4辛基-衣康酸通过Nrf2/ARE通路抑制氧化应激减轻高脂饮食诱导的早期肾损伤

Effect of 4-octyl itaconate in attenuating early renal injury induced by high-fat diet through inhibiting oxidative stress via the nuclear factor erythroid 2-related factor 2/antioxidant response element pathway

摘要

目的 研究4辛基-衣康酸（4-octyl itaconate，4-OI）通过核因子E2相关因子2（nuclear factor-erythroid 2-related factor 2，Nrf2）/抗氧化反应元件（antioxidant response element，ARE）通路减轻高脂饮食（high fat diet，HFD）诱导的早期肾脏损伤的效应及机制。 方法 将小鼠随机分为对照组、HFD组、4-OI组3组；HFD组和4-OI组接受HFD喂养12周，4-OI组自HFD喂养第9周起接受4-OI干预。检测糖耐量及尿白蛋白肌酐比值（urinary albumin/creatinine ratio，UACR）；苏木精伊红（hematoxylin-eosin，HE）染色和高碘酸-希夫（periodic acid-Schiff，PAS）染色观察肾皮质病理变化；酶联免疫吸附测定法（enzyme-linked immune sorbent assay，ELISA）检测血脂和肾皮质氧化应激相关指标；检测肾小管损伤标志物及肾皮质Nrf2/ARE通路相关分子的表达水平。 结果 4-OI干预可减轻高脂饮食导致的肾近曲小管刷状缘断裂和上皮细胞脱落，降低肾皮质肾小管损伤标志物肾损伤分子1（kidney injury molecule 1，KIM-1）、中性粒细胞明胶酶相关脂质运载蛋白（neutrophil gelatinase-associated lipocalin protein，NGAL）表达和尿液上清液中的UACR含量（P=0.001、P=0.002、P=0.000），减轻肾皮质氧化应激，如还原型谷胱甘肽（glutathione，GSH）、超氧化物歧化酶（superoxide dismutase，SOD）的回升和丙二醛（malondialdehyde，MDA）的回降（P=0.040、P=0.000、P=0.001），增加Nrf2以及Nrf2/ARE通路相关分子血红素加氧酶-1（heme oxygenase 1，HO-1）、NAD（P）H脱氢酶（醌）1（NAD（P）H dehydrogenase［quinone］1，NQO1）、超氧化物歧化酶1（superoxide dismutase 1，SOD1）蛋白表达水平（P=0.003、P=0.000、P=0.001、P=0.000）和mRNA表达水平（P=0.000、P=0.009、P=0.000、P=0.000）。 结论 4-OI可能通过激活Nrf2/ARE通路降低肾脏氧化应激水平，从而改善HFD导致的早期肾损伤。

Abstract

Objective To investigate the effect and mechanism of 4-octyl itaconate（4-OI） in alleviating early renal injury induced by high-fat diet（HFD） via the nuclear factor erythroid 2-related factor 2（Nrf2）/antioxidant response element（ARE） pathway. Methods Mice were randomly divided into control group，HFD group，and 4-OI group. The mice in the HFD group and the 4-OI group were given HFD feeding for 12 weeks，and those in the 4-OI group were given 4-OI intervention since week 9 of HFD feeding. Glucose tolerance and urinary albumin-to-creatinine ratio（UACR） were measured；HE staining and periodic acid-Schiff staining were used to observe the pathological changes of renal cortex；ELISA was used to measure blood lipids and renal cortical oxidative stress-related indicators；the expression levels of renal tubular injury markers and the molecules involved in the Nrf2/ARE pathway in renal cortex were measured. Results This study showed that 4-OI intervention significantly alleviated the brush border fracture and epithelial cell shedding of renal proximal convoluted tubules and reduced the expression levels of the renal tubular injury markers kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin in renal cortex and the content of UACR in urine supernatant（P=0.001，0.002，and 0.000），and it also reduced renal cortical oxidative stress，including the increases in glutathione and superoxide dismutase（SOD） and the reduction in malondialdehyde（P=0.040，0.000，and 0.001）. 4-OI intervention increased the protein and mRNA expression levels of Nrf2 and the Nrf2/ARE pathway-related molecules heme oxygenase-1，NAD（P）H dehydrogenase［quinone］1，and superoxide dismutase 1（protein expression：P=0.003，0.000，0.001，and 0.000； mRNA expression：P=0.000，0.009，0.000，and 0.000）. Conclusion 4-OI may reduce the level of renal oxidative stress by activating the Nrf2/ARE pathway，thereby improving early renal injury caused by HFD.

关键词

肾损伤 / 肾小管 / 高脂饮食 / 4辛基-衣康酸 / 氧化应激

Key words

kidney injury / renal tubule / high-fat diet / 4 octyl-itaconic acid / oxidative stress

基金资助

重庆医科大学未来医学青年创新团队资助项目(W0085)