Pyrrolidine dithiocarbamate reduces ischemia-reperfusion injury of the small intestine

AIM: To evaluate whether pyrrolidine dithiocarbamate (PDTC), an enhancer of HO production, attenuates intestinal IR injury. METHODS: Eighteen male rats were randomly allocated into three groups: (a) sham; (b) IR, consisting of 30 min of intestinal ischemia, followed by 2-h period of reperfusion; and (c) PDTC treatment before IR. Intestinal microvascular perfusion (IMP) was monitored continuously by laser Doppler flowmetry. At the end of the reperfusion, serum samples for lactate dehydrogenase (LDH) levels and biopsies of ileum were obtained. HO activity in the ileum was assessed at the end of the reperfusion period. RESULTS: At the end of the reperfusion in the IR group, IMP recovered partially to 42.5% of baseline (P<0.05 vs sham), whereas PDTC improved IMP to 67.3% of baseline (P<0.01 vs IR). There was a twofold increase in HO activity in PDTC group (2 062.66±106.11) as compared to IR (842.3±85.12) (P<0.001). LDH was significantly reduced (P<0.001) in PDTC group (585.6±102.4) as compared to IR group (1 973.8±306.5). Histological examination showed that the ileal mucosa was significantly less injured in PDTC group as compared with IR group. CONCLUSION: Our study demonstrates that PDTC improves the IMP and attenuates IR injury of the intestine possibly via HO production. Additional studies are warranted to evaluate the clinical efficacy of PDTC in the prevention of IR injury of the small intestine.     

Ribavirin induced hemolysis: A novel mechanism of action against chronic hepatitis C virus infection

Hepatitis C virus(HCV)is not usually cleared by our immune system,leading to the development of chronic hepatitis C infection.Chronic HCV induces the production of various cytokines,predominantly by Kupffer cells(KCs),and creates a pro-inflammatory state in the liver.The chronic dysregulated production of interferon(IFN)and other cytokines by KCs also promotes innate immune tolerance.Ribavirin(RBV)monotherapy has been shown to decrease inflammation in liver of patients with chronic hepatitis C.Sustained virological response(SVR)is significantly higher when IFN is combined with RBV in chronic HCV(c HCV)infection.However,the mechanism of their synergy remains unclear.Previous theories have attempted to explain the anti-HCV effect based on direct action of RBV alone on the virus or on the immune system;however,these theories have serious shortcomings.We propose that hemolysis,which universally occurs with RBV therapy and which is considered a limiting side effect,is precisely the mechanism by which the anti-HCV effect is exerted.Passive hemolysis results in anti-inflammatory/antiviral actions within the liver that disrupt the innate immune tolerance,leading to the synergy ofRBV with IFN-α.Ribavirin-induced hemolysis floods the hepatocytes and KCs with heme,which is metabolized and detoxified by heme oxygenase-1(HMOX1)to carbon monoxide(CO),biliverdin and free iron(which induces ferritin).These metabolites of heme possess anti-inflammatory and antioxidant properties.Thus,HMOX1 plays an extremely important anti-oxidant,anti-inflammatory and cytoprotective role,particularly in KCs and hepatocytes.HMOX1 has been noted to have anti-viral effects in hepatitis C infected cell lines.Additionally,it has been shown to enhance the response to IFN-αby restoring interferon-stimulated genes(ISGs).This mechanism can be clinically corroborated by the following observations that have been found in patients undergoing RBV/IFN combination therapy for c HCV:(1)SVR rates are higher in patients who develop anemia;(2)once anemia(due to hemolysis)occurs,the SVR rate does not depend on the treatment utilized to manage anemia;and(3)ribavirin analogs,such as taribavirin and levovirin,which increase intrahepatic ribavirin levels and which produce lesser hemolysis,are inferior to ribavirin for treating c HCV.This mechanism can also explain the observed RBV synergy with direct antiviral agents.This hypothesis is testable and may lead to newer and safer medications for treating c HCV infection.     

血红素氧化酶1与慢性阻塞性肺疾病的研究进展

慢性阻塞性肺疾病(COPD)是以持续气流受限为特征的可以预防和治疗的呼吸道疾病。其发生机制尚未完全明确,近年来许多研究表明氧化应激、基因多态性在其发生、发展过程中起到非常重要的作用。血红素加氧酶1(HO-1)作为体内重要的氧化还原酶,与COPD关系密切。本文将从HO-1与COPD的发生、发展、治疗及预后等方面的关系进行综述,以期为COPD的诊断、治疗及管理提供新思路。     

姜黄素对糖尿病大鼠肾脏的保护作用及对血红素加氧酶表达的影响

目的:探讨姜黄素对糖尿病大鼠肾脏病变的作用及对肾脏血红素加氧酶-1(HO-1)表达的影响。方法:诱导大鼠糖尿病后,随机分为对照组(n=10)及治疗组(n=10),比较各组的血生化、尿微量白蛋白排泄量。采用逆转录多聚酶链反应(RT-PCR)检测HO-1 mRNA。用免疫组化检测HO-1蛋白的定位和表达水平。结果:糖尿病大鼠内生肌酐清除率(Ccr)、尿微量白蛋白(mAlb)排泄量较正常鼠增多,HO-1 mRNA和蛋白表达无明显上调。HO-1蛋白主要分布于肾小管、髓质的集合管及髓袢的上皮细胞中,肾小球表达极少。姜黄素治疗能明显降低Ccr,减少mAlb排泄量,诱导HO-1 mRNA和蛋白的表达。结论:姜黄素对糖尿病大鼠肾脏病变具有明显的防治作用,其机制可能是通过诱导HO-1的表达。     

Influence of bradykinin B1 and B2 receptors in the immune response triggered by renal ischemia–reperfusion injury

Bradykinin B1 receptors are exclusively expressed in inflamed tissues. For this reason, they have been related with the outcomes of several pathologies. Ischemia–reperfusion injury is caused by the activation of inflammatory and cytoprotective genes, such as macrophage chemoattractant protein-1 and heme oxygenase-1, respectively. This study was aimed to analyze the involvement of bradykinin B1 and B2 receptors (B1R and B2R) in tissue response after renal ischemia–reperfusion injury. For that, B1R (B1−/−), B2R (B2−/−) knockout animals and its control (wild-type mice, B1B2+/+) were subjected to renal bilateral ischemia, followed by 24, 48 and 120 h of reperfusion. At these time points, blood serum samples were collected for creatinine and urea dosages. Kidneys were harvested for histology and molecular analyses by real-time PCR. At 24 and 48 h of reperfusion, B1−/− group resulted in the lowest serum creatinine and urea levels, indicating less renal damage, which was proved by renal histology. Renal protection associated with B1−/− mice was also related with higher expression of HO-1 and lower expression of MCP-1. In conclusion, the absence of B1R had a protective role against inflammatory responses developed after renal ischemia–reperfusion injury.     

内毒素攻击大鼠肺泡巨噬细胞时HO-1对高尔基体应激的影响

目的探讨内毒素诱导大鼠肺泡巨噬细胞损伤时血红素加氧酶1（HO-1）对高尔基体应激的影响。方法体外培养大鼠肺泡巨噬细胞,采用脂多糖（LPS）诱导大鼠肺泡巨噬细胞建立细胞损伤模型。使用CCK-8法检测细胞活力;使用DCFH-DA探针检测细胞内活性氧簇（ROS）的生成;使用生物化学方法检测超氧化物歧化酶（SOD）活性和丙二醛（MDA）水平;使用TUNEL染色和凋亡相关蛋白caspase-3/7活性检测试剂盒检测细胞凋亡;使用RT-qPCR和Westernblot法检测HO-1和高尔基体磷蛋白3（GOLPH3）的表达;使用Westernblot法检测高尔基体结构相关蛋白GM130、golgin-97和mannosidaseII的表达。使用小干扰RNA（siRNA）沉默HO-1后,重复以上检测。结果LPS刺激肺泡巨噬细胞下调细胞活力、SOD活性及GM130、golgin-97和mannosidaseII表达水平,上调ROS和MDA含量及HO-1和GOLPH3表达水平,并导致TUNEL标记阳性细胞数增多,caspase-3/7活性增强（P<0.05）;HO-1基因沉默后,细胞活力、SOD活性及GM130、golgin-97和mannosidaseII表达显著下降,ROS和MDA含量及GOLPH3表达显著上升,TUNEL标记阳性细胞数增多,caspase-3/-7活性显著增强（P<0.05）。结论内毒素诱导大鼠肺泡巨噬细胞损伤时,HO-1可减轻氧化应激和高尔基体应激反应,减少细胞凋亡。     

苦参总黄酮调控Nrf2/HO-1通路对肝纤维化大鼠的机制研究

目的探究苦参总黄酮（TF-SF）是否通过调控核因子E2相关因子2/血红素加氧酶1（Nrf2/HO-1）通路影响大鼠肝纤维化（HF）。方法将SD大鼠随机分为对照组、HF组、低剂量苦参总黄酮组、中剂量苦参总黄酮组、高剂量苦参总黄酮组及高剂量苦参总黄酮+全反式维甲酸（Nrf2抑制剂）组,每组10只;四氯化碳-花生油溶液灌胃饲养8周构建HF大鼠模型,于第9周开始低、中、高剂量苦参总黄酮组及高剂量苦参总黄酮+全反式维甲酸组大鼠分别给予相应等剂量药物进行灌胃,而对照组和HF组大鼠予以等体积生理盐水灌胃（每天1次）,为期4周,实验结束后观察各组大鼠一般情况。ELISA法检测血清超氧化物歧化酶（SOD）、丙二醛（MDA）、谷胱甘肽过氧化物酶（GSH-Px）、天冬氨酸氨基转移酶（AST）、丙氨酸氨基转移酶（ALT）、透明质酸（HA）、Ⅳ型胶原（Ⅳ-C）、层黏连蛋白（LN）和Ⅲ型前胶原肽（PIIIP）水平;HE及Masson染色观察大鼠肝脏组织病理学情况;Westernblot检测大鼠肝脏组织中Nrf2/HO-1通路蛋白表达水平;real-timePCR检测肝脏组织中Nrf2和HO-1mRNA表达水平。结果与对照组相比,HF组大鼠活动迟钝、体态瘦弱、食欲不振,肝脏质地发硬、边缘钝化、颜色暗淡且被膜缺乏;与HF组相比,低、中、高剂量苦参总黄酮组大鼠活动、饮食及肝脏形态均得到改善;与高剂量苦参总黄酮组相比,高剂量苦参总黄酮+全反式维甲酸组大鼠活动、饮食及肝脏不良状况加重。与对照组相比,HF组大鼠饮食量,饮水量,体重,血清SOD和GSH-Px水平,以及肝脏组织Nrf2和HO-1蛋白及mRNA水平均显著降低,而肝脏重量,血清MDA、AST、ALT、HA、Ⅳ-C、LN和PIIIP水平,以及HF分期和半定量评分均显著增加（P<0.05）;与HF组相比,低、中、高剂量苦参总黄酮组大鼠饮食量,饮水量,体重,血清SOD和GSH-Px水平,以及肝脏组织Nrf2和HO-1蛋白及mRNA水平均显著增加,而肝脏重量,血清MDA、AST、ALT、HA、Ⅳ-C、LN和PIIIP水平,以及HF分期和半定量评分均显著降低,均呈苦参总黄酮剂量依赖性（P<0.05）;全反式维甲酸可逆转苦参总黄酮对肝脏纤维化的缓解。结论苦参总黄酮通过激活Nrf2/HO-1通路起到抗大鼠HF的作用。     

HO-1/CO径路在肺缺血-再灌注损伤中的作用

目的：探讨血红素氧合酶-1（HO-1）/一氧化碳（CO）径路在肺缺血-再灌注损伤中的作用。 方法： 采用在体兔单肺原位缺血-再灌注模型。实验兔40只，随机均分为假手术对照（C）组、肺缺血-再灌注（I-R）组、肺缺血-再灌注加氯铁血红素(H)组和肺缺血-再灌注加锌原卟啉(Z)组。分别在缺血前、缺血后、再灌注1 h、2 h、3 h抽血，检测一氧化碳血红蛋白(COHb)浓度。实验结束时取肺组织检测湿干重比（W/D）、肺泡损伤率（IAR），观察肺组织超微结构的改变、HO-1的活力、表达部位及强度。 结果： 血浆COHb浓度，I-R组、H组明显高于C组，以H组为著（P<0.01）；H组、Z组显著高于、低于I-R组（P<0.01）。肺组织HO-1活力H组最高，其次是I-R组，Z组和C组最低（P<0.05和P<0.01）。I-R组、H组、Z组HO-1在肺血管内皮、部分血管平滑肌、外膜层及部分气道上皮均有阳性表达，明显高于C组，尤以H组最为明显（P<0.01）。W/D、IAR值，I-R组和Z组均明显高于C组，尤以Z组为著，H组虽较C组为高，但显著低于IR组和Z组（P<0.05和P<0.01）。肺组织形态学异常改变，以Z组为著，H组较轻。 结论： HO-1/CO径路对缺血-再灌注肺发挥积极的保护作用。     

Atorvastatin Attenuates TNF-alpha Production via Heme Oxygenase-1 Pathway in LPS-stimulated RAW264.7 Macrophages

Objective To assess the effect of atorvastatin on lipopolysaccharide(LPS)-induced TNF-α production in RAW264.7 macrophages. Methods RAW264.7 macrophages were treated in different LPS concentrations or at different time points with or without atorvastatin. TNF-α level in supernatant was measured. Expressions of TNF-α mRNA and protein and heme oxygenase-1(HO-1) were detected by ELISA, PCR, and Western blot, respectively. HO activity was assayed. Results LPS significantly increased the TNF-α expression and secretion in a dose- and time-dependent manner. The HO-1 activity and HO-1 expression level were significantly higher after atorvastatin treatment than before atorvastatin treatment and attenuated by SB203580 and PD98059 but not by SP600125, suggesting that the ERK and p38 mitogen-activated protein kinase(MAPK) pathways participate in regulating the above-mentioned effects of atorvastatin. Moreover, the HO-1 activity suppressed by SnPP or the HO-1 expression inhibited by siRNA significantly attenuated the effect of atorvastatin on TNF-α expression and production in LPS-stimulated macrophages. Conclusion Atorvastatin can attenuate LPS-induced TNF-α expression and production by activating HO-1 via the ERK and p38 MAPK pathways, suggesting that atorvastatin can be used in treatment of inflammatory diseases such as sepsis, especially in those with atherosclerotic diseases.     

Ferulic acid: Pharmacological and toxicological aspects

Ferulic acid (FA) belongs to the family of phenolic acids and is very abundant in fruits and vegetables. Over the past years, several studies have shown that FA acts as a potent antioxidant by scavenging free radicals and enhancing the cell stress response through the up-regulation of cytoprotective systems, e.g. heme oxygenase-1, heat shock protein 70, extracellular signal-regulated kinase 1/2 and the proto-oncogene Akt. Furthermore, FA was shown to inhibit the expression and/or activity of cytotoxic enzymes, including inducible nitric oxide synthase, caspases and cyclooxygenase-2. Based on this evidence, FA has been proposed as a potential treatment for many disorders including Alzheimer’s disease, cancer, cardiovascular diseases, diabetes mellitus and skin disease. However, despite the great abundance of preclinical research, only a few studies were carried out in humans, the majority of which used foods containing FA, and therefore the clinical efficacy of this mode of administration needs to be further documented. New efforts and resources are needed in clinical research for the complete evaluation of FA therapeutic potential in chronic diseases.