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.

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.

Repetitive administration of cultured human CD34+cells improve adenine-induced kidney injury in mice

BACKGROUND There is no established treatment to impede the progression or restore kidney function in human chronic kidney disease(CKD).AIM To examine the efficacy of cultured human CD34+cells with enhanced proliferating potential in kidney injury in mice.METHODS Human umbilical cord blood(UCB)-derived CD34+cells were incubated for one week in vasculogenic conditioning medium.Vasculogenic culture significantly increased the number of CD34+cells and their ability to form endothelial progenitor cell colony-forming units.Adenineinduced tubulointerstitial injury of the kidney was induced in immunodeficient non-obese diabetic/severe combined immunodeficiency mice,and cultured human UCB-CD34+cells were administered at a dose of 1×106/mouse on days 7,14,and 21 after the start of adenine diet.RESULTS Repetitive administration of cultured UCB-CD34+cells significantly improved the time-course of kidney dysfunction in the cell therapy group compared with that in the control group.Both interstitial fibrosis and tubular damage were significantly reduced in the cell therapy group compared with those in the control group(P<0.01).Microvasculature integrity was significantly preserved(P<0.01)and macrophage infiltration into kidney tissue was dramatically decreased in the cell therapy group compared with those in the control group(P<0.001).CONCLUSION Early intervention using human cultured CD34+cells significantly improved the progression of tubulointerstitial kidney injury.Repetitive administration of cultured human UCB-CD34+cells significantly improved tubulointerstitial damage in adenine-induced kidney injury in mice via vasculoprotective and anti-inflammatory effects.

Adenine phosphoribosyltransferase deficiency: Leave no stone unturned

Adenine phosphoribosyltransferase(APRT)deficiency is a rare autosomal recessive disease leading to generation of large amounts of 2,8-dihydroxyadenine(DHA).DHA is excreted in urine,where it precipitates into crystals due to its low solubility.DHA crystals can aggregate into stones or cause injury to the renal parenchyma(DHA nephropathy).Recurrent urolithiasis and DHA nephropathy are the two clinical manifestations of APRT deficiency.Diagnosis of APRT deficiency can be made during childhood as well as adulthood.Diagnosis mainly relies on the recognition of DHA in stones or urine crystals.Measurement of APRT activity and genetic testing are useful for confirmation of diagnosis,for family screening and should be considered in difficult cases of urolithiasis or crystalline nephropathy.Allopurinol therapy is the cornerstone of treatment and is highly effective in preventing recurrence of stones and kidney disease.High fluid intake and dietary modifications are also recommended.Early diagnosis and treatment are of paramount importance to prevent renal damage.Unfortunately,diagnosis of APRT deficiency is often overlooked and irreversible renal failure still occurs in a substantial proportion of patients.Clinicians must be alert to the possibility of APRT deficiency and consider the appropriate diagnostic tests in certain cases.This review discusses the genetic and biochemical mechanisms of APRT deficiency,and the issues of diagnosis and management.

Adenine制作雄性Wistar大鼠不育症动物模型最佳时相的小样本研究

目的:探讨阿拉伯胶助溶后的Aden ine对W istar大鼠生殖毒性的时效关系。方法:将Aden ine按500mg/mL浓度配制,按与Aden ine 1∶10比例加入阿拉伯胶作为助溶剂,1mL/kg.d-1剂量灌胃,每3天处死1组,做精子质量分析、用放免法检测性激素的变化,并对时效关系进行了观察。结果:精子活动率及密度随给药时间延长呈下降趋势,在给药后第15天精子活动率呈显著性差异;睾酮(T)呈进行性下降,给药后前者第3天、后者第12天全部即出现显著性差异,FSH呈进行性上升,第9天出现显著性差异,第12天秩次最高。结论:初步推定将Aden ine按500mg/mL浓度配制,并加助溶剂后,1mL/kg.d-1剂量W istar大鼠灌胃12天为其生殖毒性反映最佳时效,也可能为该给药剂量雄性大鼠不育症模型的最佳时相。

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.

OTOTOXIC MODEL OF OXALIPLATIN AND PROTECTION FROM NICOTINAMIDE ADENINE DINUCLEOTIDE

Oxaliplatin, an anticancer drug commonly used to treat colorectal cancer and other tumors, has a number of serious side effects, most notably neuropathy and ototoxicity. To gain insights into its ototoxic profile, oxaliplatin was applied to rat cochlear organ cultures. Consistent with it neurotoxic propensity, oxaliplatin selectively damaged nerve fibers at a very low dose 1 μM. In contrast, the dose required to damage hair cells and spiral ganglion neurons was 50 fold higher (50 μM). Oxailiplatin-induced cochlear lesions initial-ly increased with dose, but unexpectedly decreased at very high doses. This non-linear dose response could be related to depressed oxaliplatin uptake via active transport mechanisms. Previous studies have demon-strated that axonal degeneration involves biologically active processes which can be greatly attenuated by nicotinamide adenine dinucleotide (NAD+). To determine if NAD+would protect spiral ganglion axons and the hair cells from oxaliplatin damage, cochlear cultures were treated with oxaliplatin alone at doses of 10 μM or 50 μM respectively as controls or combined with 20 mM NAD+. Treatment with 10 μM oxaliplatin for 48 hours resulted in minor damage to auditory nerve fibers, but spared cochlear hair cells. However, when cochlear cultures were treated with 10 μM oxaliplatin plus 20 mM NAD+, most auditory nerve fibers were intact. 50 μM oxaliplatin destroyed most of spiral ganglion neurons and cochlear hair cells with apop-totic characteristics of cell fragmentations. However, 50 μM oxaliplatin plus 20 mM NAD+treatment great-ly reduced neuronal degenerations and hair cell missing. The results suggested that NAD+provides signifi-cant protection against oxaliplatin-induced neurotoxicity and ototoxicity, which may be due to its actions of antioxidant, antiapoptosis, and energy supply.

CRISPR/Cas9-Mediated Adenine Base Editing in Rice Genome

Precise base editing is highly desired in plant functional genomic research and crop molecular breeding. In this study, we constructed a rice-codon optimized adenine base editor(ABE)-nC as9 tool that induced targeted A·T to G·C point mutation of a key single nucleotide polymorphism site in an important agricultural gene. Combined with the modified single-guide RNA variant, our plant ABE tool can efficiently achieve adenine base editing in the rice genome.

Two Preparation Methods-dominated Cd^(Ⅱ)-Based Coordination Polymers with Mixed Adenine Nucleobase and 5-Nitroisophathalate Ligands: Synthesis, Structure and Fluorescence

Two new CdⅡ-based coordination polymers(CPs) with mixed adenine(Hade) nucleobase and 5-nitroisophathalate(nip) ligands, {[Cd(Hade)_(0.5)(H_2O)_2(nip)]·H_2O}n 1 and {[Cd(Hade)(H_2O)_(1.25)(CH_3OH)0.75(nip)]·0.75 CH_3OH·0.5H_2 O}_n 2, were successfully obtained by varying the preparation methods and structurally characterized. Crystal data for 1: monoclinic, C2/c space group with a = 10.5546(6), b = 17.3496(6), c = 16.1198(9) ?, β = 104.2800(10)o, V = 2860.6(2) ?3, Dc = 2.058 g/cm^3, Mr = 443.13, Z = 8, F(000) = 1752, μ = 1.585 mm^(–1), the final R = 0.0394 and wR = 0.1109 for 2285 observed reflections with I > 2σ(I). For 2: triclinic, P1 space group with a = 10.2032(7), b = 10.5098(8), c = 11.0223(8) ?, a = 65.7050(10)o, β = 74.5750(10)o, g = 61.5280(10)o, V = 943.38(12) ?~3, Dc = 1.888 g/cm3, Mr = 536.24, Z = 2, F(000) = 537, μ = 1.225 mm^(–1), the final R = 0.0225 and wR = 0.0702 for 3143 observed reflections with I > 2σ(I). 1 presents a crisscrossed layer with mutually orthogonal {Cd(nip)} chains aggregated by neutral m-N(7),N(9)-Hade connector. By contrast, 2 displays a linear chain with CdⅡ ions extended by bis-bidentate chelating-nip2–connectors, which are further assembled into a broad ribbon by N-H···N hydrogen-bonding interactions. Additionally, the two solid-state samples with comparable thermal stability exhibit favorable luminescent emissions at room temperature, suggesting their potential applications as fluorescence materials.

Synthesis of 3－（R）－（Adenin－9＇－yl）－4－（R）－Hydroxy－5－（R）－Hydroxymethyltetrahydrofuran

R)-(adenin-9'-yl)-4-(R)-hydroxy-5-(R)-hydroxymethyltetrahydrofuran was synthesized by the regeoselective substitution of 3, 4-epoxy-(trans)-5-dimethoxymethylterahydrofuran which was obtained ty 4 steps from L-xylose.

MDR:an integrative DNA N6-methyladenine and N4-methylcytosine modification database for Rosaceae

Eukaryotic DNA methylation has been receiving increasing attention for its crucial epigenetic regulatory function.The recently developed single-molecule real-time(SMRT)sequencing technology provides an efficient way to detect DNA N6-methyladenine(6mA)and N4-methylcytosine(4mC)modifications at a single-nucleotide resolution.The family Rosaceae contains horticultural plants with a wide range of economic importance.However,little is currently known regarding the genome-wide distribution patterns and functions of 6mA and 4mC modifications in the Rosaceae.In this study,we present an integrated DNA 6mA and 4mC modification database for the Rosaceae(MDR,http://mdr.xieslab.org).MDR,the first repository for displaying and storing DNA 6mA and 4mC methylomes from SMRT sequencing data sets for Rosaceae,includes meta and statistical information,methylation densities,Gene Ontology enrichment analyses,and genome search and browse for methylated sites in NCBI.MDR provides important information regarding DNA 6mA and 4mC methylation and may help users better understand epigenetic modifications in the family Rosaceae.

Amplification and function analysis of N6-adenine-specific DNA methyltransferase gene in Nilaparvata lugens

Methylation of the N6 position of adenine, termed N6-methyladenine, protects DNA from restriction endonucleases via the host-specific restriction-modification system. N6-methyladenine was discovered and has been well studied in bacteria. N6-adenine-specific DNA methyltransferase（N6AMT） is the main enzyme catalyzing the methylation of the adenine base and knowledge of this enzyme was mainly derived from work in prokaryotic models. However, large-scale gene discovery at the genome level in many model organisms indicated that the N6AMT gene also exists in eukaryotes, such as humans, mice, fruit flies and plants. Here, we cloned a N6AMT gene from Nilaparvata lugens（Nlu-N6AMT） and amplified its fulllength transcript. Then, we carried out a systematic investigation of N6AMT in 33 publically available insect genomes, indicating that all studied insects had N6AMT. Genomic structure analysis showed that insect N6AMT has short introns compared with the mammalian homologs. Domain and phylogenetic analysis indicated that insect N6AMT had a conserved N6-adenine Mlase domain that is specific to catalyze the adenine methylation. Nlu-N6AMT was highly expressed in the adult female. We knocked down Nlu-N6AMT by feeding ds RNA from the second instar nymph to adult female, inducing retard development of adult female. In all, we provide the first genome-wide analysis of N6AMT in insects and presented the experimental evidence that N6AMT might have important functions in reproductive development and ovary maturation.

Synthesis,Structure Characterization and Biological Activity of Adenine Salt of 12-Phosphotungstic Acid

A novel adenine(Ade) salt of 12-phosphotungstic acid was synthesized and characterized by elemental analyses,IR, 1H NMR,CV and single crystal X-ray diffraction. The compound crystallized in a triclinic system with a space group P 1 and a =1.3108(3) nm, b =1.3515(3) nm,c =1.3870(3) nm, V =2.0217(7) nm 3,Z =1,R _1=0.0391,wR _2=0.0959. The structure unit of the complex was constructed from [HPW_ 12 ·O_ 40 ] -,(C_5H_6N_5) + and C_3H_7NO,which further extends to form a novel three-dimensional host-guest network via hydrogen-bonding interactions. The anti-tumor activity of the compound was examined in two human tumor cell lines in vitro .

Effects of Chinese patent medicine Niaoduqing on adenineinduced chronic renal failure in rats

The authors made rat model of chronic renal failure by feeding the animals with foodcontaining 0.5 % adenine and treated with Niaoduqing(NDQ),a Chinese patent medicine,whichcomposed of Rhizoma Rhei,Radix Glycyrrhizae,Radix Paeoniae Alba,etc.The rats were divid-ed into four groups:model control,normal control;and two NDQ-treated groups with high andlow doses separately.The blood tests including urea nitrogen(BUN),serum creatinine(Scr),red blood cell(RBC),hemoglobin (Hb) hematocrit (HCT),sodium (Na),potassium (K),cal-cium(Ca)and phosphate(P)levels were performed atthe fourth week and the eighth week,thetime of sacrifice.The results showed that in the NDQ-treated groups the mean levels of BUN andScr were lower and the mean values of RBC,Hb and HCT,higher than those in the untreatedcontrol group.In the NDQ-treated groups,hyperphosphatemia and hypocalcemia of rats im-proved,the deposited crystals of adenine metabolite and the proliferation of fibroid tissue in kid-ney decreased.These findings indicate that NDQ can ameliorate the symptoms of chronic renalfailure and delay the progress of this disease.

Computational mechanistic investigation of radiation damage of adenine induced by hydroxyl radicals

The radiation damage of adenine base was studied by B3LYP and MP2 methods in the presence of hydroxyl radicals to probe the reactivities of five possible sites of an isolated adenine molecule. Both methods predict that the C8 site is the more vulnerable than the other sites. For its bonding covalently with the hydroxyl radicals, B3LYP predicts a barrierless pathway, while MP2 finds a transition state with an energy of 106.1 kJ/mol. For the hydroxylation at the C2 site, the barrier was calculated to be 165.3 kJ/mol using MP2 method. For the dehydrogenation reactions at five sites of adenine, B3LYP method predicts that the free energy barrier decreases in the order of H8 〉 H2 〉 HN62 〉 HN61 〉 HN9.

Characterization of the Intracellular Distribution of Adenine Nucleotide Translocase (ANT) in Drosophila Indirect Flight Muscles

Background: The high power output necessary for insect flight has driven the evolution of muscles with large myofibrils (primary energy consumers) and abundant mitochondria (primary energy suppliers). The intricate functional interrelationship between these two organelles remains largely unknown despite its fundamental importance in understanding insect flight bioenergetics. Unlike vertebrate muscle that relies on a phosphagen (creatine phosphate/creatine kinase) system to regulate high energy phosphate flux, insect flight muscle has been reported to lack mitochondrial arginine kinase (analogous to creatine kinase), a key enzyme that enables intracellular energy transport. Creatine kinase is known to interact with mitochondrial adenine nucleotide translocase (ANT) in the transfer of ADP and ATP into and out of the mitochondria. Results: Here, we use quantitative immunogold transmission electron microscopy to show that in Drosophila melanogaster indirect flight muscles (IFM), ANT is present in the mitochondria as well as throughout the myofibril. To confirm this unexpected result, we created a transgenic line that expresses a chimeric GFP-ANT protein and used an anti-GFP antibody to determine the intracellular distribution of the fusion protein in the IFM. Similar to results obtained with anti-ANT, the fusion GFP-ANT protein is detected in myofibrils and mitochondria. We confirmed the absence of arginine kinase from IFM mitochondria and show that its sarcomeric (i.e., intramyofibrillar) distribution is similar to that of ANT. Conclusions: These results raise the possibility that direct channeling of nucleotides between mitochondria and myofibrils is assisted by an ANT protein thereby circumventing the need for a phosphagen shuttle in the IFM. The myofibrillar ANT may represent a unique adaptation in the muscles that require efficient exchange of nucleotides between mitochondria and myofibrils.

Methylthioadenosine (MTA) Rescues Methylthioadenosine Phosphorylase (MTAP)-Deficient Tumors from Purine Synthesis Inhibition <i>in Vivo</i>via Non-Autonomous Adenine Supply

Methylthioadenosine phosphorylase, (MTAP) is a key enzyme in the adenine and methionine salvage pathways. MTAP is encoded on human chromosome 9p21 in close proximity to the p16INK4a and p14ARF tumor suppressor genes and is frequently co-deleted with p16INK4a in many cancers. Deletion of MTAP has been reported to create a reliance of MTAP–/– tumors on de novo purine synthesis to maintain adequate pools of AMP, leading to increased sensitivity to purine synthesis inhibitors, such as L-alanosine. The ‘Achilles heel’ created by the loss of MTAP in cancer cells provides a unique therapeutic opportunity whereby MTAP–/– tumors could be selectively targeted with purine synthesis inhibitors and normal tissues could be preferentially rescued with MTAP substrates, such as MTA. We demonstrate that, in contrast to published literature, MTAP–/– cells are not more sensitive to inhibition of de novo purine synthesis than MTAP+/+ cells. Although MTA can preferentially rescue MTAP+/+ cells from purine-synthesis inhibitor toxicity in vitro, MTA protects cells of both genotypes from L-alanosine equivalently in vivo. Our data demonstrate that in vivo, adenine salvaged from plasma and adjacent tissues is sufficient to protect MTAP–/– tumors from the effects of purine synthesis inhibitors. These results suggest targeting MTAP–/– tumors with de novo purine synthesis inhibitors is unlikely to provide significant benefit over other therapeutic strategies and may explain, at least in part, the lack of efficacy of L-alanosine in clinical trials.

Studies on Synthesis of Stationary Phase Containing Nicotinamide Adenine Dinucleotide(NAD) Bonded to Phospholipid-Coated Aminated Silica for HPLC

Recently biospecific affinity chromatography has been widely used for the separation and purification of various enzymes and nucleic acids. In this paper, a series of synthetic reactions of solid-liquid phase were carried out on silica surface, using a macroporous(30 mu m), microspherical silica (8 mu m) as the matrix and gamma-aminopropyltriethoxysilane as the activating agent, the nicotinamide adenine dinucleotide(NAD) was bonded through its amino groups to the carboxylic groups of linked phospholipid which was bonded covalently on aminated support. The bonded stationary phase has high thermal stability, and could be used to separate of nucleotides with good resolution.

Nicotinamide Adenine Dinucleotide and Adenosine Triphosphate Oscillations Caused by Gradual Entry of Substrates within Mitochondria

Nicotinamide adenine dinucleotide (NAD) oscillation was observed when the isolated mitochondria were immersed in a pyruvate solution. In addition, when an adenosine diphosphate (ADP) was added to the mitochondrial suspension containing pyruvate, adenosine triphosphate (ATP) oscillation was observed as well as NADH oscillation. At this time, the pH within mitochondria also oscillated. It was found that the oscillatory reaction of NADH caused by the membrane permeation of pyruvate continues, causing the oscillation of NADH and H+ in the subsequent reactions. The pH oscillation led to the ATP oscillation. It is considered that the oscillatory reaction caused by the gradual entry of pyruvate into mitochondria was thought to be carried over to both the citric acid cycle and the respiratory chain, ultimately leading to the ATP oscillation in oxidative phosphorylation. Similarly, it was found that membrane permeation of malate causes the gradual occurrence of NADH, at which point NADH oscillates, followed by an oscillatory reaction of the respiratory chain, and finally ATP oscillation. It was found that the oscillations of NADH and ATP occur without going through the citric acid cycle. Oscillations of NADH and other intermediates in both the citric acid cycle and respiratory chain were also confirmed by experiments using semipermeable membranes. These results support our hypothesis that the gradual entry of the substrate by membrane permeation triggers an oscillatory reaction of the enzyme, which is also carried over to subsequent reactions.

Polymerase-tautomeric Model for Untargeted Delayed Base Substitution Mutations Formation during Error-prone and SOS Replication of Double-stranded DNA Containing Thymine and Adenine in Some Rare Tautomeric Forms

Polymerase-tautomeric model for untargeted delayed base substitution mutations is proposed.Structural analysis of bases insertion showed that any canonical bases may be inserted opposite rare tautomeric forms of thymine T3*,adenines A2*and A4*so that between them hydrogen bonds are formed.Canonical adenine and cytosine can be incorporated opposite canonical thymine only.Canonical thymine and guanine can be incorporated opposite canonical adenine only.If in the synthesis of DNA containing rare tautomeric forms of thymine T3*,adenines A2*and A4*,involved DNA polymerases with relatively high fidelity of synthesis,mutations not appear.However,if further DNA synthesis will involve DNA polymerases having a low fidelity of synthesis,there may be base substitution mutations.It was shown that the conclusion made in the Tomasetti and Vogelstein cancer risk model that the formation of about 67%of all mutations was not caused by exposure to any mutagens is erroneous.