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Respective Contributions Of Single And Compound Granule Fusion To Secretion By Activated Platelets, Anita Eckly, Jean-Yves Rinckel, Fabienne Proamer, Neslihan Ulas, Smita Joshi, Sidney W. Whiteheart, Christian Gachet

Molecular and Cellular Biochemistry Faculty Publications

Although granule secretion is pivotal in many platelet responses, the fusion routes of α and δ granule release remain uncertain. We used a 3D reconstruction approach based on electron microscopy to visualize the spatial organization of granules in unstimulated and activated platelets. Two modes of exocytosis were identified: a single mode that leads to release of the contents of individual granules and a compound mode that leads to the formation of granule-to-granule fusion, resulting in the formation of large multigranular compartments. Both modes occur during the course of platelet secretion. Single fusion events are more visible at lower levels of …

Genome Of The Asian Longhorned Beetle (Anoplophora Glabripennis), A Globally Significant Invasive Species, Reveals Key Functional And Evolutionary Innovations At The Beetle-Plant Interface, Duane D. Mckenna, Erin D. Scully, Yannick Pauchet, Kelli Hoover, Roy Kirsch, Scott M. Geib, Robert F. Mitchell, Robert M. Waterhouse, Seung-Joon Ahn, Deanna Arsala, Joshua B. Benoit, Heath Blackmon, Tiffany Bledsoe, Julia H. Bowsher, André Busch, Bernarda Calla, Hsu Chao, Anna K. Childers, Christopher Childers, Dave J. Clarke, Lorna Cohen, Jeffery P. Demuth, Huyen Dinh, Harshavardhan Doddapaneni, Amanda Dolan, Jian J. Duan, Shannon Dugan, Markus Friedrich, Karl M. Glastad, Michael A. D. Goodisman, Stephanie Haddad, Yi Han, Daniel S. T. Hughes, Panagiotis Ioannidis, J. Spencer Johnston, Jeffery W. Jones, Leslie A. Kuhn, David R. Lance, Chien-Yueh Lee, Sandra L. Lee, Han Lin, Jeremy A. Lynch, Armin P. Moczek, Shwetha C. Murali, Donna M. Muzny, David R. Nelson, Subba R. Palli, Kristen A. Panfilio, Dan Pers, Monica F. Poelchau, Honghu Quan, Jiaxin Qu, Ann M. Ray, Joseph P. Rinehart, Hugh M. Robertson, Richard Roehrdanz, Andrew J. Rosendale, Seunggwan Shin, Christian Silva, Alex S. Torson, Iris M. Vargas Jentzsch, John H. Werren, Kim C. Worley, George Yocum, Evgeny M. Zdobnov, Richard A. Gibbs, Stephen Richards

Entomology Faculty Publications

Background: Relatively little is known about the genomic basis and evolution of wood-feeding in beetles. We undertook genome sequencing and annotation, gene expression assays, studies of plant cell wall degrading enzymes, and other functional and comparative studies of the Asian longhorned beetle, Anoplophora glabripennis, a globally significant invasive species capable of inflicting severe feeding damage on many important tree species. Complementary studies of genes encoding enzymes involved in digestion of woody plant tissues or detoxification of plant allelochemicals were undertaken with the genomes of 14 additional insects, including the newly sequenced emerald ash borer and bull-headed dung beetle.

Results: …

Pleckstrin Homology (Ph) Domain Leucine-Rich Repeat Protein Phosphatase Controls Cell Polarity By Negatively Regulating The Activity Of Atypical Protein Kinase C, Xiaopeng Xiong, Xin Li, Yang-An Wen, Tianyan Gao

Markey Cancer Center Faculty Publications

The proper establishment of epithelial polarity allows cells to sense and respond to signals that arise from the microenvironment in a spatiotemporally controlled manner. Atypical PKCs (aPKCs) are implicated as key regulators of epithelial polarity. However, the molecular mechanism underlying the negative regulation of aPKCs remains largely unknown. In this study, we demonstrated that PH domain leucine-rich repeat protein phosphatase (PHLPP), a novel family of Ser/Thr protein phosphatases, plays an important role in regulating epithelial polarity by controlling the phosphorylation of both aPKC isoforms. Altered expression of PHLPP1 or PHLPP2 disrupted polarization of Caco2 cells grown in 3D cell cultures …

Optical Tracer Size Differences Allow Quantitation Of Active Pumping Rate Versus Stokes–Einstein Diffusion In Lymphatic Transport, Alisha V. Dsouza, Kayla Marra, Jason R. Gunn, Kimberley S. Samkoe, Brian W. Pogue

Dartmouth Scholarship

Lymphatic uptake of interstitially administered agents occurs by passive convective–diffusive inflow driven by interstitial concentration and pressure, while the downstream lymphatic transport is facilitated by active propulsive contractions of lymphatic vessel walls. Near-infrared fluorescence imaging in mice was used to measure these central components of lymphatic transport for the first time, using two different-sized molecules––methylene blue (MB) and fluorescence-labeled antibody immunoglobulin G (IgG)-IRDye 680RD. This work confirms the hypothesis that lymphatic passive inflow and active propulsion rates can be separated based upon the relative differences in Stokes–Einstein diffusion coefficient. This coefficient specifically affects the passive-diffusive uptake when the interstitial volume …

Beryllium Nitrate Inhibits Fibroblast Migration To Disrupt Epimorphic Regeneration, Adam B. Cook, Ashley W. Seifert

Biology Faculty Publications

Epimorphic regeneration proceeds with or without formation of a blastema, as observed for the limb and skin, respectively. Inhibition of epimorphic regeneration provides a means to interrogate the cellular and molecular mechanisms that regulate it. In this study, we show that exposing amputated limbs to beryllium nitrate disrupts blastema formation and causes severe patterning defects in limb regeneration. In contrast, exposing full-thickness skin wounds to beryllium only causes a delay in skin regeneration. By transplanting full-thickness skin from ubiquitous GFP-expressing axolotls to wild-type hosts, we demonstrate that beryllium inhibits fibroblast migration during limb and skin regeneration in vivo. Moreover, …

Change In Regulation Is Necessary For Genetically Engineered Mosquitoes, Insung Hwang

Michigan Journal of Environmental & Administrative Law

Millions of genetically engineered (GE) mosquitoes could soon be released in Key West, Florida as an effort to eradicate wild mosquitoes that are transmitters of diseases such as malaria, dengue, and chikungunya. Both international and domestic regulations fail to provide effective regulatory schemes that can facilitate the application of this technology while ensuring all safety and environmental aspects are properly addressed. The Food and Drug Administration’s assertion of jurisdiction is based on its assessment that the GE mosquitoes are “animal drugs” under the Federal Food, Drug, and Cosmetic Act. This is especially troublesome because the end goal of using these …

Stress-Induced Reinstatement Of Nicotine Preference Requires Dynorphin/Kappa Opioid Activity In The Basolateral Amygdala, Stephanie K. Nygard, Nicholas J. Hourguettes, Gabe G. Sobczak, William A. Carlezon, Michael R. Bruchas

Open Access Publications

UNLABELLED: The dynorphin (DYN)/kappa-opioid receptor (KOR) system plays a conserved role in stress-induced reinstatement of drug seeking for prototypical substances of abuse. Due to nicotine's high propensity for stress-induced relapse, we hypothesized that stress would induce reinstatement of nicotine seeking-like behavior in a KOR-dependent manner. Using a conditioned place preference (CPP) reinstatement procedure in mice, we show that both foot-shock stress and the pharmacological stressor yohimbine (2 mg/kg, i.p.) induce reinstatement of nicotine CPP in a norbinaltorphimine (norBNI, a KOR antagonist)-sensitive manner, indicating that KOR activity is necessary for stress-induced nicotine CPP reinstatement. After reinstatement testing, we visualized robust c-fos …

Mitochondrial Akt Regulation Of Hypoxic Tumor Reprogramming., Young Chan Chae, Valentina Vaira, M. Cecilia Caino, Hsin-Yao Tang, Jae Ho Seo, Andrew V. Kossenkov, Luisa Ottobrini, Cristina Martelli, Giovanni Lucignani, Irene Bertolini, Marco Locatelli, Kelly G. Bryant, Jagadish C. Ghosh, Sofia Lisanti, Bonsu Ku, Silvano Bosari, Lucia R. Languino, David W. Speicher, Dario C. Altieri

Department of Cancer Biology Faculty Papers

Hypoxia is a universal driver of aggressive tumor behavior, but the underlying mechanisms are not completely understood. Using a phosphoproteomics screen, we now show that active Akt accumulates in the mitochondria during hypoxia and phosphorylates pyruvate dehydrogenase kinase 1 (PDK1) on Thr346 to inactivate the pyruvate dehydrogenase complex. In turn, this pathway switches tumor metabolism toward glycolysis, antagonizes apoptosis and autophagy, dampens oxidative stress, and maintains tumor cell proliferation in the face of severe hypoxia. Mitochondrial Akt-PDK1 signaling correlates with unfavorable prognostic markers and shorter survival in glioma patients and may provide an "actionable" therapeutic target in cancer.

Are Animals Persons?, Mark Rowlands

Animal Sentience

It is orthodox to suppose that very few, if any, nonhuman animals are persons. The category “person” is restricted to self-aware creatures: humans (above a certain age) and possibly some of the great apes and cetaceans. I argue that this orthodoxy should be rejected, because it rests on a mistaken conception of the kind of self-awareness relevant to personhood. Replacing this with a sense of self-awareness that is relevant requires us to accept that personhood is much more widely distributed through the animal kingdom.

The Salicylic Acid-Mediated Release Of Plant Volatiles Affects The Host Choice Of Bemisia Tabaci, Xiaobin Shi, Gong Chen, Lixia Tian, Zhengke Peng, Wen Xie, Qingjun Wu, Shaoli Wang, Xuguo Zhou, Youjun Zhang

Entomology Faculty Publications

The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) causes serious crop losses worldwide by transmitting viruses. We have previously shown that salicylic acid (SA)-related plant defenses directly affect whiteflies. In this study, we applied exogenous SA to tomato plants in order to investigate the interaction between SA-induced plant volatiles and nonviruliferous B. tabaci B and Q or B- and Q-carrying tomato yellow leaf curl virus (TYLCV). The results showed that exogenous SA caused plants to repel nonviruliferous whiteflies, but the effect was reduced when the SA concentration was low and when the whiteflies were viruliferous. Exogenous SA increased the number and …

Using Diffusion Tractography To Predict Cortical Connection Strength And Distance: A Quantitative Comparison With Tracers In The Monkey, Chad J. Donahue, Stamatios N. Sotiropoulos, Saad Jbabdi, Moises Hernandez-Fernandez, Timothy E. Behrens, Tim B. Dyrby, Timothy Coalson, Henry Kennedy, Kenneth Knoblauch, David C. Van Essen, Matthew F. Glasser

Open Access Publications

UNLABELLED: Tractography based on diffusion MRI offers the promise of characterizing many aspects of long-distance connectivity in the brain, but requires quantitative validation to assess its strengths and limitations. Here, we evaluate tractography's ability to estimate the presence and strength of connections between areas of macaque neocortex by comparing its results with published data from retrograde tracer injections. Probabilistic tractography was performed on high-quality postmortem diffusion imaging scans from two Old World monkey brains. Tractography connection weights were estimated using a fractional scaling method based on normalized streamline density. We found a correlation between log-transformed tractography and tracer connection weights …

Staphylococcus Aureus Coordinates Leukocidin Expression And Pathogenesis By Sensing Metabolic Fluxes Via Rpirc, Divya Balasubramanian, Elizabeth A Ohneck, Jessica Chapman, Andy Weiss, Min Kyung Kim, Tamara Reyes-Robles, Judy Zhong, Lindsey N. Shaw, Desmond S. Lun, Beatrix Ueberheide, Bo Shopsin, Victor J Torres

Molecular Biosciences Faculty Publications

Staphylococcus aureus is a formidable human pathogen that uses secreted cytolytic factors to injure immune cells and promote infection of its host. Of these proteins, the bicomponent family of pore-forming leukocidins play critical roles in S. aureus pathogenesis. The regulatory mechanisms governing the expression of these toxins are incompletely defined. In this work, we performed a screen to identify transcriptional regulators involved in leukocidin expression in S. aureus strain USA300. We discovered that a metabolic sensor-regulator, RpiRc, is a potent and selective repressor of two leukocidins, LukED and LukSF-PV. Whole-genome transcriptomics, S. aureus exoprotein proteomics, and metabolomic analyses revealed that …

Identification Of Ecdysone Hormone Receptor Agonists As A Therapeutic Approach For Treating Filarial Infections, Amruta S Mhashilkar, Sai L Vankayala, Canhui Liu, Fiona Kearns, Priyanka Mehrotra, George Tzertzinis, Subba R Palli, H. Lee Woodcock Iii, Thomas R Unnasch

Chemistry Faculty Publications

BACKGROUND: A homologue of the ecdysone receptor has previously been identified in human filarial parasites. As the ecdysone receptor is not found in vertebrates, it and the regulatory pathways it controls represent attractive potential chemotherapeutic targets.

METHODOLOGY/ PRINCIPAL FINDINGS: Administration of 20-hydroxyecdysone to gerbils infected with B. malayi infective larvae disrupted their development to adult stage parasites. A stable mammalian cell line was created incorporating the B. malayi ecdysone receptor ligand-binding domain, its heterodimer partner and a secreted luciferase reporter in HEK293 cells. This was employed to screen a series of ecdysone agonist, identifying seven agonists active at sub-micromolar concentrations. …

Single-Cell Transcriptional Analysis Of Normal, Aberrant, And Malignant Hematopoiesis In Zebrafish, Finola E. Moore, Elaine G. Garcia, Riadh Lobbardi, Esha Jain, Qin Tang, John C. Moore, Mauricio Cortes, Aleksey Molodtsov, Melissa Kasheta, Christina C. Luo, Amaris J. Garcia, Ravi Mylvaganam, Jeffrey A. Yoder, Jessica S. Blackburn, Ruslan I. Sadreyev, Craig J. Ceol, Trista E. North, David M. Langenau

Molecular and Cellular Biochemistry Faculty Publications

Hematopoiesis culminates in the production of functionally heterogeneous blood cell types. In zebrafish, the lack of cell surface antibodies has compelled researchers to use fluorescent transgenic reporter lines to label specific blood cell fractions. However, these approaches are limited by the availability of transgenic lines and fluorescent protein combinations that can be distinguished. Here, we have transcriptionally profiled single hematopoietic cells from zebrafish to define erythroid, myeloid, B, and T cell lineages. We also used our approach to identify hematopoietic stem and progenitor cells and a novel NK-lysin 4⁺ cell type, representing a putative cytotoxic T/NK cell. Our platform …

Capturing The Phylogeny Of Holometabola With Mitochondrial Genome Data And Bayesian Site-Heterogeneous Mixture Models, Fan Song, Hu Li, Pei Jiang, Xuguo Zhou, Jinpeng Liu, Changhai Sun, Alfried P. Vogler, Wanzhi Cai

Entomology Faculty Publications

After decades of debate, a mostly satisfactory resolution of relationships among the 11 recognized holometabolan orders of insects has been reached based on nuclear genes, resolving one of the most substantial branches of the tree-of-life, but the relationships are still not well established with mitochondrial genome data. The main reasons have been the absence of sufficient data in several orders and lack of appropriate phylogenetic methods that avoid the systematic errors from compositional and mutational biases in insect mitochondrial genomes. In this study, we assembled the richest taxon sampling of Holometabola to date (199 species in 11 orders), and analyzed …

A One Health Message About Bats Increases Intentions To Follow Public Health Guidance On Bat Rabies, Hang Lu, Katherine A. Mccomas, Danielle E. Buttke, Sungjong Roh, Margaret A. Wild

Research Collection Lee Kong Chian School Of Business

Since 1960, bat rabies variants have become the greatest source of human rabies deaths in the United States. Improving rabies awareness and preventing human exposure to rabid bats remains a national public health priority today. Concurrently, conservation of bats and the ecosystem benefits they provide is of increasing importance due to declining populations of many bat species. This study used a visitor-intercept experiment (N = 521) in two U.S. national parks where human and bat interactions occur on an occasional basis to examine the relative persuasiveness of four messages differing in the provision of benefit and uncertainty information on intentions …

Agonist-Mediated Activation Of Sting Induces Apoptosis In Malignant B Cells, Chih-Hang Anthony Tang, Joseph A. Zundell, Sujeewa Ranatunga, Cindy Lin, Yulia Nefedova, Juan R. Del Valle, Chih-Chi Andrew Hu

Chemistry Faculty Publications

Endoplasmic reticulum (ER) stress responses through the IRE-1/XBP-1 pathway are required for the function of STING (TMEM173), an ER-resident transmembrane protein critical for cytoplasmic DNA sensing, IFN production, and cancer control. Here we show that the IRE-1/XBP-1 pathway functions downstream of STING and that STING agonists selectively trigger mitochondria-mediated apoptosis in normal and malignant B cells. Upon stimulation, STING was degraded less efficiently in B cells, implying that prolonged activation of STING can lead to apoptosis. Transient activation of the IRE-1/XBP-1 pathway partially protected agonist-stimulated malignant B cells from undergoing apoptosis. In Eμ-TCL1 mice with chronic lymphocytic leukemia, injection of …

An In Vitro And In Vivo Investigation Of Bivalent Ligands That Display Preferential Binding And Functional Activity For Different Melanocortin Receptor Homodimers, Cody J Lensing, Katie T Freeman, Sathya M Schnell, Danielle N Adank, Robert Charles Speth, Carrie Haskell-Luevano

Faculty Articles

Pharmacological probes for the melanocortin receptors have been utilized for studying various disease states including cancer, sexual function disorders, Alzheimer's disease, social disorders, cachexia, and obesity. This study focused on the design and synthesis of bivalent ligands to target melanocortin receptor homodimers. Lead ligands increased binding affinity by 14- to 25-fold and increased cAMP signaling potency by 3- to 5-fold compared to their monovalent counterparts. Unexpectedly, different bivalent ligands showed preferences for particular melanocortin receptor subtypes depending on the linker that connected the binding scaffolds, suggesting structural differences between the various dimer subtypes. Homobivalent compound 12 possessed a functional profile …

Steroid Binding To Autotaxin Links Bile Salts And Lysophosphatidic Acid Signalling, Willem-Jan Keune, Jens Hausmann, Ruth Bolier, Dagmar Tolenaars, Andreas Kremer, Tatjana Heidebrecht, Robbie P. Joosten, Manjula Sunkara, Andrew J. Morris, Elisa Matas-Rico, Wouter H. Moolenaar, Ronald P. Oude Elferink, Anastassis Perrakis

Gill Heart & Vascular Institute Faculty Publications

Autotaxin (ATX) generates the lipid mediator lysophosphatidic acid (LPA). ATX-LPA signalling is involved in multiple biological and pathophysiological processes, including vasculogenesis, fibrosis, cholestatic pruritus and tumour progression. ATX has a tripartite active site, combining a hydrophilic groove, a hydrophobic lipid-binding pocket and a tunnel of unclear function. We present crystal structures of rat ATX bound to 7α-hydroxycholesterol and the bile salt tauroursodeoxycholate (TUDCA), showing how the tunnel selectively binds steroids. A structure of ATX simultaneously harbouring TUDCA in the tunnel and LPA in the pocket, together with kinetic analysis, reveals that bile salts act as partial non-competitive inhibitors …

Levodopa Therapy For Parkinson Disease: A Look Backward And Forward, Peter A. Lewitt, Stanley Fahn

Neurology Articles

Although levodopa is widely recognized as the most effective therapy for Parkinson disease (PD), its introduction 5 decades ago was preceded by several years of uncertainty and equivocal clinical results. The translation of basic neuroscience research by Arvid Carlsson and Oleh Hornykiewicz provided a logical pathway for treating PD with levodopa. Yet the pioneering clinicians who transformed PD therapeutics with this drug--among them Walther Birkmayer, Isamu Sano, Patrick McGeer, George Cotzias, Melvin Yahr, and others--faced many challenges in determining whether the concept and the method for replenishing deficient striatal dopamine was correct. This article reviews highlights in the early development …

Glycine N-Acyltransferase-Like 3 Is Responsible For Long-Chain N-Acylglycine Formation In N18Tg2 Cells, Kristen A Jeffries, Daniel R Dempsey, Emma K Farrell, Ryan L Anderson, Gabrielle J Garbade, Tatyana S Gurina, Imran Gruhonjic, Carly A Gunderson, David J Merkler

Chemistry Faculty Publications

Long-chain fatty acid amides are signaling lipids found in mammals and other organisms; however, details of the metabolic pathways for the N-acylglycines and primary fatty acid amides (PFAMs) have remained elusive. Heavy-labeled precursor and subtraction lipidomic experiments in mouse neuroblastoma N18TG2 cells, a model cell line for the study of fatty acid amide metabolism, establish the biosynthetic pathways for the N-acylglycines and the PFAMs. We provide evidence that the N-acylglycines are formed by a long-chain specific glycine-conjugating enzyme, glycine N-acyltransferase-like 3 (GLYATL3). siRNA knockdown of GLYATL3 in the N18TG2 cells resulted in a decrease in the levels of the N-acylglycines …

Correlation Of Maximal Inspiratory Pressure To Transdiaphragmatic Twitch Pressure In Intensive Care Unit Patients, Gerald S. Supinski, Philip M. Westgate, Leigh Ann Callahan

Internal Medicine Faculty Publications

Background: Respiratory muscle weakness contributes to respiratory failure in ICU patients. Unfortunately, assessment of weakness is difficult since the most objective test, transdiaphragmatic pressure in response to phrenic nerve stimulation (PdiTw), is difficult to perform. While most clinicians utilize maximum inspiratory pressure (Pimax) to assess strength, the relationship of this index to PdiTw has not been evaluated in a large ICU population. The purpose of the present study was to assess both PdiTw and Pimax in ICU patients to determine how these indices correlate with each other, what factors influence these indices, and how well these indices predict outcomes.

Methods: …

Equine Protozoal Myeloencephalitis: An Updated Consensus Statement With A Focus On Parasite Biology, Diagnosis, Treatment, And Prevention, S. M. Reed, M. Furr, Daniel K. Howe, A. L. Johnson, R. J. Mackay, J. K. Morrow, N. Pusterla, S. Witonsky

Veterinary Science Faculty Publications

Equine protozoal myeloencephalitis (EPM) remains an important neurologic disease of horses. There are no pathognomonic clinical signs for the disease. Affected horses can have focal or multifocal central nervous system (CNS) disease. EPM can be difficult to diagnose antemortem. It is caused by either of 2 parasites, Sarcocystis neurona and Neospora hughesi, with much less known about N. hughesi. Although risk factors such as transport stress and breed and age correlations have been identified, biologic factors such as genetic predispositions of individual animals, and parasite-specific factors such as strain differences in virulence, remain largely undetermined. This consensus statement …

Comparison Of Protein Phosphatase Inhibition Assay With Lc-Ms/Ms For Diagnosis Of Microcystin Toxicosis In Veterinary Cases, Caroline E. Moore, Jeanette Juan, Yanping Lin, Cynthia L. Gaskill, Birgit Puschner

Veterinary Diagnostic Laboratory Faculty Publications

Microcystins are acute hepatotoxins of increasing global concern in drinking and recreational waters and are a major health risk to humans and animals. Produced by cyanobacteria, microcystins inhibit serine/threonine protein phosphatase 1 (PP1). A cost-effective PP1 assay using p-nitrophenyl phosphate was developed to quickly assess water and rumen content samples. Significant inhibition was determined via a linear model, which compared increasing volumes of sample to the log-transformed ratio of the exposed rate over the control rate of PP1 activity. To test the usefulness of this model in diagnostic case investigations, samples from two veterinary cases were tested. In August …

Smn Protein Can Be Reliably Measured In Whole Blood With An Electrochemiluminescence (Ecl) Immunoassay: Implications For Clinical Trials, Phillip Zaworski, Katharine M. Von Herrmann, Shannon Taylor, Sara S. Sunshine, Kathleen Mccarthy, Nicole Risher, Tara Newcomb, Marla Weetall, Thomas W. Prior, Kathryn J. Swoboda, Karen S. Chen, Sergey Paushkin

Dartmouth Scholarship

Spinal muscular atrophy (SMA) is caused by defects in the survival motor neuron 1 (SMN1) gene that encodes survival motor neuron (SMN) protein. The majority of therapeutic approaches currently in clinical development for SMA aim to increase SMN protein expression and there is a need for sensitive methods able to quantify increases in SMN protein levels in accessible tissues. We have developed a sensitive electrochemiluminescence (ECL)-based immunoassay for measuring SMN protein in whole blood with a minimum volume requirement of 5μL. The SMN-ECL immunoassay enables accurate measurement of SMN in whole blood and other tissues. Using the assay, …

Myonuclear Transcription Is Responsive To Mechanical Load And Dna Content But Uncoupled From Cell Size During Hypertrophy, Tyler J. Kirby, Rooshil M. Patel, Timothy S. Mcclintock, Esther E. Dupont-Versteegden, Charlotte A. Peterson, John J. Mccarthy

Physiology Faculty Publications

Myofibers increase size and DNA content in response to a hypertrophic stimulus, thus providing a physiological model with which to study how these factors affect global transcription. Using 5-ethynyl uridine (EU) to metabolically label nascent RNA, we measured a sevenfold increase in myofiber transcription during early hypertrophy before a change in cell size and DNA content. The typical increase in myofiber DNA content observed at the later stage of hypertrophy was associated with a significant decrease in the percentage of EU-positive myonuclei; however, when DNA content was held constant by preventing myonuclear accretion via satellite cell depletion, both the number …

Genomic Characterization Of Patient-Derived Xenograft Models Established From Fine Needle Aspirate Biopsies Of A Primary Pancreatic Ductal Adenocarcinoma And From Patient-Matched Metastatic Sites, Robert J. Allaway, Dawn A. Fischer, Francine B. De Abreu, Timothy B. Gardner, Stuart R. Gordon, Richard J. Barth, Thomas A. Colacchio, Matthew Wood, Balint Z. Kacsoh, Stephanie J. Bouley

Dartmouth Scholarship

N-of-1 trials target actionable mutations, yet such approaches do not test genomically-informed therapies in patient tumor models prior to patient treatment. To address this, we developed patient-derived xenograft (PDX) models from fine needle aspiration (FNA) biopsies (FNA-PDX) obtained from primary pancreatic ductal adenocarcinoma (PDAC) at the time of diagnosis. Here, we characterize PDX models established from one primary and two metastatic sites of one patient. We identified an activating KRAS G12R mutation among other mutations in these models. In explant cells derived from these PDX tumor models with a KRAS G12R mutation, treatment with inhibitors of CDKs (including CDK9) reduced …

Similar Metabolic Rate-Temperature Relationships After Acclimation At Constant And Fluctuating Temperatures In Caterpillars Of A Sub-Antarctic Moth., Steven L Chown, Tanya M Haupt, Brent J Sinclair

Biology Publications

Temperature compensation in whole-animal metabolic rate is one of the responses thought, controversially, to characterize insects from low temperature environments. Temperature compensation may either involve a change in absolute values of metabolic rates or a change in the slope of the metabolic rate - temperature relationship. Moreover, assessments of compensation may be complicated by animal responses to fluctuating temperatures. Here we examined whole animal metabolic rates, at 0 °C, 5 °C, 10 °C and 15 °C, in caterpillars of the sub-Antarctic moth, Pringleophaga marioni Viette (Tineidae), following one week acclimations to 5 °C, 10 °C and 15 °C, and fluctuating …

Predator Diet And Trophic Position Modified With Altered Habitat Morphology, Alexander Tewfik, Susan S. Bell, Kevin S. Mccann, Kristina Morrow

Integrative Biology Faculty and Staff Publications

Empirical patterns that emerge from an examination of food webs over gradients of environmental variation can help to predict the implications of anthropogenic disturbance on ecosystems. This “dynamic food web approach” is rarely applied at the coastal margin where aquatic and terrestrial systems are coupled and human development activities are often concentrated. We propose a simple model of ghost crab (Ocypode quadrata) feeding that predicts changing dominant prey (Emerita talpoida, Talorchestia sp., Donax variablis) along a gradient of beach morphology and test this model using a suite of 16 beaches along the Florida, USA coast. …

Gap Junction Mediated Mirna Intercellular Transfer And Gene Regulation: A Novel Mechanism For Intercellular Genetic Communication, Liang Zong, Yan Zhu, Ruqiang Liang, Hong-Bo Zhao

Otolaryngology--Head & Neck Surgery Faculty Publications

Intercellular genetic communication is an essential requirement for coordination of cell proliferation and differentiation and has an important role in many cellular processes. Gap junction channels possess large pore allowing passage of ions and small molecules between cells. MicroRNAs (miRNAs) are small regulatory RNAs that can regulate gene expression broadly. Here, we report that miRNAs can pass through gap junction channels in a connexin-dependent manner. Connexin43 (Cx43) had higher permeability, whereas Cx30 showed little permeability to miRNAs. In the tested connexin cell lines, the permeability to miRNAs demonstrated: Cx43 > Cx26/30 > Cx26 > Cx31 > Cx30 = Cx-null. However, consistent with a uniform …