Bone marrow cells recruited through the neuropilin-1 receptor promote arterial formation at the sites of adult neoangiogenesis in mice
J. Clin. Invest. Serena Zacchigna, et al. 118:2062 doi:10.1172/JCI32832 [Go to this article.]

Figure 5
Soluble factors produced by CD11b⁺ cells stimulate SMC migration and proliferation. (A) CD11b⁺ and CD11b^– cells were used as chemoattractants for primary coronary artery SMCs. Histograms show the mean number of migrated cells ± SD, as counted in more than 8 fields per membrane. Regression analysis indicated that the only supernatant conditioned by CD11b⁺ cells was able to recruit SMC cells in a dose-related manner (r = 0.71; P < 0.05). (B) SMCs and HUVECS were exposed to medium conditioned by CD11b⁺ cells, and cell proliferation was measured by MTT assay. SMCs but not HUVECs responded to mitogens secreted by CD11b⁺ cells. Shown are means ± SD of 3 experiments. *P < 0.05 over unstimulated cells; F = 245.0 and 0.32 for SMCs and HUVECs, respectively. (C) SMCs and HUVECs were exposed to a medium conditioned by CD11b⁺ cells previously primed by 50 ng/ml of hrVEGF₁₂₁ or hrVEGF₁₆₅. Upon exposure to both VEGF isoforms, CD11b⁺ cells became able to stimulate the proliferation of both SMCs (as in B) and HUVECs. Shown are means ± SD of 3 experiments. *P < 0.05 over unstimulated cells; F = 90.61 and 143.6 for SMCs and HUVECs, respectively. (D) The expression levels of a panel of candidate genes were determined by real-time PCR in muscles injected with AAV-VEGF₁₂₁ or AAV-VEGF₁₆₅. Data are presented as a ratio between the VEGF-expressing and the mock-injected contralateral muscles. Shown are means ± SD. n ≥ 6. (E) The same transcripts considered in part D were also analyzed in primary CD11b⁺ BM cells. Shown are means ± SD of 3 independent quantifications.