Figure 3

miR-155 deficiency was associated with preservation of the blood-brain barrier (BBB) in P. berghei ANKA (PbA)-induced ECM. (A) Brains from mice deficient in miR-155 showed improved BBB integrity (less dye leakage into the brain parenchyma). Evans Blue assay was conducted on albino C57BL/6 miR-155^−/− and wild-type miR-155^+/+ littermate controls on d 7 post-PbA infection (1 × 10⁶ parasitized erythrocytes; n = 10–11/group), and representative photographs of brains from mice following Evans Blue dye assay are shown. (B) Brain microvascular leak was reduced in miR-155-deficient mice. Median levels of Evans Blue in the brain was quantified as an indication of vascular leak, and was significantly less in miR-155^−/− than wild-type mice on d 7 post-PbA infection (1 × 10⁶ parasitized erythrocytes; ****P < 0.0001; Mann-Whitney test; n = 10–11/group). (C) BBB integrity was preserved in miR-155^−/− mice despite increased peripheral parasitemia. Median peripheral parasitemia at the time of Evans Blue assay was measured in miR-155^−/− and wild-type mice (****p < 0.0001; Mann-Whitney test; n = 10–11/group). Experiment was repeated for confirmation of findings. Error bars represent interquartile range.