Digital Commons Network^™

The Dichotomy Of Memantine Treatment For Ischemic Stroke: Dose-Dependent Protective And Detrimental Effects., Melissa Trotman, Philipp Vermehren, Claire L. Gibson, Robert Fern

More Faculty of Health Research

Excitotoxicity is a major contributor to cell death during the acute phase of ischemic stroke but aggressive pharmacological targeting of excitotoxicity has failed clinically. Here we investigated whether pretreatment with low doses of memantine, within the range currently used and well tolerated for the treatment of Alzheimer's disease, produce a protective effect in stroke. A coculture preparation exposed to modeled ischemia showed cell death associated with rapid glutamate rises and cytotoxic Ca(2+) influx. Cell death was significantly enhanced in the presence of high memantine concentrations. However, low memantine concentrations significantly protected neurons and glia via excitotoxic cascade interruption. Mice were …

The Bioscience-Industrial Complex, Radical Materialist Aesthetics, And Interspecies Political Ecologies: The Unforeseen Posthuman Future In Mary Shelley's Frankenstein And Margaret Atwood's Maddaddam Trilogy, Sarah Sydney Lane

Graduate Student Theses, Dissertations, & Professional Papers

This project traces how Mary Shelley’s Frankenstein and Margaret Atwood’s MaddAddam Trilogy, science fiction novels from the Romantic and contemporary literary periods respectively, contest the problematic relationships between subjecthood, science, ecological health, and patriarchal, capitalist societies by crafting radical materialist alternatives to such a system and its dualistic and destructive interpersonal/interspecies relations. Through the theoretical framework of ecofeminism that recognizes the conceptual linkages between women and nature in Western systems of thought, as well as psychoanalytical feminist critiques of the masculinization of scientific epistemology, this project examines the developmental and ontological overlaps between literary “masculine” and “scientific” subjects socialized under …

De Novo Assembly Of The Chimpanzee Transcriptome From Nextgen Mrna Sequences, Mnirnal D. Maudhoo, Jacob D. Madison, Robert B. Norgren

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: Common chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) are the species most closely related to humans. For this reason, it is especially important to have complete and accurate chimpanzee nucleotide and protein sequences to understand how humans evolved their unique capabilities. We provide transcriptome data from four untransformed cell types derived from the reference Pan troglodytes, "Clint", to better annotate the chimpanzee genome and provide empirical validation for proposed gene models of this important species.

FINDINGS: RNA was extracted from primary cells cultured from four tissues: skin, adipose stroma, vascular smooth muscle and skeletal muscle. These four RNA samples …

Gentamicin Differentially Alters Cellular Metabolism Of Cochlear Hair Cells As Revealed By Nad(P)H Fluorescence Lifetime Imaging, Lyandysha V. Zholudeva, Kristina G. Ward, Michael G. Nichols, Heather Jensen Smith

Journal Articles: Eppley Institute

Aminoglycoside antibiotics are implicated as culprits of hearing loss in more than 120,000 individuals annually. Research has shown that the sensory cells, but not supporting cells, of the cochlea are readily damaged and/or lost after use of such antibiotics. High-frequency outer hair cells (OHCs) show a greater sensitivity to antibiotics than high- and low-frequency inner hair cells (IHCs). We hypothesize that variations in mitochondrial metabolism account for differences in susceptibility. Fluorescence lifetime microscopy was used to quantify changes in NAD(P)H in sensory and supporting cells from explanted murine cochleae exposed to mitochondrial uncouplers, inhibitors, and an ototoxic antibiotic, gentamicin (GM). …

Treatment Of Progressive Multiple Sclerosis: What Works, What Does Not, And What Is Needed., Anthony Feinstein, Jenny Freeman, Albert C. Lo

School of Health Professions

Disease-modifying drugs have mostly failed as treatments for progressive multiple sclerosis. Management of the disease therefore solely aims to minimise symptoms and, if possible, improve function. The degree to which this approach is based on empirical data derived from studies of progressive disease or whether treatment decisions are based on what is known about relapsing-remitting disease remains unclear. Symptoms rated as important by patients with multiple sclerosis include balance and mobility impairments, weakness, reduced cardiovascular fitness, ataxia, fatigue, bladder dysfunction, spasticity, pain, cognitive deficits, depression, and pseudobulbar affect; a comprehensive literature search shows a notable paucity of studies devoted solely …

Fish Sound Production In The Presence Of Harmful Algal Blooms In The Eastern Gulf Of Mexico, Carrie C. Wall, Chad Lembke, Chuanmin Hu, David A. Mann

Marine Science Faculty Publications

This paper presents the first known research to examine sound production by fishes during harmful algal blooms (HABs). Most fish sound production is species-specific and repetitive, enabling passive acoustic monitoring to identify the distribution and behavior of soniferous species. Autonomous gliders that collect passive acoustic data and environmental data concurrently can be used to establish the oceanographic conditions surrounding sound-producing organisms. Three passive acoustic glider missions were conducted off west-central Florida in October 2011, and September and October 2012. The deployment period for two missions was dictated by the presence of red tide events with the glider path specifically set …

Classification Of Current Anticancer Immunotherapies., Lorenzo Galluzzi, Erika Vacchelli, José-Manuel Bravo-San Pedro, Aitziber Buqué, Laura Senovilla, Elisa Elena Baracco, Norma Bloy, Francesca Castoldi, Jean-Pierre Abastado, Patrizia Agostinis, Ron N. Apte, Fernando Aranda, Maha Ayyoub, Philipp Beckhove, Jean-Yves Blay, Laura Bracci, Anne Caignard, Chiara Castelli, Federica Cavallo, Estaban Celis, Vincenzo Cerundolo, Aled Clayton, Mario P. Colombo, Lisa Coussens, Madhav V. Dhodapkar, Alexander M. Eggermont, Douglas T. Fearon, Wolf H. Fridman, Jitka Fučíková, Dmitry I. Gabrilovich, Jérôme Galon, Abhishek Garg, François Ghiringhelli, Giuseppe Giaccone, Eli Gilboa, Sacha Gnjatic, Axel Hoos, Anne Hosmalin, Dirk Jäger, Pawel Kalinski, Klas Kärre, Oliver Kepp, Rolf Kiessling, John M. Kirkwood, Eva Klein, Alexander Knuth, Claire E. Lewis, Roland Liblau, Michael T. Lotze, Enrico Lugli, Jean-Pierre Mach, Fabrizio Mattei, Domenico Mavilio, Ignacio Melero, Cornelis J. Melief, Elizabeth A. Mittendorf, Lorenzo Moretta, Adekunke Odunsi, Hideho Okada, Anna Karolina Palucka, Marcus E. Peter, Kenneth J. Pienta, Angel Porgador, George C. Prendergast, Gabriel A. Rabinovich, Nicholas P. Restifo, Naiyer Rizvi, Catherine Sautès-Fridman, Hans Schreiber, Barbara Seliger, Hiroshi Shiku, Bruno Silva-Santos, Mark J. Smyth, Daniel E. Speiser, Radek Spisek, Pramod K. Srivastava, James E. Talmadge, Eric Tartour, Sjoerd H. Van Der Burg, Benoît J. Van Den Eynde, Richard Vile, Hermann Wagner, Jeffrey S. Weber, Theresa L. Whiteside, Jedd D. Wolchok, Laurence Zitvogel, Weiping Zou, Guido Kroemer

Journal Articles: Pathology and Microbiology

During the past decades, anticancer immunotherapy has evolved from a promising therapeutic option to a robust clinical reality. Many immunotherapeutic regimens are now approved by the US Food and Drug Administration and the European Medicines Agency for use in cancer patients, and many others are being investigated as standalone therapeutic interventions or combined with conventional treatments in clinical studies. Immunotherapies may be subdivided into "passive" and "active" based on their ability to engage the host immune system against cancer. Since the anticancer activity of most passive immunotherapeutics (including tumor-targeting monoclonal antibodies) also relies on the host immune system, this classification …

Functional And Developmental Identification Of A Molecular Subtype Of Brain Serotonergic Neuron Specialized To Regulate Breathing Dynamics, Rachael D. Brust, Andrea E. Corcoran, George B. Richerson, Eugene Nattie, Susan M. Dymecki

Dartmouth Scholarship

Serotonergic neurons modulate behavioral and physiological responses from aggression and anxiety to breathing and thermoregulation. Disorders involving serotonin (5HT) dysregulation are commensurately heterogeneous and numerous. We hypothesized that this breadth in functionality derives in part from a developmentally determined substructure of distinct subtypes of 5HT neurons each specialized to modulate specific behaviors. By manipulating developmentally defined subgroups one by one chemogenetically, we find that the Egr2-Pet1 subgroup is specialized to drive increased ventilation in response to carbon dioxide elevation and acidosis. Furthermore, this subtype exhibits intrinsic chemosensitivity and modality-specific projections-increasing firing during hypercapnic acidosis and selectively projecting to respiratory chemosensory …

A New Cecal Slurry Preparation Protocol With Improved Long-Term Reproducibility For Animal Models Of Sepsis, Marlene E. Starr, Allison M. Steele, Mizuki Saito, Bill J. Hacker, B. Mark Evers, Hiroshi Saito

Surgery Faculty Publications

Sepsis, a life-threatening systemic inflammatory response syndrome induced by infection, is widely studied using laboratory animal models. While cecal-ligation and puncture (CLP) is considered the gold standard model for sepsis research, it may not be preferable for experiments comparing animals of different size or under different dietary regimens. By comparing cecum size, shape, and cecal content characteristics in mice under different experimental conditions (aging, diabetes, pancreatitis), we show that cecum variability could be problematic for some CLP experiments. The cecal slurry (CS) injection model, in which the cecal contents of a laboratory animal are injected intraperitoneally to other animals, is …

Mtorc2 Is Required For Rit-Mediated Oxidative Stress Resistance, Weikang Cai, Douglas A. Andres

Molecular and Cellular Biochemistry Faculty Publications

Rit, a member of the Ras family of GTPases, has been shown to promote cell survival in response to oxidative stress, in part by directing an evolutionarily conserved p38 MAPK-Akt survival cascade. Aberrant Rit signaling has recently been implicated as a driver mutation in human cancer, adding importance to the characterization of critical Rit effector pathways. However, the mechanism by which Rit-p38 signaling regulated Akt activity was unknown. Here, we identify mTORC2 as a critical downstream mediator of Rit-dependent survival signaling in response to reactive oxygen species (ROS) stress. Rit interacts with Sin1 (MAPKAP1), and Rit loss compromises ROS-dependent mTORC2 …

Low Birth Weight Followed By Postnatal Over-Nutrition In The Guinea Pig Exposes A Predominant Player In The Development Of Vascular Dysfunction., Jennifer A Thompson, Ousseynou Sarr, Karolina Piorkowska, Robert Gros, Timothy Regnault

Paediatrics Publications

The association between intrauterine growth restriction (IUGR) and hypertension is well established, yet the interaction between IUGR and other pathogenic contributors remains ill-defined. This study examined the independent and interactive effects of fetal growth reduction resulting in low birth weight (LBW), and postnatal Western diet (WD) on vascular function. Growth reduction was induced in pregnant guinea pigs by uterine artery ablation. LBW and normal birth weight (NBW) offspring were randomly assigned to a control diet (CD) or a WD. In young adulthood, length-tension curves were generated in aortic rings and responses to methacholine (MCh) were evaluated in the carotid and …

Cd151-Α3Β1 Integrin Complexes Suppress Ovarian Tumor Growth By Repressing Slug-Mediated Emt And Canonical Wnt Signaling, Lauren A. Baldwin, John T. Hoff, Jason Lefringhouse, Michael Zhang, Changhe Jia, Zeyi Liu, Sonia Erfani, Hongyan Jin, Mei Xu, Qing-Bai She, John R. Van Nagell Jr., Chi Wang, Li Chen, Rina Plattner, David M. Kaetzel, Jia Luo, Michael Lu, Dava West, Chunming Liu, Fred R. Ueland, Ronny Drapkin, Binhua P. Zhou, Xiuwei H. Yang

Pharmacology and Nutritional Sciences Faculty Publications

Human ovarian cancer is diagnosed in the late, metastatic stages but the underlying mechanisms remain poorly understood. We report a surprising functional link between CD151-α3β1 integrin complexes and the malignancy of serous-type ovarian cancer. Analyses of clinical specimens indicate that CD151 expression is significantly reduced or diminished in 90% of metastatic lesions, while it remains detectable in 58% of primary tumors. These observations suggest a putative tumor-suppressing role of CD151 in ovarian cancer. Indeed, our analyses show that knocking down CD151 or α3 integrin enhances tumor cell proliferation, growth and ascites production in nude mice. These changes are accompanied by …

Cyclooxygenase-2, Prostaglandin E2, And Prostanoid Receptor Ep2 In Fluid Flow Shear Stress-Mediated Injury In The Solitary Kidney., Tarak Srivastava, Uri S. Alon, Patricia A. Cudmore, Belal Tarakji, Alexander Kats, Robert E. Garola, R Scott Duncan, Ellen T. Mccarthy, Ram Sharma, Mark L. Johnson, Lynda F. Bonewald, Ashraf El-Meanawy, Virginia J. Savin, Mukut Sharma

Manuscripts, Articles, Book Chapters and Other Papers

Hyperfiltration subjects podocytes to increased tensile stress and fluid flow shear stress (FFSS). We showed a 1.5- to 2.0-fold increase in FFSS in uninephrectomized animals and altered podocyte actin cytoskeleton and increased synthesis of prostaglandin E2 (PGE2) following in vitro application of FFSS. We hypothesized that increased FFSS mediates cellular changes through specific receptors of PGE2. Presently, we studied the effect of FFSS on cultured podocytes and decapsulated isolated glomeruli in vitro, and on solitary kidney in uninephrectomized sv129 mice. In cultured podocytes, FFSS resulted in increased gene and protein expression of cyclooxygenase (COX)-2 but not COX-1, prostanoid receptor EP2 …

Coral Spawning In The Gulf Of Oman And Relationship To Latitudinal Variation In Spawning Season In The Northwest Indian Ocean, E. J. Howells, D. Abrego, G. O. Vaughan, J. A. Burt

All Works

Despite a wealth of information on sexual reproduction in scleractinian corals, there are regional gaps in reproductive records. In the Gulf of the Oman in the Arabian Sea, reproductive timing was assessed in four common species of broadcast spawning corals using field surveys of gamete maturity and aquarium observations of spawning activity. The appearance of mature gametes within the same month for Acropora downingi, A. hemprichii, Cyphastrea microphthalma and Platygyra daedalea (≥ 75% of colonies, n = 848) indicated a synchronous and multi-specific spawning season. Based on gamete disappearance and direct observations, spawning predominantly occurred during April in 2013 (75- …

Expression Of Suppressor Of Cytokine Signaling 1 (Socs1) Impairs Viral Clearance And Exacerbates Lung Injury During Influenza Infection., Keer Sun, Sharon Salmon, Vijaya Kumar Yajjala, Christopher Bauer, Dennis W. Metzger

Journal Articles: Pathology and Microbiology

Suppressor of cytokine signaling (SOCS) proteins are inducible feedback inhibitors of cytokine signaling. SOCS1-/- mice die within three weeks postnatally due to IFN-γ-induced hyperinflammation. Since it is well established that IFN-γ is dispensable for protection against influenza infection, we generated SOCS1-/-IFN-γ-/- mice to determine whether SOCS1 regulates antiviral immunity in vivo. Here we show that SOCS1-/-IFN-γ-/- mice exhibited significantly enhanced resistance to influenza infection, as evidenced by improved viral clearance, attenuated acute lung damage, and consequently increased survival rates compared to either IFN-γ-/- or WT animals. Enhanced viral clearance in SOCS1-/-IFN-γ-/- mice coincided with a rapid onset of adaptive immune …

Over-Expression Of Copper/Zinc Superoxide Dismutase In The Median Preoptic Nucleus Attenuates Chronic Angiotensin Ii-Induced Hypertension In The Rat., John P. Collister, Mitch Bellrichard, Donna Drebes, David Nahey, Jun Tian, Matthew C. Zimmerman

Journal Articles: Cellular & Integrative Physiology

The brain senses circulating levels of angiotensin II (AngII) via circumventricular organs, such as the subfornical organ (SFO), and is thought to adjust sympathetic nervous system output accordingly via this neuro-hormonal communication. However, the cellular signaling mechanisms involved in these communications remain to be fully understood. Previous lesion studies of either the SFO, or the downstream median preoptic nucleus (MnPO) have shown a diminution of the hypertensive effects of chronic AngII, without providing a clear explanation as to the intracellular signaling pathway(s) involved. Additional studies have reported that over-expressing copper/zinc superoxide dismutase (CuZnSOD), an intracellular superoxide (O2·-) scavenging enzyme, in …

Syndecan 4 Is Required For Endothelial Alignment In Flow And Atheroprotective Signaling, Nicolas Baeyens, Mary Jo Mulligan-Kehoe, Federico Corti, David D. Simon, Tyler D. Ross, John M. Rhodes, Thomas Z. Wang

Dartmouth Scholarship

Atherosclerotic plaque localization correlates with regions of disturbed flow in which endothelial cells (ECs) align poorly, whereas sustained laminar flow correlates with cell alignment in the direction of flow and resistance to atherosclerosis. We now report that in hypercholesterolemic mice, deletion of syndecan 4 (S4−/−) drastically increased atherosclerotic plaque burden with the appearance of plaque in normally resistant locations. Strikingly, ECs from the thoracic aortas of S4−/− mice were poorly aligned in the direction of the flow. Depletion of S4 in human umbilical vein endothelial cells (HUVECs) using shRNA also inhibited flow-induced alignment in vitro, which was rescued by re-expression …

The Ethics Of Animal Research: A Survey Of Pediatric Health Care Workers, Ari Joffe, Meredith Bara, Natalie Anton, Nathan Nobis

Experimentation Collection

Introduction: Pediatric health care workers (HCW) often perform, promote, and advocate use of public funds for animal research (AR). We aim to determine whether HCW consider common arguments (and counterarguments) in support (or not) of AR convincing.

Design: After development and validation, an e-mail survey was sent to all pediatricians and pediatric intensive care unit nurses and respiratory therapists (RTs) affiliated with a Canadian University. We presented questions about demographics, support for AR, and common arguments (with their counterarguments) to justify the moral permissibility (or not) of AR. Responses are reported using standard tabulations. Responses of pediatricians and nurses/RTs were …

Suppression Of Invasion And Metastasis Of Triple-Negative Breast Cancer Lines By Pharmacological Or Genetic Inhibition Of Slug Activity., Giovanna Ferrari-Amorotti, Claudia Chiodoni, Fei Shen, Sara Cattelani, Angela Rachele Soliera, Gloria Manzotti, Giulia Grisendi, Massimo Dominici, Francesco Rivasi, Mario Paolo Colombo, Alessandro Fatatis, Bruno Calabretta

Department of Cancer Biology Faculty Papers

Most triple-negative breast cancers (TNBCs) exhibit gene expression patterns associated with epithelial-to-mesenchymal transition (EMT), a feature that correlates with a propensity for metastatic spread. Overexpression of the EMT regulator Slug is detected in basal and mesenchymal-type TNBCs and is associated with reduced E-cadherin expression and aggressive disease. The effects of Slug depend, in part, on the interaction of its N-terminal SNAG repressor domain with the chromatin-modifying protein lysine demethylase 1 (LSD1); thus, we investigated whether tranylcypromine [also known as trans-2-phenylcyclopropylamine hydrochloride (PCPA) or Parnate], an inhibitor of LSD1 that blocks its interaction with Slug, suppresses the migration, invasion, and metastatic …

Site-Specific Mutation Of The Sensor Kinase Gras In Staphylococcus Aureus Alters The Adaptive Response To Distinct Cationic Antimicrobial Peptides, Ambrose L. Cheung, Arnold S. Bayer, Michael R. Yeaman, Yan Q. Xiong, Alan J. Waring, Guido Memmi, Niles Donegan

Dartmouth Scholarship

The Staphylococcus aureus two-component regulatory system, GraRS, is involved in resistance to killing by distinct host defense cationic antimicrobial peptides (HD-CAPs). It is believed to regulate downstream target genes such as mprF and dltABCD to modify the S. aureus surface charge. However, the detailed mechanism(s) by which the histidine kinase, GraS, senses specific HD-CAPs is not well defined. Here, we studied a well-characterized clinical methicillin-resistant S. aureus (MRSA) strain (MW2), its isogenic graS deletion mutant (ΔgraS strain), a nonameric extracellular loop mutant (ΔEL strain), and four residue-specific ΔEL mutants (D37A, P39A, P39S, and D35G D37G D41G strains). The ΔgraS and …

Mastl Kinase, A Promising Therapeutic Target, Promotes Cancer Recurrence., Ling Wang, Vivian Q. Luong, Peter J. Giannini, Aimin Peng

Journal Articles: College of Dentistry

Mastl kinase promotes mitotic progression and cell cycle reentry after DNA damage. We report here that Mastl is frequently upregulated in various types of cancer. This upregulation was correlated with cancer progression in breast and oral cancer, poor patient survival in breast cancer, and tumor recurrence in head and neck squamous cell carcinoma. We further investigated the role of Mastl in tumor resistance using cell lines derived from the initial and recurrent tumors of the same head and neck squamous cell carcinoma patients. Ectopic expression of Mastl in the initial tumor cells strongly promoted cell proliferation in the presence of …

Simplified Post Processing Of Cine Dense Cardiovascular Magnetic Resonance For Quantification Of Cardiac Mechanics, Jonathan D. Suever, Gregory J. Wehner, Christopher M. Haggerty, Linyuan Jing, Sean M. Hamlet, Cassi M. Binkley, Sage P. Kramer, Andrea C. Mattingly, David K. Powell, Kenneth C. Bilchick, Frederick H. Epstein, Brandon K. Fornwalt

Saha Cardiovascular Research Center Faculty Publications

BACKGROUND: Cardiovascular magnetic resonance using displacement encoding with stimulated echoes (DENSE) is capable of assessing advanced measures of cardiac mechanics such as strain and torsion. A potential hurdle to widespread clinical adoption of DENSE is the time required to manually segment the myocardium during post-processing of the images. To overcome this hurdle, we proposed a radical approach in which only three contours per image slice are required for post-processing (instead of the typical 30-40 contours per image slice). We hypothesized that peak left ventricular circumferential, longitudinal and radial strains and torsion could be accurately quantified using this simplified analysis.

METHODS …

The Omega-3 Fatty Acid Docosahexaenoic Acid Attenuates Organic Dust-Induced Airway Inflammation., Tara M. Nordgren, Taylor D. Friemel, Art J. Heires, Jill A. Poole, Todd A. Wyatt, Debra J. Romberger

Journal Articles: Pulmonary & Critical Care Med

Workers exposed to organic dusts from concentrated animal feeding operations (CAFOs) are at risk for developing airway inflammatory diseases. Available preventative and therapeutic measures for alleviating dust-induced lung disease are inadequate. Because omega-3 fatty acids can mitigate inflammatory processes, we aimed to determine whether nutritional supplementation with the omega-3 fatty acid docosahexaenoic acid (DHA) could reduce the airway inflammatory consequences of exposures to organic dust. Aqueous extracts of organic dusts from swine CAFOs (ODE) were utilized. In DHA-pretreated human bronchial epithelial cells, lung fibroblasts, monocyte cell cultures, and precision-cut murine lung slices, we found that DHA pretreatment dose-dependently decreased ODE-induced …

Aquatic Hazard Assessment Of A Commercial Sample Of Naphthenic Acids., James P. Swigert, Carol Lee, Diana C.L. Wong, Russell White, Alan G. Scarlett, Charles E. West, Steven J. Rowland

More Faculty of Science and Engineering Research

This paper presents chemical composition and aquatic toxicity characteristics of a commercial sample of naphthenic acids (NAs). Naphthenic acids are derived from the refining of petroleum middle distillates and can contribute to refinery effluent toxicity. NAs are also present in oil sands process-affected water (OSPW), but differences in the NAs compositions from these sources precludes using a common aquatic toxicity dataset to represent the aquatic hazards of NAs from both origins. Our chemical characterization of a commercial sample of NAs showed it to contain in order of abundance, 1-ring>2-ring>acyclic>3-ring acids (∼84%). Also present were monoaromatic acids (7%) …

Swelling And Eicosanoid Metabolites Differentially Gate Trpv4 Channels In Retinal Neurons And Glia., Daniel A. Ryskamp, Andrew O. Jo, Amber M M. Frye, Felix Vazquez-Chona, Nanna Macaulay, Wallace B. Thoreson, David Križaj

Journal Articles: Ophthalmology

Activity-dependent shifts in ionic concentrations and water that accompany neuronal and glial activity can generate osmotic forces with biological consequences for brain physiology. Active regulation of osmotic gradients and cellular volume requires volume-sensitive ion channels. In the vertebrate retina, critical support to volume regulation is provided by Müller astroglia, but the identity of their osmosensor is unknown. Here, we identify TRPV4 channels as transducers of mouse Müller cell volume increases into physiological responses. Hypotonic stimuli induced sustained [Ca(2+)]i elevations that were inhibited by TRPV4 antagonists and absent in TRPV4(-/-) Müller cells. Glial TRPV4 signals were phospholipase A2- and cytochrome P450-dependent, …

The Formin Fmnl3 Assembles Plasma Membrane Protrusions That Participate In Cell–Cell Adhesion, Timothy J. Gauvin, Lorna E. Young, Henry N. Higgs

Dartmouth Scholarship

FMNL3 is a vertebrate-specific formin protein previously shown to play a role in angiogenesis and cell migration. Here we define the cellular localization of endogenous FMNL3, the dynamics of GFP-tagged FMNL3 during cell migration, and the effects of FMNL3 suppression in mammalian culture cells. The majority of FMNL3 localizes in a punctate pattern, with >95% of these puncta being indistinguishable from the plasma membrane by fluorescence microscopy. A small number of dynamic cytoplasmic FMNL3 patches also exist, which enrich near cell–cell contact sites and fuse with the plasma membrane at these sites. These cytoplasmic puncta appear to be part of …

Cannabinoid Receptor 2 Agonist Attenuates Pain Related Behavior In Rats With Chronic Alcohol/High Fat Diet Induced Pancreatitis, Liping Zhang, Robert H. Kline Iv, Terry A. Mcnearney, Michael P. Johnson, Karin Westlund High

Physiology Faculty Publications

BACKGROUND: Chronic Pancreatitis (CP) is a complex and multifactorial syndrome. Many contributing factors result in development of dysfunctional pain in a significant number of patients. Drugs developed to treat a variety of pain states fall short of providing effective analgesia for patients with chronic pancreatitis, often providing minimal to partial pain relief over time with significant side effects. Recently, availability of selective pharmacological tools has enabled great advances in our knowledge of the role of the cannabinoid receptors in pathophysiology. In particular, cannabinoid receptor 2 (CB2) has emerged as an attractive target for management of chronic pain, as demonstrated in …

Alzheimer's Therapeutics Targeting Amyloid Beta 1-42 Oligomers I: Abeta 42 Oligomer Binding To Specific Neuronal Receptors Is Displaced By Drug Candidates That Improve Cognitive Deficits, Nicholas J. Izzo, Agnes Staniszewski, Lillian To, Mauro Fa, Andrew F. Teich, Faisal Saeed, Harrison Wostein, Thomas Walko Iii, Anisha Vaswani, Meghan Wardius, Zanobia Syed, Jessica Ravenscroft, Kelsie Mozzoni, Colleen Silky, Courtney Rehak, Raymond Yurko, Patricia Finn, Gary Look, Gilbert Rishton, Hank Safferstein, Miles Miller, Conrad Johanson, Edward Stopa, Manfred Windisch, Birgit Hutter-Paier, Mehrdad Shamloo, Ottavio Arancio, Harry Levine Iii, Susan M. Catalano

Sanders-Brown Center on Aging Faculty Publications

Synaptic dysfunction and loss caused by age-dependent accumulation of synaptotoxic beta amyloid (Abeta) 1-42 oligomers is proposed to underlie cognitive decline in Alzheimer's disease (AD). Alterations in membrane trafficking induced by Abeta oligomers mediates reduction in neuronal surface receptor expression that is the basis for inhibition of electrophysiological measures of synaptic plasticity and thus learning and memory. We have utilized phenotypic screens in mature, in vitro cultures of rat brain cells to identify small molecules which block or prevent the binding and effects of Abeta oligomers. Synthetic Abeta oligomers bind saturably to a single site on neuronal synapses and induce …

Alzheimer's Therapeutics Targeting Amyloid Beta 1–42 Oligomers Ii: Sigma-2/Pgrmc1 Receptors Mediate Abeta 42 Oligomer Binding And Synaptotoxicity, Nicholas J. Izzo, Jinbin Xu, Chenbo Zeng, Molly J. Kirk, Kelsie Mozzoni, Colleen Silky, Courtney Rehak, Raymond Yurko, Gary Look, Gilbert Rishton, Hank Safferstein, Carlos Cruchaga, Alison Goate, Michael A. Cahill, Ottavio Arancio, Robert H. Mach, Rolf Craven, Elizabeth Head, Harry Levine Iii, Tara L. Spires-Jones, Susan M. Catalano

Sanders-Brown Center on Aging Faculty Publications

Amyloid beta (Abeta) 1-42 oligomers accumulate in brains of patients with Mild Cognitive Impairment (MCI) and disrupt synaptic plasticity processes that underlie memory formation. Synaptic binding of Abeta oligomers to several putative receptor proteins is reported to inhibit long-term potentiation, affect membrane trafficking and induce reversible spine loss in neurons, leading to impaired cognitive performance and ultimately to anterograde amnesia in the early stages of Alzheimer's disease (AD). We have identified a receptor not previously associated with AD that mediates the binding of Abeta oligomers to neurons, and describe novel therapeutic antagonists of this receptor capable of blocking Abeta toxic …

Nerve Growth Factor Regulates Neurolymphatic Remodeling During Corneal Inflammation And Resolution., Darci M. Fink, Alicia L. Connor, Philip M. Kelley, Maria M. Steele, Michael A. Hollingsworth, Richard M. Tempero

Journal Articles: Eppley Institute

The cellular and physiologic mechanisms that regulate the resolution of inflammation remain poorly defined despite their widespread importance in improving inflammatory disease outcomes. We studied the resolution of two cardinal signs of inflammation-pain and swelling-by investigating molecular mechanisms that regulate neural and lymphatic vessel remodeling during the resolution of corneal inflammation. A mouse model of corneal inflammation and wound recovery was developed to study this process in vivo. Administration of nerve growth factor (NGF) increased pain sensation and inhibited neural remodeling and lymphatic vessel regression processes during wound recovery. A complementary in vivo approach, the corneal micropocket assay, revealed that …