Indoxyl sulfate, a uremic toxin, downregulates renal expression of Nrf2 through activation of NF-κB

Background Indoxylsulfate, a uremic toxin, is accumulated in the serum of chronic kidneydisease (CKD) patients, accelerating the progression of CKD. In CKD rat kidney, the expressions of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and its related genes are downregulated. AST-120, an oral sorbent, reduces serum indoxylsulfate and slows the progression of CKD. The present study aimed to determine whether indoxylsulfate downregulates Nrf2 expression in human proximal tubular cells and rat kidneysand whether AST-120 upregulates Nrf2 expression in CKD rat kidneys.