Medicine and Health Sciences Commons^™

Gut Microbial Trimethylamine Is Elevated In Alcohol-Associated Hepatitis And Contributes To Ethanol-Induced Liver Injury In Mice, Robert N. Helsley, Tatsunori Miyata, Anagha Kadam, Venkateshwari Varadharajan, Naseer Sangwan, Emily C. Huang, Rakhee Banerjee, Amanda L. Brown, Kevin K. Fung, William J. Massey, Chase Neumann, Danny Orabi, Lucas J. Osborn, Rebecca C. Schugar, Megan R. Mcmullen, Annette Bellar, Kyle L. Poulsen, Adam Kim, Vai Pathak, Marko Mrdjen

Pediatrics Faculty Publications

There is mounting evidence that microbes residing in the human intestine contribute to diverse alcohol-associated liver diseases (ALD) including the most deadly form known as alcohol-associated hepatitis (AH). However, mechanisms by which gut microbes synergize with excessive alcohol intake to promote liver injury are poorly understood. Furthermore, whether drugs that selectively target gut microbial metabolism can improve ALD has never been tested. We used liquid chromatography tandem mass spectrometry to quantify the levels of microbe and host choline co-metabolites in healthy controls and AH patients, finding elevated levels of the microbial metabolite trimethylamine (TMA) in AH. In subsequent studies, we …

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 …

Aberrant Azin2 And Polyamine Metabolism Precipitates Tau Neuropathology, Leslie A. Sandusky-Beltran, Andrii Kovalenko, Devon S. Placides, Kevin Ratnasamy, Chao Ma, Jerry B. Hunt, Huimin Liang, John Ivan T. Calahatian, Camilla Michalski, Margaret Fahnestock, Laura J. Blair, April L. Darling, Jeremy D. Baker, Sarah N. Fontaine, Chad A. Dickey, Joshua J. Gamsby, Kevin R. Nash, Erin L. Abner, Maj-Linda B. Selenica, Daniel C. Lee

Sanders-Brown Center on Aging Faculty Publications

Tauopathies display a spectrum of phenotypes from cognitive to affective behavioral impairments; however, mechanisms promoting tau pathology and how tau elicits behavioral impairment remain unclear. We report a unique interaction between polyamine metabolism, behavioral impairment, and tau fate. Polyamines are ubiquitous aliphatic molecules that support neuronal function, axonal integrity, and cognitive processing. Transient increases in polyamine metabolism hallmark the cell’s response to various insults, known as the polyamine stress response (PSR). Dysregulation of gene transcripts associated with polyamine metabolism in Alzheimer’s disease (AD) brains were observed, and we found that ornithine decarboxylase antizyme inhibitor 2 (AZIN2) increased to …

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).

Mitochondria Exert Age-Divergent Effects On Recovery From Spinal Cord Injury, Andrew N. Stewart, Katelyn E. Mcfarlane, Hemendra J. Vekaria, William M. Bailey, Stacey A. Slone, Lauren A. Tranthem, Bei Zhang, Samir P. Patel, Patrick G. Sullivan, John C. Gensel

Physiology Faculty Publications

The extent that age-dependent mitochondrial dysfunction drives neurodegeneration is not well understood. This study tested the hypothesis that mitochondria contribute to spinal cord injury (SCI)-induced neurodegeneration in an age-dependent manner by using 2,4-dinitrophenol (DNP) to uncouple electron transport, thereby increasing cellular respiration and reducing reactive oxygen species (ROS) production. We directly compared the effects of graded DNP doses in 4- and 14-month-old (MO) SCI-mice and found DNP to have increased efficacy in mitochondria isolated from 14-MO animals. In vivo, all DNP doses significantly exacerbated 4-MO SCI neurodegeneration coincident with worsened recovery. In contrast, low DNP doses (1.0-mg/kg/day) improved tissue …

Palbociclib Treatment Alters Nucleotide Biosynthesis And Glutamine Dependency In A549 Cells, Lindsey R. Conroy, Pawel Lorkiewicz, Liqing He, Xinmin Yin, Xiang Zhang, Shesh N. Rai, Brian F. Clem

Neuroscience Faculty Publications

Background

Aberrant activity of cell cycle proteins is one of the key somatic events in non-small cell lung cancer (NSCLC) pathogenesis. In most NSCLC cases, the retinoblastoma protein tumor suppressor (RB) becomes inactivated via constitutive phosphorylation by cyclin dependent kinase (CDK) 4/6, leading to uncontrolled cell proliferation. Palbociclib, a small molecule inhibitor of CDK4/6, has shown anti-tumor activity in vitro and in vivo, with recent studies demonstrating a functional role for palbociclib in reprogramming cellular metabolism. While palbociclib has shown efficacy in preclinical models of NSCLC, the metabolic consequences of CDK4/6 inhibition in this context are largely unknown.

Methods

In …

Postnatal Loss Of The Insulin Receptor In Osteoprogenitor Cells Does Not Impart A Metabolic Phenotype, John L. Fowlkes, R. Clay Bunn, Evangelia Kalaitzoglou, Phil Ray, Iuliana Popescu, Kathryn M. Thrailkill

Barnstable Brown Diabetes Center Faculty Publications

The relationship between osteoblast-specific insulin signaling, osteocalcin activation and gluco-metabolic homeostasis has proven to be complex and potentially inconsistent across animal-model systems and in humans. Moreover, the impact of postnatally acquired, osteoblast-specific insulin deficiency on the pancreas-to-skeleton-to-pancreas circuit has not been studied. To explore this relationship, we created a model of postnatal elimination of insulin signaling in osteoprogenitors. Osteoprogenitor-selective ablation of the insulin receptor was induced after ~10 weeks of age in IR^l°^x/lox/Osx-Cre^+/− genotypic male and female mice (designated postnatal-OIRKO). At ~21 weeks of age, mice were then phenotypically and metabolically characterized. Postnatal-OIRKO mice demonstrated …

Microrna-148a Regulates Low-Density Lipoprotein Metabolism By Repressing The (Pro)Renin Receptor, Na Wang, Lishu He, Hui Lin, Lunbo Tan, Yuan Sun, Xiaoying Zhang, A. H. Jan Danser, Hong S. Lu, Yongcheng He, Xifeng Lu

Saha Cardiovascular Research Center Faculty Publications

High plasma LDL cholesterol (LDL-c) concentration is a major risk factor for atherosclerosis. Hepatic LDL receptor (LDLR) regulates LDL metabolism, and thereby plasma LDL-c concentration. Recently, we have identified the (pro)renin receptor [(P)RR] as a novel regulator of LDL metabolism, which regulates LDLR degradation and hence its protein abundance and activity. In silico analysis suggests that the (P)RR is a target of miR-148a. In this study we determined whether miR-148a could regulate LDL metabolism by regulating (P)RR expression in HepG2 and Huh7 cells. We found that miR-148a suppressed (P)RR expression by binding to the 3’-untranslated regions (3’-UTR) of the (P)RR …

Hdl Subclass Proteomic Analysis And Functional Implication Of Protein Dynamic Change During Hdl Maturation, Yuling Zhang, Scott M. Gordon, Hang Xi, Seungbum Choi, Merlin Abner Paz, Runlu Sun, William Yang, Jason Saredy, Mohsin Khan, Alan Thomas Remaley, Jing-Feng Wang, Xiaofeng Yang, Hong Wang

Saha Cardiovascular Research Center Faculty Publications

Recent clinical trials reported that increasing high-density lipoprotein-cholesterol (HDL-C) levels does not improve cardiovascular outcomes. We hypothesize that HDL proteome dynamics determine HDL cardioprotective functions. In this study, we characterized proteome profiles in HDL subclasses and established their functional connection. Mouse plasma was fractionized by fast protein liquid chromatography, examined for protein, cholesterial, phospholipid and trigliceride content. Small, medium and large (S/M/L)-HDL subclasseses were collected for proteomic analysis by mass spectrometry. Fifty-one HDL proteins (39 in S-HDL, 27 in M-HDL and 29 in L-HDL) were identified and grouped into 4 functional categories (lipid metabolism, immune response, coagulation, and others). Eleven …

Type 1 Diabetes Alters Lipid Handling And Metabolism In Human Fibroblasts And Peripheral Blood Mononuclear Cells, Albert R. Jones Iv, Emily L. Coleman, Nicholas R. Husni, Jude T. Deeney, Forum Raval, Devin Steenkamp, Hans Dooms, Barbara S. Nikolajczyk, Barbara E. Corkey

Clinical and Translational Science Faculty Publications

Triggers of the autoimmune response that leads to type 1 diabetes (T1D) remain poorly understood. A possibility is that parallel changes in both T cells and target cells provoke autoimmune attack. We previously documented greater Ca²⁺ transients in fibroblasts from T1D subjects than non-T1D after exposure to fatty acids (FA) and tumor necrosis factor α (TNFα). These data indicate that metabolic and signal transduction defects present in T1D can be elicited ex vivo in isolated cells. Changes that precede T1D, including inflammation, may activate atypical responses in people that are genetically predisposed to T1D. To identify such cellular differences …

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.

Energizing Mirna Research: A Review Of The Role Of Mirnas In Lipid Metabolism, With A Prediction That Mir-103/107 Regulates Human Metabolic Pathways, Bernard R. Wilfred, Wang-Xia Wang, Peter T. Nelson

Sanders-Brown Center on Aging Faculty Publications

MicroRNAs (miRNAs) are powerful regulators of gene expression. Although first discovered in worm larvae, miRNAs play fundamental biological roles-including in humans-well beyond development. MiRNAs participate in the regulation of metabolism (including lipid metabolism) for all animal species studied. A review of the fascinating and fast-growing literature on miRNA regulation of metabolism can be parsed into three main categories: (1) adipocyte biochemistry and cell fate determination; (2) regulation of metabolic biochemistry in invertebrates; and (3) regulation of metabolic biochemistry in mammals. Most research into the 'function' of a given miRNA in metabolic pathways has concentrated on a given miRNA acting upon …