Neurotrophic signaling deficiency exacerbates environmental risks for Alzheimer's disease pathogenesis.
Proc Natl Acad Sci U S A
; 118(25)2021 06 22.
Article
em En
| MEDLINE
| ID: mdl-34140411
ABSTRACT
The molecular mechanism of Alzheimer's disease (AD) pathogenesis remains obscure. Life and/or environmental events, such as traumatic brain injury (TBI), high-fat diet (HFD), and chronic cerebral hypoperfusion (CCH), are proposed exogenous risk factors for AD. BDNF/TrkB, an essential neurotrophic signaling for synaptic plasticity and neuronal survival, are reduced in the aged brain and in AD patients. Here, we show that environmental factors activate C/EBPß, an inflammatory transcription factor, which subsequently up-regulates δ-secretase that simultaneously cleaves both APP and Tau, triggering AD neuropathological changes. These adverse effects are additively exacerbated in BDNF+/- or TrkB+/- mice. Strikingly, TBI provokes both senile plaque deposit and neurofibrillary tangles (NFT) formation in TrkB+/- mice, associated with augmented neuroinflammation and extensive neuronal loss, leading to cognitive deficits. Depletion of C/EBPß inhibits TBI-induced AD-like pathologies in these mice. Remarkably, amyloid aggregates and NFT are tempospatially distributed in TrkB+/- mice brains after TBI, providing insight into their spreading in the progression of AD-like pathologies. Hence, our study revealed the roles of exogenous (TBI, HFD, and CCH) and endogenous (TrkB/BDNF) risk factors in the onset of AD-associated pathologies.
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MEDLINE
Assunto principal:
Transdução de Sinais
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Progressão da Doença
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Meio Ambiente
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Doença de Alzheimer
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Fatores de Crescimento Neural
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article