Medicine and Health Sciences Commons^™

A Direct Role For Secretory Phospholipase A2 And Lyso-Phosphatidylcholine In The Mediation Of Lipopolysaccharide-Induced Gastric Injury, Elizabeth J Dial, Duy M Tran, Jimmy J Romero, Mayssa Zayat, Lenard M Lichtenberger

Faculty, Staff and Student Publications

Endotoxemia from sepsis can injure the gastrointestinal tract through mechanisms that have not been fully elucidated. We have shown that LPS induces an increase in gastric permeability in parallel with the luminal appearance of secretory phospholipase A2 (sPLA2) and its product, lysophosphatidylcholine (lyso-PC). We proposed that sPLA2 acted on the gastric hydrophobic barrier, composed primarily of phosphatidylcholine (PC), to degrade it and produce lyso-PC, an agent that is damaging to the mucosa. In the present study, we have tested whether lyso-PC and/or sPLA2 have direct damaging effects on the hydrophobic barriers of synthetic and mucosal surfaces. Rats were administered LPS …

Evidence For A Role Of Endocannabinoids, Astrocytes And P38 Phosphorylation In The Resolution Of Postoperative Pain, Matthew S. Alkaitis, Carlos Solorzano, Russell P. Landry, Daniele Piomelli, Joyce A. Deleo, E. Alfonso Romero-Sandoval

Dartmouth Scholarship

Background: An alarming portion of patients develop persistent or chronic pain following surgical procedures, but the mechanisms underlying the transition from acute to chronic pain states are not fully understood. In general, endocannabinoids (ECBs) inhibit nociceptive processing by stimulating cannabinoid receptors type 1 (CB₁) and type 2 (CB₂). We have previously shown that intrathecal administration of a CB₂ receptor agonist reverses both surgical incision-induced behavioral hypersensitivity and associated over-expression of spinal glial markers. We therefore hypothesized that endocannabinoid signaling promotes the resolution of acute postoperative pain by modulating pro-inflammatory signaling in spinal cord glial cells. …

Reduction Of Sympathetic Activity Via Adrenal-Targeted Grk2 Gene Deletion Attenuates Heart Failure Progression And Improves Cardiac Function After Myocardial Infarction., Anastasios Lymperopoulos, Giuseppe Rengo, Erhe Gao, Steven N. Ebert, Gerald W. Dorn, Walter J. Koch

Department of Medicine Faculty Papers

Chronic heart failure (HF) is characterized by sympathetic overactivity and enhanced circulating catecholamines (CAs), which significantly increase HF morbidity and mortality. We recently reported that adrenal G protein-coupled receptor kinase 2 (GRK2) is up-regulated in chronic HF, leading to enhanced CA release via desensitization/down-regulation of the chromaffin cell alpha(2)-adrenergic receptors that normally inhibit CA secretion. We also showed that adrenal GRK2 inhibition decreases circulating CAs and improves cardiac inotropic reserve and function. Herein, we hypothesized that adrenal-targeted GRK2 gene deletion before the onset of HF might be beneficial by reducing sympathetic activation. To specifically delete GRK2 in the chromaffin cells …

Thoracic Aortic Disease In Tuberous Sclerosis Complex: Molecular Pathogenesis And Potential Therapies In Tsc2+/- Mice, Jiumei Cao, Limin Gong, Dong-Chuan Guo, Ulrike Mietzsch, Shao-Qing Kuang, Callie S Kwartler, Hazim Safi, Anthony Estrera, Michael J Gambello, Dianna M Milewicz

Faculty, Staff and Student Publications

Tuberous sclerosis complex (TSC) is a genetic disorder with pleiotropic manifestations caused by heterozygous mutations in either TSC1 or TSC2. One of the less investigated complications of TSC is the formation of aneurysms of the descending aorta, which are characterized on pathologic examination by smooth muscle cell (SMC) proliferation in the aortic media. SMCs were explanted from Tsc2(+/-) mice to investigate the pathogenesis of aortic aneurysms caused by TSC2 mutations. Tsc2(+/-) SMCs demonstrated increased phosphorylation of mammalian target of rapamycin (mTOR), S6 and p70S6K and increased proliferation rates compared with wild-type (WT) SMCs. Tsc2(+/-) SMCs also had reduced expression of …

Oas1 Polymorphisms Are Associated With Susceptibility To West Nile Encephalitis In Horses, Jonathan J. Rios, Joann G. W. Fleming, Uneeda K. Bryant, Craig N. Carter, John C. Huber Jr., Maureen T. Long, Thomas E. Spencer, David L. Adelson

Veterinary Diagnostic Laboratory Faculty Publications

West Nile virus, first identified within the United States in 1999, has since spread across the continental states and infected birds, humans and domestic animals, resulting in numerous deaths. Previous studies in mice identified the Oas1b gene, a member of the OAS/RNASEL innate immune system, as a determining factor for resistance to West Nile virus (WNV) infection. A recent case-control association study described mutations of human OAS1 associated with clinical susceptibility to WNV infection. Similar studies in horses, a particularly susceptible species, have been lacking, in part, because of the difficulty in collecting populations sufficiently homogenous in their infection and …

Individual Micrornas (Mirnas) Display Distinct Mrna Targeting "Rules", Wang-Xia Wang, Bernard R. Wilfred, Kevin Xie, Mary H. Jennings, Yanling Hu, Arnold J. Stromberg, Peter T. Nelson

Pathology and Laboratory Medicine Faculty Publications

MicroRNAs (miRNAs) guide Argonaute (AGO)-containing microribonucleoprotein (miRNP) complexes to target mRNAs.It has been assumed that miRNAs behave similarly to each other with regard to mRNA target recognition. The usual assumptions, which are based on prior studies, are that miRNAs target preferentially sequences in the 3'UTR of mRNAs,guided by the 5' "seed" portion of the miRNAs. Here we isolated AGO- and miRNA-containing miRNPs from human H4 tumor cells by co-immunoprecipitation (co-IP) with anti-AGO antibody. Cells were transfected with miR-107, miR-124,miR-128, miR-320, or a negative control miRNA. Co-IPed RNAs were subjected to downstream high-density Affymetrix Human Gene 1.0 ST microarray analyses using …

Perfusion In Rat Brain At 7 T With Arterial Spin Labeling Using Fair-Truefisp And Quipss, Emilio Esparza-Coss, Jarek Wosik, Ponnada A Narayana

Faculty, Staff and Student Publications

Measurement of perfusion in longitudinal studies allows for the assessment of tissue integrity and the detection of subtle pathologies. In this work, the feasibility of measuring brain perfusion in rats with high spatial resolution using arterial spin labeling is reported. A flow-sensitive alternating recovery sequence, coupled with a balanced gradient fast imaging with steady-state precession readout section was used to minimize ghosting and geometric distortions, while achieving high signal-to-noise ratio. The quantitative imaging of perfusion using a single subtraction method was implemented to address the effects of variable transit delays between the labeling of spins and their arrival at the …

Imaging Targeted-Agent Binding In Vivo With Two Probes, Brian W. Pogue, Kimberley S. Samkoe, Shannon Hextrum, Julia A. O'Hara, Michael Jermyn, Subhadra Srinivasan, Tayyaba Hasan

Dartmouth Scholarship

An approach to quantitatively image targeted-agent binding rate in vivo is demonstrated with dual-probe injection of both targeted and nontargeted fluorescent dyes. Images of a binding rate constant are created that reveal lower than expected uptake of epidermal growth factor in an orthotopic xenograft pancreas tumor (2.3×10−5 s−1), as compared to the normal pancreas (3.4×10−5 s−1). This approach allows noninvasive assessment of tumor receptor targeting in vivo to determine the expected contrast, spatial localization, and efficacy in therapeutic agent delivery.

Targeting therapeutic drugs to tumors based on their overexpression of cellular receptors is widely researched and has important clinical success. …

Effect Of Indomethacin On Bile Acid-Phospholipid Interactions: Implication For Small Intestinal Injury Induced By Nonsteroidal Anti-Inflammatory Drugs, Yong Zhou, Elizabeth J Dial, Rand Doyen, Lenard M Lichtenberger

Faculty, Staff and Student Publications

The injurious effect of nonsteroidal anti-inflammatory drugs (NSAIDs) in the small intestine was not appreciated until the widespread use of capsule endoscopy. Animal studies found that NSAID-induced small intestinal injury depends on the ability of these drugs to be secreted into the bile. Because the individual toxicity of amphiphilic bile acids and NSAIDs directly correlates with their interactions with phospholipid membranes, we propose that the presence of both NSAIDs and bile acids alters their individual physicochemical properties and enhances the disruptive effect on cell membranes and overall cytotoxicity. We utilized in vitro gastric AGS and intestinal IEC-6 cells and found …

Optimal Bone Strength And Mineralization Requires The Type 2 Iodothyronine Deiodinase In Osteoblasts, J. H. D. Bassett, Alan Boyde, Peter G. T. Howell, Richard H. Bassett, Thomas M. Galliford, Marta Archanco, Holly Evans, Michelle A. Lawson, Peter Croucher, Donald L. St. Germain, Valerie A. Galton, Graham R. Williams

Dartmouth Scholarship

Hypothyroidism and thyrotoxicosis are each associated with an increased risk of fracture. Although thyroxine (T4) is the predominant circulating thyroid hormone, target cell responses are determined by local intracellular availability of the active hormone 3,5,3'-L-triiodothyronine (T3), which is generated from T4 by the type 2 deiodinase enzyme (D2). To investigate the role of locally produced T3 in bone, we characterized mice deficient in D2 (D2KO) in which the serum T3 level is normal. Bones from adult D2KO mice have reduced toughness and are brittle, displaying an increased susceptibility to fracture. This phenotype is characterized by a 50% reduction in bone …

Whole-Genome Snp Association In The Horse: Identification Of A Deletion In Myosin Va Responsible For Lavender Foal Syndrome, Samantha A. Brooks, Nicole Gabreski, Donald Miller, Abra Brisbin, Helen E. Brown, Cassandra Streeter, Jason Mezey, Deborah Cook, Douglas F. Antczak

Veterinary Science Faculty Publications

Lavender Foal Syndrome (LFS) is a lethal inherited disease of horses with a suspected autosomal recessive mode of inheritance. LFS has been primarily diagnosed in a subgroup of the Arabian breed, the Egyptian Arabian horse. The condition is characterized by multiple neurological abnormalities and a dilute coat color. Candidate genes based on comparative phenotypes in mice and humans include the ras-associated protein RAB27a (RAB27A) and myosin Va (MYO5A). Here we report mapping of the locus responsible for LFS using a small set of 36 horses segregating for LFS. These horses were genotyped using a newly available single nucleotide polymorphism (SNP) …

Foxm1b Regulates Nedd4-1 Expression, Leading To Cellular Transformation And Full Malignant Phenotype In Immortalized Human Astrocytes, Bingbing Dai, Russell O Pieper, Dawei Li, Ping Wei, Mingguang Liu, Shiao Y Woo, Kenneth D Aldape, Raymond Sawaya, Keping Xie, Suyun Huang

Faculty, Staff and Student Publications

Our recent studies have shown that the FoxM1B transcription factor is overexpressed in human glioma tissues and that the level of its expression correlates directly with glioma grade. However, whether FoxM1B plays a role in the early development of glioma (i.e., in transformation) is unknown. In this study, we found that the FoxM1B molecule causes cellular transformation and tumor formation in normal human astrocytes (NHA) immortalized by p53 and pRB inhibition. Moreover, brain tumors that arose from intracranial injection of FoxM1B-expressing immortalized NHAs displayed glioblastoma multiforme (GBM) phenotypes, suggesting that FoxM1B overexpression in immortalized NHAs not only transforms the cells …

Role Of Flgt In Anchoring The Flagellum Of Vibrio Cholerae, Raquel M. Martinez, Brooke A. Jude, Thomas J. Kirn, Karen Skorupski, Ronald K. Taylor

Dartmouth Scholarship

Flagellar motility has long been regarded as an important virulence factor. In Vibrio cholerae, the single polar flagellum is essential for motility as well as for proper attachment and colonization. In this study, we demonstrate that the novel flagellar protein FlgT is involved in anchoring the flagellum to the V. cholerae cell. A screen for novel colonization factors by use of TnphoA mutagenesis identified flgT. An in-frame deletion of flgT established that FlgT is required for attachment, colonization, and motility. Transmission electron microscopy revealed that while the flgT mutant is capable of assembling a phenotypically normal flagellum, …

Loss Of Dna Polymerase Zeta Enhances Spontaneous Tumorigenesis, John P Wittschieben, Vaishali Patil, Veronika Glushets, Lisa J Robinson, Donna F Kusewitt, Richard D Wood

Faculty, Staff and Student Publications

Mammalian genomes encode at least 15 distinct DNA polymerases, functioning as specialists in DNA replication, DNA repair, recombination, or bypass of DNA damage. Although the DNA polymerase zeta (polzeta) catalytic subunit REV3L is important in defense against genotoxins, little is known of its biological function. This is because REV3L is essential during embryogenesis, unlike other translesion DNA polymerases. Outstanding questions include whether any adult cells are viable in the absence of polzeta and whether polzeta status influences tumorigenesis. REV3L-deficient cells have properties that could influence the development of neoplasia in opposing ways: markedly reduced damage-induced point mutagenesis and extensive chromosome …

Molecular Cross Talk Between Misfolded Proteins In Animal Models Of Alzheimer's And Prion Diseases, Rodrigo Morales, Lisbell D Estrada, Rodrigo Diaz-Espinoza, Diego Morales-Scheihing, Maria C Jara, Joaquin Castilla, Claudio Soto

Faculty, Staff and Student Publications

The central event in protein misfolding disorders (PMDs) is the accumulation of a misfolded form of a naturally expressed protein. Despite the diversity of clinical symptoms associated with different PMDs, many similarities in their mechanism suggest that distinct pathologies may cross talk at the molecular level. The main goal of this study was to analyze the interaction of the protein misfolding processes implicated in Alzheimer's and prion diseases. For this purpose, we inoculated prions in an Alzheimer's transgenic mouse model that develop typical amyloid plaques and followed the progression of pathological changes over time. Our findings show a dramatic acceleration …

Synthesis, Biological Evaluation, And Molecular Modeling Studies Of 1-Aryl-1h-Pyrazole-Fused Curcumin Analogues As Anticancer Agents, L Curtis, P Datta, X Liu, N Bogdanova, R Heidelberger, R Janz

Faculty, Staff and Student Publications

Ribbon synapses of the vertebrate retina are specialized synapses that release neurotransmitter by synaptic vesicle exocytosis in a manner that is proportional to the level of depolarization of the cell. This release property is different from conventional neurons, in which the release of neurotransmitter occurs as a short-lived burst triggered by an action potential. Synaptic vesicle exocytosis is a calcium regulated process that is dependent on a set of interacting synaptic proteins that form the so-called SNARE (soluble N-ethylmaleimide sensitive factor attachment protein receptor) complex. Syntaxin 3B has been identified as a specialized SNARE molecule in ribbon synapses of the …

Motor Output Evoked By Subsaccadic Stimulation Of Primate Frontal Eye Fields., Brian D Corneil, James K Elsley, Benjamin Nagy, Sharon L Cushing

Brain and Mind Institute Researchers' Publications

In addition to its role in shifting the line of sight, the oculomotor system is also involved in the covert orienting of visuospatial attention. Causal evidence supporting this premotor theory of attention, or oculomotor readiness hypothesis, comes from the effect of subsaccadic threshold stimulation of the oculomotor system on behavior and neural activity in the absence of evoked saccades, which parallels the effects of covert attention. Here, by recording neck-muscle activity from monkeys and systematically titrating the level of stimulation current delivered to the frontal eye fields (FEF), we show that such subsaccadic stimulation is not divorced from immediate motor …

Neuropilin 1 Directly Interacts With Fer Kinase To Mediate Semaphorin3a-Induced Death Of Cortical Neurons, Susan X. Jiang, Shawn N. Whitehead, Amy Aylsworth, Bogdan Zurakowski, Kenneth Chan, Jianjun Li, Sheng T. Hou

Anatomy and Cell Biology Publications

Neuropilins (NRPs) are receptors for the major chemorepulsive axonal guidance cue semaphorins (Sema). The interaction of Sema3A/NRP1 during development leads to the collapse of growth cones. Here we show that Sema3A also induces death of cultured cortical neurons through NRP1. A specific NRP1 inhibitory peptide ameliorated Sema3A-evoked cortical axonal retraction and neuronal death. Moreover, Sema3A was also involved in cerebral ischemia-induced neuronal death. Expression levels of Sema3A and NRP1, but not NRP2, were significantly increased early during brain reperfusion following transient focal cerebral ischemia. NRP1 inhibitory peptide delivered to the ischemic brain was potently neuroprotective and prevented the loss of …

Efficient Activation Of Reconstructed Rat Embryos By Cyclin-Dependent Kinase Inhibitors, Robin L. Webb, Kirk A. Findlay, Michael A. Green, Tina L. Beckett, M. Paul Murphy

Molecular and Cellular Biochemistry Faculty Publications

Background

Over the last decade a number of species, from farm animals to rodents, have been cloned using somatic cell nuclear transfer technology (SCNT). This technique has the potential to revolutionize the way that genetically modified animals are made. In its current state, the process of SCNT is very inefficient (<5% success rate), with several technical and biological hurdles hindering development. Yet, SCNT provides investigators with powerful advantages over other approaches, such as allowing for prescreening for the desired level of transgene expression and eliminating the excess production of undesirable wild-type animals. The rat plays a significant role in biomedical research, but SCNT has been problematic for this species. In this study, we address one aspect of the problem by evaluating methods of activation in artificially constructed rat embryos.

Principal Findings

We demonstrate that treatment with a calcium ionophore (ionomycin) combined with a variety of cyclin-dependent kinase inhibitors is an effective way to activate rat embryos. This is in contrast to methods developed for the mouse embryo, which tolerates much less specific chemical treatments. Methods developed to activate …

Dopamine Neuron Stimulating Actions Of A Gdnf Propeptide, Luke H. Bradley, Josh Fuqua, April Richardson, Jadwiga Turchan-Cholewo, Yi Ai, Kristen A. Kelps, John D. Glass, Xiuquan He, Zhiming Zhang, Richard Grondin, O. Meagan Littrell, Peter Huettl, Francois Pomerleau, Don M. Gash, Greg A. Gerhardt

Neuroscience Faculty Publications

BACKGROUND: Neurotrophic factors, such as glial cell line-derived neurotrophic factor (GDNF), have shown great promise for protection and restoration of damaged or dying dopamine neurons in animal models and in some Parkinson's disease (PD) clinical trials. However, the delivery of neurotrophic factors to the brain is difficult due to their large size and poor bio-distribution. In addition, developing more efficacious trophic factors is hampered by the difficulty of synthesis and structural modification. Small molecules with neurotrophic actions that are easy to synthesize and modify to improve bioavailability are needed.

METHODS AND FINDINGS: Here we present the neurobiological actions of dopamine …

Eicosapentaenoic Acid Preserves Diaphragm Force Generation Following Endotoxin Administration, Gerald S. Supinski, Jonas Vanags, Leigh Ann Callahan

Internal Medicine Faculty Publications

INTRODUCTION: Infections produce severe respiratory muscle weakness, which contributes to the development of respiratory failure. An effective, safe therapy to prevent respiratory muscle dysfunction in infected patients has not been defined. This study examined the effect of eicosapentaenoic acid (EPA), an immunomodulator that can be safely administered to patients, on diaphragm force generation following endotoxin administration.

METHODS: Rats were administered the following (n = 5/group): (a) saline, (b) endotoxin, 12 mg/kg IP, (c) endotoxin + EPA (1.0 g/kg/d), and (d) EPA alone. Diaphragms were removed and measurements made of the diaphragm force-frequency curve, calpain activation, caspase activation, and protein carbonyl …

Erk1/2-Akt1 Crosstalk Regulates Arteriogenesis In Mice And Zebrafish, Bin Ren, Yong Deng, Arpita Mukhopadhyay, Anthony A. Lanahan, Zhen W. Zhuang, Karen L. Moodie, Mary Jo Mulligan-Kehoe, Tatiana V. Byzova, Randall T. Peterson, Michael Simons

Dartmouth Scholarship

Arterial morphogenesis is an important and poorly understood process. In particular, the signaling events controlling arterial formation have not been established. We evaluated whether alterations in the balance between ERK1/2 and PI3K signaling pathways could stimulate arterial formation in the setting of defective arterial morphogenesis in mice and zebrafish. Increased ERK1/2 activity in mouse ECs with reduced VEGF responsiveness was achieved in vitro and in vivo by downregulating PI3K activity, suppressing Akt1 but not Akt2 expression, or introducing a constitutively active ERK1/2 construct. Such restoration of ERK1/2 activation was sufficient to restore impaired arterial development and branching morphogenesis in synectin-deficient …

Microrna-31 Functions As An Oncogenic Microrna In Mouse And Human Lung Cancer Cells By Repressing Specific Tumor Suppressors, Xi Liu, Lorenzo F. Sempere, Haoxu Ouyang, Vincent A. Memoli, Angeline S. Andrew, Yue Luo, Eugene Demidenko, Murray Korc, Wei Shi, Meir Preis, Konstantin H. Dragnev, Hua Li, James Direnzo, Mads Bak, Sarah J. Freemantle, Sakari Kauppinen, Ethan Dmitrovsky

Dartmouth Scholarship

MicroRNAs (miRNAs) regulate gene expression. It has been suggested that obtaining miRNA expression profiles can improve classification, diagnostic, and prognostic information in oncology. Here, we sought to comprehensively identify the miRNAs that are overexpressed in lung cancer by conducting miRNA microarray expression profiling on normal lung versus adjacent lung cancers from transgenic mice. We found that miR-136, miR-376a, and miR-31 were each prominently overexpressed in murine lung cancers. Real-time RT-PCR and in situ hybridization (ISH) assays confirmed these miRNA expression profiles in paired normal-malignant lung tissues from mice and humans. Engineered knockdown of miR-31, but not other highlighted miRNAs, substantially …

Development And Validation Of A Rapid Method For The Detection Of Latrunculol A In Plasma., Jiajiu Shaw, Frederick A. Valeriote, Joseph Media, Tyler A. Johnson, Taro Amagata, Karen Tenney, Phillip Crews

Natural Sciences and Mathematics | Faculty Scholarship

Latrunculol A is a recently discovered 6,7-dihydroxy analog of the potent actin inhibitor latrunculin A. Latrunculol A has exhibited greater cytotoxicity than latrunculin A against both murine and human colon tumor cell lines in vitro. Currently, there are no reports regarding the bioavailability of latrunculol A in vivo. This study was undertaken as a prelude to pharmacokinetic assessments and it is the first work where bioavailability of latrunculol A was studied. In the present work, a simple plasma preparation and a rapid HPLC method have been developed. Mouse plasma containing latrunculol A was first treated by acetonitrile and then centrifuged …

P66shc--A Longevity Redox Protein In Human Prostate Cancer Progression And Metastasis : P66shc In Cancer Progression And Metastasis., Mythilypriya Rajendran, Paul Thomes, Li Zhang, Suresh Veeramani, Ming-Fong Lin

Journal Articles: Biochemistry & Molecular Biology

p66Shc, a 66 kDa proto-oncogene Src homologous-collagen homologue (Shc) adaptor protein, is classically known in mediating receptor tyrosine kinase signaling and recently identified as a sensor to oxidative stress-induced apoptosis and as a longevity protein in mammals. The expression of p66Shc is decreased in mice and increased in human fibroblasts upon aging and in aging-related diseases, including prostate cancer. p66Shc protein level correlates with the proliferation of several carcinoma cells and can be regulated by steroid hormones. Recent advances point that p66Shc protein plays a role in mediating cross-talk between steroid hormones and redox signals by serving as a common …

Cardiomyocyte-Derived Adiponectin Is Biologically Active In Protecting Against Myocardial Ischemia-Reperfusion Injury., Yajing Wang, Wayne Bond Lau, Erhe Gao, Ling Tao, Yuexing Yuan, Rong Li, Xiaoliang Wang, Walter J. Koch, Xin-Liang Ma

Department of Emergency Medicine Faculty Papers

Adiponectin (APN) has traditionally been viewed as an adipocyte-specific endocrine molecule with cardioprotective effects. Recent studies suggest that APN is also expressed in cardiomyocytes. However, biological significances of this locally produced APN remain completely unknown. The aim of this study was to investigate the pathological and pharmacological significance of cardiac-derived APN in cardiomyocyte pathology. Adult cardiomyocytes from wild-type littermates (WT) or gene-deficient mice were pretreated with vehicle (V) or rosiglitazone (RSG) for 6 h followed by simulated ischemia-reperfusion (SI/R, 3 h/12 h). Compared with WT cardiomyocytes, myocytes from APN knockout (APN-KO) mice sustained greater SI/R injury, evidenced by greater oxidative/nitrative …

Transgenic Rat Model Of Neurodegeneration Caused By Mutation In The Tdp Gene., Hongxia Zhou, Cao Huang, Han Chen, Dian Wang, Carlisle P Landel, Pedro Yuxing Xia, Robert Bowser, Yong-Jian Liu, Xu Gang Xia

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

TDP-43 proteinopathies have been observed in a wide range of neurodegenerative diseases. Mutations in the gene encoding TDP-43 (i.e., TDP) have been identified in amyotrophic lateral sclerosis (ALS) and in frontotemporal lobe degeneration associated with motor neuron disease. To study the consequences of TDP mutation in an intact system, we created transgenic rats expressing normal human TDP or a mutant form of human TDP with a M337V substitution. Overexpression of mutant, but not normal, TDP caused widespread neurodegeneration that predominantly affected the motor system. TDP mutation reproduced ALS phenotypes in transgenic rats, as seen by progressive degeneration of motor neurons …

Cardioprotection By Regular Ethanol Consumption: Potential Mechanisms And Clinical Application., Masami Miyamae, Kazuhiro Kaneda, Naochika Domae, Vincent M. Figueredo, M.D.

Division of Cardiology Faculty Papers

Epidemiological studies demonstrate that excessive drinking is associated with hypertension, cerebral bleeding and loss of cardiac contractility. Conversely, studies have shown that mortality rates for people who regularly drink ethanol in moderation are lower than in abstainers, primarily due to decreased fatal ischemic heart disease. Further, moderate ethanol consumers have lower rates of myocardial infarction compared with abstainers. These beneficial cardiac effects may be due to pleiotropic effects of ethanol on lipids, platelets, and fibrinolytic activity. During the past decade, studies conducted in several animal models have revealed that light to moderate regular ethanol consumption renders hearts more tolerant to …

Acat1 Gene Ablation Increases 24(S)-Hydroxycholesterol Content In The Brain And Ameliorates Amyloid Pathology In Mice With Ad, Elena Y. Bryleva, Maximillian A. Rogers, Catherine C. Y. Chang, Floyd Buen

Dartmouth Scholarship

Cholesterol metabolism has been implicated in the pathogenesis of several neurodegenerative diseases, including the abnormal accumulation of amyloid-beta, one of the pathological hallmarks of Alzheimer disease (AD). Acyl-CoA:cholesterol acyltransferases (ACAT1 and ACAT2) are two enzymes that convert free cholesterol to cholesteryl esters. ACAT inhibitors have recently emerged as promising drug candidates for AD therapy. However, how ACAT inhibitors act in the brain has so far remained unclear. Here we show that ACAT1 is the major functional isoenzyme in the mouse brain. ACAT1 gene ablation (A1-) in triple transgenic (i.e., 3XTg-AD) mice leads to more than 60% reduction in full-length human …

Deficient Cd40-Traf6 Signaling In Leukocytes Prevents Atherosclerosis By Skewing The Immune Response Toward An Antiinflammatory Profile, Esther Lutgens, Dirk Lievens, Linda Beckers, Erwin Wijnands, Oliver Soehnlein, Alma Zernecke, Tom Seijkens, David Engel, Jack Cleutjens, Anna M. Keller, Shalin H. Naike, Louis Boon, Hafid Ait Oufella, Ziad Mallat, Cory L. Ahonen, Randolph J. Noelle, Menno P. De Winther, Mat J. Daemen, Erik A. Biessen, Christian Weber

Dartmouth Scholarship

The CD40–CD40 ligand (CD40L) signaling axis plays an important role in immunological pathways. Consequently, this dyad is involved in chronic inflammatory diseases, including atherosclerosis. Inhibition of CD40L in apolipoprotein E (Apoe)–deficient ( Apoe - / - ) mice not only reduced atherosclerosis but also conferred a clinically favorable plaque phenotype that was low in inflammation and high in fibrosis. Blockade of CD40L may not be therapeutically feasible, as long-term inhibition will compromise systemic immune responses. Conceivably, more targeted intervention strategies in CD40 signaling will have less deleterious side effects. We report that deficiency in hematopoietic CD40 reduces atherosclerosis and induces …