Fig. 6: SEMA3A promotes BM EC apoptosis via activation of Cdk5 and p53.
From: Neuropilin 1 regulates bone marrow vascular regeneration and hematopoietic reconstitution
a (Left) flow cytometry of activated caspase 3/7+ BM ECs in wild-type (WT) and Nrp1VEGF− mice at day +5 following 500 cGy and the treatments shown; (Right) % activated caspase 3/7+ BM ECs (n = 5/group; ****p < 0.0001; ***p = 0.0003). b (Left) Donor CD45.2+ cell engraftment at 20 weeks in the PB of CD45.1+ mice competitively transplanted with BM cells from 500 cGy—irradiated Nrp1VEGF− mice treated with anti-NRP1 or IgG; (Right) % donor CD45.2+, Mac1+/Gr1+, B220+, and CD3+ cells at 20 weeks (n = 5–6/group; total: p = 0.0346; myeloid: p = 0.0325; T cells: p = 0.0195). c (Left) Histograms of p-Cdk5+ BM ECs at 1 h following 800 cGy and the treatments shown; (Right) %p-p53+ BM ECs. Horizontal lines show gating for p-Cdk5+ cells (n = 5 replicates, Non-IRR; n = 6 replicates for IRR, IRR + SEMA3A, IRR + SEMA3A + anti-NRP1; non-IRR vs. IRR: p < 0.0001; IRR vs. IRR + SEMA3A: p = 0.0005; IRR vs. IRR + SEMA3A + Anti-NRP1 p < 0.0001). d % activated caspase 3/7+ BM ECs at 24 h following 800 cGy and treatment with SEMA3A, SEMA3A + anti-NRP1 or SEMA3A + roscovitine (ROSC), 10 ng/ml (n = 4–8 replicates; non-IRR vs. IRR: p < 0.0001; IRR vs. IRR + SEMA3A: p = 0.0007; IRR vs. IRR + SEMA3A + Anti-NRP1 p < 0.0001; IRR vs. IRR + SEMA3A + Anti-NRP1 + ROSC p < 0.0001). e At left, histograms of p-p53+ BM ECs at 1 h following 800 cGy and treatment with SEMA3A, SEMA3A + anti-NRP1, or SEMA3A + ROSC. At right, % p-p53+ BM ECs are shown. Black horizontal lines show gating for p-p53+ cells (n = 6 replicates, Non-IRR; n = 9 replicates for IRR and IRR + SEMA3A; n = 5 replicates for IRR + SEMA3A + anti-NRP1; n = 4 replicates for IRR + SEMA3A + ROSC; p < 0.0001 for all comparisons). f At left, flow cytometry for activated caspase 3/7+ BM ECs from p53−/− and p53+/+ mice at 24 h following irradiation with 800 cGy and the treatments shown. At right, % activated caspase 3/7+ BM ECs are shown (n = 5 replicates/group, p < 0.0001). g Puma expression in BM ECs at 6 h following 800 cGy and the treatments shown (n = 4/condition; ****p < 0.0001, *p = 0.0142, **p = 0.0025, ***p = 0.0009). a, c, d, e One-way ANOVA followed by Holm-Sidak’s two-sided unpaired t-tests, f Two-way ANOVA followed by Holm-Sidak’s two-sided unpaired t-test, g Brown–Forsythe ANOVA followed by two-sided unpaired t-tests with Welch’s correction, b Two-sided Mann–Whitney test. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. Source Data file provided.
