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Intravenous Inoculation Of Silver-Haired Bat Rabies Virus, But Not Of A Canine Strain, Elicits Lethal Encephalophathy In Mice By Fast Brain Invasion Via Neurosecretory Hypothalamic Fibers, Mirjam Ar Preuss, Marie-Luise Faber, Gene S. Tan, Bernhard Dietzschold, Matthias J. Schnell, Eberhard Weihe Sep 2008

Intravenous Inoculation Of Silver-Haired Bat Rabies Virus, But Not Of A Canine Strain, Elicits Lethal Encephalophathy In Mice By Fast Brain Invasion Via Neurosecretory Hypothalamic Fibers, Mirjam Ar Preuss, Marie-Luise Faber, Gene S. Tan, Bernhard Dietzschold, Matthias J. Schnell, Eberhard Weihe

Department of Microbiology and Immunology Faculty Papers

No abstract provided.


The Fgf System Has A Key Role In Regulating Vascular Integrity, Masahiro Murakami, Loc T. Nguyen, Zhen W. Zhang, Karen L. Moodie, Pater Carmellet, Radu V. Stan, Michael Simons Sep 2008

The Fgf System Has A Key Role In Regulating Vascular Integrity, Masahiro Murakami, Loc T. Nguyen, Zhen W. Zhang, Karen L. Moodie, Pater Carmellet, Radu V. Stan, Michael Simons

Dartmouth Scholarship

The integrity of the endothelial monolayer is essential to blood vessel homeostasis and active regulation of endothelial permeability. The FGF system plays important roles in a wide variety of physiologic and pathologic conditions; however, its role in the adult vasculature has not been defined. To assess the role of the FGF system in the adult endothelial monolayer, we disrupted FGF signaling in bovine aortic endothelial cells and human saphenous vein endothelial cells in vitro and in adult mouse and rat endothelial cells in vivo using soluble FGF traps or a dominant inhibitor of all FGF receptors. The inhibition of FGF …


Decreased Expression Of Caveolin 1 In Patients With Systemic Sclerosis: Crucial Role In The Pathogenesis Of Tissue Fibrosis., Francesco Del Galdo, Federica Sotgia, Cecilia J. De Almeida, Jean-Francois Jasmin, Megan Musick, Michael P. Lisanti, Sergio A. Jimenez Sep 2008

Decreased Expression Of Caveolin 1 In Patients With Systemic Sclerosis: Crucial Role In The Pathogenesis Of Tissue Fibrosis., Francesco Del Galdo, Federica Sotgia, Cecilia J. De Almeida, Jean-Francois Jasmin, Megan Musick, Michael P. Lisanti, Sergio A. Jimenez

Department of Medicine Faculty Papers

OBJECTIVE: Recent studies have implicated caveolin 1 in the regulation of transforming growth factor beta (TGFbeta) downstream signaling. Given the crucial role of TGFbeta in the pathogenesis of systemic sclerosis (SSc), we sought to determine whether caveolin 1 is also involved in the pathogenesis of tissue fibrosis in SSc. We analyzed the expression of CAV1 in affected SSc tissues, studied the effects of lack of expression of CAV1 in vitro and in vivo, and analyzed the effects of restoration of caveolin 1 function on the fibrotic phenotype of SSc fibroblasts in vitro.

METHODS: CAV1 expression in tissues was analyzed by …


Experimental Optic Neuritis Induced By A Demyelinating Strain Of Mouse Hepatitis Virus., Kenneth S. Shindler, Lawrence C. Kenyon, Mahasweta Dutt, Susan T. Hingley, Jayasri Das Sarma Sep 2008

Experimental Optic Neuritis Induced By A Demyelinating Strain Of Mouse Hepatitis Virus., Kenneth S. Shindler, Lawrence C. Kenyon, Mahasweta Dutt, Susan T. Hingley, Jayasri Das Sarma

Department of Neurology Faculty Papers

Optic neuritis (ON), an inflammatory demyelinating optic nerve disease, occurs in multiple sclerosis (MS). Pathological mechanisms and potential treatments for ON have been studied via experimental autoimmune MS models. However, evidence suggests that virus-induced inflammation is a likely etiology triggering MS and ON; experimental virus-induced ON models are therefore required. We demonstrate that MHV-A59, a mouse hepatitis virus (MHV) strain that causes brain and spinal cord inflammation and demyelination, induces ON by promoting mixed inflammatory cell infiltration. In contrast, MHV-2, a nondemyelinating MHV strain, does not induce ON. Results reveal a reproducible virus-induced ON model important for the evaluation of …


Toll-Like Receptor And Il-12 Signaling Control Susceptibility To Contact Hypersensitivity., Stefan F. Martin, Jan C. Dudda, Eva Bachtanian, Annalisa Lembo, Stefanie Liller, Christoph Dürr, Markus M. Heimesaat, Stefan Bereswill, György Fejer, Ralitsa Vassileva, Thilo Jakob, N Freudenberg, Christian C. Termeer, Caroline Johner, Chris Galanos, Ma Freudenberg Sep 2008

Toll-Like Receptor And Il-12 Signaling Control Susceptibility To Contact Hypersensitivity., Stefan F. Martin, Jan C. Dudda, Eva Bachtanian, Annalisa Lembo, Stefanie Liller, Christoph Dürr, Markus M. Heimesaat, Stefan Bereswill, György Fejer, Ralitsa Vassileva, Thilo Jakob, N Freudenberg, Christian C. Termeer, Caroline Johner, Chris Galanos, Ma Freudenberg

School of Biomedical Sciences

Allergic contact hypersensitivity (CHS) is a T cell-mediated inflammatory skin disease. Interleukin (IL)-12 is considered to be important in the generation of the allergen-specific T cell response. Loss of IL-12 function in IL-12Rbeta2-deficient mice, however, did not ameliorate the allergic immune response, suggesting alternate IL-12-independent pathways in the induction of CHS. Because exposure to contact allergens always takes place in the presence of microbial skin flora, we investigated the potential role of Toll-like receptors (TLRs) in the induction of CHS. Using mice deficient in TLR4, the receptor for bacterial lipopolysaccharide (LPS), IL-12 receptor (R) beta2, or both, we show that …


Contribution Of The Collagen Adhesin Acm To Pathogenesis Of Enterococcus Faecium In Experimental Endocarditis, Sreedhar R Nallapareddy, Kavindra V Singh, Barbara E Murray Sep 2008

Contribution Of The Collagen Adhesin Acm To Pathogenesis Of Enterococcus Faecium In Experimental Endocarditis, Sreedhar R Nallapareddy, Kavindra V Singh, Barbara E Murray

Faculty, Staff and Student Publications

Enterococcus faecium is a multidrug-resistant opportunist causing difficult-to-treat nosocomial infections, including endocarditis, but there are no reports experimentally demonstrating E. faecium virulence determinants. Our previous studies showed that some clinical E. faecium isolates produce a cell wall-anchored collagen adhesin, Acm, and that an isogenic acm deletion mutant of the endocarditis-derived strain TX0082 lost collagen adherence. In this study, we show with a rat endocarditis model that TX0082 Deltaacm::cat is highly attenuated versus wild-type TX0082, both in established (72 h) vegetations (P < 0.0001) and for valve colonization 1 and 3 hours after infection (P or=50-fold reduction relative to an Acm producer) were found in three of these five nonadherent isolates, including the sequenced strain TX0016, by quantitative reverse transcription-PCR, indicating that acm transcription is downregulated in vitro in these isolates. However, examination of TX0016 cells obtained directly from infected rat vegetations by flow cytometry showed that Acm was present on 40% of cells grown during infection. Finally, we demonstrated a significant reduction in E. faecium collagen adherence by affinity-purified anti-Acm antibodies from E. faecium endocarditis patient sera, suggesting that Acm may be a potential immunotarget for strategies to control this emerging pathogen.


Accelerated High Fidelity Prion Amplification Within And Across Prion Species Barriers, Kristi M. Green, Joaquín Castilla, Tanya S. Seward, Dana L. Napier, Jean E. Jewell, Claudio Soto, Glenn C. Telling Aug 2008

Accelerated High Fidelity Prion Amplification Within And Across Prion Species Barriers, Kristi M. Green, Joaquín Castilla, Tanya S. Seward, Dana L. Napier, Jean E. Jewell, Claudio Soto, Glenn C. Telling

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Experimental obstacles have impeded our ability to study prion transmission within and, more particularly, between species. Here, we used cervid prion protein expressed in brain extracts of transgenic mice, referred to as Tg(CerPrP), as a substrate for in vitro generation of chronic wasting disease (CWD) prions by protein misfolding cyclic amplification (PMCA). Characterization of this infectivity in Tg(CerPrP) mice demonstrated that serial PMCA resulted in the high fidelity amplification of CWD prions with apparently unaltered properties. Using similar methods to amplify mouse RML prions and characterize the resulting novel cervid prions, we show that serial PMCA abrogated a transmission barrier …


An Sp1/Sp3 Binding Polymorphism Confers Methylation Protection, Yanis A. Boumber, Yutaka Kondo, Xuqi Chen, Lanlan Shen, Yi Guo, Carmen Tellez, Marcos R H Estécio, Saira Ahmed, Jean-Pierre J. Issa Aug 2008

An Sp1/Sp3 Binding Polymorphism Confers Methylation Protection, Yanis A. Boumber, Yutaka Kondo, Xuqi Chen, Lanlan Shen, Yi Guo, Carmen Tellez, Marcos R H Estécio, Saira Ahmed, Jean-Pierre J. Issa

Faculty, Staff and Student Publications

Hundreds of genes show aberrant DNA hypermethylation in cancer, yet little is known about the causes of this hypermethylation. We identified RIL as a frequent methylation target in cancer. In search for factors that influence RIL hypermethylation, we found a 12-bp polymorphic sequence around its transcription start site that creates a long allele. Pyrosequencing of homozygous tumors revealed a 2.1-fold higher methylation for the short alleles (P<0.001). Bisulfite sequencing of cancers heterozygous for RIL showed that the short alleles are 3.1-fold more methylated than the long (P<0.001). The comparison of expression levels between unmethylated long and short EBV-transformed cell lines showed no difference in expression in vivo. Electrophorectic mobility shift assay showed that the inserted region of the long allele binds Sp1 and Sp3 transcription factors, a binding that is absent in the short allele. Transient transfection of RIL allele-specific transgenes showed no effects of the additional Sp1 site on transcription early on. However, stable transfection of methylation-seeded constructs showed gradually decreasing transcription levels from the short allele with eventual spreading of de novo methylation. In contrast, the long allele showed stable levels of expression over time as measured by luciferase and approximately 2-3-fold lower levels of methylation by bisulfite sequencing (P<0.001), suggesting that the polymorphic Sp1 site protects against time-dependent silencing. Our finding demonstrates that, in some genes, hypermethylation in cancer is dictated by protein-DNA interactions at the promoters and provides a novel mechanism by which genetic polymorphisms can influence an epigenetic state.


A Cyclin D1/Microrna 17/20 Regulatory Feedback Loop In Control Of Breast Cancer Cell Proliferation., Zuoren Yu, Chenguang Wang, Min Wang, Zhiping Li, Mathew C Casimiro, Manran Liu, Kongming Wu, James Whittle, Xiaoming Ju, Terry Hyslop, Peter Mccue, Richard G Pestell Aug 2008

A Cyclin D1/Microrna 17/20 Regulatory Feedback Loop In Control Of Breast Cancer Cell Proliferation., Zuoren Yu, Chenguang Wang, Min Wang, Zhiping Li, Mathew C Casimiro, Manran Liu, Kongming Wu, James Whittle, Xiaoming Ju, Terry Hyslop, Peter Mccue, Richard G Pestell

Kimmel Cancer Center Faculty Papers

Decreased expression of specific microRNAs (miRNAs) occurs in human tumors, which suggests a function for miRNAs in tumor suppression. Herein, levels of the miR-17-5p/miR-20a miRNA cluster were inversely correlated to cyclin D1 abundance in human breast tumors and cell lines. MiR-17/20 suppressed breast cancer cell proliferation and tumor colony formation by negatively regulating cyclin D1 translation via a conserved 3' untranslated region miRNA-binding site, thereby inhibiting serum-induced S phase entry. The cell cycle effect of miR-17/20 was abrogated by cyclin D1 siRNA and in cyclin D1-deficient breast cancer cells. Mammary epithelial cell-targeted cyclin D1 expression induced miR-17-5p and miR-20a expression …


The Aryl Hydrocarbon Receptor Binds To E2f1 And Inhibits E2f1-Induced Apoptosis., Jennifer L Marlowe, Yunxia Fan, Xiaoqing Chang, Li Peng, Erik S Knudsen, Ying Xia, Alvaro Puga Aug 2008

The Aryl Hydrocarbon Receptor Binds To E2f1 And Inhibits E2f1-Induced Apoptosis., Jennifer L Marlowe, Yunxia Fan, Xiaoqing Chang, Li Peng, Erik S Knudsen, Ying Xia, Alvaro Puga

Kimmel Cancer Center Faculty Papers

Cellular stress by DNA damage induces checkpoint kinase-2 (CHK2)-mediated phosphorylation and stabilization of the E2F1 transcription factor, leading to induction of apoptosis by activation of a subset of proapoptotic E2F1 target genes, including Apaf1 and p73. This report characterizes an interaction between the aryl hydrocarbon (Ah) receptor (AHR), a ligand-activated transcription factor, and E2F1 that results in the attenuation of E2F1-mediated apoptosis. In Ahr(-/-) fibroblasts stably transfected with a doxycycline-regulated AHR expression vector, inhibition of AHR expression causes a significant elevation of oxidative stress, gammaH2A.X histone phosphorylation, and E2F1-dependent apoptosis, which can be blocked by small interfering RNA-mediated knockdown of …


Sumoylation Regulates Lamin A Function And Is Lost In Lamin A Mutants Associated With Familial Cardiomyopathies, Yu-Qian Zhang, Kevin D. Sarge Jul 2008

Sumoylation Regulates Lamin A Function And Is Lost In Lamin A Mutants Associated With Familial Cardiomyopathies, Yu-Qian Zhang, Kevin D. Sarge

Molecular and Cellular Biochemistry Faculty Publications

Lamin A mutations cause many diseases, including cardiomyopathies and Progeria Syndrome. The covalent attachment of small ubiquitin-like modifier (SUMO) polypeptides regulates the function of many proteins. Until now, no examples of human disease-causing mutations that occur within a sumoylation consensus sequence and alter sumoylation were known. We show that lamin A is sumoylated at lysine 201 and that two lamin A mutants associated with familial dilated cardiomyopathy, E203G and E203K, exhibit decreased sumoylation. E203 occupies the conserved +2 position in the sumoylation consensus Psi KXE. Lamin A mutants E203G, E203K, and K201R all exhibit a similar aberrant subcellular localization and …


Water-Soluble Fullerene (C60) Derivatives As Nonviral Gene-Delivery Vectors, Balaji Sitharaman, Tatiana Y Zakharian, Anita Saraf, Preeti Misra, Jared Ashcroft, Su Pan, Quynh P Pham, Antonios G Mikos, Lon J Wilson, David A Engler Jul 2008

Water-Soluble Fullerene (C60) Derivatives As Nonviral Gene-Delivery Vectors, Balaji Sitharaman, Tatiana Y Zakharian, Anita Saraf, Preeti Misra, Jared Ashcroft, Su Pan, Quynh P Pham, Antonios G Mikos, Lon J Wilson, David A Engler

Faculty, Staff and Student Publications

A new class of water-soluble C60 transfecting agents has been prepared using Hirsch-Bingel chemistry and assessed for their ability to act as gene-delivery vectors in vitro. In an effort to elucidate the relationship between the hydrophobicity of the fullerene core, the hydrophilicity of the water-solubilizing groups, and the overall charge state of the C60 vectors in gene delivery and expression, several different C60 derivatives were synthesized to yield either positively charged, negatively charged, or neutral chemical functionalities under physiological conditions. These fullerene derivatives were then tested for their ability to transfect cells grown in culture with DNA carrying the green …


Synaptotagmin-2 Controls Regulated Exocytosis But Not Other Secretory Responses Of Mast Cells*, Qun-Fang Wan, Alejandro Vila, Zhen-Yu Zhou, Ruth Heidelberger Jul 2008

Synaptotagmin-2 Controls Regulated Exocytosis But Not Other Secretory Responses Of Mast Cells*, Qun-Fang Wan, Alejandro Vila, Zhen-Yu Zhou, Ruth Heidelberger

Faculty, Staff and Student Publications

To better understand synaptic signaling at the mammalian rod bipolar cell terminal and pave the way for applying genetic approaches to the study of visual information processing in the mammalian retina, synaptic vesicle dynamics and intraterminal calcium were monitored in terminals of acutely isolated mouse rod bipolar cells and the number of ribbon-style active zones quantified. We identified a releasable pool, corresponding to a maximum of 7 s. The presence of a smaller, rapidly releasing pool and a small, fast component of refilling was also suggested. Following calcium channel closure, membrane surface area was restored to baseline with a time …


Beta3 Integrin Haplotype Influences Gene Regulation And Plasma Von Willebrand Factor Activity, Katie E. Payne, Paul F. Bray, Peter J. Grant, Angela M. Carter Jun 2008

Beta3 Integrin Haplotype Influences Gene Regulation And Plasma Von Willebrand Factor Activity, Katie E. Payne, Paul F. Bray, Peter J. Grant, Angela M. Carter

Department of Medicine Faculty Papers

The Leu33Pro polymorphism of the gene encoding beta(3) integrin (ITGB3) is associated with acute coronary syndromes and influences platelet aggregation. Three common promoter polymorphisms have also been identified. The aims of this study were to (1) investigate the influence of the ITGB3 -400C/A, -425A/C and -468G/A promoter polymorphisms on reporter gene expression and nuclear protein binding and (2) determine genotype and haplotype associations with platelet alpha(IIb)beta(3) receptor density. Promoter haplotypes were introduced into an ITGB3 promoter-pGL3 construct by site directed mutagenesis and luciferase reporter gene expression analysed in HEL and HMEC-1 cells. Binding of nuclear proteins was assessed by electrophoretic …


Nerve Growth Factor Regulation Of Cyclin D1 In Pc12 Cells Through A P21ras Extracellular Signal-Regulated Kinase Pathway Requires Cooperative Interactions Between Sp1 And Nuclear Factor-Kappab., Francesco Marampon, Mathew C Casimiro, Maofu Fu, Michael J Powell, Vladimir M Popov, Jaime Lindsay, Bianca M Zani, Carmela Ciccarelli, Genichi Watanabe, Richard J Lee, Richard G Pestell Jun 2008

Nerve Growth Factor Regulation Of Cyclin D1 In Pc12 Cells Through A P21ras Extracellular Signal-Regulated Kinase Pathway Requires Cooperative Interactions Between Sp1 And Nuclear Factor-Kappab., Francesco Marampon, Mathew C Casimiro, Maofu Fu, Michael J Powell, Vladimir M Popov, Jaime Lindsay, Bianca M Zani, Carmela Ciccarelli, Genichi Watanabe, Richard J Lee, Richard G Pestell

Department of Cancer Biology Faculty Papers

The PC12 pheochromocytoma cell line responds to nerve growth factor (NGF) by exiting from the cell cycle and differentiating to induce extending neurites. Cyclin D1 is an important regulator of G1/S phase cell cycle progression, and it is known to play a role in myocyte differentiation in cultured cells. Herein, NGF induced cyclin D1 promoter, mRNA, and protein expression via the p21(RAS) pathway. Antisense- or small interfering RNA to cyclin D1 abolished NGF-mediated neurite outgrowth, demonstrating the essential role of cyclin D1 in NGF-mediated differentiation. Expression vectors encoding mutants of the Ras/mitogen-activated protein kinase pathway, and chemical inhibitors, demonstrated NGF …


Skeletal Abnormalities In Mice Lacking Extracellular Matrix Proteins, Thrombospondin-1, Thrombospondin-3, Thrombospondin-5, And Type Ix Collagen, Karen L Posey, Kurt Hankenson, Alka C Veerisetty, Paul Bornstein, Jack Lawler, Jacqueline T Hecht Jun 2008

Skeletal Abnormalities In Mice Lacking Extracellular Matrix Proteins, Thrombospondin-1, Thrombospondin-3, Thrombospondin-5, And Type Ix Collagen, Karen L Posey, Kurt Hankenson, Alka C Veerisetty, Paul Bornstein, Jack Lawler, Jacqueline T Hecht

Faculty, Staff and Student Publications

Thrombospondin-5 (TSP5) is a large extracellular matrix glycoprotein found in musculoskeletal tissues. TSP5 mutations cause two skeletal dysplasias, pseudoachondroplasia and multiple epiphyseal dysplasia; both show a characteristic growth plate phenotype with retention of TSP5, type IX collagen (Col9), and matrillin-3 in the rough endoplasmic reticulum. Whereas most studies focus on defining the disease process, few functional studies have been performed. TSP5 knockout mice have no obvious skeletal abnormalities, suggesting that TSP5 is not essential in the growth plate and/or that other TSPs may compensate. In contrast, Col9 knockout mice have diminished matrillin-3 levels in the extracellular matrix and early-onset osteoarthritis. …


Demyelinating And Nondemyelinating Strains Of Mouse Hepatitis Virus Differ In Their Neural Cell Tropism., Jayasri Das Sarma, Kathryn Iacono, Lilli Gard, Ryan Marek, Lawrence C. Kenyon, Michael Koval, Susan R. Weiss Jun 2008

Demyelinating And Nondemyelinating Strains Of Mouse Hepatitis Virus Differ In Their Neural Cell Tropism., Jayasri Das Sarma, Kathryn Iacono, Lilli Gard, Ryan Marek, Lawrence C. Kenyon, Michael Koval, Susan R. Weiss

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Some strains of mouse hepatitis virus (MHV) can induce chronic inflammatory demyelination in mice that mimics certain pathological features of multiple sclerosis. We have examined neural cell tropism of demyelinating and nondemyelinating strains of MHV in order to determine whether central nervous system (CNS) cell tropism plays a role in demyelination. Previous studies demonstrated that recombinant MHV strains, isogenic other than for the spike gene, differ in the extent of neurovirulence and the ability to induce demyelination. Here we demonstrate that these strains also differ in their abilities to infect a particular cell type(s) in the brain. Furthermore, there is …


Neuromyelitis Optica Pathogenesis And Aquaporin 4, David J. Graber, Michael Levy, Douglas Kerr, William F. Wade May 2008

Neuromyelitis Optica Pathogenesis And Aquaporin 4, David J. Graber, Michael Levy, Douglas Kerr, William F. Wade

Dartmouth Scholarship

Neuromyelitis optica (NMO) is a severe, debilitating human disease that predominantly features immunopathology in the optic nerves and the spinal cord. An IgG1 autoantibody (NMO-IgG) that binds aquaporin 4 (AQP4) has been identified in the sera of a significant number of NMO patients, as well as in patients with two related neurologic conditions, bilateral optic neuritis (ON), and longitudinal extensive transverse myelitis (LETM), that are generally considered to lie within the NMO spectrum of diseases. NMO-IgG is not the only autoantibody found in NMO patient sera, but the correlation of pathology in central nervous system (CNS) with tissues that normally …


C-Jun Is A Negative Regulator Of Myelination., David B. Parkinson, Ambily Bhaskaran, Peter Arthur-Farraj, Luke A. Noon, Ashwin Woodhoo, Alison C. Lloyd, M. Laura Feltri, Lawrence Wrabetz, Axel Behrens, Rhona Mirsky, Kristján R. Jessen May 2008

C-Jun Is A Negative Regulator Of Myelination., David B. Parkinson, Ambily Bhaskaran, Peter Arthur-Farraj, Luke A. Noon, Ashwin Woodhoo, Alison C. Lloyd, M. Laura Feltri, Lawrence Wrabetz, Axel Behrens, Rhona Mirsky, Kristján R. Jessen

Peninsula Medical School

Schwann cell myelination depends on Krox-20/Egr2 and other promyelin transcription factors that are activated by axonal signals and control the generation of myelin-forming cells. Myelin-forming cells remain remarkably plastic and can revert to the immature phenotype, a process which is seen in injured nerves and demyelinating neuropathies. We report that c-Jun is an important regulator of this plasticity. At physiological levels, c-Jun inhibits myelin gene activation by Krox-20 or cyclic adenosine monophosphate. c-Jun also drives myelinating cells back to the immature state in transected nerves in vivo. Enforced c-Jun expression inhibits myelination in cocultures. Furthermore, c-Jun and Krox-20 show a …


C-Jun Is A Negative Regulator Of Myelination., David B. Parkinson, Ambily Bhaskaran, Peter Arthur-Farraj, Luke A. Noon, Ashwin Woodhoo, Alison C. Lloyd, M. Laura Feltri, Lawrence Wrabetz, Axel Behrens, Rhona Mirsky, Kristján R. Jessen May 2008

C-Jun Is A Negative Regulator Of Myelination., David B. Parkinson, Ambily Bhaskaran, Peter Arthur-Farraj, Luke A. Noon, Ashwin Woodhoo, Alison C. Lloyd, M. Laura Feltri, Lawrence Wrabetz, Axel Behrens, Rhona Mirsky, Kristján R. Jessen

Peninsula Medical School

Schwann cell myelination depends on Krox-20/Egr2 and other promyelin transcription factors that are activated by axonal signals and control the generation of myelin-forming cells. Myelin-forming cells remain remarkably plastic and can revert to the immature phenotype, a process which is seen in injured nerves and demyelinating neuropathies. We report that c-Jun is an important regulator of this plasticity. At physiological levels, c-Jun inhibits myelin gene activation by Krox-20 or cyclic adenosine monophosphate. c-Jun also drives myelinating cells back to the immature state in transected nerves in vivo. Enforced c-Jun expression inhibits myelination in cocultures. Furthermore, c-Jun and Krox-20 show a …


Energization-Dependent Endogenous Activation Of Proton Conductance In Skeletal Muscle Mitochondria., Nadeene Parker, Charles Affourtit, Antonio Vidal-Puig, Martin D. Brand May 2008

Energization-Dependent Endogenous Activation Of Proton Conductance In Skeletal Muscle Mitochondria., Nadeene Parker, Charles Affourtit, Antonio Vidal-Puig, Martin D. Brand

School of Biomedical Sciences

Leak of protons into the mitochondrial matrix during substrate oxidation partially uncouples electron transport from phosphorylation of ADP, but the functions and source of basal and inducible proton leak in vivo remain controversial. In the present study we describe an endogenous activation of proton conductance in mitochondria isolated from rat and mouse skeletal muscle following addition of respiratory substrate. This endogenous activation increased with time, required a high membrane potential and was diminished by high concentrations of serum albumin. Inhibition of this endogenous activation by GDP [classically considered specific for UCPs (uncoupling proteins)], carboxyatractylate and bongkrekate (considered specific for the …


Atf4 Is An Oxidative Stress–Inducible, Prodeath Transcription Factor In Neurons In Vitro And In Vivo, Philipp Lange, Juan Chavez, John T. Pinto, Giovanni Coppola, Chiao-Wang Sun, Tim Townes, Rajiv Ratan May 2008

Atf4 Is An Oxidative Stress–Inducible, Prodeath Transcription Factor In Neurons In Vitro And In Vivo, Philipp Lange, Juan Chavez, John T. Pinto, Giovanni Coppola, Chiao-Wang Sun, Tim Townes, Rajiv Ratan

NYMC Faculty Publications

Oxidative stress is pathogenic in neurological diseases, including stroke. The identity of oxidative stress-inducible transcription factors and their role in propagating the death cascade are not well known. In an in vitro model of oxidative stress, the expression of the bZip transcription factor activating transcription factor 4 (ATF4) was induced by glutathione depletion and localized to the promoter of a putative death gene in neurons. Germline deletion of ATF4 resulted in a profound reduction in oxidative stress-induced gene expression and resistance to oxidative death. In neurons, ATF4 modulates an early, upstream event in the death pathway, as resistance to oxidative …


The Synthetic Triterpenoid Cddo-Methyl Ester Modulates Microglial Activities, Inhibits Tnf Production, And Provides Dopaminergic Neuroprotection, Thi A. Tran, Melissa K. Mccoy, Michael B. Sporn, Malú G. Tansey May 2008

The Synthetic Triterpenoid Cddo-Methyl Ester Modulates Microglial Activities, Inhibits Tnf Production, And Provides Dopaminergic Neuroprotection, Thi A. Tran, Melissa K. Mccoy, Michael B. Sporn, Malú G. Tansey

Dartmouth Scholarship

Recent animal and human studies implicate chronic activation of microglia in the progressive loss of CNS neurons. The inflammatory mechanisms that have neurotoxic effects and contribute to neurodegeneration need to be elucidated and specifically targeted without interfering with the neuroprotective effects of glial activities. Synthetic triterpenoid analogs of oleanolic acid, such as methyl-2-cyano-3,12-dioxooleana-1,9-dien-28-oate (CDDO-Me, RTA 402) have potent anti-proliferative and differentiating effects on tumor cells, and anti-inflammatory activities on activated macrophages. We hypothesized that CDDO-Me may be able to suppress neurotoxic microglial activities while enhancing those that promote neuronal survival. Therefore, the aims of our study were to identify specific …


Rest Maintains Self-Renewal And Pluripotency Of Embryonic Stem Cells, Sanjay K Singh, Mohamedi N Kagalwala, Jan Parker-Thornburg, Henry Adams, Sadhan Majumder May 2008

Rest Maintains Self-Renewal And Pluripotency Of Embryonic Stem Cells, Sanjay K Singh, Mohamedi N Kagalwala, Jan Parker-Thornburg, Henry Adams, Sadhan Majumder

Faculty, Staff and Student Publications

The neuronal repressor REST (RE1-silencing transcription factor; also called NRSF) is expressed at high levels in mouse embryonic stem (ES) cells, but its role in these cells is unclear. Here we show that REST maintains self-renewal and pluripotency in mouse ES cells through suppression of the microRNA miR-21. We found that, as with known self-renewal markers, the level of REST expression is much higher in self-renewing mouse ES cells than in differentiating mouse ES (embryoid body, EB) cells. Heterozygous deletion of Rest (Rest+/-) and its short-interfering-RNA-mediated knockdown in mouse ES cells cause a loss of self-renewal-even when these cells are …


Cd73-Generated Adenosine Restricts Lymphocyte Migration Into Draining Lymph Nodes, Masahide Takedachi, Dongfeng Qu, Yukihiko Ebisuno, Hiroyuki Oohara, Michelle L Joachims, Stephanie T Mcgee, Emiko Maeda, Rodger P Mcever, Toshiyuki Tanaka, Masayuki Miyasaka, Shinya Murakami, Thomas Krahn, Michael R Blackburn, Linda F Thompson May 2008

Cd73-Generated Adenosine Restricts Lymphocyte Migration Into Draining Lymph Nodes, Masahide Takedachi, Dongfeng Qu, Yukihiko Ebisuno, Hiroyuki Oohara, Michelle L Joachims, Stephanie T Mcgee, Emiko Maeda, Rodger P Mcever, Toshiyuki Tanaka, Masayuki Miyasaka, Shinya Murakami, Thomas Krahn, Michael R Blackburn, Linda F Thompson

Faculty, Staff and Student Publications

After an inflammatory stimulus, lymphocyte migration into draining lymph nodes increases dramatically to facilitate the encounter of naive T cells with Ag-loaded dendritic cells. In this study, we show that CD73 (ecto-5'-nucleotidase) plays an important role in regulating this process. CD73 produces adenosine from AMP and is expressed on high endothelial venules (HEV) and subsets of lymphocytes. Cd73(-/-) mice have normal sized lymphoid organs in the steady state, but approximately 1.5-fold larger draining lymph nodes and 2.5-fold increased rates of L-selectin-dependent lymphocyte migration from the blood through HEV compared with wild-type mice 24 h after LPS administration. Migration rates of …


Assessment Of A Non-Invasive High-Throughput Classifier For Behaviours Associated With Sleep And Wake In Mice, Kevin D. Donohue, Dharshan C. Medonza, Eli R. Crane, Bruce F. O'Hara Apr 2008

Assessment Of A Non-Invasive High-Throughput Classifier For Behaviours Associated With Sleep And Wake In Mice, Kevin D. Donohue, Dharshan C. Medonza, Eli R. Crane, Bruce F. O'Hara

Biology Faculty Publications

This work presents a non-invasive high-throughput system for automatically detecting characteristic behaviours in mice over extended periods of time, useful for phenotyping experiments. The system classifies time intervals on the order of 2 to 4 seconds as corresponding to motions consistent with either active wake or inactivity associated with sleep. A single Polyvinylidine Difluoride (PVDF) sensor on the cage floor generates signals from motion resulting in pressure. This paper develops a linear classifier based on robust features extracted from normalized power spectra and autocorrelation functions, as well as novel features from the collapsed average (autocorrelation of complex spectrum), which characterize …


Maternal Cocaine Administration In Mice Alters Dna Methylation And Gene Expression In Hippocampal Neurons Of Neonatal And Prepubertal Offspring, Svetlana I. Novikova, Fang He, Jie Bai, Nicholas J. Cutrufello, Michael S. Lidow, Ashiwel S. Undieh Apr 2008

Maternal Cocaine Administration In Mice Alters Dna Methylation And Gene Expression In Hippocampal Neurons Of Neonatal And Prepubertal Offspring, Svetlana I. Novikova, Fang He, Jie Bai, Nicholas J. Cutrufello, Michael S. Lidow, Ashiwel S. Undieh

College of Pharmacy Faculty Papers

Previous studies documented significant behavioral changes in the offspring of cocaine-exposed mothers. We now explore the hypothesis that maternal cocaine exposure could alter the fetal epigenetic machinery sufficiently to cause lasting neurochemical and functional changes in the offspring. Pregnant CD1 mice were administered either saline or 20 mg/kg cocaine twice daily on gestational days 8-19. Male pups from each of ten litters of the cocaine and control groups were analyzed at 3 (P3) or 30 (P30) days postnatum. Global DNA methylation, methylated DNA immunoprecipitation followed by CGI(2) microarray profiling and bisulfite sequencing, as well as quantitative real-time RT-PCR gene expression …


Ly2109761, A Novel Transforming Growth Factor Beta Receptor Type I And Type Ii Dual Inhibitor, As A Therapeutic Approach To Suppressing Pancreatic Cancer Metastasis, Davide Melisi, Satoshi Ishiyama, Guido M Sclabas, Jason B Fleming, Qianghua Xia, Giampaolo Tortora, James L Abbruzzese, Paul J Chiao Apr 2008

Ly2109761, A Novel Transforming Growth Factor Beta Receptor Type I And Type Ii Dual Inhibitor, As A Therapeutic Approach To Suppressing Pancreatic Cancer Metastasis, Davide Melisi, Satoshi Ishiyama, Guido M Sclabas, Jason B Fleming, Qianghua Xia, Giampaolo Tortora, James L Abbruzzese, Paul J Chiao

Faculty, Staff and Student Publications

Most pancreatic cancer patients present with inoperable disease or develop metastases after surgery. Conventional therapies are usually ineffective in treating metastatic disease. It is evident that novel therapies remain to be developed. Transforming growth factor beta (TGF-beta) plays a key role in cancer metastasis, signaling through the TGF-beta type I/II receptors (TbetaRI/II). We hypothesized that targeting TbetaRI/II kinase activity with the novel inhibitor LY2109761 would suppress pancreatic cancer metastatic processes. The effect of LY2109761 has been evaluated on soft agar growth, migration, invasion using a fibroblast coculture model, and detachment-induced apoptosis (anoikis) by Annexin V flow cytometric analysis. The efficacy …


Disruption Of C-Jun Reduces Cellular Migration And Invasion Through Inhibition Of C-Src And Hyperactivation Of Rock Ii Kinase., Xuanmao Jiao, Sanjay Katiyar, Manran Liu, Susette C Mueller, Michael P. Lisanti, Anping Li, Timothy G Pestell, Kongming Wu, Xiaoming Ju, Zhiping Li, Erwin F Wagner, Tatsuo Takeya, Chenguang Wang, Richard G Pestell Apr 2008

Disruption Of C-Jun Reduces Cellular Migration And Invasion Through Inhibition Of C-Src And Hyperactivation Of Rock Ii Kinase., Xuanmao Jiao, Sanjay Katiyar, Manran Liu, Susette C Mueller, Michael P. Lisanti, Anping Li, Timothy G Pestell, Kongming Wu, Xiaoming Ju, Zhiping Li, Erwin F Wagner, Tatsuo Takeya, Chenguang Wang, Richard G Pestell

Kimmel Cancer Center Faculty Papers

The spread of metastatic tumors to different organs is associated with poor prognosis. The metastatic process requires migration and cellular invasion. The protooncogene c-jun encodes the founding member of the activator protein-1 family and is required for cellular proliferation and DNA synthesis in response to oncogenic signals and plays an essential role in chemical carcinogenesis. The role of c-Jun in cellular invasion remains to be defined. Genetic deletion of c-Jun in transgenic mice is embryonic lethal; therefore, transgenic mice encoding a c-Jun gene flanked by LoxP sites (c-jun(f/f)) were used. c-jun gene deletion reduced c-Src expression, hyperactivated ROCK II signaling, …


Trail Mediates Liver Injury By The Innate Immune System In The Bile Duct-Ligated Mouse., Alisan Kahraman, Fernando J. Barreyro, Steven F. Bronk, Nathan W. Werneburg, Justin L. Mott, Yuko Akazawa, Howard C Masuoka, Charles L Howe, Gregory J. Gores Apr 2008

Trail Mediates Liver Injury By The Innate Immune System In The Bile Duct-Ligated Mouse., Alisan Kahraman, Fernando J. Barreyro, Steven F. Bronk, Nathan W. Werneburg, Justin L. Mott, Yuko Akazawa, Howard C Masuoka, Charles L Howe, Gregory J. Gores

Journal Articles: Biochemistry & Molecular Biology

The contribution of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a death ligand expressed by cells of the innate immune system, to cholestatic liver injury has not been explored. Our aim was to ascertain if TRAIL contributes to liver injury in the bile duct-ligated (BDL) mouse. C57/BL6 wild-type (wt), TRAIL heterozygote (TRAIL(+/-)), and TRAIL knockout (TRAIL(-/-)) mice were used for these studies. Liver injury and fibrosis were examined 7 and 14 days after BDL, respectively. Hepatic TRAIL messenger RNA (mRNA) was 6-fold greater in BDL animals versus sham-operated wt animals (P < 0.01). The increased hepatic TRAIL expression was accompanied by an increase in liver accumulation of natural killer 1.1 (NK 1.1)-positive NK and natural killer T (NKT) cells, the predominant cell types expressing TRAIL. Depletion of NK 1.1-positive cells reduced hepatic TRAIL mRNA expression and serum alanine aminotransferase (ALT) values. Consistent with a role for NK/NKT cells in this model of liver injury, stress ligands necessary for their recognition of target cells were also up-regulated in hepatocytes following BDL. Compared to sham-operated wt mice, BDL mice displayed a 13-fold increase in terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and an 11-fold increase in caspase 3/7-positive hepatocytes (P < 0.01). The number of TUNEL and caspase 3/7-positive cells was reduced by >80% in BDL TRAIL knockout animals (P < 0.05). Likewise, liver histology, number of bile infarcts, serum ALT values, hepatic fibrosis, and animal survival were also improved in BDL TRAIL(-/-) animals as compared to wt animals. Conclusion: These observations support a pivotal role for TRAIL in cholestatic liver injury mediated by NK 1.1-positive NK/NKT cells.