Effect Of Different Hydration Methods On Prevention Of Contrast Induced Nephropathy And Acetylbritannilactone Attenuates Contrast Induced Acute Kidney Injury Through Anti-pyroptosis Pathway

Contrast induced nephropathy(CIN)is an iatrogenic renal injury that occurs 48-72 hours after contrast agent application,resulted a significant increase in serum creatinine compared with baseline.CIN is a common cause of hospital acquired acute renal failure,which leads to increased mortality,medical expenses and prolonged hospitalization.Once CIN occurs,there was no specific clinical treatment.Therefore,it is very important to explore the pathogenesis and effective prevention measures of CIN.At present,hydration is still the main measure to prevent CIN.Therefore,there is no optimal hydration scheme and consensus.The purpose of this study was to compare the preventive effect of pre-operative and post-operative hydration on CIN in patients with coronary heart disease undergoing elective percutaneous coronary intervention(PCI).To further explore the effect and mechanism of acetylbritannilactone(ABL)attenuates contrast induced acute kidney injury(CI-AKI).Part one Effect of different hydration methods on prevention of contrast induced nephropathy in patients with coronary heart disease undergoing elective PCIAim: To compare the preventive effect of pre-operative and postoperative hydration on CIN in patients with coronary heart disease undergoing elective PCI.Methods: A retrospective study included 198 cases of post-operative and396 cases of pre-operative hydration using propensity score matching.The incidence of CIN 48 hours after PCI and adverse events within 30 days after contrast media exposure were compared between the two groups.Logistic regression analysis was used to analyze the risk factors of CIN.Results: The baseline clinical characteristics between the two groups were similar.The incidence of CIN in post-operative hydration group was3.54%,meanwhile in pre-operative hydration group was 4.8%.There was no significant difference between the two groups(P=0.478).Multivariate logistic regression analysis showed that diabetes mellitus,baseline BNP and cystatin C levels,contrast agent dosage were independent risk factors for CIN.There was no significant difference in the incidence of major adverse events between the two groups(3.03% vs.2.02%,P = 0.830).Conclusions: There was no significant difference between post-operative and pre-operative hydration in the prevention of CIN in patients with coronary heart disease undergoing elective PCI.Part two The role and mechanism of caspase-1 mediated pyroptosis in contrast induced acute kidney injuryObjective: The study aims to investigate the role and mechanism of caspase-1 mediated pyroptosis in contrast induced acute kidney injury(CI-AKI).Methods: Human renal tubular epithelial cells(HK-2)were stimulated with iopromide(IOP).CCK-8 method was used to detect cell survival rate;LDH release was used to evaluate cell death;ELISA was used to detect inflammatory markers IL-1 β and IL-18;Western blot was used to detect pyroptosis related proteins;FLICA/PI double staining flow cytometry was used to detect the pyroptosis death of HK-2 cells.Results: Since the IOP concentration increased(0 20 40 80 160 mg I/m L)and stimulation time prolonged(0 10 30 60 120 min),the cell survival rate was decreased,the LDH release activity and the secretion of IL-1 β and IL-18 were increased.Meanwhile the expression levels of NLRP3 、 ACS 、Mature-GSDMD、Cleaved-caspase-1、IL-1β were also elevated.FLICA/PI flow cytometry result showed that the number of pyroptosis cells was increased gradually.Conclusions: Contrast medium could induce pyroptosis of renal tubular epithelial cells.The pyroptosis pathway mediated by caspase-1 plays an important role in CI-AKI.Part Three Acetylbritannilactone attenuates contrast induced acute kid-ney injury through anti-pyroptosis pathwayObjective: The study aims to investigate the protective effects of acetylbritannilactone(ABL)on contrast induced acute kidney injury(CI-AKI)and reveal the underlying mechanism.Methods: The mice model of acute kidney injury induced by iopromide(IOP)was intervened by ABL.The pyroptosis of HK-2 cells induced by IOP were intervened by ABL in vitro.HE staining was used to observe the pathological changes of kidney tissue.Cell death was assessed by LDH release method.Western blot was used to detect protein levels of NLRP3、ACS、Mature-GSDMD、Cleaved-caspase-1 and IL-1β.Pyroptosis related cytokines IL-1β and IL-18 levels in serum and culture medium were determined by ELISA.Flow cytometry was used to detect the pyroptosis of renal tubular epithelial cells.Results: Compared with IOP-induced acute kindey injury in mice,serum Urea,s Cr and kindey injury score were significant improved after ABL intervention.Meanwhile,the protein levels of NLRP3、ACS、MatureGSDMD、Cleaved-caspase-1 and IL-1β were reduced.In vitro study,ABL intervention could reduce LDH release and down-regulate protein levels of NLRP3、ACS、Mature-GSDMD、Cleaved-caspase-1 and IL-1β.Meanwhile,the results of flow cytometry showed that ABL could alleviate HK-2pyroptosis induced by IOP.Conclusions: ABL may reduce contrast induced acute kidney injury by inhibiting caspase-1 mediated cell pyroptosis.