Fig. 8.

Blood VTN leaks into the brain after stroke. (A) Schematic showing an overview of the signaling pathway by which VTN induces LIF and IL-6 gene expression, by binding to αvβ3 integrin and specifically activating downstream FAK. (B) Proposed model of VTN leakage after blood–brain barrier (BBB) breakdown. Under normal conditions, the intact BBB, characterized by tight junctions (TJ) between endothelial cells (EC), keeps VTN in blood from entering the central nervous system (CNS) tissue. BM, basement membrane. Under pathological conditions that cause BBB breakdown, such as stroke and hemorrhage, leakage of VTN in the brain parenchyma induces LIF and IL-6 expression by astrocytes (gray cells), microglia (blue cells) and endothelial cells (green cells).