Figure 8. Blocking TMEM16A partially restores capillary perfusion after CCAO.

(A) Isolectin B4–labeled cortical capillaries in fixed slices (purple); FITC-albumin in gelatin (recolored red) shows perfused vessels 1.5 hours after sham operation or CCAO without or with Ani9 (10 μM). Yellow arrows indicate pericyte somata less than 5 μm from capillary blocks. Right images show 3D tracing of FITC-albumin in perfused (white) or unperfused (magenta) capillaries. Scale bar: 20 μm. (B) Cumulative probability distribution of distance of 110 pericyte somata to capillary occlusions (black). The red line denotes the predicted distribution assuming pericytes are uniformly spaced along the capillary (see Supplemental Figure 5E) and blocks occur randomly (2-sample Kolmogorov-Smirnov test). (C) Extent of perfusion of 3D-traced capillaries. Points indicate individual confocal stacks from P30–P72 CCAO (aCSF) (n = 25), P31–P83 CCAO Ani9 (n = 16), and P39–P62 sham aCSF (n = 9) mice (Kruskal-Wallis test with Dunn’s post hoc test). (D) Ly6G-labeled neutrophil in a third order capillary in a fixed cortical slice at 1.5 hours after CCAO. The neutrophil obstructs blood flow (revealed by FITC-gelatin staining). Zoomed-in image of the right end of the block and left end of neutrophil (“Block start”) shows a possible red blood cell (RBC) to the left of the neutrophil. Scale bar: 10 μm. (E) Distribution of 109 neutrophils versus distance from the nearest pericyte soma. (F) Neutrophils in cerebral capillaries per confocal stack at 1.5 hours after CCAO in the absence (n = 18) or presence (n = 33) of Ani9 (10 μM) (Mann-Whitney test). (G) CD41-labeled platelets (or aggregates thereof) in third and fourth order capillary branches in a fixed cortical slice at 1.5 hours after CCAO. (H) Platelets (or platelet aggregates) in cerebral capillaries per confocal stack at 1.5 hours after CCAO in the absence (n = 71) or presence (n = 60) of Ani9 (10 μM) (Mann-Whitney test). The numbers of animals are specified in Supplemental Table 2.