Figure 1

miR-34a is involved in transient BBB opening following murine experimental stroke. (A) Flow cytometry data showed purity of magnetically isolated pCECs used to collect the data in (B), which showed a significant increase in miR-34a at 6 h post-stroke and no significant change at 24 h post-stroke following 1 h tMCAO. Expression of miR-34a was normalized to internal control miR-39. The data are normalized to naive controls. N = 10 per time point, ***p < 0.001, and one-way ANOVA followed by post hoc Tukey’s test was used for data analysis. Data are expressed as mean ± S.D. (C) The middle cerebral artery was occluded for 1 h in miR34a^−/− mice and WT controls. Evan’s blue administered intravenously at 6 h post-stroke. Transcardial perfusion was performed, and brain images were photographed as shown by the representative coronal brain sections. Red arrows indicate Evan’s blue extravasation. (D) Quantified Evan’s blue extravasation in the left and right hemispheres showed miR-34a depletion decreased BBB permeability, as quantified by µg/g brain tissue in each hemisphere. **p < 0.01, n = 12 per group, and one-way ANOVA followed by post hoc Tukey’s test was used for data analysis. Representative coronal brain images showing BBB opening detected by rhodamine-123 infiltration) (E) and Texas Red infiltration (G) ischemic brains from WT and miR-34a^−/− mice following 1 h tMCAO and 6 h reperfusion. White arrows indicate fluorescent dye infiltration. Quantification of green fluorescence intensity for rhodamine-123 infiltration (F) and red fluorescence intensity for Texas Red infiltration (H). *p < 0.05, n = 5 per group, and one-way ANOVA followed by post hoc Tukey’s test was used for data analyses.