Fig. 7.

APOE isoforms influence the time course of BBB dysfunction following TBI. Diagram summarizing the time course of TBI-induced BBB disruption, stabilization and closure in Wildtype, APOE3 and APOE4 mice. Despite Wildtype, APOE3 and APOE4 mice all displaying similar acute BBB responses to TBI, such as elevated permeability and pericyte loss, APOE4 mice display a significantly extended period of BBB leakage following injury. This enhanced time-course of BBB permeability in APOE4 mice occurs in parallel with reduced pericyte repopulation back to the NVU after injury, as well as sustained MMP-9 responses that may cumulatively contribute to the prolonged levels of tight junction degradation