Aspirin inhibits cytotoxicity of prion peptide PrP106-126 to neuronal cells associated with microglia activation in vitro.
The synthetic peptide consisting of amino acid residues 106-126 of the human prion protein PrP106-126 has been demonstrated to generate fibrils, which damage neurons either directly by interacting with components of the cell surface to trigger cell apoptosis signaling or indirectly by activating microglia to produce inflammatory mediators. In our study, rat microglia cells were treated with PrP106-126 or scramble PrP106-126 (Scr PrP). Activated nuclear factor kappaB (NF-kappaB) was determined using immunofluorescence staining and the expression of TNF-alpha and IL-1beta mRNA was measured by quantitative RT-PCR. Inhibitory activity of aspirin on neurotoxicity of PrP106-126 associated with microglia activation was determined using an apoptosis detection kit. Treatment of microglia with 25 microM PrP106-126, but not Scr PrP, resulted in activation and translocation of NF-kappaB, which peaked after 20 min of treatment. The activation of NF-kappaB was followed by increased mRNA expression of TNF-alpha and IL-1beta peaking at about 20 h. In the presence of microglia, aspirin significantly inhibited neuro-2a cell death induced by PrP106-126. The number of neuro-2a cells in apoptosis and necrosis with 5 mM aspirin was about 3-fold lower than the cell culture without aspirin (P<0.05). These data suggest that increased production of cytokines by microglia cells in prion disease is probably regulated by NF-kappaB translocation and may contribute to neurotoxicity of prions, and neurotoxicity of PrP106-126 may be inhibited by aspirin.
National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China.
Lifeng
L
Yang
Xiangmei
X
Zhou
Jianmin
J
Yang
Xiaomin
X
Yin
Lifang
L
Han
Deming
D
Zhao
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001241:Aspirin / Q000494:pharmacology*; D002478:Cells, Cultured; D006801:Humans; D066298:In Vitro Techniques; D053583:Interleukin-1beta / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D017628:Microglia / Q000378:metabolism*; D016328:NF-kappa B / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000473:pathology; D010446:Peptide Fragments / Q000187:drug effects* / Q000633:toxicity; D011328:Prions / Q000187:drug effects* / Q000633:toxicity; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000187:drug effects / Q000378:metabolism
D000894:Anti-Inflammatory Agents, Non-Steroidal; D053583:Interleukin-1beta; D016328:NF-kappa B; D010446:Peptide Fragments; D011328:Prions; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; C082632:prion protein (106-126); D001241:Aspirin