title: Prostaglandin E2 EP2 receptor deletion attenuates intracerebral hemorrhage-induced brain injury and improves functional recovery.
abstract: Intracerebral hemorrhage (ICH) is a devastating type of stroke characterized by bleeding into the brain parenchyma and secondary brain injury resulting from strong neuroinflammatory responses to blood components. Production of prostaglandin E2 (PGE2) is significantly upregulated following ICH and contributes to this inflammatory response in part through its E prostanoid receptor subtype 2 (EP2). Signaling through the EP2 receptor has been shown to affect outcomes of many acute and chronic neurological disorders; although, not yet explored in the context of ICH. Wildtype (WT) and EP2 receptor knockout (EP2(-/-)) mice were subjected to ICH, and various anatomical and functional outcomes were assessed by histology and neurobehavioral testing, respectively. When compared with age-matched WT controls, EP2(-/-) mice had 41.9 ± 4.7% smaller ICH-induced brain lesions and displayed significantly less ipsilateral hemispheric enlargement and incidence of intraventricular hemorrhage. Anatomical outcomes correlated with improved functional recovery as identified by neurological deficit scoring. Histological staining was performed to begin investigating the mechanisms involved in EP2-mediated neurotoxicity after ICH. EP2(-/-) mice exhibited 45.5 ± 5.8% and 41.4 ± 8.1% less blood and ferric iron accumulation, respectively. Furthermore, significantly less striatal and cortical microgliosis, striatal and cortical astrogliosis, blood-brain barrier breakdown, and peripheral neutrophil infiltration were seen in EP2(-/-) mice. This study is the first to suggest a deleterious role for the PGE2-EP2 signaling axis in modulating brain injury, inflammation, and functional recovery following ICH. Targeting the EP2 G protein-coupled receptor may represent a new therapeutic avenue for the treatment of hemorrhagic stroke.
authors: Department of Anesthesiology, University of Florida, Gainesville, FL, USA Department of Neuroscience, University of Florida, Gainesville, FL, USA.
authors: Jenna L
authors: JL
authors: Leclerc
authors: Department of Anesthesiology, University of Florida, Gainesville, FL, USA.
authors: Andrew S
authors: AS
authors: Lampert
authors: Department of Anesthesiology, University of Florida, Gainesville, FL, USA.
authors: Matthew A
authors: MA
authors: Diller
authors: Department of Anesthesiology, University of Florida, Gainesville, FL, USA.
authors: Joshua B
authors: JB
authors: Immergluck
authors: Department of Anesthesiology, University of Florida, Gainesville, FL, USA Department of Neuroscience, University of Florida, Gainesville, FL, USA Departments of Neurology, Psychiatry, and Pharmaceutics, University of Florida, Gainesville, FL, USA sdore@ufl.edu.
authors: Sylvain
authors: S
authors: Doré
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000473:pathology / Q000502:physiology; D001812:Blood-Brain Barrier / Q000473:pathology / Q000503:physiopathology; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D002543:Cerebral Hemorrhage / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D004195:Disease Models, Animal; D005911:Gliosis / Q000473:pathology / Q000503:physiopathology; D007501:Iron / Q000378:metabolism; D008297:Male; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D017628:Microglia / Q000473:pathology / Q000502:physiology; D015213:Neuroimmunomodulation / Q000502:physiology; D020556:Neutrophil Infiltration / Q000502:physiology; D058307:Receptors, Prostaglandin E, EP2 Subtype / Q000172:deficiency* / Q000235:genetics; D020127:Recovery of Function / Q000502:physiology
chemical_list: D058307:Receptors, Prostaglandin E, EP2 Subtype; D007501:Iron
keywords: collagenase; gliosis; iron; neuroinflammation; neuroprotection; stroke