Digital Commons Network^™

Tfeb And Tfe3 Control Glucose Homeostasis By Regulating Insulin Gene Expression, Adrien Pasquier, Nunzia Pastore, Luca D'Orsi, Rita Colonna, Alessandra Esposito, Veronica Maffia, Rossella De Cegli, Margherita Mutarelli, Susanna Ambrosio, Gennaro Tufano, Antonio Grimaldi, Marcella Cesana, Davide Cacchiarelli, Nathalie Delalleau, Gennaro Napolitano, Andrea Ballabio

Duncan NRI Faculty and Staff Publications

To fulfill their function, pancreatic beta cells require precise nutrient-sensing mechanisms that control insulin production. Transcription factor EB (TFEB) and its homolog TFE3 have emerged as crucial regulators of the adaptive response of cell metabolism to environmental cues. Here, we show that TFEB and TFE3 regulate beta-cell function and insulin gene expression in response to variations in nutrient availability. We found that nutrient deprivation in beta cells promoted TFEB/TFE3 activation, which resulted in suppression of insulin gene expression. TFEB overexpression was sufficient to inhibit insulin transcription, whereas beta cells depleted of both TFEB and TFE3 failed to suppress insulin gene …

Srcap Mutations Drive Clonal Hematopoiesis Through Epigenetic And Dna Repair Dysregulation, Chun-Wei Chen, Linda Zhang, Ravi Dutta, Abhishek Niroula, Peter G Miller, Christopher J Gibson, Alexander G Bick, Jaime M Reyes, Yi-Tang Lee, Ayala Tovy, Tianpeng Gu, Sarah Waldvogel, Yi-Hung Chen, Bryan J Venters, Pierre-Olivier Estève, Sriharsa Pradhan, Michael-Christopher Keogh, Pradeep Natarajan, Koichi Takahashi, Adam S Sperling, Margaret A Goodell

Faculty, Staff and Students Publications

Somatic mutations accumulate in all cells with age and can confer a selective advantage, leading to clonal expansion over time. In hematopoietic cells, mutations in a subset of genes regulating DNA repair or epigenetics frequently lead to clonal hematopoiesis (CH). Here, we describe the context and mechanisms that lead to enrichment of hematopoietic stem cells (HSCs) with mutations in SRCAP, which encodes a chromatin remodeler that also influences DNA repair. We show that SRCAP mutations confer a selective advantage in human cells and in mice upon treatment with the anthracycline-class chemotherapeutic doxorubicin and bone marrow transplantation. Furthermore, Srcap mutations lead …

Stop-Ad Portal: Selecting The Optimal Pharmaceutical For Preclinical Drug Testing In Alzheimer's Disease., Sara K Quinney, Kandasamy Murugesh, Adrian Oblak, Kristen D. Onos, Michael Sasner, Anna K Greenwood, Kara H Woo, Stacey J Sukoff Rizzo, Paul R Territo

Faculty Research 2023

We propose an unbiased methodology to rank compounds for advancement into comprehensive preclinical testing for Alzheimer's disease (AD). Translation of compounds to the clinic in AD has been hampered by poor predictive validity of models, compounds with limited pharmaceutical properties, and studies that lack rigor. To overcome this, MODEL-AD's Preclinical Testing Core developed a standardized pipeline for assessing efficacy in AD mouse models. We hypothesize that rank-ordering compounds based upon pharmacokinetic, efficacy, and toxicity properties in preclinical models will enhance successful translation to the clinic. Previously compound selection was based solely on physiochemical properties, with arbitrary cutoff limits, making ranking …

Disrupting Actin Filaments Enhances Glucose-Stimulated Insulin Secretion Independent Of The Cortical Actin Cytoskeleton, Alexander J Polino, Xue Wen Ng, Rebecca Rooks, David W Piston

2020-Current year OA Pubs

Just under the plasma membrane of most animal cells lies a dense meshwork of actin filaments called the cortical cytoskeleton. In insulin-secreting pancreatic β cells, a long-standing model posits that the cortical actin layer primarily acts to restrict access of insulin granules to the plasma membrane. Here we test this model and find that stimulating β cells with pro-secretory stimuli (glucose and/or KCl) has little impact on the cortical actin layer. Chemical perturbations of actin polymerization, by either disrupting or enhancing filamentation, dramatically enhance glucose-stimulated insulin secretion. Using scanning electron microscopy, we directly visualize the cortical cytoskeleton, allowing us to …

Dominant Negative Variants In Kif5b Cause Osteogenesis Imperfecta Via Down Regulation Of Mtor Signaling, Ronit Marom, Anika Lindsey, Jacob Lesinski, Michael L. Nonet, Jian Chen, Dustin Baldridge, Gary A. Silverman, Stephen C. Pak, Et Al.

2020-Current year OA Pubs

BACKGROUND: Kinesin motor proteins transport intracellular cargo, including mRNA, proteins, and organelles. Pathogenic variants in kinesin-related genes have been implicated in neurodevelopmental disorders and skeletal dysplasias. We identified de novo, heterozygous variants in KIF5B, encoding a kinesin-1 subunit, in four individuals with osteogenesis imperfecta. The variants cluster within the highly conserved kinesin motor domain and are predicted to interfere with nucleotide binding, although the mechanistic consequences on cell signaling and function are unknown.

METHODS: To understand the in vivo genetic mechanism of KIF5B variants, we modeled the p.Thr87Ile variant that was found in two patients in the C. elegans ortholog, …

Small Molecule Screen Identifies Pyrimethamine As An Inhibitor Of Nrf2-Driven Esophageal Hyperplasia, Chorlada Paiboonrungruang, Brittany Bowman, Julius Chembo, M Ben Major, Et Al.

2020-Current year OA Pubs

OBJECTIVE: NRF2 is a master transcription factor that regulates the stress response. NRF2 is frequently mutated and activated in human esophageal squamous cell carcinoma (ESCC), which drives resistance to chemotherapy and radiation therapy. Therefore, a great need exists for NRF2 inhibitors for targeted therapy of NRF2

DESIGN: We performed high-throughput screening of two compound libraries from which hit compounds were further validated in human ESCC cells and a genetically modified mouse model. The mechanism of action of one compound was explored by biochemical assays.

RESULTS: Using high-throughput screening of two small molecule compound libraries, we identified 11 hit compounds as …

Cux1-Related Neurodevelopmental Disorder: Deep Insights Into Phenotype-Genotype Spectrum And Underlying Pathology, Henry Oppermann, Christina A Gurnett, Et Al.

2020-Current year OA Pubs

Heterozygous, pathogenic CUX1 variants are associated with global developmental delay or intellectual disability. This study delineates the clinical presentation in an extended cohort and investigates the molecular mechanism underlying the disorder in a Cux1

A Human Mitofusin 2 Mutation Can Cause Mitophagic Cardiomyopathy, Antonietta Franco, Jiajia Li, Daniel P Kelly, Ray E Hershberger, Ali J Marian, Renate M Lewis, Moshi Song, Xiawei Dang, Alina D Schmidt, Mary E Mathyer, John R Edwards, Cristina De Guzman Strong, Gerald W Dorn

Faculty, Staff and Student Publications

Cardiac muscle has the highest mitochondrial density of any human tissue, but mitochondrial dysfunction is not a recognized cause of isolated cardiomyopathy. Here, we determined that the rare mitofusin (MFN) 2 R400Q mutation is 15-20× over-represented in clinical cardiomyopathy, whereas this specific mutation is not reported as a cause of MFN2 mutant-induced peripheral neuropathy, Charcot-Marie-Tooth disease type 2A (CMT2A). Accordingly, we interrogated the enzymatic, biophysical, and functional characteristics of MFN2 Q400 versus wild-type and CMT2A-causing MFN2 mutants. All MFN2 mutants had impaired mitochondrial fusion, the canonical MFN2 function. Compared to MFN2 T105M that lacked catalytic GTPase activity and exhibited normal …

Alterations In Salivary Biochemical Composition And Redox State Disruption Induced By The Anticonvulsant Valproic Acid In Male Rat Salivary Glands, Rayara Nogueira De Freitas, Lucas Guilherme Leite Da Silva, Gabriela Alice Fiais, Douglas Sandrac De Biagi Ferreira, Allice Santos Cruz Veras, Giovana Rampazzo Teixeira, Sandra Helena Penha Oliveira, Rita Cássia Menegati Dornelles, Ana Cláudia De Melo Stevanato Nakamune, Walid D Fakhouri, Antonio Hernandes Chaves-Neto

Faculty, Staff and Student Publications

Objective: To investigate the effects of the anticonvulsant valproic acid (VPA) on salivary glands in male rat using biochemical, functional, histomorphometric, and redox state parameters.

Materials and methods: Twenty-four male Wistar rats were randomly distributed into three groups (n = 8 per group): Control (0.9% saline solution), VPA100 (100 mg/kg), and VPA400 (400 mg/kg). After 21 consecutive days of treatment with by intragastric gavage. Pilocarpine-induced saliva was collected to determine salivary flow rate, pH, buffering capacity, and biochemical composition. Analyses of histomorphometric parameters and redox balance markers were performed on the parotid and submandibular glands.

Results: Salivary flow rate, pH, …

Experimentally Induced Active And Quiet Sleep Engage Non-Overlapping Transcriptional Programs In Drosophila, Niki Anthoney, Lucy Tainton-Heap, Hang Luong, Eleni Notaras, Amber B Kewin, Qiongyi Zhao, Trent Perry, Philip Batterham, Paul J Shaw, Bruno Van Swinderen

2020-Current year OA Pubs

Sleep in mammals can be broadly classified into two different physiological categories: rapid eye movement (REM) sleep and slow-wave sleep (SWS), and accordingly REM and SWS are thought to achieve a different set of functions. The fruit fly

Long Non-Coding Rna Snhg8 Drives Stress Granule Formation In Tauopathies, Reshma Bhagat, Miguel A Minaya, Arun Renganathan, Muneshwar Mehra, Jacob Marsh, Rita Martinez, Abdallah M Eteleeb, Alissa L Nana, Salvatore Spina, William W Seeley, Lea T Grinberg, Celeste M Karch

2020-Current year OA Pubs

Tauopathies are a heterogenous group of neurodegenerative disorders characterized by tau aggregation in the brain. In a subset of tauopathies, rare mutations in the MAPT gene, which encodes the tau protein, are sufficient to cause disease; however, the events downstream of MAPT mutations are poorly understood. Here, we investigate the role of long non-coding RNAs (lncRNAs), transcripts >200 nucleotides with low/no coding potential that regulate transcription and translation, and their role in tauopathy. Using stem cell derived neurons from patients carrying a MAPT p.P301L, IVS10 + 16, or p.R406W mutation and CRISPR-corrected isogenic controls, we identified transcriptomic changes that occur …

A Human Mitofusin 2 Mutation Can Cause Mitophagic Cardiomyopathy, Antonietta Franco, Jiajia Li, Daniel P Kelly, Ray E Hershberger, Ali J Marian, Renate M Lewis, Moshi Song, Xiawei Dang, Alina D Schmidt, Mary E Mathyer, John R Edwards, Cristina De Guzman Strong, Gerald W Dorn

2020-Current year OA Pubs

Cardiac muscle has the highest mitochondrial density of any human tissue, but mitochondrial dysfunction is not a recognized cause of isolated cardiomyopathy. Here, we determined that the rare mitofusin (MFN) 2 R400Q mutation is 15-20× over-represented in clinical cardiomyopathy, whereas this specific mutation is not reported as a cause of MFN2 mutant-induced peripheral neuropathy, Charcot-Marie-Tooth disease type 2A (CMT2A). Accordingly, we interrogated the enzymatic, biophysical, and functional characteristics of MFN2 Q400 versus wild-type and CMT2A-causing MFN2 mutants. All MFN2 mutants had impaired mitochondrial fusion, the canonical MFN2 function. Compared to MFN2 T105M that lacked catalytic GTPase activity and exhibited normal …

Iron Overload Induces Cerebral Endothelial Senescence In Aged Mice And In Primary Culture In A Sex-Dependent Manner, Brian Noh, Maria Pilar Blasco-Conesa, Syed Mushfiqur Rahman, Sheelu Monga, Rodney Ritzel, Gary Guzman, Yun-Ju Lai, Bhanu Priya Ganesh, Akihiko Urayama, Louise D Mccullough, Jose Felix Moruno-Manchon

Faculty, Staff and Student Publications

Iron imbalance in the brain negatively affects brain function. With aging, iron levels increase in the brain and contribute to brain damage and neurological disorders. Changes in the cerebral vasculature with aging may enhance iron entry into the brain parenchyma, leading to iron overload and its deleterious consequences. Endothelial senescence has emerged as an important contributor to age-related changes in the cerebral vasculature. Evidence indicates that iron overload may induce senescence in cultured cell lines. Importantly, cells derived from female human and mice generally show enhanced senescence-associated phenotype, compared with males. Thus, we hypothesize that cerebral endothelial cells (CEC) derived …

Animal Models In Systemic Sclerosis: An Update, Xiongjie Bi, Tingting Mills, Minghua Wu

Faculty, Staff and Student Publications

Purpose of review: Systemic sclerosis (SSc) is a multisystem autoimmune connective tissue disease characterized by early inflammation followed by excessive fibrosis in the skin and internal organs. Enhancing our comprehension of SSc pathogenesis is essential to develop effective therapeutic strategies. Animal models that mimic one or more aspects of SSc have been proven to be a valuable resource for investigating disease mechanisms. This review aims to provide an updated overview of the existing SSc animal models and the potentially relevant pathways to SSc pathogenesis.

Recent findings: This review focuses on the most recently generated and investigated animal models, which delve …

Immune Cell Identity Behind The Ktrans Mapping Of Mouse Glioblastoma, Yanrong Zhang, Olivier Keunen, Anna Golebiewska, Marco Gerosa, Jing Wang, Sara Natasha Ghobadi, Ai Huang, Qingyi Hou, Frezghi G Habte, Ningrui Li, Gerry Grant, Ramasamy Paulmurugan, Kevin S Lee, Max Wintermark

Faculty, Staff and Student Publications

Dynamic contrast-enhanced MR imaging (DCE-MRI) can assess the integrity of the blood brain barrier (BBB) and has been used in GBM patients to determine glioma grade, predict prognosis, evaluate treatment response, and differentiate treatment-induced effect from recurrence. The volume transfer constant Ktrans is the most frequently used metric in tumor assessment. Based on previous studies that a higher WHO grade of brain tumor was associated with greater impairments of immunity and and that Ktrans value was associated with the pathological grading, the relationship between differential composition of immune cells in GBM tissue and dynamic changes in Ktrans mapping was anticipated …

Circulating Micrornas And Cytokines As Prognostic Biomarkers For Doxorubicin-Induced Cardiac Injury And For Evaluating The Effectiveness Of An Exercise Intervention, Prince Jeyabal, Anchit Bhagat, Fei Wang, Michael Roth, J Andrew Livingston, Susan C Gilchrist, Jose Banchs, Michelle A T Hildebrandt, Joya Chandra, Anita Deswal, Efstratios Koutroumpakis, Jian Wang, Najat C Daw, Theresa A Honey, Eugenie S Kleinerman

Faculty, Staff and Student Publications

Purpose: To define a set of biomarkers that can be used to identify patients at high risk of developing late doxorubicin (DOX)-induced cardiac morbidity with the goal of focused monitoring and early interventions.

Experimental design: Mice received phosphate buffered saline or DOX 2.5 mg/kg 2x/week for 2 weeks. Blood samples were obtained before and after therapy for quantification of miRNAs (6 and 24 hours), cytokines (24 hours), and troponin (24 hours, 4 and 6 weeks). Cardiac function was evaluated using echocardiography before and 24 hours after therapy. To assess the effectiveness of exercise intervention in preventing DOX-induced cardiotoxicity blood samples …

The Androgen Receptor Does Not Directly Regulate The Transcription Of Dna Damage Response Genes, Joshua D Samuels, Katelyn A Moore, Hannah E Ennerfelt, Alexis M Johnson, Adeline E Walsh, Richard J Price, John R Lukens

Faculty, Staff and Student Publications

INTRODUCTION: Mutations in INPP5D, which encodes for the SH2-domain-containing inositol phosphatase SHIP-1, have recently been linked to an increased risk of developing late-onset Alzheimer's disease. While INPP5D expression is almost exclusively restricted to microglia in the brain, little is known regarding how SHIP-1 affects neurobiology or neurodegenerative disease pathogenesis.

METHODS: We generated and investigated 5xFAD Inpp5d

RESULTS: SHIP-1 deletion in microglia led to substantially enhanced recruitment of microglia to Aβ plaques, altered microglial gene expression, and marked improvements in neuronal health. Further, SHIP-1 loss enhanced microglial plaque containment and Aβ engulfment when compared to microglia from Cre-negative 5xFAD Inpp5d

DISCUSSION: …

Cell-Autonomous Effects Of Apoe4 In Restricting Microglial Response In Brain Homeostasis And Alzheimer’S Disease, Chia-Chen Liu, Na Wang, Yuanxin Chen, Yasuteru Inoue, Francis Shue, Yingxue Ren, Minghui Wang, Wenhui Qiao, Tadafumi C Ikezu, Zonghua Li, Jing Zhao, Yuka Martens, Sydney V Doss, Cassandra L Rosenberg, Suren Jeevaratnam, Lin Jia, Ana-Caroline Raulin, Fangfang Qi, Yiyang Zhu, Alla Alnobani, Joshua Knight, Yixing Chen, Cynthia Linares, Aishe Kurti, John D Fryer, Bin Zhang, Long-Jun Wu, Betty Y S Kim, Guojun Bu

Faculty, Staff and Student Publications

Microglial involvement in Alzheimer's disease (AD) pathology has emerged as a risk-determining pathogenic event. While apolipoprotein E (APOE) is known to modify AD risk, it remains unclear how microglial apoE impacts brain cognition and AD pathology. Here, using conditional mouse models expressing apoE isoforms in microglia and central nervous system-associated macrophages (CAMs), we demonstrate a cell-autonomous effect of apoE3-mediated microglial activation and function, which are negated by apoE4. Expression of apoE3 in microglia/CAMs improves cognitive function, increases microglia surrounding amyloid plaque and reduces amyloid pathology and associated toxicity, whereas apoE4 expression either compromises or has no effects on these outcomes …

Interplay Of Hypoxia-Inducible Factors And Oxygen Therapy In Cardiovascular Medicine, Yafen Liang, Wei Ruan, Yandong Jiang, Richard Smalling, Xiaoyi Yuan, Holger K Eltzschig

Faculty, Staff and Student Publications

Mammals have evolved to adapt to differences in oxygen availability. Although systemic oxygen homeostasis relies on respiratory and circulatory responses, cellular adaptation to hypoxia involves the transcription factor hypoxia-inducible factor (HIF). Given that many cardiovascular diseases involve some degree of systemic or local tissue hypoxia, oxygen therapy has been used liberally over many decades for the treatment of cardiovascular disorders. However, preclinical research has revealed the detrimental effects of excessive use of oxygen therapy, including the generation of toxic oxygen radicals or attenuation of endogenous protection by HIFs. In addition, investigators in clinical trials conducted in the past decade have …

Improved Humoral Immunity And Protection Against Influenza Virus Infection With A 3d Porous Biomaterial Vaccine, Hiromi Miwa, Olivia Q Antao, Kindra M Kelly-Scumpia, Sevana Baghdasarian, Daniel P Mayer, Lily Shang, Gina M Sanchez, Maani M Archang, Philip O Scumpia, Jason S Weinstein, Dino Di Carlo

Faculty, Staff and Student Publications

New vaccine platforms that activate humoral immunity and generate neutralizing antibodies are required to combat emerging pathogens, including influenza virus. A slurry of antigen-loaded hydrogel microparticles that anneal to form a porous scaffold with high surface area for antigen uptake by infiltrating immune cells as the biomaterial degrades is demonstrated to enhance humoral immunity. Antigen-loaded-microgels elicited a robust cellular humoral immune response, with increased CD4

Cardiac Muscle-Restricted Partial Loss Of Nos1ap Expression Has Limited But Significant Impact On Electrocardiographic Features, Alexa Smith, Dallas Auer, Morgan Johnson, Ernesto Sanchez, Holly Ross, Christopher Ward, Aravinda Chakravarti, Ashish Kapoor

Faculty, Staff and Student Publications

Genome-wide association studies have identified sequence polymorphisms in a functional enhancer of the NOS1AP gene as the most common genetic regulator of QT interval and human cardiac NOS1AP gene expression in the general population. Functional studies based on in vitro overexpression in murine cardiomyocytes and ex vivo knockdown in zebrafish embryonic hearts, by us and others, have also demonstrated that NOS1AP expression levels can alter cellular electrophysiology. Here, to explore the role of NOS1AP in cardiac electrophysiology at an organismal level, we generated and characterized constitutive and heart muscle-restricted Nos1ap knockout mice to assess whether NOS1AP disruption alters the QT …

P2y2 Purinergic Receptor Gene Deletion Protects Mice From Bacterial Endotoxin And Sepsis-Associated Liver Injury And Mortality, Athis R Arunachalam, Sanju S Samuel, Arunmani Mani, Janielle P Maynard, Kelsey M Stayer, Eric Dybbro, Subapradha Narayanan, Aalekhya Biswas, Saliha Pathan, Krishnakant Soni, Abu Hena Mostafa Kamal, Chandra Shekar R Ambati, Nagireddy Putluri, Moreshwar S Desai, Sundararajah Thevananther

Faculty, Staff and Students Publications

Prostate cancer (PCa) remains a leading cause of mortality among American men, with metastatic and recurrent disease posing significant therapeutic challenges due to a limited comprehension of the underlying biological processes governing disease initiation, dormancy, and progression. The conventional use of PCa cell lines has proven inadequate in elucidating the intricate molecular mechanisms driving PCa carcinogenesis, hindering the development of effective treatments. To address this gap, patient-derived primary cell cultures have been developed and play a pivotal role in unraveling the pathophysiological intricacies unique to PCa in each individual, offering valuable insights for translational research. This review explores the applications …

Targeted Inhibition Of Lncrna Malat1 Alters The Tumor Immune Microenvironment In Preclinical Syngeneic Mouse Models Of Triple-Negative Breast Cancer, Oluwatoyosi Adewunmi, Yichao Shen, Xiang H-F Zhang, Jeffrey M Rosen

Faculty, Staff and Students Publications

Long noncoding RNAs (lncRNA) play an important role in gene regulation in both normal tissues and cancer. Targeting lncRNAs is a promising therapeutic approach that has become feasible through the development of gapmer antisense oligonucleotides (ASO). Metastasis-associated lung adenocarcinoma transcript (Malat1) is an abundant lncRNA whose expression is upregulated in several cancers. Although Malat1 increases the migratory and invasive properties of tumor cells, its role in the tumor microenvironment (TME) is still not well defined. We explored the connection between Malat1 and the tumor immune microenvironment (TIME) using several immune-competent preclinical syngeneic Tp53-null triple-negative breast cancer (TNBC) mouse models that …

Dominant Negative Variants In Kif5b Cause Osteogenesis Imperfecta Via Down Regulation Of Mtor Signaling, Ronit Marom, Bo Zhang, Megan E Washington, I-Wen Song, Lindsay C Burrage, Vittoria C Rossi, Ava S Berrier, Anika Lindsey, Jacob Lesinski, Michael L Nonet, Jian Chen, Dustin Baldridge, Gary A Silverman, V Reid Sutton, Jill A Rosenfeld, Alyssa A Tran, M John Hicks, David R Murdock, Hongzheng Dai, Maryann Weis, Shalini N Jhangiani, Donna M Muzny, Richard A Gibbs, Richard Caswell, Carrie Pottinger, Deirdre Cilliers, Karen Stals, Undiagnosed Diseases Network, David Eyre, Deborah Krakow, Tim Schedl, Stephen C Pak, Brendan H Lee

Faculty, Staff and Students Publications

BACKGROUND: Kinesin motor proteins transport intracellular cargo, including mRNA, proteins, and organelles. Pathogenic variants in kinesin-related genes have been implicated in neurodevelopmental disorders and skeletal dysplasias. We identified de novo, heterozygous variants in KIF5B, encoding a kinesin-1 subunit, in four individuals with osteogenesis imperfecta. The variants cluster within the highly conserved kinesin motor domain and are predicted to interfere with nucleotide binding, although the mechanistic consequences on cell signaling and function are unknown.

METHODS: To understand the in vivo genetic mechanism of KIF5B variants, we modeled the p.Thr87Ile variant that was found in two patients in the C. elegans ortholog, …

Aso Silencing Of A Glycosyltransferase, Poglut1, Improves The Liver Phenotypes In Mouse Models Of Alagille Syndrome, Nima Niknejad, Duncan Fox, Jennifer L Burwinkel, Neda Zarrin-Khameh, Soomin Cho, Armand Soriano, Ashley E Cast, Mario F Lopez, Kari A Huppert, Frank Rigo, Stacey S Huppert, Paymaan Jafar-Nejad, Hamed Jafar-Nejad

Faculty, Staff and Students Publications

BACKGROUND AND AIMS: Paucity of intrahepatic bile ducts (BDs) is caused by various etiologies and often leads to cholestatic liver disease. For example, in patients with Alagille syndrome (ALGS), which is a genetic disease primarily caused by mutations in jagged 1 ( JAG1) , BD paucity often results in severe cholestasis and liver damage. However, no mechanism-based therapy exists to restore the biliary system in ALGS or other diseases associated with BD paucity. Based on previous genetic observations, we investigated whether postnatal knockdown of the glycosyltransferase gene protein O -glucosyltransferase 1 ( Poglut1) can improve the ALGS liver phenotypes in …

The Impact Of Vaccine-Linked Chemotherapy On Liver Health In A Mouse Model Of Chronic Trypanosoma Cruzi Infection, Duc Minh Nguyen, Cristina Poveda, Jeroen Pollet, Fabian Gusovsky, Maria Elena Bottazzi, Peter J Hotez, Kathryn Marie Jones

Faculty, Staff and Students Publications

BACKGROUND: Chagas disease, chronic infection with Trypanosoma cruzi, mainly manifests as cardiac disease. However, the liver is important for both controlling parasite burdens and metabolizing drugs. Notably, high doses of anti-parasitic drug benznidazole (BNZ) causes liver damage. We previously showed that combining low dose BNZ with a prototype therapeutic vaccine is a dose sparing strategy that effectively reduced T. cruzi induced cardiac damage. However, the impact of this treatment on liver health is unknown. Therefore, we evaluated several markers of liver health after treatment with low dose BNZ plus the vaccine therapy in comparison to a curative dose of BNZ. …

Increasing Glutathione Levels By A Novel Posttranslational Mechanism Inhibits Neuronal Hyperexcitability, Ashwini Sri Hari, Rajeswari Banerji, Li-Ping Liang, Ruth E Fulton, Christopher Quoc Huynh, Timothy Fabisiak, Pallavi Bhuyan Mcelroy, James R Roede, Manisha Patel

Faculty, Staff and Students Publications

Glutathione (GSH) depletion, and impaired redox homeostasis have been observed in experimental animal models and patients with epilepsy. Pleiotropic strategies that elevate GSH levels via transcriptional regulation have been shown to significantly decrease oxidative stress and seizure frequency, increase seizure threshold, and rescue certain cognitive deficits. Whether elevation of GSH per se alters neuronal hyperexcitability remains unanswered. We previously showed that thiols such as dimercaprol (DMP) elevate GSH via post-translational activation of glutamate cysteine ligase (GCL), the rate limiting GSH biosynthetic enzyme. Here, we asked if elevation of cellular GSH by DMP altered neuronal hyperexcitability in-vitro and in-vivo. Treatment of …

P2y2 Purinergic Receptor Gene Deletion Protects Mice From Bacterial Endotoxin And Sepsis-Associated Liver Injury And Mortality, Athis R Arunachalam, Sanju S Samuel, Arunmani Mani, Janielle P Maynard, Kelsey M Stayer, Eric Dybbro, Subapradha Narayanan, Aalekhya Biswas, Saliha Pathan, Krishnakant Soni, Abu Hena Mostafa Kamal, Chandra Shekar R Ambati, Nagireddy Putluri, Moreshwar S Desai, Sundararajah Thevananther

Faculty, Staff and Students Publications

The liver plays a significant role in regulating a wide range of metabolic, homeostatic, and host-defense functions. However, the impact of liver injury on the host's ability to control bacteremia and morbidity in sepsis is not well understood. Leukocyte recruitment and activation lead to cytokine and chemokine release, which, in turn, trigger hepatocellular injury and elevate nucleotide levels in the extracellular milieu. P2Y2 purinergic receptors, G protein-coupled and activated by extracellular ATP/UTP, are expressed at the cell surface of hepatocytes and nonparenchymal cells. We sought to determine whether P2Y2 purinergic receptor function is necessary for the maladaptive host response to …

Site-Specific Pathophysiology In A Neonatal Mouse Model Of Gastroparesis, Price T Edwards, Krishnakant G Soni, Margaret E Conner, Stephanie W Fowler, Jaime P P Foong, Rhian Stavely, Lily S Cheng, Geoffrey A Preidis

Faculty, Staff and Students Publications

BACKGROUND: Early-life events impact maturation of the gut microbiome, enteric nervous system, and gastrointestinal motility. We examined three regions of gastric tissue to determine how maternal separation and gut microbes influence the structure and motor function of specific regions of the neonatal mouse stomach.

METHODS: Germ-free and conventionally housed C57BL/6J mouse pups underwent timed maternal separation (TmSep) or nursed uninterrupted (controls) until 14 days of life. We assessed gastric emptying by quantifying the progression of gavaged fluorescein isothiocyanate (FITC)-dextran. With isolated rings of forestomach, corpus, and antrum, we measured tone and contractility by force transduction, gastric wall thickness by light …

Therapeutic Implications Of Impaired Nuclear Receptor Function And Dysregulated Metabolism In Wilson’S Disease, Clavia Ruth Wooton-Kee

Faculty, Staff and Students Publications

Copper is an essential trace element that is required for the activity of many enzymes and cellular processes, including energy homeostasis and neurotransmitter biosynthesis; however, excess copper accumulation results in significant cellular toxicity. The liver is the major organ for maintaining copper homeostasis. Inactivating mutations of the copper-transporting P-type ATPase, ATP7B, result in Wilson’s disease, an autosomal recessive disorder that requires life-long medicinal therapy or liver transplantation. Current treatment protocols are limited to either sequestration of copper via chelation or reduction of copper absorption in the gut (zinc therapy). The goal of these strategies is to reduce free copper, redox …