Blood-Brain Barrier Dynamics in Alzheimer's Disease

The blood–brain barrier (BBB) is a highly specialised endothelial interface that regulates molecular and cellular traffic between the circulation and the central nervous system. In Alzheimer’s disease, the dynamic regulation of barrier permeability, transcytotic pathways and receptor-mediated clearance of neurotoxic peptides becomes impaired, contributing to cerebral amyloid-β (Aβ) accumulation and neuroinflammation. Endothelial cells, pericytes and astrocytic end-feet coordinate to maintain BBB integrity through tight junction proteins and active transport mechanisms. Dysregulation of receptors such as low-density lipoprotein receptor-related protein 1 (LRP1) at the luminal and abluminal membranes perturbs Aβ efflux, while altered signalling within endothelial cells and pericyte loss exacerbate leakage of plasma proteins and peripheral immune cells. Blood-borne factors—including grancalcin-expressing immune subsets—can further compromise barrier function by interfering with receptor-mediated clearance. The resultant chronic barrier breakdown not only accelerates plaque formation and tau pathology but also drives microglial activation and cytokine release, establishing a feed-forward loop of neuronal injury. Understanding the balance between barrier disruption and compensatory repair pathways is central to developing strategies aimed at restoring vascular clearance of Aβ, reinforcing tight junction integrity and modulating immune trafficking. Therapeutic approaches under investigation range from gene therapies restoring receptor function to nanocarrier systems exploiting residual transcytosis routes, all with the aim of re-establishing selective permeability while preventing inadvertent neurotoxic influx.

Research from Nature Portfolio

Recent studies have revealed that endothelial expression of ANKS1A is essential for surface targeting of LRP1 and efficient Aβ clearance. Loss of ANKS1A in animal models leads to diminished LRP1-mediated transcytosis, aggravated amyloid burden and cognitive decline, effects that are reversible upon endothelial-specific gene restoration. In parallel, stem cell-derived in vitro barrier models lacking ANKS1A demonstrate reduced Aβ export, underscoring a mechanistic link between adaptor proteins, receptor trafficking and barrier-mediated peptide clearance.

Blood-Brain Barrier Dynamics in Alzheimer's Disease publication trend

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

Technical terms

Blood–Brain Barrier (BBB): A specialised vascular interface formed by endothelial cells, pericytes and astrocyte end-feet that regulates transport between blood and brain.

Low-Density Lipoprotein Receptor-Related Protein 1 (LRP1): A multifunctional endocytic receptor expressed on endothelial cells and microglia, crucial for amyloid-β transcytosis and clearance.

Amyloid-β (Aβ): Peptide fragments derived from amyloid precursor protein that aggregate into plaques, a hallmark of Alzheimer’s pathology.

Transcytosis: The vesicular transport process by which molecules are shuttled across endothelial cells from the blood to the brain or vice versa.

References

1. ANKS1A regulates LDL receptor-related protein 1 (LRP1)-mediated cerebrovascular clearance in brain endothelial cells. Nature Communications (2023).
2. Bone Marrow‐Derived GCA+ Immune Cells Drive Alzheimer's Disease Progression. Advanced Science (2023).
3. Peripheral amyloid-β clearance mediates cognitive impairment in non-alcoholic fatty liver disease. EBioMedicine (2024).
4. β-Amyloid targeting nanodrug for neuron-specific delivery of nucleic acids in Alzheimer's disease mouse models. Journal of Controlled Release (2023).