Title : Astrocyte Reactivation is Concerned in BBB Recovery from Breakdown
Brain is not easy to cure when it has damage or inflammation occurs, because neurons are never regenerate after the degeneration. We have been focusing on one of the glial cells, astrocytes which has the important role in the central nervous system to transfer some of the nutrition or Ca2+ signaling between neurons and blood vessels. However, astrocytes become active when the brain had injury or inflammation though the functional significance of the astrocytic activation is not yet clarified. To examine the functional role of reactive astrocytes, we used some of the gene deficient mice with stab wound injury on the cerebral cortex with needle from rostral to caudal axis. By the immuno-fluorescent analysis on the brain sections using antibody against bromo-deoxy-uridine for proliferating cells, GFAP for astrocytes, Iba1 for microglial cells, and IgG for blood brain barrier breakdown, IgG leakage level and reactivation level was almost correlated. Furthermore, expression levels of some molecules concerned in the BBB integrity was well paralleled to IgG leakage. From these results, reactivation of astrocytes might be concerned in recovery of BBB breakdown caused by stab wound injury to the brain.