银杏叶提取物缓释剂穴位埋药线对局灶性脑缺血再灌注大鼠脑组织损伤及Nrf2/HO-1信号通路的影响

银杏叶提取物缓释剂穴位埋药线对局灶性脑缺血再灌注损伤大鼠脑组织损伤及其对Nrf2/HO-1信号通路的影响。采用改良线栓法制备脑缺血再灌注大鼠模型,银杏叶提取物缓释剂穴位埋药线后进行神经缺失症状评分,测定神经细胞病理学,检测丙二醛(MDA)、一氧化氮(NO)、超氧化物歧化酶(SOD)和谷胱甘肽(GSH)及脑组织Nrf2和HO-1 mRNA和蛋白的表达。结果表明银杏叶提取物缓释剂穴位埋药线可显著改善脑缺血再灌注模型动物的神经功能,提高神经细胞存活率,显著降低MDA、NO含量,升高总SOD活性和GSH含量,调节Nrf2/HO-1 mRNA和蛋白的表达水平。银杏叶提取物缓释剂穴位埋药线具有抗脑缺血再灌注损伤作用,其机制可能与与激活Nrf2/HO-1途径,促进了Nrf2的核转位,使HO-1等抗氧化物质表达上调,提高了机体对氧化损伤的抗性有关。     

氧化应激对肝星状细胞转录因子Nrf2核转位的影响

目的:研究细胞转录因子NF-E2相关因子2(nuclear factor-erythroid 2 related factor 2,Nrf2)在大鼠肝星状细胞系HSC-T6中的表达及氧化应激对其核转位的影响.方法:将大鼠肝星状细胞(HSC-T6)分成空白对照组和氧化应激组,氧化应激组加入100mU/ml葡萄糖氧化酶(glucose oxidase,GO)干预2h制备细胞氧化应激模型,空白对照组予以DMEM正常培养未进行GO干预.Western blot方法检测Nrf2总蛋白及核蛋白的变化,细胞免疫化学法观察HSC-T6细胞Nrf2核转位情况,流式细胞术检测细胞内活性氧(reactive oxygen species,ROS)水平的变化,分光光度法检测细胞丙二醛(malondialdehyde,MDA)、谷胱甘肽(glutathione,GSH)水平.结果:1氧化应激组ROS及MDA水平较空白对照组显著升高(P<0.01).2 WB显示Nrf2总蛋白在两组的表达无显著差异,而Nrf2核蛋白在空白对照组中无明显表达,在氧化应激组表达明显增加;ICC显示空白对照组中Nrf2蛋白仅在胞浆中表达;而氧化应激组胞核和胞浆中均可见Nrf2蛋白表达.3氧化应激组GSH水平较空白对照组显著升高(P<0.01).结论:在氧化应激过程中Nrf2发生核转位从而发挥其生物学功能.     

葡萄籽原花青素通过Nrf2/ARE信号通路抗高糖诱导的HUVEC-12细胞氧化损伤

研究葡萄籽原花青素提取物(GSPE)对高糖诱导的人脐静脉内皮细胞HUVEC-12氧化应激损伤的保护作用及其相关机制。建立高糖诱导的HUVEC-12细胞模型,测定细胞活力,检测细胞内活性氧(ROS)水平、乳酸脱氢酶(LDH)与超氧化物歧化酶(SOD)活性及Nrf2/ARE信号通路中相关基因mRNA水平和蛋白含量。结果显示GSPE作用后显著提高HUVEC-12细胞活力,抑制高糖诱导的细胞内ROS水平升高,增强SOD活性(P0.05),并呈现剂量依赖效应。GSPE作用能同时提高抗氧化转录因子Nrf2和下游区GSH-Px、HO-1、γ-GCS、NQO1基因的表达量以及HO-1、NQO1蛋白的含量(P0.05)。结果表明GSPE能通过激活Nrf2/ARE通路对抗高糖诱导的HUVEC-12细胞氧化应激损伤。     

丹参酚酸B通过Nrf2/HO-1对脑缺血/再灌注损伤的保护作用研究

目的:研究丹参酚酸B对脑缺血/再灌注(Cerebral ischemia/reperfusion,CI/R)损伤的保护作用及机制。方法:通过结扎颈总动脉缺血2 h再灌注48 h复制CI/R模型,将实验大鼠随机分为假手术组、模型组、丹参酚酸B组,每组10只,培养大脑皮层神经细胞,分别给予0,10,25,50 umol/L的丹参酚酸B。通过2,3,5-氯化三苯基四氮唑蓝(TTC)染法测定大鼠脑梗死面积,Western Blot检测大鼠Nrf2和HO-1蛋白表达水平以及细胞中Nrf2和HO-1蛋白表达水平。再通过细胞缺氧缺糖模型,检测不同浓度丹参酚酸B对于细胞死亡率及细胞内ROS水平以及转染Nrf2或HO-1 si RNA后细胞死亡率及细胞内ROS水平。结果:与模型组比较,丹参酚酸B组的大鼠脑梗死面积明显减小,脑组织中Nrf2和HO-1蛋白表达水平均明显增加(P0.05)。大脑皮层细胞中,随着丹参酚酸B浓度增加,细胞HO-1蛋白及细胞核中Nrf2蛋白表达水平逐渐提高,而细胞质中Nrf2蛋白表达水平逐渐降低(P0.05)。细胞缺糖缺氧条件下,与对照组相比,丹参酚酸B组均能够降低细胞的死亡率及细胞内ROS水平,敲除Nrf2或HO-1后,丹参酚酸B组的细胞死亡率与细胞内ROS水平均有明显减低(P0.05)。结论:丹参酚酸B对大鼠CI/R具有保护作用,其作用机制可能通过Nrf2/HO-1减轻CI/R所造成的氧化应激损伤。     

银杏叶提取物对对乙酰氨基酚诱导的小鼠急性肝损伤的保护作用

目的：探究银杏叶提取物（GBE）对对乙酰氨基酚（APAP）诱导的小鼠急性肝损伤的保护作用及其机制。方法：30只小鼠随机分为对照组、模型组、GBE低、中、高剂量组（50,100,and 200 mg·kg^-1）,每组6只。除对照组外,剩余小鼠腹腔注射APAP （300 mg/kg）一次,随后GBE低、中、高剂量组按照相应剂量灌胃给药,治疗2 d后取材。观察各组肝脏大体情况和肝组织的病理组织学变化;取血测定各组小鼠血清中ALT、AST的活性和TNF-α、IL-6的水平;取肝检测各组肝组织中SOD、MPO的活性和GSH、MDA的含量;通过Western blot检测各组肝组织中Nrf2、HO-1蛋白的表达量。结果：与对照组相比,模型组肝脏明显肿大,病理表现差,血清中ALT、AST、TNF-α、IL-6的水平显著升高（P<0.01）,肝组织中GSH的含量和SOD的活性显著降低（P<0.01）,MDA的含量和MPO的活性显著升高（P<0.01）,Nrf2、HO-1蛋白表达明显下调（P<0.01）。与模型组相比,GBE组肝脏肿大减轻,病理表现有所改善,血清中ALT、AST、TNF-α、IL-6的水平显著降低（P<0.01）,肝组织中GSH的含量和SOD的活性显著提高（P<0.01）,MDA的含量和MPO的活性显著降低（P<0.01）,Nrf2、HO-1蛋白表达上调（P<0.05）,其中高剂量GBE组治疗效果最明显。结论：GBE可对APAP诱导的小鼠急性肝损伤具有保护作用,其作用机制可能是通过Nrf2/HO-1抗氧化途径发挥作用。     

紫檀芪调节Keap-1/Nrf2/HO-1信号通路对非酒精性脂肪肝大鼠氧化应激和细胞凋亡的影响

摘要 目的：研究紫檀芪调节Kelch样ECH关联蛋白1（Keap-1）/核因子E2相关因子2（Nrf2）/血红素加氧酶-1（HO-1）信号通路对非酒精性脂肪肝（NAFLD）大鼠氧化应激和细胞凋亡的影响。方法：将60只SD大鼠随机分为对照组、模型组、紫檀芪低剂量组（30 mg/kg）、紫檀芪高剂量组（60 mg/kg）、紫檀芪（60 mg/kg）+N-（4-（2,3-二氢-1-（2''-甲基苯甲酰）-1H-吲哚-5-基）-5-甲基-2-噻唑基）-1,3-苯并二氧唑-5-乙酰胺（ML385）（30 mg/kg）组，每组12只。模型组与药物干预组大鼠以高脂饲料饲养诱导NAFLD模型，对照组大鼠以普通饲料饲养，各组连续喂养12周。以紫檀芪和ML385分组处理14 d后（对照组以等剂量生理盐水处理），检测各组大鼠脂代谢指标[三酰甘油（TG）、总胆固醇（TC）及游离脂肪酸（FFA）水平]、肝指数、肝功能指标[谷丙转氨酶（ALT）及谷草转氨酶（AST）]水平、血清白细胞介素（IL）-17、IL-6、IL-10、氧化应激指标[丙二醛（MDA）、超氧化物歧化酶（SOD）及过氧化氢酶（CAT）]水平；原位末端标记法（TUNEL）染色检测各组大鼠肝细胞凋亡率；蛋白免疫印迹法检测各组大鼠肝组织凋亡相关蛋白及Keap-1/Nrf2/HO-1通路相关蛋白表达。结果：与对照组相比，模型组大鼠血清IL-10、SOD及CAT水平、肝组织Nrf2、HO-1、Bcl-2表达水平显著降低（P＜0.05），TG、TC及FFA水平、肝指数、ALT及AST水平、血清IL-17、IL-6、MDA水平、肝细胞凋亡率、肝组织Keap-1及Bax表达水平显著升高（P＜0.05）。与模型组相比，紫檀芪低、高剂量组大鼠血清IL-10、SOD及CAT水平、肝组织Nrf2、HO-1、Bcl-2表达水平均升高（P＜0.05），TG、TC及FFA水平、肝指数、ALT及AST水平、血清IL-17、IL-6、MDA水平、肝细胞凋亡率、肝组织Keap-1、Bax表达水平均降低（P＜0.05）；与紫檀芪低剂量组相比，紫檀芪高剂量组大鼠血清IL-10、SOD及CAT水平、肝组织Nrf2、HO-1、Bcl-2表达水平升高（P＜0.05），TG、TC及FFA水平、肝指数、ALT及AST水平、血清IL-17、IL-6、MDA水平、肝细胞凋亡率、肝组织Keap-1及Bax表达水平降低（P＜0.05）；与紫檀芪高剂量组相比，紫檀芪+ML385组大鼠血清IL-10、SOD及CAT水平、肝组织Nrf2、HO-1、Bcl-2表达水平降低（P＜0.05），TG、TC及FFA水平、肝指数、ALT及AST水平、血清IL-17、IL-6、MDA水平、肝细胞凋亡率、肝组织Bax表达水平升高（P＜0.05）。结论：紫檀芪可能通过激活Keap-1/Nrf2/HO-1信号通路，改善NAFLD大鼠脂代谢水平，调节炎症反应及氧化应激，减轻肝组织脂肪变性及细胞凋亡。     

绞股蓝皂苷对奥沙利铂所致大鼠神经毒性保护作用及机制研究

本研究主要探讨绞股蓝皂苷(Gypenoside,GPS)对奥沙利铂所致大鼠周围神经毒性保护作用及其分子机制。将雄性SD大鼠随机分为正常对照组、模型对照组、GPS低、中、高剂量组。除正常对照组外,其他各组均腹腔注射奥沙利铂4 mg/kg,同时模型对照组灌胃给予溶媒5%葡萄糖,GPS低、中和高分别灌胃给予50、100和200 mg/kg GPS,定期检测温度和机械刺激下大鼠行为变化,给药40天后处死大鼠。ELISA检测血浆中NGF含量,Western blot检测L4-5背根神经节中Nrf2及其下游NQO-1和HO-1蛋白表达水平。结果,与正常对照组相比,模型对照组出现明显行为学改变、血浆NGF下降,Western blot检测发现Nrf2及其下游NQO-1和HO-1蛋白表达水平显著下降。而给予GPS后可显著改善大鼠行为学改变; GPS低中高剂量组可上调Nrf2及其下游NQO-1和HO-1水平。综上所述,GPS可改善奥沙利铂所致大鼠周围神经毒性温度和机械刺激下的行为学改变,其机制与上调NGF水平以及Nrf2信号通路有关。     

阿里红多糖通过激活Nrf2/ARE通路改善阿尔茨海默病大鼠海马及脑皮层的氧化应激损伤

探讨阿里红多糖(Fomes officinalis Ames polysaccharides,FOPS)抗氧化应激的作用,并从Nrf2/ARE信号通路研究其作用机制。72只健康雄性SD大鼠称体质量并按随机原则分为空白组、模型组、盐酸多奈哌齐组(0.5 mg/kg)、阿里红多糖高、中、低剂量组(100、50、25 mg/kg),每组12只。采用大鼠双侧海马CA1区注射(5μL/侧)Aβ1-42建立AD大鼠模型,给药30天,Morris水迷宫检测行为学变化,荧光定量RT-qPCR和蛋白免疫印迹法(Western blotting)检测各组大鼠脑皮层和海马组织中结构蛋白Keap1、Nrf2及下游抗氧化蛋白HO-1、NQO1 mRNA及蛋白含量。结果发现,干预30天后,与空白组比较,AD模型组大鼠学习记忆能力显著下降(P<0.01),大鼠海马区及脑皮层Nrf2、NQO1、HO-1的mRNA含量及蛋白表达量显著下降(P<0.01),而Keap1 mRNA含量及蛋白表达量显著升高(P<0.01);与模型组比较,盐酸多奈哌齐和阿里红多糖高、中剂量组大鼠的学习记忆能力显著升高(P<0.01),大鼠海马区及脑皮层Nrf2、NQO1、HO-1 mRNA含量及蛋白表达量显著升高(P<0.05,P<0.01),Keap1 mRNA含量及蛋白表达量显著降低(P<0.05,P<0.01)。研究表明阿里红多糖通过调节Keap1的表达,促进Nrf2激活,诱导NQO1、HO-1的表达,发挥提高机体抗氧化损伤作用,从而改善AD大鼠学习记忆能力。     

虫草发酵菌丝体对胰岛素抵抗大鼠氧化应激的缓解作用

探究虫草发酵菌丝体对胰岛素抵抗(IR)大鼠氧化应激的影响。采用低中高剂量虫草发酵菌丝体(剂量分别为1.65g/kg饲料,3.30g/kg饲料和6.60g/kg饲料)分别干预IR大鼠。口服葡萄糖耐量实验观察不同剂量虫草发酵菌丝体的降糖效果,同时观察血脂、氧化应激水平的变化情况。RT-PCR法测肌肉、肝脏组织氧化应激相关基因Nrf2、HO-1和NQO1mRNA相对表达量,Westernblot法测其蛋白相对表达量。结果发现CM干预能够显著改善IR大鼠空腹血糖、血脂和机体氧化应激水平,肌肉、肝脏组织Nrf2、HO-1和NQO1mRNA相对表达量显著上升,肝脏Nrf2和NQO1蛋白相对表达量显著上调,并且具有剂量依赖性。说明CM具有缓解IR大鼠氧化应激的作用。     

还原型谷胱甘肽对阿霉素致大鼠心脏毒性的保护作用及其机制

目的:探讨还原型谷胱甘肽(GSH)对阿霉素所致大鼠心脏毒性的保护作用及其机制。方法:选取40只健康SD大鼠作为实验动物,将其随机分为4组,即GSH(小剂量)组+阿霉素组(小剂量组)、GSH(大剂量)+阿霉素组(大剂量组)、阿霉素组及生理盐水组,每组各10只。上述前3组均给予阿霉素;小剂量组给予GSH 250 mg/kg;大剂量组给予GSH 500 mg/kg;生理盐水组给予相同体积的生理盐水。末次给药24 h后,应用免疫组化学SP法检测大鼠心肌组织中BAX和BCL-2蛋白的表达情况,应用ELISA法测定大鼠血清中CK(肌酸激酶)、CK-MB(肌酸激酶同工酶)、LDH(乳酸脱氢酶)的含量以及心肌组织中超氧化物歧化酶(SOD)、丙二醛(MDA)的活性,并对实验数据进行统计学分析。结果:1与阿霉素组相比,应用GSH干预的大鼠心肌组织中BCL-2的表达显著升高,BAX的表达显著降低,差异均有统计学意义(P0.05);大、小剂量组间BAX和BCL-2蛋白的表达水平比较无统计学差异(P0.05);2与阿霉素组相比,GSH干预的大鼠血清CK、CK-MB、LDH水平均显著下降,但大、小剂量组间比较无显著性差异(P0.05);3与阿霉素组相比,应用GSH干预的大鼠心肌组织MDA水平降低,SOD活力升高(P0.05),但大、小剂量组间比较无显著性差异(P0.05)。结论:还原型谷胱甘肽能够抑制阿霉素导致的心脏毒性作用,其作用机制可能与提高心肌组织BCL-2蛋白的表达与SOD水平、降低MDA水平以及BAX蛋白的表达有关。     

CYP2E1-mediated oxidative stress regulates HO-1 and GST expression in maneb- and paraquat-treated rat polymorphonuclear leukocytes

Cytochrome P4502E1 (CYP2E1), glutathione-S-transferase A4-4 (GSTA4-4), and inducible nitric oxide synthase (iNOS) are implicated in maneb- and paraquat-induced toxicity leading to various pathological conditions. The study aimed to investigate the role of CYP2E1 in maneb- and paraquat-induced oxidative stress in rat polymorphonuclear leukocytes (PMNs) and its crosstalk with iNOS-mediated nitrosative stress and GSTA4-4-linked protective effect, if any and their consequent links with the nuclear factor erythoid 2-related factor 2 (Nrf2) activation and heme oxygenase-1 (HO-1) expression. Rats were treated with/without maneb and/or paraquat for 1, 2, and 3 weeks along with vehicle controls. Subsets of rats were also treated with diallyl sulfide (DAS) or aminoguanidine (AG) along with the respective controls. Maneb and paraquat augmented the reactive oxygen species (ROS), lipid peroxidation (LPO) and 4-hydroxy nonenal (4-HNE) contents, and superoxide dismutase (SOD) activity in the PMNs. However, maneb and paraquat attenuated the reduced glutathione (GSH) level and the expression/activity of total GST and GST-pi. Maneb and paraquat increased the expression/activity of CYP2E1, GSTA4-4, iNOS, Nrf2 and HO-1, and nitrite content. CYP2E1 inhibitor, DAS noticeably alleviated maneb- and paraquat-induced ROS, LPO, 4-HNE, SOD, Nrf2 and HO-1, GST, GSH, and GST-pi while iNOS, nitrite content and GSTA4-4 levels were unchanged. Conversely, AG, an iNOS inhibitor, attenuated maneb- and paraquat-directed changes in nitrite, LPO, iNOS but it did not alter ROS, GSH, SOD, GST, GST-pi, Nrf2, HO-1, CYP2E1, and GSTA4-4. The results demonstrate that CYP2E1 induces iNOS-independent free radical generation and subsequently modulates the Nrf2-dependent HO-1 and 4-HNE-mediated GST expression in maneb- and paraquat-treated PMNs.     

基于PERK/Nrf2/HO-1信号通路研究瑞马唑仑对心肌缺血再灌注损伤大鼠铁死亡的影响

摘要 目的：基于蛋白激酶R样内质网激酶（PERK）/核因子E2相关因子2（Nrf2）/血红素氧合酶-1（HO-1）信号通路探究瑞马唑仑对心肌缺血再灌注损伤（MIRI）大鼠铁死亡的影响。方法：将90只SD大鼠随机分为假手术（Sham）组、MIRI组、低剂量-瑞马唑仑组（L-瑞马唑仑组，5 mg/kg）、高剂量-瑞马唑仑组（H-瑞马唑仑组，20 mg/kg）、H-瑞马唑仑+PERK抑制剂组（瑞马唑仑20 mg/kg+GSK2606414 1 mg/kg），每组18只。采用结扎冠状动脉左前降支（LAD）0.5 h、再灌注2 h制备MIRI大鼠模型，于再灌注2 h后即刻尾静脉注射给药，再灌注24 h后进行组织取材。酶联免疫吸附（ELISA）法检测血清心肌损伤标志物[肌酸激酶同工酶（CK-MB）、心肌肌钙蛋白I（cTnI）]水平；HE染色观察心肌组织病理改变；Tunel染色检测心肌细胞凋亡；透射电镜观察心肌细胞超微结构变化；检测心肌组织中铁死亡相关标志物[铁、活性氧（ROS）、谷胱甘肽（GSH）、丙二醛（MDA）]水平；蛋白质印迹法（Western Blot）检测心肌组织中PERK/Nrf2/HO-1信号通路相关蛋白表达。结果：与Sham组相比，MIRI组心肌结构受损，纤维排列紊乱，线粒体呈现显著的铁死亡特征（膜固缩，膜密度增加，嵴减少），血清中CK-MB、cTnI水平，心肌细胞凋亡率及心肌组织中铁、ROS、MDA水平升高（P<0.05），心肌组织中GSH水平及p-PERK/PERK、核Nrf2/Nrf2、HO-1蛋白表达降低（P<0.05）；与MIRI组相比，L-瑞马唑仑组和H-瑞马唑仑组心肌组织上述病理改变明显减轻，血清CK-MB、cTnI水平，心肌细胞凋亡率及心肌组织中铁、ROS、MDA水平降低（P<0.05），心肌组织中GSH水平及p-PERK/PERK、核Nrf2/Nrf2、HO-1蛋白表达升高（P<0.05）；与H-瑞马唑仑组相比，H-瑞马唑仑+PERK抑制剂组心肌组织上述病理改变加重，血清CK-MB、cTnI水平，心肌细胞凋亡率及心肌组织中铁、ROS、MDA水平升高（P<0.05），心肌组织中GSH水平及p-PERK/PERK、核Nrf2/Nrf2、HO-1蛋白表达降低（P<0.05）。结论：瑞马唑仑可通过抑制铁死亡减轻大鼠MIRI，可能通过激活PERK/Nrf2/HO-1信号通路而实现。     

Effects of different exercise durations on Keap1-Nrf2-ARE pathway activation in mouse skeletal muscle

Abstract

The purpose of this study was to investigate the effects of acute exercise stress on the nuclear factor-erythroid2 p45-related factor 2 (Nrf2)/antioxidant response element (ARE) transactivation, Kelch-like ECH-associated protein 1 (Keap1) cytosolic protein and Nrf2 nucleoprotein expressions, Nrf2 target genes mRNA expressions, and glutathione redox (GSH/GSSG) ratio level; with a particular focus on the changes in Keap1-Nrf2-ARE pathway activation following different durations of exercise. Wild-type mice (C57BL/6J, two months old) were separated into one-hour and six-hour treadmill running groups, as well as a non-exercise control group (n = 10 in each group). Measurements of Nrf2/ARE transactivation, Nrf2 nucleoprotein expressions, Keap1 cytosolic protein expression, Nrf2 target genes’ mRNA expressions (superoxide dismutase-1 [SOD1], superoxide dismutase-2 [SOD2], γ-glutamyl cysteine ligase-modulatory [GCLm], γ-glutamyl cysteine ligase-catalytic [GCLc], glutathione reductase [GR], glutathione peroxidase-1 [Gpx1], catalase [CAT], and hemoxygenase-1 [Ho-1]), and GSH/GSSG ratio were carried out immediately after exercise. The results showed significant increases in Keap1-Nrf2-ARE pathway activation and the mRNA expressions of six measured enzymes in skeletal muscle after six hours of exercise; while in the one-hour exercise group, there was no change in Keap1-Nrf2-ARE pathway activation and only two enzymes’ mRNA expressions were increased. It is suggested that the changes in Keap1-Nrf2-ARE pathway activation and its target genes’ mRNA expressions were dependent on the exercise duration, with longer duration associated with higher responses.     

β-Caryophyllene Attenuates Focal Cerebral Ischemia-Reperfusion Injury by Nrf2/HO-1 Pathway in Rats

This study aimed to identify the effect of β-caryophyllene (BCP) pretreatment and elucidate the Nrf2/HO-1 signaling mechanism after focal cerebral ischemia-reperfusion (I-R) injury in rats. Adult male Sprague–Dawley rats were randomly assigned to the sham-operated group, I-R group and BCP pretreated I-R group. At 24 h after reperfusion, neurological deficits and infarct volume were evaluated. Pathological changes of neuron in hippocampuses were observed by Nissil staining and transmission electron microscopy (TEM). Oxidative stress was assessed by malondialdehyde (MDA) level, lipid peroxidation (LPO), nitric oxide (NO), superoxide dismutase (SOD) and Catalase (CAT) activity. The expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were analysed by Western blotting and real-time quantitative polymerase chain reaction (Q-PCR). The protein expression of Bcl-2 and Bax was determined by immunohistochemistry. Apoptotic cells were detected using TUNEL staining. In I-R group, neurological deficit scores, cerebral infarct volume, MDA levels, LPO content, NO level, expression of Bax and TUNEL-positive cells were found to be increased at 24 h after I-R injury, while SOD activity, CAT activity and expression of Bcl-2 were decreased. However, results in the BCP pretreatment groups were reversed. And the protein and mRNA expressions of Nrf2 and HO-1 were significantly up-regulated in the BCP pretreated I-R group. Results of Nissil staining and TEM scan manifested that BCP remarkablely improved neuronal injury after I-R in rats. All the above suggested that BCP pretreatment played a neuroprotective role in cerebral I-R injury, which might be exerted by upregulating the expression of Nrf2 and HO-1 to ameliorate oxidative damage and neuronal apoptosis.     

Targeting PI3K/p-Akt/eNOS,Nrf2/HO-1, and NF-κB/p53 signaling pathways by angiotensin 1–7 protects against liver injury induced by ischemia–reperfusion in rats

The liver is an important organ, and hepatic ischemia–reperfusion (IR) injury is a frequent pathophysiological process that can cause significant morbidity and mortality. Thus, our study aimed to investigate the effect of targeting PI3K/p-Akt/eNOS (phosphoinositide 3-kinase/phospho-protein kinase B/endothelial nitric oxide synthase), Nrf2/HO-1 (nuclear factor-erythroid 2-related factor-2/heme oxygenase-1), and NF-κB/p53 (nuclear factor-κB/tumor protein 53) signaling pathways by using angiotensin (1–7) [ang-(1–7)] against hepatic injury induced by IR. Thirty-two male rats were included in sham group, ang-(1–7)-treated group, hepatic IR group, and hepatic IR group treated with ang-(1–7). The levels of hepatic ang-(1–7), angiotensin II (Ang II), angiotensin-converting enzyme 2 (ACE2), HO-1, malondialdehyde (MDA), PI3K, and p-Akt were assessed. The expressions of eNOS and B-cell leukemia/lymphoma-2 (BCL-2) in the liver were determined. Histological assessment and immunohistochemical expression of NF-κB, p53, and Nrf2 were carried out. The levels of reduced glutathione (GSH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in serum were estimated. Results showed that administration of ang-(1–7) to hepatic IR rats led to significant amelioration of hepatic damage through a histological evaluation that was associated with significant upregulation of the expressions of PI3K/p-Akt/eNOS and Nrf2/HO-1 with downregulation of NF-κB/p53 signaling pathways. In conclusion, PI3K/p-Akt/eNOS and Nrf2/HO-1 signaling pathways are involved in the protective effects of ang-(1–7) against hepatic damage induced by IR. Therefore, ang-(1–7) can be used to prevent hepatic IR, which occurs in certain conditions such as liver transplantation, hemorrhagic shock, and severe infection.     

Bama miniature pigs’ liver possess great heat tolerance through upregulation of Nrf2-mediated antioxidative enzymes

The liver is one of the most crucial organs affected by high ambient temperature. Bama miniature pig show a heat tolerance in hot summer months. However, the physiological condition of liver under high ambient temperature has not been well elucidated in Bama miniature pig. Here we performed an experiment to investigate the effects of high ambient temperature on liver function, redox status and Nrf2 antioxidant pathway in Bama miniature pigs. Twelve pigs were randomly divided into two groups and separately exposed to the neutral temperature (NT, 25 °C) and high temperature (HT, 40 °C) for 8 days. The hepatic damage marker, such as total bilirubin (TBIL), alkaline phosphatase (AKP), γ-glutamyl transpeptidas (γ-GT), alanine transaminase (ALT) and aspartase transminase (AST), didn’t reach statistical significance between NT and HT group. Moreover, abnormal observation of hepatic histology and hepatocyte ultrastructure were not detected in HT group. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) as well as glutathione (GSH) content, were dramatically increased after heat exposure. Heat treatment didn’t increase hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) concentrations. The expression of Nrf2-regulated genes, such as nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H: quinine oxidoreductase 1 (NQO1), superoxide dismutase 1 (SOD1), heme oxygenase-1 (HO-1) and glutamate cysteine ligase catalytic subunit (GCLC), were significantly increased in HT group. Nrf2 protein was accumulated in HT group through immunohistochemical analysis. The current data provide clear evidence that Bama miniature pigs’ liver possess great capacity of heat tolerance, which related to activation of Nrf2 antioxidant pathway.     

Sex-specific divergence of antioxidant pathways in fetal brain,liver, and skeletal muscles

The sex-specific divergence of antioxidant pathways in fetal organs of opposite-sex twin is unknown and remains urgently in need of investigation. Such study faces many challenges, mainly the ethical impossibility of obtaining human fetal organs. Opposite-sex sheep twins represent a unique model for studying a sex dimorphism for antioxidant systems. The activity of total superoxide dismutase (SOD), SOD1, SOD2, glutathione peroxidase (GPX), glutathione reductase (GR) and catalase (CAT), the content of total glutathione, reduced glutathione (GSH), and oxidized glutathione (GSSG) were measured in brain, lung, liver, kidney, and skeletal muscles of female and male fetuses collected from sheep twin pregnancies at day 65 of gestation. Lipid peroxidation was assessed by measuring melondialdehyde (MDA) tissue content. Male brain has greater total SOD and SOD1 activities than female brain. Female liver has greater SOD2 activity than male liver. Male liver has greater GR activity than female liver. Male liver has higher total GSH and GSSG content than female liver. Male skeletal muscles have higher total GSH, GSH, and GSSG content than female skeletal muscles. Female brain and liver have higher MDA content than male brain and liver. This is the first report of a sex dimorphism for fetal organ antioxidative pathways. Brain, liver, and skeletal muscles of male and female fetuses display distinct antioxidant pathways. Such sexually dimorphic responses to early life oxidative stress might be involved in the sex-related difference in fetal development that may have a long-term effect on offspring. Our study urges researchers to take into consideration the importance of sex as a biologic variable in their investigations.