IL-1alpha induces angiogenesis in brain endothelial cells in vitro: implications for brain angiogenesis after acute injury

摘要

Inflammation is a major contributor to neuronal injury and is associated with poor outcome after acute brain injury such as stroke. The pro-inflammatory cytokine interleukin (IL)-1 is a critical regulator of cerebrovascular inflammation after ischemic injury, mainly through action of both of its isoforms, IL-1α and IL-1β, at the brain endothelium. In contrast, the differential action of these ligands on endothelial activation and post-stroke angiogenesis is largely unknown. Here, we demonstrate that IL-1α is chronically elevated in the brain after experimental stroke suggesting that it is present during post-stroke angiogenic periods. Furthermore, we demonstrate that IL-1α is a potent mediator of endothelial activation and inducer of angiogenic markers in endothelial cells in vitro. Using brain endothelial cell lines, we found that IL-1α was significantly more potent than IL-1β at inducing endothelial cell activation, as measured by expression of the pro-angiogenic chemokine CXCL-1. IL-1α also induced strong expression of the angiogenic mediator IL-6 in a concentration-dependent manner