First Author | Gong B | Year | 2013 |
Journal | Mol Immunol | Volume | 56 |
Issue | 4 | Pages | 619-29 |
PubMed ID | 23911420 | Mgi Jnum | J:202095 |
Mgi Id | MGI:5517487 | Doi | 10.1016/j.molimm.2013.06.016 |
Citation | Gong B, et al. (2013) IVIG immunotherapy protects against synaptic dysfunction in Alzheimer's disease through complement anaphylatoxin C5a-mediated AMPA-CREB-C/EBP signaling pathway. Mol Immunol 56(4):619-29 |
abstractText | BACKGROUND: Complement component C5-derived C5a locally generated in the brain has been shown to protect against glutamate-induced neuronal apoptosis and beta-amyloid (Abeta) toxicity, but the mechanism is not clear. In this study, we tested the hypothesis that C5a influences upstream signal transduction pathways associated with cAMP-response element-binding protein (CREB) activation, in which alterations of CREB levels are associated with cognitive deterioration in AD. METHODS: CREB signaling pathway, synaptic plasticity and cognitive function were studied in C5a receptor knockout mice (C5aR(-/-)), C5a over expressing mice (C5a/GFAP) and in Tg2576 mice, an AD mouse model. RESULTS: (1) Cognitive function is severely impaired in C5aR(-/-) mice, coincident with the down-regulated CREB/CEBP pathway in brain. (2) Either the application of recombinant-human-C5a (hrC5a) or exogenous expression of C5a in the brain of a mouse model (C5a/GFAP) enhances this pathway. (3) Application of hrC5a in brain slices from Tg2576 mice significantly improves deficits in long-term potentiation (LTP), while this effect is blocked by a specific AMPA receptor antagonist. (4) Searching for a pharmacological approach to locally mediate C5a responses in the brain, we found that low-dose human intravenous immunoglobulin (IVIG) treatment improves synaptic plasticity and cognitive function through C5a-mediated induction of the CREB/CEBP pathway, while the levels of Abeta in the brain are not significantly affected. CONCLUSION: This study for the first time provides novel evidence suggesting that C5a may beneficially influence cognitive function in AD through an up-regulation of AMPA-CREB signaling pathway. IVIG may systematically improve cognitive function in AD brain by passing Abeta toxicity. |