CD11b⁺ interstitial macrophages are required for ischemia-induced lung angiogenesis

Abstract

The importance of myeloid cells in promoting neovascularization has been shown in a number of pathological settings in several organs. However, the specific role of macrophages in promoting systemic angiogenesis during pulmonary ischemia is not fully determined. Our past work suggested that cells of monocytic lineage contributed to systemic angiogenesis in the lung since clodronate‐induced depletion of all macrophages resulted in attenuated neovascularization. Our current goals were to define the population of macrophages important for systemic vessel growth into the lung after the onset of pulmonary ischemia in mice. Interstitial macrophages (CD64+ MerTK + CD11b+) increased significantly as did the percent of CD45+ Ly6G+ neutrophils 1 day after the induction of left lung ischemia, despite the fact there was limited cell recruitment due to complete obstruction of the left pulmonary artery in this ischemia model. Since both interstitial macrophages and neutrophils express CD11b, we used CD11b+ DTR mice and showed the critical role for these cells since CD11b+ depleted mice showed no systemic angiogenesis 7 days after the onset of ischemia when compared to control mice. Coculture of mouse aortic endothelial cells with macrophages showed increased proliferation relative to endothelial cells in culture without inflammatory cells, or pulmonary artery endothelial cells. We conclude that CD11b+ leukocytes, trapped within the lung at the onset of ischemia, contribute to growth factor release, and are critical for new blood vessel proliferation.

CP‐25 exerts therapeutic effects in mice with dextran sodium sulfate‐induced colitis by inhibiting GRK2 translocation to downregulate the TLR4‐NF‐κB‐NLRP3 inflammasome signaling pathway in macrophages

“…CD45 + cells are surface markers of total leukocytes, and CD11b + F4/80 + cells are markers of total macrophages 37,38 . Compared with the normal group, the percentage of M1 macrophages (CD45 + F4/80 + CD11b + CD86 + ) was significantly elevated, and the percentage of M2 macrophages (CD45 + F4/80 + CD11b + CD206 + ) was dramatically reduced in the DSS model group.…”

“…and the TLR4-NF-κB-NLRP3 inflammasome signaling pathway in mice with DSS-induced colitis CD45 + cells are surface markers of total leukocytes, and CD11b + F4/80 + cells are markers of total macrophages. 37,38 Compared with the normal group, the percentage of M1 macrophages (CD45 + F4/80 + CD11b + CD86 + ) was significantly elevated, and the percentage of M2 macrophages (CD45 + F4/80 + CD11b + CD206 + ) was dramatically reduced in the DSS model group. CP-25 reduced the elevated percentage of CD45 + F4/80 + CD11b + CD86 + macrophages and increased the percentage of the CD45 + F4/80 + CD11b + CD206 + macrophages (n = 5, 0.29 ± 0.04 vs. 1.48 ± 0.03, p < .01; Figure 2i,j).…”

Hydrogen Attenuates Endotoxin-Induced Lung Injury by Activating Thioredoxin 1 and Decreasing Tissue Factor Expression

“…PBS was used to wash the sample again, then the mixture was resuspended in 1 ml of 0.01 M PBS and subjected to flow cytometry analysis (FACS Verse; BD, New Jersey, Franklin Lakes, USA). The cells positive for all three antibodies were considered to be neutrophils (29)(30)(31). Waltham, MA, city, state, USA) was set to 5% CO 2 , 37 • C, and a controlled humidity.…”