Medicine and Health Sciences Commons^™

Mast Cells Modulate Acute Toxoplasmosis In Murine Models, Bo Huang, Shiguang Huang, Ying Chen, Huanqin Zheng, Jilong Shen, Zhao-Rong Lun, Yong Wang, Lloyd H. Kasper, Fangli Lu

Dartmouth Scholarship

The role of mast cells (MCs) in Toxoplasma gondii infection is poorly known. Kunming outbred mice were infected intraperitoneally with RH strain T. gondii, either treated with compound 48/80 (C48/80, MC activator) or disodium cromoglycate (DSCG, MC inhibitor). Compared with infected controls, infected mice treated with C48/80 exhibited significantly increased inflammation in the liver (P < 0.01), spleen (P < 0.05), and mesentery (P < 0.05) tissues, higher parasite burden in the peritoneal lavage fluids (P < 0.01), and increased levels of mRNA transcripts of T. gondii tachyzoite surface antigen 1 (SAG1) gene in the spleen and liver tissues (P < 0.01), accompanied with significantly increased Th1 cytokine (IFN-γ, IL-12p40, and TNF-α) (P < 0.01) and decreased IL-10 (P < 0.01) mRNA expressions in the liver, and increased IFN-γ (P < 0.01) and IL-12p40 (P < 0.01) but decreased TNF-α (P < 0.01) and IL-4 (P < 0.01) in the spleens of infected mice treated with C48/80 at day 9-10 p.i. Whereas mice treated with DSCG had significantly decreased tissue lesions (P < 0.01), lower parasite burden in the peritoneal lavage fluids (P < 0.01) and decreased SAG1 expressions in the spleen and liver tissues (P < 0.01), accompanied with significantly increased IFN-γ (P < 0.01) and IL-12p40 (P < 0.05) in the liver, and decreased IFN-γ (P < 0.05) and TNF-α (P < 0.01) in the spleens; IL-4 and IL-10 expressions in both the spleen and liver were significantly increased (P < 0.01) in the infected mice treated with DSCG. These findings suggest that mediators associated with the MC activation may play an important role in modulating acute inflammatory pathogenesis and parasite clearance during T. gondii infection in this strain of mice. Thus, MC …

Regulation Of Cell Death By Transfer Rna., Ya-Ming Hou, Xiaolu Yang

Department of Biochemistry and Molecular Biology Faculty Papers

SIGNIFICANCE: Both transfer RNA (tRNA) and cytochrome c are essential molecules for the survival of cells. tRNA decodes mRNA codons into amino-acid-building blocks in protein in all organisms, whereas cytochrome c functions in the electron transport chain that powers ATP synthesis in mitochondrion-containing eukaryotes. Additionally, in vertebrates, cytochrome c that is released from mitochondria is a potent inducer of apoptosis, activating apoptotic proteins (caspases) in the cytoplasm to dismantle cells. A better understanding of both tRNA and cytochrome c is essential for an insight into the regulation of cell life and death.

RECENT ADVANCES: A recent study showed that the …

A Common Human Beta Globin Splicing Mutation Modeled In Mice., J. Lewis, Baoli Yang, R. Kim, H. Sierakowska, R. Kole, O. Smithies, N. Maeda

Baoli Yang

The betaIVS-2-654 C-->T mutation accounts for approximately 20% of beta thalassemia mutations in southern China; it causes aberrant RNA splicing and leads to beta0 thalassemia. To provide an animal model for testing therapies for correcting splicing defects, we have used the "plug and socket" method of gene targeting in murine embryonic stem cells to replace the two (cis) murine adult beta globin genes with a single copy of the human betaIVS-2-654 gene. No homozygous mice survive postnatally. Heterozygous mice carrying this mutant gene produce reduced amounts of the mouse beta globin chains and no human beta globin, and have …

Regulation Of Terminal Deoxynucleotidyl Transferase Gene Expression In Mice And Men., M. Coleman, Baoli Yang, D. Sorscher

Baoli Yang

A nontemplate directed DNA polymerase, terminal deoxynucleotidyl transferase (terminal transferase) is expressed in a tissue-specific and development stage-specific manner. Its enzymatic properties and tissue localization have implicated the protein in development of normal immune function. Significant progress has been made in understanding the enzymology and important domains of this protein. More recently, studies have focused on regulation of the gene that codes for the protein in mice and humans. The murine gene has yielded to these studies more readily than the human gene. A murine basal promoter element has been identified along with several trans-acting protein factors that may regulate …

Tricarboxylic Acid Cycle And One-Carbon Metabolism Pathways Are Important In Edwardsiella Ictaluri Virulence., Neeti Dahal, Hossam Abdelhamed, Jingjun Lu, Attila Karsi, Mark L. Lawrence

College of Veterinary Medicine Publications and Scholarship

Edwardsiella ictaluri is a Gram-negative facultative intracellular pathogen causing enteric septicemia of channel catfish (ESC). The disease causes considerable economic losses in the commercial catfish industry in the United States. Although antibiotics are used as feed additive, vaccination is a better alternative for prevention of the disease. Here we report the development and characterization of novel live attenuated E. ictaluri mutants. To accomplish this, several tricarboxylic acid cycle (sdhC, mdh, and frdA) and one-carbon metabolism genes (gcvP and glyA) were deleted in wild type E. ictaluri strain 93-146 by allelic exchange. Following bioluminescence tagging of the E. ictaluri ?sdhC, ?mdh, …

Genetic And Non-Genetic Predictors Of Line-1 Methylation In Leukocyte Dna, Salman M. Tajuddin, Andre F.S. Amaral, Agustín F. Fernández, Sandra Rodríguez-Rodero, Ramon Maria Rodriguez, Lee E. Moore, Adonina Tardon, Alfredo Carrato, Montserrat Garcia-Closas, Debra T. Silverman, Brian P. Jackson

Dartmouth Scholarship

Background: Altered DNA methylation has been associated with various diseases.

Objective: We evaluated the association between levels of methylation in leukocyte DNA at long interspersed nuclear element 1 (LINE-1) and genetic and non-genetic characteristics of 892 control participants from the Spanish Bladder Cancer/EPICURO study.

Methods: We determined LINE-1 methylation levels by pyrosequencing. Individual data included demographics, smoking status, nutrient intake, toenail concentrations of 12 trace elements, xenobiotic metabolism gene variants, and 515 polymorphisms among 24 genes in the one-carbon metabolism pathway. To assess the association between LINE-1 methylation levels (percentage of methylated cytosines) and potential determinants, we estimated beta coefficients …

Evidence For Tankyrases As Antineoplastic Targets In Lung Cancer, Alexander M. Busch, Kevin C. Johnson, Radu V. Stan, Aarti Sanglikar, Yashi Ahmed, Ethan Dmitrovsky, Sarah J. Freemantle

Dartmouth Scholarship

Background: New pharmacologic targets are urgently needed to treat or prevent lung cancer, the most common cause of cancer death for men and women. This study identified one such target. This is the canonical Wnt signaling pathway, which is deregulated in cancers, including those lacking adenomatous polyposis coli or β -catenin mutations. Two poly-ADP-ribose polymerase (PARP) enzymes regulate canonical Wnt activity: tankyrase (TNKS) 1 and TNKS2. These enzymes poly-ADP-ribosylate (PARsylate) and destabilize axin, a key component of the β -catenin phosphorylation complex. Methods: This study used comprehensive gene profiles to uncover deregulation of the Wnt pathway in murine transgenic and …

Pilot Study Of Cyp2b6 Genetic Variation To Explore The Contribution Of Nitrosamine Activation To Lung Carcinogenesis, Catherine Wassenaar, Qiong Dong, Christopher Amos, Margaret Spitz, Rachel F. Tyndale

Dartmouth Scholarship

We explored the contribution of nitrosamine metabolism to lung cancer in a pilot investigation of genetic variation in CYP2B6, a high-affinity enzymatic activator of tobacco-specific nitrosamines with a negligible role in nicotine metabolism. Previously we found that variation in CYP2A6 and CHRNA5-CHRNA3-CHRNB4 combined to increase lung cancer risk in a case-control study in European American ever-smokers (n = 860). However, these genes are involved in the pharmacology of both nicotine, through which they alter smoking behaviours, and carcinogenic nitrosamines. Herein, we separated participants by CYP2B6 genotype into a high- vs. low-risk group (*1/*1 + *1/*6 vs. *6/*6). Odds ratios estimated …

Data Mining The Functional Characterizations Of Proteins To Predict Their Cancer-Relatedness, Peter Revesz, Christopher Assi

School of Computing: Faculty Publications

This paper considers two types of protein data. First, data about protein function described in a number of ways, such as, GO terms and PFAM families. Second, data about whether individual proteins are experimentally associated with cancer by an anomalous elevation or lowering of their expressions within cancerous cells. We combine these two types of protein data and test whether the first type of data, that is, the functional descriptors, can predict the second type of data, that is, cancer-relatedness. By using data mining and machine learning, we derive a classifier algorithm that using only GO term and PFAM family …

Linkage Of Two Human Pregnancy-Specific Beta 1-Glycoprotein Genes: One Is Associated With Hydatidiform Mole., Kimberly Leslie, S. Watanabe, K. Lei, D. Chou, C. Plouzek, H. Deng, J. Torres, J. Chou

Kimberly K. Leslie

A genomic clone containing two linked human pregnancy-specific beta 1-glycoprotein (PS beta G) genes has been isolated and characterized. The two genes are arranged in the same 5'----3' orientation; the 3' region (including the A2 and B-C exons) of the upstream gene, PSGGA, is linked to the 5' region (including the 5'/L and L/N exons) of PSGGB, the downstream gene. Depending upon the domains compared, PSGGA and PSGGB share 92-98% nucleotide and 86-95% amino acid sequence identity with PSG93, the most abundant PS beta G transcript. The 3' exon (B-C) of PSGGA contains four alternative splice sites and three polyadenylylation …

Identification Of Proteins Within The Nuclear Factor-Kappa B Transcriptional Complex Including Estrogen Receptor-Alpha, I. Feldman, G. Feldman, C. Mobarak, J. Dunkelberg, Kimberly Leslie

Kimberly K. Leslie

OBJECTIVE: The objective of the study was to determine whether cross-talk occurs between estrogen receptors (ERs) and nuclear factor-kappa-B (NF-kappaB), to assess the functional consequences of such an ER/NF-kappaB interaction, and to identify other unknown regulatory proteins that may participate in the NF-kappaB transcriptional complex. STUDY DESIGN: Electromobility gel shifts, reporter gene assays, and mass spectrometry were used to identify proteins interacting with the NF-kappaB deoxyribonucleic acid (DNA) response element. RESULTS: ER and the p65 subunit of NF-kappaB colocalized on DNA. This interaction was inhibitory for ER transcriptional activity. Sequencing of proteins bound to the NF-kappaB/DNA complex identified DNA-modifying enzymes, …

Models Representing Type I And Type Ii Human Endometrial Cancers: Ishikawa H And Hec50co Cells, L. Albitar, G. Pickett, M. Morgan, S. Davies, Kimberly Leslie

Kimberly K. Leslie

OBJECTIVE: Endometrial cancer models are critical to the advancement of investigation, and Ishikawa H and Hec50co cells have been used as research tools. The purpose of these studies is to verify the degree to which these commonly used cell models share the molecular characteristics of the two major in vivo endometrial cancer subtypes, I and II. METHODS: The studies reported include an analysis of pathologic features, tumor suppressor mutations, detailed karyotyping, and cell cycle regulation. RESULTS: Ishikawa H cells are hormone responsive and have lost PTEN expression. In addition they have lost RB1 expression due to a deletion in exon …

Consequences Of The Loss Of P53, Rb1, And Pten: Relationship To Gefitinib Resistance In Endometrial Cancer, L. Albitar, M. Carter, S. Davies, Kimberly Leslie

Kimberly K. Leslie

OBJECTIVE: These studies demonstrate how loss of function mutations or downregulation of key tumor suppressors missing from type I and type II endometrial cancer cells contributes to carcinogenesis and to resistance to the EGFR inhibitor gefitinib (ZD1839). METHODS: Cell models devoid of tumor suppressors PTEN and RB1 or PTEN were studied. PTEN, RB1 and p53 expression was reinstated, and the effects on cell cycle, apoptosis, and cell cycle regulators were evaluated. RESULTS: In Ishikawa H cells that model type I endometrial cancer in the loss of PTEN and RB1, re-expressing PTEN and RB1 increased the apoptotic and G1 phases and …

Long-Term Upregulation Of Inflammation And Suppression Of Cell Proliferation In The Brain Of Adult Rats Exposed To Traumatic Brain Injury Using The Controlled Cortical Impact Model, Sandra A. Acosta, Naoki Tajiri, Kazutaka Shinozuka, Hiroto Ishikawa, Bethany Grimmig, David M. Diamond, Paul R. Sanberg, Paula C. Bickford, Yuji Kaneko, Cesario V. Borlongan

Psychology Faculty Publications

The long-term consequences of traumatic brain injury (TBI), specifically the detrimental effects of inflammation on the neurogenic niches, are not very well understood. In the present in vivo study, we examined the prolonged pathological outcomes of experimental TBI in different parts of the rat brain with special emphasis on inflammation and neurogenesis. Sixty days after moderate controlled cortical impact injury, adult Sprague-Dawley male rats were euthanized and brain tissues harvested. Antibodies against the activated microglial marker, OX6, the cell cycle-regulating protein marker, Ki67, and the immature neuronal marker, doublecortin, DCX, were used to estimate microglial activation, cell proliferation, and neuronal …

Generation Of Hydrogen Peroxide-Resistant Murine Neuroblastoma Cells: A Target Discovery Platform For Novel Neuroprotective Genes, Annette E. Maczurek, Rebekka Wild, Daunia Laurenti, Megan L. Steele, Lezanne Ooi, Gerald Munch

Faculty of Science, Medicine and Health - Papers: part A

Oxidative stress has been suggested to play an important role in the pathogenesis of various neurodegenerative diseases including Alzheimer’s disease (AD). Hydrogen peroxide (H2O2), one of the main reactive oxygen species, is converted into the highly toxic ·OH radical in the presence of redox-active transition metals, which then oxidises nucleic acids, lipids and proteins, leading to neurodegeneration and cell death. There is an urgent need to gain more knowledge about relevant therapeutic targets to combat oxidative stress and it neurotoxic effects, and how this knowledge can be utilized to develop novel neuroprotective therapies for AD. One way to identify new …

Genetics Of Non-Syndromic Autosomal Recessive Mental Retardation, Bushra Afroze, Bushra Chaudhry

Department of Biological & Biomedical Sciences

Non-syndromic mental retardation is one of the most serious neurodevelopmental disorders, which has a serious impact not only on the affected individuals and their families but also on the health care system and society. Previously research has been more focused on the X-linked mental retardation and only recently studies have shown that non-syndromic autosomal recessive mental retardation is extremely heterogeneous and contributes much more than the X-linked mental retardation. But very little is known about the genes and loci involved in nonsyndromic autosomal recessive mental retardation than the X-linked mental retardation. To date only thirty loci and ten genes have …

Ash2 Acts As An Ecdysone Receptor Coactivator By Stabilizing The Histone Methyltransferase Trr., Albert Carbonell, Alexander Mazo, Florenci Serras, Montserrat Corominas

Department of Biochemistry and Molecular Biology Faculty Papers

The molting hormone ecdysone triggers chromatin changes via histone modifications that are important for gene regulation. On hormone activation, the ecdysone receptor (EcR) binds to the SET domain-containing histone H3 methyltransferase trithorax-related protein (Trr). Methylation of histone H3 at lysine 4 (H3K4me), which is associated with transcriptional activation, requires several cofactors, including Ash2. We find that ash2 mutants have severe defects in pupariation and metamorphosis due to a lack of activation of ecdysone-responsive genes. This transcriptional defect is caused by the absence of the H3K4me3 marks set by Trr in these genes. We present evidence that Ash2 interacts with Trr …