Expression analysis upon NAMPT knockdown in MCF-7 cells
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE13449 | GEO | 2009/05/28
SECONDARY ACCESSION(S): PRJNA113977
REPOSITORIES: GEO
Similar Datasets
Project description:NAMPT is an enzyme in the mammalian NAD+ salvage pathway. Expression microarray analysis was used to study the effect of NAMPT knockdown on gene expression in MCF-7 breast cancer cells. Experiment Overall Design: Stable knockdown of NAMPT was achieved using a retroviral shRNA construct. An shRNA directed against Luciferase was used to generate the Luc control cells. Three independent biological replicates with matching Luc controls were analyzed using Affymetrix U133 A2.0 microarrays.
2009-06-08 | E-GEOD-13449 | biostudies-arrayexpress
Project description:NMNAT1 is a nuclear enzyme in the mammalian NAD+ salvage pathway. Expression microarray analysis was used to study the effect of NMNAT1 knockdown on gene expression in MCF-7 breast cancer cells.
2009-05-28 | GSE13458 | GEO
Project description:Neural stem/progenitor cell (NSPC) proliferation and self-renewal, as well as insult-induced differentiation, decrease markedly with age, but the molecular mechanisms responsible for these declines remain unclear. Here we show that levels of NAD+ and nicotinamide phosphoribosyltransferase (Nampt), the rate-limiting enzyme in mammalian NAD+ biosynthesis, decrease with age in the hippocampus. Ablation of Nampt in adult NSPCs reduced their pool and proliferation in vivo. The decrease in the NSPC pool during aging can be rescued by enhancing hippocampal NAD+ levels. Nampt is the main source of NSPC NAD+ levels and required for G1/S progression of the NSPC cell cycle. Nampt is also critical for oligodendrocytic lineage fate decisions through a mechanism mediated redundantly by Sirt1 and Sirt2. Ablation of Nampt in the adult NSPCs in vivo reduced NSPC-mediated oligodendrogenesis upon injury. These phenotypes recapitulate defects in NSPCs during aging, implicating Nampt-mediated NAD+ biosynthesis as a mediator of these age-associated functional declines. Total RNA obtained from neurospheres derived from postnatal hippocampi subjected to 48 hours in vitro of incubation with Nampt-specific inhibitor FK866 (10 nM, 4 samples) or vehicle (DMSO, 1:1000, 4 samples).
2014-05-08 | E-GEOD-49784 | biostudies-arrayexpress
Project description:Neural stem/progenitor cell (NSPC) proliferation and self-renewal, as well as insult-induced differentiation, decrease markedly with age, but the molecular mechanisms responsible for these declines remain unclear. Here we show that levels of NAD+ and nicotinamide phosphoribosyltransferase (Nampt), the rate-limiting enzyme in mammalian NAD+ biosynthesis, decrease with age in the hippocampus. Ablation of Nampt in adult NSPCs reduced their pool and proliferation in vivo. The decrease in the NSPC pool during aging can be rescued by enhancing hippocampal NAD+ levels. Nampt is the main source of NSPC NAD+ levels and required for G1/S progression of the NSPC cell cycle. Nampt is also critical for oligodendrocytic lineage fate decisions through a mechanism mediated redundantly by Sirt1 and Sirt2. Ablation of Nampt in the adult NSPCs in vivo reduced NSPC-mediated oligodendrogenesis upon injury. These phenotypes recapitulate defects in NSPCs during aging, implicating Nampt-mediated NAD+ biosynthesis as a mediator of these age-associated functional declines.
2014-05-08 | GSE49784 | GEO
Project description:As obligate intracellular pathogens, viruses often activate host metabolic enzymes to supply intermediates that support progeny production. Nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme of the salvage NAD+ synthesis, is an interferon-inducible protein that inhibits the replication of several RNA and DNA viruses with unknown mechanism. Here we report that NAMPT restricts herpes simplex virus 1 (HSV-1) replication via phosphoribosyl-hydrolase activity toward key viral structural proteins, independent of NAD+ synthesis. Deep mining of enriched phosphopeptides of HSV-1-infected cells identified phosphoribosylated viral structural proteins, particularly glycoproteins and tegument proteins. Indeed, NAMPT dephosphoribosylates viral proteins in vitro and in cells. Chimeric and recombinant HSV-1 carrying phosphoribosylation-resistant mutations show that phosphoribosylation promotes the incorporation of structural proteins into HSV-1 virions and subsequent virus entry. Moreover, loss of NAMPT renders mice highly susceptible to HSV-1 infection. The work describes a hidden enzyme activity of a metabolic enzyme in viral infection and host defense, offering a system to interrogate roles of phosphoribosylation in metazoans.
2024-09-13 | PXD050684 | Pride
Project description:Adoption of Warburg metabolism is critical for macrophage activation in response to lipopolysaccharide (LPS). Macrophages stimulated with LPS (without or with interferon-γ) increase expression of nicotinamide phosphoribosyltransferase (NAMPT), a key enzyme in NAD+ salvage, and loss of NAMPT activity alters their inflammatory potential. However, events leading to NAD+ salvage-dependence in these cells remain poorly defined. We show that NAD+ depletion and increased NAMPT expression occur rapidly after inflammatory activation and coincide with DNA damage caused by reactive oxygen species (ROS). ROS are produced by Complex III of the mitochondrial electron transport chain, and are required for macrophage activation. We show that DNA damage is associated with PARP activation, which results in NAD+ consumption and in this setting increased NAMPT expression allows the maintenance of NAD+ pools sufficient for GAPDH activity and Warburg metabolism. Our findings provide an integrated explanation for dependency on the NAD+ salvage pathway in inflammatory macrophages.
2019-03-06 | GSE123596 | GEO
Project description:NAD is an obligate co-factor for the catabolism of metabolic fuels in all cell types. However, the availability of NAD in several tissues can become limited during genotoxic stress and the course of natural aging. The point at which NAD restriction imposes functional limitations on tissue physiology remains unknown. We examined this question in murine skeletal muscle by specifically depleting Nampt, an essential enzyme in the NAD salvage pathway. Knockout mice exhibited a dramatic 85% decline in intramuscular NAD content, accompanied by fiber degeneration and progressive loss of both muscle strength and treadmill endurance. Administration of the NAD precursor nicotinamide riboside rapidly ameliorated functional deficits and restored muscle mass, despite having only a modest effect on the intramuscular NAD pool. Additionally, lifelong overexpression of Nampt preserved muscle NAD levels and exercise capacity in aged mice, supporting a critical role for tissue-autonomous NAD homeostasis in maintaining muscle mass and function. Messenger RNA was isolated from quadriceps muscle of mice from three different age groups and three different genotypes. Wildtype mice were aged 4, 7, and 24 months. Mice deficient for Nampt in skeletal muscle (mNKO) were aged 7 months. Mice overexpressing Nampt in skeletal muscle were aged 4 and 24 months.
2016-07-22 | E-GEOD-74570 | biostudies-arrayexpress
Project description:Molecular clocks in the periphery coordinate tissue-specific daily biorhythms by integrating input from the hypothalamic master clock and intracellular metabolic signals. One such key metabolic signal is the cellular concentration of NAD+, which oscillates along with its biosynthetic enzyme, nicotinamide phosphoribosyltransferase (NAMPT). NAD+ levels feed back into the clock to influence rhythmicity of biological functions, yet whether this metabolic fine-tuning occurs ubiquitously across cell types and is a core clock feature is unknown. Here we show that NAMPT-dependent control over the molecular clock varies substantially between tissues. Brown adipose tissue (BAT) requires NAMPT to sustain the amplitude of the core clock, whereas rhythmicity in white adipose tissue (WAT) is only moderately dependent on NAD+ biosynthesis and the skeletal muscle clock is completely refractory to loss of NAMPT. In BAT and WAT, NAMPT differentially orchestrates oscillation of clock-controlled gene networks and the diurnality of metabolite levels. NAMPT coordinates the rhythmicity of TCA cycle intermediates in BAT, but not WAT, and loss of NAD+ abolishes these oscillations similarly to high fat diet (HFD)-induced circadian disruption. Adipose NAMPT depletion also improved the ability of animals to defend body temperature during cold stress but this is independent of time-of-day. Thus, our findings reveal that peripheral molecular clocks and metabolic biorhythms are shaped in a highly tissue-specific manner by NAMPT-dependent NAD+ synthesis.
2023-04-11 | GSE221550 | GEO
Project description:Nicotinamide adenine dinucleotide (NAD), a cofactor for hundreds of metabolic reactions in all cell types, plays an essential role in diverse cellular processes including metabolism, DNA repair, and aging. NAD metabolism is critical to maintain cellular homeostasis in response to environmental signals, however, how it is impacted by the environment remains unclear. Here, we report an unexpected trans-kingdom cooperation between bacteria and mammalian cells wherein bacteria contribute to host NAD biosynthesis. Bacteria confer mammalian cells with the resistance to inhibitors of NAMPT, the rate limiting enzyme in the main vertebrate NAD salvage pathway. Mechanistically, a microbial nicotinamidase (PncA) that converts nicotinamide to nicotinic acid, a key precursor in the alternative deamidated NAD salvage pathway, is necessary and sufficient for this protective effect. This bacteria-enabled bypass of the pharmacologically induced metabolic block in mammalian cells represents a novel paradigm in drug resistance. This host-microbe metabolic interaction also dramatically enhances the hepatic NAD-boosting efficiency of nicotinamide and nicotinamide riboside supplementation, demonstrating a crucial role of microbes, gut microbiota in particular, in systemic NAD metabolism.
2020-03-03 | GSE127750 | GEO
Project description:Ovarian cancer follows a characteristic progression pattern, forming multiple tumor masses enriched with cancer stem cells (CSCs) within the abdomen. Most patients become resistant to standard platinum-based drugs, necessitating a change in treatment approach. To target CSCs, inhibiting NAMPT, which is the rate-limiting enzyme in the salvage pathway for NAD+ synthesis, has been explored. KPT-9274 is an innovative drug targeting both NAMPT and PAK4. However, its effectiveness against ovarian cancer had not been validated. Here, we show the efficacy and mechanisms of KPT-9274 in treating 3D-cultured spheroids that are resistant to platinum-based drugs. In these spheroids, KPT-9274 not only inhibited NAD+ production in NAMPT-dependent cell lines, but also suppressed NADPH and ATP production, indicating reduced mitochondrial function. It also downregulated expression of inflammation and gene repair-related genes. Moreover, by altering PAK4's mostly cytoplasmic localization, the compound hindered kinase activity, leading to decreased phosphorylation of S6 Ribosomal protein, AKT, and β-Catenin in the cytoplasm and its suppression was NAD+- dependent. These findings suggest that KPT-9274 could be a promising treatment for ovarian cancer patients resistant to platinum drugs, emphasizing the need for precision medicine to identify the specific NAD+-producing pathway a tumor relies on before treatment.
2024-03-14 | GSE251890 | GEO