Effect Of Electro-acupuncture On Keapl-Nrf2/ARE Pathway During Endotoxin-induced Acute Kidney Injury In Rabbits

Endotoxaemia is a common clinical complications of severe trauma, infection, but also acute kidney injury and multiple organ dysfunction syndrome common factors. Endotoxin-induced acute kidney injury (AKI) is considered to be an independent risk factor for the development and prognosis of predicting the condition of critically ill patients. Numerous studies have shown that electro-acupuncture (EA) has a protective effect on renal function, but the exact mechanism is still unclear.Objective:This study intends to electroacupuncture Zusanli and Shenshu Point to explore the relationship between the protective effect of Electroacupuncture on endotoxin induced acute renal injury and Keap1-Nrf2/ARE.Methods:Clean healthy adult male New Zealand white rabbits, weighing1.5-2.Okg, were randomly divided into4groups randomly (n=10):group control (group C); group endotoxin-induced acute kidney injury (AKI)(group AKI); group electro-acupuncture (EA)+endotoxin-induced AKI (group EA); group sham EA+endotoxin-induced AKI (group SEA). The animals were anesthetized with intraperitoneal injection20%urethane (1.5g/kg). kept spontaneous respiration. Right internal carotid artery was cannulated for BP monitoring. Ear vein injection of LPS5mg/kg to establish model of endotoxin-induced AKI. It was confirmed by blood pressure dropped at least to75%of the baseline value. Group EA stimulation parameters:density wave, frequency of15Hz, the intensity of stimulation of rabbit muscle fasciculation is slight degree,5days before the experiment acupuncture Zusanli and Shenshu1times each day, lasting10min, needle retaining1h; The experiment of acupuncture from the model building last to the end of the experiment. SEA group selection in acupuncture group by0.5cm parts, Stimulation parameters and time, at6h after LPS injection,5ml blood samples were obtained from the carotid artery,2ml urine from the ladder. the concentration of serum nitrogen (BUN), creatinine (Cr), urine a1-MG were detected by automatic biochemistry analyzer. Tumor necrosis factor alpha (TNF-α) and interleukin10(IL-10) were measured by enzyme-linked immunosorbent assay (ELISA). The rabbits were then sacrificed and then kidneys were isolated. The left kidney and fixed with paraformaldehyde, using hematoxylin and eosin(HE) staining to observe the renal pathological changes and score (HSK), The rate of water content (WCR) of kidney was determined. The right kidney rapidly into the freezing tube liquid nitrogen frozen, stored at-80℃. Prepare renal tissue homogenate, the activity of superoxide dismutase (SOD) were measured by the method of xanthine oxidase, the contents of serum malondialdehyde(MDA) wer determined by the method of thiobarbituric acid. Western bloting was used to detect the expression of Nrf2total protein and nuclear protein, HO-1protein, reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expression of Nrf2mRNA, HO-1mRNA.Results:Compared with group C, serum levels of BUN, Cr, TNF-a, IL-10, urine a1-MG, HSK, WCR, the contents of MDA, Nrf2total protein and nuclear protein, HO-1protein expression and the gene expression of Nrf2mRNA and HO-1mRNA were significantly increased, the activity of SOD was significantly decreased in group AKI, EA and SEA(P <0.05). Compared with group AKI, serum levels of BUN, Cr, TNF-a, urine α1-MG, HSK, WCR, and the contents of MDA were significantly decreased, serum levels of IL-10, the activity of SOD, Nrf2total protein and nuclear protein, HO-1protein expression and the gene expression of Nrf2mRNA and HO-1mRNA were significantly increased in group EA(P<0.05). Compared with group EA, serum levels of BUN, Cr, TNF-a, urine a1-MG, HSK, WCR, and the contents of MDA were significantly increased, serum levels of IL-10, the activity of SOD, Nrf2total protein and nuclear protein, HO-1protein expression and the gene expression of Nrf2mRNA and HO-1mRNA were significantly decreased in group SEA (P<0.05).Conclusions:In summary, electro-acupuncture at Zusanli and Shenshu can attenuate AKI induced by endotoxin in rabbits, and its mechanism may be related with the activation of keap1-Nrf2/ARE pathway, with upregulating HO-1expression in the kidney.