DIFFERENTIAL ACTIVATION OF p38 MAPKs IN MICROGLIA AND ASTROCYTES OF GERBIL BRAIN AFTER GLOBAL ISCHEMIA

초록

The p38 kinase, a member of the mitogen-activated protein kinase (MAPK), is abundantly expressed in adult brain. Several lines of evidences indicate that p38 MAPK activation is associated with pathological changes in the course of inflammatory and apoptotic processes in various cell types including neurons. Here we report the differential induction of p38α and p38β in adult gerbil brain following transient global ischemia. Immunoreactivity of p38α began to be induced as early as 4 hrs after ischemic insult and continued to increase reaching maximum induction around 4 days after ischemic insult. Induction of p38α immunoreactivity was enriched in the microglia in hippocampus as well as in frontal and parietal cortex of the brain, where significant neuronal damage was undergoing. In contrast, immunoreactivity for p38β was markedly induced in astrocytes in hippocampus 4 days after ischemic insult, which remained for next several days. Marked induction of p38 MAPKs following transient global ischemia, especially the differential induction of p38α and p38β MAPKs in microglia and astrocytes in different time point after ischemic insult indicates distinct roles of p38 MAPKs in post-ischemic brain.