ERK1/2 activation in reactive astrocytes of mice with pilocarpine-induced status epilepticus.
OBJECTIVE
To investigate the activation pattern of extracellular signal-regulated kinase 1/2 (ERK1/2) in the hippocampus of mice during pilocarpine-induced status epilepticus (SE) and its relationship with reactive astrogliosis.


METHODS
Status epilepticus (SE) models were established by intraperitoneal injection of pilocarpine. The intervention group received the ERK1/2 signaling pathway inhibitor SL327 before the pilocarpine injection. We evaluated the SE model group, the intervention group and the control saline-treated group, at 6 hours and 3 days after initiation of the seizure. Phosphorylated activated ERK1/2 and glial fibrillary acidic protein (GFAP) were labeled with both single-labeling and sequential single-labeling immunohistochemical techniques.


RESULTS
Among the pilocarpine-treated (SE model) mice, strong immunohistochemical staining of phospho-ERK1/2 was observed in the neurons and astrocytes of the hippocampus at 6 hours after initiation of SE, whereas staining on the third day of SE was not different from the control saline-treated mice. In the SL327-treated mice (intervention group), SL327 effectively blocked the ERK1/2 activation and little gliosis could be detected at 6 hours and 3 days after initiation of SE; the levels of phospho-ERK1/2 remained low, but the level of gliosis was similar to that of SE mice.


CONCLUSIONS
The ERK1/2 signaling pathway plays an important role in the early stage of reactive astrogliosis in mice with pilocarpine-induced SE.
Li
Yu-Qin
YQ
Department of Neurology, Second Affiliated Hospital, Chongqing Medical University, Linjiang Road 76, Chongqing 400010, China.
Xue
Tao
T
Xu
Jing
J
Xu
Zu-Cai
ZC
Liu
Hua
H
Chen
Yang-Mei
YM
D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D002452:Cell Count; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D005911:Gliosis / Q000378:metabolism* / Q000473:pathology; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D010766:Phosphorylation; D010862:Pilocarpine / Q000494:pharmacology*; D011897:Random Allocation; D015398:Signal Transduction / Q000502:physiology; D013226:Status Epilepticus / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D013997:Time Factors
D005904:Glial Fibrillary Acidic Protein; D010862:Pilocarpine; D048052:Mitogen-Activated Protein Kinase 3