Blood-Brain Barrier Dysfunction in Diabetes Mellitus

Diabetes mellitus exerts profound effects on the cerebral microvasculature, undermining the structural and functional integrity of the blood–brain barrier (BBB). Sustained hyperglycaemia induces endothelial oxidative stress, inflammatory signalling and accumulation of advanced glycation end products, collectively disrupting tight junctions and increasing barrier permeability. Concurrent pericyte loss and basement membrane thickening destabilise the neurovascular unit, permitting peripheral immune cells and circulating neurotoxins to enter the brain parenchyma. These vascular alterations impair waste clearance, exacerbate neuroinflammation and accelerate neurodegenerative processes, manifesting as cognitive decline and elevated dementia risk. Insights into the molecular and cellular drivers of BBB dysfunction in diabetes are essential for designing interventions to safeguard cerebral health in a global population facing rising rates of metabolic disease.

Research from Nature Portfolio

Recent ex vivo and in vitro studies demonstrate that exposure of brain microvessels to hyperglycaemic conditions or advanced glycation end products disrupts endothelial tight junction architecture and promotes secretion of occludin and claudin-5 in extracellular vesicles, while elevating leukocyte adhesion and barrier permeability. In leptin receptor-deficient mice, early transient BBB leakage occurs before overt hyperglycaemia, with ultrastructural evidence of mitochondrial degeneration and endothelial stress suggesting that barrier compromise can precede sustained high glucose. Moreover, genetic models of chronic hyperglycaemia reveal preserved barrier integrity despite prolonged glucose elevation, indicating that BBB dysfunction may be stage-specific or driven by inflammatory mediators rather than hyperglycaemia alone.

Blood-Brain Barrier Dysfunction in Diabetes Mellitus publication trend

The graph below shows the total number of articles in blood-brain barrier dysfunction in diabetes mellitus across all publications each year (not limited to Nature Index journals).

Technical terms

Blood–Brain Barrier (BBB): A selective endothelial interface regulating substance exchange between the bloodstream and the central nervous system.

Tight junctions: Protein complexes between endothelial cells that maintain barrier impermeability.

Advanced glycation end products (AGEs): Reactive molecules formed by non-enzymatic glycation of proteins and lipids under hyperglycaemic conditions, which trigger inflammation and oxidative damage.

Pericytes: Contractile cells surrounding capillaries that support vascular stability and regulate barrier permeability.

Neurovascular coupling: Dynamic interactions among neurons, glia and blood vessels that match cerebral blood flow to neuronal activity.

References

1. Effects of Diabetes Mellitus-Related Dysglycemia on the Functions of Blood–Brain Barrier and the Risk of Dementia. International Journal of Molecular Sciences (2023).
2. BMECs Ameliorate High Glucose-Induced Morphological Aberrations and Synaptic Dysfunction via VEGF-Mediated Modulation of Glucose Uptake in Cortical Neurons. Cellular and Molecular Neurobiology (2023).
3. Hyperglycemia and advanced glycation end products disrupt BBB and promote occludin and claudin-5 protein secretion on extracellular microvesicles. Scientific Reports (2020).
4. Leptin receptor deficiency induces early, transient and hyperglycaemia-independent blood-brain barrier dysfunction. Scientific Reports (2019).
5. Prolonged systemic hyperglycemia does not cause pericyte loss and permeability at the mouse blood-brain barrier. Scientific Reports (2018).