Affiliations: Garrison Institute on Aging and Department of Neuropsychiatry and Behavioral Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas, USA
Correspondence:
[*]
Corresponding author: Paula Grammas, PhD, Garrison Institute on Aging, Texas Tech University Health Sciences Center, 3601 4th Street Stop 9424, Lubbock, Texas 79430, USA. Tel.: +1 806 743 3610; Fax: +1 806 743 3636; E-mail: paula.grammas@ttuhsc.edu.
Abstract: The notion that microvascular abnormalities contribute to deleterious changes in the Alzheimer's disease (AD) brain is supported by work from our laboratory and others demonstrating biochemical and functional alterations of the microcirculation in AD. The objective of this study is to determine whether levels of neurotoxic (thrombin) and inflammatory (interleukin 8 (IL-8), integrins αVβ3 and αVβ5) proteins are altered in microvessels isolated from AD patients compared to levels in vessels obtained from non-demented age-matched controls. We also evaluate in AD and control microvessels expression of the transcription factor hypoxia-inducible factor 1-α(HIF1-α), which regulates pro-inflammatory gene expression, and the regulation of HIF1-α expression by thrombin in cultured brain endothelial cells. Our results indicate that in AD there are high levels of expression of the neurotoxic protease thrombin and the inflammation-associated proteins IL-8 and αVβ3 and αVβ5 integrins. HIF1-α is higher in AD microvessels compared to control and thrombin treatment of cultured brain endothelial cells results in increased expression of HIF1-α. These data suggest that in AD the cerebral microcirculation is a source of neurotoxic and inflammatory mediators and as such contributory to pathologic processes ongoing in the AD brain.
