Medicine and Health Sciences Commons^™

Apoε4 Lowers Energy Expenditure In Females And Impairs Glucose Oxidation By Increasing Flux Through Aerobic Glycolysis, Brandon C. Farmer, Holden C. Williams, Nicholas A. Devanney, Margaret A. Piron, Grant K. Nation, David J. Carter, Adeline E. Walsh, Rebika Khanal, Lyndsay E. A. Young, Jude C. Kluemper, Gabriela Hernandez, Elizabeth J. Allenger, Rachel Mooney, Lesley R. Golden, Cathryn T. Smith, J. Anthony Brandon, Vedant A. Gupta, Philip A. Kern, Matthew S. Gentry, Josh M. Morganti, Ramon C. Sun, Lance A. Johnson

Physiology Faculty Publications

BACKGROUND: Cerebral glucose hypometabolism is consistently observed in individuals with Alzheimer's disease (AD), as well as in young cognitively normal carriers of the Ε4 allele of Apolipoprotein E (APOE), the strongest genetic predictor of late-onset AD. While this clinical feature has been described for over two decades, the mechanism underlying these changes in cerebral glucose metabolism remains a critical knowledge gap in the field.

METHODS: Here, we undertook a multi-omic approach by combining single-cell RNA sequencing (scRNAseq) and stable isotope resolved metabolomics (SIRM) to define a metabolic rewiring across astrocytes, brain tissue, mice, and human subjects expressing APOE4.

RESULTS: Single-cell …

A Computational Analysis Of Selective Metabolism Of Bupropion By Cytochrome P450 2b6, Alyssa Santos

Honors Scholar Theses

Bupropion is an antidepressant and smoking cessation aid that is extensively metabolized by cytochrome P450 (CYP) 2B6. It is a highly lipophilic chiral drug that undergoes stereoselective metabolism with preference for the (S)-enantiomer. Despite chemical reasons for why bupropion can be metabolized by other CYP isozymes, clinically, bupropion is preferentially metabolized by CYP2B6, and at certain concentrations, CYP2E1, CYP2C19, and CYP3A4. A computational analysis with simulated molecular docking was performed using two different scoring algorithms to analyze the specific amino acid interactions between bupropion and various CYP isozymes. Trials were run using one stereoisomer of bupropion (R …

Regional N-Glycan And Lipid Analysis From Tissues Using Maldi-Mass Spectrometry Imaging, Alexandra E. Stanback, Lindsey R. Conroy, Lyndsay E. A. Young, Tara R. Hawkinson, Kia H. Markussen, Harrison A. Clarke, Derek B. Allison, Ramon C. Sun

Neuroscience Faculty Publications

N-glycans and lipids are structural metabolites that play important roles in cellular processes. Both show unique regional distribution in tissues; therefore, spatial analyses of these metabolites are crucial to our understanding of cellular physiology. Matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) is an innovative technique that enables in situ detection of analytes with spatial distribution. This workflow details a MALDI-MSI protocol for the spatial profiling of N-glycans and lipids from tissues following application of enzyme and MALDI matrix.

For complete details on the use and execution of this protocol, please refer to Drake et al. (2018) and Andres et al. (2020).

Mitochondrial Metabolism In Major Neurological Diseases, Zhengqiu Zhou, Grant L. Austin, Lyndsay E. A. Young, Lance A. Johnson, Ramon Sun

Molecular and Cellular Biochemistry Faculty Publications

Mitochondria are bilayer sub-cellular organelles that are an integral part of normal cellular physiology. They are responsible for producing the majority of a cell’s ATP, thus supplying energy for a variety of key cellular processes, especially in the brain. Although energy production is a key aspect of mitochondrial metabolism, its role extends far beyond energy production to cell signaling and epigenetic regulation–functions that contribute to cellular proliferation, differentiation, apoptosis, migration, and autophagy. Recent research on neurological disorders suggest a major metabolic component in disease pathophysiology, and mitochondria have been shown to be in the center of metabolic dysregulation and possibly …

Mitochondrial Reactive Oxygen Species In Lipotoxic Hearts Induces Post-Translational Modifications Of Akap121, Drp1 And Opa1 That Promote Mitochondrial Fission, Kensuke Tsushima, Heiko Bugger, Adam R. Wende, Jamie Soto, Gregory A. Jenson, Austin R. Tor, Rose Mcglauflin, Helena C. Kenny, Yuan Zhang, Rhonda Souvenir, Xiao X. Hu, Crystal L. Sloan, Renata O. Pereira, Vitor A. Lira, Kenneth W. Spitzer, Terry L. Sharp, Kooresh I. Shoghi, Genevieve C. Sparagna, Eva A. Rog-Zielinska, Peter Kohl, Oleh Khalimonchuk, Jean E. Schaffer, E. Dale Abel

Department of Biochemistry: Faculty Publications

Rationale: Cardiac lipotoxicity, characterized by increased uptake, oxidation and accumulation of lipid intermediates, contributes to cardiac dysfunction in obesity and diabetes. However, mechanisms linking lipid overload and mitochondrial dysfunction are incompletely understood.

Objective: To elucidate the mechanisms for mitochondrial adaptations to lipid overload in postnatal hearts in vivo.

Methods and Results: Using a transgenic mouse model of cardiac lipotoxicity overexpressing long-chain acyl-CoA synthetase 1 in cardiomyocytes, we show that modestly increased myocardial fatty acid uptake leads to mitochondrial structural remodeling with significant reduction in minimum diameter. This is associated with increased palmitoyl-carnitine oxidation and increased reactive oxygen species (ROS) generation …

Exploring Cancer Metabolism Using Stable Isotope-Resolved Metabolomics (Sirm), Ronald C. Bruntz, Andrew N. Lane, Richard M. Higashi, Teresa W. -M. Fan

Center for Environmental and Systems Biochemistry Faculty Publications

Metabolic reprogramming is a hallmark of cancer. The changes in metabolism are adaptive to permit proliferation, survival, and eventually metastasis in a harsh environment. Stable isotope-resolved metabolomics (SIRM) is an approach that uses advanced approaches of NMR and mass spectrometry to analyze the fate of individual atoms from stable isotope-enriched precursors to products to deduce metabolic pathways and networks. The approach can be applied to a wide range of biological systems, including human subjects. This review focuses on the applications of SIRM to cancer metabolism and its use in understanding drug actions.

Bioengineered Lysozyme Reduces Bacterial Burden And Inflammation In A Murine Model Of Mucoid Pseudomonas Aeruginosa Lung Infection, Charlotte C. Teneback, Thomas C. Scanlon, Matthew J. Wargo, Jenna L. Bement, Karl E. Griswold, Laurie W. Leclair

Dartmouth Scholarship

The spread of drug-resistant bacterial pathogens is a growing global concern and has prompted an effort to explore potential adjuvant and alternative therapies derived from nature's repertoire of bactericidal proteins and peptides. In humans, the airway surface liquid layer is a rich source of antibiotics, and lysozyme represents one of the most abundant and effective antimicrobial components of airway secretions. Human lysozyme is active against both Gram-positive and Gram-negative bacteria, ac

Acute Fatty Liver Of Pregnancy: An Update On Mechanisms, Sathish Kumar Natarajan, Kavitha R. Thangaraj, Ashish Goel, C. E. Eapen, K. A. Balasubramanian, Anup Ramachandran

School of Veterinary and Biomedical Sciences: Faculty Publications

Acute fatty liver of pregnancy (AFLP), characterized by hepatic microvesicular steatosis, is a sudden catastrophic illness occurring almost exclusively in the third trimester of pregnancy. Defective fatty acid oxidation in the fetus has been shown to be associated with this disease. Since the placenta has the same genetic makeup as the fetus and as AFLP patients generally recover following delivery, we hypothesized that the placenta might be involved in pathogenesis of this disease. In an animal model of hepatic microvesicular steatosis (using sodium valproate), we found that microvesicular steatosis results in mitochondrial structural alterations and oxidative stress in subcellular organelles …

Microbial Nad Metabolism: Lessons From Comparative Genomics, Francesca Gazzaniga, Rebecca Stebbins, Sheila Z. Chang, Mark A. Mcpeek, Charles Brenner

Dartmouth Scholarship

NAD is a coenzyme for redox reactions and a substrate of NAD-consuming enzymes, including ADP-ribose transferases, Sir2-related protein lysine deacetylases, and bacterial DNA ligases. Microorganisms that synthesize NAD from as few as one to as many as five of the six identified biosynthetic precursors have been identified. De novo NAD synthesis from aspartate or tryptophan is neither universal nor strictly aerobic. Salvage NAD synthesis from nicotinamide, nicotinic acid, nicotinamide riboside, and nicotinic acid riboside occurs via modules of different genes. Nicotinamide salvage genes nadV and pncA, found in distinct bacteria, appear to have spread throughout the tree of life …

Differential Regulation Of Collagenase Gene Expression By Retinoic Acid Receptors--Alpha, Beta And Gamma, Luying Pan, Stephen H. Chamberlain, David T. Auble, Constance E. Brinckerhoff

Dartmouth Scholarship

The mechanisms involved in retinoic acid (RA)-mediated regulation of the collagenase gene in a rabbit synovial fibroblast cell line (HIG82) were investigated. When HIG82 cells are cotransfected with expression vectors containing cDNAs for retinoic acid receptor (RAR) α1, β2, or γ1 and collagenase promoter-driven CAT reporter constructs, only RAR-γ1 represses basal CAT expression upon RA treatment, while RAR-α1, β2, and γ1 all suppress phorbol-induced CAT expression. Thus, transcriptional regulation of collagenase by RA is mediated by RARs in an RAR-type specific manner. Using mutatlonal and deletional analysis, we find that interaction between elements within 182 bp collagenase promoter plays an …