Abstract T P241: Deletion of PGE2 EP1 Receptor Results in Reduced Phagocytosis and Exacerbates Hemorrhagic Injury

Background: Spontaneous intracerebral hemorrhage (ICH) is the deadliest and most debilitating form of stroke with a first year mortality rate as high as 50% to 60%. Role of prostaglandin E2 (PGE2) receptor EP1 has been extensively studies in ischemic stroke; however, the precise role of this receptor in intracerebral hemorrhage-induced brain injury is unknown. Therefore, in this study we determined the role of the EP1 receptor in collagenase-induced hemorrhagic stroke. Methods: ICH was induced randomly in 2.0-2.5 month old male C57BL/6 wildtype (WT) and EP1 knockout (EP1-/-) mice by intrastriatal injection of collagenase. Functional outcomes including neurologic deficits, rotarod performance, open field activity, and adhesive removal performance were evaluated at 72h post ICH. Hematoma volume, and cell survival and death, were assessed using cresyl violet and Fluoro-Jade staining respectively. Microglial activation was estimated using Iba1 immunoreactivity. Phagocytosis was assessed with fluorescently-lab...