P6274Role of the nicotinamide riboside kinase 2 in NAD metabolism in the heart in basal and pathological condition

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
R Deloux ◽  
C Tannous ◽  
A Karoui ◽  
N Mougenot ◽  
Z Li ◽  
...  

Abstract Background NAD is a major coenzyme in energy metabolism and a substrate for SIRT1 and PARP1 enzymes involved in the response to energy and oxidative stress. We have shown the beneficial effects of nicotinamide riboside (NR), a new type of vitamin B3, on cardiac function and remodelling in a mouse model of dilated cardiomyopathy (DCM) triggered by deletion of the SRF transcription factor in the heart (Srf-HKO) (1). This functional improvement correlated with protection of NAD metabolism and a robust increase in cardiac expression of the Nicotinamide Riboside Kinase 2 (NMRK2) that phosphorylates NR to generate nicotinamide mononucleotide (NMN), an immediate precursor of NAD. Purpose We aim to understand the role of the NMRK2-mediated NAD biosynthetic pathway in the heart at baseline and in the DCM context. Methods We generated Nmrk2-KO mice that we bred with Srf-HKO to generate double KO mice (db-KO). We analysed cardiac function and remodelling by echocardiography and quantified myocardial NAD levels at baseline and following NR supplementation in food. Results Nmrk2KO mice developed a progressive eccentric remodelling of LV and decline in EF with aging. At 24-mo, we observed a reduction of myocardial NAD levels (−40% compared to wild type, p<0.05) and of LVEF (61%, SD 6.3% in Nmrk2-KO vs 78%, SD 1.5% in WT, p<0.05). To assess the contribution of cardiac Nmrk2 induction to NR response in DCM, we compared SrfH-KO and db-KO mice fed with control diet (CD) or NR supplemented diet for 40 days starting at young age (2-mo). NR reduced the extent of LV eccentric remodelling and drop in EF as well as the thinning of the LV posterior wall in both genotypes (2-way ANOVA, diet effect, p<0.01). Myocardial NAD levels were more reduced in db-KO mice under CD diet (−22% compared to control mice, p<0.05) than in Srf-HKO mice (−11%, non-significant), when we previously showed a 25% drop in myocardial NAD in aged SrfHKO mice (1). NR partially preserved cardiac NAD pool in db-KOmice (−10% compared to controls, non-significant). Parallel pathways for NMN synthesis were studied. Nampt gene expression was significantly repressed in db-KO mice fed with CD or NR diet compared to control mice (−50% in average, p<0.01), when there was only a trend toward lower expression in SrfHKO mice (−40% in average, p>0.05). Nmrk1 gene expression trended to increase in all groups compared to wild-type control mice. Conclusion We show that NMRK2 pathway plays a role in the maintenance of basal cardiac function and NAD levels when relying on the endogenous myocardial NR pool. In contrast, the beneficial effect of a therapeutic dose of NR is not affected by the lack of NMRK2 suggesting compensation by NMRK1 in the heart and/or that NR beneficial effects on cardiac function could be mediated through its action on systemic metabolism. Aging appears as an aggravating factor for the loss of myocardial NAD coenzyme in DCM. Acknowledgement/Funding Agence Nationale pour la Recherche, Fondation de France

2007 ◽  
Vol 97 (2) ◽  
pp. 389-398 ◽  
Author(s):  
Patricia Pérez-Matute ◽  
Nerea Pérez-Echarri ◽  
J. Alfredo Martínez ◽  
Amelia Marti ◽  
María J. Moreno-Aliaga

n-3 PUFA have shown potential anti-obesity and insulin-sensitising properties. However, the mechanisms involved are not clearly established. The aim of the present study was to assess the effects of EPA administration, one of the n-3 PUFA, on body-weight gain and adiposity in rats fed on a standard or a high-fat (cafeteria) diet. The actions on white adipose tissue lipolysis, apoptosis and on several genes related to obesity and insulin resistance were also studied. Control and cafeteria-induced overweight male Wistar rats were assigned into two subgroups, one of them daily received EPA ethyl ester (1 g/kg) for 5 weeks by oral administration. The high-fat diet induced a very significant increase in both body weight and fat mass. Rats fed with the cafeteria diet and orally treated with EPA showed a marginally lower body-weight gain (P = 0·09), a decrease in food intake (P < 0·01) and an increase in leptin production (P < 0·05). EPA administration reduced retroperitoneal adipose tissue weight (P < 0·05) which could be secondary to the inhibition of the adipogenic transcription factor PPARγ gene expression (P < 0·001), and also to the increase in apoptosis (P < 0·05) found in rats fed with a control diet. TNFα gene expression was significantly increased (P < 0·05) by the cafeteria diet, while EPA treatment was able to prevent (P < 0·01) the rise in this inflammatory cytokine. Adiposity-corrected adiponectin plasma levels were increased by EPA. These actions on both TNFα and adiponectin could explain the beneficial effects of EPA on insulin resistance induced by the cafeteria diet.


2000 ◽  
Vol 279 (6) ◽  
pp. H2846-H2854 ◽  
Author(s):  
Thomas G. Hampton ◽  
Ju-Feng Wang ◽  
Joseph DeAngelis ◽  
Ivo Amende ◽  
Kenneth D. Philipson ◽  
...  

Enhanced gene expression of the Na+/Ca2+exchanger in failing hearts may be a compensatory mechanism to promote influx and efflux of Ca2+, despite impairment of the sarcoplasmic reticulum (SR). To explore this, we monitored intracellular calcium (Cai 2+) and cardiac function in mouse hearts engineered to overexpress the Na+/Ca2+ exchanger and subjected to ischemia and hypoxia, conditions known to impair SR Cai 2+transport and contractility. Although baseline Cai 2+and function were similar between transgenic and wild-type hearts, significant differences were observed during ischemia and hypoxia. During early ischemia, Cai 2+ was preserved in transgenic hearts but significantly altered in wild-type hearts. Transgenic hearts maintained 40% of pressure-generating capacity during early ischemia, whereas wild-type hearts maintained only 25% ( P < 0.01). During hypoxia, neither peak nor diastolic Cai 2+ decreased in transgenic hearts. In contrast, both peak and diastolic Cai 2+ decreased significantly in wild-type hearts. The decline of Cai 2+ was abbreviated in hypoxic transgenic hearts but prolonged in wild-type hearts. Peak systolic pressure decreased by nearly 10% in hypoxic transgenic hearts and >25% in wild-type hearts ( P < 0.001). These data demonstrate that enhanced gene expression of the Na+/Ca2+ exchanger preserves Cai 2+ homeostasis during ischemia and hypoxia, thereby preserving cardiac function in the acutely failing heart.


2019 ◽  
Author(s):  
Agnes Wilhelmina Boots ◽  
Carmen Veith ◽  
Catrin Albrecht ◽  
Roger Bartholome ◽  
Marie Jose Drittij ◽  
...  

Abstract Background Idiopathic pulmonary fibrosis (IPF) is a chronic, lethal disease of unknown etiology. Current treatment comprises two FDA-approved drugs that can slow down yet not stop or reverse the disease. As IPF pathology is associated with an altered redox balance, adding a redox modulating component to current therapy might exert beneficial effects. Quercetin is a dietary antioxidant with strong redox modulating capacities suggested to exert part of its antioxidative effects via activation of the redox-sensitive transcription factor Nrf2. Therefore, the aim of the present study was to investigate if quercetin can exert anti-fibrotic effects in a mouse model of bleomycin-induced pulmonary fibrogenesis through Nrf2-dependent restoration of redox imbalance. Methods Homozygous Nrf2 deficient mice and their wildtype littermates were fed a control diet without or with 800 mg/kg quercetin from 7 days prior to a single 1 µg/2µl per g BW bleomycin challenge until they were sacrificed 14 days afterwards. Lung tissue and plasma were collected to determine markers of fibrosis (expression of extracellular matrix genes and histopathology), inflammation (pulmonary gene expression and plasma levels of Tumor Necrosis Factor-α (TNFα) and Keratinocyte Chemoattrachtant (KC)), and redox balance (pulmonary gene expression of antioxidants and malondialdehyde-dG (MDA)- DNA adducts). Results Mice fed the enriched diet had significantly enhanced plasma and pulmonary quercetin levels (11.08 ± 0.73 µM versus 7.05 ± 0.2 µM) combined with increased pulmonary expression of Nrf2 and Nrf2-responsive genes compared to mice fed the control diet. Upon bleomycin treatment, quercetin-fed mice displayed reduced expression of collagen (COL1A2) and fibronectin (FN1) and a tendency of reduced inflammatory lesions (2.8 ± 0.7 versus 1.9 ± 0.8). These beneficial effects were accompanied by reduced pulmonary gene expression of TNFα and KC, but not their plasma levels, and enhanced Nrf2-induced pulmonary antioxidant defences. In Nrf2 deficient mice, no effect of the dietary antioxidant on either histology or inflammatory lesions was observed. Conclusion Quercetin exerts anti-fibrogenic and anti-inflammatory effects on bleomycin-induced pulmonary damage in mice possibly through modulation of the redox balance by inducing Nrf2. However, quercetin could not rescue the bleomycin-induced pulmonary damage indicating that quercetin alone cannot ameliorate the progression of IPF.


2020 ◽  
Vol 8 (1) ◽  
pp. 67 ◽  
Author(s):  
Seonghun Won ◽  
Ali Hamidoghli ◽  
Wonsuk Choi ◽  
Youngjin Park ◽  
Won Je Jang ◽  
...  

An eight-week feeding trial was conducted to evaluate the effects of a basal control diet (CON), Bacillus subtilis at 107 (BS7) and at 108 CFU/g diet (BS8), Lactococcus lactis at 107 CFU/g (LL7) and at 108 CFU/g diet (LL8), and oxytetracycline (OTC) at 4 g/kg diet on Nile tilapia. Fish with initial body weight of 2.83 ± 0.05 g (mean ± SD) were fed two times a day. Weight gain, specific growth rate, feed efficiency, protein efficiency ratio and lysozyme activity of fish fed BS8, LL8 and LL7 diets were significantly higher than those of fish fed CON diet (p < 0.05). Superoxide dismutase and myeloperoxidase activity of fish fed BS8, LL8, BS7, LL7 and OTC diets were significantly higher than those of fish fed CON diet. Intestinal villi length and muscular layer thickness of fish fed BS8, LL8 and LL7 diets were significantly higher than those of fish fed CON and OTC diets. Also, heat shock protein 70 (HSP70), interleukin (IL-1β), interferon-gamma (IFN-γ) and tumour necrosis factor (TNF-α) gene expression of fish fed BS8 and LL8 diets were significantly higher than those of fish fed CON diet. After 13 days of challenge test, cumulative survival rate of fish fed BS8 and LL8 diets were significantly higher than those of fish fed CON, BS7 and OTC diets. Based on these results, B. subtilis and L. lactis at 108 (CFU/g) could replace antibiotics, and have beneficial effects on growth, immunity, histology, gene expression, and disease resistance in Nile tilapia.


2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Erica M. Weekman ◽  
Tiffany L. Sudduth ◽  
Brittani R. Price ◽  
Abigail E. Woolums ◽  
Danielle Hawthorne ◽  
...  

Abstract Background Vascular contributions to cognitive impairment and dementia (VCID) are the second leading cause of dementia behind only Alzheimer’s disease (AD); however, VCID is commonly found as a co-morbidity with sporadic AD. We have previously established a mouse model of VCID by inducing hyperhomocysteinemia in both wild-type and amyloid depositing mice. While we have shown the time course of neuropathological events in the wild-type mice with hyperhomocysteinemia, the effect of amyloid deposition on this time course remains unknown; therefore, in this study, we determined the time course of neuropathological changes in our mouse model of hyperhomocysteinemia-induced VCID in amyloid depositing mice. Methods APP/PS1 mice were placed on either a diet deficient in folate and vitamins B6 and B12 and enriched in methionine to induce hyperhomocysteinemia or a control diet for 2, 6, 10, 14, or 18 weeks. Immunohistochemistry and gene expression analysis were used to determine neuroinflammatory changes. Microhemorrhages and amyloid deposition were analyzed using histology and, finally, behavior was assessed using the 2-day radial arm water maze. Results Neuroinflammation, specifically a pro-inflammatory phenotype, was the first pathological change to occur. Specifically, we see a significant increase in gene expression of tumor necrosis factor alpha, interleukin 1 beta, interleukin 6, and interleukin 12a by 6 weeks. This was followed by cognitive deficits starting at 10 weeks. Finally, there is a significant increase in the number of microhemorrhages at 14 weeks on diet as well as redistribution of amyloid from the parenchyma to the vasculature. Conclusions The time course of these pathologies points to neuroinflammation as the initial, key player in homocysteine-induced VCID co-morbid with amyloid deposition and provides a possible therapeutic target and time points.


Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
David Sacerdoti ◽  
Sumit R Monu ◽  
Paola Pesce ◽  
Stephen J Peterson ◽  
Komal Sodhi ◽  
...  

Rational: Angiogenesis is essential in order to increase blood circulation in infarcted tissue of MI (Myocardial infarction). Increased Heme-Oxygenase (HO)-1 gene expression increases angiogenic proteins, e.g. VEGF, bFGF, EGF, angiopoietin and adiponectin. Objective: To investigate whether increased levels of HO-1, after the occurrence of a MI, improves angiogenesis and capillary formation in ischemic myocardium, thereby improving cardiac function. METHODS: Experimental MI was induced by LAD (Left anterior descending artery) ligation. C57BL6 mice were divided into 4 groups: Sham; MI; 5 days after MI treated with the HO-1 inducer, cobalt protoporphyrinIX (CoPP); and, CoPP in the presence of the HO activity inhibitor, Stannous Mesoporphyrin (SnMP). HO-1 downstream signaling proteins were determined including VEGF, CD31 and adiponectin. Echocardiography was performed weekly for 4 weeks after surgery. Results: 5 days after MI, CoPP treatment significantly increased VEGF (p<0.05 vs.MI), CD31 (p<0.05 vs.MI), and adiponectin levels (p<0.05 vs.MI). These findings were associated with a significant increase in capillary formation and blood flow in CoPP-treated animals (p<0.05 vs.MI). Echocardiography showed that left ventricle dilatation, measured as end diastolic area (EDA), was significantly reduced in CoPP- treated animals compared to MI groups (EDA: MI: 0.216±0.02cm2; MI+CoPP: 0.172±0.03 cm2; (-13%) p<0.01). This was associated with a significant decrease in apoptosis and fibrosis (P<0.05). These beneficial effects were reversed by SnMP administration. Conclusion: HO-1 improved cardiac function and enhanced angiogenesis via the recruitment of pro-angiogenic factors.


2020 ◽  
Author(s):  
Agnes Wilhelmina Boots ◽  
Carmen Veith ◽  
Catrin Albrecht ◽  
Roger Bartholome ◽  
Marie Jose Drittij ◽  
...  

Abstract Background Idiopathic pulmonary fibrosis (IPF) is a chronic, lethal disease of unknown etiology. Current treatment comprises two FDA-approved drugs that can slow down yet not stop or reverse the disease. As IPF pathology is associated with an altered redox balance, adding a redox modulating component to current therapy might exert beneficial effects. Quercetin is a dietary antioxidant with strong redox modulating capacities suggested to exert part of its antioxidative effects via activation of the redox-sensitive transcription factor Nrf2. Therefore, the aim of the present study was to investigate if quercetin can exert anti-fibrotic effects in a mouse model of bleomycin-induced pulmonary fibrogenesis through Nrf2-dependent restoration of redox imbalance. Methods Homozygous Nrf2 deficient mice and their wildtype littermates were fed a control diet without or with 800 mg/kg quercetin from 7 days prior to a single 1 µg/2µl per g BW bleomycin challenge until they were sacrificed 14 days afterwards. Lung tissue and plasma were collected to determine markers of fibrosis (expression of extracellular matrix genes and histopathology), inflammation (pulmonary gene expression and plasma levels of Tumor Necrosis Factor-α (TNFα) and Keratinocyte Chemoattrachtant (KC)), and redox balance (pulmonary gene expression of antioxidants and malondialdehyde-dG (MDA)- DNA adducts). Results Mice fed the enriched diet had significantly enhanced plasma and pulmonary quercetin levels (11.08 ± 0.73 µM versus 7.05 ± 0.2 µM) combined with increased pulmonary expression of Nrf2 and Nrf2-responsive genes compared to mice fed the control diet. Upon bleomycin treatment, quercetin-fed mice displayed reduced expression of collagen (COL1A2) and fibronectin (FN1) and a tendency of reduced inflammatory lesions (2.8 ± 0.7 versus 1.9 ± 0.8). These beneficial effects were accompanied by reduced pulmonary gene expression of TNFα and KC, but not their plasma levels, and enhanced Nrf2-induced pulmonary antioxidant defences. In Nrf2 deficient mice, no effect of the dietary antioxidant on either histology or inflammatory lesions was observed. Conclusion Quercetin exerts anti-fibrogenic and anti-inflammatory effects on bleomycin-induced pulmonary damage in mice possibly through modulation of the redox balance by inducing Nrf2. However, quercetin could not rescue the bleomycin-induced pulmonary damage indicating that quercetin alone cannot ameliorate the progression of IPF.


2018 ◽  
Vol 61 (3) ◽  
pp. R107-R121 ◽  
Author(s):  
Rachel S Fletcher ◽  
Gareth G Lavery

The concept of replenishing or elevating NAD+availability to combat metabolic disease and ageing is an area of intense research. This has led to a need to define the endogenous regulatory pathways and mechanisms cells and tissues utilise to maximise NAD+availability such that strategies to intervene in the clinical setting are able to be fully realised. This review discusses the importance of different salvage pathways involved in metabolising the vitamin B3 class of NAD+precursor molecules, with a particular focus on the recently identified nicotinamide riboside kinase pathway at both a tissue-specific and systemic level.


2020 ◽  
Author(s):  
Agnes Wilhelmina Boots ◽  
Carmen Veith ◽  
Catrin Albrecht ◽  
Roger Bartholome ◽  
Marie Jose Drittij ◽  
...  

Abstract Background Idiopathic pulmonary fibrosis (IPF) is a chronic, lethal disease of which the etiology is still not fully understood. Current treatment comprises two FDA-approved drugs that can slow down yet not stop or reverse the disease. As IPF pathology is associated with an altered redox balance, adding a redox modulating component to current therapy might exert beneficial effects. Quercetin is a dietary antioxidant with strong redox modulating capacities that is suggested to exert part of its antioxidative effects via activation of the redox-sensitive transcription factor Nrf2 that regulates endogenous antioxidant levels. Therefore, the aim of the present study was to investigate if the dietary antioxidant quercetin can exert anti-fibrotic effects in a mouse model of bleomycin-induced pulmonary fibrogenesis through Nrf2-dependent restoration of redox imbalance. Methods Homozygous Nrf2 deficient mice and their wildtype littermates were fed a control diet without or with 800 mg quercetin per kg diet from 7 days prior to a single 1 µg/2µl per g BW bleomycin challenge until they were sacrificed 14 days afterwards. Lung tissue and plasma were collected to determine markers of fibrosis (expression of extracellular matrix genes and histopathology), inflammation (pulmonary gene expression and plasma levels of Tumor Necrosis Factor-α (TNFα) and Keratinocyte Chemoattrachtant (KC)), and redox balance (pulmonary gene expression of antioxidants and malondialdehyde-dG (MDA)- DNA adducts). Results Mice fed the enriched diet for 7 days prior to the bleomycin challenge had significantly enhanced plasma and pulmonary quercetin levels (11.08 ± 0.73 µM versus 7.05 ± 0.2 µM) combined with increased expression of Nrf2 and Nrf2-responsive genes compared to mice fed the control diet in lung tissue. Upon bleomycin treatment, quercetin-fed mice displayed reduced expression of collagen (COL1A2) and fibronectin (FN1) and a tendency of reduced inflammatory lesions (2.8 ± 0.7 versus 1.9 ± 0.8). These beneficial effects were accompanied by reduced pulmonary gene expression of TNFα and KC, but not their plasma levels, and enhanced Nrf2-induced pulmonary antioxidant defences. In Nrf2 deficient mice, no effect of the dietary antioxidant on either histology or inflammatory lesions was observed. Conclusion Quercetin exerts anti-fibrogenic and anti-inflammatory effects on bleomycin-induced pulmonary damage in mice possibly through modulation of the redox balance by inducing Nrf2. However, quercetin could not rescue the bleomycin-induced pulmonary damage indicating that quercetin alone cannot ameliorate the progression of IPF.


Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 604
Author(s):  
Ivan Orlandi ◽  
Lilia Alberghina ◽  
Marina Vai

Nicotinamide, nicotinic acid and nicotinamide riboside are vitamin B3 precursors of NAD+ in the human diet. NAD+ has a fundamental importance for cellular biology, that derives from its essential role as a cofactor of various metabolic redox reactions, as well as an obligate co-substrate for NAD+-consuming enzymes which are involved in many fundamental cellular processes including aging/longevity. During aging, a systemic decrease in NAD+ levels takes place, exposing the organism to the risk of a progressive inefficiency of those processes in which NAD+ is required and, consequently, contributing to the age-associated physiological/functional decline. In this context, dietary supplementation with NAD+ precursors is considered a promising strategy to prevent NAD+ decrease and attenuate in such a way several metabolic defects common to the aging process. The metabolism of NAD+ precursors and its impact on cell longevity have benefited greatly from studies performed in the yeast Saccharomyces cerevisiae, which is one of the most established model systems used to study the aging processes of both proliferating (replicative aging) and non-proliferating cells (chronological aging). In this review we summarize important aspects of the role played by nicotinamide, nicotinic acid and nicotinamide riboside in NAD+ metabolism and how each of these NAD+ precursors contribute to the different aspects that influence both replicative and chronological aging. Taken as a whole, the findings provided by the studies carried out in S. cerevisiae are informative for the understanding of the complex dynamic flexibility of NAD+ metabolism, which is essential for the maintenance of cellular fitness and for the development of dietary supplements based on NAD+ precursors.


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