Endothelial Cell Pannexin1 Modulates Severity of Ischemic Stroke by Regulating Cerebral Inflammation and Myogenic Tone

Abstract

Ischemic stroke is a leading cause of morbidity and mortality in the United States; however, there currently exists only one effective acute pharmacological therapeutic intervention. Purinergic signaling has been shown to regulate vascular function and pathological processes, including inflammation and arterial myogenic reactivity, and plays a role in ischemic stroke outcome. Purinergic signaling requires extracellular purines; however, the mechanism of purine release from cells is unclear. Pannexin1 (Panx1) channels are novel purine release channels expressed throughout the vascular tree that couples regulated purine release with purinergic signaling. Therefore, we examined the role of smooth muscle and endothelial cell Panx1 in cerebral ischemia/reperfusion injury outcomes using conditional cell‐type specific transgenic mice. Deletion of endothelial cell Panx1, but not smooth muscle cell Panx1, significantly reduced cerebral infarct volume 24 hrs post‐reperfusion following a 90‐min ischemic injury. Infiltration of leukocytes into brain tissue and development of cerebral myogenic tone were both significantly reduced when mice lacked endothelial Panx1. Interestingly, Panx1 regulation of myogenic tone was unique to the cerebral circulation, as mesenteric myogenic reactivity and blood pressure were independent of endothelial Panx1. Overall, deletion of endothelial Panx1 mitigated cerebral ischemic injury by reducing inflammation and myogenic tone development, indicating that endothelial Panx1 is a possible novel target for therapeutic intervention of ischemic stroke.Support or Funding InformationNIH F32 HL131399, NIH P01 HL120840, NCI P30 CA044579‐23This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.