Angiopoietin-2 Levels increase following Oxygen Glucose Deprivation (OGD) and Reperfusion in Brain Microvascular Endothelial Cells

Abstract

Stroke is a leading cause of death, as onset induces an innate immune response using Toll-like receptor 4 (TLR4), which promotes inflammation and blood-brain barrier (BBB) permeability. TLR4 is a receptor for high-mobility group box 1 (HMGB1), a non-histone protein involved in inflammation and secreted by endothelial cells (ECs) in the BBB. Angiopoietin-2 is another inflammatory protein known to increase BBB permeability. The role of Angiopoietin-2 in EC activation following cerebral ischemia is not known. Therefore, this study used oxygen glucose deprivation (OGD) to stimulate in vitro ischemia to assess Angiopoietin-2 in rat brain microvascular ECs. We found that Angiopoietin-2 levels increase after 20 hour OGD, but not statistically significant. Angiopoietin-2 levels return to baseline after 20 hour OGD with reperfusion. Thus, Angiopoietin-2 may play an important role in BBB permeability following focal cerebral ischemia. Therapies directed at modulating Angiopoietin-2, following cerebral ischemia, may be important in treating ischemia stroke.