Ischemic Mechanisms in Alzheimer's Disease

Alzheimer’s disease has traditionally been defined by the accumulation of β-amyloid plaques and tau tangles, but emerging evidence reveals vascular and ischaemic processes as critical contributors to its pathogenesis. Cerebral ischaemia—whether arising from stroke, transient hypoperfusion or microvascular dysfunction—triggers a cascade of events including breach of the blood–brain barrier, metabolic dysregulation in endothelial cells, oxidative stress and neuronal excitotoxicity. These processes amplify amyloidogenic and tau‐pathogenic pathways by enhancing secretase activity, impairing clearance mechanisms and promoting neuroinflammation. Consequently, ischaemic insults not only precipitate acute neuronal damage but also establish chronic changes in gene expression and protein trafficking that mirror, and potentially drive, hallmark features of Alzheimer’s disease. An integrated understanding of these ischaemic mechanisms offers new avenues for early detection and targeted intervention, with global significance for addressing dementia risk in populations burdened by vascular comorbidities.

Research from Nature Portfolio

Recent studies have elucidated the mechanistic link between vascular risk factors and Alzheimer’s disease. One investigation employing Mendelian randomisation has demonstrated that stroke mediates more than half of the hypertensive contribution to Alzheimer’s risk, highlighting cerebral ischaemia as a principal intermediary in this causal pathway. This finding underscores the potential of vascular control in mitigating Alzheimer’s onset.

Another line of research has uncovered a direct role for tau protein in post-ischaemic excitotoxic damage. Using an experimental stroke model, it was shown that absence of tau confers protection against glutamate-induced neuronal death by altering the synaptic distribution of the Ras-inhibiting protein SynGAP1. These insights link tau not only to classical neurofibrillary pathology but also to acute ischaemia-driven signalling that exacerbates neurodegeneration.

Ischemic Mechanisms in Alzheimer's Disease publication trend

The graph below shows the total number of articles in ischemic mechanisms in alzheimer's disease across all publications each year (not limited to Nature Index journals).

Technical terms

Ischaemia: Restriction of blood flow leading to deficient oxygen and glucose supply in brain tissue.

Blood–brain barrier (BBB): Semi-permeable interface composed of endothelial cells that controls entry of molecules from the circulation into the brain.

Amyloid β (Aβ): Peptide produced by proteolytic cleavage of amyloid precursor protein; aggregates into plaques in Alzheimer’s disease.

Tau: Microtubule-associated protein that, when abnormally phosphorylated, forms neurofibrillary tangles in Alzheimer’s disease.

Excitotoxicity: Neuronal cell death resulting from excessive activation of glutamate receptors following ischaemic injury.

References

1. Shared metabolic shifts in endothelial cells in stroke and Alzheimer’s disease revealed by integrated analysis. Scientific Data (2023).
2. LRP1 and RAGE Genes Transporting Amyloid and Tau Protein in the Hippocampal CA3 Area in an Ischemic Model of Alzheimer’s Disease with 2-Year Survival. Cells (2023).
3. Post-Ischemic Permeability of the Blood–Brain Barrier to Amyloid and Platelets as a Factor in the Maturation of Alzheimer’s Disease-Type Brain Neurodegeneration. International Journal of Molecular Sciences (2023).
4. Hypertension linked to Alzheimer’s disease via stroke: Mendelian randomization. Scientific Reports (2023).
5. Tau exacerbates excitotoxic brain damage in an animal model of stroke. Nature Communications (2017).