Activation of mitogen-activated protein kinases in experimental cerebral ischemia.
OBJECTIVE
Mitogen-activated protein kinases (MAPK) regulate cell survival and differentiation. The aim of the present study is to investigate the activation pattern of different MAPKs [extracellular signal-regulated kinase (ERK), c-jun-N-terminal kinase (JNK) and p38] after cerebral ischemia.


METHODS
Rats were subjected to cerebral ischemia using a model for transient (2 h) and permanent middle cerebral artery occlusion (MCAO). The rats were allowed 6 h to 1 week of survival before immunohistochemical evaluation with phospho-specific antibodies, recognizing activated MAPKs.


RESULTS
ERK was activated in ipsilateral blood vessels, neurons and glia, but also in contralateral vessels. JNK activation was absent in neurons but appeared in arterial blood vessels and glia at the lesion side. Active p38 was observed in macrophages in maturing infarcts.


CONCLUSIONS
ERK and JNK may participate in the angiogenic response to cerebral ischemia. ERK, but not JNK, was activated in neurons, possibly indicating a pathophysiologic role. Active p38 might be involved in the inflammatory reaction.
Lennmyr
F
F
Department of Medical Sciences, Uppsala University Hospital, Uppsala, Sweden. fredrik.lennmyr@medsci.uu.se
Karlsson
S
S
Gerwins
P
P
Ata
K A
KA
Terént
A
A
D000818:Animals; D002545:Brain Ischemia / Q000401:mortality / Q000473:pathology* / Q000503:physiopathology*; D002536:Cerebral Arteries / Q000473:pathology; D002550:Cerebral Veins / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D004789:Enzyme Activation / Q000502:physiology*; D048031:JNK Mitogen-Activated Protein Kinases; D008264:Macrophages / Q000473:pathology; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000032:analysis / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology*; D009457:Neuroglia / Q000473:pathology; D009474:Neurons / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015996:Survival Rate; D048051:p38 Mitogen-Activated Protein Kinases
D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases