TJP1 and nervous system disorder: This investigation substantiates the notion that the circRNA-PTPN4/miR-301a-3p/FOXO3 axis plays a crucial role in modulating BBB function by regulating the expression of ZO-1, thus offering new insights into the mechanistic involvement of ncRNAs, particularly circRNAs, in cellular signal transduction and providing a novel model for understanding the complex dynamics of BBB integrity and neurological diseases.