysis of the hematopoietic system of WT, ggNER (Xpc), TLS (Rev1), and TLS + ggNER (Rev1Xpc) mice reveals that ggNER and TLS jointly protect HSPCs against cell-autonomous genotoxicity of endogenous helix-distorting DNA lesions. *P < .05; **P < .01; ***P < .001; ****P < .0001. Data are mean ± SEM. (A) Kaplan-Meier curves depicting survival of mice of all 4 genotypes: WT (n = 64), Xpc (n = 10), Rev1 (n = 53), and Rev1Xpc (n = 41). Survival of the different genotypes was compared with WT mice using the Wilcoxon test. (B) Progressive bone marrow aplasia in Rev1Xpc mice. Bar represents 50 μm. Xpc: 1 m (n = 3), 1.5 m (n = 3), 3 m (n = 3), MB (n = 6). Rev1Xpc: 1 m (n = 3), 1.5 m (n = 3), 3 m (n = 3), MB (n = 3). Right panels: Quantification of bone marrow cells at 1 (Xpc, n = 10; Rev1Xpc, n = 11) and 1.5 months (Xpc, n = 4; Rev1Xpc, n = 4) of age, respectively. (C) Rev1Xpc mice develop severe cytopenia. m, months; MB, moribund (see panel A for survival data). WT: 1.5 m (n = 8), 3 m (n = 7), MB (n = 12). Xpc: 1.5 m (n = 5), 3 m (n = 12), MB (n = 7). Rev1: 1.5 m (n = 6), 3 m (n = 17), MB (n = 33). Rev1Xpc: 1.5 m, (n = 10), 3 m (n = 11), MB (n = 10). (D) Relative contribution of myeloid and lymphoid cells in the blood of all genotypes. Note the low contribution of neutrophils specifically in Rev1Xpc blood. (E) Bone marrow aplasia in Rev1Xpc mice is caused by progressive loss of long-term HSCs (LSK-SLAM cells). MNCs, mononuclear cells. Number of mice analyzed: fetal liver: n = 4 for all genotypes. Two-weeks old: Xpc (n = 3), Rev1Xpc (n = 3); 1.5-months old: Xpc (n = 4), Rev1Xpc (n = 4). (F) Increased S/G2/M fractions in Rev1Xpc LSK cells, long-term and short term HSCs from fetal liver, suggesting increased replication, as shown by Ki67 staining (G0 cells are Ki67-negative). N = 4 for all genotypes. (G) Increased proliferation of Rev1Xpc HSPCs as demonstrated by in vivo BrdU labeling. Xpc (n = 3) and Rev1Xpc (n = 3) mice. (H) Rescue of early death, bone marrow aplasia, and cytopenia of Rev1Xpc mice by transplantation with Xpc bone marrow, indicating a hematopoietic cell-intrinsic origin of HSC exhaustion. Survival: Rev1Xpc (n = 41), transplanted Rev1Xpc (n = 10). Bone marrow: Rev1Xpc (n = 3), transplanted Rev1Xpc (n = 5). Blood cellularity: Rev1Xpc (n = 10), transplanted Rev1Xpc (n = 7). Survival of Rev1Xpc mice was compared with WT mice using the Wilcoxon test.

This Feature Is Available To Subscribers Only