Inhibition of α5β1integrin with the clinically validated small peptide, ATN‐161 stabilizes cerebral vasculature, reduces inflammation, and decreases blood‐brain barrier permeability after experimental ischemic stroke

Abstract

Stroke is the second leading cause of death and the leading cause of long‐term disability worldwide. Blood‐brain barrier (BBB) dysfunction exacerbates reperfusion‐induced injury after recanalization in ischemic stroke. Endothelial cell integrin receptors, specifically the β1 subtype, play a direct role in this BBB dysfunction through regulation of barrier‐forming tight junction (TJ) proteins. We hypothesize that inhibition of a specific β1 integrin subtype, α5β1, will stabilize the BBB, and thereby reduce infarct volumes and improve functional recovery after experimental stroke.MethodMale C57BLJ6 mice underwent transient middle cerebral artery occlusion for 1 hour. Upon reperfusion, vehicle or the clinically validated α5β1 inhibitor, ATN‐161 (1mg/kg), was injected intraperitoneally and repeated 24 and 48 hours later. Infarct volume (TTC and MRI – DTI sequence) and edema volume (T2‐weighted MRI) was determined on PSD3. Functional recovery was determined by an 11‐point Neuroscore on PSD1‐PSD7. Physiological measurements, including pulse distention, heart rate and body temperature, were obtained before, during and after the initial dose of ATN‐161. Immunohistochemical analysis of α5β1, claudin‐5, CD45 (pan‐leukocyte), and IgG, expression was performed on PSD3. qPCR analysis on claudin‐5, collagen IV, MMP‐9, IL‐1β, and CXCL12 were performed on PSD3.ResultsATN‐161 administration reduced infarct volume, edema volume, and functional deficit. ATN‐161 also resulted in cerebral vascular stabilization by a decrease in MMP‐9 and increases in claudin‐5, and collagen IV. Furthermore, IL‐1β and CD45 was reducedupon ATN‐161 administration, suggesting a decrease in the post‐stroke inflammatory response. Together, the cerebrovascular stabilization and decrease in inflammation resulted in less IgG extraversion, suggesting a more intact BBB. Collectively, administration of ATN‐161 post‐stroke produced significant benefits, and thus could represent a novel stroke therapy worthy of further investigation.Support or Funding InformationThis work was supported by NIH R01NS065842.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.