Fig. 2

High expression of FOXO1 in neutrophils aggravates neuronal damage in the acute stage of TBI. a Mortality of mice within 48 h after from TBI (n = 50). b Behavioural recovery of mice was assessed using the Longa score and mNSS at 48 h post-TBI (sham group, n = 6; WT TBI mice, n = 7; FOXO1^△Lyz2 TBI mice, n = 8). c Immunostaining of the neutrophil marker CD177 (green), FOXO1 (red), and nuclei (DAPI, blue) in brain tissue from 3 TBI patients. Scale bar = 5 μm. d Immunostaining of the neutrophil markers LY6G (green), FOXO1 (red), and nuclei (DAPI, blue) in brain tissue from the TBI mouse model (n = 5). Scale bar = 10 μm. e Flow cytometry analysis of the percentage of FOXO1^high neutrophils among leukocytes in peripheral blood of sham group and TBI mice. The experiment was repeated three times and n = 8 mice per group each time. f Western blotting showing the expression of NeuN in brain injury areas of mice. g Immunostaining of the neuron marker NeuN (red) and nuclei (DAPI, blue) in brain tissue from mice. Scale bar = 50 μm. In f and g, n = 6 per group for assay while here showed 3 biologically independent samples to represent the average status. Data are represented as the mean ± SEM. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001, ns non-significant. FOXO1 forkhead box protein O1, TBI traumatic brain injury, WT wild-type, mNSS modified neurological severity score, DAPI 4,6-diamidino-2-phenylindole dihydrochloride, NeuN neuronal nuclear antigen