Proteome profiling of brain vessels in a mouse model of cerebrovascular pathology

Abstract

A cerebrovascular pathology that involves altered protein levels or signaling of the transforming growth factor beta (TGFβ) family has been associated with various forms of dementia, including Alzheimer disease (AD) and vascular cognitive impairment and dementia (VCID). Transgenic mice overexpressing TGFβ1 in the brain (TGF mice) recap VCID-associated cerebrovascular pathology and develop cognitive deficits in old age or when submitted to comorbid cardiovascular risk-factors for dementia. Here, we characterized the cerebrovascular proteome of TGF mice using mass-spectrometry (MS) based quantitative proteomics. Cerebral arteries were surgically removed from 6-month-old-TGF and wild-type mice, proteins extracted and analyzed by gel-free nanoLC-MS/MS. We identified 3,602 proteins in brain vessels, with 20 demonstrating robust altered levels in TGF mice. For total and/or differentially-expressed proteins (p≤0.01, ≥2-fold change), using multiple databases, we performed protein characterization, and identified proteins demonstrating RNA-transcripts in both mouse and human cerebrovascular cells, and known to be present in human-extracellular-vesicles (EVs). Dysregulated proteins point to perturbed brain vessel vasomotricity, remodeling, and inflammation. Given that blood-isolated EVs are novel, attractive and a minimally invasive biomarker discovery platform for the age-related dementias, several proteins identified in this study can potentially serve as VCID markers in humans.