血红素加氧酶-1对肝癌细胞细胞周期调控因子的影响

目的 观察血红素加氧酶-1(heme oxygenase 1,HO-1)对人肝癌细胞HepG2细胞周期调控因子的影响.方法 构建含有野生型和突变型HO-1基因的重组载体pcDNA3.1(+)-wtHO-1和pcDNA3.1(+)-mHO-1G143H.利用脂质体介导的方法将构建好的重组载体转染肝癌细胞系HepG2,以空载体转染作为对照组.通过G418筛选建立稳定表达野生型和突变型HO-1的HepG2肝癌细胞系.经半定量RT-PCR、Western印迹检测转染细胞系中HO-1 mRNA和蛋白的表达水平.在HO-1表达改变的稳转细胞系中,利用Western 印迹检测转染细胞系中P21、P27蛋白表达水平.结果 成功实现了野生型和突变型HO-1在HepG2细胞中的过表达;野生型和突变型HO-1过表达均能诱导抑癌基因p21和p27的表达.结论 HO-1过表达诱导抑癌基因p21和p27的表达与血红素分解产物无关.HO-1可能通过其它机制调节p21和p27的表达.     

α-硫辛酸对帕金森病大鼠脑内黑质多巴胺能神经元保护机制研究

目的 探讨α-硫辛酸(LA)对帕金森病(PD)大鼠模型脑内黑质多巴胺能神经元的保护机制.方法 60只3月龄雄性Wistar大鼠随机分为对照组、实验组和药物干预组,每组20只.对照组大鼠给予背部皮下注射葵花油,实验组和药物干预组背部皮下注射鱼藤酮制备PD模型,药物干预组大鼠同时给予LA腹腔注射;采用Western blot检测大鼠中脑多巴胺能神经元中酪氨酸羟化酶(TH)、转录因子NF-E2相关因子-抗氧化反应元件(Nrf2-ARE)和血红素氧合酶1(HO-1)的表达变化;采用分光光度法检测大鼠脑内纹状体中丙二醛(MDA)和还原型谷胱甘肽(GSH)含量变化.结果 实验组大鼠中脑TH蛋白表达比对照组明显降低(P<0.05);药物干预组中脑TH蛋白在黑质比鱼藤酮组明显增高(P<0.05),但是较对照组仍有明显减少(P<0.05).实验组大鼠Nrf2和HO-1蛋白表达比对照组明显降低(P<0.05);药物干预组Nrf2和HO-1蛋白表达比实验组明显增高(P<0.05),但是较对照组仍有明显降低(P<0.05).与对照组相比,实验组大鼠纹状体组织中脂质代谢产物MDA含量明显增加(P<0.01),药物干预后纹状体中MDA含量明显减少(P<0.05),但较对照组仍明显增高(P<0.05).与对照组相比,实验组大鼠GSH的含量明显减少(P<0.01),药物干预后GSH明显增加(P<0.05),但较对照组仍显著降低(P<0.05).结论 LA能激活Nrf2-ARE信号通路对PD大鼠模型中脑多巴胺能神经元起到有效的神经保护作用,改善PD样症状.     

Curcumin ameliorates hepatic chronic inflammation induced by bile duct obstruction in mice through the activation of heme oxygenase-1

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Dynamic Change of Heme Environment in Soluble Guanylate Cyclase and Complexation of NO‐Independent Drug Agents with H‐NOX Domain

Soluble guanylate cyclase is a heterodimer receptor that functions in several signal transduction pathways. Conversion of guanosine 5′‐triphosphate to 3′,5′‐cyclic monophosphate second messenger at the catalytic domain is regulated by the changes at heme nitric oxide/oxygen domain of the β‐subunit. To better understand conformational changes at heme site that may impact on activities of catalytic domain, three soluble guanylate cyclase homolog proteins with heme at Fe‐His state were investigated, and their dynamic behaviors were monitored in both unliganded (apo) and complex with heme. As a result of dynamic conformational changes, Lys110, Asp45, Arg135, and Glu41 were found interacting with the site gate, which may interfere with transportation of small molecules in and out of the heme site. An alternative binding site adjacent to that of heme was identified. Binding affinity of several nitric oxide‐independent activators and heme‐dependent stimulators was examined, and their binding modes in the heme site and in the alternative binding site in the human soluble guanylate cyclase enzyme were computationally simulated. The calculated binding energies were used as criteria to filter results of virtual high‐throughput screenings based on FlexX ligand–docking algorithm and absorption, distribution, metabolism, excretion, and toxicity properties on databases of available drugs. The identified drugs from virtual high‐throughput screening have been suggested for experimental investigations, based on which they may either be directly repurposed or require structural modifications for better physico‐chemical and pharmacological properties.     

血红素氧合酶-1与视网膜

血红素氧合酶(heme oxygenase,HO)是体内唯一一种催化血红素分解代谢的限速酶,他可以氧化降解血红素,将其分解为一氧化碳、自由铁和胆绿素。其中诱导型血红素氧合酶-血红素氧合酶-1(HO-1)是机体最重要的内源性保护物质之一,广泛参与组织细胞的抗氧化应激损伤,被认为是在细胞受损维持其氧化和抗氧化动态平衡的关键因素,本文就HO-l与视网膜的关系作如下综述。     

基于Nrf2/HO-1通路的中医药干预溃疡性结肠炎研究进展

溃疡性结肠炎（UC）是临床常见的一种慢性消化系统疾病,其病情反复且治疗难度大,发病机制复杂,与氧化应激反应相关。核转录因子E₂相关因子2（Nrf2）是抗氧化反应中的重要因子,可调控其下游血红素加氧-1（HO-1）的表达,发挥维持机体氧化还原稳态的作用。UC的病程中Nrf2与HO-1的生物活性及含量水平均下降,组织抗氧化和抗炎能力减弱,肠上皮细胞损伤,肠黏膜屏障破坏。目前西医临床上主要以控制炎症和缓解症状治疗为主,虽有一定疗效,但存在停药后易复发、长期用药不良反应多等问题。研究表明,中医药治疗手段丰富,治疗方法灵活,在UC的防治上有广阔的应用前景。近年来,以Nrf2/HO-1通路为切入点,中医药领域开展了大量关于UC中该信号的基础和临床实验,结果表明Nrf2/HO-1通路是中医药治疗UC的重要潜在靶点。基于虚实夹杂的病因病机,中医药以清热解毒燥湿、活血化瘀止痛、益气补中温里和标本兼治等法调控Nrf2/HO-1通路,提高组织抗氧化应激能力,维持促炎因子与抗炎因子平衡,缓解炎症反应,发挥对UC的治疗作用。该文总结和分析了中医药靶向Nrf2/HO-1信号通路干预UC的机制和作用,以期为科研人员更为全面认识中医药对UC中Nrf2/HO-1通路的作用机制提供帮助,旨在推动今后中医药合理运用于临床UC的防治。     

Iron Metabolism Genes,Low-Level Lead Exposure,and QT Interval

Background

Cumulative exposure to lead has been shown to be associated with depression of electrocardiographic conduction, such as QT interval (time from start of the Q wave to end of the T wave). Because iron can enhance the oxidative effects of lead, we examined whether polymorphisms in iron metabolism genes [hemochromatosis (HFE), transferrin (TF) C2, and heme oxygenase-1 (HMOX-1)] increase susceptibility to the effects of lead on QT interval in 613 community-dwelling older men.

Methods

We used standard 12-lead electrocardiograms, K-shell X-ray fluorescence, and graphite furnace atomic absorption spectrometry to measure QT interval, bone lead, and blood lead levels, respectively.

Results

A one-interquartile-range increase in tibia lead level (13 μg/g) was associated with a 11.35-msec [95% confidence interval (CI), 4.05–18.65 msec] and a 6.81-msec (95% CI, 1.67–11.95 msec) increase in the heart-rate–corrected QT interval among persons carrying long HMOX-1 alleles and at least one copy of an HFE variant, respectively, but had no effect in persons with short and middle HMOX-1 alleles and the wild-type HFE genotype. The lengthening of the heart-rate–corrected QT interval with higher tibia lead and blood lead became more pronounced as the total number (0 vs. 1 vs. ≥2) of gene variants increased (tibia, p-trend = 0.01; blood, p-trend = 0.04). This synergy seems to be driven by a joint effect between HFE variant and HMOX-1 L alleles.

Conclusion

We found evidence that gene variants related to iron metabolism increase the impacts of low-level lead exposure on the prolonged QT interval. This is the first such report, so these results should be interpreted cautiously and need to be independently verified.     

辛伐他汀和氨氯地平对实验性兔动脉粥样硬化进程中HO／CO系统的影响

目的探讨血红素加氧酶．一氧化碳系统在动脉粥样硬化中的变化、相互关系及辛伐他汀、氨氯地平对动脉粥样硬化进程中血红素加氧酶-一氧化碳的影响。方法家兔予以高胆固醇饮食（n=24）18周,8周后改用普通饮食并随机分为三组,模型组停用高胆固醇饮食,改普通饮食（n=8）;辛伐他汀组给予喂饲辛伐他汀进行药物干预8周,氨氯地平组给予喂饲氨氯地平进行药物干预8周（n=8）。同时设正常对照组（n=8）：给予普通饲料喂养16周。然后取静脉血分别用Chalmers A．H、硝酸还原酶法测定各实验组血中CO,取主动脉组织用免疫组织化学方法测定主动脉组织中HO-1的表达;并比较组间各项参数的差异。结果16周末模型组血脂水平、血浆一氧化碳水平、血红素加氧酶-1表达较对照组明显升高。辛伐他汀组血浆TC、TG、LDL下降明显,HDL升高;血浆一氧化碳水平及血红素加氧酶-1表达均明显降低。而氨氯地平组血脂无明显变化;血浆一氧化碳水平、血红素加氧酶-1表达亦明显降低。结论动脉粥样硬化进程中,辛伐他汀、氨氯地平均可以通过下调血红素加氧酶／一氧化碳系统而延缓动脉粥样硬化进程。     

异丙酚和咪唑安定对发绀型心脏病患儿心内直视手术心肌AngⅡ和HO-1的影响

目的观察比较异丙酚和咪唑安定对发绀型心脏病患儿心内直视手术的心肌保护作用及机制。方法选择ASAⅠ～Ⅱ级行心内直视手术的发绀型心脏病患儿32例,随机分为异丙酚复合小剂量芬太尼组(PF组,n=16)和咪唑安定复合小剂量芬太尼组(MF组,n=16)。观察患儿血流动力学变化,检测开放静脉通路时(T0)、主动脉开放后2 h(T3)、术后24 h(T4)的静脉血血浆中肌钙蛋白I(cTnI)含量。检测主动脉阻断后10～20 min(T1)和主动脉开放后10～20 min(T2)时的心肌组织血管紧张素Ⅱ(AngⅡ)含量和血红素加氧酶-1(HO-1)的表达。结果 2组患儿围手术期血流动力学和同时点血cTnI水平无显著性差异;2组患儿T2时点心肌中AngⅡ含量均高于T1时点水平,T2时点心肌中AngⅡ含量PF组高于MF组(P<0.05);2组心肌HO-1表达T2时点均高于T1时点(P均<0.01),PF组同时点HO-1表达均高于MF组(P均<0.05)。结论异丙酚和咪唑安定对发绀型心脏病患儿体外循环心内直视手术心肌保护作用相当,咪唑安定抑制心肌AngⅡ表达的作用比异丙酚强,而异丙酚刺激心肌HO-1表达的作用优于咪唑安定。