Figure 4

Metformin promoted ZO-1, occludin and claudin-5 rearrangement and lessened IgG and Evans blue extravasation. (A) Occludin, ZO-1 and claudin-5 expression in sham group, NS and metformin-treated mice at 3 days following tMCAO. Scale bar =10 μm. (B) Representative result of occludin, ZO-1 and claudin-5 expression at 1 and 3 days after tMCAO. Bar graphs show a quantification of occludin, ZO-1 and claudin-5 expression. (C) IgG leakage at 3 days following tMCAO in saline and metformin-treated group. Higher magnifications are shown below. Boxes displayed representative IgG staining. Scale bar =1 mm (upper) and 100 μm (lower). Bar graph shows a semi-quantification of integrated optical density (IOD) of IgG at 1 and 3 days after tMCAO (n =3 per group). (D) Images show Evans blue extravasation in sham (a), saline (b) and metformin (c) group at 3 days after tMCAO. Blue area indicates extravasation of Evans blue. Bar graph shows a quantification analysis of Evans blue contents in brain tissue (n =3 per group). Data were mean ± SD, *P < 0.05, metformin versus saline group, **P < 0.01, metformin versus saline group.