Targeting BACE1-mediated production of amyloid beta improves hippocampal synaptic function in an experimental model of ischemic stroke

Abstract

Post-stroke cognitive impairment and dementia (PSCID) affects many survivors of large vessel cerebral ischemia. The molecular pathways underlying PSCID are poorly defined but may overlap with neurodegenerative pathophysiology. Specifically, synaptic dysfunction after stroke may be directly mediated by alterations in the levels of amyloid beta (Aβ), the peptide that accumulates in the brains of Alzheimer’s disease (AD) patients. In this study, we use the transient middle cerebral artery occlusion (MCAo) model in young adult mice to evaluate if a large vessel stroke increases brain soluble Aβ levels. We show that soluble Aβ40 and Aβ42 levels are increased in the ipsilateral hippocampus in MCAo mice 7 days after the injury. We also analyze the level and activity of β-site amyloid precursor protein cleaving enzyme 1 (BACE1), an enzyme that generates Aβ in the brain, and observe that BACE1 activity is increased in the ipsilateral hippocampus of the MCAo mice. Finally, we highlight that treatment of MCAo mice with a BACE1 inhibitor during the recovery period rescues stroke-induced deficits in hippocampal synaptic plasticity. These findings support a molecular pathway linking ischemia to alterations in BACE1-mediated production of Aβ, and encourage future studies that evaluate whether targeting BACE1 activity improves the cognitive deficits seen with PSCID.

Melatonin Inhibits Hypoxia-Induced Alzheimer’s Disease Pathogenesis by Regulating the Amyloidogenic Pathway in Human Neuroblastoma Cells

“…BACE1 is a crucial enzyme in Aβ synthesis, and its mRNA and protein levels increase after ischemic stroke [62]. To investigate the effects of hypoxia on the BACE1 promoter, we used a reporter assay.…”

Recognizing Alzheimer's disease from perspective of oligodendrocytes: Phenomena or pathogenesis?

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Post-stroke cognitive impairment: exploring molecular mechanisms and omics biomarkers for early identification and intervention

“…In addition, Enterobacteriaceae , one of the microorganisms, metabolizes lipopolysaccharide, which not only leads to the release of pro-inflammatory factors, but also leads to the deposition of β-amyloid ( Płóciennikowska et al, 2015 ). Most animal studies have shown that β-amyloid is often deposited in the thalamus after stroke ( van Groen et al, 2005 ; Mäkinen et al, 2008 ; Zhang J. et al, 2012 ), while other studies have found that β-amyloid is deposited in the hippocampus ( Dietrich et al, 1998 ; Basak et al, 2023 ). It is well known that the thalamic nuclei play an important role in cognitive function ( Dalrymple-Alford et al, 2015 ), and the hippocampus is closely related to the thalamic nuclei ( Braak et al, 1996 ).…”