Figure 4. Transplanting BMMSCs-shRac1 promotes the recovery of neurological functions and reduces brain edema after TBI. (A) Images displaying the whole brain and ipsilateral TBI brain stained with H&E 7 days and 21 days after BMMSCs (parental BMMSCs, BMMSCs-shLuci, BMMSCs-shRac1) transplantation or after PBS injection. The scale bar of 1 mm and 2 mm is indicated, respectively. (B) Quantification of lesional volume in the BMMSCs-transplanted versus placebo (PBS) mice. The lesional size was smallest in BMMSCs-shRac1 transplanted mice at 7 days post transplantation (DPT) and 21 DPT. (N.S. no significance, *P < 0.05, **P < 0.01, ***P < 0.001, statistically analyzed by one-way ANOVA followed by the Bonferroni correction, n = 5). (C) Quantitative analysis of brain moisture content in each group. Mice treated with parental BMMSCs, BMMSCs-shLuci, and BMMSCs-shRac1 had less edema compared with PBS injection group at 7 DPT, with the BMMSCs-shRac1 group showing minimal edema. No significance was found at 21 DPT. (N.S. no significance, #P < 0.05, *P < 0.05, ***P < 0.001, statistically analyzed by one-way ANOVA followed by the Bonferroni correction, n = 6). (D) mNSS scores for mice treated with PBS, parental BMMSCs, BMMSCs-shLuci, or BMMSCs-shRac1, with the latter achieving the lowest score. (**P < 0.01, ***P < 0.001, statistically analyzed by two-way ANOVA followed by the Bonferroni correction, n = 8). (E) Rotarod test of mice treated with PBS, parental BMMSCs, BMMSCs-shLuci, or BMMSCs-shRac1, where the latter achieved the maximum stay-on time at each time point after transplantation (**P < 0.01, statistically analyzed by two-way ANOVA followed by Bonferroni correction, n = 8). Data are presented as mean ± SD.