Hyperglycemia-induced upregulation of many cytokines, chemokines, and enzymes, such as angiopoietins, interleukins (ILs), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and matric metalloproteinases (MMPs), play a synergic role leading to the breakdown of BRB [41,45]. Here, NOS2 is linked to Hyperglycemia.