Fig. 1

AZM treatment increases alternative macrophage activation in mouse SCI. Animals were subjected to a moderate-severe T9 SCI and treated with 160 mg/kg AZM or vehicle using a combined pre- (3 days) and post- (up to 7 days) SCI daily treatment regimen. a, b Scatter plots of CD11b/CD45+ cells isolated from spinal cord homogenates after sham or contusion SCI. Cells were collected from 10 mm of spinal cord tissue centered on the lesion epicenter. The specificity of the gates is evident as neutrophils and monocytes enter the spinal cord only after SCI (b). c Quantification of neutrophils (CD11b⁺/CD45^hi/GR1^hi), monocyte-derived macrophages (CD11b⁺/CD45^hi/GR1^lo/neg), and microglia (CD11b⁺/CD45^lo/GR1^lo/neg) (gates indicated in b) following vehicle or AZM treatment (1 dpi sham values indicated with dotted line). AZM significantly attenuated monocyte recruitment to the spinal cord at 3 dpi (p = 0.03). d rtPCR of mRNA expression in FACS-sorted macrophages (combined monocyte and microglia populations identified in b) reveal significant increases in gene expression for the M2 markers arginase 1 and CD206 in AZM vs. vehicle controls (values relative to sham expression levels indicated with dotted line). The M1 marker, CD86, was significantly decreased with AZM treatment. e Representative plots for microglia-derived macrophages (CD11b⁺/CD45^lo/GR1^lo/neg) showing labeling with CD206 primary antibody and unstained controls. There is a significant increase in the number of CD206+ microglia-derived macrophages with AZM treatment. ⁺ p < 0.06, *p < 0.05, **p < 0.01, ***p < 0.001; n = 3–5