Digital Commons Network^™

Insulin Acutely Improves Mitochondrial Function Of Rat And Human Skeletal Muscle By Increasing Coupling Efficiency Of Oxidative Phosphorylation., Raid B. Nisr, Charles Affourtit

School of Biomedical Sciences

Insulin is essential for the regulation of fuel metabolism and triggers the uptake of glucose by skeletal muscle. The imported glucose is either stored or broken down, as insulin stimulates glycogenesis and ATP synthesis. The mechanism by which ATP production is increased is incompletely understood at present and, generally, relatively little functional information is available on the effect of insulin on mitochondrial function. In this paper we have exploited extracellular flux technology to investigate insulin effects on the bioenergetics of rat (L6) and human skeletal muscle myoblasts and myotubes. We demonstrate that a 20-min insulin exposure significantly increases (i) the …

Galleria Mellonella Infection Model Demonstrates High Lethality Of St69 And St127 Uropathogenic E. Coli., Majed F. Alghoribi, Tarek M. Gibreel, Andrew R. Dodgson, Scott A. Beatson, Mathew Upton

School of Biomedical Sciences

Galleria mellonella larvae are an alternative in vivo model for investigating bacterial pathogenicity. Here, we examined the pathogenicity of 71 isolates from five leading uropathogenic E. coli (UPEC) lineages using G. mellonella larvae. Larvae were challenged with a range of inoculum doses to determine the 50% lethal dose (LD50) and for analysis of survival outcome using Kaplan-Meier plots. Virulence was correlated with carriage of a panel of 29 virulence factors (VF). Larvae inoculated with ST69 and ST127 isolates (10(4) colony-forming units/larvae) showed significantly higher mortality rates than those infected with ST73, ST95 and ST131 isolates, killing 50% of the larvae …

Comparison Of Intermittent And Continuous Exposures To Inorganic Mercury In The Mussel, Mytilus Edulis: Accumulation And Sub-Lethal Physiological Effects., D Amachree, Aj Moody, Rd Handy

School of Biological and Marine Sciences

Aquatic organisms are often subject to intermittent exposure to pollutants in real ecosystems. This study aimed to compare mercury accumulation and the physiological responses of mussels, Mytilus edulis during continuous and intermittent exposure to the metal. Mussels were treated in a semi-static, triplicated design to either a control (no added Hg) or 50 µg l(-1) Hg as HgCl2 in continuous (daily) or intermittent (2 day exposure, 2 days in clean seawater alternately) exposure for 14 days. A time-dependent increase in Hg accumulation was observed in the continuous exposure, while the intermittent treatment showed step-wise changes in Hg concentrations with the …

Effects Of Dietary Β-(1,3)(1,6)-D-Glucan Supplementation On Growth Performance, Intestinal Morphology And Haemato-Immunological Profile Of Mirror Carp (Cyprinus Carpio L.)., H. Kühlwein, D. L. Merrifield, M. D. Rawling, A. D. Foey, S. J. Davies

School of Biological and Marine Sciences

In recent years, aquaculture research has focused on probiotics, prebiotics, and β-glucans, in order to improve health status and growth performance. Information regarding the effects of β-glucan on growth performance and intestinal immunity of mirror carp (Cyprinus carpio L.) is scarce. An experiment was therefore conducted to investigate the effects of a yeast β-glucan preparation (MacroGard(®) ) on growth performance, intestinal morphology and haemato-immunological indices of mirror carp. Carp (initial weight 11.1 ± 0.0 g) were fed highly purified diets supplemented with 0% (control), 0.1%, 1% or 2% MacroGard(®) for 8 weeks. Fish fed diets containing 1% and 2% MacroGard(®) …

Minimal Effects Of Waterborne Exposure To Single-Walled Carbon Nanotubes On Behaviour And Physiology Of Juvenile Rainbow Trout (Oncorhynchus Mykiss)., D Boyle, Je Fox, Jm Akerman, Ka Sloman, Tb Henry, Rd Handy

School of Biological and Marine Sciences

Fish behaviours are often considered to be sensitive endpoints of waterborne contaminants, but little attention has been given to engineered nanomaterials. The present study aimed to determine the locomotor and social behaviours of rainbow trout (Oncorhynchus mykiss) during waterborne exposure to single-walled carbon nanotubes (SWCNTs), and to ascertain the physiological basis for any observed effects. Dispersed stock suspensions of SWCNTs were prepared by stirring in sodium dodecyl sulphate (SDS), an anionic surfactant, on an equal w/w basis. Trout were exposed to control (no SWCNT or SDS), 0.25 mg L(-1) SDS (dispersant control), or 0.25 mg L(-1) of SWCNT for 10 …

Obesity Reduces Left Ventricular Strains, Torsion, And Synchrony In Mouse Models: A Cine Displacement Encoding With Stimulated Echoes (Dense) Cardiovascular Magnetic Resonance Study, Sage P. Kramer, David K. Powell, Christopher M. Haggerty, Cassi M. Binkley, Andrea C. Mattingly, Lisa A. Cassis, Frederick H. Epstein, Brandon K. Fornwalt

Pediatrics Faculty Publications

BACKGROUND: Obesity affects a third of adults in the US and results in an increased risk of cardiovascular mortality. While the mechanisms underlying this increased risk are not well understood, animal models of obesity have shown direct effects on the heart such as steatosis and fibrosis, which may affect cardiac function. However, the effect of obesity on cardiac function in animal models is not well-defined. We hypothesized that diet-induced obesity in mice reduces strain, torsion, and synchrony in the left ventricle (LV).

METHODS: Ten 12-week-old C57BL/6 J mice were randomized to a high-fat or low-fat diet. After 5 months on …

Sphingosine-1-Phosphate-Mediated Mobilization Of Hematopoietic Stem/Progenitor Cells During Intravascular Hemolysis Requires Attenuation Of Sdf-1-Cxcr4 Retention Signaling In Bone Marrow, Kasia Mierzejewska, Yuri M. Klyachkin, Janina Ratajczak, Ahmed Abdel-Latif, Magda Kucia, Mariusz Z. Ratajczak

Saha Cardiovascular Research Center Faculty Publications

Sphingosine-1-phosphate (S1P) is a crucial chemotactic factor in peripheral blood (PB) involved in the mobilization process and egress of hematopoietic stem/progenitor cells (HSPCs) from bone marrow (BM). Since S1P is present at high levels in erythrocytes, one might assume that, by increasing the plasma S1P level, the hemolysis of red blood cells would induce mobilization of HSPCs. To test this assumption, we induced hemolysis in mice by employing phenylhydrazine (PHZ). We observed that doubling the S1P level in PB from damaged erythrocytes induced only a marginally increased level of mobilization. However, if mice were exposed to PHZ together with the …

Inflammatory Cytokine Gene Expression In Mesenteric Adipose Tissue During Acute Experimental Colitis, William Conan Mustain, Marlene E. Starr, Joseph Daniel Valentino, Donald A. Cohen, Daiki Okamura, Chi Wang, B. Mark Evers, Hiroshi Saito

Markey Cancer Center Faculty Publications

BACKGROUND: Production of inflammatory cytokines by mesenteric adipose tissue (MAT) has been implicated in the pathogenesis of inflammatory bowel disease (IBD). Animal models of colitis have demonstrated inflammatory changes within MAT, but it is unclear if these changes occur in isolation or as part of a systemic adipose tissue response. It is also unknown what cell types are responsible for cytokine production within MAT. The present study was designed to determine whether cytokine production by MAT during experimental colitis is depot-specific, and also to identify the source of cytokine production within MAT.

METHODS: Experimental colitis was induced in 6-month-old C57BL/6 …

Contrast Enhanced-Magnetic Resonance Imaging As A Surrogate To Map Verteporfin Delivery In Photodynamic Therapy, Kimberley S. Samkoe, Amber Bryant, Jason R. Gunn, Stephen P. Pereira, Tayyaba Hasan, Brian W. Pogue

Dartmouth Scholarship

The use of in vivo contrast-enhanced magnetic resonance (MR) imaging as a surrogate for photosensitizer (verteporfin) dosimetry in photodynamic therapy of pancreas cancer is demonstrated by correlating MR contrast uptake to ex vivo fluorescence images on excised tissue. An orthotopic pancreatic xenograft mouse model was used for the study. A strong correlation ([i]r=0.57 ) was found for bulk intensity measurements of T1-weighted gadolinium enhancement and verteporfin fluorescence in the tumor region of interest. The use of contrast-enhanced MR imaging shows promise as a method for treatment planning and photosensitizer dosimetry in human photodynamic therapy (PDT) of pancreas …

Sensitization Of Human Cancer Cells To Gemcitabine By The Chk1 Inhibitor Mk-8776: Cell Cycle Perturbation And Impact Of Administration Schedule In Vitro And In Vivo, Ryan Montano, Ruth Thompson, Injae Chung, Huagang Hou, Nadeem Khan, Alan Eastman

Dartmouth Scholarship

Chk1 inhibitors have emerged as promising anticancer therapeutic agents particularly when combined with antimetabolites such as gemcitabine, cytarabine or hydroxyurea. Here, we address the importance of appropriate drug scheduling when gemcitabine is combined with the Chk1 inhibitor MK-8776, and the mechanisms involved in the schedule dependence.

Enrichment And Training Improve Cognition In Rats With Cortical Malformations, Kyle R. Jenks, Marcella M. Lucas, Ben A. Duffy, Ashlee A. Robbins, Barjor Gimi, Jeremy M. Barry, Rod C. Scott

Dartmouth Scholarship

Children with malformations of cortical development (MCD) frequently have associated cognitive impairments which reduce quality of life. We hypothesized that cognitive deficits associated with MCD can be improved with environmental manipulation or additional training. The E17 methylazoxymethanol acetate (MAM) exposure model bears many anatomical hallmarks seen in human MCDs as well as similar behavioral and cognitive deficits. We divided control and MAM exposed Sprague-Dawley rats into enriched and non-enriched groups and tested performance in the Morris water maze. Another group similarly divided underwent sociability testing and also underwent Magnetic Resonance Imaging (MRI) scans pre and post enrichment. A third group …

Adiponectin Inhibits Oxidative/Nitrative Stress During Myocardial Ischemia And Reperfusion Via Pka Signaling., Yanqing Zhang, Xiao-Liang Wang, Jianli Zhao, Ya-Jing Wang, Wayne Bond Lau, Yue-Xing Yuan, Er-He Gao, Walter J. Koch, Xin-Liang Ma

Department of Emergency Medicine Faculty Papers

The cardioprotective effects of adiponectin (APN) against myocardial ischemia/reperfusion (MI/R) injury are well known. However, comprehension of the mechanisms mediating intracellular APN signaling remains incomplete. We recently demonstrate the antioxidant/antinitrative effects of APN are not dependent on AMPK. Protein kinase A (PKA) has been previously shown to be activated by APN, with uncertain relevance to APN cardiac protection. The current study determined whether the antioxidative/antinitrative effect of APN is mediated by PKA. Administration of APN (2 μg/g) 10 min before reperfusion significantly enhanced cardiac PKA activity, reduced oxidative stress, and decreased infarct size. Knockdown of cardiac PKA expression (PKA-KD) by …

Use Of Irf-3 And/Or Irf-7 Knockout Mice To Study Viral Pathogenesis: Lessons From A Murine Retrovirus-Induced Aids Model, Megan A. O'Connor, William R. Green

Dartmouth Scholarship

Interferon regulatory factor (IRF) regulation of the type I interferon response has not been extensively explored in murine retroviral infections. IRF-3(-/-) and select IRF-3/7(-/-) mice were resistant to LP-BM5-induced pathogenesis. However, further analyses strongly suggested that resistance could be attributed to strain 129-specific contamination of the known retrovirus resistance gene Fv1. Therefore, caution should be taken when interpreting phenotypes observed in these knockout mice, as strain 129-derived genetic polymorphisms may explain observed differences.

Defects In Synapse Structure And Function Precede Motor Neuron Degeneration In Drosophila Models Of Fus-Related Als., Mohammad Shahidullah, Sylvain J Le Marchand, Hong Fei, Jiaming Zhang, Udai Bhan Pandey, Matthew B. Dalva, Piera Pasinelli, Irwin B. Levitan

Department of Neuroscience Faculty Papers

Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease that leads invariably to fatal paralysis associated with motor neuron degeneration and muscular atrophy. One gene associated with ALS encodes the DNA/RNA-binding protein Fused in Sarcoma (FUS). There now exist two Drosophila models of ALS. In one, human FUS with ALS-causing mutations is expressed in fly motor neurons; in the other, the gene cabeza (caz), the fly homolog of FUS, is ablated. These FUS-ALS flies exhibit larval locomotor defects indicative of neuromuscular dysfunction and early death. The locus and site of initiation of this neuromuscular dysfunction remain unclear. We show here …

Analgesic Tolerance Of Opioid Agonists In Mutant Mu-Opioid Receptors Expressed In Sensory Neurons Following Intrathecal Plasmid Gene Delivery, Guangwen Li, Fei Ma, Yanping Gu, Li-Yen Mae Huang

Physiology Faculty Publications

Background: Phosphorylation sites in the C-terminus of mu-opioid receptors (MORs) are known to play critical roles in the receptor functions. Our understanding of their participation in opioid analgesia is mostly based on studies of opioid effects on mutant receptors expressed in in vitro preparations, including cell lines, isolated neurons and brain slices. The behavioral consequences of the mutation have not been fully explored due to the complexity in studies of mutant receptors in vivo. To facilitate the determination of the contribution of phosphorylation sites in MOR to opioid-induced analgesic behaviors, we expressed mutant and wild-type human MORs (hMORs) in sensory …

Neuronal Clearance Of Amyloid-Β By Endocytic Receptor Lrp1, Takahisa Kanekiyo, John R. Cirrito, Chia-Chen Liu, Mitsuru Shinohara, Jie Li, Dorothy R. Schuler, Motoko Shinohara, David M. Holtzman, Guojun Bu

Open Access Publications

Alzheimer's disease (AD) is the most prevalent form of dementia in the elderly population. Accumulation, aggregation, and deposition of amyloid-β (Aβ) peptides generated through proteolytic cleavage of amyloid precursor protein (APP) are likely initiating events in the pathogenesis of AD. While Aβ production is accelerated in familial AD, increasing evidence indicates that impaired clearance of Aβ is responsible for late-onset AD. Because Aβ is mainly generated in neurons, these cells are predicted to have the highest risk of encountering Aβ among all cell types in the brain. However, it is still unclear whether they are also involved in Aβ clearance. …

In Vivo Bioluminescence Imaging To Evaluate Systemic And Topical Antibiotics Against Community-Acquired Methicillin-Resistant Staphylococcus Aureus-Infected Skin Wounds In Mice, Yi Guo, Romela Irene Ramos, John S. Cho, Niles P. Donegan, Ambrose L. Cheung, Lloyd S. Miller

Dartmouth Scholarship

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) frequently causes skin and soft tissue infections, including impetigo, cellulitis, folliculitis, and infected wounds and ulcers. Uncomplicated CA-MRSA skin infections are typically managed in an outpatient setting with oral and topical antibiotics and/or incision and drainage, whereas complicated skin infections often require hospitalization, intravenous antibiotics, and sometimes surgery. The aim of this study was to devel

The Gating Charge Should Not Be Estimated By Fitting A Two-State Model To A Q-V Curve, Francisco Bezanilla, Carlos A. Villalba-Galea

School of Pharmacy Faculty Articles

The voltage dependence of charges in voltage-sensitive proteins, typically displayed as charge versus voltage (Q-V) curves, is often quantified by fitting it to a simple two-state Boltzmann function. This procedure overlooks the fact that the fitted parameters, including the total charge, may be incorrect if the charge is moving in multiple steps. We present here the derivation of a general formulation for Q-V curves from multistate sequential models, including the case of infinite number of states. We demonstrate that the commonly used method to estimate the charge per molecule using a simple Boltzmann fit is not only inadequate, but in …

Children's Ideas About The Moral Standing And Social Welfare Of Non-Human Species, Gail F. Melson

The Journal of Sociology & Social Welfare

Moral and social welfare issues related to humane treatment of animals confront children and continue to be important societal issues through adulthood. Despite this, children's moral reasoning about animals has been largely ignored. This paper addresses six questions concerning how children reason morally about non-human animals: (1) How do children think about the moral claims of animals? Is there a developmental progression in such reasoning? (2) How does moral reasoning about animals differ from moral reasoning about other life forms-plants and ecological systems? (3) What is the relation, if any, between children's moral reasoning about non-human animals and their moral …

Staff Views On The Involvement Of Animals In Care Home Life: An Exploratory Study, Jane Fossey, Vanessa Lawrence

The Journal of Sociology & Social Welfare

This qualitative study examined the views of one hundred and eight care staff working in fifteen care homes in the United Kingdom about the involvement Of animals in the care practices of the home. The perceived benefits and difficulties ofdelivering person-centered and psychosocial care, including the involvement of animals were explored. The findings describe the main themes related to animal involvement elicited from staff. These include the benefits to residents' well-being and the varying challenges that visiting and residential animals pose. The implicationsfor practice are discussed and the need for clearer information for care home teams is identified.

Occupational Injuries On Thoroughbred Horse Farms: A Description Of Latino And Non-Latino Workers' Experiences, Jennifer E. Swanberg, Jessica M. Clouser, Susan C. Westneat, Mary W. Marsh, Deborah B. Reed

Health, Behavior & Society Faculty Publications

Animal production is a dangerous industry and increasingly reliant on a Latino workforce. Within animal production, little is known about the risks or the occupational hazards of working on farms involved in various aspects of thoroughbred horse breeding. Extant research suggests that horse workers are at risk of musculoskeletal and respiratory symptoms, kicks, and other injuries. However, limited known research has examined the experiences of the industry's workers, including immigrant workers, despite their prominence and increased vulnerability. Using data collected from thoroughbred farm representatives via a phone-administered survey, a 2-hour face-to-face semi-structured interview, and farm injury logs, this article identifies …

Targeting Cell Cycle And Hormone Receptor Pathways In Cancer., C E S Comstock, M A Augello, J F Goodwin, R De Leeuw, M J Schiewer, W F Ostrander, R A Burkhart, A K Mcclendon, Peter Mccue, Edouard J. Trabulsi, Costas D. Lallas, Leonard G Gomella, Md, M M Centenera, Jonathan Brody, Md, L M Butler, W D Tilley, K E Knudsen, Phd

Department of Cancer Biology Faculty Papers

The cyclin/cyclin-dependent kinase (CDK)/retinoblastoma (RB)-axis is a critical modulator of cell cycle entry and is aberrant in many human cancers. New nodes of therapeutic intervention are needed that can delay or combat the onset of malignancies. The antitumor properties and mechanistic functions of PD-0332991 (PD; a potent and selective CDK4/6 inhibitor) were investigated using human prostate cancer (PCa) models and primary tumors. PD significantly impaired the capacity of PCa cells to proliferate by promoting a robust G1-arrest. Accordingly, key regulators of the G1-S cell cycle transition were modulated including G1 cyclins D, E and A. Subsequent investigation demonstrated the ability …

A Cell Permeable Peptide Targeting The Intracellular Loop 2 Of Endothelin B Receptor Reduces Pulmonary Hypertension In A Hypoxic Rat Model, Daniel S. Green, Chamila Rupasinghe, Rod Warburton, Jamie L. Wilson, Christine O. Sallum, Linda Taylor, Achan Yatawara, Dale Mierke, Peter Polgar, Nicholas Hill

Dartmouth Scholarship

Cell permeable peptides (CPP) aid cellular uptake of targeted cargo across the hydrophobic plasma membrane. CPP-mediated cargo delivery of receptor signaling motifs provides an opportunity to regulate specific receptor initiated signaling cascades. Both endothelin-1 receptors, ETA and ETB, have been targets of antagonist therapies for individuals with pulmonary arterial hypertension (PAH). These therapies have had success but have been accompanied by adverse reactions. Also, unlike the CPP which target specific signaling cascades, the antagonists target the entire function of the receptor. Using the CPP strategy of biased antagonism of the ETB receptor’s intracellular loop 2 (ICB2), we demonstrate blunting of …

Novel Pancreatic Cancer Cell Lines Derived From Genetically Engineered Mouse Models Of Spontaneous Pancreatic Adenocarcinoma: Applications In Diagnosis And Therapy., María P. Torres, Satyanarayana Rachagani, Joshua J. Souchek, Kavita Mallya, Sonny L. Johansson, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

Pancreatic cancer (PC) remains one of the most lethal human malignancies with poor prognosis. Despite all advances in preclinical research, there have not been significant translation of novel therapies into the clinics. The development of genetically engineered mouse (GEM) models that produce spontaneous pancreatic adenocarcinoma (PDAC) have increased our understanding of the pathogenesis of the disease. Although these PDAC mouse models are ideal for studying potential therapies and specific genetic mutations, there is a need for developing syngeneic cell lines from these models. In this study, we describe the successful establishment and characterization of three cell lines derived from two …

Short Duration Waveforms Recorded Extracellularly From Freely Moving Rats Are Representative Of Axonal Activity, Ashlee A. Robbins, Steven E. Fox, Gregory L. Holmes, Rod C. Scott, Jeremy M. Barry

Dartmouth Scholarship

While extracellular somatic action potentials from freely moving rats have been well characterized, axonal activity has not. We report direct extracellular tetrode recordings of putative axons whose principal feature is a short duration waveform (SDW) with an average peak-trough length less than 179 μs. While SDW recordings using tetrodes have previously been treated as questionable or classified as cells, we hypothesize that they are representative of axonal activity. These waveforms have significantly shorter duration than somatic action potentials, are triphasic and are therefore similar to classic descriptions of microelectrode recordings in white matter and of in vitro action potential propagation …

Intestinal Gucy2c Prevents Tgf-Β Secretion Coordinating Desmoplasia And Hyperproliferation In Colorectal Cancer., Ahmara V Gibbons, Jieru Egeria Lin, Gilbert Won Kim, Glen P Marszalowicz, Peng Li, Brian Arthur Stoecker, Erik S Blomain, Satish Rattan, Adam E. Snook, Stephanie Schulz, Scott A Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Tumorigenesis is a multistep process that reflects intimate reciprocal interactions between epithelia and underlying stroma. However, tumor-initiating mechanisms coordinating transformation of both epithelial and stromal components are not defined. In humans and mice, initiation of colorectal cancer is universally associated with loss of guanylin and uroguanylin, the endogenous ligands for the tumor suppressor guanylyl cyclase C (GUCY2C), disrupting a network of homeostatic mechanisms along the crypt-surface axis. Here, we reveal that silencing GUCY2C in human colon cancer cells increases Akt-dependent TGF-β secretion, activating fibroblasts through TGF-β type I receptors and Smad3 phosphorylation. In turn, activating TGF-β signaling induces fibroblasts to …

Bdnf In The Dentate Gyrus Is Required For Consolidation Of "Pattern-Separated" Memories., Pedro Bekinschtein, Brianne A Kent, Charlotte A Oomen, Gregory D Clemenson, Fred H Gage, Lisa M Saksida, Timothy J Bussey

Brain and Mind Institute Researchers' Publications

Successful memory involves not only remembering information over time, but also keeping memories distinct and less confusable. The computational process for making representations for similar input patterns more distinct from each other has been referred to as "pattern separation." In this work, we developed a set of behavioral conditions that allowed us to manipulate the load for pattern separation at different stages of memory. Thus, we provide experimental evidence that a brain-derived neurotrophic factor (BDNF)-dependent pattern separation process occurs during the encoding/storage/consolidation, but not the retrieval stage of memory processing. We also found that a spontaneous increase in BDNF in …

Evidence For Finely-Regulated Asynchronous Growth Of Toxoplasma Gondii Cysts Based On Data-Driven Model Selection, Adam M. Sullivan, Xiaopeng Zhao, Yasuhiro Suzuki, Eri Ochiai, Stephen Crutcher, Michael A. Gilchrist

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Toxoplasma gondii establishes a chronic infection by forming cysts preferentially in the brain. This chronic infection is one of the most common parasitic infections in humans and can be reactivated to develop life-threatening toxoplasmic encephalitis in immunocompromised patients. Host-pathogen interactions during the chronic infection include growth of the cysts and their removal by both natural rupture and elimination by the immune system. Analyzing these interactions is important for understanding the pathogenesis of this common infection. We developed a differential equation framework of cyst growth and employed Akaike Information Criteria (AIC) to determine the growth and removal functions that best describe …

Hrs Promotes Ubiquitination And Mediates Endosomal Trafficking Of Smoothened In Drosophila Hedgehog Signaling, Jun-Kai Fan, Kai Jiang, Yajuan Liu, Jianhang Jia

Markey Cancer Center Faculty Publications

In Hedgehog (Hh) signaling, the seven-transmembrane protein Smoothened (Smo) acts as a signal transducer that is regulated by phosphorylation, ubiquitination, and cell surface accumulation. However, it is not clear how Smo cell surface accumulation and intracellular trafficking are regulated. Here, we demonstrate that inactivation of Hrs by deletion or RNAi accumulates Smo in the late endosome that is marked by late endosome markers. Inactivation of Hrs enhances the wing defects caused by dominant-negative Smo. We show that Hrs promotes Smo ubiquitination, deleting the ubiquitin-interacting-motif (UIM) in Hrs abolishes the ability of Hrs to regulate Smo ubiquitination. However, the UIM domain …

Adam17-Mediated Processing Of Tnf-Α Expressed By Antiviral Effector Cd8+ T Cells Is Required For Severe T-Cell-Mediated Lung Injury, Matthew P. Deberge, Kenneth H. Ely, Guang-Shing Cheng, Richard I. Enelow

Dartmouth Scholarship

Influenza infection in humans evokes a potent CD8+ T-cell response, which is important for clearance of the virus but may also exacerbate pulmonary pathology. We have previously shown in mice that CD8+ T-cell expression of TNF-a is required for severe and lethal lung injury following recognition of an influenza antigen expressed by alveolar epithelial cells. Since TNF-a is first expressed as a transmembrane protein that is then proteolytically processed to release a soluble form, we sought to characterize the role of TNF-a processing in CD8+ T-cell-mediated injury. In this study we observed that inhibition of ADAM17-mediated processing of TNF-a by …