Medical Specialties Commons^™

Infiltration Of Peripheral Immune Cells Into The Olfactory Bulb In A Mouse Model Of Acute Nasal Inflammation, Hinami Asano, Sanae Hasegawa-Ishii, Ken Arae, Aki Obara, Geoffroy Laumet, Robert Dantzer, Atsuyoshi Shimada

Faculty, Staff and Student Publications

Chronic nasal inflammation induces robust olfactory bulb (OB) atrophy in mice. Here we examined initial events that occur in the OB after bilateral intranasal administration of lipopolysaccharide, focusing on the olfactory nerve fibers and meninges. We analyzed the time course of OB and meninges inflammation using histological and biochemical approaches. Within 12 h, we observed increased chemokine expression and transient infiltration of peripheral immune cells into the OB, resulting in the development of pro-inflammatory status in the OB. Meningeal immunity was activated. Resident microglia produced anti-inflammatory cytokines within 24 h. These could be the initial events that lead to OB …

Gut Bacterial Isoamylamine Promotes Age-Related Cognitive Dysfunction By Promoting Microglial Cell Death, Yun Teng, Jingyao Mu, Fangyi Xu, Xiangcheng Zhang, Mukesh K Sriwastva, Qiaohong M Liu, Xiaohong Li, Chao Lei, Kumaran Sundaram, Xin Hu, Lifeng Zhang, Juw Won Park, Jae Yeon Hwang, Eric C Rouchka, Xiang Zhang, Jun Yan, Michael L Merchant, Huang-Ge Zhang

Faculty, Staff and Student Publications

The intestinal microbiome releases a plethora of small molecules. Here, we show that the Ruminococcaceae metabolite isoamylamine (IAA) is enriched in aged mice and elderly people, whereas Ruminococcaceae phages, belonging to the Myoviridae family, are reduced. Young mice orally administered IAA show cognitive decline, whereas Myoviridae phage administration reduces IAA levels. Mechanistically, IAA promotes apoptosis of microglial cells by recruiting the transcriptional regulator p53 to the S100A8 promoter region. Specifically, IAA recognizes and binds the S100A8 promoter region to facilitate the unwinding of its self-complementary hairpin structure, thereby subsequently enabling p53 to access the S100A8 promoter and enhance S100A8 expression. …

The Testis-Specific E3 Ubiquitin Ligase Rnf133 Is Required For Fecundity In Mice, Kaori Nozawa, Yoshitaka Fujihara, Darius J Devlin, Ricardo E Deras, Katarzyna Kent, Irina V Larina, Kohei Umezu, Zhifeng Yu, Courtney M Sutton, Qiuji Ye, Laura K Dean, Chihiro Emori, Masahito Ikawa, Thomas X Garcia, Martin M Matzuk

Faculty, Staff and Students Publications

BACKGROUND: Ubiquitination is a post-translational modification required for a number of physiological functions regulating protein homeostasis, such as protein degradation. The endoplasmic reticulum (ER) quality control system recognizes and degrades proteins no longer needed in the ER through the ubiquitin-proteasome pathway. E2 and E3 enzymes containing a transmembrane domain have been shown to function in ER quality control. The ER transmembrane protein UBE2J1 is a E2 ubiquitin-conjugating enzyme reported to be essential for spermiogenesis at the elongating spermatid stage. Spermatids from Ube2j1 KO male mice are believed to have defects in the dislocation step of ER quality control. However, associated …

Renin-Angiotensin System In Huntington's Disease: Evidence From Animal Models And Human Patients, Lucas M Kangussu, Natalia P Rocha, Priscila A C Valadão, Thatiane C G Machado, Kívia B Soares, Julliane V Joviano-Santos, Leigh B Latham, Gabriela D Colpo, Ana Flávia Almeida-Santos, Erin Furr Stimming, Ana Cristina Simões E Silva, Antônio L Teixeira, Aline Silva Miranda, Cristina Guatimosim

Faculty, Staff and Student Publications

The Renin-Angiotensin System (RAS) is expressed in the central nervous system and has important functions that go beyond blood pressure regulation. Clinical and experimental studies have suggested that alterations in the brain RAS contribute to the development and progression of neurodegenerative diseases. However, there is limited information regarding the involvement of RAS components in Huntington's disease (HD). Herein, we used the HD murine model, (BACHD), as well as samples from patients with HD to investigate the role of both the classical and alternative axes of RAS in HD pathophysiology. BACHD mice displayed worse motor performance in different behavioral tests alongside …

Metabolic Requirement For Got2 In Pancreatic Cancer Depends On Environmental Context, Samuel A Kerk, Lin Lin, Amy L Myers, Damien J Sutton, Anthony Andren, Peter Sajjakulnukit, Li Zhang, Yaqing Zhang, Jennifer A Jiménez, Barbara S Nelson, Brandon Chen, Anthony Robinson, Galloway Thurston, Samantha B Kemp, Nina G Steele, Megan T Hoffman, Hui-Ju Wen, Daniel Long, Sarah E Ackenhusen, Johanna Ramos, Xiaohua Gao, Zeribe C Nwosu, Stefanie Galban, Christopher J Halbrook, David B Lombard, David R Piwnica-Worms, Haoqiang Ying, Marina Pasca Di Magliano, Howard C Crawford, Yatrik M Shah, Costas A Lyssiotis

Faculty, Staff and Student Publications

Mitochondrial glutamate-oxaloacetate transaminase 2 (GOT2) is part of the malate-aspartate shuttle, a mechanism by which cells transfer reducing equivalents from the cytosol to the mitochondria. GOT2 is a key component of mutant KRAS (KRAS*)-mediated rewiring of glutamine metabolism in pancreatic ductal adenocarcinoma (PDA). Here, we demonstrate that the loss of GOT2 disturbs redox homeostasis and halts proliferation of PDA cells in vitro. GOT2 knockdown (KD) in PDA cell lines in vitro induced NADH accumulation, decreased Asp and α-ketoglutarate (αKG) production, stalled glycolysis, disrupted the TCA cycle, and impaired proliferation. Oxidizing NADH through chemical or genetic means resolved the redox imbalance …

Small Rna Signatures Of Acute Ischemic Stroke In L1cam Positive Extracellular Vesicles, Michael A Lopez, Ying Si, Xianzhen Hu, Valentyna Williams, Fuad Qushair, Jackson Carlyle, Lyndsy Alesce, Michael Conklin, Shawn Gilbert, Marcas M Bamman, Matthew S Alexander, Peter H King

Faculty, Staff and Student Publications

Duchenne muscular dystrophy (DMD) is an X-linked recessive disease characterized by skeletal muscle instability, progressive muscle wasting, and fibrosis. A major driver of DMD pathology stems from aberrant upregulation of transforming growth factor β (TGFβ) signaling. In this report, we investigated the major transducers of TGFβ signaling, i.e., receptor Smads (R-Smads), in DMD patient skeletal muscle and observed a 48-fold increase in Smad8 mRNA. Smad1, Smad2, Smad3, and Smad5 mRNA were only minimally increased. A similar pattern was observed in the muscle from the mdx5cv mouse. Western blot analysis showed upregulation of phosphorylated Smad1, Smad5, and Smad8 …

Extracellular Domain Of Pept1 Interacts With Tm1 To Facilitate Substrate Transport, Jiemin Shen, Miaohui Hu, Xiao Fan, Zhenning Ren, Corinne Portioli, Xiuwen Yan, Mingqiang Rong, Ming Zhou

Faculty, Staff and Students Publications

Mammalian peptide transporters, PepT1 and PepT2, mediate uptake of small peptides and are essential for their absorption. PepT also mediates absorption of many drugs and prodrugs to enhance their bioavailability. PepT has twelve transmembrane (TM) helices that fold into an N-terminal domain (NTD, TM1–6) and a C-terminal domain (CTD, TM7–12), and has a large extracellular domain (ECD) between TM9–10. It is well-recognized that peptide transport requires movements of the NTD and CTD, but the role of the ECD in PepT1 remains unclear. Here we report the structure of horse PepT1 encircled in lipid nanodiscs and captured in the inward-open apo …

Gene-Based Therapeutics For Rare Genetic Neurodevelopmental Psychiatric Disorders, Beverly L Davidson, Guangping Gao, Elizabeth Berry-Kravis, Allison M Bradbury, Carsten Bönnemann, Joseph D Buxbaum, Gavin R Corcoran, Steven J Gray, Heather Gray-Edwards, Robin J Kleiman, Adam J Shaywitz, Dan Wang, Huda Y Zoghbi, Terence R Flotte, Sitra Tauscher-Wisniewski, Cynthia J Tifft, Mustafa Sahin

Duncan NRI Faculty and Staff Publications

We are in an emerging era of gene-based therapeutics with significant promise for rare genetic disorders. The potential is particularly significant for genetic central nervous system disorders that have begun to achieve Food and Drug Administration approval for select patient populations. This review summarizes the discussions and presentations of the National Institute of Mental Health-sponsored workshop "Gene-Based Therapeutics for Rare Genetic Neurodevelopmental Psychiatric Disorders," which was held in January 2021. Here, we distill the points raised regarding various precision medicine approaches related to neurodevelopmental and psychiatric disorders that may be amenable to gene-based therapies.

Vitamin E Enhances Cancer Immunotherapy By Reinvigorating Dendritic Cells Via Targeting Checkpoint Shp1, Xiangliang Yuan, Yimin Duan, Yi Xiao, Kai Sun, Yutao Qi, Yuan Zhang, Zamal Ahmed, Davide Moiani, Jun Yao, Hongzhong Li, Lin Zhang, Arseniy E Yuzhalin, Ping Li, Chenyu Zhang, Akosua Badu-Nkansah, Yohei Saito, Xianghua Liu, Wen-Ling Kuo, Haoqiang Ying, Shao-Cong Sun, Jenny C Chang, John A Tainer, Dihua Yu

Faculty, Staff and Student Publications

Despite the popular use of dietary supplements during conventional cancer treatments, their impacts on the efficacies of prevalent immunotherapies, including immune-checkpoint therapy (ICT), are unknown. Surprisingly, our analyses of electronic health records revealed that ICT-treated patients with cancer who took vitamin E (VitE) had significantly improved survival. In mouse models, VitE increased ICT antitumor efficacy, which depended on dendritic cells (DC). VitE entered DCs via the SCARB1 receptor and restored tumor-associated DC functionality by directly binding to and inhibiting protein tyrosine phosphatase SHP1, a DC-intrinsic checkpoint. SHP1 inhibition, genetically or by VitE treatment, enhanced tumor antigen cross-presentation by DCs and …

The Use Of Second-Generation Antipsychotics And The Changes In Physical Growth In Children And Adolescents With Perinatally Acquired Hiv, Nan Xin, Jenni Durieux, Chunxia Yang, Suzanne Wolff, Hyun-Eui Kim, Andrew Dillin

Faculty, Staff and Student Publications

The mitochondrial unfolded protein response (UPRmt) is dedicated to promoting mitochondrial proteostasis and is linked to extreme longevity. The key regulator of this process is the transcription factor ATFS-1, which, upon UPRmt activation, is excluded from the mitochondria and enters the nucleus to regulate UPRmt genes. However, the repair proteins synthesized as a direct result of UPRmt activation must be transported into damaged mitochondria that had previously excluded ATFS-1 owing to reduced import efficiency. To address this conundrum, we analyzed the role of the import machinery when the UPRmt was induced. Using in vitro and in vivo analysis of mitochondrial …

Transcription Factor Runx3 Mediates Plasticity Of Thgm Cells Toward Th1 Phenotype, Javad Rasouli, Giacomo Casella, Weifeng Zhang, Dan Xiao, Gaurav Kumar, Paolo Fortina, Guang-Xian Zhang, Bogoljub Ciric, Abdolmohamad Rostami

Department of Neurology Faculty Papers

GM-CSF-producing T helper (Th) cells play a crucial role in the pathogenesis of autoimmune diseases such as multiple sclerosis (MS). Recent studies have identified a distinct population of GM-CSF-producing Th cells, named ThGM cells, that also express cytokines TNF, IL-2, and IL-3, but lack expression of master transcription factors (TF) and signature cytokines of commonly recognized Th cell lineages. ThGM cells are highly encephalitogenic in a mouse model of MS, experimental autoimmune encephalomyelitis (EAE). Similar to Th17 cells, in response to IL-12, ThGM cells upregulate expression of T-bet and IFN-γ and switch their phenotype to Th1. Here we show that …

Effects Of Combined Gentamicin And Furosemide Treatment On Cochlear Macrophages, Liana Sargsyan, Austin R Swisher, Alisa P Hetrick, Hongzhe Li

Faculty, Staff and Student Publications

Combining aminoglycosides and loop diuretics often serves as an effective ototoxic approach to deafen experimental animals. The treatment results in rapid hair cell loss with extended macrophage presence in the cochlea, creating a sterile inflammatory environment. Although the early recruitment of macrophages is typically neuroprotective, the delay in the resolution of macrophage activity can be a complication if the damaged cochlea is used as a model to study subsequent therapeutic strategies. Here, we applied a high dose combination of systemic gentamicin and furosemide in

Alyref, A Novel Factor Involved In Breast Carcinogenesis, Acts Through Transcriptional And Post-Transcriptional Mechanisms Selectively Regulating The Short Neat1 Isoform, Christiane Klec, Erik Knutsen, Daniela Schwarzenbacher, Katharina Jonas, Barbara Pasculli, Ellen Heitzer, Beate Rinner, Katarina Krajina, Felix Prinz, Benjamin Gottschalk, Peter Ulz, Alexander Deutsch, Andreas Prokesch, Stephan W Jahn, S Mohammad Lellahi, Maria Perander, Raffaela Barbano, Wolfgang F Graier, Paola Parrella, George Adrian Calin, Martin Pichler

Faculty, Staff and Student Publications

The RNA-binding protein ALYREF (THOC4) is involved in transcriptional regulation and nuclear mRNA export, though its role and molecular mode of action in breast carcinogenesis are completely unknown. Here, we identified high ALYREF expression as a factor for poor survival in breast cancer patients. ALYREF significantly influenced cellular growth, apoptosis and mitochondrial energy metabolism in breast cancer cells as well as breast tumorigenesis in orthotopic mouse models. Transcriptional profiling, phenocopy and rescue experiments identified the short isoform of the lncRNA NEAT1 as a molecular trigger for ALYREF effects in breast cancer. Mechanistically, we found that ALYREF binds to the NEAT1 …

Redirecting Host Preexisting Influenza A Virus Immunity For Cancer Immunotherapy, Bharat K R Chaganty, Songbo Qiu, Yang Lu, Gabriel Lopez-Berestein, Bulent Ozpolat, Zhen Fan

Faculty, Staff and Student Publications

We tested the concept that host preexisting influenza A virus immunity can be redirected to inhibit tumor growth and metastasis through systemic administration of influenza A virus-related peptides to targeted tumors. Mice infected with influenza A virus strain A/Puerto Rico/8/34 (PR8) were used as a model of a host with preexisting viral immunity. The extent to which preexisting influenza A immunity in PR8-immunized mice can be redirected to inhibit tumor growth and metastasis was first examined by ectopic expression of influenza A nucleoprotein (NP) and hemagglutinin (HA) in syngeneic mammary tumor cells via lentiviral transduction. Then, the feasibility of implementing …

Mice Lacking Wnt9a Or Wnt4 Are Prone To Develop Spontaneous Osteoarthritis With Age And Display Alteration In Either The Trabecular Or Cortical Bone Compartment, Stefan Teufel, Lena Wolff, Ulrich König, Akio Kobayashi, Richard Behringer, Christine Hartmann

Faculty, Staff and Student Publications

Osteoarthritis (OA) is a common degenerative disease of the joint, with a complex multifactorial not yet fully understood etiology. Over the past years, the Wnt signaling pathway has been implicated in osteoarthritis. In a recent genomewide association study (GWAS), the chromosomal location on chromosome 1, linked to the Wnt3a-Wnt9a gene locus, was identified as the most significant locus associated with a thumb osteoarthritis endophenotype. Previously, it was shown that WNT9a is involved in maintaining synovial cell identity in the elbow joint during embryogenesis. Here, we report that the conditional loss of Wnt9a in the Prx1-Cre expressing limb mesenchyme or Prg4-CreER …

Opposing Roles Of Hdac6 In Liver Regeneration And Hepatocarcinogenesis, Sophors Phorl, Azra Memon, Yuri Seo, Thi Oanh Hoang, Trung Nghia Tran, Le Minh Tri Nguyen, Chang Hoon Lee, Woon Kyu Lee, Joo-Yong Lee

Faculty, Staff and Student Publications

Histone deacetylase 6 (HDAC6), a deacetylase of p53, has emerged as a privileged inhibitory target for cancer therapy because of its deacetylating activity for p53 at K120 and K373/382. However, intricate roles of HDAC6 in hepatocellular carcinogenesis have been suggested by recent evidence, namely that HDAC6 ablation suppresses innate immunity, which plays critical roles in tumor immunosurveillance and antitumor immune responses. Therefore, it is valuable to determine whether HDAC6 ablation inhibits hepatocellular carcinogenesis using in vivo animal models. Here, we firstly showed that HDAC6 ablation increased K320 acetylation of p53, known as pro-survival acetylation, in all tested animal models but …

Hap40 Is A Conserved Central Regulator Of Huntingtin And A Potential Modulator Of Huntington’S Disease Pathogenesis, Shiyu Xu, Gang Li, Xin Ye, Dongsheng Chen, Zhihua Chen, Zhen Xu, Moretti Daniele, Sara Tambone, Alessandra Ceccacci, Licia Tomei, Lili Ye, Yue Yu, Amanda Solbach, Stephen M Farmer, Erin Furr Stimming, George Mcallister, Deanna M Marchionini, Sheng Zhang

Faculty, Staff and Student Publications

Perturbation of huntingtin (HTT)'s physiological function is one postulated pathogenic factor in Huntington's disease (HD). However, little is known how HTT is regulated in vivo. In a proteomic study, we isolated a novel ~40kDa protein as a strong binding partner of Drosophila HTT and demonstrated it was the functional ortholog of HAP40, an HTT associated protein shown recently to modulate HTT's conformation but with unclear physiological and pathologic roles. We showed that in both flies and human cells, HAP40 maintained conserved physical and functional interactions with HTT. Additionally, loss of HAP40 resulted in similar phenotypes as HTT knockout. More strikingly, …

Prolonged Cardiac Nr4a2 Aactivation Causes Dilated Cardiomyopathy In Mice, Sadia Ashraf, Heinrich Taegtmeyer, Romain Harmancey

Faculty, Staff and Student Publications

Transcription factors play a fundamental role in cardiovascular adaptation to stress. Nuclear receptor subfamily 4 group A member 2 (NR4A2; NURR1) is an immediate-early gene and transcription factor with a versatile role throughout many organs. In the adult mammalian heart, and particularly in cardiac myocytes, NR4A2 is strongly up-regulated in response to beta-adrenergic stimulation. The physiologic implications of this increase remain unknown. In this study, we aimed to interrogate the consequences of cardiac NR4A2 up-regulation under normal conditions and in response to pressure overload. In mice, tamoxifen-dependent, cardiomyocyte-restricted overexpression of NR4A2 led to cardiomyocyte hypertrophy, left ventricular dilation, heart failure, …

Guidelines On Models Of Diabetic Heart Disease, Lisa C Heather, Anne D Hafstad, Ganesh V Halade, Romain Harmancey, Kimberley M Mellor, Paras K Mishra, Erin E Mulvihill, Miranda Nabben, Michinari Nakamura, Oliver J Rider, Matthieu Ruiz, Adam R Wende, John R Ussher

Faculty, Staff and Student Publications

Diabetes is a major risk factor for cardiovascular diseases, including diabetic cardiomyopathy, atherosclerosis, myocardial infarction, and heart failure. As cardiovascular disease represents the number one cause of death in people with diabetes, there has been a major emphasis on understanding the mechanisms by which diabetes promotes cardiovascular disease, and how antidiabetic therapies impact diabetic heart disease. With a wide array of models to study diabetes (both type 1 and type 2), the field has made major progress in answering these questions. However, each model has its own inherent limitations. Therefore, the purpose of this guidelines document is to provide the …

Reshaping The Tumor Microenvironment With Oncolytic Viruses, Positive Regulation Of The Immune Synapse, And Blockade Of The Immunosuppressive Oncometabolic Circuitry, Teresa T Nguyen, Dong Ho Shin, Sagar Sohoni, Sanjay K Singh, Yisel Rivera-Molina, Hong Jiang, Xuejun Fan, Joy Gumin, Frederick F Lang, Christopher Alvarez-Breckenridge, Filipa Godoy-Vitorino, Lisha Zhu, W Jim Zheng, Lijie Zhai, Erik Ladomersky, Kristen L Lauing, Marta M Alonso, Derek A Wainwright, Candelaria Gomez-Manzano, Juan Fueyo

Faculty, Staff and Student Publications

Background: Oncolytic viruses are considered part of immunotherapy and have shown promise in preclinical experiments and clinical trials. Results from these studies have suggested that tumor microenvironment remodeling is required to achieve an effective response in solid tumors. Here, we assess the extent to which targeting specific mechanisms underlying the immunosuppressive tumor microenvironment optimizes viroimmunotherapy.

Methods: We used RNA-seq analyses to analyze the transcriptome, and validated the results using Q-PCR, flow cytometry, and immunofluorescence. Viral activity was analyzed by replication assays and viral titration. Kyn and Trp metabolite levels were quantified using liquid chromatography-mass spectrometry. Aryl hydrocarbon receptor (AhR) activation …

Prolonged Cardiac Nr4a2 Activation Causes Dilated Cardiomyopathy In Mice, Sadia Ashraf, Heinrich Taegtmeyer, Romain Harmancey

Faculty, Staff and Student Publications

Transcription factors play a fundamental role in cardiovascular adaptation to stress. Nuclear receptor subfamily 4 group A member 2 (NR4A2; NURR1) is an immediate-early gene and transcription factor with a versatile role throughout many organs. In the adult mammalian heart, and particularly in cardiac myocytes, NR4A2 is strongly up-regulated in response to beta-adrenergic stimulation. The physiologic implications of this increase remain unknown. In this study, we aimed to interrogate the consequences of cardiac NR4A2 up-regulation under normal conditions and in response to pressure overload. In mice, tamoxifen-dependent, cardiomyocyte-restricted overexpression of NR4A2 led to cardiomyocyte hypertrophy, left ventricular dilation, heart failure, …

Prospecting Cellular Gold Nanoparticle Biomineralization As A Viable Alternative To Prefabricated Gold Nanoparticles, Aaron S Schwartz-Duval, Konstantin V Sokolov

Faculty, Staff and Student Publications

Gold nanoparticles (GNPs) have shown considerable potential in a vast number of biomedical applications. However, currently there are no clinically approved injectable GNP formulations. Conversely, gold salts have been used in the clinic for nearly a century. Further, there is evidence of GNP formation in patients treated with gold salts (i.e., chrysiasis). Recent reports evaluating this phenomenon in human cells and in murine models indicate that the use of gold ions for in situ formation of theranostic GNPs could greatly improve the delivery within dense biological tissues, increase efficiency of intracellular gold uptake, and specificity of GNP formation within cancer …

A Role For Insulin-Like Growth Factor 1 In The Generation Of Epileptic Spasms In A Murine Model, Carlos J Ballester-Rosado, John T Le, Trang T Lam, Carrie A Mohila, Sandi Lam, Anne E Anderson, James D Frost, John W Swann

Faculty, Staff and Students Publications

Objective: Infantile spasms are associated with a wide variety of clinical conditions, including perinatal brain injuries. We have created a model in which prolonged infusion of tetrodotoxin (TTX) into the neocortex, beginning in infancy, produces a localized lesion and reproduces the behavioral spasms, electroencephalogram (EEG) abnormalities, and drug responsiveness seen clinically. Here, we undertook experiments to explore the possibility that the growth factor IGF-1 plays a role in generating epileptic spasms.

Methods: We combined long-term video EEG recordings with quantitative immunohistochemical and biochemical analyses to unravel IGF-1's role in spasm generation. Immunohistochemistry was undertaken in surgically resected tissue from infantile …

Regulation Of Pgc1Α Downstream Of The Insulin Signaling Pathway Plays A Role In The Hepatic Proteotoxicity Of Mutant Α1-Antitrypsin Deficiency Variant Z, David A Rudnick, Jiansheng Huang, Tunda Hidvegi, Andrew S Chu, Pamela Hale, Admire Munanairi, Dennis J Dietzen, Paul F Cliften, Eric Tycksen, Andrew J Lutkewitte, Brian N Finck, Stephen C Pak, Gary A Silverman, David H Perlmutter

Faculty, Staff and Students Publications

BACKGROUND & AIMS: Insulin signaling is known to regulate essential proteostasis mechanisms.

METHODS: The analyses here examined effects of insulin signaling in the PiZ mouse model of α1-antitrypsin deficiency in which hepatocellular accumulation and proteotoxicity of the misfolded α1-antitrypsin Z variant (ATZ) causes liver fibrosis and cancer.

RESULTS: We first studied the effects of breeding PiZ mice to liver-insulin-receptor knockout (LIRKO) mice (with hepatocyte-specific insulin-receptor gene disruption). The results showed decreased hepatic ATZ accumulation and liver fibrosis in PiZ x LIRKO vs PiZ mice, with reversal of those effects when we bred PiZ x LIRKO mice onto a FOXO1-deficient background. …

Cholestasis Alters Brain Lipid And Bile Acid Composition And Compromises Motor Function In Neonatal Piglets, Nicole Lind Henriksen, Svend Høime Hansen, Matthew Domenic Lycas, Xiaoyu Pan, Thomas Eriksen, Lars Søndergaard Johansen, Richard R Sprenger, Christer Stenby Ejsing, Douglas G Burrin, Kerstin Skovgaard, Vibeke Brix Christensen, Thomas Thymann, Stanislava Pankratova

Faculty, Staff and Students Publications

Infants with neonatal cholestasis are prone to neurodevelopmental deficits, however, the underlying pathogenesis is unclear. Lipid malabsorption and accumulation of potentially neurotoxic molecules in the blood such as bile acids are important yet relatively unexplored pathways. Here, we developed a translational piglet model to understand how the molecular bile acid and lipid composition of the brain is affected by this disease and relates to motor function. Piglets (8-days old) had bile duct ligation or sham surgery and were fed a formula diet for 3 weeks. Alongside sensory-motor deficits observed in bile duct-ligated animals, we found a shift toward a more …

Kalium Channelrhodopsins Are Natural Light-Gated Potassium Channels That Mediate Optogenetic Inhibition, Elena G Govorunova, Yueyang Gou, Oleg A Sineshchekov, Hai Li, Xiaoyu Lu, Yumei Wang, Leonid S Brown, François St-Pierre, Mingshan Xue, John L Spudich

Faculty, Staff and Student Publications

Channelrhodopsins are used widely for optical control of neurons, in which they generate photoinduced proton, sodium or chloride influx. Potassium (K+) is central to neuron electrophysiology, yet no natural K+-selective light-gated channel has been identified. Here, we report kalium channelrhodopsins (KCRs) from Hyphochytrium catenoides. Previously known gated potassium channels are mainly ligand- or voltage-gated and share a conserved K+-selectivity filter. KCRs differ in that they are light-gated and have independently evolved an alternative K+ selectivity mechanism. The KCRs are potent, highly selective of K+ over Na+, and open in less than 1 ms following photoactivation. The permeability ratio PK/PNa of …

High-Throughput Profiling Of Histone Post-Translational Modifications And Chromatin Modifying Proteins By Reverse Phase Protein Array, Xuan Wang, Zhongcheng Shi, Hsin-Yi Lu, Jean J Kim, Wen Bu, Jose A Villalobos, Dimuthu N Perera, Sung Yun Jung, Tao Wang, Sandra L Grimm, Bethany C Taylor, Kimal Rajapakshe, Hyekyung Park, Julia Wulfkuhle, Nicolas L Young, Yi Li, Cristian Coarfa, Dean P Edwards, Shixia Huang

Faculty, Staff and Students Publications

Epigenetic variation plays a significant role in normal development and human diseases including cancer, in part through post-translational modifications (PTMs) of histones. Identification and profiling of changes in histone PTMs, and in proteins regulating PTMs, are crucial to understanding diseases, and for discovery of epigenetic therapeutic agents. In this study, we have adapted and validated an antibody-based reverse phase protein array (RPPA) platform for profiling 20 histone PTMs and expression of 40 proteins that modify histones and other epigenomic regulators. The specificity of the RPPA assay for histone PTMs was validated with synthetic peptides corresponding to histone PTMs and by …

The Evolution And Structure/Function Of Bhlh-Pas Transcription Factor Family, Hailey E Edwards, Daniel A Gorelick

Faculty, Staff and Students Publications

Proteins that contain basic helix-loop-helix (bHLH) and Per-Arnt-Sim motifs (PAS) function as transcription factors. bHLH-PAS proteins exhibit essential and diverse functions throughout the body, from cell specification and differentiation in embryonic development to the proper function of organs like the brain and liver in adulthood. bHLH-PAS proteins are divided into two classes, which form heterodimers to regulate transcription. Class I bHLH-PAS proteins are typically activated in response to specific stimuli, while class II proteins are expressed more ubiquitously. Here, we discuss the general structure and functions of bHLH-PAS proteins throughout the animal kingdom, including family members that do not fit …

Regulation Of Age-Associated Insulin Resistance By Mt1-Mmp-Mediated Cleavage Of Insulin Receptor, Xuanming Guo, Pallavi Asthana, Susma Gurung, Shuo Zhang, Sheung Kin Ken Wong, Samane Fallah, Chi Fung Willis Chow, Sijia Che, Lixiang Zhai, Zening Wang, Xin Ge, Zhixin Jiang, Jiayan Wu, Yijing Zhang, Xiaoyu Wu, Keyang Xu, Cheng Yuan Lin, Hiu Yee Kwan, Aiping Lyu, Zhongjun Zhou, Zhao-Xiang Bian, Hoi Leong Xavier Wong

Faculty, Staff and Student Publications

Insulin sensitivity progressively declines with age. Currently, the mechanism underlying age-associated insulin resistance remains unknown. Here, we identify membrane-bound matrix metalloproteinase 14 (MT1-MMP/MMP14) as a central regulator of insulin sensitivity during ageing. Ageing promotes MMP14 activation in insulin-sensitive tissues, which cleaves Insulin Receptor to suppress insulin signaling. MT1-MMP inhibition restores Insulin Receptor expression, improving insulin sensitivity in aged mice. The cleavage of Insulin Receptor by MT1-MMP also contributes to obesity-induced insulin resistance and inhibition of MT1-MMP activities normalizes metabolic dysfunctions in diabetic mouse models. Conversely, overexpression of MT1-MMP in the liver reduces the level of Insulin Receptor, impairing hepatic insulin …

Dietary Fatty Acid Intake And The Colonic Gut Microbiota In Humans, Anthony A Xu, Luke K Kennedy, Kristi Hoffman, Donna L White, Fasiha Kanwal, Hashem B El-Serag, Joseph F Petrosino, Li Jiao

Faculty, Staff and Students Publications

A high-fat diet has been associated with systemic diseases in humans and alterations in gut microbiota in animal studies. However, the influence of dietary fatty acid intake on gut microbiota in humans has not been well studied. In this cross-sectional study, we examined the association between intake of total fatty acids (TFAs), saturated fatty acids (SFAs), trans fatty acids (TrFAs), monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), n3-FAs, and n6-FAs, and the community composition and structure of the adherent colonic gut microbiota. We obtained 97 colonic biopsies from 34 participants with endoscopically normal colons. Microbial DNA was used to …