Spotlights on immunological effects of reactive nitrogen species: When inflammation says nitric oxide

Over the last decades, nitric oxide(NO) has been definitively recognised as one of the key players involved in immunity and inflammation. NO generation was originally described in activated macrophages, which still represent the prototype of NO-producing cells. Notwithstanding, additional cell subsets belonging to both innate and adaptive immunity have been documented to sustain NO propagation by means of the enzymatic activity of different nitric oxide synthase isoforms. Furthermore, due to its chemical characteristics, NO could rapidly react with other free radicals to generate different reactive nitrogen species(RNS), which have been intriguingly associated with many pathological conditions. Nonetheless, the plethora of NO/RNS-mediated effects still remains extremely puzzling. The aim of this manuscript is to dig into the broad literature on the topic to provide intriguing insights on NO-mediated circuits within immune system. We analysed NO and RNS immunological clues arising from their biochemical properties, immunomodulatory activities and finally dealing with their impact on different pathological scenarios with far prompting intriguing perspectives for their pharmacological targeting.

Comparison of Mechanisms of N-Nitrosation and N-Nitration of Ammonia and Dimethylamine by Reactive Nitrogen Oxygen Species:A Theoretical Study

Reactive nitrogen oxygen species（RNOS） implicate damage in biological systems,especially leading to inflammation,neurodegenerative and cardiovascular diseases,and cancer by altering the functions of biomolecules through the N-nitrosation and N-nitration reactions.The mechanisms of N-nitrosation and N-nitration reactions of ammonia and dimethylamine by RNOS,i.e.,N2O3,N2O4,N2O5 and ONOOH,were investigated at the CBS-QB3 level of theory.The computational results indicate that the N-nitrosation reaction prefers a concerted mechanism,in which a H-abstraction and ON-addition occur simultaneously,whereas a stepwise mechanism（also called a free radical mechanism） is more favorable for most nitrating agents in the N-nitration reaction,where NO2 first abstracts a hydrogen atom from the nitrogen of amines and then the induced intermediate reacts with NO2 once more to form the nitration products.However,the concerted pathway is still a feasible process for some nitrating agents such as N2O5.In addition,the relationship between the structures of different RNOS and their nitrosating or nitrating abilities was also investigated.

Role of Active Principles of Podophyllum hexandrum in Amelioration of Radiation Mediated Lung Injuries by Reactive Oxygen/Nitrogen Species Reduction

Radiation induced reactive oxygen/nitrogen species (ROS/RNS) are reported to cause lung injuries such as pneumonitis and fibrosis which may be fatal at times. Current study is designed to analyse the radioprotective efficacy of P. hexandrum active principles (G-002M) on lungs of mice exposed to high dose of gamma irradiation (7 Gy). Cellular profiles and inflammatory cell infiltrates of irradiated bronchoalveolar lavage fluid (BALF) have shown correlations with lung pathology. Cell counts were determined in BALF of control, 7 Gy radiation exposed and radiation with G-002M pretreated mice. ROS/Nitric Oxide (NO) production was measured by 2,7?dichlorodihydrofluorescein diacetate (DCF-DA) and diaminofluorescein diacetate (DAF-2DA) through microscopy and flow cytometry respectively. Immunostaining of inducible nitric oxide synthase (iNOS) in BALF cells and lung sections was also observed microscopically. iNOS ex- pression was observed in lungs by western blotting. BALF was also processed to estimate total protein, LDH, and phospholipids content. Catalase, reduced Glutathione (GSH), Glutathione reductase (GR) and lipid peroxidation were estimated in lung tissues. Pre-administration of G-002M significantly decreased radiation mediated neutrophils count in BALF of irradiated mice. ROS generation, iNOS expression, total protein, LDH and phospholipids were found less affected in G-002M pretreated group in comparison to radiation alone group. Radiation exposure to mice was found apparently leading to parenchymal fibrosis, an architectural distortion of the lung tissue with edema, infiltration of inflammatory blood cells with increased immunolabeling of iNOS. G-002M pretreatment significantly countered radiation mediated increased lipid peroxidation and decreased GR, catalase and GSH in mice. Current study demonstrates possible role of P. hexandrum (G-002M) in minimizing lung damage induced by radiation mediated ROS/RNS generation.

Study on the protective effect of Tadehaginoside on the damage of endothelial cell mitochondria induced by reactive nitrogen

Objective:To investigate the protective effect of Tadehaginoside on vascular endothelial cell injury induced by reactive nitrogen.Methods:MTT colorimetry was used to detect the effect of Tadehaginoside on the survival rate of EA.hy 926 endothelial cells in the concentration range of 5~160μmol/L;1 h after pre-administration of Tadehaginoside,0.5 mM GSNO was given to damage endothelial cells.Detect the mitochondrial specific factors COX-1,ND-1 and inflammatory factor IL-1βof EA.hy 926 cells damaged by GSNO by Real time-PCR method gene intervention.At the same time,Western blot was used to detect the changes in Bax and Bcl-2 protein expression.The mitochondrial membrane potential kit(JC-1)was used to detect the change of Tadehaginoside on the mitochondrial membrane potential after GSNO induced EA.hy 926 cell injury.Results:The results of the MTT method showed that Tadehaginoside had no obvious cytotoxicity on EA.hy 926 cells in the range of 5~160μmol/L,and the optimal protective concentration of the drug was 40μmol/L.Western Blot method showed that BAX protein expression increased in a time-dependent manner after GSNO damaged EA.hy 926 cells over time,while Bcl-2 protein expression was the opposite.Real time-PCR results showed that Tadehaginoside can significantly up-regulate COX-1 gene(P<0.05),and can significantly inhibit GSNO induced ND-1(P<0.05)and IL-1βgene up-regulation(P<0.01).At the same time,the results of JC-1 showed that Tadehaginoside could significantly protect the mitochondrial membrane potential from GSNO damage.Conclusion:The GSNO damage model may induce the increase of Bax and other pro-apoptotic proteins through mitochondrial DNA damage and reduce the expression of anti-apoptotic factor Bcl-2.Tadehaginoside has a certain protective effect on endothelial cell mitochondrial damage induced by reactive nitrogen,and its mechanism is related to inhibiting the expression of ND-1 and IL-1βgenes and upregulating the expression of COX-1 genes.

MEASUREMENTS OF REACTIVE NITROGEN SPECIES IN THE EASTERN CHINA DURING THE EXPERIMENT PEM-WEST A

Measurements of NO_x(NO+NO_2),HNO_3,particulate nitrate,and total odd nitrogen NO_y were made at Lin atmosphere regional background station during the NASA GTE/PEM-WEST A in the fall of 1991.NO_x and N were measured using chemiluminescence detectors.HNO_3 and aerosol nitrate(NO_3^-)were collected by a filter syst NO_x concentration exhibits a significant diurnal variation:maximum occurring in the evening and postsunrise w peak occurring following sunrise.Unlike NO_x,NO_y does not show distinct diurnal variations.From the ratios day/night NO_x concentration and the diurnal cycles of two kinds of weather conditions,it is clear that photochemical production of NO_x varies with solar radiation.NO_x is the major component of total odd nitro NO_y and NO_2 is the major portion of NO_x as well.The regional background concentrations of NO_x,NO_y,aerosol trate(NO_3^-)and HNO_3 range from 4.77 to 7.02 ppb,9.24 to 10.95 ppb,0.33 to 2.38 ppb and 0.31 to 0.97 ppb in a day average,respectively.In the eastern China,the biomass burning is an important local emission source of nitro species.The ratios of NO/NO_2,NO_x/NO_y,HNO_3/NO_y,NO_3^-/NO_y and HNO_3/NO_x are also discussed in paper.

硝化应激在肺动脉高压中的研究进展

肺动脉高压(pulmonary hypertension,PH)是一种进行性发展的肺血管疾病,病理基础包括内皮功能障碍、平滑肌细胞异常增生、炎症浸润以及肺纤维化。PH的发生机制尚不完全清楚,但硝化应激已经证实在PH中发挥了重要作用。该文综述了活性氮(reactive nitrogen species,RNS)的种类及肺循环中RNS的来源,以及由此引发的硝化应激在PH发生发展中的作用,以期为靶向抗硝化治疗的临床应用提供参考依据。

Scavenging of reactive oxygen and nitrogen species with nanomaterials

Reactive oxygen and nitrogen species （RONS） are essential for normal physiological processes and play important roles in cell signaling, immunity, and tissue homeostasis. However, excess radical species are implicated in the development and augmented pathogenesis of various diseases. Several antioxidants may restore the chemical balance, but their use is limited by disappointing results of clinical trials. Nanoparticles are an attractive therapeutic alternative because they can change the biodistribution profile of antioxidants, and possess intrinsic ability to scavenge RONS. Herein, we review the types of RONS, how they are implicated in several diseases, and the types of nanoparticles with inherent antioxidant capability, their mechanisms of action, and their biological applications.

Effects of nitrogen dioxide and its acid mist on reactive oxygen species production and antioxidant enzyme activity in Arabidopsis plants

Nitrogen dioxide（NO2） is one of the most common and harmful air pollutants. To analyze the response of plants to NO2 stress, we investigated the morphological change, reactive oxygen species（ROS） production and antioxidant enzyme activity in Arabidopsis thaliana（Col-0） exposed to 1.7, 4, 8.5, and 18.8 mg/m3NO2. The results indicate that NO2 exposure affected plant growth and chlorophyll（Chl） content, and increased oxygen free radical（O2-）production rate in Arabidopsis shoots. Furthermore, NO2 elevated the levels of lipid peroxidation and protein oxidation, accompanied by the induction of antioxidant enzyme activities and change of ascorbate（As A） and glutathione（GSH） contents. Following this, we mimicked nitric acid mist under experimental conditions, and confirmed the antioxidant mechanism of the plant to the stress. Our results imply that NO2 and its acid mist caused pollution risk to plant systems. During the process, increased ROS acted as a signal to induce a defense response, and antioxidant status played an important role in plant protection against NO2/nitric acid mist-caused oxidative damage.

Injectable reactive oxygen and nitrogen species-controlling hydrogels for tissue regeneration:current status and future perspectives

The dual role of reactive oxygen and nitrogen species(RONS)in physiological and pathological processes in biological systems has been widely reported.It has been recently suggested that the regulation of RONS levels under physiological and pathological conditions is a potential therapy to promote health and treat diseases,respectively.Injectable hydrogels have been emerging as promising biomaterials for RONS-related biomedical applications owing to their excellent biocompatibility,three-dimensional and extracellular matrix-mimicking structures,tunable properties and easy functionalization.These hydrogels have been developed as advanced injectable platforms for locally generating or scavenging RONS,depending on the specific conditions of the target disease.In this review article,the design principles and mechanism by which RONS are generated/scavenged from hydrogels are outlined alongside a discussion of their in vitro and in vivo evaluations.Additionally,we highlight the advantages and recent developments of these injectable RONS-controlling hydrogels for regenerativemedicines and tissue engineering applications.

Reactive oxygen and nitrogen species regulate porcine embryo development during pre-implantation period:A mini-review

Significant porcine embryonic loss occurs during conceptus morphological elongation and attachment from d 10 to 20 of pregnancy,which directly decreases the reproductive efficiency of sows.A successful establishment of pregnancy mainly depends on the endometrium receptivity,embryo quality,and utero-placental microenvironment,which requires complex cross-talk between the conceptus and uterus.The understanding of the molecular mechanism regulating the uterine-conceptus communication during porcine conceptus elongation and attachment has developed in the past decades.Reactive oxygen and nitrogen species,which are intracellular reactive metabolites that regulate cell fate decisions and alter their biological functions,have recently reportedly been involved in porcine conceptus elongation and attachment.This mini-review will mainly focus on the recent researches about the role of reactive ox-ygen and nitrogen species in regulating porcine embryo development during the pre-implantation period.

宰后成熟过程中活性氮与活性氧串扰对牦牛肉食用品质及微观结构的影响

为研究宰后成熟过程中活性氧(reactive oxygen species,ROS)与活性氮(reactive nitrogen species,RNS)串扰对牦牛肉食用品质及微观结构的影响。以经ROS促进剂、抑制剂与NO供体、一氧化氮合成酶抑制剂两两组合处理后的牦牛肉为研究对象,分析处理后成熟期间牦牛肉食用品质及微观结构的变化。结果显示,相比对照组,成熟期间同时激活ROS和RNS可显著增加牦牛肌肉的a^(*)值,而促进ROS的同时抑制RNS可显著降低L^(*)值和a^(*)值。同时,与对照组相比,激活ROS的同时促进或抑制RNS,牦牛肉pH值、剪切力、硬度和咀嚼性显著降低(P<0.05),而蒸煮损失、肌原纤维小片化指数(myofibrillar fragmentation index,MFI)和肌原纤维结构的断裂程度显著增加,利于肉的嫩化,这与抑制ROS的同时激活或抑制RNS对上述品质变化的影响相反。此外,高氧条件下,较RNS促进组相比,抑制RNS可显著降低牦牛肉的pH值、L^(*)值、a^(*)值、蒸煮损失、硬度、咀嚼性和剪切力值,而使MFI显著增大(P<0.05);低氧条件下,较RNS抑制组相比,激活RNS可显著增加牦牛肉pH值、a^(*)值、蒸煮损失和MFI,而使剪切力显著降低(P<0.05)。以上研究表明,抑制ROS条件下,激活或抑制RNS可阻碍肌肉的嫩化,而激活ROS的条件下激活或抑制RNS可有效改善牦牛肉的嫩度。综上,宰后ROS诱导蛋白氧化发生的同时抑制RNS可有效改善牦牛肉的嫩度。

硝基化修饰蛋白质在心血管内皮功能障碍中的作用

内皮功能障碍作为多种心血管疾病共同的特征之一,与过量表达的活性氧(ROS)/活性氮(RNS)密切相关。超氧阴离子与一氧化氮(NO)反应可以生成氧化能力更强的过氧亚硝酸盐,可以通过氧化多种蛋白质耗竭NO,导致内皮收缩与舒张功能障碍,在多种心血管疾病中发挥了重要的作用。该文通过综述硝基化修饰蛋白质产生的途径及其在心血管疾病中促进内皮功能紊乱的可能机制,讨论了ROS/RNS介导的硝基化修饰与内皮功能障碍之间相互促进,共同推动心血管疾病进程的关系。该文还讨论了清除过氧亚硝酸盐、抑制ROS产生途径以及直接增强内皮细胞功能的治疗策略在内皮功能障碍相关的心血管疾病中的应用,可以为进一步研究蛋白质硝基化修饰这一蛋白质翻译后修饰作为干预靶点在心血管疾病中的作用提供参考。

低温等离子体活化溶液在抑菌及清除生物被膜中的研究进展

细菌通过群体感应(QS)分泌信号分子和细胞外聚合物(EPS),使细菌聚集和黏附到生物和非生物表面,在一定条件下形成抗性强、危害性大的生物被膜。目前,生物被膜在医疗、食品和农业等领域中的危害日益严重。尤其是一些致病菌不仅对人类健康构成威胁,甚至会造成较大的社会经济损失。一些传统消毒、杀菌方法难以将其彻底清除,且存在二次污染风险。生物被膜在不同介质表面的强黏附性是其难以被清除的主要原因之一。因此,采用高活性的溶液进行浸泡、清洗是去除生物被膜的有效策略。低温等离子体活化水中的活性氧(ROS)和活性氮(RNS)能破坏细菌的细胞壁、肽聚糖结构,有效抑制微生物黏附和聚集。低温等离子体活化水作为一种高效消毒抑菌溶液,被广泛应用于生物医学、食品去污和种子萌发领域。但低温等离子体活化水中活性物质易消散,难以长期贮藏,导致其抑菌性能减弱。近年来,通过向低温等离子体活化水中添加不同介质或联合其他技术制备的低温等离子体活化溶液,有效延长了活性物质的衰退,使其逐渐成为消毒、抑菌研究的新方向。本文综述了低温等离子体活化水和低温等离子体活化溶液的杀菌作用机理及其对生物被膜的清除效果,重点介绍了生物被膜的形成过程。旨在为环境、医疗及食品行业的生物被膜清除和控制提供理论参考。

PAW及其与LTP的联合作用对小麦种子萌发及幼苗生长的影响

以济麦22、百农307为材料,研究等离子体活化水(PAW,制备时间分别为5.0、7.5、10.0 min,分别命名为PAW-5、PAW-7.5、PAW-10)及其与低温等离子体(LTP)联合处理(LTP+W-5、LTP+W-7.5、LTP+W-10)对小麦种子萌发及幼苗生长的影响,以期为PAW、LTP在小麦种子活力提高方面的应用提供理论依据。结果表明,2个小麦品种种子均于LTP处理9 s时的发芽率及发芽指数达到最佳,因此选用LTP处理时间9 s进行PAW与LTP联合作用效果研究。PAW、PAW与LTP联合处理均能提高小麦种子的发芽率、株高、幼苗鲜质量和干质量,并显著提高种子的活力指数,总体以LTP+W-7.5处理效果最好;未经LTP处理的种子与蒸馏水之间的接触角最大,表明其润湿性能最弱,相较之下,未经LTP处理的种子与PAW之间的接触角有所下降,而经LTP处理后的种子与蒸馏水或PAW之间的接触角极显著下降;与蒸馏水处理相比,PAW及其与LTP联合处理的小麦幼苗中的活性氧氮(RONS)含量总体上显著增加,而仅LTP处理的小麦幼苗中RONS含量无显著变化。综上,PAW及其与LTP联合处理均有效地促进了小麦种子萌发及幼苗生长,其中LTP+W-7.5处理的促进效果最佳。

Regulatory role of peroxynitrite in advanced glycation end products mediated diabetic cardiovascular complications

The Advanced Glycation End Products(AGE)binding with its receptor can increase reactive oxygen species(ROS)generation through specific signaling mediators.The effect of superoxide(O2-)and O2-mediated ROS and reactive nitrogen species depends on their concentration and location of formation.Nitric oxide(NO)has anti-inflammatory and anticoagulant properties and a vasodilation effect,but NO can be deactivated by reacting with O_(2)^(-).This reaction between NO and O2-produces the potent oxidant ONOO−.Therefore,ONOO-'s regulatory role in AGEs in diabetic cardiovascular complications must considered as a regulator of cardiovascular complications in diabetes.

H_2O_2-induced Leaf Cell Death and the Crosstalk of Reactive Nitric/Oxygen Species

In plants, the chloroplast is the main reactive oxygen species （ROS） producing site under high light stress. Catalase （CAT）, which decomposes hydrogen peroxide （H2O2）, is one of the controlling enzymes that maintains leaf redox homeostasis. The catalase mutants with reduced leaf catalase activity from different plant species exhibit an H2O2-induced leaf cell death phenotype. This phenotype was differently affected by light intensity or photoperiod, which may be caused by plant species, leaf redox status or growth conditions. In the rice CAT mutant nitric oxide excess 1 （noe1）, higher H2O2 levels induced the generation of nitric oxide （NO） and higher S-nitrosothiol （SNO） levels, suggesting that NO acts as an important endogenous mediator in H2O2-induced leaf cell death. As a free radical, NO could also react with other intracellular and extracellular targets and form a series of related molecules, collectively called reactive nitrogen species （RNS）. Recent studies have revealed that both RNS and ROS are important partners in plant leaf cell death. Here, we summarize the recent progress on H2O2-induced leaf cell death and the crosstalk of RNS and ROS signals in the plant hypersensitive response （HR）, leaf senescence, and other forms of leaf cell death triggered by diverse environmental conditions.

NIR-triggered on-site NO/ROS/RNS nanoreactor:Cascade-amplified photodynamic/photothermal therapy with local and systemic immune responses activation

Photothermal and photodynamic therapies(PTT/PDT)hold promise for localized tumor treatment,yet their full potential is hampered by limitations such as the hypoxic tumor microenvironment and inadequate systemic immune activation.Addressing these challenges,we present a novel near-infrared(NIR)-triggered RNS nanoreactor(PBNO-Ce6)to amplify the photodynamic and photothermal therapy efficacy against triple-negative breast cancer(TNBC).The designed PBNOCe6 combines sodium nitroprusside-doped Prussian Blue nanoparticles with Chlorin e6 to enable on-site RNS production through NIR-induced concurrent NO release and ROS generation.This not only enhances tumor cell eradication but also potentiates local and systemic antitumor immune responses,protecting mice from tumor rechallenge.Our in vivo evaluations revealed that treatment with PBNO-Ce6 leads to a remarkable 2.7-fold increase in cytotoxic T lymphocytes and a 62%decrease in regulatory T cells in comparison to the control PB-Ce6(Prussian Blue nanoparticles loaded with Chlorin e6),marking a substantial improvement over traditional PTT/PDT.As such,the PBNO-Ce6 nanoreactor represents a transformative approach for improving outcomes in TNBC and potentially other malignancies affected by similar barriers.

Photoactivatable nanogenerators of reactive species for cancer therapy

In recent years,reactive species-based cancer therapies have attracted tremendous attention due to their simplicity,controllability,and effectiveness.Herein,we overviewed the state-of-art advance for photo-controlled generation of highly reactive radical species with nanomaterials for cancer therapy.First,we summarized the most widely explored reactive species,such as singlet oxygen,superoxide radical anion(O2●-),nitric oxide(●NO),carbon monoxide,alkyl radicals,and their corresponding secondary reactive species generated by interaction with other biological molecules.Then,we discussed the generating mechanisms of these highly reactive species stimulated by light irradiation,followed by their anticancer effect,and the synergetic principles with other therapeutic modalities.This review might unveil the advantages of reactive species-based therapeutic methodology and encourage the pre-clinical exploration of reactive species-mediated cancer treatments.

活性氧/活性氮与NF-κB信号通路级联交互在肝纤维化中的作用

肝纤维化是慢性肝损伤后组织修复过程中的代偿反应,也是诸多慢性肝病发展必经的病理过程。在病理状态下,肝脏氧化系统与抗氧化系统失衡,造成活性氧/活性氮产生过多或清除不足,诱导肝细胞损伤,扩大炎症反应,促进肝纤维化的发生发展。NF-κB作为炎症反应和氧化应激的主调控器,在肝纤维化进程中发挥关键作用。因此,活性氧/活性氮与NF-κB信号通路的级联交互关系对于进一步阐明肝纤维化的发病机制,探索有效的防治策略起到重要的指导作用。本文即对两者之间的交互关系及在肝纤维化进程中的重要作用进行综述和讨论,以期为肝纤维化的靶向治疗提供策略和参考。

葡萄籽原花青素提取物抗氧化作用研究

为研究葡萄籽原花青素提取物(grapeprocyanidinsextract,GPE)抗氧化和对DNA氧化损伤的保护作用,我们采用七种生物化学发光体系,检测了GPE对O·2、·OH、H2O2、ONOO-和全血嗜中性白细胞"呼吸爆发"产生的多种活性氧的清除作用,以及对·OH引起的DNA氧化损伤的保护作用;采用Fe2+诱发脂蛋白多不饱和脂肪酸过氧化比色体系,检测了GPE对脂质过氧化的抑制作用。结果显示,GPE能有效地清除O·2、·OH、H2O2、ONOO-和全血嗜中性白细胞"呼吸爆发"产生的多种活性氧而抑制体系发光,并有效抑制脂质过氧化,半抑制浓度分别约为0.2μg ml、90μg ml、0.5μg ml、10μg ml、130μg ml及70μg ml;25μg ml的GPE对DNA氧化损伤的抑制率约为70%。提示GPE能有效清除多种自由基,保护DNA免受·OH引起的氧化损伤,是良好的抗氧化剂。