活体生物荧光成像技术检测HO-1在HO-1/Luc小鼠肝脏缺血模型中的表达

目的尝试使用活体生物荧光成像技术无创定量检测HO-1在活体动物肝脏温缺血模型中的时空表达。方法建立小鼠部分肝脏温缺血模型，使用活体生物荧光成像技术连续检测HO-1在HO-1／Luc转基因报告小鼠中的转录情况。使用RT-PCR方法检测HO-1 mRNA水平，免疫组织化学方法行HO-1的表达定位。结果缺血肝叶发出的荧光信号最早于再灌注后3h被检测到，随后信号不断增强在9h达到峰值，然后信号逐渐减弱至再灌注后48h恢复至基础水平。RT-PCR方法测得在HO-1蛋白上调之前出现了HO-1mRNA的表达增强。免疫组织化学染色方法证实肝脏细胞是缺血再灌注损伤后HO-1表达上调的主要部位。结论活体生物荧光成像技术可以实时定量检测肝脏缺血后HO-1的表达，是一项敏感的检测技术。     

Absence of heme oxygenase-1 exacerbates myocardial ischemia/reperfusion injury in diabetic mice

Increased production of reactive oxygen species contributes to the etiology of diabetes complications. Pathophysiological stimuli that increase oxidative stress upregulate heme oxygenase (HO)-1, a cytoprotective heme-degrading enzyme. We hypothesized that HO-1 may be important in myocardial injury that is exacerbated by diabetes. To test this hypothesis, the left anterior descending coronary arteries of nondiabetic and diabetic wild-type (HO-1(+/+)) and HO-1 null (HO-1(-/-)) mice were ligated for 1 h followed by 24 h reperfusion. The absence of HO-1 significantly increased myocardial infarct size (36.4 +/- 2.0 vs. 21.4 +/- 1.8% in HO-1(+/+) mice), while cardiac-specific overexpression of HO-1 protected against myocardial ischemic injury in diabetic mice. Despite similar high blood glucose levels, diabetic HO-1(-/-) mice had fourfold higher oxidative stress and larger infarcts (56.0 +/- 2.8%) than diabetic HO-1(+/+) mice (30.8 +/- 6.1%). Moreover, hyperglycemia increased the mortality of HO-1(-/-) mice (31.3%) after ischemia/reperfusion injury, and 55% of diabetic HO-1(-/-) mice had mural thrombi in the left ventricles. The increased mortality of diabetic HO-1(-/-) mice may be in part due to formation of left ventricular mural thrombi. Our data demonstrate that the absence of HO-1 renders animals more susceptible to myocardial ischemia/reperfusion damage and diabetes worsens the injury.     

Mechanism of hepatic heme oxygenase-1 induction by isoflurane

BACKGROUND: The heme oxygenase pathway represents a major cell and organ protective system in the liver. The authors recently showed that isoflurane and sevoflurane up-regulate the inducible isoform heme oxygenase 1 (HO-1). Because the activating cascade remained unclear, it was the aim of this study to identify the underlying mechanism of this effect. METHODS: Rats were anesthetized with pentobarbital intravenously or with isoflurane per inhalation (2.3 vol%). Kupffer cell function was inhibited by dexamethasone or gadolinium chloride. Nitric oxide synthases were inhibited by either N(omega)-nitro-L-arginine methyl ester or S-methyl thiourea. N-acetyl-cysteine served as an antioxidant, and diethyldithiocarbamate served as an inhibitor of cytochrome P450 2E1. Protein kinase C and phospholipase A2 were inhibited by chelerythrine or quinacrine, respectively. HO-1 was analyzed in liver tissue by Northern blot, Western blot, immunostaining, and enzymatic activity assay. RESULTS: In contrast to pentobarbital, isoflurane induced HO-1 after 4-6 h in hepatocytes in the pericentral region of the liver. The induction was prevented in the presence of dexamethasone (P < 0.05) and gadolinium chloride (P < 0.05). Inhibition of nitric oxide synthases or reactive oxygen intermediates did not affect isoflurane-mediated HO-1 up-regulation. In contrast, chelerythrine (P < 0.05) and quinacrine (P < 0.05) resulted in a blockade of HO-1 induction. CONCLUSION: The up-regulation of HO-1 by isoflurane in the liver is restricted to parenchymal cells and depends on Kupffer cell function. The induction is independent of nitric oxide or reactive oxygen species but does involve protein kinase C and phospholipase A2.     

Systemic expression of heme oxygenase-1 ameliorates type 1 diabetes in NOD mice

Heme oxygenase-1 (HO-1) is an enzyme with potent immunoregulatory capacity. To evaluate the effect of HO-1 on autoimmune diabetes, female NOD mice at 9 weeks of age received a single intravenous injection of a recombinant adeno-associated virus bearing HO-1 gene (AAV-HO-1; 0.5 x 10(10)-2.5 x 10(10) viruses/mouse). In a dose-dependent manner, HO-1 transduction reduced destructive insulitis and the incidence of overt diabetes examined over a 15-week period. HO-1-mediated protection was associated with a lower type 1 T-helper cell (Th1)-mediated response. Adaptive transfer experiments in NOD.scid mice demonstrated that splenocytes isolated from AAV-HO-1-treated mice were less diabetogenic. Flow cytometry analysis revealed no significant difference in the percentages of CD4(+)CD25(+) regulatory T-cells between saline-treated and AAV-HO-1-treated groups. However, the CD11c(+) major histocompatibility complex II(+) dendritic cell population was much lower in the AAV-HO-1-treated group. A similar protective effect against diabetes was observed in NOD mice subjected to carbon monoxide (CO) gas (250 ppm CO for 2 h, twice per week). These data suggest that HO-1 slows the progression to overt diabetes in pre-diabetic NOD mice by downregulating the phenotypic maturity of dendritic cells and Th1 effector function. CO appears to mediate at least partly the beneficial effect of HO-1 in this disease setting.     

血红素加氧酶-1在心脏移植急性排斥反应中的表达及意义

目的 探讨血红素加氧酶-1(HO-1)在心脏移植急性排斥反应中的表达及意义。方法建立小鼠颈部异位心脏移植模型。实验分为同系移植组(C57BL／6小鼠→C57BL／6小鼠)和同种移植组(BAILB／c小鼠→C57BL／6小鼠)。免疫组织化学和RT-PCR方法观察HO-1在心肌组织的表达；普鲁士兰染色法观察铁在心肌组织的沉积情况。结果 HO1主要在浸润的炎性细胞中表达，铁在浸润的巨噬细胞中表达，二者随急性排斥反应的加重表达上调。结论 HO-1参与了心脏移植急性排斥反应的病理过程；HO-1在炎性细胞的过表达，可作为心脏移植急性排斥反应的监测指标。     

血红素氧合酶-1对大鼠肾缺血再灌注损伤的保护作用

目的　探讨钴卟啉 (CoPP)诱导的血红素氧合酶 (HO) 1高表达对大鼠肾缺血再灌注损伤 (IRI)的保护作用。方法　建立大鼠肾缺血再灌注损伤模型 ,随机将动物分为假手术组 ,对照组和实验组。动态检测血尿素氮 (BUN)、肌酐 (Cr)、超氧化物岐化酶 (SOD)、丙二醛 (MDA)的含量以及进行肾组织光镜形态学观察和酶联免疫吸附试验 (ELISA)和Westernblot分析HO 1。结果　对照组BUN、Cr升高 ,SOD下降 ,MDA升高 ,HO 1中度提高 (14 4.5± 13 .6) ,肾组织结构紊乱。实验组除HO 1含量大幅提高外 (62 9.4± 78.9) ,尚能显著逆转上述改变 ,两组间差异具有统计学意义 (P <0 .0 5 )。结论　CoPP预处理诱导HO 1在肾缺血之前高表达可通过清除氧自由基 (OFRs)而减轻大鼠肾IRI。     

Increased expression of heme oxygenase-1 in human lung transplantation.

Heme oxygenase-1 (HO-1) has been found to be a cytoprotective protein, and has recently been identified as a graft survival gene. This study demonstrates that HO-1 expression is increased in human lung allografts with acute cellular rejection and obliterative bronchiolitis. HO-1 expression was correlated with increased tissue iron and/or ferritin expression and increased inflammatory/oxidant load as measured by myeloperoxidase expression. Although the trigger for increased HO-1 expression in this setting is unknown, it may be related to hemorrhage and/or oxidative stress associated with rejection.     

血红素加氧酶-1(HO-1)基因转染治疗急性胰腺炎的研究展望

血红素加氧酶-1(heme oxygenase-1,HO-1)通过分解血红素产生一氧化碳、胆绿素、胆红素及亚铁离子,可以减轻炎性介质反应,拮抗细胞氧化损伤和细胞应激从而发挥细胞保护作用.基因转染的方法能够维持目的基因的长时间表达,可以调节细胞因子的免疫反应.HO-1基因转染已在其他疾病的治疗研究中取得良好成果,本文针对...     

Hypothermia protects against gut ischemia/reperfusion-induced impaired intestinal transit by inducing heme oxygenase-1

PURPOSE: Gut ischemia/reperfusion (I/R) elicits an inflammatory response that impairs intestinal transit. We have previously shown that regional intraischemic hypothermia (IH) protects against moderate gut I/R-induced mucosal injury, is associated with decreased NF-kappaB activity and inducible nitric oxide synthase induction and preserves heme oxygenase-1 (HO-1) expression. HO-1 provides cytoprotection in various models of oxidant stress. We, therefore, tested the hypothesis that IH protects against gut I/R-induced impaired intestinal transit via HO-1 induction. MATERIALS AND METHODS: At laparotomy (lap), Sprague-Dawley rats had duodenal catheters placed followed by sham or gut I/R (superior mesenteric artery occlusion for 75 min) with or without regional IH (15 degrees C). Each animal was placed on a heating blanket maintaining systemic normothermia (37 degrees C). At 12 or 24 h of reperfusion, small intestinal transit was determined by quantitating the distribution of a tracer (FITC dextran) in the intestine 30 min after instillation (expressed as geometric center of distribution). Ileal samples were obtained for histology and HO-1 expression, assessed by Western immunoblot at 12 and 24 h of reperfusion. In separate experiments, rats were pretreated with an HO-1 inhibitor Sn protoporphyrin IX (25 mumol/kg, ip), 1 h before superior mesenteric artery occlusion and transit measured as above. RESULTS: Rats treated with I/R had increased histological injury and impaired intestinal transit at both 12 and 24 h compared with sham. Rats treated with I/R+IH exhibited histological injury and transit comparable with sham controls. I/R induced HO-1 expression at 12 and 24 h of reperfusion and IH augmented this I/R-induced HO-1 expression. Sn protoporphyrin IX abrogated IH protection against histological injury and impaired transit. CONCLUSION: We conclude that intraischemic regional hypothermia protects against histological injury and impaired intestinal transit caused by severe gut I/R injury. Hypothermic protection under these conditions is in part due to HO-1 expression.     

血红素加氧酶-1诱导对鼠肝缺血再灌注损伤的保护作用

目的研究血红素加氧酶-1(heme oxygenase-1,HO-1)在鼠肝缺血再灌注损伤肝组织中的表达及其作用。方法建立小鼠部分肝脏热缺血再灌注损伤模型,36只清洁级Balb/C小鼠随机分为3组: 假手术组(S组)、缺血/再灌注损伤组(I/R组)、HO-1诱导剂氯化高铁血红素(hemin)预处理组(HM组)。免疫组化半定量分析肝组织HO-1蛋白的表达,检测血清AST和ALT,肝组织丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性,并观察肝组织的病理变化。结果与S组比较,I/R组HO-1蛋白表达显著增强,hemin预处理后,HO-1蛋白表达较I/R组增高(P<0．01)。I/R组AST,ALT活性和MDA的含量显著高于S组,而HM组均显著低于I/R组(P<0．01);I/R组SOD活性下降,而HM组显著高于I/R组(P<0．01)。HM组病理损伤程度明显轻于I/R组。结论 HO-1在鼠肝缺血再灌注损伤肝组织中表达上调,对肝脏具有保护效应。     

HO-1 upregulation suppresses type 1 IFN pathway in hepatic ischemia/reperfusion injury

Upregulation of heme oxygenase (HO)-1, a heat shock protein 32, protects against hepatic ischemia/reperfusion (I/R) injury. Activation of "innate" toll-like receptor (TLR) 4 system triggers the I/R injury cascade. This study explores cytoprotective functions of HO-1 overexpression following exogenous administration of cobalt protoporphyrin (CoPP), and its relationship with the TLR4 pathway in a model of mouse partial hepatic warm I/R injury. CoPP treatment markedly improved hepatic function and histology, and suppressed pro-inflammatory cytokine elaboration profile, as compared with untreated controls. Although administration of CoPP did not affect intrahepatic TLR4, it downregulated IFN-inducible protein 10 (IP-10) expression. As IP-10 is the major product of type-1 IFN pathway downstream of TLR4, we then infused recombinant IFN-beta (rIFN-beta) directly into mouse livers. Interestingly, infusion of rIFN-beta upregulated hepatic IP-10 expression. In contrast, adjunctive CoPP treatment decreased IP-10 levels in mouse livers infused with rIFN-beta. Thus, CoPP-induced HO-1 upregulation suppresses type-1 IFN pathway downstream of TLR4 system in hepatic warm I/R injury model.     

细胞穿透肽PEP-1导入血红素加氧酶-1蛋白对大鼠肾缺血再灌注损伤的影响

目的 评价细胞穿透肽PEP-1导入血红素加氧酶-1(HO-1)蛋白对大鼠肾缺血再灌注损伤的影响.方法 健康雄性SD大鼠18只,周龄7～9周,体重210 ～ 260 g,采用随机数字表法,将其随机分为3组(n=6):假手术组(S组)、肾缺血再灌注组(I/R组)和融合蛋白PEP-1/HO-1+肾缺血再灌注组(HO组).采用夹闭双侧肾动脉45 min恢复灌注的方法制备大鼠肾缺血再灌注损伤模型.HO组于夹闭双侧肾动脉前30 min时静脉注射融合蛋白PEP-1/HO-1.于再灌注6h时取右侧颈总动脉血样,测定血清BUN和Cr浓度;取肾组织检测MDA含量和SOD活性;采用免疫组化法检测肾组织HO-1的表达.结果 与S组比较,I/R组和HO组肾组织MDA含量、血清BUN和Cr浓度升高,肾组织SOD活性降低,HO-1蛋白表达上调(P＜0.05);与I/R组比较,HO组肾组织MDA含量、血清BUN和Cr浓度降低,肾组织SOD活性升高,HO-1蛋白表达上调(P＜0.05).结论 细胞穿透肽PEP-1将HO-1蛋白成功导入肾组织,导入的HO-1蛋白通过抑制脂质过氧化反应减轻肾缺血再灌注损伤.     

Assessment of heme oxygenase-1 （HO-1） activity in the cavernous tissues of sildenafil citrate-treated rats

Aim： To assess heine oxygenase-1 （HO-1） activity in the cavemous tissue of sildenafil citrate-treated rats. Methods： One hundred and ninety-two Sprague-Dawley male rats, divided into four equal groups, were investigated. Group 1, the control group, received regular animal chow; group 2 received sildenafil citrate by intragastric tube; group 3 received sildenafil and HO inhibitor （zinc protoporphyrin, ZnPP）; and group 4 received sildenafil and nitric oxide synthase （NOS） inhibitor L-nitroarginine methyl ester （L-NAME）. Twelve rats from each group were killed after 0.5 h, 1 h, 2 h and 3 h of drug administration. Then HO-1 activity, cGMP levels and NOS enzymatic activity in the cavernous tissues were estimated. Results： In cavemous tissue, HO-1 activity, NOS enzymatic activity and cGMP concentration increased significantly in sildenafil-treated rats compared to other groups throughout the experiment. Rats receiving either HO or NOS inhibitors showed a significant decrease in these parameters. HO- 1 cavemous tissue activity and NOS enzymatic activity demonstrated a positive significant correlation with cGMP levels （r = 0.646, r = 0.612 respectively; P 〈 0.001）. Conclusion： The actions of PDE5 inhibitor sildenafil citrate in the cavernous tissue are partly mediated through the interdependent relationship between both HO-1 and NOS activities.     

Induction of heme oxygenase-1 in kidneys during ex vivo warm perfusion

BACKGROUND: Reperfusion injury plays a pivotal role in the occurrence of delayed graft function and chronic rejection. Heme oxygenase-1 (HO-1), an inducible heat shock protein, is known to have cytoprotective effects against reperfusion injury. We report on the potential for ex vivo induction of HO-1 expression during acellular warm perfusion of canine kidneys, using cobalt protoporphyrin (CoPP) as an HO-1 inducer and zinc protoporphyrin as an HO-1 inhibitor. METHODS: Canine kidneys were used to evaluate HO-1 increase after exposure to warm ischemia (WI), hypothermic perfusion (mechanical perfusion [MP], 4 degrees C), warm perfusion (exsanguineous metabolic support [EMS], 32 degrees C), or various combinations. RESULTS: WI alone, MP, or EMS with or without WI, had no effect on HO-1 activity. However, the presence of CoPP during EMS perfusion resulted in a significant increase in kidney HO-1 activity, whereas zinc protoporphyrin reduced HO-1 activity. The presence of CoPP during MP did not induce elevated HO-1 expression. The results of our study demonstrate that sufficient metabolism supporting new protein synthesis resulting in the expression of the protective gene, HO-1, can be accomplished during an acellular near-normothermic perfusion using CoPP. Most importantly, the time required for ex vivo HO-1 induction with this method is compatible with the current time frame for which organs are preserved clinically.CONCLUSIONS: The ability to induce HO-1 expression ex vivo eliminates the need for donor therapy to induce HO-1 increase before retrieving organs and also prevents the potential of decreasing HO-1 enzyme activity that is known to occur with temperature-mediated inhibition of oxidative metabolism during hypothermic organ storage.     

Change and role of heme oxygenase-1 in injured lungs following limb ischemia／reperfusion in rats

Lowerlimbischemiafollowedbyreperfusionisanimportantandcommonclinicalevent .Bothclinicalobservationandanimalexperimentindicatethatrestorationofbloodflowcansavethelimbsbutresultsinmultisystemorgandysfunctionevendeath .1Althoughthesystemicinflammationoflimbischemia/reperfusion (I/R )candamageanyorgan ,theonsetofthesyndromeisusuallyheraldedbythedevelopmentof pulmonarydysfunction .2 ,3Thiskindofpulmonarydysfunctionischaracterizedbyincreasedlungvascular permeabilityandpulmonaryhypertension ,whichis…