Astrocytes-Secreted WNT5B Disrupts the Blood-Brain Barrier Via ROR1/JNK/c-JUN Cascade During Meningitic Escherichia Coli Infection.

The blood-brain barrier (BBB) is a complex structure that separates the central nervous system (CNS) from the peripheral blood circulation. Effective communication between different cell types within the BBB is crucial for its proper functioning and maintenance of homeostasis. In this study, we demonstrate that meningitic Escherichia coli (E. coli)-induced WNT5B plays a role in facilitating intercellular communication between astrocytes and brain microvascular endothelial cells (BMECs). We discovered that astrocytes-derived WNT5B activates the non-canonical WNT signaling pathway JNK/c-JUN in BMECs through its receptor ROR1, leading to inhibition of ZO-1 expression and impairment of the tight junction integrity in BMECs. Notably, our findings reveal that c-JUN, a transcription factor, directly regulates ZO-1 expression. By employing a dual luciferase reporting system and chromatin immunoprecipitation techniques, we identified specific binding sites of c-JUN on the ZO-1 promoter region. Overall, our study highlights the involvement of WNT5B in mediating intercellular communication between astrocytes and BMECs, provides insights into the role of WNT5B in meningitic E. coli-induced disruption of BBB integrity, and suggests potential therapeutic targeting of WNT5B as a strategy to address BBB dysfunction.