title: Electromagnetic pulse activated brain microglia via the p38 MAPK pathway.
abstract: Previously, we found that electromagnetic pulses (EMP) induced an increase in blood brain barrier permeability and the leakage of albumin from blood into brain tissue. Albumin is known to activate microglia cells. Thus, we hypothesised that microglia activation could occur in the brain after EMP exposure. To test this hypothesis, the morphology and secretory function of microglia cells, including the expression of OX-42 (a marker of microglia activation), and levels of TNF-α, IL-10, IL-1β, and NO were determined in the rat cerebral cortex after EMP exposure. In addition, to examine the signalling pathway of EMP-induced microglia activation, protein and phosphorylated protein levels of p38, JNK and ERK were determined. It was found that the expression of OX-42increased significantly at 1, 6 and 12h (p<0.05) and recovered to the sham group level at 24h after EMP exposure. Levels of NO, TNF-α and IL-10 also changed significantly in vivo and in vitro after EMP exposure. The protein level of p38 and phosphorylated p38 increased significantly after EMP exposure (p<0.05) and recovered to sham levels at 12 and 24h, respectively. Protein and phosphorylated protein levels of ERK and JNK did not change. SB203580 (p38 inhibitor) partly prevented the change in NO, IL-10, IL-1β, TNF-α levels induced by EMP exposure. Taken together, these results suggested that EMP exposure (200kV/m, 200 pulses) could activate microglia in rat brain and affect its secretory function both in vivo and in vitro, and the p38 pathway is involved in this process.
authors.affiliation: Department of Radiation Biology, School of Public Health, Fourth Military Medical University, 169 Changle West Road, Xi'an, Shaanxi 710032, China; Department of Radiation Medicine, School of Public Health, Fourth Military Medical University, 169 Changle West Road, Xi'an, Shaanxi 710032, China.
authors.forename: Long-Long
authors.initials: LL
authors.lastname: Yang
authors.affiliation: Department of Radiation Biology, School of Public Health, Fourth Military Medical University, 169 Changle West Road, Xi'an, Shaanxi 710032, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Neurosurgery, Laiyang Central Hospital of Yantai, Laiyang, Shandong 265200, China.
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Tian
authors.affiliation: Department of Radiation Medicine, School of Public Health, Fourth Military Medical University, 169 Changle West Road, Xi'an, Shaanxi 710032, China.
authors.forename: Hai-Juan
authors.initials: HJ
authors.lastname: Li
authors.affiliation: Department of Radiation Biology, School of Public Health, Fourth Military Medical University, 169 Changle West Road, Xi'an, Shaanxi 710032, China.
authors.lastname: Kang-Chu-Li
authors.affiliation: Department of Radiation Biology, School of Public Health, Fourth Military Medical University, 169 Changle West Road, Xi'an, Shaanxi 710032, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Miao
authors.affiliation: Department of Radiation Biology, School of Public Health, Fourth Military Medical University, 169 Changle West Road, Xi'an, Shaanxi 710032, China.
authors.forename: Guang-Zhou
authors.initials: GZ
authors.lastname: An
authors.affiliation: Department of Radiation Medicine, School of Public Health, Fourth Military Medical University, 169 Changle West Road, Xi'an, Shaanxi 710032, China.
authors.forename: Xiao-Wu
authors.initials: XW
authors.lastname: Wang
authors.affiliation: Department of Radiation Medicine, School of Public Health, Fourth Military Medical University, 169 Changle West Road, Xi'an, Shaanxi 710032, China. Electronic address: guozhen@fmmu.edu.cn.
authors.forename: Guo-Zhen
authors.initials: GZ
authors.lastname: Guo
authors.affiliation: Department of Radiation Biology, School of Public Health, Fourth Military Medical University, 169 Changle West Road, Xi'an, Shaanxi 710032, China. Electronic address: dingzhao@fmmu.edu.cn.
authors.forename: Gui-Rong
authors.initials: GR
authors.lastname: Ding
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000166:cytology*; D004574:Electromagnetic Fields / Q000009:adverse effects*; D007093:Imidazoles / Q000494:pharmacology; D016753:Interleukin-10 / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008297:Male; D017628:Microglia / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D061251:Primary Cell Culture; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: C000594089:IL1B protein, rat; D007093:Imidazoles; D053583:Interleukin-1beta; D011725:Pyridines; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D009569:Nitric Oxide; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580
keywords: Brain; Electromagnetic pulse; MAPK pathway; Microglia