TJP1 and escherichia coli infection: Since astrocytes-derived TGFβ1 exhibited an endothelial barrier protective effect, while our early studies and data in this work (Fig. 1) supported the disruptive outcomes of the endothelial barrier caused by meningitic E. coli infection [21, 29], then there come the questions that whether and how meningitic E. coli hijacks this TGFβ1-mediated barrier-maintaining pathway (TGFβ1-TGFBRI/II-Smads-Gli1/2-ZO-1 axis) for its BBB penetration.