Medicine and Health Sciences Commons^™

Fibulin-2 Is Dispensable For Mouse Development And Elastic Fiber Formation, Francois-Xavier Sicot, Takeshi Tsuda, Dessislava Markova, John Klement, Machiko Arita, Rui-Zhu Zhang, Te-Cheng Pan, Robert P. Mecham, David E. Birk, Mon-Li Chu

Department of Dermatology and Cutaneous Biology Faculty Papers

Fibulin-2 is an extracellular matrix protein belonging to the five-member fibulin family, of which two members have been shown to play essential roles in elastic fiber formation during development. Fibulin-2 interacts with two major constituents of elastic fibers, tropoelastin and fibrillin-1, in vitro and localizes to elastic fibers in many tissues in vivo. The protein is prominently expressed during morphogenesis of the heart and aortic arch vessels and at early stages of cartilage development. To examine its role in vivo, we generated mice that do not express the fibulin-2 gene (Fbln2) through homologous recombination of embryonic stem cells. Unexpectedly, the …

Trk: A Neuromodulator Of Age-Specific Behavioral And Neurochemical Responses To Cocaine In Mice., Michelle Niculescu, Shane A Perrine, Jonathan S Miller, Michelle E Ehrlich, Ellen M Unterwald

Farber Institute for Neuroscience Faculty Papers

Responses to psychostimulants vary with age, but the molecular etiologies of these differences are largely unknown. The goal of the present research was to identify age-specific behavioral and molecular adaptations to cocaine and to elucidate the mechanisms involved therein. Postweanling, periadolescent, and adult male CD-1 mice were exposed to cocaine (20 mg/kg) for 7 d. The rewarding effects of cocaine were assessed, as were the response to a Trk antagonist and the regulation of dopamine and cAMP-regulated phosphoprotein, 32 kDa (DARPP-32). Cocaine was rewarding in both periadolescent and adult mice using a conditioned place preference procedure. In contrast, postweanling mice …

Adenomatous Polyposis Coli Is Present Near The Minimal Level Required For Accurate Graded Responses To The Wingless Morphogen, Hassina Benchabane, Edward G. Hughes, Carter M. Takacs, Jason R. Baird, Yashi Ahmed

Dartmouth Scholarship

The mechanisms by which the Wingless (Wg) morphogen modulates the activity of the transcriptional activator Armadillo (Arm) to elicit precise, concentration-dependent cellular responses remain uncertain. Arm is targeted for proteolysis by the Axin/Adenomatous polyposis coli (Apc1 and Apc2)/Zeste-white 3 destruction complex, and Wg-dependent inactivation of destruction complex activity is crucial to trigger Arm signaling. In the prevailing model for Wg transduction, only Axin levels limit destruction complex activity, whereas Apc is present in vast excess. To test this model, we reduced Apc activity to different degrees, and analyzed the effects on three concentration-dependent responses to Arm signaling that specify distinct …

Diverse Antidepressants Increase Cdp-Diacylglycerol Production And Phosphatidylinositide Resynthesis In Depression-Relevant Regions Of The Rat Brain, Kimberly R. Tyeryar, Habiba O.U. Vongtau, Ashiwel S. Undieh

College of Pharmacy Faculty Papers

BACKGROUND: Major depression is a serious mood disorder affecting millions of adults and children worldwide. While the etiopathology of depression remains obscure, antidepressant medications increase synaptic levels of monoamine neurotransmitters in brain regions associated with the disease. Monoamine transmitters activate multiple signaling cascades some of which have been investigated as potential mediators of depression or antidepressant drug action. However, the diacylglycerol arm of phosphoinositide signaling cascades has not been systematically investigated, even though downstream targets of this cascade have been implicated in depression. With the ultimate goal of uncovering the primary postsynaptic actions that may initiate cellular antidepressive signaling, we …

Repeat Length And Rna Expression Level Are Not Primary Determinants In Cug Expansion Toxicity In Drosophila Models, Gwenn Le Mée, Nader Ezzeddine, Michèle Capri, Ounissa Aït-Ahmed

Journal Articles

Evidence for an RNA gain-of-function toxicity has now been provided for an increasing number of human pathologies. Myotonic dystrophies (DM) belong to a class of RNA-dominant diseases that result from RNA repeat expansion toxicity. Specifically, DM of type 1 (DM1), is caused by an expansion of CUG repeats in the 3'UTR of the DMPK protein kinase mRNA, while DM of type 2 (DM2) is linked to an expansion of CCUG repeats in an intron of the ZNF9 transcript (ZNF9 encodes a zinc finger protein). In both pathologies the mutant RNA forms nuclear foci. The mechanisms that underlie the RNA pathogenicity …

Pioglitazone Inhibition Of Lipopolysaccharide-Induced Nitric Oxide Synthase Is Associated With Altered Activity Of P38 Map Kinase And Pi3k/Akt, Bin Xing, Tao Xin, Randy Lee Hunter, Guoying Bing

Neuroscience Faculty Publications

BACKGROUND: Previous studies have suggested that peroxisome proliferator activated receptor-gamma (PPAR-gamma)-mediated neuroprotection involves inhibition of microglial activation and decreased expression and activity of inducible nitric oxide synthase (iNOS); however, the underlying molecular mechanisms have not yet been well established. In the present study we explored: (1) the effect of the PPAR-gamma agonist pioglitazone on lipopolysaccharide (LPS)-induced iNOS activity and nitric oxide (NO) generation by microglia; (2) the differential role of p38 mitogen-activated protein kinase (p38 MAPK), c-Jun NH(2)-terminal kinase (JNK), and phosphoinositide 3-kinase (PI3K) on LPS-induced NO generation; and (3) the regulation of p38 MAPK, JNK, and PI3K by pioglitazone. …

Amp-Activated Protein Kinase Regulates Co2-Induced Alveolar Epithelial Dysfunction In Rats And Human Cells By Promoting Na,K-Atpase Endocytosis, István Vadász, Laura A. Dada, Arturo Briva, Humberto E. Trejo, Lynn C. Welch, Jiwang Chen, Peter T. Toth, Emilia Lecuona, Lee A. Witters, Paul T. Schumacker, Navdeep S. Chandel, Werner Seeger, Jacob I. Sznajder

Dartmouth Scholarship

Hypercapnia (elevated CO₂ levels) occurs as a consequence of poor alveolar ventilation and impairs alveolar fluid reabsorption (AFR) by promoting Na,K-ATPase endocytosis. We studied the mechanisms regulating CO₂-induced Na,K-ATPase endocytosis in alveolar epithelial cells (AECs) and alveolar epithelial dysfunction in rats. Elevated CO₂ levels caused a rapid activation of AMP-activated protein kinase (AMPK) in AECs, a key regulator of metabolic homeostasis. Activation of AMPK was mediated by a CO₂-triggered increase in intracellular Ca²⁺ concentration and Ca²⁺/calmodulin-dependent kinase kinase-β (CaMKK-β). Chelating intracellular Ca²⁺ or abrogating CaMKK-β function by gene silencing or …

Repression Of Hla By Rot Is Dependent On Sae In Staphylococcus Aureus, Dongmei Li, Ambrose Cheung

Dartmouth Scholarship

The regulatory locus sae is a two-component system in Staphylococcus aureus that regulates many important virulence factors, including alpha-toxin (encoded by hla) at the transcriptional level. The SarA homologs Rot and SarT were previously shown to be repressors of hla in selected S. aureus backgrounds. To delineate the interaction of rot and sae and the contribution of sarT to hla expression, an assortment of rot and sae isogenic single mutants, a rot sae double mutant, and a rot sae sarT markerless triple mutant were constructed from wild-type strain COL. Using Northern blot analysis and transcriptional reporter gene green fluorescent protein, …

Nitrated Alpha-Synuclein Immunity Accelerates Degeneration Of Nigral Dopaminergic Neurons., Eric J. Benner, Rebecca Banerjee, Ashley D. Reynolds, Simon Sherman, Vladimir M. Pisarev, Vladislav Tsiperson, Craig Nemachek, Pawel Ciborowski, Serge Przedborski, R. Lee Mosley, Howard Gendelman

Journal Articles: Eppley Institute

BACKGROUND: The neuropathology of Parkinson's disease (PD) includes loss of dopaminergic neurons in the substantia nigra, nitrated alpha-synuclein (N-alpha-Syn) enriched intraneuronal inclusions or Lewy bodies and neuroinflammation. While the contribution of innate microglial inflammatory activities to disease are known, evidence for how adaptive immune mechanisms may affect the course of PD remains obscure. We reasoned that PD-associated oxidative protein modifications create novel antigenic epitopes capable of peripheral adaptive T cell responses that could affect nigrostriatal degeneration.

METHODS AND FINDINGS: Nitrotyrosine (NT)-modified alpha-Syn was detected readily in cervical lymph nodes (CLN) from 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intoxicated mice. Antigen-presenting cells within the CLN …

Eomesodermin, A Target Gene Of Pou4f2, Is Required For Retinal Ganglion Cell And Optic Nerve Development In The Mouse., Chai-An Mao, Takae Kiyama, Ping Pan, Yasuhide Furuta, Anna-Katerina Hadjantonakis, William H Klein

Journal Articles

The mechanisms regulating retinal ganglion cell (RGC) development are crucial for retinogenesis and for the establishment of normal vision. However, these mechanisms are only vaguely understood. RGCs are the first neuronal lineage to segregate from pluripotent progenitors in the developing retina. As output neurons, RGCs display developmental features very distinct from those of the other retinal cell types. To better understand RGC development, we have previously constructed a gene regulatory network featuring a hierarchical cascade of transcription factors that ultimately controls the expression of downstream effector genes. This has revealed the existence of a Pou domain transcription factor, Pou4f2, that …

Gene Targeting In Adult Rhesus Macaque Fibroblasts, Daniel T. Meehan, Mary Ann Zink, Melissa Mahlen, Marilu Nelson, Warren G. Sanger, Shoukhrat M. Mitalipov, Don P. Wolf, Michel M. Ouellette, Robert B. Norgren

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: Gene targeting in nonhuman primates has the potential to produce critical animal models for translational studies related to human diseases. Successful gene targeting in fibroblasts followed by somatic cell nuclear transfer (SCNT) has been achieved in several species of large mammals but not yet in primates. Our goal was to establish the protocols necessary to achieve gene targeting in primary culture of adult rhesus macaque fibroblasts as a first step in creating nonhuman primate models of genetic disease using nuclear transfer technology.

RESULTS: A primary culture of adult male fibroblasts was transfected with hTERT to overcome senescence and allow …

Targeting Nf-Kappab: A Promising Molecular Therapy In Inflammatory Arthritis., Jorge A. Roman-Blas, Sergio A. Jimenez

Scleroderma Center Faculty Papers

The nuclear factor-kappa B family of transcription factors is intimately involved in the regulation of the inflammatory responses that play a fundamental role in the damage of articular tissues. Thus, many studies have examined the important contributions of components of the NF-kappaB signaling pathways to the pathogenesis of various rheumatic diseases and their pharmacologic modulation. Currently available therapeutic agents including nonsteroidal anti-inflammatory drugs, corticosteroids, nutraceuticals, and disease-modifying antirheumatic drugs, as well as novel specific small-molecule inhibitors have been employed. In addition, promising nucleic acid-based strategies have shown encouraging results. However, further research will be needed before NF-kappaB-aimed strategies become an …

Human Lens Lipids Differ Markedly From Those Of Commonly Used Experimental Animals, Jane Deeley, Todd W. Mitchell, Xiaojia Wei, Jurgen Korth, Jessica Hughes, Stephen J. Blanksby, Roger J. Truscott

Faculty of Health and Behavioural Sciences - Papers (Archive)

Electrospray ionisation tandem mass spectrometry has allowed the unambiguous identification andquantification of individual lens phospholipids in human and six animal models. Using this approach ca. 100unique phospholipids have been characterised. Parallel analysis of the same lens extracts by a novel directinsertionelectron-ionization technique found the cholesterol content of human lenses to be significantlyhigher (ca. 6 times) than lenses from the other animals.The most abundant phospholipids in all the lenses examined were choline-containing phospholipids. In rat,mouse, sheep, cow, pig and chicken, thesewere present largely as phosphatidylcholines, in contrast 66% of thetotal phospholipid in Homo sapienswas sphingomyelin, with the most abundant being dihydrosphingomyelins,in …

Temporal And Functional Profile Of The Transcriptional Regulatory Network In The Early Regenerative Response To Partial Hepatectomy In The Rat., Egle Juskeviciute, Rajanikanth Vadigepalli, Jan B Hoek

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: The goal of these studies was to characterize the transcriptional network regulating changes in gene expression in the remnant liver of the rat after 70% partial hepatectomy (PHx) during the early phase response including the transition of hepatocytes from the quiescent (G0) state and the onset of the G1 phase of the cell cycle. RESULTS: The transcriptome of remnant livers was monitored at 1, 2, 4, and 6 hours after PHx using cDNA microarrays. Differentially regulated genes were grouped into six clusters according their temporal expression profiles. Promoter regions of genes in these clusters were examined for shared transcription …

Transcriptional Regulatory Network Analysis During Epithelial-Mesenchymal Transformation Of Retinal Pigment Epithelium., Craig H Pratt, Rajanikanth Vadigepalli, Praveen Chakravarthula, Gregory E Gonye, Nancy J Philp, Gerald B Grunwald

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

PURPOSE: Phenotypic transformation of retinal pigment epithelial (RPE) cells contributes to the onset and progression of ocular proliferative disorders such as proliferative vitreoretinopathy (PVR). The formation of epiretinal membranes in PVR may involve an epithelial-mesenchymal transformation (EMT) of RPE cells as part of an aberrant wound healing response. While the underlying mechanism remains unclear, this likely involves changes in RPE cell gene expression under the control of specific transcription factors (TFs). Thus, the purpose of the present study was to identify TFs that may play a role in this process.

METHODS: Regulatory regions of genes that are differentially regulated during …

Cyan Fluorescent Protein Expression In Ganglion And Amacrine Cells In A Thy1-Cfp Transgenic Mouse Retina, Iona D Raymond, Alejandro Vila, Uyen-Chi N Huynh, Nicholas C Brecha

Journal Articles

PURPOSE: To characterize cyan fluorescent protein (CFP) expression in the retina of the thy1-CFP (B6.Cg-Tg(Thy1-CFP)23Jrs/J) transgenic mouse line.

METHODS: CFP expression was characterized using morphometric methods and immunohistochemistry with antibodies to neurofilament light (NF-L), neuronal nuclei (NeuN), POU-domain protein (Brn3a) and calretinin, which immunolabel ganglion cells, and syntaxin 1 (HPC-1), glutamate decarboxylase 67 (GAD(67)), GABA plasma membrane transporter-1 (GAT-1), and choline acetyltransferase (ChAT), which immunolabel amacrine cells.

RESULTS: CFP was extensively expressed in the inner retina, primarily in the inner plexiform layer (IPL), ganglion cell layer (GCL), nerve fiber layer, and optic nerve. CFP fluorescent cell bodies were in all …

Anticoagulant Rodenticide Intoxication In Animals – A Review, Ivan Valchev, Rumen Binev, Veska Yordanova, Yordan Nikolov

Turkish Journal of Veterinary & Animal Sciences

The newest measures for the control of harmful rodent populations are from the anticoagulant rodenticide group, which are divided into 2 subgroups: first and second generations, and indandione derivatives. Non-target organisms are potentially at risk of direct consumption of baits (primary hazard) and of eating poisoned rodents (secondary hazard). Anticoagulant rodenticides inhibit the enzyme vitamin K-dependent carboxylase and thus impair the reactivation of vitamin K1, indirectly affecting physiological blood coagulation. The diagnosis is made on the basis of clinical signs (massive hemorrhages), laboratory findings, and especially the changes in coagulation markers (APTT, PT, TT, PCT, ACT, FDPs, and PIVKA). The …

Elucidating A Normal Function Of Huntingtin By Functional And Microarray Analysis Of Huntingtin-Null Mouse Embryonic Fibroblasts., Hua Zhang, Sudipto Das, Quan-Zhen Li, Ioannis Dragatsis, Joyce Repa, Scott Zeitlin, György Hajnóczky, Ilya Bezprozvanny

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: The polyglutamine expansion in huntingtin (Htt) protein is a cause of Huntington's disease (HD). Htt is an essential gene as deletion of the mouse Htt gene homolog (Hdh) is embryonic lethal in mice. Therefore, in addition to elucidating the mechanisms responsible for polyQ-mediated pathology, it is also important to understand the normal function of Htt protein for both basic biology and for HD. RESULTS: To systematically search for a mouse Htt function, we took advantage of the Hdh +/- and Hdh-floxed mice and generated four mouse embryonic fibroblast (MEF) cells lines which contain a single copy of the Hdh …

Micrornas (Mirnas) In Neurodegenerative Diseases, Peter T. Nelson, Wang-Xia Wang, Bernard W. Rajeev

Sanders-Brown Center on Aging Faculty Publications

Aging-related neurodegenerative diseases (NDs) are the culmination of many different genetic and environmental influences. Prior studies have shown that RNAs are pathologically altered during the inexorable course of some NDs. Recent evidence suggests that microRNAs (miRNAs) may be a contributing factor in neurodegeneration. miRNAs are brain-enriched, small (~22 nucleotides) non-coding RNAs that participate in mRNA translational regulation. Although discovered in the framework of worm development, miRNAs are now appreciated to play a dynamic role in many mammalian brain-related biochemical pathways, including neuroplasticity and stress responses. Research about miRNAs in the context of neurodegeneration is accumulating rapidly, and the goal of …

Sevoflurane Enhances Ethanol-Induced Cardiac Preconditioning Through Modulation Of Protein Kinase C, Mitochondrial Katp Channels, And Nitric Oxide Synthase, In Guinea Pig Hearts., Kazuhiro Kaneda, Masami Miyamae, Shingo Sugioka, Chika Okusa, Yoshitaka Inamura, Naochika Domae, Junichiro Kotani, Vincent M. Figueredo

Division of Cardiology Faculty Papers

BACKGROUND: Volatile anesthetics and regular ethanol consumption induce cardioprotection mimicking ischemic preconditioning. We investigated whether sevoflurane enhances ethanol preconditioning and whether inhibition of protein kinase C (PKC) and mitochondrial K(ATP) channels attenuated this enhanced cardioprotection. The effects of regular ethanol consumption on expression of inducible (iNOS) and endothelial (eNOS) nitric oxide synthase were determined. METHODS: Isolated perfused guinea pig hearts underwent 30-min global ischemia and 120-min reperfusion (Control: CTL). The ethanol group (EtOH) received 2.5% ethanol in their drinking water for 6 wk. Anesthetic preconditioning was elicited by 10-min exposure to sevoflurane (1 minimum alveolar anesthetic concentration; 2%) in ethanol …

Application Of In Vivo Induced Antigen Technology (Iviat) To Bacillus Anthracis, Sean M Rollins, Amanda Peppercorn, John S Young, Melissa Drysdale, Andrea Baresch, Margaret V Bikowski, David A Ashford, Conrad P Quinn, Martin Handfield, Jeffrey D Hillman, C Rick Lyons, Theresa M Koehler, Stephen B Calderwood, Edward T Ryan

Journal Articles

In vivo induced antigen technology (IVIAT) is an immuno-screening technique that identifies bacterial antigens expressed during infection and not during standard in vitro culturing conditions. We applied IVIAT to Bacillus anthracis and identified PagA, seven members of a N-acetylmuramoyl-L-alanine amidase autolysin family, three P60 family lipoproteins, two transporters, spore cortex lytic protein SleB, a penicillin binding protein, a putative prophage holin, respiratory nitrate reductase NarG, and three proteins of unknown function. Using quantitative real-time PCR comparing RNA isolated from in vitro cultured B. anthracis to RNA isolated from BALB/c mice infected with virulent Ames strain B. anthracis, we confirmed induced …

Large Scale Variation In Enterococcus Faecalis Illustrated By The Genome Analysis Of Strain Og1rf, Agathe Bourgogne, Danielle A Garsin, Xiang Qin, Kavindra V Singh, Jouko Sillanpaa, Shailaja Yerrapragada, Yan Ding, Shannon Dugan-Rocha, Christian Buhay, Hua Shen, Guan Chen, Gabrielle Williams, Donna Muzny, Arash Maadani, Kristina A Fox, Jason Gioia, Lei Chen, Yue Shang, Cesar A Arias, Sreedhar R Nallapareddy, Meng Zhao, Vittal P Prakash, Shahreen Chowdhury, Huaiyang Jiang, Richard A Gibbs, Barbara E Murray, Sarah K Highlander, George M Weinstock

Journal Articles

BACKGROUND: Enterococcus faecalis has emerged as a major hospital pathogen. To explore its diversity, we sequenced E. faecalis strain OG1RF, which is commonly used for molecular manipulation and virulence studies.

RESULTS: The 2,739,625 base pair chromosome of OG1RF was found to contain approximately 232 kilobases unique to this strain compared to V583, the only publicly available sequenced strain. Almost no mobile genetic elements were found in OG1RF. The 64 areas of divergence were classified into three categories. First, OG1RF carries 39 unique regions, including 2 CRISPR loci and a new WxL locus. Second, we found nine replacements where a sequence …

Messenger Rna Half-Life Measurements In Mammalian Cells, Chyi-Ying A Chen, Nader Ezzeddine, Ann-Bin Shyu

Journal Articles

The recognition of the importance of mRNA turnover in regulating eukaryotic gene expression has mandated the development of reliable, rigorous, and "user-friendly" methods to accurately measure changes in mRNA stability in mammalian cells. Frequently, mRNA stability is studied indirectly by analyzing the steady-state level of mRNA in the cytoplasm; in this case, changes in mRNA abundance are assumed to reflect only mRNA degradation, an assumption that is not always correct. Although direct measurements of mRNA decay rate can be performed with kinetic labeling techniques and transcriptional inhibitors, these techniques often introduce significant changes in cell physiology. Furthermore, many critical mechanistic …

Dominance Of The Proximal Coordinate Frame In Determining The Locations Of Hippocampal Place Cell Activity During Navigation, Jennifer J Siegel, Joshua P Neunuebel, James J Knierim

Journal Articles

The place-specific activity of hippocampal cells provides downstream structures with information regarding an animal's position within an environment and, perhaps, the location of goals within that environment. In rodents, recent research has suggested that distal cues primarily set the orientation of the spatial representation, whereas the boundaries of the behavioral apparatus determine the locations of place activity. The current study was designed to address possible biases in some previous research that may have minimized the likelihood of observing place activity bound to distal cues. Hippocampal single-unit activity was recorded from six freely moving rats as they were trained to perform …