Biochemistry, Biophysics, and Structural Biology Commons^™

Nuclear Localization Of A Novel Calpain-2 Mediated Junctophilin-2 C-Terminal Cleavage Peptide Promotes Cardiomyocyte Remodeling, Satadru K Lahiri, Ann P Quick, Benoit Samson-Couterie, Mohit Hulsurkar, Ies Elzenaar, Ralph J Van Oort, Xander H T Wehrens

Faculty, Staff and Students Publications

Heart failure (HF) is a leading cause of morbidity and mortality worldwide. Patients with HF exhibit a loss of junctophilin-2 (JPH2), a structural protein critical in forming junctional membrane complexes in which excitation-contraction takes place. Several mechanisms have been proposed to mediate the loss of JPH2, one being cleavage by the calcium-dependent protease calpain. The downstream mechanisms underlying HF progression after JPH2 cleavage are presently poorly understood. In this study, we used Labcas to bioinformatically predict putative calpain cleavage sites on JPH2. We identified a cleavage site that produces a novel C-terminal JPH2 peptide (JPH2-CTP) using several domain-specific antibodies. Western …

Acute Tubular Injury In A Patient On A Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitor, June K Pickett, Maulin Shah, Michael Gillette, Peter Jones, Salim Virani, Christie Ballantyne, Vijay Nambi

Faculty, Staff and Students Publications

A 72-year-old man with coronary artery disease, statin intolerance, and chronic kidney disease stage IIIa was initiated on alirocumab, a proprotein convertase subtilisin/kexin type 9 inhibitor, and developed acute kidney injury. A kidney biopsy was performed and suggested acute tubular injury. The serum creatinine returned to baseline after discontinuation of alirocumab. (Level of Difficulty: Intermediate.)

Aav-Crispr Gene Editing Is Negated By Pre-Existing Immunity To Cas9, Ang Li, Mark R Tanner, Ciaran M Lee, Ayrea E Hurley, Marco De Giorgi, Kelsey E Jarrett, Timothy H Davis, Alexandria M Doerfler, Gang Bao, Christine Beeton, William R Lagor

Faculty, Staff and Students Publications

Adeno-associated viral (AAV) vectors are a leading candidate for the delivery of CRISPR-Cas9 for therapeutic genome editing in vivo. However, AAV-based delivery involves persistent expression of the Cas9 nuclease, a bacterial protein. Recent studies indicate a high prevalence of neutralizing antibodies and T cells specific to the commonly used Cas9 orthologs from Streptococcus pyogenes (SpCas9) and Staphylococcus aureus (SaCas9) in humans. We tested in a mouse model whether pre-existing immunity to SaCas9 would pose a barrier to liver genome editing with AAV packaging CRISPR-Cas9. Although efficient genome editing occurred in mouse liver with pre-existing SaCas9 immunity, this was accompanied by …

Rapid And Efficient Synthetic Assembly Of Multiplex Luciferase Reporter Plasmids For The Simultaneous Monitoring Of Up To Six Cellular Signaling Pathways, Alejandro Sarrion-Perdigones, Yezabel Gonzalez, Koen J T Venken

Faculty, Staff and Students Publications

High-throughput cell-based screening assays are valuable tools in the discovery of chemical probes and therapeutic agents. Such assays are designed to examine the effects of small compounds on targets, pathways, or phenotypes participating in normal and disease processes. While most cell-based assays measure single quantities, multiplexed assays seek to address these limitations by obtaining multiple simultaneous measurements. The signals from such measurements should be independently detectable and cover large dynamic ranges. Luciferases are good candidates for generation of such signals. They are genetically encoded, versatile, and cost-effective, and their output signals can be sensitively detected. We recently developed a multiplex …

Simultaneous Examination Of Cellular Pathways Using Multiplex Hextuple Luciferase Assaying, Alejandro Sarrion-Perdigones, Lyra Chang, Yezabel Gonzalez, Tatiana Gallego-Flores, Damian W Young, Koen J T Venken

Faculty, Staff and Students Publications

Multiplex experimentation that can assay multiple cellular signaling pathways in the same cells requires orthogonal genetically encoded reporters that report over large dynamic ranges. Luciferases are cost-effective, versatile candidates whose output signals can be sensitively detected in a multiplex fashion. Commonly used dual luciferase reporter assays detect one luciferase that is coupled to a single cellular pathway, and a second that is coupled to a control pathway for normalization purposes. We expanded this approach to multiplex hextuple luciferase assaying that can report on five cellular signaling pathways and one control, each of which is encoded by a unique luciferase. Light …

Pooled Crispr Screens With Imaging On Microraft Arrays Reveals Stress Granule-Regulatory Factors, Emily C Wheeler, Anthony Q Vu, Jaclyn M Einstein, Matthew Disalvo, Noorsher Ahmed, Eric L Van Nostrand, Alexander A Shishkin, Wenhao Jin, Nancy L Allbritton, Gene W Yeo

Faculty, Staff and Students Publications

Genetic screens using pooled CRISPR-based approaches are scalable and inexpensive, but restricted to standard readouts, including survival, proliferation and sortable markers. However, many biologically relevant cell states involve cellular and subcellular changes that are only accessible by microscopic visualization, and are currently impossible to screen with pooled methods. Here we combine pooled CRISPR-Cas9 screening with microraft array technology and high-content imaging to screen image-based phenotypes (CRaft-ID; CRISPR-based microRaft followed by guide RNA identification). By isolating microrafts that contain genetic clones harboring individual guide RNAs (gRNA), we identify RNA-binding proteins (RBPs) that influence the formation of stress granules, the punctate protein-RNA …

Age-Dependent Involvement Of Gut Mast Cells And Histamine In Post-Stroke Inflammation, Maria Pilar Blasco, Anjali Chauhan, Pedram Honarpisheh, Hilda Ahnstedt, John D'Aigle, Arunkumar Ganesan, Sriram Ayyaswamy, Frank Blixt, Susan Venable, Angela Major, David Durgan, Anthony Haag, Julia Kofler, Robert Bryan, Louise D Mccullough, Bhanu Priya Ganesh

Faculty, Staff and Students Publications

BACKGROUND: Risk of stroke-related morbidity and mortality increases significantly with age. Aging is associated with chronic, low-grade inflammation, which is thought to contribute to the poorer outcomes after stroke seen in the elderly. Histamine (HA) is a major molecular mediator of inflammation, and mast cells residing in the gut are a primary source of histamine.

METHODS: Stroke was induced in male C57BL/6 J mice at 3 months (young) and 20 months (aged) of age. Role of histamine after stroke was examined using young (Yg) and aged (Ag) mice; mice underwent MCAO surgery and were euthanized at 6 h, 24 h, …

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 …

Proteolysis-Targeting Chimera (Protac) For Targeted Protein Degradation And Cancer Therapy, Xin Li, Yongcheng Song

Faculty, Staff and Students Publications

Proteolysis-targeting chimera (PROTAC) has been developed to be a useful technology for targeted protein degradation. A bifunctional PROTAC molecule consists of a ligand (mostly small-molecule inhibitor) of the protein of interest (POI) and a covalently linked ligand of an E3 ubiquitin ligase (E3). Upon binding to the POI, the PROTAC can recruit E3 for POI ubiquitination, which is subjected to proteasome-mediated degradation. PROTAC complements nucleic acid-based gene knockdown/out technologies for targeted protein reduction and could mimic pharmacological protein inhibition. To date, PROTACs targeting ~ 50 proteins, many of which are clinically validated drug targets, have been successfully developed with several …

A Goldenbraid Cloning System For Synthetic Biology In Social Amoebae, Peter Kundert, Alejandro Sarrion-Perdigones, Yezabel Gonzalez, Mariko Katoh-Kurasawa, Shigenori Hirose, Peter Lehmann, Koen J T Venken, Gad Shaulsky

Faculty, Staff and Students Publications

GoldenBraid is a rapid, modular, and robust cloning system used to assemble and combine genetic elements. Dictyostelium amoebae represent an intriguing synthetic biological chassis with tractable applications in development, chemotaxis, bacteria-host interactions, and allorecognition. We present GoldenBraid as a synthetic biological framework for Dictyostelium, including a library of 250 DNA parts and assemblies and a proof-of-concept strain that illustrates cAMP-chemotaxis with four fluorescent reporters coded by one plasmid.

Structure And Mechanism Of Human Diacylglycerol O-Acyltransferase 1, Lie Wang, Hongwu Qian, Yin Nian, Yimo Han, Zhenning Ren, Hanzhi Zhang, Liya Hu, B V Venkataram Prasad, Arthur Laganowsky, Nieng Yan, Ming Zhou

Faculty, Staff and Students Publications

Diacylglycerol O-acyltransferase-1 (DGAT1) synthesizes triacylglycerides and is required for dietary fat absorption and fat storage in humans1. DGAT1 belongs to the superfamily of membrane-bound O-acyltransferases (MBOAT) that are found in all kingdoms of life and involved in acylation of lipids and proteins2,3. It remains unclear how human DGAT1 (hDGAT1) or other mammalian members of the MBOAT family recognize their substrates and catalyze their reactions. The absence of three-dimensional structures also hampers rational targeting of hDGAT1 for therapeutic purposes. Here we present the structure of hDGAT1 in complex with a substrate oleoyl Coenzyme A solved …

Process Monitoring Of Moisture Content And Mass Transfer Rate In A Fluidised Bed With A Low Cost Inline Mems Nir Sensor, Claudio R Avila, Joan Ferré, Rodrigo Rocha De Oliveira, Anna De Juan, Wayne E Sinclair, Faiz M Mahdi, Ali Hassanpour, Timothy N Hunter, Richard A Bourne, Frans L Muller

Faculty, Staff and Students Publications

PURPOSE: The current trend for continuous drug product manufacturing requires new, affordable process analytical techniques (PAT) to ensure control of processing. This work evaluates whether property models based on spectral data from recent Fabry-Pérot Interferometer based NIR sensors can generate a high-resolution moisture signal suitable for process control.

METHODS: Spectral data and offline moisture content were recorded for 14 fluid bed dryer batches of pharmaceutical granules. A PLS moisture model was constructed resulting in a high resolution moisture signal, used to demonstrate (i) endpoint determination and (ii) evaluation of mass transfer performance.

RESULTS: The sensors appear robust with respect to …

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 …

Acetylation Of Histone H3k27 Signals The Transcriptional Elongation For Estrogen Receptor Alpha, Yujing Gao, Lijia Chen, Yali Han, Fangrui Wu, Wen-Si Yang, Zheng Zhang, Tong Huo, Yingmin Zhu, Chengtai Yu, Hong Kim, Mark Lee, Zhen Tang, Kevin Phillips, Bin He, Sung Yun Jung, Yongcheng Song, Bokai Zhu, Rui-Ming Xu, Qin Feng

Faculty, Staff and Students Publications

As approximately 70% of human breast tumors are estrogen receptor α (ERα)-positive, estrogen and ERα play essential roles in breast cancer development. By interrupting the ERα signaling pathway, endocrine therapy has been proven to be an effective therapeutic strategy. In this study, we identified a mechanism by which Transcription Start Site (TSS)-associated histone H3K27 acetylation signals the Super Elongation Complex (SEC) to regulate transcriptional elongation of the ESR1 (ERα) gene. SEC interacts with H3K27ac on ESR1 TSS through its scaffold protein AFF4. Depletion of AFF4 by siRNA or CRISPR/Cas9 dramatically reduces expression of ESR1 and its target genes, consequently inhibiting …

Principles Of Rna Processing From Analysis Of Enhanced Clip Maps For 150 Rna Binding Proteins, Eric L Van Nostrand, Gabriel A Pratt, Brian A Yee, Emily C Wheeler, Steven M Blue, Jasmine Mueller, Samuel S Park, Keri E Garcia, Chelsea Gelboin-Burkhart, Thai B Nguyen, Ines Rabano, Rebecca Stanton, Balaji Sundararaman, Ruth Wang, Xiang-Dong Fu, Brenton R Graveley, Gene W Yeo

Faculty, Staff and Students Publications

BACKGROUND: A critical step in uncovering rules of RNA processing is to study the in vivo regulatory networks of RNA binding proteins (RBPs). Crosslinking and immunoprecipitation (CLIP) methods enable mapping RBP targets transcriptome-wide, but methodological differences present challenges to large-scale analysis across datasets. The development of enhanced CLIP (eCLIP) enabled the mapping of targets for 150 RBPs in K562 and HepG2, creating a unique resource of RBP interactomes profiled with a standardized methodology in the same cell types.

RESULTS: Our analysis of 223 eCLIP datasets reveals a range of binding modalities, including highly resolved positioning around splicing signals and mRNA …

Phosphoinositides In Retinal Function And Disease, Theodore G Wensel

Faculty, Staff and Students Publications

Phosphatidylinositol and its phosphorylated derivatives, the phosphoinositides, play many important roles in all eukaryotic cells. These include modulation of physical properties of membranes, activation or inhibition of membrane-associated proteins, recruitment of peripheral membrane proteins that act as effectors, and control of membrane trafficking. They also serve as precursors for important second messengers, inositol (1,4,5) trisphosphate and diacylglycerol. Animal models and human diseases involving defects in phosphoinositide regulatory pathways have revealed their importance for function in the mammalian retina and retinal pigmented epithelium. New technologies for localizing, measuring and genetically manipulating them are revealing new information about their importance for the …

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, …

27 Å Cryo-Em Structure Of Rotavirus Core Protein Vp3, A Unique Capping Machine With A Helicase Activity, Dilip Kumar, Xinzhe Yu, Sue E Crawford, Rodolfo Moreno, Joanita Jakana, Banumathi Sankaran, Ramakrishnan Anish, Soni Kaundal, Liya Hu, Mary K Estes, Zhao Wang, B V Venkataram Prasad

Faculty, Staff and Students Publications

In many viruses, including rotavirus (RV), the major pathogen of infantile gastroenteritis, capping of viral messenger RNAs is a pivotal step for efficient translation of the viral genome. In RV, VP3 caps the nascent transcripts synthesized from the genomic dsRNA segments by the RV polymerase VP1 within the particle core. Here, from cryo-electron microscopy, x-ray crystallography, and biochemical analyses, we show that VP3 forms a stable tetrameric assembly with each subunit having a modular domain organization, which uniquely integrates five distinct enzymatic steps required for capping the transcripts. In addition to the previously known guanylyl- and methyltransferase activities, we show …

Provider Attitudes And Practice Patterns For Direct-Acting Antiviral Therapy For Patients With Hepatocellular Carcinoma, Nicole E Rich, Ju Dong Yang, Ponni V Perumalswami, Naim Alkhouri, Whitney Jackson, Neehar D Parikh, Neil Mehta, Reena Salgia, Andres Duarte-Rojo, Laura Kulik, Mina Rakoski, Adnan Said, Omobonike Oloruntoba, George N Ioannou, Maarouf A Hoteit, Andrew M Moon, Amol S Rangnekar, Sheila L Eswaran, Elizabeth Zheng, Janice H Jou, James Hanje, Anjana Pillai, Ruben Hernaez, Robert Wong, Steven Scaglione, Hrishikesh Samant, Devika Kapuria, Shaun Chandna, Russell Rosenblatt, Veeral Ajmera, Catherine T Frenette, Sanjaya K Satapathy, Parvez Mantry, Prasun Jalal, Binu V John, Oren K Fix, Michael Leise, Christina C Lindenmeyer, Avegail Flores, Nayan Patel, Z Gordon Jiang, Nyan Latt, Renumathy Dhanasekaran, Mobolaji Odewole, Sofia Kagan, Jorge A Marrero, Amit G Singal

Faculty, Staff and Students Publications

BACKGROUND & AIMS: Direct-acting antivirals (DAAs) are effective against hepatitis C virus and sustained virologic response is associated with reduced incidence of hepatocellular carcinoma (HCC). However, there is controversy over the use of DAAs in patients with active or treated HCC and uncertainty about optimal management of these patients. We aimed to characterize attitudes and practice patterns of hepatology practitioners in the United States regarding the use of DAAs in patients with HCC.

METHODS: We conducted a survey of hepatology providers at 47 tertiary care centers in 25 states. Surveys were sent to 476 providers and we received 279 responses …

Defining A Taxonomy Of Intracranial Hypertension: Is Icp More Than Just A Number?, W Andrew Kofke, Swarna Rajagopalan, Diana Ayubcha, Ramani Balu, Jovany Cruz-Navarro, Panumart Manatpon, Elizabeth Mahanna-Gabrielli

Faculty, Staff and Students Publications

Intracranial pressure (ICP) monitoring and control is a cornerstone of neuroanesthesia and neurocritical care. However, because elevated ICP can be due to multiple pathophysiological processes, its interpretation is not straightforward. We propose a formal taxonomy of intracranial hypertension, which defines ICP elevations into 3 major pathophysiological subsets: increased cerebral blood volume, masses and edema, and hydrocephalus. (1) Increased cerebral blood volume increases ICP and arises secondary to arterial or venous hypervolemia. Arterial hypervolemia is produced by autoregulated or dysregulated vasodilation, both of which are importantly and disparately affected by systemic blood pressure. Dysregulated vasodilation tends to be worsened by arterial …

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 …

The Sineb1 Element In The Long Non-Coding Rna Malat1 Is Necessary For Tdp-43 Proteostasis, Tuan M Nguyen, Elena B Kabotyanski, Lucas C Reineke, Jiaofang Shao, Feng Xiong, Joo-Hyung Lee, Julien Dubrulle, Hannah Johnson, Fabio Stossi, Phoebe S Tsoi, Kyoung-Jae Choi, Alexander G Ellis, Na Zhao, Jin Cao, Oluwatoyosi Adewunmi, Josephine C Ferreon, Allan Chris M Ferreon, Joel R Neilson, Michael A Mancini, Xi Chen, Jongchan Kim, Li Ma, Wenbo Li, Jeffrey M Rosen

Faculty, Staff and Students Publications

Transposable elements (TEs) comprise a large proportion of long non-coding RNAs (lncRNAs). Here, we employed CRISPR to delete a short interspersed nuclear element (SINE) in Malat1, a cancer-associated lncRNA, to investigate its significance in cellular physiology. We show that Malat1 with a SINE deletion forms diffuse nuclear speckles and is frequently translocated to the cytoplasm. SINE-deleted cells exhibit an activated unfolded protein response and PKR and markedly increased DNA damage and apoptosis caused by dysregulation of TDP-43 localization and formation of cytotoxic inclusions. TDP-43 binds stronger to Malat1 without the SINE and is likely 'hijacked' by cytoplasmic Malat1 to the …

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 …

The Struggling Infectious Diseases Fellow: Remediation Challenges And Opportunities, Michael T Melia, Armando Paez, Gail Reid, Lisa M Chirch, Vera P Luther, Brian G Blackburn, Federico Perez, Emily Abdoler, Daniel R Kaul, Susan Rehm, Nada Harik, Alice Barsoumian, Anna K Person, Heather Yun, J David Beckham, Susan Boruchoff, Paloma F Cariello, James B Cutrell, Christopher J Graber, Dong Heun Lee, Eileen Maziarz, Molly L Paras, Raymund R Razonable, Roseanne Ressner, Anne Chen, Brian Chow, Gerome Escota, Erica Herc, Andrew Johnson, Ryan C Maves, Obinna Nnedu, Heather Clauss, Prathit Kulkarni, Paul S Pottinger, Jose A Serpa, Tanaya Bhowmick, Marvin Bittner, Darcy Wooten, Beata Casanas, Rachel Shnekendorf, Emily A Blumberg

Faculty, Staff and Students Publications

Remediation of struggling learners is a challenge faced by all educators. In recognition of this reality, and in light of contemporary challenges facing infectious diseases (ID) fellowship program directors, the Infectious Diseases Society of America Training Program Directors' Committee focused the 2018 National Fellowship Program Directors' Meeting at IDWeek on "Remediation of the Struggling Fellow." Small group discussions addressed 7 core topics, including feedback and evaluations, performance management and remediation, knowledge deficits, fellow well-being, efficiency and time management, teaching skills, and career development. This manuscript synthesizes those discussions around a competency-based framework to provide program directors and other educators with …

Probable African Tick Bite Fever In The United States, Kami Lowery, Theodore Rosen

Faculty, Staff and Students Publications

African tick bite fever (ATBF) is a tick-borne rickettsial disease most often observed in North American and European tourists returning home from the southern portion of Africa. Ticks infected with Rickettsia africae transmit this parasitic bacterium to humans, who subsequently develop an influenza-like illness, one or more inoculation eschars, and in some cases, a cutaneous rash. Because ATBF often presents with non-specific symptoms that suggest other infectious diseases, establishing the diagnosis may be difficult. Confirmatory assays, including serology and nucleic acid amplification, may take weeks to return and cannot help with acute treatment decisions. We present a case of a …

Homogeneous And Functional Group Tolerant Ring-Closing Metathesis For Dna-Encoded Chemical Libraries, Olivier B C Monty, Pranavanand Nyshadham, Kurt M Bohren, Murugesan Palaniappan, Martin M Matzuk, Damian W Young, Nicholas Simmons

Faculty, Staff and Students Publications

Reaction heterogeneity, poor pH control, and catalyst decomposition in the ring-closing metathesis (RCM) of DNA–chemical conjugates lead to poor yields of the cyclized products. Herein we address these issues with a RCM reaction system that includes a novel aqueous solvent combination to enable reaction homogeneity, an acidic buffer system which masks traditionally problematic functional groups, and a decomposition-resistant catalyst which maximizes conversion to the cyclized product. Additionally, we provide a systematic study of the substrate scope of the on-DNA RCM reaction, a demonstration of its applicability to a single-substrate DNA-encoded chemical library that includes sequencing analysis, and the first successful …

A Broad-Spectrum Antiviral Molecule, Ql47, Selectively Inhibits Eukaryotic Translation, Mélissanne De Wispelaere, Margot Carocci, Dominique J Burri, William J Neidermyer, Calla M Olson, Imme Roggenbach, Yanke Liang, Jinhua Wang, Sean P J Whelan, Nathanael S Gray, Priscilla L Yang

Faculty, Staff and Students Publications

Small-molecule inhibitors of translation are critical tools to study the molecular mechanisms of protein synthesis. In this study, we sought to characterize how QL47, a host-targeted, small-molecule antiviral agent, inhibits steady-state viral protein expression. We demonstrate that this small molecule broadly inhibits both viral and host protein synthesis and targets a translation step specific to eukaryotic cells. We show that QL47 inhibits protein neosynthesis initiated by both canonical cap-driven and noncanonical initiation strategies, most likely by targeting an early step in translation elongation. Our findings thus establish QL47 as a new small-molecule inhibitor that can be utilized to probe the …

A Retrospective Matched-Cohort Study Of 3994 Lower Extremity Wounds Of Multiple Etiologies Across 644 Institutions Comparing A Bioactive Human Skin Allograft, Theraskin, Plus Standard Of Care, To Standard Of Care Alone, Geoff C Gurtner, Aimee D Garcia, Katie Bakewell, Jason B Alarcon

Faculty, Staff and Students Publications

Most chronic wounds are related to comorbidities, for which no clinical trials are performed. This retrospective propensity matched-cohort study examined data from 2 074 000 lower extremity wounds across 644 institutions to determine the effectiveness of TheraSkin plus standard of care (SOC; n = 1997) versus SOC alone (n = 1997). Multivariate modelling comparing outcomes such as healing rates, percent area reductions (PARs), amputations, recidivism, treatment completion, and medical transfers were evaluated. A higher proportion of wounds in the treatment group compared with the controls were more likely to close (68.3% versus 60.3%), particularly wounds with exposed structures (64% versus …

Losartan Rescues Inflammation-Related Mucociliary Dysfunction In Relevant Models Of Cystic Fibrosis, Michael D Kim, Nathalie Baumlin, Makoto Yoshida, Deepika Polineni, Sebastian F Salathe, Joseph K David, Charles A Peloquin, Adam Wanner, John S Dennis, Juliette Sailland, Philip Whitney, Frank T Horrigan, Juan R Sabater, William M Abraham, Matthias Salathe

Faculty, Staff and Students Publications

Rationale: Despite therapeutic progress in treating cystic fibrosis (CF) airway disease, airway inflammation with associated mucociliary dysfunction remains largely unaddressed. Inflammation reduces the activity of apically expressed large-conductance Ca²⁺-activated and voltage-dependent K⁺ (BK) channels, critical for mucociliary function in the absence of CFTR (CF transmembrane conductance regulator).

Objectives: To test losartan as an antiinflammatory therapy in CF using CF human bronchial epithelial cells and an ovine model of CF-like airway disease.

Methods: Losartan’s antiinflammatory effectiveness to rescue BK activity and thus mucociliary function was tested in vitro using primary, fully redifferentiated human airway epithelial cells homozygous for …