Life Sciences Commons^™

Maturation Requirements For Dendritic Cells In T Cell Stimulation Leading To Tolerance Versus Immunity, Helen O'Neill, Jonathan Tan

Jonathan Tan

The model that dendritic cell (DC) "maturation" describes the change from an immature, antigen-capturing cell to a mature, antigen-presenting cell is well-established. Classification of DCs in terms of function has been problematic previously. It is therefore proposed that mature and not immature DCs are responsible for antigen presentation and stimulation of T cells. Furthermore, DC antigen presentation to T cells can have two outcomes: tolerance or immunity. The particular outcomes appear to be determined by the activation state of the mature DC. DCs can be activated by a range of environmental stimuli or "danger signals". Here, the hypothesis is advanced …

Genetic And Molecular Analysis Of Phytochromes From The Filamentous Fungus Neurospora Crassa, Allan C. Froehlich, Bosl Noh, Richard D. Vierstra, Jennifer Loros, Jay C. Dunlap

Dartmouth Scholarship

Phytochromes (Phys) comprise a superfamily of red-/far-red-light-sensing proteins. Whereas higher-plant Phys that control numerous growth and developmental processes have been well described, the biochemical characteristics and functions of the microbial forms are largely unknown. Here, we describe analyses of the expression, regulation, and activities of two Phys in the filamentous fungus Neurospora crassa. In addition to containing the signature N-terminal domain predicted to covalently associate with a bilin chromophore, PHY-1 and PHY-2 contain C-terminal histidine kinase and response regulator motifs, implying that they function as hybrid two-component sensor kinases activated by light. A bacterially expressed N-terminal fragment of PHY-2 covalently …

A Ciliary Sensation: Mapping Components Of The Gtp Signaling Pathway, Heather G. Kuruvilla

Science and Mathematics Faculty Presentations

GTP is a chemorepellent in Tetrahymena thermophila, causing cells to exhibit avoidance behavior, characterized by ciliary reversal. Recent work in our laboratory has shown that tyrosine kinase activity is required in order for GTP signaling to take place (Bartholomew et al., submitted for publication). Second messengers which we have found to be important for GTP signaling in Tetrahymena include nitric oxide and cGMP. Previous studies by Kim et al., 1999, have shown that a calcium-based depolarization is elicited by the application of extracellular GTP. Currently, our lab is addressing the question of where intracellular calcium is involved in the GTP …

The Caenorhabditis Elegans Heterochronic Regulator Lin-14 Is A Novel Transcription Factor That Controls The Developmental Timing Of Transcription From The Insulin/Insulin-Like Growth Factor Gene Ins-33 By Direct Dna Binding., Marta Hristova, Darcy Birse, Yang Hong, Victor R. Ambros

Victor R. Ambros

A temporal gradient of the novel nuclear protein LIN-14 specifies the timing and sequence of stage-specific developmental events in Caenorhabditis elegans. The profound effects of lin-14 mutations on worm development suggest that LIN-14 directly or indirectly regulates stage-specific gene expression. We show that LIN-14 can associate with chromatin in vivo and has in vitro DNA binding activity. A bacterially expressed C-terminal domain of LIN-14 was used to select DNA sequences that contain a putative consensus binding site from a pool of randomized double-stranded oligonucleotides. To identify candidates for genes directly regulated by lin-14, we employed DNA microarray hybridization to compare …

Developmental Biology. Encountering Micrornas In Cell Fate Signaling., Xantha Karp, Victor Ambros

Victor R. Ambros

Comment on: LIN-12/Notch activation leads to microRNA-mediated down-regulation of Vav in C. elegans. [Science. 2005]

Growth Factor–Induced Shedding Of Syndecan-1 Confers Glypican-1 Dependence On Mitogenic Responses Of Cancer Cells, Kan Ding, Martha Lopez-Burks, José A. Sánchez-Duran, Murray Korc, Arthur D. Lander

Dartmouth Scholarship

The cell surface heparan sulfate proteoglycan (HSPG) glypican-1 is up-regulated by pancreatic and breast cancer cells, and its removal renders such cells insensitive to many growth factors. We sought to explain why the cell surface HSPG syndecan-1, which is also up-regulated by these cells and is a known growth factor coreceptor, does not compensate for glypican-1 loss. We show that the initial responses of these cells to the growth factor FGF2 are not glypican dependent, but they become so over time as FGF2 induces shedding of syndecan-1. Manipulations that retain syndecan-1 on the cell surface make long-term FGF2 responses glypican …

Silencing Of Retrotransposons In Dictyostelium By Dna Methylation And Rnai., Markus Kuhlmann, Branimira E. Borisova, Markus Kaller, Pontus Larsson, Dirk Stach, Jianbo Na, Ludwig Eichinger, Frank Lyko, Victor R. Ambros, Fredrik Soderbom, Christian Hammann, Wolfgang Nellen

Victor R. Ambros

We have identified a DNA methyltransferase of the Dnmt2 family in Dictyostelium that was denominated DnmA. Expression of the dnmA gene is downregulated during the developmental cycle. Overall DNA methylation in Dictyostelium is approximately 0.2% of the cytosine residues, which indicates its restriction to a limited set of genomic loci. Bisulfite sequencing of specific sites revealed that DnmA is responsible for methylation of mostly asymmetric C-residues in the retrotransposons DIRS-1 and Skipper. Disruption of the gene resulted in a loss of methylation and in increased transcription and mobilization of Skipper. Skipper transcription was also upregulated in strains that had genes …

Oral Contraceptive Use And Risk Of Breast Cancer Among Women With A Family History Of Breast Cancer: A Prospective Cohort Study, Stephanie A. Navarro Silvera, Anthony B. Miller, Thomas E. Rohan

Department of Public Health Scholarship and Creative Works

Family history of breast cancer is an established risk factor for breast cancer. In addition, there is evidence that oral contraceptive use may be associated with a moderate increase in breast cancer risk. The three cohort studies that have investigated the relationship between oral contraceptive use and breast cancer risk among women with a family history of breast cancer have yielded mixed results, possibly due to the relatively small sample sizes employed and/or differences in the selection of covariates for inclusion in multivariate models. Therefore, we examined the association between oral contraceptive use and breast cancer risk in a large …

Empirical Analysis Of The Str Profiles Resulting From Conceptual Mixtures, David R. Paoletti, Travis E. Doom, Carissa M. Krane, Michael L. Raymer, Dan E. Krane

Biology Faculty Publications

Samples containing DNA from two or more individuals can be difficult to interpret. Even ascertaining the number of contributors can be challenging and associated uncertainties can have dramatic effects on the interpretation of testing results. Using an FBI genotypes dataset, containing complete genotype information from the 13 Combined DNA Index System (CODIS) loci for 959 individuals, all possible mixtures of three individuals were exhaustively and empirically computed. Allele sharing between pairs of individuals in the original dataset, a randomized dataset and datasets of generated cousins and siblings was evaluated as were the number of loci that were necessary to reliably …

Influences Of Dietary Soy Isoflavones On Metabolism But Not Nociception And Stress Hormone Responses In Ovariectomized Female Rats, Edwin D. Lephart, Lihong H. Bu, Kenneth Setchell

Faculty Publications

Isoflavones, the most abundant phytoestrogens in soy foods, are structurally similar to 17beta-estradiol. Few studies have examined the nociception and stress hormone responses after consumption of soy isoflavones. Methods: In this study, ovariectomized (OVX) female Long-Evans rats were fed either an isoflavone-rich diet (Phyto-600) or an isoflavone-free diet (Phyto-free). We examined the effects of soy isoflavones on metabolism by measuring body weights, food/water intake, adipose tissue weights as well as serum leptin levels. Also, circulating isoflavone levels were quantified. During chemically induced estrous, nociceptive thresholds were recorded. Then, the animals were subjected to a stressor and stress hormone levels were …

Cigarette Smoking And Risk Of Glioma: A Prospective Cohort Study, Stephanie A. Navarro Silvera, Anthony B. Miller, Thomas E. Rohan

Department of Public Health Scholarship and Creative Works

The etiology of glioma, the most commonly diagnosed malignant brain tumor among adults in the United States, is poorly understood. N‐nitroso compounds are known carcinogens, which are found in cigarette smoke and can induce gliomas in rats. On this basis, it has been hypothesized that cigarette smoking may be associated with an increased risk of glioma. We investigated the association between cigarette smoking and glioma risk in the National Breast Screening Study, which included 89,835 Canadian women aged 40–59 years at recruitment between 1980 and 1985. Linkages to national cancer and mortality databases yielded data on cancer incidence and deaths …

Chromosomal Localization Of The Islet Neogenesis Associated Protein (Ingap) Gene In Syrian Hamster By Tyramide Signal Amplification-Fluorescence In Situ Hybridization (Tsa-Fish), Sallie A. Smith

Biological Sciences Theses & Dissertations

Diabetes mellitus is a group of conditions characterized by hyperglycemia due to an inability to produce or properly utilize insulin. The majority of cases fall into two categories, Type I and Type 2. Type I results from the autoimmune destruction of pancreatic β-cells of the islets. The beta cells are the exclusive source of insulin and the patient becomes entirely dependent on exogenous insulin to survive. Patients with Type 2 are distinguished by insulin resistance, a condition that develops due to the inability of the body to effectively use the insulin being produced. The β-cells gradually lose their ability to …

Mesodermally Expressed Drosophila Microrna-1 Is Regulated By Twist And Is Required In Muscles During Larval Growth., Nicholas S. Sokol, Victor R. Ambros

Victor R. Ambros

Although hundreds of evolutionarily conserved microRNAs have been discovered, the functions of most remain unknown. Here, we describe the embryonic spatiotemporal expression profile, transcriptional regulation, and loss-of-function phenotype of Drosophila miR-1 (DmiR-1). DmiR-1 RNA is highly expressed throughout the mesoderm of early embryos and subsequently in somatic, visceral, and pharyngeal muscles, and the dorsal vessel. The expression of DmiR-1 is controlled by the Twist and Mef2 transcription factors. DmiR-1KO mutants, generated using ends-in gene targeting, die as small, immobilized second instar larvae with severely deformed musculature. This lethality is rescued when a DmiR-1 transgene is expressed specifically in the mesoderm …

Graduate Colloquium, Borbala Mazzag

Borbala Mazzag

No abstract provided.

Atypical Pkciota Contributes To Poor Prognosis Through Loss Of Apical-Basal Polarity And Cyclin E Overexpression In Ovarian Cancer, Astrid M. Eder, Xiaomei Sui, Daniel G. Rosen, Laura K. Nolden, Kwai Wa Cheng, John P. Lahad, Madhuri Kango-Singh, Karen H. Lu, Carla L. Warneke, Edward N. Atkinson, Isabelle Bedrosian, Khandan Keyomarsi, Wen-Lin Kuo, Joe W. Gray, Jerry C. P. Yin, Jinsong Liu, Georg Halder, Gordon B. Mills

Biology Faculty Publications

We show that atypical PKCι, which plays a critical role in the establishment and maintenance of epithelial cell polarity, is genomically amplified and overexpressed in serous epithelial ovarian cancers. Furthermore, PKCι protein is markedly increased or mislocalized in all serous ovarian cancers. An increased PKCι DNA copy number is associated with decreased progression-free survival in serous epithelial ovarian cancers. In a Drosophila in vivo epithelial tissue model, overexpression of persistently active atypical PKC results in defects in apical-basal polarity, increased Cyclin E protein expression, and increased proliferation. Similar to the Drosophila model, increased PKCι proteins levels are associated with …

Expression Of G-Protein Inwardly Rectifying Potassium Channels (Girks) In Lung Cancer Cell Lines, Howard Plummer 3rd, Madhu Dhar, Maria Cekanova Ms, Rndr, Phd, Hildegard Schuller

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

BACKGROUND: Previous data from our laboratory has indicated that there is a functional link between the beta-adrenergic receptor signaling pathway and the G-protein inwardly rectifying potassium channel (GIRK1) in human breast cancer cell lines. We wanted to determine if GIRK channels were expressed in lung cancers and if a similar link exists in lung cancer. METHODS: GIRK1-4 expression and levels were determined by reverse transcription polymerase chain reaction (RT-PCR) and real-time PCR. GIRK protein levels were determined by western blots and cell proliferation was determined by a 5-bromo-2'-deoxyuridine (BrdU) assay. RESULTS: GIRK1 mRNA was expressed in three of six small …

Expression Of G-Protein Inwardly Rectifying Potassium Channels (Girks) In Lung Cancer Cell Lines, Howard Plummer 3rd, Madhu Dhar, Maria Cekanova Ms, Rndr, Phd, Hildegard Schuller

Maria Cekanova MS, RNDr, PhD

BACKGROUND: Previous data from our laboratory has indicated that there is a functional link between the beta-adrenergic receptor signaling pathway and the G-protein inwardly rectifying potassium channel (GIRK1) in human breast cancer cell lines. We wanted to determine if GIRK channels were expressed in lung cancers and if a similar link exists in lung cancer. METHODS: GIRK1-4 expression and levels were determined by reverse transcription polymerase chain reaction (RT-PCR) and real-time PCR. GIRK protein levels were determined by western blots and cell proliferation was determined by a 5-bromo-2'-deoxyuridine (BrdU) assay. RESULTS: GIRK1 mRNA was expressed in three of six small …

Group 13 Hox Proteins Interact With The Mh2 Domain Of R-Smads And Modulate Smad Transcriptional Activation Functions Independent Of Hox Dna Binding Capability, Thomas M. Williams, Melissa E. Williams, Joanne H. Heaton, Thomas D. Gelehrter, Jeffrey W. Innis

Biology Faculty Publications

Interactions with co-factors provide a means by which HOX proteins exert specificity. To identify candidate protein interactors of HOXA13, we created and screened an E11.5–E12.5, distal limb bud yeast two-hybrid prey library. Among the interactors, we isolated the BMP-signaling effector Smad5, which interacted with the paralogous HOXD13 but not with HOXA11 or HOXA9, revealing unique interaction capabilities of the AbdB-like HOX proteins. Using deletion mutants, we determined that the MH2 domain of Smad5 is necessary for HOXA13 interaction.

This is the first report demonstrating an interaction between HOX proteins and the MH2 domain of Smad proteins. HOXA13 and HOXD13 …

Calmodulin And Pf6 Are Components Of A Complex That Localizes To The C1 Microtubule Of The Flagellar Central Apparatus, Matthew J. Wargo, Erin E. Dymek, Elizabeth F. Smith

Dartmouth Scholarship

Studies of flagellar motility in Chlamydomonas mutants lacking specific central apparatus components have supported the hypothesis that the inherent asymmetry of this structure provides important spatial cues for asymmetric regulation of dynein activity. These studies have also suggested that specific projections associated with the C1 and C2 central tubules make unique contributions to modulating motility; yet, we still do not know the identities of most polypeptides associated with the central tubules. To identify components of the C1a projection, we took an immunoprecipitation approach using antibodies generated against PF6. The pf6 mutant lacks the C1a projection and possesses flagella that only …

Neonatal Brain: Regional Variability Of In Vivo Mr Imaging Relaxation Rates At 3.0 T-Initial Experience, L. A. Williams, N. Gelman, P. A. Picot, D. S. Lee, J. R. Ewing, V. K. Han, R. T. Thompson

Anatomy and Cell Biology Publications

PURPOSE: To retrospectively investigate regional in vivo magnetic resonance,(MR). imaging transverse and longitudinal relaxation rates at 3.0 T in neonatal brain, the p relationship between these rates, and their potential use for gray matter (G),versus-M white matter (WM) tissue discrimination. MATERIALS AND METHODS: I Informed parental consent for performance of imaging procedures was obtained in each infant. Informed consent for retrospective image analysis was not required; ethics approval was obtained from institutional review board. At 3.0 T, R1 and R2 were measured in brain regions (frontal WM, posterior WM, periventricular WM, frontal GM, posterior GM, basal ganglia, and thalamus) in …

Glycemic Index, Glycemic Load, And Pancreatic Cancer Risk (Canada), Stephanie A. Navarro Silvera, Thomas E. Rohan, Meera Jain, Paul D. Terry, Geoffrey R. Howe, Anthony B. Miller

Department of Public Health Scholarship and Creative Works

There is some evidence that plasma insulin and post-load plasma glucose may be associated with the risk of pancreatic cancer. Glycemic index and glycemic load are measures, which allow the carbohydrate content of individual foods to be classified according to their postprandial glycemic effects and hence their effects on circulating insulin levels. Therefore, we examined pancreatic cancer risk in association with a glycemic index (GI), glycemic load (GL), and intake of dietary carbohydrate and sugar in a prospective cohort of 49,613 Canadian women enrolled in the National Breast Screening Study (NBSS) who completed a self-administered food frequency questionnaire between 1980 …

Glycemic Index, Glycemic Load, And Pancreatic Cancer Risk (Canada), Stephanie A. Navarro Silvera, Thomas E. Rohan, Meera Jain, Paul D. Terry, Geoffrey R. Howe, Anthony B. Miller

Department of Public Health Scholarship and Creative Works

There is some evidence that plasma insulin and post-load plasma glucose may be associated with the risk of pancreatic cancer. Glycemic index and glycemic load are measures, which allow the carbohydrate content of individual foods to be classified according to their postprandial glycemic effects and hence their effects on circulating insulin levels. Therefore, we examined pancreatic cancer risk in association with a glycemic index (GI), glycemic load (GL), and intake of dietary carbohydrate and sugar in a prospective cohort of 49,613 Canadian women enrolled in the National Breast Screening Study (NBSS) who completed a self-administered food frequency questionnaire between 1980 …

Myod Targets Chromatin Remodeling Complexes To The Myogenin Locus Prior To Forming A Stable Dna-Bound Complex, Ivana L. De La Serna, Yasuyuki Ohkawa, Charlotte A. Berkes, Donald A. Bergstrom, Caroline S. Dacwag, Stephen J. Tapscott, Anthony N. Imbalzano

Biology Faculty Publications

The activation of muscle-specific gene expression requires the coordinated action of muscle regulatory proteins and chromatin-remodeling enzymes. Microarray analysis performed in the presence or absence of a dominant-negative BRG1 ATPase demonstrated that approximately one-third of MyoD-induced genes were highly dependent on SWI/SNF enzymes. To understand the mechanism of activation, we performed chromatin immunoprecipitations analyzing the myogenin promoter. We found that H4 hyperacetylation preceded Brg1 binding in a MyoD-dependent manner but that MyoD binding occurred subsequent to H4 modification and Brg1 interaction. In the absence of functional SWI/SNF enzymes, muscle regulatory proteins did not bind to the myogenin promoter, thereby providing …

Phosphotyrosine Phosphatases Of The Att-20 Murine Corticotroph Cell Line, Kari A. Belin

Seton Hall University Dissertations and Theses (ETDs)

Somatostatin (somatotropin release inhibitory factor; SRIF) is a peptide-signaling molecule that activates a family of heterotrimeric guanine nucleotide binding protein (G­ protein) coupled receptors (sst.-sst-). SRIF receptors control essential intracellular signaling events and, by reducing cyclic nucleotide levels, ion concentrations and protein phosphorylation, ultimately controlling cell proliferation and secretion. In the current study, we investigated the intracellular phosphatase activity present in the AtT-20 cell, as well as whether these enzymes were under direct SRIF receptor control. AtT-20 cells retain many of the properties of anterior pituitary corticotrophs, yet are an established cell line that expresses at least two SRIF receptor …

Developing And Optimizing Conditions For Single Cell Genetic Analysis, Susan Adele Gitlin

Theses and Dissertations in Biomedical Sciences

Preimplantation Genetic Diagnosis (PGD) allows for couples to obtain genetic information at the embryo stage, therefore preventing lethal genetic diseases in their offspring. A recent multi-center study determined a 17% amplification failure rate overall and a 3.4% misdiagnosis rate (ESHRE PGD consortium steering committee, 2002). Experiments presented here were conducted to decrease those rates by optimizing single cell sensitivity and specificity of PGD techniques. Primer extension preamplification (PEP) was used after initial amplification failure, followed by gene specific PCR. Reamplification experiments yielded 54% amplification rates using blastomeres that previously failed amplification. In the clinical trial, four of six blastomeres were …

The Antitumor Agent, Arglabin-Dma, Preferentially Induces Apoptosis In Human Colon Tumor Cells, Sung Wook Kwon

Theses and Dissertations in Biomedical Sciences

Arglabin-DMA, an analog of farnesyl pyrophosphate (FPP), reportedly inhibits farnesyltransferase (FTase) directly by competitively blocking the binding of Ras protein and its posttranslational modification, as suggested in previous studies. But, the mechanisms by which Arglabin-DMA inhibits tumor growth in vivo and in vitro are still relatively poorly characterized. To determine the mechanism by which this drug inhibits tumor growth, the effects of Arglabin-DMA in two human colon tumor cell lines (mutant K-ras HCT 116 and wild-type ras HT-29) were explored on cell proliferation, apoptosis, and cell cycle kinetics in vitro. In cell viability studies, we showed that Arglabin-DMA …

The Glucose And Insulin Responsiveness Of The Rat Glucose-6-Phosphate Dehydrogenase Promoter, Daryl Arkwright-Keeler

Dissertations

The regulation of expression of some enzymes involved in glucose homeostasis and fat metabolism requires both insulin and glucose to elicit an effect, while the regulation of others requires only one. Glucose-6-phosphate dehydrogenase (G6PDH), an important enzyme involved in glucose homeostasis, has been shown to be transcriptionally regulated by carbohydrate feeding in rat liver, a diet regime that increases the levels of both glucose and insulin. Our lab had previously shown that insulin induces expression of G6PDH, thus we wanted to determine if glucose also induced G6PDH expression and if so, are the glucose and insulin responses mediated through identical …

Changes In Glial Cell Line Derived Neurotrophic Factor And Nerve Growth Factor Expression With Development, Age, Exercise And Hypertension, Bertha C. Rebimbas-Cohen

Dissertations

Neurotrophic factors are important for neuronal growth, survival, and maintenance of cell phenotype. Glial cell line-derived neurotrophic factor (GDNF) affects sensory, autonomic and somatic motor neurons and nerve growth factor (NGF) affects sensory and sympathetic neurons. NGF and GDNF are produced by cardiac muscle and have potent effects on sensory and autonomic neuronal innervation of blood vessels. Neural innervation plays a key role in blood vessel function. Since neural innervation of blood vessels may be regulated by growth factors, we wanted to determine what changes would occur to NGF and GDNF levels with maturity, exercise and hypertension.

Changes in GDNF …

Morphological And Molecular Defects In Zebrafish Embryos (Danio Rerio) After Chromated Copper Arsenate Exposure, Kerry Jean Lee

Biological Sciences Theses & Dissertations

This investigation identified the morphological defects caused by different concentrations of chromium, copper, and arsenic (CCA) on the developing zebrafish embryo; in addition to defects caused by the three combined components (complete CCA). A change in the DNA of the developing embryos in response to the three components of CCA and complete CCA was also determined. Early Dania rerio embryos were cultured for five days with various concentrations of CCA components and complete CCA. Morphological defects were assessed with light microscopy and DNA fragmentation was determined by agarose gel electrophoresis. Embryonic exposure of D. rerio to sub lethal concentrations of …

5-Ht1b Receptor-Mediated Presynaptic Inhibition Of Gaba Release In The Suprachiasmatic Nucleus, Jayne R. Bramley, Patricia J. Sollars, Gary E. Pickard, F. Edward Dudek

School of Veterinary and Biomedical Sciences: Faculty Publications

The suprachiasmatic nucleus (SCN) receives a dense serotonergic innervation that modulates photic input to the SCN via serotonin 1B (5-HT_1B) presynaptic receptors on retinal glutamatergic terminals. However, the majority of 5-HT_1B binding sites in the SCN are located on nonretinal terminals and most axonal terminals in the SCN are GABAergic. We therefore tested the hypothesis that 5-HT_1B receptors might also be located on SCN GABAergic terminals by examining the effects of the highly selective 5-HT_1B receptor agonist CP-93,129 on SCN miniature inhibitory postsynaptic currents (mIPSCs). Whole cell patch-clamp recordings of mIPSCs were obtained from rat …