Fig. 4.

Mertk knockout mice exhibited impaired blood–brain-barrier integrity under JEV challenging condition. A BBB permeability was measured in terms of NaF accumulation in brain of WT and Mertk^−/− mice at 4 days (PBS-treated WT n = 7, PBS-treated Mertk^−/− n = 8, JEV-treated WT n = 11, JEV-treated Mertk^−/− n = 11) after JEV infection. B Knockdown of Mertk in BEnd.3 cell line using lentiviral expression system were in identified by qPCR. C Graphical representation of in vitro BBB model. D Normalized TEER values of BBB model were monitored per day to reveal BBB integrity. E Immunofluorescence analysis of CD31 and ZO-1 expression in mice brain at 5 days after PBS or JEV infected WT and Mertk^−/− mice. Endothelium stained by CD31 antibody is displayed in red, ZO-1 is displayed in green, the nucleus stained with DAPI is shown in blue. Scale bar: 20 μm. F Quantitative analysis of CD31 and ZO-1 expression in WT and Mertk^−/− mice infected with JEV. *P < 0.05, **P < 0.01 and ***P < 0.001