Medical Specialties Commons^™

Tfeb Regulates Murine Liver Cell Fate During Development And Regeneration, Nunzia Pastore, Tuong Huynh, Niculin J Herz, Alessia Calcagni', Tiemo J Klisch, Lorenzo Brunetti, Kangho Ho Kim, Marco De Giorgi, Ayrea Hurley, Annamaria Carissimo, Margherita Mutarelli, Niya Aleksieva, Luca D'Orsi, William R Lagor, David D Moore, Carmine Settembre, Milton J Finegold, Stuart J Forbes, Andrea Ballabio

Faculty, Staff and Students Publications

It is well established that pluripotent stem cells in fetal and postnatal liver (LPCs) can differentiate into both hepatocytes and cholangiocytes. However, the signaling pathways implicated in the differentiation of LPCs are still incompletely understood. Transcription Factor EB (TFEB), a master regulator of lysosomal biogenesis and autophagy, is known to be involved in osteoblast and myeloid differentiation, but its role in lineage commitment in the liver has not been investigated. Here we show that during development and upon regeneration TFEB drives the differentiation status of murine LPCs into the progenitor/cholangiocyte lineage while inhibiting hepatocyte differentiation. Genetic interaction studies show that …

Nk Cell-Derived Gm-Csf Potentiates Inflammatory Arthritis And Is Negatively Regulated By Cis, Cynthia Louis, Fernando Souza-Fonseca-Guimaraes, Yuyan Yang, Damian D'Silva, Tobias Kratina, Laura Dagley, Soroor Hediyeh-Zadeh, Jai Rautela, Seth Lucian Masters, Melissa J Davis, Jeffrey J Babon, Bogoljub Ciric, Eric Vivier, Warren S Alexander, Nicholas D Huntington, Ian P Wicks

Department of Neurology Faculty Papers

Despite increasing recognition of the importance of GM-CSF in autoimmune disease, it remains unclear how GM-CSF is regulated at sites of tissue inflammation. Using GM-CSF fate reporter mice, we show that synovial NK cells produce GM-CSF in autoantibody-mediated inflammatory arthritis. Synovial NK cells promote a neutrophilic inflammatory cell infiltrate, and persistent arthritis, via GM-CSF production, as deletion of NK cells, or specific ablation of GM-CSF production in NK cells, abrogated disease. Synovial NK cell production of GM-CSF is IL-18–dependent. Furthermore, we show that cytokine-inducible SH2-containing protein (CIS) is crucial in limiting GM-CSF signaling not only during inflammatory arthritis but also …

The Effects Of Total Body Proton Irradiation On Mouse Myometrium, Lillith Bulawa

Undergraduate Honors Theses

The boundaries of human space exploration continue to expand with new technology and discoveries making it even more important to investigate the effects of space on biological systems. Although humans have explored space in small increments, reproductive studies must be conducted to determine if stable short- or long-term residences for humans can exist in space. This study explored the effects of whole-body proton radiation on uterine smooth muscle known as the myometrium. Two types of mice utilized in this study were C57BL/6 and B6.129S6Cybbtm1Din/J NOX2 knockout mice. C57BL/6 mice are standard laboratory mice that were used to represent the wildtype …

Ubiquitination Of The Dna-Damage Checkpoint Kinase Chk1 By Traf4 Is Required For Chk1 Activation, Xinfang Yu, Wei Li, Haidan Liu, Qipan Deng, Xu Wang, Hui Hu, Zijun Y Xu-Monette, Wei Xiong, Zhongxin Lu, Ken H Young, Wei Wang, Yong Li

Faculty, Staff and Students Publications

BACKGROUND: Aberrant activation of DNA damage response (DDR) is a major cause of chemoresistance in colorectal cancer (CRC). CHK1 is upregulated in CRC and contributes to therapeutic resistance. We investigated the upstream signaling pathways governing CHK1 activation in CRC.

METHODS: We identified CHK1-binding proteins by mass spectrometry analysis. We analyzed the biologic consequences of knockout or overexpression of TRAF4 using immunoblotting, immunoprecipitation, and immunofluorescence. CHK1 and TRAF4 ubiquitination was studied in vitro and in vivo. We tested the functions of TRAF4 in CHK1 phosphorylation and CRC chemoresistance by measuring cell viability and proliferation, anchorage-dependent and -independent cell growth, and mouse …

Metabolic-Sensing Of The Skeletal Muscle Clock Coordinates Fuel Oxidation, Hongshan Yin, Weini Li, Somik Chatterjee, Xuekai Xiong, Pradip Saha, Vijay Yechoor, Ke Ma

Faculty, Staff and Students Publications

Circadian clock confers temporal control in metabolism, with its disruption leading to the development of insulin resistance. Metabolic substrate utilization in skeletal muscle is coordinated with diurnal nutrient cycles. However, whether the molecular clock is involved in this coordination is largely unknown. Using a myocyte-selective genetic ablation mouse model of the essential clock activator Bmal1, here we identify muscle-intrinsic clock as a sensor of feeding cues to orchestrate skeletal muscle oxidation required for global nutrient flux. Bmal1 in skeletal muscle responds robustly to feeding in vivo and insulin induces its expression. Muscle Bmal1 deficiency impaired the transcriptional control of glucose …

Estrogen Receptor-Α Expressing Neurons In The Ventrolateral Vmh Regulate Glucose Balance, Yanlin He, Pingwen Xu, Chunmei Wang, Yan Xia, Meng Yu, Yongjie Yang, Kaifan Yu, Xing Cai, Na Qu, Kenji Saito, Julia Wang, Ilirjana Hyseni, Matthew Robertson, Badrajee Piyarathna, Min Gao, Sohaib A Khan, Feng Liu, Rui Chen, Cristian Coarfa, Zhongming Zhao, Qingchun Tong, Zheng Sun, Yong Xu

Children’s Nutrition Research Center Staff Publications

Brain glucose-sensing neurons detect glucose fluctuations and prevent severe hypoglycemia, but mechanisms mediating functions of these glucose-sensing neurons are unclear. Here we report that estrogen receptor-α (ERα)-expressing neurons in the ventrolateral subdivision of the ventromedial hypothalamic nucleus (vlVMH) can sense glucose fluctuations, being glucose-inhibited neurons (GI-ERαvlVMH) or glucose-excited neurons (GE-ERαvlVMH). Hypoglycemia activates GI-ERαvlVMH neurons via the anoctamin 4 channel, and inhibits GE-ERαvlVMH neurons through opening the ATP-sensitive potassium channel. Further, we show that GI-ERαvlVMH neurons preferentially project to the medioposterior arcuate nucleus of the hypothalamus (mpARH) and GE-ERαvlVMH neurons preferentially project to the dorsal Raphe nuclei (DRN). Activation of ERαvlVMH …

Bispecific Human Il2-Ccr4 Immunotoxin Targets Human Cutaneous T-Cell Lymphoma, Haoyu Wang, Zhaohui Wang, Huiping Zhang, Zeng Qi, Ariel C Johnson, David Mathes, Elizabeth A Pomfret, Erin Rubin, Christene A Huang, Zhirui Wang

Faculty, Staff and Student Publications

The majority of clinically diagnosed cutaneous T‐cell lymphomas (CTCL) highly express the cell‐surface markers CC chemokine receptor 4 (CCR4) and/or CD25. Recently, we have developed diphtheria toxin‐based recombinant Ontak®‐like human IL2 fusion toxin (IL2 fusion toxin) and anti‐human CCR4 immunotoxin (CCR4 IT). In this study, we first compared the efficacy of the CCR4 IT vs IL2 fusion toxin for targeting human CD25+CCR4+ CTCL. We demonstrated that CCR4 IT was more effective than IL2 fusion toxin. We further constructed an IL2‐CCR4 bispecific IT. The bispecific IT was significantly more effective than either IL2 fusion toxin or CCR4 IT alone. The bispecific …

Dietary Fat And Sugar Differentially Affect Β-Adrenergic Stimulation Of Cardiac Erk And Akt Pathways In C57bl/6 Male Mice Subjected To High-Calorie Feeding, Sadia Ashraf, Gizem Yilmaz, Xu Chen, Romain Harmancey

Faculty, Staff and Student Publications

BACKGROUND: High dietary fat and sugar promote cardiac hypertrophy independently from an increase in blood pressure. The respective contribution that each macronutrient exerts on cardiac growth signaling pathways remains unclear.

OBJECTIVE: The goal of this study was to investigate the mechanisms by which high amounts of dietary fat and sugar affect cardiac growth regulatory pathways.

METHODS: Male C57BL/6 mice (9 wk old; n = 20/group) were fed a standard rodent diet (STD; kcal% protein-fat-carbohydrate, 29-17-54), a high-fat diet (HFD; 20-60-20), a high-fat and high-sugar Western diet (WD; 20-45-35), a high-sugar diet with mixed carbohydrates (HCD; 20-10-70), or a high-sucrose diet …

Dietary Fat And Sugar Differentially Affect Β-Adrenergic Stimulation Of Cardiac Erk And Akt Pathways In C57bl/6 Male Mice Subjected To High-Calorie Feeding, Sadia Ashraf, Gizem Yilmaz, Xu Chen, Romain Harmancey

Faculty, Staff and Student Publications

BACKGROUND: High dietary fat and sugar promote cardiac hypertrophy independently from an increase in blood pressure. The respective contribution that each macronutrient exerts on cardiac growth signaling pathways remains unclear.

OBJECTIVE: The goal of this study was to investigate the mechanisms by which high amounts of dietary fat and sugar affect cardiac growth regulatory pathways.

METHODS: Male C57BL/6 mice (9 wk old; n = 20/group) were fed a standard rodent diet (STD; kcal% protein-fat-carbohydrate, 29-17-54), a high-fat diet (HFD; 20-60-20), a high-fat and high-sugar Western diet (WD; 20-45-35), a high-sugar diet with mixed carbohydrates (HCD; 20-10-70), or a high-sucrose diet …

Modulating The Rate Of Fibrin Formation And Clot Structure Attenuates Microvascular Thrombosis In Systemic Inflammation, Christian Valladolid, Marina Martinez-Vargas, Nitin Sekhar, Fong Lam, Cameron Brown, Timothy Palzkill, Alexander Tischer, Mathew Auton, K Vinod Vijayan, Rolando E Rumbaut, Trung C Nguyen, Miguel A Cruz

Faculty, Staff and Students Publications

Systemic inflammation can lead to coagulopathy and disseminated intravascular coagulation (DIC). In prior studies, the recombinant A2 domain of human von Willebrand factor (VWF; A2 protein) attenuated DIC and decreased mortality in lipopolysaccharide (LPS)-treated mice. Here, we performed studies to dissect the mechanism by which the A2 protein moderates DIC. We used confocal microscopy to analyze the fibrin clot structure in plasma from healthy humans and endotoxemic mice, turbidity assays to examine fibrin polymerization, and a murine model for LPS-induced DIC and introduced a loss-of-function mutation into the A2 protein for fibrin. The mutation of the residue E1567 located in …

Integrating Mouse And Human Genetic Data To Move Beyond Gwas And Identify Causal Genes In Cholesterol Metabolism, Zhonggang Li, James A Votava, Gregory J M Zajac, Jenny N Nguyen, Fernanda B Leyva Jaimes, Sophia M Ly, Jacqueline A Brinkman, Marco De Giorgi, Sushma Kaul, Cara L Green, Samantha L St Clair, Sabrina L Belisle, Julia M Rios, David W Nelson, Mary G Sorci-Thomas, William R Lagor, Dudley W Lamming, Chi-Liang Eric Yen, Brian W Parks

Faculty, Staff and Students Publications

Identifying the causal gene(s) that connects genetic variation to a phenotype is a challenging problem in genome-wide association studies (GWASs). Here, we develop a systematic approach that integrates mouse liver co-expression networks with human lipid GWAS data to identify regulators of cholesterol and lipid metabolism. Through our approach, we identified 48 genes showing replication in mice and associated with plasma lipid traits in humans and six genes on the X chromosome. Among these 54 genes, 25 have no previously identified role in lipid metabolism. Based on functional studies and integration with additional human lipid GWAS datasets, we pinpoint Sestrin1 as …

De Novo Frameshift Variants In The Neuronal Splicing Factor Nova2 Result In A Common C-Terminal Extension And Cause A Severe Form Of Neurodevelopmental Disorder, Francesca Mattioli, Gaelle Hayot, Nathalie Drouot, Bertrand Isidor, Jérémie Courraud, Maria-Victoria Hinckelmann, Frederic Tran Mau-Them, Chantal Sellier, Alica Goldman, Aida Telegrafi, Alicia Boughton, Candace Gamble, Sebastien Moutton, Angélique Quartier, Nolwenn Jean, Paul Van Ness, Sarah Grotto, Sophie Nambot, Ganka Douglas, Yue Cindy Si, Jamel Chelly, Zohra Shad, Elisabeth Kaplan, Richard Dineen, Christelle Golzio, Nicolas Charlet-Berguerand, Jean-Louis Mandel, Amélie Piton

Faculty, Staff and Students Publications

The neuro-oncological ventral antigen 2 (NOVA2) protein is a major factor regulating neuron-specific alternative splicing (AS), previously associated with an acquired neurologic condition, the paraneoplastic opsoclonus-myoclonus ataxia (POMA). We report here six individuals with de novo frameshift variants in NOVA2 affected with a severe neurodevelopmental disorder characterized by intellectual disability (ID), motor and speech delay, autistic features, hypotonia, feeding difficulties, spasticity or ataxic gait, and abnormal brain MRI. The six variants lead to the same reading frame, adding a common proline rich C-terminal part instead of the last KH RNA binding domain. We detected 41 genes differentially spliced after NOVA2 …

An In Vivo Genome-Wide Crispr Screen Identifies The Rna-Binding Protein Staufen2 As A Key Regulator Of Myeloid Leukemia, Jeevisha Bajaj, Michael Hamilton, Yutaka Shima, Kendall Chambers, Kyle Spinler, Eric L Van Nostrand, Brian A Yee, Steven M Blue, Michael Chen, David Rizzeri, Charles Chuah, Vivian G Oehler, H Elizabeth Broome, Roman Sasik, James Scott-Browne, Anjana Rao, Gene W Yeo, Tannishtha Reya

Faculty, Staff and Students Publications

Aggressive myeloid leukemias such as blast crisis chronic myeloid leukemia and acute myeloid leukemia remain highly lethal. Here we report a genome-wide in vivo CRISPR screen to identify new dependencies in this disease. Among these, RNA-binding proteins (RBPs) in general, and the double-stranded RBP Staufen2 (Stau2) in particular, emerged as critical regulators of myeloid leukemia. In a newly developed knockout mouse, loss of Stau2 led to a profound decrease in leukemia growth and improved survival in mouse models of the disease. Further, Stau2 was required for growth of primary human blast crisis chronic myeloid leukemia and acute myeloid leukemia. Finally, …

Cofilin-1-Induced Actin Reorganization In Stored Platelets, Swapan K Dasgupta, Perumal Thiagarajan

Faculty, Staff and Students Publications

BACKGROUND: During platelet storage, there are extensive changes in cytoskeleton and phosphatidylserine exposure. The intrinsic mitochondrial pathway of apoptosis, activated in stored platelets, is a major mediator these changes. Cofilin-1 is an effector of actin reorganization. We examined the effect of cofilin-1 deficiency on cytoskeleton and phosphatidylserine exposure during storage and following activation of apoptosis.

METHODS AND RESULTS: We assessed actin filaments by Alexa-647-phalloidin and phosphatidylserine exposure by fluorescein isothiocyanate-lactadherin by fluorescence microscopy. In fresh platelets, actin filaments are distributed in the subcortical region, and they do not express phosphatidylserine in the outer surface. In stored platelets, there is retraction …

Neurochemical Characterization Of Brainstem Pro-Opiomelanocortin Cells, Teodora Georgescu, David Lyons, Barbora Doslikova, Ana Paula Garcia, Oliver Marston, Luke K Burke, Raffaella Chianese, Brian Y H Lam, Giles S H Yeo, Justin J Rochford, Alastair S Garfield, Lora K Heisler

Faculty, Staff and Student Publications

Genetic research has revealed pro-opiomelanocortin (POMC) to be a fundamental regulator of energy balance and body weight in mammals. Within the brain, POMC is primarily expressed in the arcuate nucleus of the hypothalamus (ARC), while a smaller population exists in the brainstem nucleus of the solitary tract (POMCNTS). We performed a neurochemical characterization of this understudied population of POMC cells using transgenic mice expressing green fluorescent protein (eGFP) under the control of a POMC promoter/enhancer (PomceGFP). Expression of endogenous Pomc mRNA in the nucleus of the solitary tract (NTS) PomceGFP cells was confirmed using fluorescence-activating cell sorting (FACS) followed by …

Nr2f1 Heterozygous Knockout Mice Recapitulate Neurological Phenotypes Of Bosch-Boonstra-Schaaf Optic Atrophy Syndrome And Show Impaired Hippocampal Synaptic Plasticity, Chun-An Chen, Wei Wang, Steen E Pedersen, Ayush Raman, Michelle L Seymour, Fernanda R Ruiz, Anping Xia, Meike E Van Der Heijden, Li Wang, Jiani Yin, Joanna Lopez, Megan E Rech, Richard A Lewis, Samuel M Wu, Zhandong Liu, Fred A Pereira, Robia G Pautler, Huda Y Zoghbi, Christian P Schaaf

Faculty, Staff and Students Publications

Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) has been identified as an autosomal-dominant disorder characterized by a complex neurological phenotype, with high prevalence of intellectual disability and optic nerve atrophy/hypoplasia. The syndrome is caused by loss-of-function mutations in NR2F1, which encodes a highly conserved nuclear receptor that serves as a transcriptional regulator. Previous investigations to understand the protein's role in neurodevelopment have mostly used mouse models with constitutive and tissue-specific homozygous knockout of Nr2f1. In order to represent the human disease more accurately, which is caused by heterozygous NR2F1 mutations, we investigated a heterozygous knockout mouse model and found that this model …

Discovery Of A Bacterial Peptide As A Modulator Of Glp-1 And Metabolic Disease, Catherine Tomaro-Duchesneau, Stephanie L Levalley, Daniel Roeth, Liang Sun, Frank T Horrigan, Markus Kalkum, Joseph M Hyser, Robert A Britton

Faculty, Staff and Students Publications

Early work in rodents highlighted the gut microbiota's importance in metabolic disease, including Type II Diabetes Mellitus (T2DM) and obesity. Glucagon-like peptide-1 (GLP-1), an incretin secreted by L-cells lining the gastrointestinal epithelium, has important functions: promoting insulin secretion, insulin sensitivity, and β-cell mass, while inhibiting gastric emptying and appetite. We set out to identify microbial strains with GLP-1 stimulatory activity as potential metabolic disease therapeutics. Over 1500 human-derived strains were isolated from healthy individuals and screened for GLP-1 modulation by incubating bacterial cell-free supernatants with NCI H716 L-cells. Approximately 45 strains capable of increasing GLP-1 were discovered. All GLP-1 positive …

Cell Type Composition And Circuit Organization Of Clonally Related Excitatory Neurons In The Juvenile Mouse Neocortex, Cathryn R Cadwell, Federico Scala, Paul G Fahey, Dmitry Kobak, Shalaka Mulherkar, Fabian H Sinz, Stelios Papadopoulos, Zheng H Tan, Per Johnsson, Leonard Hartmanis, Shuang Li, Ronald J Cotton, Kimberley F Tolias, Rickard Sandberg, Philipp Berens, Xiaolong Jiang, Andreas Savas Tolias

Faculty, Staff and Students Publications

Clones of excitatory neurons derived from a common progenitor have been proposed to serve as elementary information processing modules in the neocortex. To characterize the cell types and circuit diagram of clonally related excitatory neurons, we performed multi-cell patch clamp recordings and Patch-seq on neurons derived from Nestin-positive progenitors labeled by tamoxifen induction at embryonic day 10.5. The resulting clones are derived from two radial glia on average, span cortical layers 2–6, and are composed of a random sampling of transcriptomic cell types. We find an interaction between shared lineage and connection type: related neurons are more likely to …

Methyl-Sensing Nuclear Receptor Liver Receptor Homolog-1 Regulates Mitochondrial Function In Mouse Hepatocytes, Sungwoo Choi, Bingning Dong, Chih-Chun Janet Lin, Mi Jeong Heo, Kang Ho Kim, Zhen Sun, Martin Wagner, Nagireddy Putluri, Jae Myoung Suh, Meng C Wang, David D Moore

Faculty, Staff and Students Publications

Liver receptor homologue-1 (LRH-1; NR5A2) is a nuclear receptor that regulates metabolic homeostasis in the liver. Previous studies identified phosphatidylcholines as potential endogenous agonist ligands for LRH-1. In the liver, distinct subsets of phosphatidylcholine species are generated by two different pathways: choline addition to phosphatidic acid via the Kennedy pathway, or trimethylation of phosphatidylethanolamine via Phosphatidylethanolamine N-methyl Transferase (PEMT). Here we report that a PEMT - LRH-1 pathway specifically couples methyl metabolism and mitochondrial activities in hepatocytes. We show that the loss of Lrh-1 reduces mitochondrial number, basal respiration, beta-oxidation and ATP production in hepatocytes, and decreases expression of mitochondrial …

Insights Image For "Evidence Of Increased Hypoxia Signalling In Fetal Liver From Maternal Nutrient Restriction In Mice"., Bethany N Radford, Victor K M Han

Paediatrics Publications

No abstract provided.

Evidence Of Increased Hypoxia Signaling In Fetal Liver From Maternal Nutrient Restriction In Mice., Bethany N Radford, Victor K M Han

Paediatrics Publications

BACKGROUND: Intrauterine growth restriction (IUGR) is a pregnancy condition where fetal growth is reduced, and offspring from IUGR pregnancies are at increased risk for type II diabetes as adults. The liver is susceptible to fetal undernutrition experienced by IUGR infants and animal models of growth restriction. This study aimed to examine hepatic expression changes in a maternal nutrient restriction (MNR) mouse model of IUGR to understand fetal adaptations that influence adult metabolism.

METHODS: Liver samples of male offspring from MNR (70% of ad libitum starting at E6.5) or control pregnancies were obtained at E18.5 and differential expression was assessed by …

Impaired Meningeal Lymphatic Vessel Development Worsens Stroke Outcome, Pavel Yanev, Katherine Poinsatte, Devon Hominick, Noor Khurana, Kielen R. Zuurbier, Marcus Berndt, Erik J. Plautz, Michael T. Dellinger, Ann M. Stowe

Neurology Faculty Publications

The discovery of meningeal lymphatic vessels (LVs) has sparked interest in identifying their role in diseases of the central nervous system. Similar to peripheral LVs, meningeal LVs depend on vascular endothelial growth factor receptor-3 (VEGFR3) signaling for development. Here we characterize the effect of stroke on meningeal LVs, and the impact of meningeal lymphatic hypoplasia on post-stroke outcomes. We show that photothrombosis (PT), but not transient middle cerebral artery occlusion (tMCAo), induces meningeal lymphangiogenesis in young male C57Bl/J6 mice. We also show that Vegfr3^wt/mut mice develop significantly fewer meningeal LVs than Vegfr3^wt/wt mice. Again, meningeal lymphangiogenesis occurs in …

Short-Chain Fatty Acids Improve Poststroke Recovery Via Immunological Mechanisms, Rebecca Sadler, Julia V. Cramer, Steffanie Heindl, Sarantos Kostidis, Dene Betz, Kielen R. Zuurbier, Bernd H. Northoff, Marieke Heijink, Mark P. Goldberg, Erik J. Plautz, Stefan Roth, Rainer Malik, Martin Dichgans, Lesca M. Holdt, Corinne Benakis, Martin Giera, Ann M. Stowe, Arthur Liesz

Neurology Faculty Publications

Recovery after stroke is a multicellular process encompassing neurons, resident immune cells, and brain-invading cells. Stroke alters the gut microbiome, which in turn has considerable impact on stroke outcome. However, the mechanisms underlying gut–brain interaction and implications for long-term recovery are largely elusive. Here, we tested the hypothesis that short-chain fatty acids (SCFAs), key bioactive microbial metabolites, are the missing link along the gut–brain axis and might be able to modulate recovery after experimental stroke. SCFA supplementation in the drinking water of male mice significantly improved recovery of affected limb motor function. Using in vivo wide-field calcium imaging, we observed …

Metabolic Dysregulation In The Atp7b-/- Wilson's Disease Mouse Model, Clavia Ruth Wooton-Kee, Matthew Robertson, Ying Zhou, Bingning Dong, Zhen Sun, Kang Ho Kim, Hailan Liu, Yong Xu, Nagireddy Putluri, Pradip Saha, Cristian Coarfa, David D Moore, Alli M Nuotio-Antar

Faculty, Staff and Students Publications

Inactivating mutations in the copper transporter Atp7b result in Wilson’s disease. The Atp7b−/− mouse develops hallmarks of Wilson’s disease. The activity of several nuclear receptors decreased in Atp7b−/− mice, and nuclear receptors are critical for maintaining metabolic homeostasis. Therefore, we anticipated that Atp7b−/− mice would exhibit altered progression of diet-induced obesity, fatty liver, and insulin resistance. Following 10 wk on a chow or Western-type diet (40% kcal fat), parameters of glucose and lipid homeostasis were measured. Hepatic metabolites were measured by liquid chromatography–mass spectrometry and correlated with transcriptomic data. Atp7b−/− mice fed a chow diet presented …

Targeting The Tumor Core: Hypoxia-Responsive Nanoparticles For The Delivery Of Chemotherapy To Pancreatic Tumors, Matthew I. Confeld, Babak Mamnoon, Li Feng, Heather Jensen Smith, Priyanka Ray, James Froberg, Jiha Kim, Michael A. Hollingsworth, Mohiuddin Quadir, Yongki Choi, Sanku Mallik

Journal Articles: Eppley Institute

In pancreatic ductal adenocarcinoma (PDAC), early onset of hypoxia triggers remodeling of the extracellular matrix, epithelial-to-mesenchymal transition, increased cell survival, the formation of cancer stem cells, and drug resistance. Hypoxia in PDAC is also associated with the development of collagen-rich, fibrous extracellular stroma (desmoplasia), resulting in severely impaired drug penetration. To overcome these daunting challenges, we created polymer nanoparticles (polymersomes) that target and penetrate pancreatic tumors, reach the hypoxic niches, undergo rapid structural destabilization, and release the encapsulated drugs. In vitro studies indicated a high cellular uptake of the polymersomes and increased cytotoxicity of the drugs under hypoxia compared to …

Sirt3 Promotes Lipophagy And Chaperon-Mediated Autophagy To Protect Hepatocytes Against Lipotoxicity, Tian Zhang, Jingxin Liu, Shengnan Shen, Qiang Tong, Xiaojun Ma, Ligen Lin

Faculty, Staff and Students Publications

Lipophagy is a lysosomal lipolytic pathway that complements the actions of cytosolic neutral lipases. Chaperon-mediated autophagy (CMA) triggers lipid droplets (LDs) breakdown, to initiate lipolysis via either cytosolic lipases or macroautophagy. SIRT3, a mitochondrial NAD+-dependent deacetylase, regulates the acetylation status and activity of many substrates involving in energy metabolism. However, the role of SIRT3 in regulating lipophagy is controversial. The current study showed that SIRT3 expression was decreased and the macroautophagy flux was blocked in the primary hepatocytes from high-fat diet fed mice and P/O (palmitic acid and oleic acid mixture) treated AML12 mouse hepatocytes, compared with the corresponding controls. …

Extracellular Mitochondria Released From Traumatized Brains Induced Platelet Procoagulant Activity, Zilong Zhao, Yuan Zhou, Tristan Hilton, Fanjian Li, Cha Han, Li Liu, Hengjie Yuan, Ying Li, Xin Xu, Xiaoping Wu, Fangyi Zhang, Perumal Thiagarajan, Andrew Cap, Fu-Dong Shi, Jianning Zhang, Jing-Fei Dong

Faculty, Staff and Students Publications

Coagulopathy often develops soon after acute traumatic brain injury and its cause remains poorly understood. We have shown that injured brains release cellular microvesicles that disrupt the endothelial barrier and induce consumptive coagulopathy. Morphologically intact extracellular mitochondria accounted for 55.2% of these microvesicles, leading to the hypothesis that these extracellular mitochondria are metabolically active and serve as a source of oxidative stress that activates platelets and renders them procoagulant. In testing this hypothesis experimentally, we found that the extracellular mitochondria purified from brain trauma mice and those released from brains subjected to freeze-thaw injury remained metabolically active and produced reactive …

Ultrafast Two-Photon Imaging Of A High-Gain Voltage Indicator In Awake Behaving Mice, Vincent Villette, Mariya Chavarha, Ivan K Dimov, Jonathan Bradley, Lagnajeet Pradhan, Benjamin Mathieu, Stephen W Evans, Simon Chamberland, Dongqing Shi, Renzhi Yang, Benjamin B Kim, Annick Ayon, Abdelali Jalil, François St-Pierre, Mark J Schnitzer, Guoqiang Bi, Katalin Toth, Jun Ding, Stéphane Dieudonné, Michael Z Lin

Faculty, Staff and Students Publications

Optical interrogation of voltage in deep brain locations with cellular resolution would be immensely useful for understanding how neuronal circuits process information. Here, we report ASAP3, a genetically encoded voltage indicator with 51% fluorescence modulation by physiological voltages, submillisecond activation kinetics, and full responsivity under two-photon excitation. We also introduce an ultrafast local volume excitation (ULoVE) method for kilohertz-rate two-photon sampling in vivo with increased stability and sensitivity. Combining a soma-targeted ASAP3 variant and ULoVE, we show single-trial tracking of spikes and subthreshold events for minutes in deep locations, with subcellular resolution and with repeated sampling over days. In the …

Chronic Muscle Weakness And Mitochondrial Dysfunction In The Absence Of Sustained Atrophy In A Preclinical Sepsis Model, Allison M. Owen, Samir P. Patel, Jeffrey D. Smith, Beverly K. Balasuriya, Stephanie F. Mori, Gregory S. Hawk, Arnold J. Stromberg, Naohide Kuriyama, Masao Kaneki, Alexander G. Rabchevsky, Timothy A. Butterfield, Karyn A. Esser, Charlotte A. Peterson, Marlene E. Starr, Hiroshi Saito

Physiology Faculty Publications

Chronic critical illness is a global clinical issue affecting millions of sepsis survivors annually. Survivors report chronic skeletal muscle weakness and development of new functional limitations that persist for years. To delineate mechanisms of sepsis-induced chronic weakness, we first surpassed a critical barrier by establishing a murine model of sepsis with ICU-like interventions that allows for the study of survivors. We show that sepsis survivors have profound weakness for at least 1 month, even after recovery of muscle mass. Abnormal mitochondrial ultrastructure, impaired respiration and electron transport chain activities, and persistent protein oxidative damage were evident in the muscle of …

Defining The Layers Of A Sensory Cilium With Storm And Cryoelectron Nanoscopy, Michael A Robichaux, Valencia L Potter, Zhixian Zhang, Feng He, Jun Liu, Michael F Schmid, Theodore G Wensel

Faculty, Staff and Students Publications

Primary cilia carry out numerous signaling and sensory functions, and defects in them, "ciliopathies," cause a range of symptoms, including blindness. Understanding of their nanometer-scale ciliary substructures and their disruptions in ciliopathies has been hindered by limitations of conventional microscopic techniques. We have combined cryoelectron tomography, enhanced by subtomogram averaging, with superresolution stochastic optical reconstruction microscopy (STORM) to define subdomains within the light-sensing rod sensory cilium of mouse retinas and reveal previously unknown substructures formed by resident proteins. Domains are demarcated by structural features such as the axoneme and its connections to the ciliary membrane, and are correlated with molecular …