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1.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 34(5): 621-629, 2020 May 15.
Artigo em Chinês | MEDLINE | ID: mdl-32410431

RESUMO

Objective: To investigate the effect of nicotinamide mononucleotide adenosyl transferase 3 (NMNAT3) on the mitochondrial function and anti-oxidative stress of rabbit bone marrow mesenchymal stem cells (BMSCs) under oxidative stress in vitro by regulating nicotinamide adenine dinucleotide (NAD +) levels. Methods: The bone marrow of femur and tibia of New Zealand white rabbits were extracted. BMSCs were isolated and cultured in vitro by density gradient centrifugation combined with adherent culture. The third generation cells were identified by flow cytometry and multi-directional induction. Overexpression of NMNAT3 gene was transfected into rabbit BMSCs by enhanced green fluorescent protein (EGFP) labeled lentivirus (BMSCs/Lv-NMNAT3-EGFP), and then the expression of NMNAT3 was detected by real-time fluorescence quantitative PCR (qRT-PCR) and Western blot and cell proliferation by cell counting kit 8 (CCK-8) method. BMSCs transfected with negative lentivirus (BMSCs/Lv-EGFP) and untransfected BMSCs were used as controls. The oxidative stress injury cell model was established by using H 2O 2 to treat rabbit BMSCs. According to the experimental treatment conditions, they were divided into 4 groups: Group A was normal BMSCs without H 2O 2 treatment; untransfected BMSCs, BMSCs/Lv-EGFP, and BMSCs/Lv-NMNAT3-EGFP in groups B, C, and D were treated with H 2O 2 simulated oxidative stress, respectively. The effects of NMNAT3 on the mitochondrial function of BMSCs under oxidative stress [changes of mitochondrial membrane potential, NAD + and adenosine triphosphate (ATP) levels], the changes of anti-oxidative stress ability of BMSCs [reactive oxygen species (ROS) and malondialdehyde (MDA) levels, manganese superoxide dismutase (Mn-SOD) and catalase (CAT) activities], and the effects of BMSCs on senescence and apoptosis [senescence associated-ß-galactosidase (SA-ß-gal) staining and TUNEL staining] were detected after 24 hours of treatment. Results: The rabbit BMSCs were successfully isolated and cultured in vitro. The stable strain of rabbit BMSCs with high expression of NMNAT3 gene was successfully obtained by lentiviral transfection, and the expressions of NMNAT3 gene and protein significantly increased ( P<0.05). There was no significant difference in the trend of cell proliferation compared with normal BMSCs. After treatment with H 2O 2, the function of mitochondria was damaged and apoptosis increased in all groups. However, compared with groups B and C, the group D showed that the mitochondrial function of BMSCs improved, the membrane potential increased, the level of NAD + and ATP synthesis of mitochondria increased; the anti-oxidative stress ability of BMSCs enhanced, the levels of ROS and MDA decreased, and the activities of antioxidant enzymes (Mn-SOD, CAT) increased; and the proportion of SA-ß-gal positive cells and the rate of apoptosis decreased. The differences in all indicators between group D and groups B and C were significant ( P<0.05). Conclusion: NMNAT3 can effectively improve the mitochondrial function of rabbit BMSCs via increasing the NAD + levels, and enhance its anti-oxidative stress and improve the survival of BMSCs under oxidative stress conditions.


Assuntos
Células-Tronco Mesenquimais , Nicotinamida-Nucleotídeo Adenililtransferase , Animais , Células da Medula Óssea , Células Cultivadas , Mitocôndrias , NAD , Mononucleotídeo de Nicotinamida , Nucleotidiltransferases , Estresse Oxidativo , Coelhos
2.
Am J Physiol Cell Physiol ; 318(4): C796-C805, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32049549

RESUMO

Excessive exposure of the eye to ultraviolet B light (UVB) leads to corneal edema and opacification because of the apoptosis of the corneal endothelium. Our previous study found that nicotinamide (NIC), the precursor of nicotinamide adenine dinucleotide (NAD), could inhibit the endothelial-mesenchymal transition and accelerate healing the wound to the corneal endothelium in the rabbit. Here we hypothesize that NIC may possess the capacity to protect the cornea from UVB-induced endothelial apoptosis. Therefore, a mouse model and a cultured cell model were used to examine the effect of NAD+ precursors, including NIC, nicotinamide mononucleotide (NMN), and NAD, on the UVB-induced apoptosis of corneal endothelial cells (CECs). The results showed that UVB irradiation caused apparent corneal edema and cell apoptosis in mice, accompanied by reduced levels of NAD+ and its key biosynthesis enzyme, nicotinamide phosphoribosyltransferase (NAMPT), in the corneal endothelium. However, the subconjunctival injection of NIC, NMN, or NAD+ effectively prevented UVB-induced tissue damage and endothelial cell apoptosis in the mouse cornea. Moreover, pretreatment using NIC, NMN, and NAD+ increased the survival rate and inhibited the apoptosis of cultured human CECs irradiated by UVB. Mechanistically, pretreatment using nicotinamide (NIC) recovered the AKT activation level and decreased the BAX/BCL-2 ratio. In addition, the capacity of NIC to protect CECs was fully reversed in the presence of the AKT inhibitor LY294002. Therefore, we conclude that NAD+ precursors can effectively prevent the apoptosis of the corneal endothelium through reactivating AKT signaling; this represents a potential therapeutic approach for preventing UVB-induced corneal damage.


Assuntos
Apoptose/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , NAD/efeitos dos fármacos , Mononucleotídeo de Nicotinamida/farmacologia , Animais , Morte Celular/efeitos dos fármacos , Células Cultivadas , Células Endoteliais/metabolismo , Epitélio Posterior/efeitos dos fármacos , Epitélio Posterior/metabolismo , Humanos , Camundongos , NAD/metabolismo , Substâncias Protetoras/farmacologia , Coelhos
3.
Nat Chem Biol ; 16(1): 87-94, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31768035

RESUMO

Biological production of chemicals often requires the use of cellular cofactors, such as nicotinamide adenine dinucleotide phosphate (NADP+). These cofactors are expensive to use in vitro and difficult to control in vivo. We demonstrate the development of a noncanonical redox cofactor system based on nicotinamide mononucleotide (NMN+). The key enzyme in the system is a computationally designed glucose dehydrogenase with a 107-fold cofactor specificity switch toward NMN+ over NADP+ based on apparent enzymatic activity. We demonstrate that this system can be used to support diverse redox chemistries in vitro with high total turnover number (~39,000), to channel reducing power in Escherichia coli whole cells specifically from glucose to a pharmaceutical intermediate, levodione, and to sustain the high metabolic flux required for the central carbon metabolism to support growth. Overall, this work demonstrates efficient use of a noncanonical cofactor in biocatalysis and metabolic pathway design.


Assuntos
NADP/química , Mononucleotídeo de Nicotinamida/química , Oxirredução , Biocatálise , Carbono/química , Cromatografia Gasosa , Cicloexanonas/química , Escherichia coli/metabolismo , Cinética , NAD/química , Mononucleotídeo de Nicotinamida/genética , Conformação Proteica , Engenharia de Proteínas , Pseudomonas putida/metabolismo , Ralstonia/metabolismo , Software
4.
Hum Genomics ; 13(1): 65, 2019 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-31823815

RESUMO

BACKGROUND: Chronic alcohol consumption is a significant cause of liver disease worldwide. Several biochemical mechanisms have been linked to the initiation and progression of alcoholic liver disease (ALD) such as oxidative stress, inflammation, and metabolic dysregulation, including the disruption of NAD+/NADH. Indeed, an ethanol-mediated reduction in hepatic NAD+ levels is thought to be one factor underlying ethanol-induced steatosis, oxidative stress, steatohepatitis, insulin resistance, and inhibition of gluconeogenesis. Therefore, we applied a NAD+ boosting supplement to investigate alterations in the pathogenesis of early-stage ALD. METHODS: To examine the impact of NAD+ therapy on the early stages of ALD, we utilized nicotinamide mononucleotide (NMN) at 500 mg/kg intraperitoneal injection every other day, for the duration of a Lieber-DeCarli 6-week chronic ethanol model in mice. Numerous strategies were employed to characterize the effect of NMN therapy, including the integration of RNA-seq, immunoblotting, and metabolomics analysis. RESULTS: Our findings reveal that NMN therapy increased hepatic NAD+ levels, prevented an ethanol-induced increase in plasma ALT and AST, and changed the expression of 25% of the genes that were modulated by ethanol metabolism. These genes were associated with a number of pathways including the MAPK pathway. Interestingly, our analysis revealed that NMN treatment normalized Erk1/2 signaling and prevented an induction of Atf3 overexpression. CONCLUSIONS: These findings reveal previously unreported mechanisms by which NMN supplementation alters hepatic gene expression and protein pathways to impact ethanol hepatotoxicity in an early-stage murine model of ALD. Overall, our data suggest further research is needed to fully characterize treatment paradigms and biochemical implications of NAD+-based interventions.


Assuntos
Perfilação da Expressão Gênica , Hepatopatias Alcoólicas/tratamento farmacológico , Mononucleotídeo de Nicotinamida/uso terapêutico , RNA/genética , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Doença Crônica , Modelos Animais de Doenças , Etanol , Regulação da Expressão Gênica/efeitos dos fármacos , Hepatopatias Alcoólicas/sangue , Hepatopatias Alcoólicas/genética , Metaboloma , Metabolômica , Camundongos Endogâmicos C57BL , Mononucleotídeo de Nicotinamida/farmacologia , Substâncias Protetoras/metabolismo , RNA/metabolismo , Transdução de Sinais/efeitos dos fármacos
5.
Proc Natl Acad Sci U S A ; 116(47): 23822-23828, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31694884

RESUMO

Nicotinamide adenine dinucleotide (NAD+) is a critical coenzyme for cellular energy metabolism. The aim of the present study was to determine the importance of brown and white adipose tissue (BAT and WAT) NAD+ metabolism in regulating whole-body thermogenesis and energy metabolism. Accordingly, we generated and analyzed adipocyte-specific nicotinamide phosphoribosyltransferase (Nampt) knockout (ANKO) and brown adipocyte-specific Nampt knockout (BANKO) mice because NAMPT is the rate-limiting NAD+ biosynthetic enzyme. We found ANKO mice, which lack NAMPT in both BAT and WAT, had impaired gene programs involved in thermogenesis and mitochondrial function in BAT and a blunted thermogenic (rectal temperature, BAT temperature, and whole-body oxygen consumption) response to acute cold exposure, prolonged fasting, and administration of ß-adrenergic agonists (norepinephrine and CL-316243). In addition, the absence of NAMPT in WAT markedly reduced adrenergic-mediated lipolytic activity, likely through inactivation of the NAD+-SIRT1-caveolin-1 axis, which limits an important fuel source fatty acid for BAT thermogenesis. These metabolic abnormalities were rescued by treatment with nicotinamide mononucleotide (NMN), which bypasses the block in NAD+ synthesis induced by NAMPT deficiency. Although BANKO mice, which lack NAMPT in BAT only, had BAT cellular alterations similar to the ANKO mice, BANKO mice had normal thermogenic and lipolytic responses. We also found NAMPT expression in supraclavicular adipose tissue (where human BAT is localized) obtained from human subjects increased during cold exposure, suggesting our finding in rodents could apply to people. These results demonstrate that adipose NAMPT-mediated NAD+ biosynthesis is essential for regulating adaptive thermogenesis, lipolysis, and whole-body energy metabolism.


Assuntos
Adaptação Fisiológica , Tecido Adiposo Marrom/metabolismo , Metabolismo Energético , Homeostase , NAD/biossíntese , Termogênese , Tecido Adiposo Marrom/enzimologia , Animais , Caveolina 1/antagonistas & inibidores , Temperatura Baixa , Citocinas/genética , Jejum , Humanos , Camundongos , Camundongos Knockout , Mononucleotídeo de Nicotinamida/administração & dosagem , Nicotinamida Fosforribosiltransferase/genética
6.
Muscle Nerve ; 60(6): 801-810, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31531861

RESUMO

INTRODUCTION: Improved methods are needed to detect and quantify age-related muscle change. In this study we assessed the electrical properties of muscle impacted by acquired mitochondrial DNA mutations via the PolG mouse, which exhibits typical age-associated features, and the impact of a potential therapy, nicotinamide mononucleotide (NMN). METHODS: The gastrocnemii of 24 PolG and 30 wild-type (WT) mice (8 PolG and 17 WT treated with NMN) were studied in an electrical impedance-measuring cell. Conductivity and relative permittivity were determined from the impedance data. Myofiber cross-sectional area (CSA) was quantified histologically. RESULTS: Untreated PolG mice demonstrated alterations in several impedance features, including 50-kHz relative permittivity and center frequency. A potential effect of NMN was also observed in these parameters in PolG but not WT animals. Impedance values correlated with myofiber CSA. DISCUSSION: Electrical impedance is sensitive to myofiber features considered characteristic of aging and to the impact of a potential therapy.


Assuntos
Senilidade Prematura/fisiopatologia , Fibras Musculares Esqueléticas/patologia , Músculo Esquelético/fisiopatologia , Senilidade Prematura/patologia , Animais , Tamanho Celular , Polimerase do DNA Mitocondrial/genética , DNA Mitocondrial/genética , Modelos Animais de Doenças , Impedância Elétrica , Técnicas de Introdução de Genes , Camundongos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Mutação , Miografia/métodos , Mononucleotídeo de Nicotinamida/farmacologia
7.
Int J Mol Sci ; 20(16)2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31430957

RESUMO

Sorafenib is a multi-kinase inhibitor and one of the few systemic treatment options for patients with advanced hepatocellular carcinomas (HCCs). Resistance to sorafenib develops frequently and could be mediated by the nicotinamide adenine dinucleotide (NAD)-dependent deacetylase sirtuin (SIRT)1. We aimed to test whether sorafenib efficacy is influenced by cellular NAD levels and NAD-dependent SIRT1 function. We analyzed sorafenib effects on apoptosis induction, NAD salvage, mitochondrial function, and related signaling pathways in HCC cell lines (HepG2, Hep3B, und HUH7) overexpressing SIRT1 or supplemented with the NAD metabolite nicotinamide mononucleotide (NMN) compared to controls. Treatment of HCC cell lines with sorafenib dose-dependently induced apoptosis and a significant decrease in cellular NAD concentrations. The SIRT1 protein was downregulated in HUH7 cells but not in Hep3B cells. After sorafenib treatment, mitochondrial respiration in permeabilized cells was lower, citrate synthase activity was attenuated, and cellular adenosine triphosphate (ATP) levels were decreased. Concomitant to increased phosphorylation of adenosine monophosphate (AMP)-activated protein kinase (AMPK), sorafenib treatment led to decreased activity of the mechanistic target of rapamycin (mTOR), indicative of energy deprivation. Transient overexpression of SIRT1, as well as NAD repletion by NMN, decreased sorafenib-induced apoptosis. We can, therefore, conclude that sorafenib influences the NAD/SIRT1/AMPK axis. Overexpression of SIRT1 could be an underlying mechanism of resistance to sorafenib treatment in HCC.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Sirtuína 1/metabolismo , Sorafenibe/farmacologia , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/metabolismo , Mononucleotídeo de Nicotinamida/metabolismo
8.
Geroscience ; 41(4): 419-439, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31463647

RESUMO

Understanding molecular mechanisms involved in vascular aging is essential to develop novel interventional strategies for treatment and prevention of age-related vascular pathologies. Recent studies provide critical evidence that vascular aging is characterized by NAD+ depletion. Importantly, in aged mice, restoration of cellular NAD+ levels by treatment with the NAD+ booster nicotinamide mononucleotide (NMN) exerts significant vasoprotective effects, improving endothelium-dependent vasodilation, attenuating oxidative stress, and rescuing age-related changes in gene expression. Strong experimental evidence shows that dysregulation of microRNAs (miRNAs) has a role in vascular aging. The present study was designed to test the hypothesis that age-related NAD+ depletion is causally linked to dysregulation of vascular miRNA expression. A corollary hypothesis is that functional vascular rejuvenation in NMN-treated aged mice is also associated with restoration of a youthful vascular miRNA expression profile. To test these hypotheses, aged (24-month-old) mice were treated with NMN for 2 weeks and miRNA signatures in the aortas were compared to those in aortas obtained from untreated young and aged control mice. We found that protective effects of NMN treatment on vascular function are associated with anti-aging changes in the miRNA expression profile in the aged mouse aorta. The predicted regulatory effects of NMN-induced differentially expressed miRNAs in aged vessels include anti-atherogenic effects and epigenetic rejuvenation. Future studies will uncover the mechanistic role of miRNA gene expression regulatory networks in the anti-aging effects of NAD+ booster treatments and determine the links between miRNAs regulated by NMN and sirtuin activators and miRNAs known to act in the conserved pathways of aging and major aging-related vascular diseases.


Assuntos
Envelhecimento/metabolismo , Aorta/metabolismo , Suplementos Nutricionais , Endotélio Vascular/metabolismo , MicroRNAs/metabolismo , Mononucleotídeo de Nicotinamida/farmacologia , Envelhecimento/genética , Animais , Aterosclerose , Epigênese Genética , Perfilação da Expressão Gênica , Camundongos Endogâmicos C57BL , Rejuvenescimento
9.
Nat Commun ; 10(1): 3241, 2019 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-31324777

RESUMO

Pharmacological strategies that boost intracellular NAD+ are highly coveted for their therapeutic potential. One approach is activation of nicotinamide phosphoribosyltransferase (NAMPT) to increase production of nicotinamide mononucleotide (NMN), the predominant NAD+ precursor in mammalian cells. A high-throughput screen for NAMPT activators and hit-to-lead campaign yielded SBI-797812, a compound that is structurally similar to active-site directed NAMPT inhibitors and blocks binding of these inhibitors to NAMPT. SBI-797812 shifts the NAMPT reaction equilibrium towards NMN formation, increases NAMPT affinity for ATP, stabilizes phosphorylated NAMPT at His247, promotes consumption of the pyrophosphate by-product, and blunts feedback inhibition by NAD+. These effects of SBI-797812 turn NAMPT into a "super catalyst" that more efficiently generates NMN. Treatment of cultured cells with SBI-797812 increases intracellular NMN and NAD+. Dosing of mice with SBI-797812 elevates liver NAD+. Small molecule NAMPT activators such as SBI-797812 are a pioneering approach to raise intracellular NAD+ and realize its associated salutary effects.


Assuntos
Ativadores de Enzimas/farmacologia , NAD/metabolismo , Mononucleotídeo de Nicotinamida/metabolismo , Nicotinamida Fosforribosiltransferase/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Células A549 , Animais , Biocatálise/efeitos dos fármacos , Ativadores de Enzimas/administração & dosagem , Ativadores de Enzimas/química , Humanos , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos , Estrutura Molecular , Fosforilação/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/administração & dosagem , Bibliotecas de Moléculas Pequenas/química
10.
Reproduction ; 158(2): 169-179, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31226694

RESUMO

Male fertility and sperm quality are negatively impacted by obesity. Furthermore, recent evidence has shown that male offspring from obese rat mothers also have reduced sperm quality and fertility. Here, we extend work in this area by comparing the effects of both maternal obesity and offspring post-weaning diet-induced obesity, as well as their combination, on sperm quality in mice. We additionally tested whether administration of the NAD+-booster nicotinamide mononucleotide (NMN) can ameliorate the negative effects of obesity and maternal obesity on sperm quality. We previously showed that intraperitoneal (i.p.) injection of NMN can reduce the metabolic deficits induced by maternal obesity or post-weaning dietary obesity in mice. In this study, female mice were fed a high-fat diet (HFD) for 6 weeks until they were 18% heavier than a control diet group. Thereafter, HFD and control female mice were mated with control diet males, and male offspring were weaned into groups receiving control or HFD. At 30 weeks of age, mice received 500 mg/kg body weight NMN or vehicle PBS i.p. for 21 days. As expected, adiposity was increased by both maternal and post-weaning HFD but reduced by NMN supplementation. Post-weaning HFD reduced sperm count and motility, while maternal HFD increased offspring sperm DNA fragmentation and levels of aberrant sperm chromatin. There was no evidence that the combination of post-weaning and maternal HFD exacerbated the impacts in sperm quality suggesting that they impact spermatogenesis through different mechanisms. Surprisingly NMN reduced sperm count, vitality and increased sperm oxidative DNA damage, which was associated with increased NAD+ in testes. A subsequent experiment using oral NMN at 400 mg/kg body weight was not associated with reduced sperm viability, oxidative stress, mitochondrial dysfunction or increased NAD+ in testes, suggesting that the negative impacts on sperm could be dependent on dose or mode of administration.


Assuntos
Infertilidade Masculina/etiologia , Mononucleotídeo de Nicotinamida/farmacologia , Obesidade Materna , Efeitos Tardios da Exposição Pré-Natal , Espermatozoides/efeitos dos fármacos , Animais , Feminino , Masculino , Camundongos Endogâmicos C57BL , Gravidez
11.
Redox Biol ; 24: 101192, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31015147

RESUMO

Adjustment of cerebral blood flow (CBF) to neuronal activity via neurovascular coupling (NVC) has an essential role in maintenance of healthy cognitive function. In aging increased oxidative stress and cerebromicrovascular endothelial dysfunction impair NVC, contributing to cognitive decline. There is increasing evidence showing that a decrease in NAD+ availability with age plays a critical role in a range of age-related cellular impairments but its role in impaired NVC responses remains unexplored. The present study was designed to test the hypothesis that restoring NAD+ concentration may exert beneficial effects on NVC responses in aging. To test this hypothesis 24-month-old C57BL/6 mice were treated with nicotinamide mononucleotide (NMN), a key NAD+ intermediate, for 2 weeks. NVC was assessed by measuring CBF responses (laser Doppler flowmetry) evoked by contralateral whisker stimulation. We found that NVC responses were significantly impaired in aged mice. NMN supplementation rescued NVC responses by increasing endothelial NO-mediated vasodilation, which was associated with significantly improved spatial working memory and gait coordination. These findings are paralleled by the sirtuin-dependent protective effects of NMN on mitochondrial production of reactive oxygen species and mitochondrial bioenergetics in cultured cerebromicrovascular endothelial cells derived from aged animals. Thus, a decrease in NAD+ availability contributes to age-related cerebromicrovascular dysfunction, exacerbating cognitive decline. The cerebromicrovascular protective effects of NMN highlight the preventive and therapeutic potential of NAD+ intermediates as effective interventions in patients at risk for vascular cognitive impairment (VCI).


Assuntos
Circulação Cerebrovascular , Disfunção Cognitiva , Suplementos Nutricionais , Endotélio Vascular/metabolismo , Acoplamento Neurovascular , Mononucleotídeo de Nicotinamida/administração & dosagem , Fatores Etários , Animais , Comportamento Animal , Biomarcadores , Disfunção Cognitiva/tratamento farmacológico , Humanos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Mitocôndrias/metabolismo , Óxido Nítrico/metabolismo , Estresse Oxidativo/efeitos dos fármacos , RNA Interferente Pequeno/genética , Espécies Reativas de Oxigênio/metabolismo
12.
Biogerontology ; 20(4): 381-395, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30838484

RESUMO

Nicotinamide adenine dinucleotide (NAD+) has been described as central coenzyme of redox reactions and is a key regulator of stress resistance and longevity. Aging is a multifactorial and irreversible process that is characterized by a gradual diminution in physiological functions in an organism over time, leading to development of age-associated pathologies and eventually increasing the probability of death. Ischemia is the lack of nutritive blood flow that causes damage and mortality that mostly occurs in various organs during aging. During the process of aging and related ischemic conditions, NAD+ levels decline and lead to nuclear and mitochondrial dysfunctions, resulting in age-related pathologies. The majority of studies have shown that restoring of NAD+ using supplementation with intermediates such as nicotinamide mononucleotide and nicotinamide riboside can be a valuable strategy for recovery of ischemic injury and age-associated defects. This review summarizes the molecular mechanisms responsible for the reduction in NAD+ levels during ischemic disorders and aging, as well as a particular focus is given to the recent progress in the understanding of NAD+ precursor's effects on aging and ischemia.


Assuntos
Envelhecimento/fisiologia , Isquemia , NAD/metabolismo , Descoberta de Drogas , Humanos , Isquemia/metabolismo , Isquemia/fisiopatologia , Isquemia/terapia , Mitocôndrias/metabolismo , Niacinamida/análogos & derivados , Niacinamida/farmacologia , Mononucleotídeo de Nicotinamida/farmacologia
13.
Clin Exp Nephrol ; 23(8): 987-994, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30859351

RESUMO

Tubules interact with glomeruli, which are composed of podocytes, parietal epithelial cells, mesangial cells, and glomerular endothelial cells. Glomerular-tubular balance and tubuloglomerular feedback are the two components of the tubular-glomerular interplay, which has been demonstrated to play roles in physiological renal function and in diabetic kidney disease (DKD), in which proteins leaking from glomeruli arrive at tubular regions, leading to further tubular injury caused by the accumulation of proteinuria-inducing reactive oxygens species and various cytokines. In the current review, we present our recent work identifying a novel tubular-glomerular interplay in DKD mediated by sirtuin 1 and nicotinamide mononucleotide.


Assuntos
Nefropatias Diabéticas/enzimologia , Glomérulos Renais/enzimologia , Túbulos Renais/enzimologia , NAD/metabolismo , Mononucleotídeo de Nicotinamida/metabolismo , Sirtuína 1/metabolismo , Animais , Distinções e Prêmios , Claudina-1/genética , Claudina-1/metabolismo , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/patologia , Epigênese Genética , Regulação da Expressão Gênica , Transportador de Glucose Tipo 2/genética , Transportador de Glucose Tipo 2/metabolismo , Humanos , Glomérulos Renais/patologia , Túbulos Renais/patologia , Transdução de Sinais , Sirtuína 1/genética , Transportador 2 de Glucose-Sódio/genética , Transportador 2 de Glucose-Sódio/metabolismo
14.
Biomolecules ; 9(1)2019 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-30669679

RESUMO

Nicotinamide mononucleotide (NMN) is a nucleotide that is most recognized for its role as an intermediate of nicotinamide adenine dinucleotide (NAD+) biosynthesis. Although the biosynthetic pathway of NMN varies between eukaryote and prokaryote, two pathways are mainly followed in case of eukaryotic human-one is through the salvage pathway using nicotinamide while the other follows phosphorylation of nicotinamide riboside. Due to the unavailability of a suitable transporter, NMN enters inside the mammalian cell in the form of nicotinamide riboside followed by its subsequent conversion to NMN and NAD+. This particular molecule has demonstrated several beneficial pharmacological activities in preclinical studies, which suggest its potential therapeutic use. Mostly mediated by its involvement in NAD+ biosynthesis, the pharmacological activities of NMN include its role in cellular biochemical functions, cardioprotection, diabetes, Alzheimer's disease, and complications associated with obesity. The recent groundbreaking discovery of anti-ageing activities of this chemical moiety has added a valuable essence in the research involving this molecule. This review focuses on the biosynthesis of NMN in mammalian and prokaryotic cells and mechanism of absorption along with the reported pharmacological activities in murine model.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Doenças Cardiovasculares/tratamento farmacológico , Diabetes Mellitus/tratamento farmacológico , Mononucleotídeo de Nicotinamida/uso terapêutico , Animais , Humanos , NAD/biossíntese , Mononucleotídeo de Nicotinamida/metabolismo , Obesidade/complicações
15.
Neurochem Res ; 44(10): 2280-2287, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30661231

RESUMO

Dysfunctions in NAD+ metabolism are associated with neurodegenerative diseases, acute brain injury, diabetes, and aging. Loss of NAD+ levels results in impairment of mitochondria function, which leads to failure of essential metabolic processes. Strategies to replenish depleted NAD+ pools can offer significant improvements of pathologic states. NAD+ levels are maintained by two opposing enzymatic reactions, one is the consumption of NAD+ while the other is the re-synthesis of NAD+. Inhibition of NAD+ degrading enzymes, poly-ADP-ribose polymerase 1 (PARP1) and ectoenzyme CD38, following brain ischemic insult can provide neuroprotection. Preservation of NAD+ pools by administration of NAD+ precursors, such as nicotinamide (Nam) or nicotinamide mononucleotide (NMN), also offers neuroprotection. However, NMN treatment demonstrates to be a promising candidate as a therapeutic approach due to its multi-targeted effect acting as PARP1 and CD38 inhibitor, sirtuins activator, mitochondrial fission inhibitor, and NAD+ supplement. Many neurodegenerative diseases or acute brain injury activate several cellular death pathways requiring a treatment strategy that will target these mechanisms. Since NMN demonstrated the ability to exert its effect on several cellular metabolic pathways involved in brain pathophysiology it seems to be one of the most promising candidates to be used for successful neuroprotection.


Assuntos
Encéfalo/efeitos dos fármacos , Hidrolases/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mononucleotídeo de Nicotinamida/farmacologia , Animais , Encéfalo/metabolismo , Humanos , Hidrolases/metabolismo , Mitocôndrias/metabolismo , NAD/efeitos dos fármacos , NAD/metabolismo , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/metabolismo , Niacinamida/metabolismo , Niacinamida/farmacologia , Mononucleotídeo de Nicotinamida/metabolismo
16.
Toxicol Appl Pharmacol ; 362: 20-27, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30292833

RESUMO

Aluminum (Al) recognized as a persistent environmental contaminant is associated with bone diseases. Nicotinamide mononucleotide (NMN) is an intermediate of nicotinamide adenine dinucleotide (NAD+) biosynthesis widely used to replenish NAD+. Increasing evidences demonstrated that replenishment of NAD+ can protect against bone loss. However, the potentially protective effects of NMN against Al-induced bone impairment and the underlying mechanisms remain unknown. In the present study, we sought to investigate the protective effects of NMN on Al-induced bone damages and elucidate the potential mechanisms. We orally exposed AlCl3 (10 mg/L) to Sprague-Dawley rats in drinking water for 12 weeks while NMN (20 mg/kg) were intraperitoneally injected in last 4 weeks. We found that Al could induce bone damages, bone loss and oxidative stress. In addition, we showed that Al triggered inflammatory responses, which is mediated by the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome activation. However, NMN treatment significantly alleviated Al-induced bone injuries by decreasing bone loss, suppressing oxidative stress as well as inhibiting Thioredoxin-interacting protein (TXNIP)-NLRP3 inflammasome pathway and pro-inflammatory cytokine production in vivo and in vitro. Meanwhile, treatment with TXNIP siRNA performed the same protective effects as NMN in Al-treated MC3T3-E1 cells. Collectively, our results suggest that NMN may reduce Al-induced bone loss partly by suppression of the TXNIP-NLRP3 inflammasome pathway.


Assuntos
Cloreto de Alumínio/toxicidade , Reabsorção Óssea/tratamento farmacológico , Proteínas de Transporte/antagonistas & inibidores , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Mononucleotídeo de Nicotinamida/uso terapêutico , Animais , Reabsorção Óssea/induzido quimicamente , Reabsorção Óssea/diagnóstico por imagem , Reabsorção Óssea/metabolismo , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular , Linhagem Celular , Fêmur/diagnóstico por imagem , Fêmur/efeitos dos fármacos , Fêmur/metabolismo , Masculino , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Mononucleotídeo de Nicotinamida/farmacologia , Ratos Sprague-Dawley , Microtomografia por Raio-X
17.
Proc Natl Acad Sci U S A ; 115(42): 10654-10659, 2018 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-30257945

RESUMO

Axon degeneration, a hallmark of chemotherapy-induced peripheral neuropathy (CIPN), is thought to be caused by a loss of the essential metabolite nicotinamide adenine dinucleotide (NAD+) via the prodegenerative protein SARM1. Some studies challenge this notion, however, and suggest that an aberrant increase in a direct precursor of NAD+, nicotinamide mononucleotide (NMN), rather than loss of NAD+, is responsible. In support of this idea, blocking NMN accumulation in neurons by expressing a bacterial NMN deamidase protected axons from degeneration. We hypothesized that protection could similarly be achieved by reducing NMN production pharmacologically. To achieve this, we took advantage of an alternative pathway for NAD+ generation that goes through the intermediate nicotinic acid mononucleotide (NAMN), rather than NMN. We discovered that nicotinic acid riboside (NAR), a precursor of NAMN, administered in combination with FK866, an inhibitor of the enzyme nicotinamide phosphoribosyltransferase that produces NMN, protected dorsal root ganglion (DRG) axons against vincristine-induced degeneration as well as NMN deamidase. Introducing a different bacterial enzyme that converts NAMN to NMN reversed this protection. Collectively, our data indicate that maintaining NAD+ is not sufficient to protect DRG neurons from vincristine-induced axon degeneration, and elevating NMN, by itself, is not sufficient to cause degeneration. Nonetheless, the combination of FK866 and NAR, which bypasses NMN formation, may provide a therapeutic strategy for neuroprotection.


Assuntos
Acrilamidas/farmacologia , NAD/metabolismo , Degeneração Neural/prevenção & controle , Neurônios/efeitos dos fármacos , Niacinamida/análogos & derivados , Mononucleotídeo de Nicotinamida/análogos & derivados , Piperidinas/farmacologia , Vincristina/toxicidade , Animais , Antineoplásicos Fitogênicos/toxicidade , Combinação de Medicamentos , Francisella tularensis/enzimologia , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Gânglios Espinais/patologia , Degeneração Neural/induzido quimicamente , Degeneração Neural/metabolismo , Neurônios/metabolismo , Neurônios/patologia , Niacinamida/farmacologia , Mononucleotídeo de Nicotinamida/metabolismo , Nicotinamida Fosforribosiltransferase/antagonistas & inibidores , Nicotinamida Fosforribosiltransferase/metabolismo
18.
JCI Insight ; 3(17)2018 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-30185676

RESUMO

Hemorrhagic shock depletes nicotinamide adenine dinucleotide (NAD) and causes metabolic derangements that, in severe cases, cannot be overcome, even after restoration of blood volume and pressure. However, current strategies to treat acute blood loss do not target cellular metabolism. We hypothesized that supplemental nicotinamide mononucleotide (NMN), the immediate biosynthetic precursor to NAD, would support cellular energetics and enhance physiologic resilience to hemorrhagic shock. In a rodent model of decompensated hemorrhagic shock, rats receiving NMN displayed significantly reduced lactic acidosis and serum IL-6 levels, two strong predictors of mortality in human patients. In both livers and kidneys, NMN increased NAD levels and prevented mitochondrial dysfunction. Moreover, NMN preserved mitochondrial function in isolated hepatocytes cocultured with proinflammatory cytokines, indicating a cell-autonomous protective effect that is independent from the reduction in circulating IL-6. In kidneys, but not in livers, NMN was sufficient to prevent ATP loss following shock and resuscitation. Overall, NMN increased the time animals could sustain severe shock before requiring resuscitation by nearly 25% and significantly improved survival after resuscitation (P = 0.018), whether NMN was given as a pretreatment or only as an adjunct during resuscitation. Thus, we demonstrate that NMN substantially mitigates inflammation, improves cellular metabolism, and promotes survival following hemorrhagic shock.


Assuntos
Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , NAD/metabolismo , Mononucleotídeo de Nicotinamida/farmacologia , Choque Hemorrágico/prevenção & controle , Acidose Láctica/sangue , Trifosfato de Adenosina , Animais , Citocinas/metabolismo , Hepatócitos/metabolismo , Humanos , Inflamação , Interleucina-6/sangue , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Masculino , Doenças Mitocondriais/prevenção & controle , Nicotinamida Fosforribosiltransferase/metabolismo , Nicotinamida-Nucleotídeo Adenililtransferase/metabolismo , Ratos , Ressuscitação , Choque Hemorrágico/mortalidade , Análise de Sobrevida
19.
Sci Rep ; 8(1): 12278, 2018 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-30115969

RESUMO

Diabetes is a chronic and progressive disease with continuously increasing prevalence, rising financial pressure on the worldwide healthcare systems. Recently, the insulin resistance, hallmark of type 2 diabetes, was cured in mice treated with NAD+ precursor ß-nicotinamide mononucleotide (NMN), no toxic effects being reported. However, NMN has a high price tag, more cost effective production methods are needed. This study proposes a biotechnological NMN production method in Escherichia coli. We show that bicistronic expression of recombinant nicotinamide phosphoribosyl transferase (Nampt) and phosphoribosyl pyrophosphate (PRPP) synthetase in the presence of nicotinamide (NAM) and lactose may be a successful strategy for cost effective NMN production. Protein expression vectors carrying NAMPT gene from Haemophilus ducreyi and PRPP synthetase from Bacillus amyloliquefaciens with L135I mutation were transformed in Escherichia coli BL21(DE3)pLysS. NMN production reached a maximum of 15.42 mg per L of bacterial culture (or 17.26 mg per gram of protein) in these cells grown in PYA8 medium supplemented with 0.1% NAM and 1% lactose.


Assuntos
Escherichia coli/metabolismo , Mononucleotídeo de Nicotinamida/biossíntese , Sequência de Aminoácidos , Reatores Biológicos , Meios de Cultura , Cinética , Nicotinamida Fosforribosiltransferase/química , Nicotinamida Fosforribosiltransferase/genética , Nicotinamida Fosforribosiltransferase/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos
20.
J Mol Cell Cardiol ; 121: 155-162, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29958828

RESUMO

Stimulation of the cytosolic NAD+ dependent deacetylase SIRT1 is cardioprotective against ischemia-reperfusion (IR) injury. NAD+ precursors including nicotinamide mononucleotide (NMN) are thought to induce cardioprotection via SIRT1. Herein, while NMN protected perfused hearts against IR (functional recovery: NMN 42 ±â€¯7% vs. vehicle 11 ±â€¯3%), this protection was insensitive to the SIRT1 inhibitor splitomicin (recovery 47 ±â€¯8%). Although NMN-induced cardioprotection was absent in Sirt3-/- hearts (recovery 9 ±â€¯5%), this was likely due to enhanced baseline injury in Sirt3-/- (recovery 6 ±â€¯2%), since similar injury levels in WT hearts also blunted the protective efficacy of NMN. Considering alternative cardiac effects of NMN, and the requirement of glycolysis for NAD+, we hypothesized NMN may confer protection in part via direct stimulation of cardiac glycolysis. In primary cardiomyocytes, NMN induced cytosolic and extracellular acidification and elevated lactate. In addition, [U-13C]glucose tracing in intact hearts revealed that NMN stimulated glycolytic flux. Consistent with a role for glycolysis in NMN-induced protection, hearts perfused without glucose (palmitate as fuel source), or hearts perfused with galactose (no ATP from glycolysis) exhibited no benefit from NMN (recovery 11 ±â€¯4% and 15 ±â€¯2% respectively). Acidosis during early reperfusion is known to be cardioprotective (i.e., acid post-conditioning), and we also found that NMN was cardioprotective when delivered acutely at reperfusion (recovery 39 ±â€¯8%). This effect of NMN was not additive with acidosis, suggesting overlapping mechanisms. We conclude that the acute cardioprotective benefits of NMN are mediated in part via glycolytic stimulation, with the downstream protective mechanism involving enhanced ATP synthesis during ischemia and/or enhanced acidosis during reperfusion.


Assuntos
Miocárdio/metabolismo , Mononucleotídeo de Nicotinamida/metabolismo , Traumatismo por Reperfusão/tratamento farmacológico , Sirtuína 1/genética , Sirtuína 3/genética , Acidose/genética , Acidose/metabolismo , Acidose/patologia , Ácidos/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Cardiotônicos/farmacologia , Glucose/metabolismo , Glicólise/genética , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Miocárdio/patologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , NAD/metabolismo , Naftalenos/farmacologia , Mononucleotídeo de Nicotinamida/farmacologia , Pironas/farmacologia , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia
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