Articles tagués bbb

Role of CCL2 (MCP-1) in traumatic brain injury (TBI): evidence from severe TBI patients and CCL2−/− mice

Role of CCL2 (MCP-1) in traumatic brain injury (TBI): evidence from severe TBI patients and CCL2−/− mice

Bridgette D Semple, Nicole Bye, Mario Rancan, Jenna M Ziebell and M Cristina Morganti-Kossmann

Journal of Cerebral Blood Flow & Metabolism advance online publication 23 December 2009; doi: 10.1038/jcbfm.2009.262

Lire la suite »

Publicités

, , , , ,

Poster un commentaire

VEGF-induced BBB permeability is associated with an MMP-9 activity increase in cerebral ischemia: both effects decreased by Ang-1

VEGF-induced BBB permeability is associated with an MMP-9 activity increase in cerebral ischemia: both effects decreased by Ang-1

Samuel Valable, Joan Montaner, Anita Bellail, Vincent Berezowski, Julien Brillault, Romeo Cecchelli, Didier Divoux, Eric T MacKenzie, Myriam Bernaudin, Simon Roussel and Edwige Petit

Journal of Cerebral Blood Flow & Metabolism (2005) 25, 1491–1504. doi:10.1038/sj.jcbfm.9600148

Lire la suite »

, , , , ,

Poster un commentaire

Vascular endothelial growth factor (VEGF) modulates vascular permeability and inflammation in rat brain.

Vascular endothelial growth factor (VEGF) modulates vascular permeability and inflammation in rat brain.

Proescholdt MA, Heiss JD, Walbridge S, Mühlhauser J, Capogrossi MC, Oldfield EH, Merrill MJ.

J Neuropathol Exp Neurol. 1999 Jun;58(6):613-27

Vascular endothelial growth factor (VEGF) is an angiogenic growth factor that also induces vascular permeability and macrophage migration. VEGF expression is weak in normal adult brain, but is strongly upregulated in glioma cells and reactive astrocytes, suggesting that chronic overexpression of VEGF in the brain contributes to blood-brain barrier (BBB) breakdown. We examined the effects of chronic VEGF overexposure on the integrity of the BBB using the following approaches: 1) continuous intracerebral infusion of VEGF via miniosmotic pump; and 2) intracerebral injection of an adenoviral vector encoding the VEGF165 gene (AdCMV.VEGF). After 6 days both treatments produced approximately 10-fold breakdown of the BBB (as measured by transport of 14C-aminoisobutyric acid (AIB) from blood into brain) compared with the respective controls (albumin infusion or AdCMV.beta gal virus). BBB disruption in AdCMV.VEGF-treated brains was accompanied by a severe inflammatory response not observed in brains receiving AdCMV.beta gal or VEGF protein infusion, indicating that neither VEGF nor viral particles alone were responsible for the inflammatory response. However, injection of AdCMV.beta gal followed by VEGF infusion to the same site also elicited inflammation. Chronic overexposure of normal brain to VEGF also increased intercellular adhesion molecule-1 (ICAM-1) and major histocompatibility complex (MHC) class I and II expression. Although VEGF itself is not inflammatory, VEGF may modulate immune responses in the central nervous system (CNS) by opening the BBB, altering the immunoprivileged status of the brain, and allowing contact between normally sequestered CNS antigens and blood-borne immune mediators.

, , ,

Poster un commentaire

Science with coffee :-)

Caffeine blocks disruption of blood brain barrier in a rabbit model of Alzheimer’s disease

Xuesong Chen , Jeremy W. Gawryluk , John F. Wagener , Othman Ghribi and Jonathan D. Geiger

Journal of Neuroinflammation 2008, 5:12doi:10.1186/1742-2094-5-12

High levels of serum cholesterol and disruptions of the blood brain barrier (BBB) have all been implicated as underlying mechanisms in the pathogenesis of Alzheimer’s disease. Results from studies conducted in animals and humans suggest that caffeine might be protective against Alzheimer’s disease but by poorly understood mechanisms. Using rabbits fed a cholesterol-enriched diet, we tested our hypothesis that chronic ingestion of caffeine protects against high cholesterol diet-induced disruptions of the BBB. New Zealand rabbits were fed a 2% cholesterol-enriched diet, and 3 mg caffeine was administered daily in drinking water for 12 weeks. Total cholesterol and caffeine concentrations from blood were measured. Olfactory bulbs (and for some studies hippocampus and cerebral cortex as well) were evaluated for BBB leakage, BBB tight junction protein expression levels, activation of astrocytes, and microglia density using histological, immunostaining and immunoblotting techniques. We found that caffeine blocked high cholesterol diet-induced increases in extravasation of IgG and fibrinogen, increases in leakage of Evan’s blue dye, decreases in levels of the tight junction proteins occludin and ZO-1, increases in astrocytes activation and microglia density where IgG extravasation was present. Chronic ingestion of caffeine protects against high cholesterol diet-induced increases in disruptions of the BBB, and caffeine and drugs similar to caffeine might be useful in the treatment of Alzheimer’s disease.

, , , ,

Poster un commentaire