Role Of NLRP3 In Renal Ischemia Reperfusion Injury And Application Of MCC950

Objective:Ischemia-reperfusion injury is an inflammatory cascade involved in the interaction of multiple factors.It is closely related to delayed graft function and acute rejection after renal transplantation.The mechanism of ischemia-reperfusion injury is not yet clear.Recent studies have found that the NLRP3 inflammasome plays a key role in the inflammatory cascade and plays an important role in ischemia-reperfusion injury.However,related studies mostly focus on organs such as the liver and heart,but there is less research on the kidneys.Therefore,the role of NLRP3 inflammasome in renal ischemia-reperfusion injury requires more research to confirm.Another study found that a novel small molecule compound MCC950 can effectively inhibit cardiac reperfusion injury and various inflammatory diseases by specifically inhibiting the activation of NLRP3.However,there is no research on the effect of MCC950 on renal IRI at home and abroad.Therefore,we hope to investigate the effect of MCC950 in improving renal ischemia-reperfusion injury and the possible mechanism of NLRP3 in renal IRI through this study.Methods:In the first part,8-10 week-old male C57BL/6 mice were used,and the body weight was 20-25 g.The renal ischemia-reperfusion injury model was established by clamping bilateral renal pedicles.Blood samples and Bilateral renal tissue specimens were obtained at different time points after reperfusion,serum SCr,BUN reflect renal function changes,renal pathological section stained to observe the extent of kidney damage,Western Blot detect the expression of NLRP3 protein.In the second part,we use 8-10 weeks old male C57BL/6 mice,weighing 23-28 g.They were pretreated by tail vein injection of NLRP3 specific inhibitor MCC950.Then the renal ischemia-reperfusion injury model was established,Blood samples and bilateral kidneys were obtained 24 hours after reperfusion.Serum Cr and BUN levels were measured to reflect changes in renal function.Kidney pathological sections were used to observe the degree of renal damage.Western Blot was used to detect the expression of NLRP3 protein and caspase-1 protein.ELISA was used to detect the expression of IL-1? in kidney tissue.Results:1.Kidney pathological staining showed that there were different degrees of kidney injury at 1h,6h,12 h,24h,and 48 h after ischemia/reperfusion in mice.The most serious damage occurs in 24 hours after reperfusion,the structure of the renal tubules disappears,and some show necrosis in slices or foci in varying degrees.Tube formation is seen in the lumen.2.After reperfusion,serum Cr and BUN were significantly elevated and peaked at 24 hours.3.By Western Blot analysis,we found that NLRP3 expression was significantly increased after reperfusion and reached a peak at 12 hours.4.Compared with the 24 h group after reperfusion,the degree of renal tissue damage was significantly reduced in the MCC950 intervention group,renal function was improved,and the expression of caspase-1 and IL-1? was decreased.Conclusion:1.After renal ischemia-reperfusion,the expression of NLRP3 was significantly increased.After inhibiting the expression of NLRP3 by MCC950,renal function and renal pathological injury were significantly improved,demonstrating that NLRP3 plays an important role in renal ischemia-reperfusion injury.2.MCC950 can effectively inhibit the expression of NLRP3 protein,significantly reduce the renal damage caused by reperfusion,indicating that MCC950 is expected to become a targeted drug for the treatment of renal ischemia-reperfusion injury.3.After reperfusion,the expression of caspase-1 and IL-1? in NLRP3 protein was increased.After NLRP3 was inhibited,the expression of caspase-1 and IL-1? was decreased,suggesting that NLRP3 might works through NLRP3/caspase-1/IL-1? pathway.