[The role of RKIP mediated ERK pathway in hippocampus neurons injured by electromagnetic radiation].
OBJECTIVE
To study the effects of electromagnetic radiation on RKIP and phosphorylated ERK in primary cultured hippocampus neurons. The inhibitor of MEK U0126 was applied to investigate the role of RKIP mediated ERK pathway in radiation injury.


METHODS
Primary hippocampus neurons were cultured in vitro. X-HPM, S-HPM and EMP were taken as radiation source respectively to establish three cell models exposed to electromagnetic radiation. RKIP and phosphorylated ERK were measured by immunofluorescent labelling and laser scanning confocal microscope. Apoptosis and death fraction of the cells were detected by Annexin V-PI double labelling and flow cytometry.


RESULTS
After three kinds of electromagnetic radiation, the expression of RKIP in hippocampus neurons decreased but the expression of phosphorylated ERK increased, and its nuclear translocation occurred. No significant differences were seen between radiation groups. Apoptosis and death fraction of the neurons in U0126 pretreatment groups was significantly lower than that in radiation groups but they were still higher than those in sham-radiation group.


CONCLUSIONS
The excessive activation of RKIP mediated ERK pathway is one of the important mechanisms for the apoptosis and death of hippocampus neurons induced by electromagnetic radiation. U0126 have some protective effects on radiation injury.
Zuo
Hong-Yan
HY
Institute of Radiation Medicine, Academy of Military Medical Science, Beijing 100850, China.
Wang
De-Wen
DW
Peng
Rui-Yun
RY
Wang
Shui-Ming
SM
Gao
Ya-Bing
YB
Zhang
Zhi-Yi
ZY
Xiao
Feng-Jun
FJ
D000818:Animals; D002070:Butadienes / Q000494:pharmacology; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D005434:Flow Cytometry; D006624:Hippocampus / Q000166:cytology*; D018613:Microscopy, Confocal; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects*; D009570:Nitriles / Q000494:pharmacology; D049488:Phosphatidylethanolamine Binding Protein / Q000378:metabolism*; D011827:Radiation; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects / Q000528:radiation effects*
D002070:Butadienes; D004791:Enzyme Inhibitors; D009570:Nitriles; D049488:Phosphatidylethanolamine Binding Protein; C113580:U 0126; D048049:Extracellular Signal-Regulated MAP Kinases