Faculty, Staff and Student Publications

Language

English

Publication Date

8-1-2025

Journal

Translational Stroke Research

DOI

10.1007/s12975-024-01295-0

PMID

39294532

PMCID

PMC12202595

PubMedCentral® Posted Date

9-19-2024

PubMedCentral® Full Text Version

Post-print

Abstract

Impaired cerebral circulation, induced by blood vessel constrictions and microthrombi, leads to delayed cerebral ischemia after subarachnoid hemorrhage (SAH). 12/15-Lipooxygenase (12/15-LOX) overexpression has been implicated in worsening early brain injury outcomes following SAH. However, it is unknown if 12/15-LOX is important in delayed pathophysiological events after SAH. Since 12/15-LOX produces metabolites that induce inflammation and vasoconstriction, we hypothesized that 12/15-LOX leads to microvessel constriction and microthrombi formation after SAH, and thus, 12/15-LOX is an important target to prevent delayed cerebral ischemia. SAH was induced in C57BL/6 and 12/15-LOX−/− mice of both sexes by endovascular perforation. Expression of 12/15-LOX was assessed in brain tissue slices and in vitro. C57BL/6 mice were administered either ML351 (12/15-LOX inhibitor) or vehicle. Mice were evaluated for daily neuroscore and euthanized on day 5 to assess cerebral 12/15-LOX expression, vessel constrictions, platelet activation, microthrombi, neurodegeneration, infarction, cortical perfusion, and development of delayed deficits. Finally, the effect of 12/15-LOX inhibition on platelet activation was assessed in SAH patient samples using a platelet spreading assay. In SAH mice, 12/15-LOX was upregulated in brain vascular cells, and there was an increase in 12-S-HETE. Inhibition of 12/15-LOX improved brain perfusion on days 4–5 and attenuated delayed pathophysiological events, including microvessel constrictions, microthrombi, neuronal degeneration, and infarction. Additionally, 12/15-LOX inhibition reduced platelet activation in human and mouse blood samples. Cerebrovascular 12/15-LOX overexpression plays a major role in brain dysfunction after SAH by triggering microvessel constrictions and microthrombi formation, which reduces brain perfusion. Inhibiting 12/15-LOX may be a therapeutic target to improve outcomes after SAH.

Keywords

Animals, Subarachnoid Hemorrhage, Arachidonate 12-Lipoxygenase, Mice, Inbred C57BL, Male, Mice, Female, Arachidonate 15-Lipoxygenase, Microvessels, Mice, Knockout, Disease Models, Animal, Intracranial Thrombosis, Subarachnoid hemorrhage, Delayed neurological deficit, Platelets, 12/15-Lipooxygenase, Microvessel constrictions, Microthrombi, Arterioles

Published Open-Access

yes

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