Fig. 1

LPS and IL-4 promoted angiogenesis and macrophage polarization in a mouse HLI model. After left artery ligation, the mice received PBS, LPS and IL-4 intramuscular injection on day 0, 3 and 7 post-surgery (n = 10). A–C, Laser speckle data showing the relative level of blood perfusion in the hind paws on the indicated days (scale bar: 1000 µm, A and B). Quantitative analyses of the laser speckle images showing the left/right ratio of plantar blood perfusion (D7 and D21, C). D The percentages of dead cells in gastrocnemius muscles from ligated hindlimb on D3, D7, D14, and D21 post-surgery (Tunel Assay, scale bar: 100 µm). E Macrophage were isolated from adductor muscles and the surface markers, CD86 (pro-inflammatory polarization marker), and CD206 (anti-inflammatory polarization marker) were checked using flow cytometry. Total 5000 cells were gated and analyzed. F The phagocytosis of pHrodo Red-labeled hypoxia or nutrition deprivation induced apoptotic mCMVEC by the macrophages isolated from adductor muscles of the mice that received various treatment. Total 5000 cells were analyzed. G, H The cytokines (F) and growth factors (G) secreted from the macrophages that were collected from adductor muscles of mice 14 days post-surgery, were measured using ELISA. I, J The secreted cytokines (H) and growth factors (I) from the were collected from adductor muscles of mice 21 days post-surgery. K The level of Sirpα in the macrophages collected from adductor muscles of the mice that received various treatment on indicated days post-surgery (n = 3). Data is analyzed using one-way ANOVA followed by Tukey multiple range test and expressed as mean ± SD of n = 5, unless specified. *p < 0.05, **p < 0.01, ***p < 0.001 and ****p < 0.0001. ns, non-significant