title: Cooperative expression of survival p-ERK and p-Akt signals in rat brain neurons after transient MCAO.
abstract: In order to determine possible coordinate expression of major survival signals, immunofluorescent analyses for phosphorylated ERK (p-ERK) and phosphorylated Akt (p-Akt) were carried out after 90 min of transient middle cerebral artery occlusion (MCAO) in rats. p-Akt single positive cells (E-/A+) were found in the sham control brains with weak signal intensity. The levels of both survival signals concurrently increased from 1 to 3 h after the reperfusion with the peak at 1 h, and the signals were much stronger in the ischemic penumbra (IP) than ischemic core (IC). The number of E-/A+ cells was larger in both the IC and IP than that of p-ERK single positive cells (E+/A-). The E+/A- cells were primarily expressed at 1 h in the IP. The number of p-ERK plus p-Akt double positive cells (E+/A+) peaked at 1 h, and the intensity was much stronger in the IP than IC. These findings suggest that p-ERK and p-Akt play independent roles, respectively as emergency or maintenance signal for survival at an early stage after reperfusion, and that both signals were cooperatively expressed especially in the IP.
authors.affiliation: Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, 2-5-1 Shikatacho, Okayama 700-8558, Japan.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Omori
authors.forename: Guang
authors.initials: G
authors.lastname: Jin
authors.forename: Shao Jun
authors.initials: SJ
authors.lastname: Wang
authors.forename: Keiko
authors.initials: K
authors.lastname: Sato
authors.forename: Isao
authors.initials: I
authors.lastname: Nagano
authors.forename: Mikio
authors.initials: M
authors.lastname: Shoji
authors.forename: Koji
authors.initials: K
authors.lastname: Abe
mesh_terms: D000818:Animals; D001921:Brain / Q000201:enzymology*; D005455:Fluorescent Antibody Technique; D002546:Ischemic Attack, Transient / Q000201:enzymology*; D008297:Male; D020768:Middle Cerebral Artery; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009474:Neurons / Q000201:enzymology*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt; D051381:Rats; D017208:Rats, Wistar
chemical_list: D011518:Proto-Oncogene Proteins; D011505:Protein-Tyrosine Kinases; C494920:Akt1 protein, rat; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D020928:Mitogen-Activated Protein Kinases