Effect Of Ozone Pretreatment On The Pyroptosis Of Renal Tubular Epithelial Cells In Mice With Acute Kidney Injury In Sepsis

Objective Acute Kidney Injury(AKI)due to sepsis is a common critical clinical condition with high mortality rate,the mechanism of which is not fully understood and seriously threatens patients’ life safety.Pyroptosis,a programmed cell death mode,is an important cause of AKI due to the inflammatory response triggered by its over-activation.Therefore,this study was conducted to investigate the protective effect of ozone pretreatment on septic AKI by inhibiting cellular pyroptosis in a mouse model of sepsis induced by lipopolysaccharide(LPS)after ozone pretreatment.We hope to provide a new target and theoretical basis for the treatment of septic AKI-induced inflammatory response.Method SPF grade male C57BL/6 mice,6～8 weeks old,22±2g,were divided into 4 groups(n=8)according to the random scale method: blank control group(Control group),ozone+lipopolysaccharide group(Ozone+LPS group),air+lipopolysaccharide group(Air+LPS group),and lipopolysaccharide group(LPS group).ozone+LPS group was injected intraperitoneally once a day LPS group,Air+LPS group and Ozone+LPS group were injected intraperitoneally with LPS 10mg/kg 24 h after the last pretreatment,and the Control group was injected with saline 10mg/kg.6h after modeling,kidney specimens were taken from mice.HE staining was used to observe the kidney injury;flow cytometry was used to detect the pyroptosis of mouse renal tubular epithelial cells;Western blotting was used to detect the expression changes of cysteine asparticase-11(Caspase-11)and Gasdermin D(GSDMD)in mouse renal tubular epithelial cells.Blood creatinine(Scr)and urea nitrogen(BUN)were measured using a fully automated biochemical analyzer.The expression of the inflammatory factors interleukin-1β(IL-1β)and interleukin-18(IL-18)in mouse serum was measured using ELISA.interleukins 18,IL-18)expression levels in mice.Results(1)HE staining results showed that the kidney histomorphology was basically normal in the Control group,and the renal tubular epithelial cells in the LPS and Air+LPS groups were detached and swollen,and the renal tubules were seen to be significantly congested and infiltrated with inflammatory cells.the above symptoms were significantly reduced in the Ozone+LPS group compared with the LPS group;(2)Compared with the Control group,the LPS group,Air+LPS group and Ozone+LPS group had higher SCr and BUN levels compared with the Control group(P<0.05).Compared with the LPS group,the results of mice in the Air+LPS group were not statistically significant(P>0.05),and the levels of SCr and BUN in the Ozone+LPS group were significantly decreased(P<0.05);(3)Compared with the Control group,the rate of renal tubular epithelial cell pyroptosis was increased in the LPS,Air+LPS and Ozone+LPS groups(P<0.05).Compared with the LPS group,the level of pyroptosis in mouse renal tubular epithelial cells in the Air+LPS group was not statistically significant(P>0.05),and the level of pyroptosis in mouse renal tubular epithelial cells in the Ozone+LPS group was significantly decreased(P<0.05);(4)Compared with the Control group,the level of pyroptosis in renal tubular epithelial cells in the LPS,Air+LPS and Ozone+LPS groups related protein Caspase-11 and GSDMD expression levels were increased(P<0.05).After pretreatment with ozone,the expression levels of Caspase-11 and GSDMD in renal tubular epithelial cells in the Air+LPS group were not statistically significant compared with the LPS group(P>0.05),and the expression levels of Caspase-11 and GSDMD in renal tubular epithelial cells in the Ozone+LPS group were decreased(P<0.05);(5)Compared with the Control group,the expression of inflammatory factors IL-1β and IL-18 in serum was increased in the LPS group,Air+LPS group and Ozone+LPS group(P<0.05);compared with the LPS group,the levels of inflammatory factors in serum were not statistically significant in the Air+LPS group(P>0.05),and the expression levels of IL-1β and IL-18 in serum were significantly decreased in the Ozone+LPS group(P<0.05).Conclusion Ozone pretreatment can play a protective role against septic AKI by inhibiting renal tubular epithelial cell pyroptosis,improving septic AKI,and reducing the inflammatory response.