Red cell antioxidant enzymes and prognostic indexes in patients with burns

Red cell superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) were measured in 66 burned patients (57 men, 9 women, age 16–78 years). BSAB varied from 15 to 93% and ABSI from 3 to 14 points. In the first week after injury the activity of SOD was significantly decreased as compared with the activity of the enzymes in the control group and was also below the reference values. Later the activity of SOD increased up to the normal range. The activity of CAT followed a similar pattern but the differences were not significant. No significant changes in red cell GPX were found during the monitored period. We did not find any significant association between the antioxidant enzyme activities and the markers of burns severity. On the other side there was a significant indirect association between the change of SOD activity (calculated as a difference between the first week values after the injury and the activities measured later) and BSAB.     

小檗碱通过激活 Nrf2-HO-1/GPX4 通路抑制小鼠海马神经元HT22细胞的铁死亡

目的 探讨小檗碱对于Erastin诱导小鼠海马神经元HT22细胞的铁死亡的保护作用及其可能机制。方法 以HT22小鼠海马神经元细胞为研究对象,分为对照组、Erastin模型组、Erastin+30 μmol/L BBR组、Erastin+60 μmol/L BBR组。采用CCK-8法、特异性 Fe2+ 荧光探针、荧光染料（DAPI）检测和荧光探针（H2DCFH-DA）检测各实验组细胞的增殖情况、活性铁水平、细胞凋亡和活性氧（ROS）变化。 RT-qPCR和Western blot分别检测各实验组细胞的Nrf2、HO-1、GPX4 mRNA和蛋白表达情况。以60 μmol BBR的最适浓度来进一步探究其作用机制,分为对照组、Erastin模型组、Erastin+60 μmol/L BBR组、Erastin+60 μmol/LBBR+2 μmol Nrf2抑制剂 ML385组。通过使用荧光探针和Western blot检测Nrf2抑制剂（ML385）作用后的活性铁的水平、活性氧含量以及Nrf2、HO-1、GPX4蛋白的表达来验证小檗碱调节的Nrf2-HO-1/GPX4通路对Erastin处理的HT22细胞的保护作用。结果 0.5 μmol/L Erastin作用于HT22细胞8 h,细胞存活率与对照组相比显著被抑制（P<0.05）;同时细胞凋亡、ROS以及活性铁含量增加（P<0.05）。与Erastin组比较,Erastin+30 μmol/L BBR组和Erastin+60 μmol/L BBR组的细胞存活率明显升高（P<0.05）,同时显著降低细胞凋亡、ROS以及活性铁含量（P<0.05）。小檗碱增加 HT22细胞中Nrf2、HO-1、GPX4基因及蛋白的 表达量（P<0.05）。加入Nrf2抑制剂ML385后,Nrf2-HO-1/GPX4通路被抑制,并且ROS以及活性铁含量升高（P<0.05）。结论 Erastin诱导HT22细胞发生铁死亡,小檗碱抑制Erastin诱导的铁死亡,可能机制是激活了Nrf2-HO-1/GPX4通路。     

直肠癌与GPX2表达关系的研究进展

直肠癌是严重危害人类健康的一类疾病,大多数直肠癌患者诊断时为局部进展期直肠癌,新辅助放化疗是这类患者的标准治疗,新辅助放化疗的疗效直接影响患者预后。GPX2（胃肠道谷胱甘肽过氧化物酶）是一类参与氧化还原反应的蛋白质,GPX2的表达水平与患者放疗敏感性直接相关,除此以外,GPX2也在结直肠炎症性疾病中发挥重要作用,本文对直肠癌中GPX2的表达与治疗的研究进展进行系统的综述。     

不同浓度的氟伐他汀对卵巢癌SKOV3细胞中GPX4蛋白表达的影响

目的:探讨不同浓度的氟伐他汀对卵巢癌SKOV3细胞中脂质过氧化物磷脂谷胱甘肽过氧化物酶4（phospholipid glutathione peroxidase 4,GPX4)蛋白表达的影响。方法:采用细胞免疫组化、qRT-PCR和Western Blot技术检测卵巢癌SKOV3细胞中GPX4 mRNA和蛋白的表达。结果:随着氟伐他汀的浓度增加（0 mmol/L、3 mmol/L、10 mmol/L、30 mmol/L）,SKOV3细胞数目减少,氟伐他汀呈浓度依赖性抑制SKOV3细胞的增殖;SKOV3细胞中GPX4蛋白和mRNA的相对表达量明显上调。结论:氟伐他汀抑制卵巢癌细胞的增殖转移与其上调卵巢癌细胞中GPX4的表达有关。     

miR-338通过靶向GPX4抑制非小细胞肺癌细胞增殖

目的:探讨miRNA-338（miR-338）通过靶向调控谷胱甘肽过氧化物酶4（GPX4）表达在非小细胞肺癌(non-small cell lung cancer,NSCLC)增殖中的作用及机制研究。方法:通过实时定量聚合酶链式反应（qRT-PCR）检测非小细胞肺癌组织、癌旁、细胞系及对照细胞系中miR-338及GPX4 mRNA的表达水平;通过Western Blot检测非小细胞肺癌组织、癌旁、细胞系及对照细胞系中GPX4蛋白水平;通过荧光素酶报告基因时间验证miR-338直接靶向调节GPX4的表达;通过CCK-8探索miR-338是否通过调节铁死亡影响肿瘤细胞增殖;通过试剂盒检测细胞脂质氧化和活性氧水平。结果:NSCLC组织和细胞系中miR-338表达水平低于癌旁组织和对照细胞系;NSCLC组织和细胞系中GPX4 mRNA及蛋白表达水平高于癌旁组织和对照细胞系;Starbase软件分析发现GPX4 mRNA序列中含有miR-338特异作用位点,荧光素酶报告基因实验结果证实miR-338直接靶向调节GPX4表达;过表达miR-338提高肿瘤细胞中脂质氧化及活性氧水平,并抑制肿瘤细胞增殖;而铁死亡抑制剂预处理可以逆转miR-338的抑癌作用。结论:miR-338通过负向调控GPX4表达进而促进肿瘤细胞铁死亡,最终抑制NSCLC细胞增殖。     

Cellular energetics and glutathione status in NRK-52E cells: toxicological implications

Cellular energetics and redox status were evaluated in NRK-52E cells, a stable cell line derived from rat proximal tubules. To assess toxicological implications of these properties, susceptibility to apoptosis induced by S-(1,2-dichlorovinyl)-L-cysteine (DCVC), a well-known mitochondrial and renal cytotoxicant, was studied. Cells exhibited high activities of several glutathione (GSH)-dependent enzymes, including gamma-glutamylcysteine synthetase, GSH peroxidase, glutathione disulfide reductase, and GSH S-transferase, but very low activities of gamma-glutamyltransferase and alkaline phosphatase, consistent with a low content of brush-border microvilli. Uptake and total cellular accumulation of [14C]alpha-methylglucose was significantly higher when cells were exposed at the basolateral as compared to the brush-border membrane. Similarly, uptake of GSH was nearly 2-fold higher across the basolateral than the brush-border membrane. High activities of (Na(+)+K(+))-ATPase and malic dehydrogenase, but low activities of other mitochondrial enzymes, respiration, and transport of GSH and dicarboxylates into mitochondria were observed. Examination of mitochondrial density by confocal microscopy, using a fluorescent marker (MitoTracker Orange), indicated that NRK-52E cells contain a much lower content of mitochondria than rat renal proximal tubules in vivo. Incubation of cells with DCVC caused time- and concentration-dependent ATP depletion that was largely dependent on transport and bioactivation, as observed in the rat, on induction of apoptosis, and on morphological damage. Comparison with primary cultures of rat and human proximal tubular cells suggests that the NRK-52E cells are modestly less sensitive to DCVC. In most respects, however, NRK-52E cells exhibited functions similar to those of the rat renal proximal tubule in vivo.     

Metabolic, hormonal, oxidative, and inflammatory factors in pediatric obesity-related liver disease

OBJECTIVE: To examine the role of metabolic, hormonal, oxidative, and inflammatory factors in pediatric obesity-related liver disease. STUDY DESIGN: In 50 obese children (age 7 to 14 years) with (n = 20, group 1) or without (n = 30, group 2) hypertransaminasemia and ultrasonographic liver brightness, we studied insulin resistance (fasting glucose/insulin ratio [FGIR]) and serum levels of leptin, iron, transferrin, ferritin, C-reactive protein (CRP), white blood cell (WBC) count, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, C282Y and H63D mutations, and erythrocytic glutathione peroxidase (GPX) activity. RESULTS: FGIR (6.7 +/- 4.1 vs 9.2 +/- 5.2; P = .02), serum ferritin (88.8 +/- 36.0 vs 39.9 +/- 24.0 ng/mL; P = .0001), serum CRP (5.4 +/- 6.0 vs 1.1 +/- 1.6 mg/dL; P = 0.004), and GPX (8.4 +/- 0.9 vs 5.0 +/- 0.5 U/g Hb; P = .05) were significantly higher and more frequently deranged in group 1 than in group 2. FGIR, ferritin, and CRP values were simultaneously deranged in 41% of the group 1 patients and in none of the group 2 patients ( P = .098). Serum leptin, iron, and transferrin, WBC, TNF-alpha, IL-6, and C282Y and H63D mutations were similar in the 2 groups. CONCLUSIONS: Insulin resistance, oxidative stress, and low-grade systemic inflammatory status are implicated in pediatric obesity-related liver disease. These findings may be useful in planning pathophysiologically based therapeutic trials for hepatopathic obese children who are unable to follow hypocaloric diets.     

Hepatoprotective effect and antioxidant role of sun, sulphited-dried apricot (Prunus armeniaca L.) and its kernel against ethanol-induced oxidative stress in rats

The present study was carried to evaluate the hepatoprotective effect and antioxidant role of sun, sulphited-dried apricot and its kernel against ethanol-induced oxidative stress. The hepatopreventive and antioxidant potential of the plant’s supplementations were evaluated by measuring level of serum liver damage marker enzymes (AST, ALT, GGT and LDH), antioxidant defense systems (GSH, GR, SOD, GST and GPX) and MDA content in various tissues of rats. Eight experimental groups: I (control), II (20% ethanol), III (ethanol + 15% sun-dried apricot), IV (ethanol + 30% sun dried). V (ethanol + 15% sulphited-dried), VI (ethanol + 30% sulphited-dried), VII (ethanol + 15% kernel) and VIII (ethanol + 30% kernel). According to the results, the levels of serum enzymes increased significantly in the II group as compared to those of I group, but they decreased in the III, IV, V and VI groups as compared to those of II group. Also, administration of sun and sulphited-dried apricot supplementation restored the ethanol-induced imbalance between MDA and antioxidant system towards near normal particularly in tissues but not its kernel. It is concluded that apricot has a hepatoprotective effect in rats with ethanol, probably acting by promoting the antioxidative defense systems.