Methylated CpG dinucleotides in the 5 -a reductase 2 gene may explain finasteride resistance in benign prostatic enlargement patients

The inhibition of 5-a reductase type 2(SRD5A2)by finasteride is commonly used for the management of urinary obstruction resulting from benign prostatic enlargement(BPE).Certain BPE patients showing no SRD5A2 protein expression are resistant to finasteride therapy.Our previous work showed that methylated cytosine-phosphate-guanine(CpG)islands in the SRD5A2 gene might account for the absence or reduction of SRD5A2 protein expression.Here,we found that the expression of the SRD5A2 protein was variable and that weak expression of the SRD5A2 protein(scored 0-100)occurred in 10.0%(4/40)of benign adult prostates.We showed that the expression of SRD5A2 was negatively correlated with DNA methyltransferase 1(DNMT1)expression.In vitro SRD5A2-negative BPH-1 cells were resistant to finasteride treatment,and SRD5A2 was re-expressed in BPH-1 cells when SRD5A2 was demethylated by 5-Aza-2T-deoxycytidine(5-Aza-CdR)or N-phthalyl-L-tryptophan(RG108).Furthermore,we determined the exact methylation ratios of CpG dinucleotides in a CpG island of SRD5A2 through MassArray quantitative methylation analysis.Ten methylated CpG dinucleotides,including four CpG dinucleotides in the promoter and six CpG dinucleotides in the first exon,were found in a CpG island located from-400 bp to+600 bp in SRD5A2,which might lead to the silencing of SRD5A2 and the absence or reduction of SRD5A2 protein expression.Finasteride cannot exert a therapeutic effect on patients lacking SRD5A2,which may partially account for the resistance to finasteride observed in certain BPE patients.

Design, synthesis and systematic evaluation of all possible cyclic dinucleotides (CDNs) that activate human stimulator of interferon genes (STING) variants

Cyclic dinucleotides(CDNs) are known to activate stimulator of interferon genes(STING) and induce type I interferon responses, therefor possess great potentials to be of immunotherapeutic value for cancers and infectious diseases. However, the existence of different single nucleotide polymorphism(SNP) of human STING(hSTING) gene poses an obstacle to achieve broad-spectrum activation by CDNs. We reported here the design and synthesis of a total of 36 CDNs, representing all structural variations, that contain four bases(A, G, C, U) and two linkage directions(2′-5′-linked and 3′-5′-linked phosphodiester).Through systematic evaluation of IFN-β induction with a dual-luciferase reporter assay, we discovered that wild type hSTING and two isoforms(HAQ and AQ) showed strong response while hSTING-R232 H and R293 Q exhibited the relatively weak response to CDNs stimulation. For the first time, we found that the c[G(2′,5′)U(2′,5′)] showed excellent activity against all five hSTING variants even equivalent to the endogenous ligand c[G(2′,5′)A(3′,5′)]. Furthermore, we have also demonstrated that 3′-3′CDNs with two 3′-5′ phosphodiesters showed higher serum and hydrolase stability than 2′-2′ CDNs with two 2′-5′ phosphodiesters and 2′-3′ CDNs with one 2′-5′ and one 3′-5′ phosphodiester. It is very interesting to note that 2′-2′ CDNs has been found for the first time to show strong activity. These findings will stimulate our exploration for the new functional role of CDNs, and provide guidelines to design CDNs based hSTING targeted drugs.

Nicotinamide adenine dinucleotide treatment confers resistance to neonatal ischemia and hypoxia:effects on neurobehavioral phenotypes

Neonatal hypoxic-ischemic brain injury is the main cause of hypoxic-ischemic encephalopathy and cerebral palsy.Currently,there are few effective clinical treatments for neonatal hypoxic-ischemic brain injury.Here,we investigated the neuroprotective and molecular mechanisms of exogenous nicotinamide adenine dinucleotide,which can protect against hypoxic injury in adulthood,in a mouse model of neonatal hypoxic-ischemic brain injury.In this study,nicotinamide adenine dinucleotide(5 mg/kg)was intraperitoneally administered 30 minutes befo re surgery and every 24 hours thereafter.The results showed that nicotinamide adenine dinucleotide treatment improved body weight,brain structure,adenosine triphosphate levels,oxidative damage,neurobehavioral test outcomes,and seizure threshold in experimental mice.Tandem mass tag proteomics revealed that numerous proteins were altered after nicotinamide adenine dinucleotide treatment in hypoxic-ischemic brain injury mice.Parallel reaction monitoring and western blotting confirmed changes in the expression levels of proteins including serine(or cysteine)peptidase inhibitor,clade A,member 3N,fibronectin 1,5'-nucleotidase,cytosolic IA,microtubule associated protein 2,and complexin 2.Proteomics analyses showed that nicotinamide adenine dinucleotide ameliorated hypoxic-ischemic injury through inflammation-related signaling pathways(e.g.,nuclear factor-kappa B,mitogen-activated protein kinase,and phosphatidylinositol 3 kinase/protein kinase B).These findings suggest that nicotinamide adenine dinucleotide treatment can improve neurobehavioral phenotypes in hypoxic-ischemic brain injury mice through inflammation-related pathways.

Emerging mechanisms and implications of c GAS-STING signaling in cancer immunotherapy strategies

The intricate interplay between the human immune system and cancer development underscores the central role of immunotherapy in cancer treatment.Within this landscape,the innate immune system,a critical sentinel protecting against tumor incursion,is a key player.The cyclic GMP-AMP synthase(c GAS)and stimulator of interferon genes(STING)pathway has been found to be a linchpin of innate immunity:activation of this signaling pathway orchestrates the production of type I interferon(IFN-α/β),thus fostering the maturation,differentiation,and mobilization of immune effectors in the tumor microenvironment.Furthermore,STING activation facilitates the release and presentation of tumor antigens,and therefore is an attractive target for cancer immunotherapy.Current strategies to activate the STING pathway,including use of pharmacological agonists,have made substantial advancements,particularly when combined with immune checkpoint inhibitors.These approaches have shown promise in preclinical and clinical settings,by enhancing patient survival rates.This review describes the evolving understanding of the c GAS-STING pathway's involvement in tumor biology and therapy.Moreover,this review explores classical and non-classical STING agonists,providing insights into their mechanisms of action and potential for optimizing immunotherapy strategies.Despite challenges and complexities,the c GAS-STING pathway,a promising avenue for enhancing cancer treatment efficacy,has the potential to revolutionize patient outcomes.

Association of Human Whole-blood NAD+Levels with Nabothian Cyst

Objective Little is known about the association between whole-blood nicotinamide adenine dinucleotide(NAD^(+))levels and nabothian cysts.This study aimed to assess the association between NAD^(+)levels and nabothian cysts in healthy Chinese women.Methods Multivariate logistic regression analysis was performed to analyze the association between NAD^(+)levels and nabothian cysts.Results The mean age was 43.0±11.5 years,and the mean level of NAD^(+)was 31.3±5.3μmol/L.Nabothian cysts occurred in 184(27.7%)participants,with single and multiple cysts in 100(15.0%)and84(12.6%)participants,respectively.The total nabothian cyst prevalence gradually decreased from37.4%to 21.6%from Q1 to Q4 of NAD^(+)and the prevalence of single and multiple nabothian cysts also decreased across the NAD^(+)quartiles.As compared with the highest NAD^(+)quartile(≥34.4μmol/L),the adjusted odds ratios with 95%confidence interval of the NAD^(+)Q1 was 1.89(1.14–3.14)for total nabothian cysts.The risk of total and single nabothian cysts linearly decreased with increasing NAD^(+)levels,while the risk of multiple nabothian cysts decreased more rapidly at NAD^(+)levels of 28.0 to35.0μmol/L.Conclusion:Low NAD^(+)levels were associated with an increased risk of total and multiple nabothian cysts.

Nicotinamide adenine dinucleotide phosphate oxidase in pancreatic diseases:Mechanisms and future perspectives

Pancreatitis and pancreatic cancer(PC)stand as the most worrisome ailments affecting the pancreas.Researchers have dedicated efforts to unraveling the mechanisms underlying these diseases,yet their true nature continues to elude their grasp.Within this realm,oxidative stress is often believed to play a causal and contributory role in the development of pancreatitis and PC.Excessive accumulation of reactive oxygen species(ROS)can cause oxidative stress,and the key enzyme responsible for inducing ROS production in cells is nicotinamide adenine dinucleotide phosphate hydrogen oxides(NOX).NOX contribute to pancreatic fibrosis and inflammation by generating ROS that injure acinar cells,activate pancreatic stellate cells,and mediate macrophage polarization.Excessive ROS production occurs during malignant transformation and pancreatic carcinogenesis,creating an oxidative microenvironment that can cause abnormal apoptosis,epithelial to mesenchymal transition and genomic instability.Therefore,understanding the role of NOX in pancreatic diseases contributes to a more in-depth exploration of the exact pathogenesis of these diseases.In this review,we aim to summarize the potential roles of NOX and its mechanism in pancreatic disorders,aiming to provide novel insights into understanding the mechanisms underlying these diseases.

NOX4 promotes tumor progression through the MAPK-MEK1/2-ERK1/2 axis in colorectal cancer

BACKGROUND Metabolic reprogramming plays a key role in cancer progression and clinical outcomes;however,the patterns and primary regulators of metabolic reprogramming in colorectal cancer(CRC)are not well understood.AIM To explore the role of nicotinamide adenine dinucleotide phosphate oxidase 4(NOX4)in promoting progression of CRC.METHODS We evaluated the expression and function of dysregulated and survival-related metabolic genes using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes.Consensus clustering was used to cluster CRC based on dysregulated metabolic genes.A prediction model was constructed based on survival-related metabolic genes.Sphere formation,migration,invasion,proliferation,apoptosis and clone formation was used to evaluate the biological function of NOX4 in CRC.mRNA sequencing was utilized to explore the alterations of gene expression NOX4 over-expression tumor cells.In vivo subcutaneous and lung metastasis mouse tumor model was used to explore the effect of NOX4 on tumor growth.RESULTS We comprehensively analyzed 3341 metabolic genes in CRC and identified three clusters based on dysregulated metabolic genes.Among these genes,NOX4 was highly expressed in tumor tissues and correlated with worse survival.In vitro,NOX4 overexpression induced clone formation,migration,invasion,and stemness in CRC cells.Furthermore,RNA-sequencing analysis revealed that NOX4 overexpression activated the mitogen-activated protein kinase-MEK1/2-ERK1/2 signaling pathway.Trametinib,a MEK1/2 inhibitor,abolished the NOX4-mediated tumor progression.In vivo,NOX4 overexpression promoted subcutaneous tumor growth and lung metastasis,whereas trametinib treatment can reversed the metastasis.CONCLUSION Our study comprehensively analyzed metabolic gene expression and highlighted the importance of NOX4 in promoting CRC metastasis,suggesting that trametinib could be a potential therapeutic drugs of CRC clinical therapy targeting NOX4.

RNase A-catalyzed synthesis of dinucleotides containing 2' -deoxy-2' -fluoro-pyrimidinenucleosides at 3'-termini

RNase A catalyzes the hydrolysis of ribonucleic acids to form oligonucleotide fragments containing pyrimidineribonucleoside 2’, 3’-cyclic phosphate at the 3’-termini, which are then further hydrolyzed to produce oligonucleotide fragments with 3’ -phosphate group as the final products. This enzyme can also catalyze the formation of internucleotide linkage from pyrimidineribonucleoside 2’, 3’-cyclic phosphate and a nucleoside component with

活性氧在免疫应答中的作用

活性氧（Reactive oxygen species,ROS）是一群具有较强氧化能力的分子的总称[1]。生物体内的ROS包括超氧阴离子（O·-2）、羟自由基（·OH）、过氧化氢（H2O2）、单线态氧（O2）。活性氧在免疫系统中主要来源于细胞膜的NADPH氧化酶复合体2（Nicotinamide adenine dinucleotide phosphate oxidase,NOX2）,并在淋巴细胞间的信号转导发挥巨大作用。

Interaction between N-phosphoryl-α-,β-and γ-amino acids and nucleosides

The reactions of four different N-（O,O＇-diisopropyl） phosphoamino acids （DIPP-aa）, such as N-phosphoryl-L-α-alanine （DIPP- L-α-Ala）, N-phosphoryl-D-α-alanine （DIPP-D-α-A1a）, N-phosphoryl-β-alanine （DIPP-β-A1a） and N-phosphoryl-γ-amino butyric acid （DIPP-γ-Aba）, and four nucleosides, adenosine （A）, guanosine （G）, cytidine （C） and uridine （U）, were studied by electrospray ionization tandem mass spectrometry （ESI-MS/MS） and HPLC/ESI-MS. DIPP-L-α-A1a and DIPP-D-α-A1a produced the same phosphorylated nucleosides, dinucleotides and phosphoroligopeptide. However, DIPP-β-A1a and DIPP-γ-Aba gave no relevant products.

Statistical analysis of conformational properties of periodic dinucleotide steps in nucleosomes

Deformability of DNA is important for its superhelical folding in the nucleosome and has long been thought to be facilitated by periodic occurrences of certain dinucleotides along the sequences, with the period close to 10.5 bases. This study statistically examines the conformational properties of dinucleotides containing the 10.5 - base periodicity and those without that periodicity through scanning all nucleosome structures provided in PDB. By categorizing performances on the distribution of step parameter values, averaged net values, standard deviations and deformability based on step conformational energies, we give a detailed description as to the deformation preferences correlated with the periodicity for the 10 unique types of dinucleotides and summarize the possible roles of various steps in how they facilitate DNA bending. The results show that the structural properties of dinucleotide steps are influenced to various extents by the periodicity in nucleosomes and some periodic steps have shown a clear tendency to take specific bending or shearing patterns.

Contribution of oxidative stress to pulmonary arterial hypertension

Recent data implicate oxidative stress as a mediator of pulmonary hypertension (PH) and of the associated pathological changes to the pulmonary vasculature and right ventricle (RV). Increases in reactive oxygen species (ROS), altered redox state, and elevated oxidant stress have been demonstrated in the lungs and RV of several animal models of PH, including chronic hypoxia, monocrotaline toxicity, caveolin-1 knock-out mouse, and the transgenic Ren2 rat which overexpresses the mouse renin gene. Generation of ROS in these models is derived mostly from the activities of the nicotinamide adenine dinucleotide phosphate oxidases, xanthine oxidase, and uncoupled endothelial nitric oxide synthase. As disease progresses circulating monocytes and bone marrow-derived monocytic progenitor cells are attracted to and accumulate in the pulmonary vasculature. Once established, these inflammatory cells generate ROS and secrete mitogenic and fibrogenic cytokines that induce cell proliferation and fibrosis in the vascular wall resulting in progressive vascular remodeling. Deficiencies in antioxidant enzymes also contribute to pulmonary hypertensive states. Current therapies were developed to improve endothelial function, reduce pulmonary artery pressure, and slow the progression of vascular remodeling in the pulmonary vasculature by targeting deficiencies in either NO (PDE-type 5 inhibition) or PGI 2 (prostacyclin analogs), or excessive synthesis of ET-1 (ET receptor blockers) with the intent to improve patient clinical status and survival. New therapies may slow disease progression to some extent, but long term management has not been achieved and mortality is still high. Although little is known concerning the effects of current pulmonary arterial hypertension treatments on RV structure and function, interest in this area is increasing. Development of therapeutic strategies that simultaneously target pathology in the pulmonary vasculature and RV may be beneficial in reducing mortality associated with RV failure.

NADPH氧化酶及其产物活性氧在急性肾损伤中的作用及研究进展

急性肾损伤（acute kidney injury,AKI）是一组以肾小球滤过率迅速下降为主要特点的临床综合征。氧化应激、细胞凋亡、炎症反应与AKI的发生发展密切相关。还原型烟酰胺腺嘌呤二核苷酸磷酸（nicotinamide adenine dinucleotide phosphate,NADPH）氧化酶是产生活性氧（reactive oxygen species,ROS）的众多来源之一,由七种亚型（Noxl、Nox2、Nox3、Nox4、Nox5、Duoxl和Duox2）组成,统称为Nox家族。NADPH氧化酶（NADPH oxidases,Nox）及其产物ROS在AKI的发生发展上起关键性作用,可能是其主要发病机制之一。

Nicotinamide adenine dinucleotide phosphate oxidase activation and neuronal death after ischemic stroke

Nicotinamide adenine dinucleotide phosphate oxidase(NOX) is a multisubunit enzyme complex that utilizes nicotinamide adenine dinucleotide phosphate to produce superoxide anions and other reactive oxygen species. Under normal circumstances, reactive oxygen species mediate a number of important cellular functions, including the facilitation of adaptive immunity. In pathogenic circumstances, however,excess reactive oxygen species generated by NOX promotes apoptotic cell death. In ischemic stroke, in particular, it has been shown that both NOX activation and derangements in glucose metabolism result in increased apoptosis. Moreover, recent studies have established that glucose, as a NOX substrate, plays a vital role in the pathogenesis of reperfusion injury. Thus, NOX inhibition has the potential to mitigate the deleterious impact of hyperglycemia on stroke. In this paper, we provide an overview of this research,coupled with a discussion of its implications for the development of NOX inhibition as a strategy for the treatment of ischemic stroke. Both inhibition using apocynin, as well as the prospect of developing more specific inhibitors based on what is now understood of the biology of NOX assembly and activation, will be highlighted in the course of our discussion.

Novel association between sperm deformity index and oxidative stress-induced DNA damage in infertile male patients

Aim:To investigate the impact of abnormal sperm morphology using the sperm deformity index (SDI) on reactive oxygen species (ROS) production and its correlation with sperm DNA damage.Methods:Semen samples were collected from men undergoing infertility screening (n=7) and healthy donors (n=6).Mature spermatozoa were isolated and incubated with 5 mmol/L β-nicotinamide adenine dinucleotide phosphate (NADPH) for up to 24 h to induce ROS.Sperm morphology was evaluated using strict Tygerberg's criteria and the SDI.ROS levels and DNA damage were assessed using chemiluminescence and terminal deoxynucleotidyl transferase-mediated fluorescein- dUTP nick end labeling (TUNEL) assays,respectively.Results:SDI values (median [interquartiles]) were higher in patients than donors (2 [1.8,2.1] vs.1.53 [1.52,1.58],P=0.008).Aliquots treated with NADPH showed higher ROS levels (1.22 [0.30,1.87] vs.0.39 [0.10,0.57],P=0.03) and higher incidence of DNA damage than those not treated (10 [4.69,24.85] vs.3.85 [2.58,5.10],P=0.008).Higher DNA damage was also seen following 24 h of incubation in patients compared to donors.SDI correlated with the percentage increase in sperm DNA damage following incubation for 24 h in samples treated with NADPH (r=0.7,P=0.008) and controls (r=0.58,P=0.04). Conclusion:SDI may be a useful tool in identifying potential infertile males with abnormal prevalence of oxidative stress (OS)-induced DNA damage.NADPH plays a role in ROS-mediated sperm DNA damage,which appears to be more evident in infertile patients with semen samples containing a high incidence of morphologically abnormal spermatozoa.

Scutellarin protects oxygen/glucose-deprived astrocytes and reduces focal cerebral ischemic injury

Scutellarin, a bioactive flavone isolated from Scutellaria baicalensis, has anti-inflammatory, anti-neurotoxic, anti-apoptotic and anti-oxida- tive effects and has been used to treat cardiovascular and cerebrovascular diseases in China. However, the mechanisms by which scutellarin mediates neuroprotection in cerebral ischemia remain unclear. The interaction between scutellarin and nicotinamide adenine dinucleotide phosphate oxidase 2 （NOX2） was assessed by molecular docking study, which showed that scutellarin selectively binds to NOX2 with high affinity. Cultures of primary astrocytes isolated from the cerebral cortex of neonatal Sprague-Dawley rats were pretreated with 2, 10 or 50 μM scutellarin for 30 minutes. The astrocytes were then subjected to oxygen/glucose deprivation by incubation for 2 hours in glucose-free Dulbecco＇s modified Eagle＇s medium in a 95% N2/5% CO2 incubator, followed by simulated reperfusion for 22 hours. Cell viability was assessed by cell counting kit-8 assay. Expression levels of NOX2, connexin 43 and caspase-3 were assessed by western blot assay. Reactive oxygen species were measured spectrophotometrically. Pretreatment with 10 or 50 μM scutellarin substantially increased viability, reduced the expression of NOX2 and caspase-3, increased the expression of connexin 43, and diminished the levels of reactive oxygen, species in astrocytes subjected to ischemia-＇reperfusion. We also assessed the effects of scutellarin in vivo in the rat transient middle cerebral artery occlusion model of cerebral ischemia-reperfusion injury. Rats were given intraperitoneal injection of 100 mg/kg scutellarin 2 hours before surgery. The Bederson scale was used to assess neurological deficit, and 2,3,5-triphenyltetrazolium chloride staining was used to measure infarct size. Western blot assay was used to assess expression of NOX2 and connexin 43 in brain tissue. Enzyme-linked immunosorbent assay was used to detect 8-hydroxydeoxyguanosine （8-OHdG）, 4-hydroxy-2-nonenal （4-HNE） and 3-nitrotyrosin （3-NT） in brain tissue. Immunofluorescence double staining was used to determine the co-expression of caspase-3 and NeuN. Pretreatment with scutellarin im- proved the neurological function of rats with focal cerebral ischemia, reduced infarct size, diminished the expression of NOX2, reduced levels of 8-OHdG, 4-HNE and 3-NT, and reduced the number of cells co-expressing caspase-3 and NeuN in the injured brain tissue. Furthermore, we examined the effect of the NOX2 inhibitor apocynin. Apocynin substantially increased connexin 43 expression in vivo and in vitro. Collectively, our findings suggest that scutellarin protects against ischemic injury in vitro and in vivo by downregulating NOX2, upregulating connexin 43, decreasing oxidative damage, and reducing apoptotic cell death.

Abdominal paracentesis drainage ameliorates myocardial injury in severe experimental pancreatitis rats through suppressing oxidative stress

BACKGROUND Abdominal paracentesis drainage(APD)is a safe and effective strategy for severe acute pancreatitis(SAP)patients.However,the effects of APD treatment on SAPassociated cardiac injury remain unknown.AIM To investigate the protective effects of APD on SAP-associated cardiac injury and the underlying mechanisms.METHODS SAP was induced by 5%sodium taurocholate retrograde injection in Sprague-Dawley rats.APD was performed by inserting a drainage tube with a vacuum ball into the lower right abdomen of the rats immediately after SAP induction.Morphological staining,serum amylase and inflammatory mediators,serum and ascites high mobility group box(HMGB)1,cardiac-related enzymes indexes and cardiac function,oxidative stress markers and apoptosis and associated proteins were assessed in the myocardium in SAP rats.Nicotinamide adenine dinucleotide phosphate oxidase activity and mRNA and protein expression were also examined.RESULTS APD treatment improved cardiac morphological changes,inhibited cardiac dysfunction,decreased cardiac enzymes and reduced cardiomyocyte apoptosis,proapoptotic Bax and cleaved caspase-3 protein levels.APD significantly decreased serum levels of HMGB1,inhibited nicotinamide adenine dinucleotide phosphate oxidase expression and ultimately alleviated cardiac oxidative injury.Furthermore,the activation of cardiac nicotinamide adenine dinucleotide phosphate oxidase by pancreatitis-associated ascitic fluid intraperitoneal injection was effectively inhibited by adding anti-HMGB1 neutralizing antibody in rats with mild acute pancreatitis.CONCLUSION APD treatment could exert cardioprotective effects on SAP-associated cardiac injury through suppressing HMGB1-mediated oxidative stress,which may be a novel mechanism behind the effectiveness of APD on SAP.

MITOCHONDRIAL REDOX IMAGING FOR CANCER DIAGNOSTIC AND THERAPEUTIC STUDIES

Mitochondrial redox states provide important information about energy-linked biological processes and signaling events in tissues for various disease phenotypes including cancer.The redox scanning method developed at the Chance laboratory about 30 years ago has allowed 3D highresolution(∼50×50×10µm^(3))imaging of mitochondrial redox state in tissue on the basis of the fluorescence of NADH(reduced nicotinamide adenine dinucleotide)and Fp(oxidized flavoproteins including flavin adenine dinucleotide,i.e.,FAD).In this review,we illustrate its basic principles,recent technical developments,and biomedical applications to cancer diagnostic and therapeutic studies in small animal models.Recently developed calibration procedures for the redox imaging using reference standards allow quantification of nominal NADH and Fp concentrations,and the concentration-based redox ratios,e.g.,Fp/(Fp+NADH)and NADH/(Fp+NADH)in tissues.This calibration facilitates the comparison of redox imaging results acquired for different metabolic states at different times and/or with different instrumental settings.A redox imager using a CCD detector has been developed to acquire 3D images faster and with a higher in-plane resolution down to 10µm.Ex vivo imaging and in vivo imaging of tissue mitochondrial redox status have been demonstrated with the CCD imager.Applications of tissue redox imaging in small animal cancer models include metabolic imaging of glioma and myc-induced mouse mammary tumors,predicting the metastatic potentials of human melanoma and breast cancer mouse xenografts,differentiating precancerous and normal tissues,and monitoring the tumor treatment response to photodynamic therapy.Possible future directions for the development of redox imaging are also discussed.

Oxidative and nitrosative stress enzymes in relation to nitrotyrosine in Helicobacter pylori-infected humans

AIM: To compare a possible relation between Helicobacter pylori(H. pylori) and the oxygen- and nitrogen radical system in humans. METHODS: Mechanisms for H. pylori to interfere with the oxygen and nitrogen radical system is of great importance for understanding of the H. pylori persistence and pathogenesis. Biopsies were obtained from the gastric wall of 21 individuals. Ongoing infection with H. pylori was detected using direct analyze from the biopsies using campylobacter-like organism test(CLO-test) and/or by using 14C-urea breath test. The individuals were divided in a negative H. pylori and a positive H. pylori group. Expression in the gastric mucosa of induc-ible nitric oxide syntase(iNOS), nicotinamide adenine dinucleotide phosphate-oxidase(NADPH-oxidase) myeloperoxidase(MPO), and nitrotyrosine were assessed by Western blotting.RESULTS: The individuals who undervent gastroscopy were divided in a H. pylori neg. [n = 13, m/f = 7/6, age(mean) = 39] and a H. pylori pos. group [n = 8, m/f = 5/3, age(mean) = 53]. Using western blot analysis iNOS was detected as a 130 kDa band. The iNOS expression was upregulated in the antrum of H. pylori infected individuals in comparison to the controls, mean ± SD being 12.6 ± 2.4 vs 8.3 ± 3.1, P < 0.01. There was a markedly upregulated expression of MPO in the antrum of H. pylori infected individuals in comparison to the control group without infection. In several of noninfected controls it was not possible to detect any MPO expression at all, whereas the expression was high in all the infected subjects, mean ± SD being 5.1 ± 3.4 vs 2.1 ± 1.9, P < 0.05. The NADPH-oxidase expression was analysed by detecting the NADPH-oxidase subunit p47-phox expression. P47-phox was detected as a 47 kDa band using Western blot, and showed a significantly higher expression of p47-phox in the antrum of the H. pylori infected individuals compared to the controls, mean ± SD being 3.1 ± 2.2 vs 0.3 ± 0.2, P < 0.01. Regarding nitrotyrosine formation, Western blot did not show any significant increase or decrease compared to controls, 7.0 ± 0.9 vs 6.9 ± 1.1, not significant.CONCLUSION: iNOS, MPO and NADPH-oxidase was up-regulated among H. pylori infected. Regarding nitrotyrosine no difference was found. This support an H. pylori related inhibition of radical formation.

Potential role of NADPH oxidase in pathogenesis of pancreatitis

Studies have demonstrated that reactive oxygen species(ROS) are closely related to inflammatory disorders. Nicotinamide adenine dinucleotide phosphate oxidase(NOX), originally found in phagocytes, is the main source of ROS in nonphagocytic cells. Besides directly producing the detrimental highly reactive ROS to act on biomolecules(lipids, proteins, and nucleic acids), NOX can also activate multiple signal transduction pathways, which regulate cell growth, proliferation, differentiation and apoptosis by producing ROS. Recently, research on pancreatic NOX is no longer limited to inflammatory cells, but extends to the aspect of pancreatic acinar cells and pancreatic stellate cells, which are considered to be potentially associated with pancreatitis. In this review, we summarize the literature on NOX protein structure, activation, function and its role in the pathogenesis of pancreatitis.