Polydatin Attenuates Cisplatin-induced AKI By Inhibiting Ferroptosis

Background: Nephrotoxic drugs are the common clinical causes of acute kidney injury(AKI).As an effective chemotherapeutic drug,about 21% of the patients treated with cisplatin had complications of AKI,as a chemotherapeutic drug.After the occurrence of AKI,it seriously affected the follow-up treatment and prognosis of patients.At present,there is a lack of effective therapeutic drugs in clinic.It has been found that a new definition of programmed Ferroptosis plays an important role in cisplatin-induced AKI.Ferroptosis inhibitors can reduce cisplatin-induced renal injury.Ferroptosis has been confirmed to play an important role in a variety of AKI models such as AKI caused by rhabdomyolysis,AKI caused by ischemia-reperfusion injury,AKI induced by nephrotoxic drugs such as folic acid and cisplatin.Polydatin is a monomer component from traditional Chinese medicine such as Polygonum cuspidatum,which has many pharmacological activities such as antioxidation and has obvious protective effect on renal IR damage.However,whether it has a protective effect on cisplatin-induced renal injury and whether it has an inhibitory effect on iron death in AKI needs to be further explored.Objective: In this study,we established a cisplatin-induced AKI mouse model and an in vitro cell model to study the role and mechanism of PD in cisplatin-induced ferroptosis in AKI.Methods:1.Animal experiment: male C57BL/6 mice(8-10 weeks,20-25 g)were randomly divided into control group,cisplatin group,PD group and Fer-1 group.Cisplatin group: single intraperitoneal injection of cisplatin(20mg/kg);PD group and Fer-1 group: 2hours after cisplatin injection,intraperitoneal injection of PD(40mg / kg)or Fer-1(5mg /kg),while control group: intraperitoneal injection of the same amount of normal saline containing 5%DMSO.Serum and renal tissue were taken after 48 hours.The renal histopathological score((HSK),)was evaluated by measuring blood urea nitrogen((BUN))and serum creatinine((Scr),).Renal cell apoptosis(TUNEL fluorescence),ROS(DHE fluorescence),iron ion(Prussian blue staining),lipid peroxidation(4HNE and MDA),mitochondrial morphology(transmission electron microscope),GSH and GPX4 levels were analyzed.2.Cell experiment: HK-2 cell viability was determined by CCK-8 and divided into control group,cisplatin / Erastin group,cisplatin / Erastin + PD group(low,middle and high concentration),cisplatin / Erastin + Fer-1 group,cisplatin / Erastin + deferriamine(DFO)group.The indexes related to iron death were divided into cisplatin group,cisplatin + PD group,cisplatin + Fer-1 group and cisplatin + DFO group.ROS(DCFH-DA reactive oxygen probe),iron ion(iron ion kit and Fe Rhonox-1 iron probe),mitochondrial membrane potential(JC-1 staining)and GSH content were measured.Results: 1.Effect of PD on renal function and cell viability: in the animal experiment,compared with the control group,the apoptosis of BUN,Scr,HSK and TUNEL cells in the cisplatin AKI model mice was significantly increased,and the above-mentioned indexes in the PD group were significantly better than those in the cisplatin group(P < 0.01).In the cell experiment,PD improved the survival of HK-2 cells under the condition of cisplatin or Erastin(iron death inducer)in a dose-dependent manner(20,40μM),which was similar to that of Fer-1(inhibitor)and DFO(iron chelator).2.The effect of PD on ROS and iron ion: in both cisplatin AKI animal model and cisplatin HK-2 cell model,PD significantly improved the increase of ROS and iron ion induced by cisplatin.3.Effect of PD on lipid peroxidation: compared with the control group,the levels of MDA and 4HNE in kidney of cisplatin AKI mice were significantly increased,and PD significantly improved the increase of MDA and 4HNE induced by cisplatin(P < 0.01).4.The effect of PD on GSH and GPX4: compared with the control group,cisplatin decreased the level of GSH and GPX4 in the kidney of mice,and PD significantly improved the decrease of GSH and GPX4 induced by cisplatin.5.The effect of PD on the morphology and function of mitochondria: cisplatin significantly induced typical iron death and decreased membrane potential(JC-1)of renal mitochondria;PD significantly improved the morphological and functional abnormalities of mitochondria induced by cisplatin.Conclusion: PD can significantly improve renal function,reduce the production of ROS and iron ions,inhibit lipid peroxidation and abnormal morphology and function of mitochondria in cisplatin AKI mice.The mechanism of improving renal function may be related to the inhibition of ferroptosis in renal tubular epithelial cells.