Biochemistry, Biophysics, and Structural Biology Commons^™

Spontaneous Idiopathic Arteritis Of The Testicular Artery In Raccoons (Procyon Lotor), A. N. Hamir, M. V. Palmer, H. Li, J. Stasko, D. G. Rogers

School of Veterinary and Biomedical Sciences: Faculty Publications

The testes and the spermatic cord of raccoons (Procyon lotor, kits to adult breeders; n = 48) were examined. Segmental arteritis confined to the extratesticular portions of the testicular artery was present in raccoons of all ages. The arterial changes were seen in laboratory-confined experimental and control animals as well as in wild-caught raccoons. The lesions consisted of proliferative endarteritis with presence of inflammatory cells within the intima, media, and the adventitial regions of most affected vessels. Some aspects of the proliferative arterial lesions were reminiscent of systemic necrotizing vasculitis (polyarteritis nodosa), an immunologically mediated condition of animals and humans. …

Protection Of Macrophages J774a.1 By Purine Nucleoside Analogues From Bacillus Anthracis Mediated Necrosis, Zadkiel R. Alvarez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Eight years after the lamentable anthrax attacks, major scientific effort continues to be done, in order to stop imminent acts of bioterrorism. Innovative ways of therapy against the anthrax disease are being investigated. B. anthracis, the etiological agent of the infection, has a dormant stage in its life cycle known as the endospore. When conditions become favorable spores germinate, transforming into vegetative bacteria. In inhalational anthrax, the most fatal manifestation of the disease, spores enter the organism through the respiratory track, and are phagocytosized by alveolar macrophages of the lungs. Spores are able to sense nutrient availability, activating their germination …

An Inositolphosphorylceramide Synthase Is Involved In Regulation Of Plant Programmed Cell Death Associated With Defense In Arabidopsis, Wenming Wang, Xiaohua Yang, Samantha Tangchiaburana, Roland Ndeh, Jennifer E. Markham, Yoseph Tsegaye, Teresa M. Dunn, Guo-Liang Wang, Maria Bellizzi, James F. Parsons, Danielle Morrissey, Janis E. Bravo, Daniel V. Lynch, Shunyuan Xiao

Department of Biochemistry: Faculty Publications

The Arabidopsis thaliana resistance gene RPW8 triggers the hypersensitive response (HR) to restrict powdery mildew infection via the salicylic acid–dependent signaling pathway. To further understand how RPW8 signaling is regulated, we have conducted a genetic screen to identify mutations enhancing RPW8-mediated HR-like cell death (designated erh). Here, we report the isolation and characterization of the Arabidopsis erh1 mutant, in which the At2g37940 locus is knocked out by a T-DNA insertion. Loss of function of ERH1 results in salicylic acid accumulation, enhanced transcription of RPW8 and RPW8-dependent spontaneous HR-like cell death in leaf tissues, and reduction in plant stature. …

Intraretinal Signaling By Ganglion Cell Photoreceptors To Dopaminergic Amacrine Neurons, Dao-Qi Zhang, Kwoon Y. Wong, Patricia J. Sollars, David M. Berson, Gary E. Pickard, Douglas G. Mcmahon

School of Veterinary and Biomedical Sciences: Faculty Publications

Retinal dopaminergic amacrine neurons (DA neurons) play a central role in reconfiguring retinal function according to prevailing illumination conditions, yet the mechanisms by which light regulates their activity are poorly understood. We investigated the means by which sustained light responses are evoked in DA neurons. Sustained light responses were driven by cationic currents and persisted in vitro and in vivo in the presence of L-AP4, a blocker of retinal ON-bipolar cells. Several characteristics of these L-AP4-resistant light responses suggested that they were driven by melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs), including long latencies, marked poststimulus persistence, and a peak …

Regulation Of The Bioavailability Of Thioredoxin In The Lens By A Specific Thioredoxin-Binding Protein (Tbp-2), Namal P.M. Liyanage, M. Rohan Fernando, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

Thioredoxin (TRx) is known to control redox homeostasis in cells. In recent years, a specific TRx binding protein called thioredoxin binding protein-2 (TBP-2) was found in other cell types and it appeared to negatively regulate TRx bioavailability and thereby control TRx biological function. In view of the sensitivity of lens transparency to redox status, proper regulation of TRx bioavailability is of the utmost importance. This study was conducted to examine the presence and function of TBP-2 in human lens epithelial cells (HLE B3). We cloned human lens TBP-2 from a human cDNA library (GenBank accession number AY 594328) and showed …

Nanosecond Pulsed Electric Fields Induce A Mitochondria-Independent Apoptosis In B16f10 Melanoma Cells In Vitro, Wentia Elissa Ford

Theses and Dissertations in Biomedical Sciences

Nanosecond pulsed electric fields (nsPEFs) are ultra-short pulses that induce direct electric field and biological effects that initiate apoptosis. Here the application of ten 300ns pulses ranging in electric fields from 12kV/cm-60kV/cm was administered to determine the effects on B16F10 melanoma cells evaluated by in vitro studies. Initial application of nsPEFs demonstrated apoptosis induction in an electric field- and pulse number-dependent manner measured by caspase activation that correlated with decrease in cell viability 24hr post pulse. In addition caspase activity was shown to be independent of calcium mobilization though ions may play a part in other aspects of apoptosis. The …

Expression Analysis Of Plant Defense Responses During The Establishment Of Biotrophy And Role Of Abiotic Stress In The Infection Of Dyer’S Woad (Isatis Tinctoria) By Puccinia Thlaspeos, Elizabeth Thomas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The kinetics and amplitude of the salicylic acid-responsive pathogenesis-related (PR) genes and the cytochrome P450 gene ItCYP79B2 in the compatible interaction between Puccinia thlaspeos and dyer’s woad (Isatis tinctoria) during the first 72 hours of inoculation were examined. Immediately following penetration of the host by the rust pathogen, there was a modest up-regulation of PR genes but a significant down-regulation of ItCYP79B2 expression. During haustoria formation, a significant pathogen-mediated suppression of PR genes was observed with a corresponding up-regulation of ItCYP79B2. This potentially facilitates haustoria formation by P. thlaspeos. After haustoria formation, a more …

Cloning And Biochemical Characterization Of The Recq Helicase And Topoisomerase Iii In Schizosaccharomyces Pombe, Rebecca Wood

All Theses And Dissertations

RecQ and Topoisomerase III proteins are both essential for proper chromosomal maintenance in species ranging from bacteria to humans. Due to their highly conserved nature throughout evolution, understanding their basic biochemical properties as well as their interactions together is important for understanding human health, disease, and even to provide potential evolutionary insight. S. pombe has been chosen as a model organism because little research has been done on the biochemical analysis of its RecQ homolog, Rqhl. This study shows developments in the biochemical characterization of a truncation protein of Rqh1 including AFM (Atomic Force Microscopy) Imaging, DNA binding, and ATP …

Treg Depletion Inhibits Efficacy Of Cancer Immunotherapy: Implications For Clinical Trials., James Curtin, Marianela Candolfi, Tamer Fakhouri, Chunyan Liu, Anderson Alden, Matthew Edwards, Pedro Lowenstein, Maria Castro

Articles

BACKGROUND: Regulatory T lymphocytes (Treg) infiltrate human glioblastoma (GBM); are involved in tumor progression and correlate with tumor grade. Transient elimination of Tregs using CD25 depleting antibodies (PC61) has been found to mediate GBM regression in preclinical models of brain tumors. Clinical trials that combine Treg depletion with tumor vaccination are underway to determine whether transient Treg depletion can enhance anti-tumor immune responses and improve long term survival in cancer patients. FINDINGS: Using a syngeneic intracrabial glioblastoma (GBM) mouse model we show that systemic depletion of Tregs 15 days after tumor implantation using PC61 resulted in a decrease in Tregs …

Turning The Gene Tap Off; Implications Of Regulating Gene Expression For Cancer Therapeutics, James Curtin, Marianela Candolfi, Weidong Xiong, Pedro Lowenstein, Maria Castro

Articles

Cancer poses a tremendous therapeutic challenge worldwide, highlighting the critical need for developing novel therapeutics. A promising cancer treatment modality is gene therapy, which is a form of molecular medicine designed to introduce into target cells genetic material with therapeutic intent. Anticancer gene therapy strategies currently used in preclinical models, and in some cases in the clinic, include proapoptotic genes, oncolytic/replicative vectors, conditional cytotoxic approaches, inhibition of angiogenesis, inhibition of growth factor signaling, inactivation of oncogenes, inhibition of tumor invasion and stimulation of the immune system. The translation of these novel therapeutic modalities from the preclinical setting to the clinic …

Novel Role Of Antioxidant-1 (Atox1) As A Copper-Dependent Transcription Factor Involved In Cell Proliferation, S. Itoh, H. W. Kim, O. Nakagawa, K. Ozumi, Susan M. Lessner, H. Aoki, K. Akram, R. D. Mckinney, M. Ushio-Fukai, T. Fukai

Faculty Publications

Copper plays a fundamental role in regulating cell growth. Many types of human cancer tissues have higher copper levels than normal tissues. Copper can also induce gene expression. However, transcription factors that mediate copper-induced cell proliferation have not been identified in mammals. Here we show that antioxidant-1 (Atox1), previously appreciated as a copper chaperone, represents a novel copper-dependent transcription factor that mediates copper-induced cell proliferation. Stimulation of mouse embryonic fibroblasts (MEFs) with copper markedly increased cell proliferation, cyclin D1 expression, and entry into S phase, which were completely abolished in Atox1^-/- MEFs. Promoter analysis and EMSA revealed that copper …

Prostasin Is Expressed In Benign Prostatic Hyperplasia And Regulates Cell Proliferation And Invasion Via Inos, Icam-1, And Cycli, Meghan Hatfield

Electronic Theses and Dissertations

Prostasin is expressed in normal prostate epithelial cells but down-regulated in prostate cancers, while prostasin re-expression in invasive prostate cancer cells reduced invasion. We examined prostasin expression and function in benign prostatic hyperplasia (BPH). We evaluated prostasin expression in 12 BPH specimens by immunohistochemistry, and evaluated the impact of prostasin silencing by siRNA on the expression of the inducible nitric oxide synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1), and cyclin D1, as well as on cell proliferation and invasion, using the BPH-1 human prostate epithelial cell line model. Prostasin expression was localized in the glands of BPH tissues by immunohistochemistry, in …

Role Of Transient Receptor Potential Canonical-6 (Trpc6) Channel In Metastasis Of Glioblastoma Multiforme, Rajarajeshwari Venkataraman

Electronic Theses and Dissertations

Glioblastoma multiforme (GBM) is one of the extremely fatal brain tumors. The main reason that makes it so lethal is its capability to invade and spread to other parts of CNS producing secondary tumors. Among other factors hypoxia, reduced oxygen availability, is linked to higher metastatic potential of cancers. Hypoxia causes numerous changes in genome and proteome of the cell. These changes help a normal cell to adapt to nutritional deficiency, but the same changes can increase the malignancy and metastasis in tumor cells. Extensive research by a number of curious scientists reveal that various pathways involving numerous proteins cross-talk …

Bmp Signaling Goes Posttranscriptional In A Microrna Sort Of Way, Catherine A. Reinke, Richard W. Carthew

Faculty Publications

Aberrant microRNA (miRNA) expression correlates with human diseases such as cardiac disorders and cancer. Treatment of such disorders using miRNA-targeted therapeutics requires a thorough understanding of miRNA regulation in vivo. A recent paper in Nature by Davis et al. expands our understanding of miRNA biogenesis and maturation, elucidating a mechanism by which extracellular signaling directs cell differentiation via posttranscriptional regulation of miRNA expression.

Identification Of Lactic Acid Bacteria In Michigan Cherry Wines, Emily Henk, Margaret Dietrich, Terri Weese

Student Summer Scholars Manuscripts

Many factors contribute to the final flavor of wine. One factor is malolactic fermentation, during which lactic acid bacteria (LAB) transform the harsh tasting malic acid into a more drinkable lactic acid in grape wine. The role of LAB in the production of cherry wine is completely unknown. The goal of this study is to identify the species of LAB in cherry wine and compare them to those found in grape wines. Bacteria from cherry wine were grown on general media plates and plates fortified with malic acid, which may provide optimal growing conditions for the LAB. To identify the …

Maldi Mass Spectrometry Imaging For The Discovery Of Prostate Carcinoma Biomarkers, Lisa Harris Cazares

Theses and Dissertations in Biomedical Sciences

The elucidation of new biological markers of prostate cancer (PCa) should aid in the detection, and prognosis of this disease. Diagnostic decision making by pathologists in prostate cancer is highly dependent on tissue morphology. The ability to localize disease-specific molecular changes in tissue would help improve this critical pathology decision making process. Direct profiling of proteins in tissue sections using MALDI imaging mass spectrometry (MALDI-IMS) has the power to link molecular detail to morphological and pathological changes, enhancing the ability to identify candidates for new specific biomarkers. However, critical questions remain regarding the integration of this technique with clinical decision …

Subcellular Localization Of Human T-Cell Leukemia Virus Type 1 Tax Oncoprotein, Kimberly Anne Fryrear

Theses and Dissertations in Biomedical Sciences

Human T-cell Leukemia Virus Type 1 (HTLV-1) is a transforming retrovirus that gives rise to Adult T-cell Leukemia (ATL) and a variety of other subneoplastic conditions such as HTLV-Associated Myelopathy/Tropical Spastic Paraperesis (HAM/TSP). In ATL, the transformation and immortalization of T-lymphocytes has been attributed to the expression and activity of a single HTLV-1 viral protein, namely the trans-activating protein Tax. Although the exact mechanism of Tax-mediated transformation is uncertain, current studies support a model in which Tax induces genomic instability in the host cell through interference with DNA repair mechanisms, dysregulation of cell cycle progression, transcriptional activation of cellular …

Gene Therapy Using Tet-Repressor System To Modulate Prostate Tumor Microenvironment, Nazita Yousefieh

Theses and Dissertations in Biomedical Sciences

Prostate cancer is the most commonly diagnosed malignancy in men in the United States and is projected to be the third most frequent cause of male cancer-related deaths in 2007 after lung and skin cancers. The initial treatment for prostate cancer at early stages is prostatectomy or radiation, which usually is curative. However, approximately 20% of patients are not cured by such treatments and their cancer recurs, sometimes with long latencies. In other patients prostate cancer is diagnosed only after the cancer has metastasized and there are no effective therapies at this stage. Therefore immunotherapy seems to be a promising …

Light-Evoked Calcium Responses Of Isolated Melanopsin- Expressing Retinal Ganglion Cells, Andrew T. E. Hartwick, Jayne R. Bramley, Jianing Yu, Kelly T. Stevens, Charles N. Allen, William H. Baldridge, Patricia J. Sollars, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

A small number (<2%) of mammalian retinal ganglion cells express the photopigment melanopsin and are intrinsically photosensitive (ipRGCs). Light depolarizes ipRGCs and increases intracellular calcium levels ( [Ca²⁺]_i ) but the signaling cascades underlying these responses have yet to be elucidated. To facilitate physiological studies on these rare photoreceptors, highly enriched ipRGC cultures from neonatal rats were generated using anti-melanopsin-mediated plate adhesion (immunopanning). This novel approach enabled experiments on isolated ipRGCs, eliminating the potential confounding influence of rod/cone-driven input. Light induced a rise in [Ca²⁺]_i (monitored using fura-2 imaging) in the immunopanned ipRGCs and the source of this Ca²⁺ signal was investigated. The Ca²⁺ responses were inhibited by 2-aminoethoxydiphenyl borate, SKF-96365 (1–2-(4-methoxyphenyl)-2-[3-(4-methoxyphenyl)propoxy]ethyl-1H-imidazole), flufenamic acid, …

A Conserved Cam- And Radial Spoke–Associated Complex Mediates Regulation Of Flagellar Dynein Activity, Erin E. Dymek, Elizabeth F. Smith

Dartmouth Scholarship

For virtually all cilia and eukaryotic flagella, the second messengers calcium and cyclic adenosine monophosphate are implicated in modulating dynein- driven microtubule sliding to regulate beating. Calmodulin (CaM) localizes to the axoneme and is a key calcium sensor involved in regulating motility. Using immunoprecipitation and mass spectrometry, we identify members of a CaM-containing complex that are involved in regulating dynein activity. This complex includes flagellar-associated protein 91 (FAP91), which shares considerable sequence similarity to AAT-1, a protein originally identified in testis as an A-kinase anchor protein (AKAP)- binding protein. FAP91 directly interacts with radial spoke protein 3 (an AKAP), which …

Enhancement Of Efficacy Of Prrsv Vaccines By Altering The Glycosylation Pattern Of Viral Glycoproteins, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

PRRSV, the causative agent of PRRS is of major economic significance to the pork industry in the USA and around the world. Current commercial vaccine does not provide adequate protection against PRRSV outbreaks. Therefore, there is an urgent need for development of more efficacious vaccine to combat PRRS. Our previous studies have suggested that (i) induction of neutralizing antibody response is an important correlate of evaluating the efficacy of a vaccine; (ii) neutralizing antibodies can be enhanced by hypoglycosylation of the major surface glycoprotein (GP5). While it is known that GP5 plays a prominent role in neutralizing antibody induction, it …

Mutations Affecting A Putative Mutla Endonuclease Motif Impact Multiple Dna Mismatch Repair Functions, Naz Erdeniz, Megan Nguyen, Suzanne M. Deschênes, R. Michael Liskay

Biology Faculty Publications

Mutations in DNA mismatch repair (MMR) lead to increased mutation rates and higher recombination between similar, but not identical sequences, as well as resistance to certain DNA methylating agents. Recently, a component of human MMR machinery, MutLα, has been shown to display a latent endonuclease activity. The endonuclease active site appears to include a conserved motif, DQHA(X)₂E(X)₄E, within the COOH-terminus of human PMS2. Substitution of the glutamic acid residue (E705) abolished the endonuclease activity and mismatch-dependent excision in vitro. Previously, we showed that the PMS2-E705K mutation and the corresponding mutation in Saccharomyces cerevisiae were …

The Yeast Integral Membrane Protein Apq12 Potentially Links Membrane Dynamics To Assembly Of Nuclear Pore Complexes, John J. Scarcelli, Christin A. Hodge, Charles N. Cole

Dartmouth Scholarship

Although the structure and function of components of the nuclear pore complex (NPC) have been the focus of many studies, relatively little is known about NPC biogenesis. In this study, we report that Apq12 is required for efficient NPC biogenesis in Saccharomyces cerevisiae. Apq12 is an integral membrane protein of the nuclear envelope (NE) and endoplasmic reticulum. Cells lacking Apq12 are cold sensitive for growth, and a subset of their nucleoporins (Nups), those that are primarily components of the cytoplasmic fibrils of the NPC, mislocalize to the cytoplasm. APQ12 deletion also causes defects in NE morphology. In the absence of …

Low Molecular Weight Protein Tyrosine Phosphatase (Lmw-Ptp) And Its Possible Physiological Functions Of Redox Signaling In The Eye Lens, Kuiyi Xing, Ashraf Raza, Stefan Lofgren, M. Rohan Fernando, Ye-Shih Ho, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

Low molecular weight protein tyrosine phosphatase (LMW-PTP) was cloned from human lens epithelial B3 cells (HLE B3) and the recombinant enzyme was purified to homogeneity. The pure enzyme reacted positively with anti-LMW-PTP antibody, displayed tyrosine-specific phosphatase activity and was extremely sensitive to H2O2. The inactivated LMW-PTP could be regenerated by thioltransferase (TTase)/GSH system as demonstrated by both activity assay and by mass spectrometry (MS). The MS study also showed that an intramolecular disulfide bond was formed between C13 and C18 at the active site, and was reduced by the TTase/GSH system. The putative role of LMW-PTP in regulating platelet derived …

The Effects Of Aging And Activity On Glial Cell Line-Derived Neurotrophic Factor Expression In Skeletal Muscle, Nathan Peplinski

Dissertations

Glial cell line-derived neurotrophic factor (GDNF) is an extracellular signaling protein that is produced by skeletal muscle and is important for the motor neurons that control muscle movement. GDNF has been shown to keep neurons alive under conditions that they would otherwise not persist. In skeletal muscle, GDNF has been shown to be one of the most potent neurotrophic factors that influence motor neuron survival. While the role of GDNF has been well studied during early development, not much is known about what happens to GDNF expression in the adult and with advanced aging. Previous results from our lab have …

Water. New Waters And New Life, Juan Enriquez

New England Journal of Public Policy

An excerpt from an article about life sciences taken from the proceedings of the Education for Public Inquiry and International Citizenship (EPIIC) Symposium held at Tufts University in Massachusetts in February 2005 is presented.

Characterization Of Molecular Events Following Heavy Metal Cadmium Exposure: A Cellular Regulatory Symphony In Response To Early Cadmium Insult, Chin-Ju Jean Hsiao

Dissertations

Cadmium, a non-essential toxic heavy metal, has been classified as a human carcinogen and one of the most hazardous substances in our environment. Since it can circulate within the food chain, has a long biological half-life and can bio-accumulate, it has the potential to induce detrimental health effects linked to toxicity, cancer and chronic diseases.

In recent years progress has been made to dissect and understand the molecular mechanisms underlying the effects of cadmium exposure. However, few studies have focused on investigating potential protective and/or defense mechanisms naturally applied by cells upon initial exposure, prior to any damage or toxic …

Stoichiometric Controls Of Mercury Dilution By Growth, Roxanne Karimi, Celia Y. Chen, Paul C. Pickhardt, Nicholas S. Fisher, Carol L. Folt

Dartmouth Scholarship

Rapid growth could significantly reduce methylmercury (MeHg) concentrations in aquatic organisms by causing a greater than proportional gain in biomass relative to MeHg (somatic growth dilution). We hypothesized that rapid growth from the consumption of high-quality algae, defined by algal nutrient stoichiometry, reduces MeHg concentrations in zooplankton, a major source of MeHg for lake fish. Using a MeHg radiotracer, we measured changes in MeHg concentrations, growth and ingestion rates in juvenile Daphnia pulex fed either high (C:P = 139) or low-quality (C:P = 1317) algae (Ankistrodesmus falcatus) for 5 d. We estimated Daphnia steady-state MeHg concentrations, using a …

The Yeast Orthologue Of Grasp65 Forms A Complex With A Coiled-Coil Protein That Contributes To Er To Golgi Traffic, Rudy Behnia, Francis A. Barr, John J. Flanagan, Charles Barlowe, Sean Munro

Dartmouth Scholarship

The mammalian Golgi protein GRASP65 is required in assays that reconstitute cisternal stacking and vesicle tethering. Attached to membranes by an N-terminal myristoyl group, it recruits the coiled-coil protein GM130. The relevance of this system to budding yeasts has been unclear, as they lack an obvious orthologue of GM130, and their only GRASP65 relative (Grh1) lacks a myristoylation site and has even been suggested to act in a mitotic checkpoint. In this study, we show that Grh1 has an N-terminal amphipathic helix that is N-terminally acetylated and mediates association with the cis-Golgi. We find that Grh1 forms a complex with …

Mechanism Of Action And Regulation Of Membrane Serine Protease Prostasin In The Prostate And Prostate Cancer, Mengqian Chen

Electronic Theses and Dissertations

The glycosylphosphatidylinositol (GPI)-anchored serine protease prostasin (PRSS8) is expressed at the apical membrane surface of epithelial cells and acts as a suppressor of tumor invasion when re-expressed in highly invasive human prostate and breast cancer cell lines. To better understand the molecular mechanisms underlying the anti-invasion phenotype associated with prostasin re-expression in prostate cancer cells, we expressed wild-type human prostasin or a serine active-site mutant prostasin in the PC-3 human prostate carcinoma cells. Molecular changes were measured at the mRNA and the protein levels. The expression of several invasion-promoting molecules is regulated by prostasin re-expression, mediated by a protein-level down-regulation …