Figure 5.

AML Engraftment Is Associated with Increased Nitric Oxide Levels in the BM

(A) Nitric oxide levels shown as DAF fluorescence intensity (normalized mean fluorescence intensity [MFI]) in BM cells of non-transplanted mice (ctrl) and mice transplanted with CB-derived HSPCs (CB) or AML patient-derived samples, as depicted. Ctrl, n = 13; CB, n = 24; AML patients (AML1, 2, 6, 8, 9), n = 35. Data are shown as minimum-to-maximum box plots, the line inside the box representing the mean.

(B) Nitric oxide levels (normalized MFI) in BM cells of mice transplanted with AML patient-derived cells, treated with solvent or AraC, as depicted. AML patients: AML6 and 9. UT, n = 7; AraC, n = 7. Data are shown as minimum-to-maximum box plots, the line inside the box representing the mean.

(C) Nitric oxide levels in BM cells of healthy donors or AML patients at diagnosis. Healthy ctrl, n = 8; AML patients, n = 19. Error bars represent mean ± SEM.

(D) Nitric oxide levels in BM cells of AML patients at diagnosis (D) and post treatment (PT); n = 18. Error bars represent mean.

(E) Pie chart showing the percentage of patients with decreased or stable/increased levels of nitric oxide after treatment.

(F) NOS3 expression measured via flow cytometry in Nestin⁺ and CD31⁺ cells, as depicted. Data are representative of triplicates.

(G) Percentage of NOS3⁺ ECs measured by flow cytometry in the BM of non-transplanted mice and mice engrafted with CB-derived HSPCs (CB) or AML patient-derived samples, as depicted. Ctrl, n = 8; CB, n = 12; AML patients (AML2, 6, 8, 9), n = 24. Data are shown as mean ± SEM.

(H) Activated NOS3 (measured by flow cytometry with an anti-phosphoSer1177 antibody) in CD31⁺ ECs of the BM of mice engrafted with CB-derived CD34⁺ cells (CB) or AML patient-derived samples, as depicted. CB, n = 4; AML patients (AML2, 6, 9), n = 9. Data are shown as mean ± SEM.

(I) Cellular ROS (left) and nitric oxide (right) levels in different populations of BM-derived ECs, as depicted, in non-transplanted mice (ctrl). Data are representative of triplicates.

(J) Cellular ROS (left) and nitric oxide (right) levels in different populations of BM-derived ECs, as depicted, in mice engrafted with AML6 patient-derived cells. Data are representative of triplicates.

ns, not significant; ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗∗p < 0.0001. See also Figure S5.