PPARA and type 2 diabetes mellitus: In summary, M1 macrophage recruitment due to the upregulated HIF-1α/Notch1 pathway induced by endothelial cell dysfunction involves in type 2 diabetic mouse renal injury, and PPAR-α agonist fenofibrate prevents DN by reducing M1 macrophage recruitment through inhibiting HIF-1α/Notch1 pathway caused by the improved endothelial cell function in type 2 diabetic mouse kidneys.