Fig. 5

Signature polarization genes are upregulated in brain macrophages post-TBI. a RNA flow cytometry was performed on bone marrow-derived macrophages (BMDM) that were gated for surface Itgam (CD11b) expression and intracellular Actb RNA expression. The latter is a gate for permeabilized cells. b RNA flow cytometry was performed on unstimulated (gray), LPS-polarized (red), and IL4-polarized (blue) BMDM. Probes for RNA expression of M(LPS, IFNγ) markers, Tnf and Il1b, and M(IL4) markers, Arg1 and Mrc1 were used to stain permeabilized BMDM and analyzed by flow cytometry. N = 3 independent experiments. c Ipsilateral hemisphere brain leukocytes were harvested from mice 1 day after TBI or sham surgery. Flow cytometry plots represent the gates used for live macrophages. d Macrophages harvested from ipsilateral brain hemispheres of mice 1 day after TBI (left, n = 6 independent experiments) and sham surgery (right, n = 3 independent experiments) were assessed by RNA flow cytometry. Analysis markers were drawn based on non-specific background staining using DapB RNA probes for a bacterial gene. The percentage of positive expression shown is the difference in the percent of brain macrophages expressing the M1 or M2 gene and the percent of cells with background detection of DapB RNA