Cell and Developmental Biology Commons^™

Leptin Protects Dendritic Cells From Chemically-Induced Cell Death, Yadira Arellano^, Jeffrey Charles Sivils, Kristine Marie Garza*

COURI Symposium Abstracts, Spring 2011

Leptin is a pleiotropic adipokine that exerts its physiological effects by binding to its receptor, which is expressed in many immune cells including T cells, macrophages, and dendritic cells. Multidrug resistance-associated protein (MRP) is a transmembrane transporter commonly associated with cancer cells conferring resistance to chemotherapy. The purpose of this study is to determine if leptin supersedes the cytotoxic death signal in dendritic cells. We further hypothesize that the mechanism underlying leptin protection is a result of over expression of MRPs. To address this question, we examined the effect of leptin on monocytes treated with cytotoxic drugs in vitro.  Bone …

Role Of Wnt5a And Possible Pathway Of Action Through Ror2 In Proximodistal Outgrowth Of The Limb, Tiffanie M. Dahl

Theses and Dissertations

Despite over 60 years of study, the molecular pathways and mechanisms governing limb outgrowth and patterning remain poorly understood. Fgfs expressed in the AER are known to be necessary and sufficient for proximodistal limb outgrowth and have been proposed to have a chemoattractive role. Wnt5a is a secreted factor which is expressed in a gradient in the distal limb with the highest concentration next to the AER. The presence of the AER is necessary to establish this gradient. Expression of Wnt5a in a concentration dependant manner can be induced in the limb through the implantation of a bead soaked in …

Novel Strains Of Mice Deficient For The Vesicular Acetylcholine Transporter: Insights On Transcriptional Regulation And Control Of Locomotor Behavior, Christina Martins-Silva, Xavier De Jaeger, Monica S. Guzman, Ricardo D. F. Lima, Magda S. Santos, Christopher Kushmerick, Marcus V. Gomez, Marc G. Caron, Marco A. M. Prado, Vania F. Prado

Anatomy and Cell Biology Publications

Defining the contribution of acetylcholine to specific behaviors has been challenging, mainly because of the difficulty in generating suitable animal models of cholinergic dysfunction. We have recently shown that, by targeting the vesicular acetylcholine transporter (VAChT) gene, it is possible to generate genetically modified mice with cholinergic deficiency. Here we describe novel VAChT mutant lines. VAChT gene is embedded within the first intron of the choline acetyltransferase (ChAT) gene, which provides a unique arrangement and regulation for these two genes. We generated a VAChT allele that is flanked by loxP sequences and carries the resistance cassette placed in a ChAT …

Angiostatin Like Peptides In Milk: Potential Development For Dairy Products Capable Of Cancer Prevention, Erin Stefanutti

Master's Theses

For the past 40 years, antiangiogenic approaches have been of major interest in the development of methods to cure and prevent cancer. Angiogenesis, the development of blood vessels from pre-existing vascularization, is essential for cancer growth and spread of metastasis through the delivery of nutrients and oxygen essential to sustain the metabolic activity of these malignant cells. Blocking access to blood will cause cancerous cells to assume a dormant state creating inactive micro-tumors innocuous to the host. Angiostatin, the internal fragment of the fibrinolytic zymogen plasminogen, has shown great potential in reducing cancer size and number of metastatic colonies in …

Low Levels Of Hydrogen Peroxide Stimulate Corneal Epithelial Cell Adhesion, Migration, And Wound Healing, Qing Pan, Wen-Ya Qiu, Ya-Nan Huo, Yu-Feng Yao, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

PURPOSE. Intracellular reactive oxygen species have been reported to associate with growth factor and integrin signalings in promoting cell adhesion in many cell types. This study is to explore if exogenous H2O2 at low levels can be beneficial to cell adhesion, migration, and wound healing.

METHODS. Primary rabbit corneal epithelial cells treated with 0–70 M H2O2 were tested for viability by MTT assay, adhesion by centrifugation assay, focal contacts of vinculin and F-actin by immunofluorescence, activated Src(pY416), EGF receptor (pY845), vinculin(pY1065), FAK(pY397), and FAK(pY576) by immunoblotting. Cell migration was examined with 0–50 M H2O2 using the scratch wound technique. Corneal …

Limited Transplantation Of Antigen-Expressing Hematopoietic Stem Cells Induces Long-Lasting Cytotoxic T Cell Responses, Warren L. Denning, Jun Xu, Siqi Guo, Christopher A. Klug, Zdenek Hel

Bioelectrics Publications

Harnessing the ability of cytotoxic T lymphocytes (CTLs) to recognize and eradicate tumor or pathogen-infected cells is a critical goal of modern immune-based therapies. Although multiple immunization strategies efficiently induce high levels of antigen-specific CTLs, the initial increase is typically followed by a rapid contraction phase resulting in a sharp decline in the frequency of functional CTLs. We describe a novel approach to immunotherapy based on a transplantation of low numbers of antigen-expressing hematopoietic stem cells (HSCs) following nonmyeloablative or partially myeloablative conditioning. Continuous antigen presentation by a limited number of differentiated transgenic hematopoietic cells results in an induction and …

Electroporation-Induced Electrosensitization, Olga N. Pakhomova, Betsy W. Gregory, Vera A. Khorokhorina, Anglela M. Bowman, Shu Xiao, Andrei G. Pakhomov

Bioelectrics Publications

BACKGROUND: Electroporation is a method of disrupting the integrity of cell membrane by electric pulses (EPs). Electrical modeling is widely employed to explain and study electroporation, but even most advanced models show limited predictive power. No studies have accounted for the biological consequences of electroporation as a factor that alters the cell's susceptibility to forthcoming EPs.

METHODOLOGY/PRINCIPAL FINDINGS: We focused first on the role of EP rate for membrane permeabilization and lethal effects in mammalian cells. The rate was varied from 0.001 to 2,000 Hz while keeping other parameters constant (2 to 3,750 pulses of 60-ns to 9-micros duration, 1.8 …

Follicle-Stimulating Hormone Promotes Rank Expression On Human Monocytes, Joseph G. Cannon, Barbara Kraj, Gloria Sloan

School of Medical Diagnostics & Translational Sciences Publications

Elevated serum concentrations of follicle-stimulating hormone (FSH) are associated with diminished bone density in women, beginning years before menopause and the decline in estradiol. We hypothesized that FSH promotes development of myeloid cells toward the bone-resorbing osteoclast phenotype. This was tested by isolating peripheral blood mononuclear cells from nine healthy adults, incubating them in the presence of FSH at three different concentrations spanning the physiological range, and then measuring the expression of receptor activator for NF-κB (RANK, a surface marker for osteoclasts) on CD14+ cells by flow cytometry. In the absence of FSH, 3.3±0.5% of the cells expressed high levels …

Dynamic Glucoregulation And Mammalian-Like Responses To Metabolic And Developmental Disruption In Zebrafish, Agata Jurczyk, Nicole M. Roy, Rabia Bajwa, Philipp Gut, Kathryn Lipson, Chaoxing Yang, Laurence Covassin, Waldemar J. Racki, Aldo A. Rossini, Nancy Phillips, Didier Y. R. Stainier, Dale L. Greiner, Michael A. Brehm, Rita Bortell, Philip Diiorio

Biology Faculty Publications

Zebrafish embryos are emerging as models of glucose metabolism. However, patterns of endogenous glucose levels, and the role of the islet in glucoregulation, are unknown. We measured absolute glucose levels in zebrafish and mouse embryos, and demonstrate similar, dynamic glucose fluctuations in both species. Further, we show that chemical and genetic perturbations elicit mammalian-like glycemic responses in zebrafish embryos. We show that glucose is undetectable in early zebrafish and mouse embryos, but increases in parallel with pancreatic islet formation in both species. In zebrafish, increasing glucose is associated with activation of gluconeogenic phosphoenolpyruvate carboxykinase1 (pck1) transcription. Non-hepatic Pck1 protein is …

Performance Screening Of Chemostat Adapted Recombinant Zymomonas Mobilis Strains, Deirdre M. Beard, Nancy Dowe

STAR Program Research Presentations

Corn stover biomass can be pretreaed and hydrolyzed into soluble sugars to be fermented by microorganisms to ethanol. NREL has developed a recombinant bacteria Zymomonas mobilis 8b that metabolizes both five and six carbon sugars. During pretreatment, toxic inhibitors such as furfural and acetate are produced. NREL has made an attempt to adapt two sub-strains of Z. mobilis 8b to acetate and furfural by using a chemostat method. During the chemostat process, cultures were frozen back in glycerol and saved. In this study, those frozen cultures were revived and analyzed for performance in environments with varying concentrations of furfural and …

Mechanisms Of Yttrium Oxide Toxicity In Hek293 Cells, Sravanthi Bodapati

Theses, Dissertations and Capstones

As a non-metal oxide, yttrium oxide (Y2O3) nanoparticles have numerous applications in chemical synthesis, mechanical polishing and as additives to drugs, cosmetics, varnishes and food. Recent data have suggested that these particles are capable of inducing oxidative stress and cytotoxicity in human endothelial cell lines. To examine the potential mechanisms of yttrium oxide toxicity, human embryonic kidney (HEK293) cells were exposed to 1, 5, 10, 50 and 100 μM of Y2O3 nanoparticles for 12, 24, 36 or 48 hr. We hypothesized that exposure of HEK293 kidney cells to Y2O3 nanoparticles would be associated with increased evidence of intracellular oxidative stress …

Expression Of Genes Involved In A Radiation-Induced Bystander Effect, Hayley Furlong

Conference Papers

The radiation induced bystander effect is relevant to carcinogenesis, it may have significant implications for risk estimation for radiation exposure. Currently the mechanisms and cellular events are the subject of intense investigation, because little is known. It is thought that the radiation induced bystander response is due to a bystander factor secreted in the medium post irradiation. However the biological nature of this factor is currently unknown, but it is thought to be a protein of some sort that may be involved in the apoptosis cascade. Materials and Methods: HaCaT epithelial cells were used in this study and exposed to …

Do Longer Delays Matter? The Effect Of Prolonging Delay In Ctl Activation, Angela Gallegos, Ami E. Radunskaya

Pomona Faculty Publications and Research

The activation of a specific immune response takes place in the lymphoid organs such as the spleen. We present here a simplified model of the proliferation of specific immune cells in the form of a single delay equation. We show that the system can undergo switches in stability as the delay is increased, and we interpret these results in the context of sustaining an effective immune response to a dendritic cell vaccine.

The Role Of The Sparc Acidic Domain And Egf-Like Module In Glioma Migration, Invasion, And Signaling, Heather M. Mcclung

Wayne State University Dissertations

THE ROLE OF THE SPARC ACIDIC DOMAIN AND EGF-LIKE MODULE IN GLIOMA MIGRATION, INVASION, AND SIGNALING

HEATHER M. MCCLUNG

Advisor: Sandra A. Rempel, Ph.D.

Major: Pharmacology

Degree: Doctor of Philosophy

We have previously shown that Secreted Protein Acidic and Rich in Cysteine (SPARC) is upregulated in all astrocytoma grades and increases tumor cell migration and invasion. It is thought that different domains within the protein may regulate SPARC functions, suggesting domain-specific targeting to inhibit invasion. To enhance our understanding of SPARC-mediated invasion, we first confirm, at the protein level, our previous cDNA array results, that SPARC increases expression of the …

Palmitoylation And The Yeast Casein Kinase Yck2, Irene Papanayotou

Wayne State University Dissertations

Palmitoylation is a post-translational lipid modification that allows proteins to interact with membranes. In the yeast Saccharomyces cerevisiae, the casein kinase Yck2 is palmitoylated twice at its two C-terminal palmitoyl-accepting cysteine residues, by the palmitoyl-transferring enzyme Akr1. Once palmitoylated, Yck2 traffics through the well characterized secretory pathway to the plasma membrane where it participates in many cellular functions, including bud morphogenesis, cytokinesis, nutrient sensing, and receptor internalization. While the hydrophilic Yck2 is presumably synthesized on cytosolic ribosomes, it gains access to the membrane system by interaction with the six transmembrane-spanning Golgi-localized Akr1. Since palmitoylation occurs at membranes and the palmitoyl-transferases …

Stress-Induced Proteolysis Of Fkbp10: Mutational Analysis And Functional Implications, Lindsey A. Murphy

Featured Research

Cellular signaling is a complex system of communication that regulates cell function through a variety of molecular messengers. When cell survival is threatened by changes in environment or by malfunction of internal regulatory pathways, signals are initiated to restore homeostasis. Deficient protein processing within the endoplasmic reticulum (ER) causes an accumulation of misfolded proteins and stress signaling. The resulting stress signaling includes both adaptive signals (unfolded protein response) and in cases of severe ER stress apoptotic signals induced via the mitochondria. FKBP10 is a key ER luminal peptidy-prolyl isomerase (rotamase) that mediates protein folding. The production of chaperone proteins and …

The Process Of Autophagy In An In Vitro Model Of Myocardial Ischemia-Reperfusion Injury, Kadija Abounit

Wayne State University Dissertations

Autophagy has been implicated in the pathogenesis of myocardial ischemia-reperfusion (I/R) injury; however, it is not clear whether autophagy is beneficial or detrimental to cell survival. We hypothesized that autophagy is beneficial to cardiomyocytes during I/R and that the paucity of ATP may limit its occurrence. To test this hypothesis, we developed a model of ischemia (hypoxia) involving exposure of HL-1 murine atrial cardiomyocytes to two concentrations of oxygen (0.5% and 2.0%) and 2-deoxyglucose.

Hypoxia, irrespective of the oxygen concentration, caused a dramatic drop in cellular ATP and an increase in the phosphorylation of AMPK (an indication of energy starvation),. …

Analysis Of Biological Features Associated With Meiotic Recombination Hot And Cold Spots In Saccharomyces Cerevisiae, Loren Hansen, Nak-Kyeong Kim, Leonardo Mariño-Ramírez, David Landsman

Mathematics & Statistics Faculty Publications

Meiotic recombination is not distributed uniformly throughout the genome. There are regions of high and low recombination rates called hot and cold spots, respectively. The recombination rate parallels the frequency of DNA double-strand breaks (DSBs) that initiate meiotic recombination. The aim is to identify biological features associated with DSB frequency. We constructed vectors representing various chromatin and sequence-based features for 1179 DSB hot spots and 1028 DSB cold spots. Using a feature selection approach, we have identified five features that distinguish hot from cold spots in Saccharomyces cerevisiae with high accuracy, namely the histone marks H3K4me3, H3K14ac, H3K36me3, and H3K79me3; …

Disorder Predictors Also Predict Backbone Dynamics For A Family Of Disordered Proteins, Gary W. Daughdrill, Wade M. Borcherds, Hongwei Wu

Molecular Biosciences Faculty Publications

Several algorithms have been developed that use amino acid sequences to predict whether or not a protein or a region of a protein is disordered. These algorithms make accurate predictions for disordered regions that are 30 amino acids or longer, but it is unclear whether the predictions can be directly related to the backbone dynamics of individual amino acid residues. The nuclear Overhauser effect between the amide nitrogen and hydrogen (NHNOE) provides an unambiguous measure of backbone dynamics at single residue resolution and is an excellent tool for characterizing the dynamic behavior of disordered proteins. In this report, we show …

Critical Role Of Leucine-Valine Change In Distinct Low Ph Requirements For Membrane Fusion Between Two Related Retrovirus Envelopes, Marceline Côté, Yi-Min Zheng, Kun Li, Shi-Hua Xiang, Lorraine M. Albritton, Shan-Lu Liu

Nebraska Center for Virology: Faculty Publications

Many viruses use a pH-dependent pathway for fusion with host cell membrane, the mechanism of which is still poorly understood. Here we report that a subtle leucine (Leu)-valine (Val) change at position 501 in the envelope glycoproteins (Envs) of two related retroviruses, jaagsiekte sheep retro-virus (JSRV) and enzootic nasal tumor virus (ENTV), is responsible for their distinct low pH requirements for membrane fusion and infection. The Leu and Val residues are predicted to reside within the C-terminal heptad repeat (HR2) region of JSRV and ENTV Envs, particularly proximal to the hairpin turn of the putative six-helix bundle (6HB). Substitution of …