title: Elevated neuronal α-synuclein promotes microglia activation after spinal cord ischemic/reperfused injury.
abstract: The present study aimed to investigate the mechanism of injured neurons caused by ischemia/reperfusion in the induction of microglia activation. Spinal neurons were prepared and exposed to ischemic/reperfused conditions. The α-synuclein protein levels in these cells were analyzed by western blot, immunofluorescence, or enzyme-linked immunosorbent assay. Ischemia/reperfusion exposure led to elevated α-synuclein protein expression and release. Furthermore, when cocultured with injured neurons or supernatants from injured neurons, nitric oxide generation, H2O2 production, and tumor necrosis factor-α expression were promoted in microglia. Nevertheless, this effect was impeded by pretreatment of the α-synuclein antibody in the supernatants from injured neurons. Moreover, toll-like receptor 2 (TLR2) rather than TLR3 or TLR4 mediated microglia activation by α-synuclein. This process involved p38 MAPK and NF-κB activation, the inhibition of which resulted in reduced NADPH oxidase 2 (Nox2) in microglia. In conclusion, ischemia/reperfusion-injured neurons could express and release increased levels of α-synuclein and cause microglia activation through TLR2 both in vitro and in vivo.
authors.affiliation: Departments of aRehabilitation Medicine bOrthopedics, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Hongfei
authors.initials: H
authors.lastname: Qiao
authors.forename: Qiaojun
authors.initials: Q
authors.lastname: Zhang
authors.forename: Haifeng
authors.initials: H
authors.lastname: Yuan
authors.forename: Yali
authors.initials: Y
authors.lastname: Li
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.forename: Xijing
authors.initials: X
authors.lastname: He
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000906:Antibodies / Q000494:pharmacology; D002478:Cells, Cultured; D018920:Coculture Techniques; D004622:Embryo, Mammalian; D004797:Enzyme-Linked Immunosorbent Assay; D005786:Gene Expression Regulation; D006861:Hydrogen Peroxide / Q000378:metabolism; D007511:Ischemia / Q000378:metabolism / Q000473:pathology*; D017628:Microglia / Q000187:drug effects / Q000378:metabolism*; D009474:Neurons / Q000201:enzymology*; D009569:Nitric Oxide / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology*; D013116:Spinal Cord / Q000166:cytology*; D013997:Time Factors; D051195:Toll-Like Receptor 2 / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D051844:alpha-Synuclein / Q000276:immunology / Q000378:metabolism*
chemical_list: D000906:Antibodies; C495343:Tlr2 protein, rat; D051195:Toll-Like Receptor 2; D014409:Tumor Necrosis Factor-alpha; D051844:alpha-Synuclein; D009569:Nitric Oxide; D006861:Hydrogen Peroxide