GLUT1 reductions exacerbate Alzheimer's disease vasculo-neuronal dysfunction and degeneration

Area of Science:

• Neuroscience
• Vascular Biology
• Metabolic Disorders

Background:

• Glucose transporter GLUT1 facilitates brain glucose uptake at the blood-brain barrier (BBB).
• Alzheimer's disease (AD) is linked to reduced brain glucose transport and diminished GLUT1 expression at the BBB.
• The precise role of GLUT1 reduction in AD pathogenesis is not fully understood.

Purpose of the Study:

• To investigate the impact of GLUT1 deficiency on Alzheimer's disease progression.
• To determine if GLUT1 reduction influences cerebrovascular integrity and neuropathology in AD models.
• To identify the cellular source of GLUT1 responsible for initiating vascular dysfunction.

Main Methods:

• Utilized a mouse model overexpressing amyloid precursor protein (APP) with induced GLUT1 deficiency.
• Assessed cerebral microvascular integrity, blood flow, and BBB permeability.
• Evaluated amyloid-beta (Aβ) pathology, neuronal activity, cognitive function, and neurodegeneration.

Main Results:

• GLUT1 deficiency in APP mice caused early cerebral microvascular degeneration, BBB breakdown, and reduced blood flow.
• Reduced GLUT1 expression accelerated Aβ pathology, impaired Aβ clearance, and diminished neuronal activity.
• Endothelial GLUT1 deficiency, not astrocytic, initiated the observed vascular phenotype and BBB breakdown.
• These vascular changes preceded and contributed to neurodegeneration and cognitive deficits.

Conclusions:

• Reduced GLUT1 expression at the BBB exacerbates Alzheimer's disease-related cerebrovascular degeneration, neuropathology, and cognitive impairment.
• Endothelial GLUT1 is critical for maintaining BBB integrity and preventing vascular dysfunction in AD.
• Targeting GLUT1 represents a potential therapeutic strategy for Alzheimer's disease vasculo-neuronal dysfunction.