scholarly journals Genomic Analysis Of NAD+ Synthesis Pathways Involved In Aging and Cancer

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 668-669
Author(s):  
Jeremy Meyers ◽  
Raul Castro-Portuguez ◽  
Luis Espejo ◽  
George Sutphin
Keyword(s):  
Mammalian Cells ◽  
De Novo ◽  
Sequence Data ◽  
Kynurenine Pathway ◽  
Metabolic Reprogramming ◽  
Apparent Contradiction ◽  
Continuous Growth ◽  
C Elegans ◽  
Age Related ◽  
Nad Synthesis

Abstract Cancer cells have elevated energy demands to sustain continuous growth and other malignant processes and undergo extensive metabolic reprogramming to meet these demands. One element of this reprogramming in many cancer subtypes is elevated synthesis of nicotinamide adenine dinucleotide (NAD+), a critical co-enzyme that supports energy production through both glycolysis and the TCA cycle. The kynurenine metabolic pathway is the evolutionarily conserved means by which cells produce NAD+ de novo from tryptophan. NAD+ levels drop with age, a contributing factor to many forms of age-related disease. While interventions that increase NAD+ have been shown to extend lifespan, previous work from our lab demonstrates that knockdown of several kynurenine pathway enzymes, thus decreasing de novo NAD+ production, results in increased longevity of Caenorhabditis elegans by 20-30%. To address this apparent contradiction, we propose that kynurenine pathway inhibition may produce metabolic feedback that results in upregulation of NAD+ recycling. Eukaryotic cells recycle NAD+ from nicotinamide (NAM) through one of two pathways: the Salvage pathway in mammalian cells and the Preiss-Handler pathway in C. elegans and related invertebrates species. We are using tools in C. elegans and human cell culture to examine the interaction between kynurenine/de novo NAD+ synthesis and NAD+ recycling through Salvage and Preiss-Handler. In particular, we are interested in how combining interventions between these pathways will influence activity throughout the NAD+ metabolic networks (measured via mass spectrometry), physiological phenotypes, and transcriptomic changes (via RNA sequence data) involved in aging and age-associated disease.

scholarly journals Inhibition of Kynurenine Metabolism and Its Effect in Mitochondrial Function in Hepatocellular Carcinoma

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 124-125
Author(s):  
Raul Castro-Portuguez ◽  
Samuel Freitas ◽  
George Sutphin
Keyword(s):  
Hepatocellular Carcinoma ◽  
Mitochondrial Function ◽  
De Novo ◽  
Principal Component ◽  
Kynurenine Pathway ◽  
The Cancer Genome Atlas ◽  
Wilcoxon Test ◽  
Nad Synthesis ◽  
Significant Difference ◽  
Kynurenine Metabolism

Abstract Hepatocellular carcinoma (HCC) is the most prevalent cancer in the liver. The majority of ingested tryptophan is processed in the liver through the kynurenine pathway, the endpoint of which is de novo NAD+ biosynthesis. Dysregulation of tryptophan-kynurenine metabolism and NAD+ synthesis may promote mitochondrial malfunction, tumor reprogramming, and carcinogenesis. Using a publicly available gene expression dataset from liver hepatocellular carcinoma (LIHC) samples available through The Cancer Genome Atlas (TCGA; n = 371), we employed Principal Component Analysis (PCA), hierarchical clustering, gene-pattern expression profiling, and survival analysis to cluster patients and determine overall survival. Our analysis of genes encoding kynurenine pathway enzymes determined that patients with high QPRT expression had a poor prognosis with decreased median survival, with no effect on the maximum survival. There is a significant difference in the survival between patients with high QPRT expression relative to patients with high HAAO/AFMID expression (HR = 1.2, [95% CI 0.5-1.8] P = 0.0181, Gehan-Breslow-Wilcoxon Test). Patients with high QPRT expression have higher survival rates compared with low QPRT expression (HR = 1.4, [95% CI 0.9-2.2] P = 0.0344, Gehan-Breslow-Wilcoxon Test). To test the consequences of kynurenine-pathway inhibition in mitochondrial function and morphology we use 4-Cl-3HAA, an irreversible HAAO inhibitor, and observed a small increase in mitochondrial fragmentation in HepG2 cells after 24 hours of treatment. We conclude that kynurenine metabolism may be useful as a biomarker to predict patient prognosis among HCC patients. In ongoing work, we are testing QPRT inhibitors in cell culture as a potential adjuvant for chemotherapies.

scholarly journals The Function of the Kynurenine Pathway in the Placenta: A Novel Pharmacotherapeutic Target?

2021 ◽  
Vol 18 (21) ◽  
pp. 11545
Author(s):  
Michelle Broekhuizen ◽  
A. H. Jan Danser ◽  
Irwin K. M. Reiss ◽  
Daphne Merkus
Keyword(s):  
Pregnancy Complications ◽  
De Novo ◽  
Recurrent Miscarriage ◽  
Fetal Loss ◽  
Kynurenine Pathway ◽  
Vascular Regulation ◽  
Exact Function ◽  
Nad Synthesis ◽  
Pregnant Mice ◽  
Rate Limiting

(L-)tryptophan is metabolized via the kynurenine pathway into several kynurenine metabolites with distinct functions. Dysfunction of the kynurenine pathway can lead to impairments in vascular regulation, immune regulation, and tolerance. The first and rate limiting enzyme of this pathway, indoleamine 2,3-dioxygenase (IDO), is highly expressed in the placenta and reduced in placentas from complicated pregnancies. IDO is essential during pregnancy, as IDO inhibition in pregnant mice resulted in fetal loss. However, the exact function of placental IDO, as well as its exact placental localization, remain controversial. This review identified that two isoforms of IDO; IDO1 and IDO2, are differently expressed between placental cells, suggesting spatial segregation. Furthermore, this review summarizes how the placental kynurenine pathway is altered in pregnancy complications, including recurrent miscarriage, preterm birth, preeclampsia, and fetal growth restriction. Importantly, we describe that these alterations do not affect maternally circulating metabolite concentrations, suggesting that the kynurenine pathway functions as a local signaling pathway. In the placenta, it is an important source of de novo placental NAD+ synthesis and regulates fetal tryptophan and kynurenine metabolite supply. Therefore, kynurenine pathway interventions might provide opportunities to treat pregnancy complications, and this review discusses how such treatment could affect placental function and pregnancy development.

scholarly journals Kynurenine Metabolism Lifespan Extension Mediated by Oxidative Stress Response and Hypoxic Response in C. elegans

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 684-684
Author(s):  
Raul Castro-Portuguez ◽  
Jeremy Meyers ◽  
Sam Freitas ◽  
Hope Dang ◽  
Emily Turner ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Transcription Factors ◽  
Stress Response ◽  
Aging Process ◽  
De Novo ◽  
Kynurenine Pathway ◽  
Oxidative Stress Response ◽  
Lifespan Extension ◽  
Hypoxic Stress ◽  
C Elegans

Abstract Aging is characterized by a progressive decline in the normal physiological functions of an organism, ultimately leading to mortality. Metabolic changes throughout the aging process disrupt the balance and homeostasis of the cell. The kynurenine metabolic pathway is the sole de novo biosynthetic pathway for producing NAD+ from ingested tryptophan. Altered kynurenine pathway activity is associated with both aging and a variety of age-associated diseases, and kynurenine-based interventions can extend lifespan in Caenorhabditis elegans. Our laboratory recently demonstrated knockdown of the kynurenine pathway enzymes kynureninase (KYNU) or 3-hydroxyanthranilic acid dioxygenase (HAAO) increases lifespan by 20-30% in C elegans. However, the mechanism of how these interventions may modulate response against different stressors during the aging process has yet to be explored. Fluorescent reporter strains show the stress-responsive transcription factors skn-1 (ortholog of NRF2/NFE2L2; oxidative stress response) and hif-1 (ortholog of HIF1A; hypoxic stress response) to be highly upregulated when the kynurenine pathway is inhibited. We also demonstrated the increase expression of gst-4 and gcs-1 (transcriptional targets skn-1), which are involved in production of the antioxidant glutathione (GSH), as well as upregulation of cysl-2 (transcriptional target of hif-1), a regulator of cysteine biosynthesis from serine. We hypothesize that lifespan extension resulting from kynurenine pathway inhibition is mediated, at least in part, by upregulation of these transcription factors, providing elevated defense against oxidative stress and hypoxic stress.

scholarly journals Hsp90 Stabilizes SIRT1 Orthologs in Mammalian Cells and C. elegans

2018 ◽  
Vol 19 (11) ◽  
pp. 3661 ◽  
Author(s):  
Minh Nguyen ◽  
Milán Somogyvári ◽  
Csaba Sőti
Keyword(s):  
Stress Responses ◽  
Mammalian Cells ◽  
Proteasomal Degradation ◽  
Sirtuin 1 ◽  
Physical Interaction ◽  
Dependent Manner ◽  
Hsp90 Inhibition ◽  
C Elegans ◽  
Age Related ◽  
Hsp 90

Sirtuin 1 (SIRT1) othologs are ubiquitous NAD+-dependent deacetylases that act as nutrient sensors and modulate metabolism and stress responses in diverse organisms. Both mammalian SIRT1 and Caenorhabditis elegans SIR-2.1 have been implicated in dietary restriction, longevity, and healthspan. Hsp90 is an evolutionarily conserved molecular chaperone that stabilizes a plethora of signaling ’client’ proteins and regulates fundamental biological processes. Here we report that Hsp90 is required for conformational stabilization of SIRT1 and SIR-2.1. We find that inhibition of Hsp90 by geldanamycin (GA) induces the depletion of mammalian SIRT1 protein in a concentration and time dependent manner in COS-7 and HepG2 cells. In contrast to SIRT1, SIRT2 level remains unchanged by GA treatment, reflecting a specific Hsp90 SIRT1 interaction. Hsp90 inhibition leads to the destabilization and proteasomal degradation of SIRT1. Moreover, we observe a GA-sensitive physical interaction between SIRT1 and Hsp90 by immunoprecipitation. We also demonstrate that hsp-90 gene silencing also induces SIR-2.1 protein depletion and proteasomal degradation in C. elegans. Our findings identify metazoan SIRT1 orthologs as Hsp90 clients and reveal a novel crosstalk between the proteostasis and nutrient signaling networks, which may have implications in various age related diseases.

scholarly journals Inhibition of the neuromuscular acetylcholine receptor with atracurium activates FOXO/DAF-16-induced longevity

2020 ◽  
Author(s):  
Rebecca L. McIntyre ◽  
Simone W. Denis ◽  
Rashmi Kamble ◽  
Michael Petr ◽  
Bauke V. Schomakers ◽  
...  
Keyword(s):  
Acetylcholine Receptor ◽  
Nuclear Localization ◽  
Mammalian Cells ◽  
C Elegans ◽  
Transcriptional Signature ◽  
Related Disease ◽  
Age Related ◽  
Downstream Effectors ◽  
Downstream Effects ◽  
Transcriptome Database

AbstractTranscriptome-based drug screening is emerging as a powerful tool to identify geroprotective compounds to intervene in age-related disease. We hypothesized that, by mimicking the transcriptional signature of the highly conserved longevity intervention of FOXO3 (daf-16 in worms) overexpression, we could identify and repurpose compounds with similar downstream effects to increase longevity. Our in silico screen, utilizing the LINCS transcriptome database of genetic and compound interventions, identified several FDA-approved compounds that activate FOXO downstream targets in mammalian cells. These included the neuromuscular blocker atracurium, which also robustly extends both lifespan and healthspan in C. elegans. This longevity is dependent on both daf-16 signaling and inhibition of the neuromuscular acetylcholine receptor. Other neuromuscular blockers tubocurarine and pancuronium caused similar healthspan benefits. We demonstrate nuclear localization of DAF-16 upon atracurium treatment, and, using RNAseq transcriptomics, identify activation of DAF-16 downstream effectors. Together, these data demonstrate the capacity to mimic genetic lifespan interventions with drugs, and in doing so, reveal that the neuromuscular acetylcholine receptor regulates the highly conserved FOXO/DAF-16 longevity pathway.

scholarly journals Whole genome sequencing and assembly of a Caenorhabditis elegans genome with complex genomic rearrangements using the MinION sequencing device

2017 ◽  
Author(s):  
JR Tyson ◽  
NJ O’Neil ◽  
M Jain ◽  
HE Olsen ◽  
P Hieter ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Genome Assembly ◽  
De Novo ◽  
Sequence Data ◽  
Genomic Rearrangements ◽  
Whole Genome ◽  
C Elegans ◽  
Long Reads

ABSTRACTAdvances in 3rd generation sequencing have opened new possibilities for ‘benchtop’ whole genome sequencing. The MinION is a portable device that uses nanopore technology and can sequence long DNA molecules. MinION long reads are well suited for sequencing and de novo assembly of complex genomes with large repetitive elements. Long reads also facilitate the identification of complex genomic rearrangements such as those observed in tumor genomes. To assess the feasibility of the de novo assembly of large complex genomes using both MinION and Illumina platforms, we sequenced the genome of a Caenorhabditis elegans strain that contains a complex acetaldehyde-induced rearrangement and a biolistic bombardment-mediated insertion of a GFP containing plasmid. Using ∼5.8 gigabases of MinION sequence data, we were able to assemble a C. elegans genome containing 145 contigs (N50 contig length = 1.22 Mb) that covered >99% of the 100,286,401 bp reference genome. In contrast, using ∼8.04 gigabases of Illumina sequence data, we were able to assemble a C. elegans genome in 38,645 contigs (N50 contig length = ∼26 kb) containing 117 Mb. From the MinION genome assembly we identified the complex structures of both the acetaldehyde-induced mutation and the biolistic-mediated insertion. To date, this is the largest genome to be assembled exclusively from MinION data and is the first demonstration that the long reads of MinION sequencing can be used for whole genome assembly of large (100 Mb) genomes and the elucidation of complex genomic rearrangements.

scholarly journals Histone deacetylase HDA-1 modulates mitochondrial stress response and longevity

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Li-Wa Shao ◽  
Qi Peng ◽  
Mingyue Dong ◽  
Kaiyu Gao ◽  
Yumei Li ◽  
...  
Keyword(s):  
Histone Deacetylase ◽  
Mammalian Cells ◽  
Metabolic Reprogramming ◽  
Mitochondrial Stress ◽  
C Elegans ◽  
Unfolded Protein ◽  
Mitochondrial Homeostasis ◽  
Evolutionarily Conserved ◽  
Protein Response ◽  
Mitochondrial Unfolded Protein Response

Abstract The ability to detect, respond and adapt to mitochondrial stress ensures the development and survival of organisms. Caenorhabditis elegans responds to mitochondrial stress by activating the mitochondrial unfolded protein response (UPRmt) to buffer the mitochondrial folding environment, rewire the metabolic state, and promote innate immunity and lifespan extension. Here we show that HDA-1, the C. elegans ortholog of mammalian histone deacetylase (HDAC) is required for mitochondrial stress-mediated activation of UPRmt. HDA-1 interacts and coordinates with the genome organizer DVE-1 to induce the transcription of a broad spectrum of UPRmt, innate immune response and metabolic reprogramming genes. In rhesus monkey and human tissues, HDAC1/2 transcript levels correlate with the expression of UPRmt genes. Knocking down or pharmacological inhibition of HDAC1/2 disrupts the activation of the UPRmt and the mitochondrial network in mammalian cells. Our results underscore an evolutionarily conserved mechanism of HDAC1/2 in modulating mitochondrial homeostasis and regulating longevity.

scholarly journals Alterations in Kynurenine and NAD+ Salvage Pathways during the Successful Treatment of Inflammatory Bowel Disease Suggest HCAR3 and NNMT as Potential Drug Targets

2021 ◽  
Vol 22 (24) ◽  
pp. 13497
Author(s):  
Artur Wnorowski ◽  
Sylwia Wnorowska ◽  
Jacek Kurzepa ◽  
Jolanta Parada-Turska
Keyword(s):  
Inflammatory Bowel Disease ◽  
Successful Treatment ◽  
Bowel Disease ◽  
Drug Targets ◽  
De Novo ◽  
Meta Analysis ◽  
Kynurenine Pathway ◽  
Infliximab Treatment ◽  
Nad Synthesis ◽  
Inflammatory Bowel

A meta-analysis of publicly available transcriptomic datasets was performed to identify metabolic pathways profoundly implicated in the progression and treatment of inflammatory bowel disease (IBD). The analysis revealed that genes involved in tryptophan (Trp) metabolism are upregulated in Crohn’s disease (CD) and ulcerative colitis (UC) and return to baseline after successful treatment with infliximab. Microarray and mRNAseq profiles from multiple experiments confirmed that enzymes responsible for Trp degradation via the kynurenine pathway (IDO1, KYNU, IL4I1, KMO, and TDO2), receptor of Trp metabolites (HCAR3), and enzymes catalyzing NAD+ turnover (NAMPT, NNMT, PARP9, CD38) were synchronously coregulated in IBD, but not in intestinal malignancies. The modeling of Trp metabolite fluxes in IBD indicated that changes in gene expression shifted intestinal Trp metabolism from the synthesis of 5-hydroxytryptamine (5HT, serotonin) towards the kynurenine pathway. Based on pathway modeling, this manifested in a decline in mucosal Trp and elevated kynurenine (Kyn) levels, and fueled the production of downstream metabolites, including quinolinate, a substrate for de novo NAD+ synthesis. Interestingly, IBD-dependent alterations in Trp metabolites were normalized in infliximab responders, but not in non-responders. Transcriptomic reconstruction of the NAD+ pathway revealed an increased salvage biosynthesis and utilization of NAD+ in IBD, which normalized in patients successfully treated with infliximab. Treatment-related changes in NAD+ levels correlated with shifts in nicotinamide N-methyltransferase (NNMT) expression. This enzyme helps to maintain a high level of NAD+-dependent proinflammatory signaling by removing excess inhibitory nicotinamide (Nam) from the system. Our analysis highlights the prevalent deregulation of kynurenine and NAD+ biosynthetic pathways in IBD and gives new impetus for conducting an in-depth examination of uncovered phenomena in clinical studies.

scholarly journals Targeting kynurenine metabolism to reduce inflammation and enhance stress response during aging

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 686-687
Author(s):  
George Sutphin ◽  
Hope Dang ◽  
Luis Espejo ◽  
Raul Castro-Portuguez ◽  
Bradford Hull ◽  
...  
Keyword(s):  
Stress Response ◽  
De Novo ◽  
Preliminary Evidence ◽  
Kynurenine Pathway ◽  
Cellular Stress Response ◽  
C Elegans ◽  
Extended Lifespan ◽  
Kynurenine Metabolism ◽  
Hydroxyanthranilic Acid ◽  
The Impact

Abstract Aberrant kynurenine pathway metabolism is increasingly linked to aging and age-associated disease. Kynurenine metabolic activity increases with age and becomes dysregulated during various forms of age-associated pathology in humans. By manipulating one or more kynurenine pathway enzymes and metabolites, we have extended lifespan up to 40% in Caenorhabditis elegans. In particular, elevating physiological levels of the kynurenine pathway metabolite 3-hydroxyanthranilic acid (3HAA) by directly supplementing 3HAA or inhibiting the enzyme 3HAA dioxygenase (HAAO) extends C. elegans lifespan by ~30%. 3HAA delivered chronically in chow similarly extends lifespan in aged C57BL/6 mice. In ongoing work, we are investigating the mechanisms underlying the benefits of multiple kynurenine pathway interventions using tools in C. elegans, mice, and human cell culture. We have preliminary evidence for activation of broad-spectrum cellular stress response, enhanced immune function, and reduced inflammation. Among other roles, the kynurenine pathway is the sole metabolic route for de novo synthesis of nicotinamide adenine dinucleotide (NAD+) from tryptophan in Eukaryotic cells. We are examining the regulatory interaction between kynurenine metabolism and the two NAD+ recycling pathways, Salvage and Preiss-Handler, both as potential mechanistic mediators and as possible parallel targets for combined interventions with synergistic benefits in aging. We are further evaluating the impact of these interventions in several models of specific age-associated diseases, including sepsis, chronic inflammation, stroke, Alzheimer’s disease, and cancer. Finally, we are developing pharmaceutical strategies to replicate key genetic and metabolic interventions within the kynurenine pathway that can be readily translated into clinical applications.

scholarly journals Phosphoglycolate phosphatase homologs act as glycerol-3-phosphate phosphatase to control stress and healthspan in C. elegans

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Elite Possik ◽  
Clémence Schmitt ◽  
Anfal Al-Mass ◽  
Ying Bai ◽  
Laurence Côté ◽  
...  
Keyword(s):  
Calorie Restriction ◽  
Mammalian Cells ◽  
Healthy Aging ◽  
Model Organism ◽  
Metabolic Stress ◽  
Clinical Importance ◽  
C Elegans ◽  
Beneficial Effects ◽  
Age Related

AbstractMetabolic stress due to nutrient excess and lipid accumulation is at the root of many age-associated disorders and the identification of therapeutic targets that mimic the beneficial effects of calorie restriction has clinical importance. Here, using C. elegans as a model organism, we study the roles of a recently discovered enzyme at the heart of metabolism in mammalian cells, glycerol-3-phosphate phosphatase (G3PP) (gene name Pgp) that hydrolyzes glucose-derived glycerol-3-phosphate to glycerol. We identify three Pgp homologues in C. elegans (pgph) and demonstrate in vivo that their protein products have G3PP activity, essential for glycerol synthesis. We demonstrate that PGPH/G3PP regulates the adaptation to various stresses, in particular hyperosmolarity and glucotoxicity. Enhanced G3PP activity reduces fat accumulation, promotes healthy aging and acts as a calorie restriction mimetic at normal food intake without altering fertility. Thus, PGP/G3PP can be considered as a target for age-related metabolic disorders.

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