ZIP14 is involved in iron deposition and triggers ferroptosis in diabetic nephropathy.

Ferroptosis is caused by lipid peroxidation and iron accumulation and can cause cell death. Abnormally expressed iron transporters are involved in ferroptosis in a variety of diseases. ZRT/IRT-like protein 14 (ZIP14) is a transport protein that can mediate cellular uptake of iron, zinc, and manganese. Herein, we have tested the hypothesis that the divalent metal transporter ZIP14 is involved in the initiation of ferroptosis in diabetic nephropathy (DN). DN was induced in 8-week-old male rats by streptozotocin before analysis of the degree of renal tubular injury. In addition, an in vitro model of DN in human kidney proximal tubular cell line was used. We showed that ZIP14 was up-regulated and ferrous iron (Fe2+) levels increased both in vivo and in vitro. Expression of glutathione peroxidase 4 and the level of glutathione were reduced, whereas that of malondialdehyde (MDA) increased. Ferrostatin-1 (Fer-1) treatment reduced the expression of ZIP14 and the levels of Fe2+ and MDA, which is consistent with ferroptosis. Fer-1 improved kidney function in DN rats. This was characterized by urine levels of protein-to-creatinine ratio, α1-microglobulin, and N-acetyl-β-D-glucosaminidase. Our study demonstrates a novel role for ZIP14 in diabetic kidney injury mediated by ferroptosis, and suggests a potential new therapeutic approach for the treatment of diabetic nephropathy.