Astrocytes express the glucagon-like peptide-1 receptor (GLP-1R), and activation of GLP-1R not only protects the BBB and reduces ischemia-induced neuroinflammation but also reduces the release of vascular endothelial growth factor A, matrix metalloproteinase 9 (MMP9), monocyte chemotactic protein-1 and chemokine ligand 1 (C-X-C motif). The gene discussed is MMP9; the disease is ischemia.