Psychopharmacology

, Volume 214, Issue 3, pp 707–718

Inhibitory effects of alcohol on glucose transport across the blood–brain barrier leads to neurodegeneration: preventive role of acetyl-l-carnitine

  • P. M. Abdul Muneer
  • Saleena Alikunju
  • Adam M. Szlachetka
  • James Haorah
Original Investigation

DOI: 10.1007/s00213-010-2076-4

Cite this article as:
Muneer, P.M.A., Alikunju, S., Szlachetka, A.M. et al. Psychopharmacology (2011) 214: 707. doi:10.1007/s00213-010-2076-4

Abstract

Purpose

Evidence shows that alcohol intake causes oxidative neuronal injury and neurocognitive deficits that are distinct from the classical Wernicke-Korsakoff neuropathy. Our previous findings indicated that alcohol-elicited blood-brain barrier (BBB) damage leads to neuroinflammation and neuronal loss. The dynamic function of the BBB requires a constant supply and utilization of glucose. Here we examined whether interference of glucose uptake and transport at the endothelium by alcohol leads to BBB dysfunction and neuronal degeneration.

Material and methods

We tested the hypothesis in cell culture of human brain endothelial cells, neurons and alcohol intake in animal by immunofluorescence, Western blotting and glucose uptake assay methods.

Results

We found that decrease in glucose uptake correlates the reduction of glucose transporter protein 1 (GLUT1) in cell culture after 50 mM ethanol exposure. Decrease in GLUT1 protein levels was regulated at the translation process. In animal, chronic alcohol intake suppresses the transport of glucose into the frontal and occipital regions of the brain. This finding is validated by a marked decrease in GLUT1 protein expression in brain microvessel (the BBB). In parallel, alcohol intake impairs the BBB tight junction proteins occludin, zonula occludens-1, and claudin-5 in the brain microvessel. Permeability of sodium fluorescein and Evans Blue confirms the leakiness of the BBB. Further, depletion of trans-endothelial electrical resistance of the cell monolayer supports the disruption of BBB integrity. Administration of acetyl-l-carnitine (a neuroprotective agent) significantly prevents the adverse effects of alcohol on glucose uptake, BBB damage and neuronal degeneration.

Conclusion

These findings suggest that alcohol-elicited inhibition of glucose transport at the blood-brain interface leads to BBB malfunction and neurological complications.

Keywords

Blood–brain barrierGlucose transporter proteinTrans-endothelial electrical resistanceAcetyl-l-carnitineTight junctionNeurodegeneration

Abbreviations

ALC

Acetyl-l-carnitine

act-D

Actinomycin D

BBB

Blood–brain barrier

CB

Cytochalasin B

ChAT

Choline acetyltransferase

Chx

Cycloheximide

DMSO

Dimethyl sulfoxide

EB

Evans Blue

EtOH

Ethanol

GFAP

Glial fibrillar acidic protein

GLUT

Glucose transporter protein

hBECs

Human brain endothelial cells

MTT

3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide

NaFl

Sodium fluorescein

NF

Neurofilament

TEER

Trans-endothelial electrical resistance

TH

Tyrosine hydroxylase

vWF

von Willebrand factor

ZO-1

Zonula occludens-1

Copyright information

© Springer-Verlag (outside the USA) 2010

Authors and Affiliations

  • P. M. Abdul Muneer
    • 1
  • Saleena Alikunju
    • 1
  • Adam M. Szlachetka
    • 1
  • James Haorah
    • 1
  1. 1.Laboratory of Neurovascular Oxidative Injury, Department of Pharmacology and Experimental NeuroscienceUniversity of Nebraska Medical CenterOmahaUSA