NOS3 and endothelial dysfunction: The accumulation of uremic toxins (such as indole-3-acetic acid (IAA), hippuric acid and p-cresylsulfate (pCS)) can damage vascular endothelial cells (ECs), leading to endothelial dysfunction manifested by the increase in proinflammatory cytokines and reduction in endothelial nitric oxide synthase (eNOS) [100, 101].