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1.
J Hazard Mater ; 443(Pt B): 130375, 2023 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-36444067

RESUMO

Cr(VI) contaminated water usually contains other contaminants like engineered nanomaterials (ENMs). During the process of microbial treatment, the inevitable interaction of Cr(VI), ENMs, and microorganisms probably determines the efficiency of Cr(VI) biotransformation, however, the corresponding information remains elusive. This study investigated the interaction of ZnO nanoparticles (NPs), Cr(VI), and Pannonibacter phragmitetus BB (hereafter BB), which changed the process of microbial Cr(VI) reduction. ZnO NPs inhibited Cr(VI) reduction, but had no effect on bacterial viability. In particular, Cr(VI) induced BB to produce organic acids and to drive Zn2+ dissolution from ZnO NPs inside and outside of cells. The dissolved Zn2+ not only promoted Cr(VI) reduction to Cr(V)/Cr(IV) by strengthening sugar metabolism and inducing increase in NAD(P)H production, but also hindered Cr(V)/Cr(IV) transformation to Cr(III) through down-regulating Cr(VI) reductase genes. A novel bacterial driven ROS scavenging mechanism leading to the inhibition of Cr(VI) reduction was elucidated. Specifically, the accumulated Cr(VI) and Cr(V)/Cr(IV) formed a redox dynamic equilibrium, which triggered the disproportionation of superoxide radicals mimicking superoxide dismutase through the flip-flop of Cr(VI) and Cr(V)/Cr(IV) in bacterial cells. This study provided a realistic insight into design the applicability of biological remediation technology for Cr(VI) contaminant and evaluating environmental risks of ENMs.


Assuntos
Nanopartículas , Nanoestruturas , Óxido de Zinco , Espécies Reativas de Oxigênio , Óxido de Zinco/toxicidade , NAD
2.
Dis Model Mech ; 16(5)2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36374036

RESUMO

Nicotinamide adenine dinucleotide (NAD) is a key metabolite synthesised from vitamin B3 or tryptophan. Disruption of genes encoding NAD synthesis enzymes reduces NAD levels and causes congenital NAD deficiency disorder (CNDD), characterised by multiple congenital malformations. SLC6A19 (encoding B0AT1, a neutral amino acid transporter), represents the main transporter for free tryptophan in the intestine and kidney. Here, we tested whether Slc6a19 heterozygosity in mice limits the tryptophan available for NAD synthesis during pregnancy and causes adverse pregnancy outcomes. Pregnant Slc6a19+/- mice were fed diets depleted of vitamin B3, so that tryptophan was the source of NAD during gestation. This perturbed the NAD metabolome in pregnant Slc6a19+/- females, resulting in reduced NAD levels and increased rates of embryo loss. Surviving embryos were small and exhibited specific combinations of CNDD-associated malformations. Our results show that genes not directly involved in NAD synthesis can affect NAD metabolism and cause CNDD. They also suggest that human female carriers of a SLC6A19 loss-of-function allele might be susceptible to adverse pregnancy outcomes unless sufficient NAD precursor amounts are available during gestation. This article has an associated First Person interview with the first author of the paper.


Assuntos
Sistemas de Transporte de Aminoácidos Neutros , Anormalidades Congênitas , NAD , Animais , Feminino , Camundongos , Gravidez , Sistemas de Transporte de Aminoácidos Neutros/genética , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Heterozigoto , Rim/metabolismo , NAD/deficiência , Niacinamida , Triptofano/genética , Triptofano/metabolismo , Anormalidades Congênitas/genética
3.
Reproduction ; 165(1): 103-111, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36269127

RESUMO

In brief: Oocyte quality and its NAD+ level decrease with time during in vitro culture. This study shows that nicotinamide riboside (NR) supplementation improves early embryonic development potential in post-ovulatory oocytes by decreasing the reactive oxygen species (ROS) levels and reducing DNA damage and apoptosis which could potentially increase the success rate of assisted reproductive technology (ART). Abstract: The quality of post-ovulatory oocytes deteriorates over time, impacting the outcome of early embryonic development during human ART. We and other groups have found that NAD+, a prominent redox cofactor and enzyme substrate, decreases in both aging ovaries and oocytes. In this study, we found that the NAD+ levels decreased in the post-ovulatory mouse oocytes during in vitro culture and this decrease was partly prevented by NR supplementation. NR treatmenty restored MII oocyte quality and enhanced the early embryonic development potential of post-ovulatory oocytes via alleviating mitochondrial dysfunction and maintaining normal spindle/chromosome structure. Also, treatment with NR decreased ROS levels and reduced DNA damage and apoptosis in post-ovulatory oocytes. Taken together, our findings indicated that NR supplementation increases the oocyte quality and early embryonic development potential in post-ovulatory oocytes which could potentially increase the success rate of ART.


Assuntos
NAD , Oócitos , Camundongos , Humanos , Animais , Espécies Reativas de Oxigênio , Suplementos Nutricionais
4.
Biosens Bioelectron ; 220: 114826, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36371959

RESUMO

Nicotinamide riboside (NR) is a form of vitamin B3 and is one of the most studied compounds for the restoration of cellular NAD+ levels demonstrating clinical potential in many metabolic and age-related disorders. Despite its wide commercial availability as a powerful nutraceutical, our understanding of NR uptake by different cells and tissues is greatly limited by the lack of noninvasive in vivo imaging tools limiting its clinical translation. Here, we report the development and validation of a bioluminescent NR uptake probe (BiNR) for non-invasive longitudinal imaging of NR uptake both in vitro and in vivo. In addition, we optimized an assay that allows monitoring of NR flux without the need to transfect cells with the luciferase gene, enabling the use of the BiNR probe in clinical samples, as demonstrated with human T cells. Lastly, we used BiNR to investigate the role of NR uptake in cancer prevalence and metastases formation in triple negative breast cancer (TNBC) animal model. Our results demonstrate that NR supplementation results in a significant increase in cancer prevalence and metastases of TNBC to the brain. These results outline the important role of powerful nutraceuticals like NR in cancer metabolism and the need to personalize their use in certain patient populations.


Assuntos
Técnicas Biossensoriais , Neoplasias de Mama Triplo Negativas , Animais , Humanos , NAD , Niacinamida/metabolismo , Compostos de Piridínio
5.
Biosens Bioelectron ; 220: 114891, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36379173

RESUMO

The interest in ketone bodies (KBs) has intensified recently as they play significant roles in healthcare, nutrition, and wellness applications. We present a disposable electrochemical sensing strip for rapid decentralized detection of ß-hydroxybutyrate (HB), one of the dominant physiological KBs, in saliva. The new salivary enzymatic HB sensor strip relies on a gold-coated screen-printed carbon electrode modified with a reagent layer containing toluidine blue O (TBO mediator), ß-hydroxybutyrate dehydrogenase (HBD enzyme), and the HBD cofactor nicotinamide adenine dinucleotide (NAD+ coenzyme), along with carbon nanotubes (CNTs) and chitosan (Chit) for enhancing the sensor's sensitivity and for encapsulating the enzyme and its cofactor, respectively. The systematic optimization resulted in an attractive analytical performance, with a rapid response time within 60 s, a wide HB dynamic detection range from 0.1 to 3.0 mM along with a low limit of detection (50 µM HB) in an artificial saliva medium. The strip displays high selectivity for HB over acetoacetate (AcAc) and other interferences (i.e., acetaminophen, ascorbic acid, glucose, lactic acid, and uric acid), good reproducibility, and high stability towards temperature or pH effects. The new disposable sensing strip system, coupled with a hand-held electrochemical analyzer, showed rapid HB monitoring in human saliva samples collected from healthy volunteers, with similar temporal profiles to those obtained in parallel capillary blood measurements in response to the intake of keto supplements. This strip enables efficient, reliable, and near real-time salivary HB detection to track non-invasively the dynamics of HB concentrations after intaking commercial supplements towards diverse healthcare and nutrition applications.


Assuntos
Técnicas Biossensoriais , Nanotubos de Carbono , Humanos , Corpos Cetônicos , Técnicas Biossensoriais/métodos , Reprodutibilidade dos Testes , Eletrodos , NAD , Atenção à Saúde , Técnicas Eletroquímicas
6.
J Affect Disord ; 320: 29-36, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36181911

RESUMO

BACKGROUND: The antidepressant effects of ketamine in patients with anxious depression (AD) remain unclear. Functional connectivity (FC) differences in the amygdala have been linked to depression improvement after ketamine treatment in depressed patients, but their role in AD patients is uncertain. We investigated the correlation between depression improvement after ketamine treatment and amygdala FC in AD patients. METHODS: Thirty-one AD patients and 18 non-anxious depression (NAD) patients received six intravenous ketamine infusions (0.5 mg/kg) over two weeks. AD patients were further divided into responders (defined as a ≥50% MADRS total score reduction on day 13) and non-responders. The FC of the amygdala subregions, including the laterobasal amygdala (LBA), centromedial amygdala (CMA), and superficial amygdala, were compared between the groups. Receiver operating characteristic curves were used to predict treatment response after ketamine infusions. RESULTS: The baseline FC difference in the left LBA and the left precuneus between responders and non-responders among AD patients was found to be associated with depression improvement and was a significant predictor of treatment response to ketamine. A marked reduction in baseline LBA-precuneus FC after ketamine infusion was observed in responders. Unlike in patients with NAD, a lower right CMA-right middle temporal gyrus FC was found in AD patients. LIMITATIONS: The sample size is rather small. CONCLUSIONS: Our findings may suggest that amygdala FC is a significant predictor of treatment response to ketamine infusions in patients with AD. Further studies exploring the potential antidepressant mechanisms of ketamine may aid in the treatment of AD patients.


Assuntos
Transtorno Depressivo Resistente a Tratamento , Ketamina , Humanos , Ketamina/uso terapêutico , Depressão , NAD , Antidepressivos/uso terapêutico , Tonsila do Cerebelo/diagnóstico por imagem , Infusões Intravenosas , Transtorno Depressivo Resistente a Tratamento/diagnóstico por imagem , Transtorno Depressivo Resistente a Tratamento/tratamento farmacológico
7.
J Environ Sci (China) ; 124: 952-962, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36182197

RESUMO

The long-term impact of fulvic acid (FA) on partial nitritation (PN) system was initially examined in this study. The obtained results revealed that the FA lower than 50 mg/L had negligible effect on the nitrite accumulation rate (NAR nearly 100%) and ammonium removal rate (ARR 56.85%), while FA over 50 mg/L decreased ARR from 56.85% to 0.7%. Sludge characteristics analysis found that appropriate FA (<50 mg/L) exposure promoted the settling performance and granulation of PN sludge by removing Bacteroidetes and accumulating Chloroflexi. The analysis of metagenomics suggested that the presence of limited FA (0-50 mg/L) stimulated the generation of NADH, which favors the denitrification and nitrite reduction. The negative impact of FA on the PN system could be divided into two stages. Initially, limited FA (50-120 mg/L) was decomposed by Anaerolineae to stimulate the growth and propagation of heterotrophic bacteria (Thauera). Increasing heterotrophs competed with AOB (Nitrosomonas) for dissolved oxygen, causing AOB to be eliminated and ARR to declined. Subsequently, when FA dosage was over 120 mg/L, Anaerolineae were inhibited and heterotrophic bacteria reduced, resulting in the abundance of AOB recovered. Nevertheless, the ammonium transformation pathway was suppressed because genes amoABC and hao were obviously reduced, leading to the deterioration of reactor performance. Overall, these results provide theoretical guidance for the practical application of PN for the treatment of FA-containing sewage.


Assuntos
Compostos de Amônio , Esgotos , Compostos de Amônio/metabolismo , Bactérias/genética , Bactérias/metabolismo , Benzopiranos , Reatores Biológicos/microbiologia , Metagenômica , NAD/metabolismo , Nitritos/metabolismo , Nitrogênio/metabolismo , Oxirredução , Oxigênio/metabolismo , Esgotos/microbiologia
8.
Gene ; 851: 146996, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36283603

RESUMO

Glutamate synthase (GOGAT) is a key enzyme in glutamine synthetase (GS)/GOGAT cycle and at the hub of carbon and nitrogen metabolism, catalyzing the formation of glutamate from α-oxoglutarate and glutamine. In this study, members of GOGAT family in Populus trichocarpa were identified and analyzed by bioinformatics. The four PtGOGATs were divided into two subgroups: subgroup A (Fd-GOGAT1 and Fd-GOGAT2) and subgroup B (NADH-GOGAT1 and NADH-GOGAT2). Many important elements have been identified in the promoters of different PtGOGATs, including hormone- and light-responsive elements. Meanwhile, the transcript levels of PxGOGATs were affected by light and diurnal cycle. Quantitative real-time PCR showed PxFd-GOGATs and PxNADH-GOGATs were mainly expressed in leaves and roots in Populus × xiaohei T. S. Hwang et Liang, respectively. Under elevated CO2, PxGOGATs were suppressed in all tissues except the stem. And PxFd-GOGATs and PxNADH-GOGATs were strongly induced by nitrogen in leaves and roots, respectively. In addition, PxGOGATs were stimulated significantly in roots in response to NH4+and glutamine directly. Our results provide new insights about GOGATs in poplar and their expression patterns under exogenous substances, to lay molecular basis for studying gene function and provide a reference for exploring putative roles of GOGATs in carbon-nitrogen balance.


Assuntos
Glutamato Sintase , Populus , Glutamato Sintase/genética , Populus/genética , Populus/metabolismo , Nitrogênio/farmacologia , Nitrogênio/metabolismo , Carbono/metabolismo , Glutamina/metabolismo , NAD/genética , NAD/metabolismo , Regulação da Expressão Gênica de Plantas
9.
Med Gas Res ; 13(2): 72-77, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36204786

RESUMO

Diabetic peripheral neuropathy (DPN) is a complex disorder caused by long-standing diabetes. Oxidative stress was considered the critical creed in this DPN pathophysiology. Hydrogen has antioxidative effects on diabetes mellitus and related complications. However, there is still no concern on the beneficial effects of hydrogen in DPN. This paper aimed to evaluate the effects of exogenous hydrogen to reduce the severity of DPN in streptozotocin-induced diabetic rats. Compared with hydrogen-rich saline treatment, hydrogen inhalation significantly reduced blood glucose levels in diabetic rats in the 4th and 8th weeks. With regard to nerve function, hydrogen administration significantly attenuated the decrease in the velocity of motor nerve conduction in diabetic animals. In addition, hydrogen significantly attenuated oxidative stress by reducing the level of malondialdehyde, reactive oxygen species, and 8-hydroxy-2-deoxyguanosine and meaningfully enhanced the antioxidant capability by partially restoring the activities of superoxide dismutase. Further studies showed that hydrogen significantly upregulated the expression of nuclear factor erythroid-2-related factor 2 and downstream proteins such as catalase and hemeoxygenase-1 in the nerves of diabetic animals. Our paper showed that hydrogen exerts significant protective effects in DPN by downregulating oxidative stress via the pathway of nuclear factor erythroid-2-related factor 2, which suggests its potential value in clinical applications.


Assuntos
Diabetes Mellitus Experimental , Neuropatias Diabéticas , Fármacos Neuroprotetores , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Glicemia , Catalase/metabolismo , Catalase/farmacologia , Catalase/uso terapêutico , Desoxiguanosina/metabolismo , Desoxiguanosina/farmacologia , Desoxiguanosina/uso terapêutico , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/tratamento farmacológico , Neuropatias Diabéticas/tratamento farmacológico , Neuropatias Diabéticas/metabolismo , Hidrogênio , Malondialdeído , NAD/metabolismo , NAD/farmacologia , NAD/uso terapêutico , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Estresse Oxidativo , Ratos , Espécies Reativas de Oxigênio , Estreptozocina , Superóxido Dismutase/metabolismo , Superóxido Dismutase/farmacologia , Superóxido Dismutase/uso terapêutico
10.
Enzyme Microb Technol ; 162: 110122, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36103798

RESUMO

ß-Nicotinamide mononucleotide (NMN) is an important precursor in the synthesis of nicotinamide adenine dinucleotide (NAD+) and confers multiple health benefits, resulting in the rapid growth of NMN market capacity in the fields of food and health care. To overcome the drawbacks of NMN production by the existing chemical or microbial fermentation method, there is an urgent need to develop a prospective NMN production strategy with low cost, low pollution, and high yield. In this study, we demonstrated an artificial in vitro multi-enzyme cascade biocatalysis using starch and nicotinamide (Nam) as substrates for the synthesis of NMN in one-pot. This multi-enzyme cascade reaction was optimized in terms of pH value, buffer concentration, inorganic phosphate concentration, enzyme composition, and phosphoenolpyruvate concentration. Under optimized conditions, a high molar yield of 87.8% for NMN was achieved using 3.2 mM Nam as substrate, and a molar yield of 55.37% for NMN was also achieved under the initial Nam concentration of 9.21 mM. This in vitro enzymatic platform provides an environmental friendliness biomanufacturing technology for the production of NMN, showing a highly promising alternative approach for NMN production.


Assuntos
Niacinamida , Mononucleotídeo de Nicotinamida , Mononucleotídeo de Nicotinamida/metabolismo , Biocatálise , Amido , Estudos Prospectivos , NAD/metabolismo
11.
J Sci Food Agric ; 103(1): 450-456, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36205212

RESUMO

BACKGROUND: Nicotinamide mononucleotide (NMN), a key intermediate of nicotinamide adenine dinucleotide, plays an important in anti-aging and disease. Lactococcus lactis, an important probiotic lactic acid bacteria (LAB), has shown great potential for the biosynthesis of NMN, which will significantly affect the probiotic effects of the dairy products. RESULTS: We used the CRISPR/nCas9 technique to knockout nadR gene of L. lactis NZ9000 to enhance the accumulation of NMN by 61%. The nadE* gene from Francisella tularensis with codon optimization was heterologous in L. lactis NZ9000ΔnadR and has a positive effect on NMN production. Combined with optimization of the concentration of substrate nicotinamide, a final intracellular NMN titer was 2289 µmol L-1  mg-1 with 10 g L-1 nicotinamide supplement, which was 5.7-fold higher than that of the control. The transcription levels of key genes (pncA, nadD and prs1) involved in NMN biosynthesis were up-regulated by more than two-fold, indicating that the increase of NMN titer was attributed to FtnadE* heterologous expression. CONCLUSION: Our study provides a better understanding of the NMN biosynthesis pathway in L. lactis, and can facilitate NMN production in LAB via synthetic biology approaches. © 2022 Society of Chemical Industry.


Assuntos
Lactococcus lactis , Mononucleotídeo de Nicotinamida , Mononucleotídeo de Nicotinamida/metabolismo , Mononucleotídeo de Nicotinamida/farmacologia , Lactococcus lactis/genética , Lactococcus lactis/metabolismo , NAD/metabolismo , Niacinamida/metabolismo
12.
Methods Mol Biol ; 2589: 95-110, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36255620

RESUMO

Sirtuins are identified as NAD+-dependent class III histone deacetylases (HDAC) and are involved in a variety of cellular activities, including energy metabolism, DNA repair, epigenetics, gene expression, cell proliferation, differentiation, and survival. Using genetically modified model organisms, sirtuins are proved to be one of the most conserved aging-regulatory and longevity-promoting genes/pathways among species. Of the seven sirtuins, SIRT7 is the only sirtuin that localizes in the nucleolus. SIRT7 senses endogenous and environmental stress to maintain physiological homeostasis. Sirt7 deficient and transgenic mice provide a useful tool to understand the mechanisms of aging and related pathologies. In this chapter, we summarized the most widely applied methods to understand the physiopathological function of SIRT7 in mice.


Assuntos
Sirtuínas , Camundongos , Animais , Sirtuínas/genética , Sirtuínas/metabolismo , NAD/metabolismo , Envelhecimento/genética , Epigênese Genética , Metabolismo Energético
13.
Methods Mol Biol ; 2589: 411-428, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36255640

RESUMO

Protein lysine acylation represents one of the most common post-translational modifications. Obviously, highly reactive metabolic intermediates, like thioesters and mixed anhydrides between phosphoric acid and organic acids, modify lysine residues spontaneously. Additionally, enzymes using acyl-CoAs as co-substrates transfer the acyl residue specifically to defined sequences within proteins. The counteracting enzymes are called histone deacetylases (HDACs), releasing the free lysine side chain. Such enzymatic activities are involved in different cellular processes like tumor progression, immune response, regulation of metabolism, and aging. Modulators of such enzymatic activities represent valuable tools in drug discovery. Therefore, direct and continuous assays to monitor enzymatic activity of HDACs are needed. Here we describe different assay formats allowing both monitoring of Zn2+-dependent HDACs via UV-Vis-spectroscopy and NAD+-dependent HDACs (sirtuins) by fluorescence-based assay formats. Additionally, we describe methods enabling efficient screening of HDAC-inhibitors via fluorescence displacement assays.


Assuntos
Histonas , Sirtuínas , Lisina/metabolismo , NAD/metabolismo , Histona Desacetilases/metabolismo , Sirtuínas/metabolismo , Ácidos Fosfóricos/metabolismo , Anidridos
14.
Parasitol Int ; 92: 102695, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36349608

RESUMO

The mitochondria of adult and plerocercoid Spirometra mansoni were characterized in isolated mitochondria and in situ by electron microscopic histochemistry with special attention to the respiratory chain. Although the specific activities of the constituent enzyme complexes of succinate oxidase are fairly similar in adult and plerocercoid mitochondria, those of succinate oxidase and NADH-FRD are approximately 4- and 25-fold higher in adult mitochondria than in plerocercoid mitochondria, respectively. Quinone analysis by high performance liquid chromatography and mass spectrometry showed that adult and plerocercoid mitochondria contained both rhodoquinone-10 and ubiquinone-10 at concentrations of 4.98 and 0.106 nmol mg-1 for adult, and 0.677 and 0.137 nmol mg-1 for plerocercoid, respectively. Inhibition studies on the succinate-oxidase system of adult mitochondria showed that they possessed both cyanide-sensitive and -insensitive succinate oxidases, the latter of which produces hydrogen peroxide. Adult mitochondria, when NADH was used as a substrate, were shown to produce hydrogen peroxide, and the production of hydrogen peroxide decreased to undetectable levels in the presence of fumarate. The specific activities of NADH-fumarate reductase and cytochrome c oxidase were significantly higher in mature proglottids than in immature and gravid proglottids. Isopycnic density-gradient centrifugation analyses and in situ electron microscopic histochemistry revealed that both adult and plerocercoid mitochondria were heterogeneous in terms of respiratory function and physicochemical properties. The physiological significance of adult and plerocercoid mitochondria is discussed in relation to the oxygen tension of their parasitic habitats.


Assuntos
Plerocercoide , Spirometra , Animais , Peróxido de Hidrogênio , Anaerobiose , NAD , Mitocôndrias , Succinatos
15.
Sci Total Environ ; 856(Pt 1): 159147, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36183769

RESUMO

Denitrification is the key driving force of nitrogen cycle in surface water and plays an important role in eutrophication water remediation. Compared with some other common carbon sources, such as glucose and sodium acetate, polyhydroxyalkanoates (PHAs) were found to have the distinguished advantages in screening specific denitrifying bacteria of natural surface water bodies. In this study, the large ensembles of taxa were obtained from surface water samples and then sub-cultured with PHA or glucose as the sole carbon source. The microbial community that could be screened by PHA was identified, and the environmental functions of these bacteria were analyzed. At the genus level, the main communities regulated by PHA included Pseudomonas (56.30 %), Acinetobacter (27.75 %), Flavobacterium (10.19 %) and Comamonas (3.14 %), which all had good denitrification ability. The changes in carbon source, nitrogen source and biomass (expressed by DNA) were simultaneously monitored when culturing the model strain (P. stuzeri) with PHA or glucose. Compared with the glucose group, less PHA was consumed to remove the same amount of nitrate within a shorter incubation time, and there was no significant difference in bacterial growth with PHA or glucose as the carbon source (glucose:ΔN:ΔC:ΔDNA = 1:18:0.072; PHA:ΔN:ΔC:ΔDNA = 1:11:0.063). PHA improved the denitrification efficiency by increasing the expression of NarGHI, NirB, NirK and NorB, i.e., the key enzymes in the denitrification process. In addition, PHA accelerated the assimilating rate of extracellular nitrate by bacteria through increasing the expression of NarK. Finally, PHA-regulated electron transfer during denitrification was studied by observing the changes in NADH and NAD+. PHA could use a large proportion of NADH to offer electrons for denitrification, which increased the rate of denitrification. Improved mechanistic insights into the PHA-enhanced denitrification capacity of the microbial community can provide novel options for the in-situ remediation of eutrophic surface water.


Assuntos
Microbiota , Poli-Hidroxialcanoatos , Poli-Hidroxialcanoatos/metabolismo , Desnitrificação , Elétrons , Nitratos , NAD/metabolismo , Nitrogênio , Carbono/metabolismo , Bactérias/metabolismo , Glucose , Água
16.
Methods Mol Biol ; 2554: 123-139, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36178624

RESUMO

Saturation transfer difference (STD) nuclear magnetic resonance (NMR) spectroscopy is an established technique for detecting and characterizing the binding of small molecules, such as metabolites, to biological macromolecules like proteins and nucleic acids. STD NMR allows detection of binding in complex mixtures of potential ligands, which is often used for library screening in the pharmaceutical industry but may also be beneficial for binding studies with metabolite mixtures. The nature of the ligand is normally restricted to small molecules in terms of NMR spectroscopy, and the size of the macromolecule on the other side should be larger than 10-15 kDa. This technique is especially applicable to detecting binders of intermediate to low affinity with the dissociation constant (KD) above 1 µM. In this chapter, we focus on recent developments and the applications of STD NMR to studying interactions of natural products and metabolites, in particular. The reader is also referred to excellent reviews of the field and the literature cited therein. This chapter also provides a detailed experimental protocol for performing the STD NMR measurement based on the example of the subunit A of the Na+-transporting NADH/ubiquinone oxidoreductase (Na+-NQR) from V. cholerae interacting with its natural quinone substrate and inhibitors.


Assuntos
Produtos Biológicos , Ácidos Nucleicos , Vibrio cholerae , Misturas Complexas , Ligantes , Espectroscopia de Ressonância Magnética/métodos , NAD/metabolismo , Ressonância Magnética Nuclear Biomolecular/métodos , Ácidos Nucleicos/metabolismo , Oxirredutases/metabolismo , Ligação Proteica , Proteínas/química , Ubiquinona/metabolismo , Vibrio cholerae/metabolismo
17.
Birth Defects Res ; 114(20): 1313-1323, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36453269

RESUMO

BACKGROUND: Nicotinamide adenine dinucleotide (NAD+) depletion is associated with numerous diseases in humans. Recently it was revealed that genetic blockage of the NAD+ synthesis pathway in humans causes birth defects in multiple organ systems and miscarriage. Additionally, mice with NAD+ deficiency created through dietary restriction of tryptophan and vitamin B3 were shown to have congenital anomalies affecting virtually every organ system along with miscarriage. Perturbations in NAD+/NADH affect mechanisms of teratogenesis presented by Wilson and others, including genetic alterations, altered energy sources, and lack of precursors and substrates needed for biosynthesis. METHODS: Medical literature was evaluated to demonstrate how perturbations in NAD+/NADH affect mechanisms of teratogenesis. In addition, literature describing several different teratogens of various types (infectious, physical, maternal health factors, drugs) was reviewed showing the impact of these teratogens on NAD+ and NAD+/NADH ratios. RESULT: Many teratogens affect NAD+ by altering its metabolism, decreasing its intracellular availability, or decreasing its production, which in turn is a plausible mechanism for the creation of birth defects. CONCLUSION: Looking at teratogens through the lens of their impact on NAD+ could provide valuable insight into the mechanism by which some teratogens cause birth defects and miscarriage.


Assuntos
Aborto Espontâneo , Cristalino , Teratogênese , Humanos , Feminino , Gravidez , Animais , Camundongos , NAD , Teratógenos/toxicidade
18.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 34(5): 518-521, 2022 Aug 17.
Artigo em Chinês | MEDLINE | ID: mdl-36464259

RESUMO

OBJECTIVE: To investigate the genetic variations of Toxascaris leonina isolates from different hosts in Jiuquan City, Gansu Province. METHODS: The mitochondrial sequences of partial mitochondrial nicotinamide adenine dinucleotide dehydrogenase subunit 1 (pnad1) and pnad5 of eleven T. leonina isolates from domestic dogs, foxes and pet dogs in Jiuquan City, Gansu Province, were amplified using PCR, and the amplification product was sequenced. The genetic variations of pnad1 and pnad5 genes in T. leonina isolates were analyzed. RESULTS: The sequences of T. leonina pnad1 and pnad5 genes measured 530 bp and 550 bp in size, respectively. The nucleotide sequence homology was 99.4% to 100.0% for T. leonina pnad1 gene and 99.5% to 99.8% for T. leonina pnad5 gene, and the sequences of T. leonina pnad1 and pnad5 genes shared 99.2% to 99.9% and 99.1% to 99.9% with corresponding sequences of known T. leonina isolates. In addition, there were 19 and 24 polymorphic sites detected in the sequences of T. leonina pnad1 and pnad5 genes, with 10 and 9 haplotypes, haplotype diversity of 0.982 and 0.964 and nucleotide diversity of 0.039 4 and 0.034 2, respectively. Phylogenetic analysis based on pnad1 and pnad5 gene sequences showed that the eleven T. leonina isolates and known T. leonina isolates were clustered into the same branch with a random distribution, which were close to the branch where Toxocara canis was clustered, and far from the branch where other Ascaris species were clustered. CONCLUSIONS: There is a minor genetic variation in pnad1 and pnad5 genes of T. leonina isolates from different hosts in Jiuquan City, Gansu Province, and the pnad1 gene is more suitable as a molecular marker than pnad5 gene for analysis of genetic variations in T. leonina.


Assuntos
Raposas , NAD , Cães , Animais , Toxascaris/genética , Filogenia , Variação Genética , Oxirredutases
19.
Front Endocrinol (Lausanne) ; 13: 1037969, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36465631

RESUMO

Background: This study aimed to evaluate the relationship between thyroid-related hormones and vascular complications in type 2 diabetes mellitus (T2DM) patients with euthyroidism. Methods: We enrolled 849 patients with T2DM after screening out the ineligible. Multivariate logistic regression was used to analyze the relationship between fT3, fT4, the fT3/fT4 ratio, thyroid-stimulating hormone, and diabetic vascular complications. Spearman correlation analysis was used to determine the correlation between thyroid-related hormones and vascular complications. Results: In this cross-sectional study of T2DM, 538 patients with carotid atherosclerosis (CA) and 299 patients with diabetic peripheral neuropathy (DPN). The prevalence of DPN was negatively correlated with fT3 and the fT3/fT4 ratio but positively correlated with fT4 (all P<0.01). At the same time, the odds ratio for DPN decreased with increasing fT3 (T1: reference; T2: OR: 0.689, 95%CI: 0.477, 0.993; T3: OR: 0.426, 95% CI: 0.286, 0.633, all P<0.05) and fT3/fT4 ratio (T1: reference; T2: OR: 0.528, 95% CI: 0.365, 0.763; T3: OR: 0.413, 95% CI: 0.278, 0.613, all P<0.001). In terms of sensitivity and specificity, fT4 was found to be 39.5% and 71.4% accurate, respectively, with a 95% CI of 0.531-0.611. Conclusions: We found a negative correlation between fT3 and fT3/fT4 ratio and the number of individuals with DPN, and a positive correlation between fT4 and the prevalence of DPN.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Neuropatias Diabéticas , Humanos , Diabetes Mellitus Tipo 2/complicações , Estudos Transversais , NAD , Glândula Tireoide , Hormônios Tireóideos
20.
J Biomed Sci ; 29(1): 102, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36457101

RESUMO

BACKGROUND: yqiC is required for colonizing the Salmonella enterica serovar Typhimurium (S. Typhimurium) in human cells; however, how yqiC regulates nontyphoidal Salmonella (NTS) genes to influence bacteria-host interactions remains unclear. METHODS: The global transcriptomes of S. Typhimurium yqiC-deleted mutant (ΔyqiC) and its wild-type strain SL1344 after 2 h of in vitro infection with Caco-2 cells were obtained through RNA sequencing to conduct comparisons and identify major yqiC-regulated genes, particularly those involved in Salmonella pathogenicity islands (SPIs), ubiquinone and menaquinone biosynthesis, electron transportation chains (ETCs), and carbohydrate/energy metabolism. A Seahorse XFp Analyzer and assays of NADH/NAD+ and H2O2 were used to compare oxygen consumption and extracellular acidification, glycolysis parameters, adenosine triphosphate (ATP) generation, NADH/NAD+ ratios, and H2O2 production between ΔyqiC and SL1344. RESULTS: After S. Typhimurium interacts with Caco-2 cells, yqiC represses gene upregulation in aspartate carbamoyl transferase, type 1 fimbriae, and iron-sulfur assembly, and it is required for expressing ilvB operon, flagellin, tdcABCD, and dmsAB. Furthermore, yqiC is required for expressing mainly SPI-1 genes and specific SPI-4, SPI-5, and SPI-6 genes; however, it diversely regulates SPI-2 and SPI-3 gene expression. yqiC significantly contributes to menD expression in menaquinone biosynthesis. A Kyoto Encyclopedia of Genes and Genomes analysis revealed the extensive association of yqiC with carbohydrate and energy metabolism. yqiC contributes to ATP generation, and the analyzer results demonstrate that yqiC is required for maintaining cellular respiration and metabolic potential under energy stress and for achieving glycolysis, glycolytic capacity, and glycolytic reserve. yqiC is also required for expressing ndh, cydA, nuoE, and sdhB but suppresses cyoC upregulation in the ETC of aerobically and anaerobically grown S. Typhimurium; priming with Caco-2 cells caused a reversed regulation of yiqC toward upregulation in these ETC complex genes. Furthermore, yqiC is required for maintaining NADH/NAD+ redox status and H2O2 production. CONCLUSIONS: Specific unreported genes that were considerably regulated by the colonization-associated gene yqiC in NTS were identified, and the key role and tentative mechanisms of yqiC in the extensive modulation of virulence factors, SPIs, ubiquinone and menaquinone biosynthesis, ETCs, glycolysis, and oxidative stress were discovered.


Assuntos
Salmonella typhimurium , Transcriptoma , Humanos , Salmonella typhimurium/genética , NAD , Ubiquinona , Células CACO-2 , Peróxido de Hidrogênio/farmacologia , Vitamina K 2 , Respiração Celular , Estresse Oxidativo/genética , Trifosfato de Adenosina , Carboidratos
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