Life Sciences Commons^™

Investigating The Impact Of Oxidative Stress On Tetrahymena Thermophila Sirtuin,Thd 18, Emmanuel Dubuisson

Publications and Research

Sirtuins are a family of enzymes that fulfill various important biological functions. Investigators have looked for the implication of Sirtuin genes in cell signaling mechanisms, in the formation and silencing of heterochromatin, in the regulation of ion channels, and in the modulation of the cellular redox reactions[2]. Different model organisms have been previously used to conduct these studies; among them, there are yeasts, nematodes, and fruit flies. Each one has made some valuable contribution into the vast body of knowledge related to this field.

However, gaps in the understanding of Sirtuins functions still remain to be filled. In this optic, …

Pyronaridine Exerts Potent Cytotoxicity On Human Breast And Hematological Cancer Cells Through Induction Of Apoptosis, Paulina J. Villanueva, Alberto Martinez, Sarah T. Baca, Rebecca E. Dejesus, Manuel Larragoity, Lisett Contreras, Denisse A. Gutierrez, Armando Varela-Ramirez, Renato J. Aguilera

Publications and Research

The potent antimalarial drug pyronaridine (PND) was tested for its potential as an anticancer drug. After exposing cancerous (17) and non-cancerous (2) cells to PND for 72 hr, PND was found to exhibit consistent and potent cytotoxic activity at low micromolar (μM) concentrations that ranged from 1.6 μM to 9.4 μM. Moreover, PND exerted a significant selective cytotoxicity index (SCI) on five out of seven breast cancer cell lines tested, with favorable values of 2.5 to 4.4, as compared with the non-cancerous breast MCF-10A cell line. By using the same comparison, PND exhibited a significant SCI on three out of …

Unravelling The Structure Of Glycosyl Cations Via Cold-Ion Infrared Spectroscopy, Eike Mucha, Mateusz Marianski, Fei-Fei Xu, Daniel A. Thomas, Gerard Meijer, Gert Von Helden, Peter H. Seeberger, Kevin Pagel

Publications and Research

Glycosyl cations are the key intermediates during the glycosylation reaction that covalently links building blocks during the synthetic assembly of carbohydrates. The exact structure of these ions remained elusive due to their transient and short-lived nature. Structural insights into the intermediate would improve our understanding of the reaction mechanism of glycosidic bond formation. Here, we report an in-depth structural analysis of glycosyl cations using a combination of cold-ion infrared spectroscopy and first-principles theory. Participating C2 protective groups form indeed a covalent bond with the anomeric carbon that leads to C1-bridged acetoxonium-type structures. The resulting bicyclic structure strongly distorts the ring, …

The Role Of Proton Transport In Gating Current In A Voltage Gated Ion Channel, As Shown By Quantum Calculations, Alisher M. Kariev, Michael E. Green

Publications and Research

Over two-thirds of a century ago, Hodgkin and Huxley proposed the existence of voltage gated ion channels (VGIC) to carry Na⁺ and K⁺ ions across the cell membrane to create the nerve impulse, in response to depolarization of the membrane. The channels have multiple physiological roles, and play a central role in a wide variety of diseases when they malfunction. The first channel structure was found by MacKinnon and coworkers in 1998. Subsequently the structure of a number of VGIC was determined in the open (ion conducting) state. This type of channel consists of four voltage sensing domains …

Phospholipase D-Dependent Mtorc1 Activation By Glutamine, Elyssa Bernfeld

Dissertations, Theses, and Capstone Projects

Glutamine, the conditionally essential amino acid and most abundant amino acid in human sera, is a key nutrient required for sustaining cell proliferation. Glutamine is essential for nucleotide, protein, and lipid synthesis, all of which are essential for cell proliferation. The mammalian target of rapamycin complex 1 (mTORC1) is a highly conserved protein complex that acts as a sensor of nutrients, relaying signals for the shift from catabolic to anabolic metabolism. While glutamine plays an important role in activating mTORC1, the mechanism is not completely clear. Here we describe a Rag-independent mechanism of mTORC1 activation by glutamine that is dependent …

Strategies Involving The Food-Derived Agent Curcumin To Eliminate Brain Cancer, Sumit Mukherjee

Dissertations, Theses, and Capstone Projects

Glioblastoma (GBM) is one of the most deadly forms of cancer with a mean 5-year survival rate of ≤5%. We have used the non-invasive strategy of long-term intranasal (IN) delivery of a glioblastoma-directed adduct of curcumin (CC), CC-CD68Ab, into the brain of murine GBM cell line GL261-implanted mice to study the therapeutic effect of CC on GBM remission. The treatment caused GBM tumor remission in 50% of GL261-implanted GBM mice. A similar rescue rate (60%) was also achieved through long-term intraperitoneal (i.p) infusion of a highly bioavailable phosphotidylcholine (PC)-encapsulated formulation of CC, Curcumin Phytosome Meriva (CCP), into the GL261-implanted GBM …

Renal Risk Variants Of Apolipoprotein L-1 Form Channels At The Plasma Membrane That Lead To A Cytotoxic Influx Of Calcium, Joseph A. Giovinazzo

Dissertations, Theses, and Capstone Projects

Apolipoprotein L-1 (APOL1) is a secreted protein that provides protection against several protozoan parasites due to its channel forming properties. Recently evolved variants, G1 and G2, increase kidney disease risk when present in two copies. In mammalian cells, overexpression of G1 and G2, but not wild-type G0, leads to swelling and eventual lysis. However, the mechanism of cell death remains elusive with multiple pathways being invoked, such as autophagic cell death mediated by a BH3 domain in APOL1, which we evaluated in this study. We hypothesized that the common trigger for these pathways is the APOL1 cation channel, which is …

Integration Of Bmp And Insulin/Igf-1 Signaling Regulates Multiple Homeostatic Functions In Caenorhabditis Elegans, James F. Clark

Dissertations, Theses, and Capstone Projects

The maintenance of homeostatic functions is key to the survival and well-being of an organism. Regulation of homeostasis relies on varied inputs, both intrinsic and extrinsic, to potentiate a web of interconnected signaling relays. Insulin/IGF-1 signaling (IIS) is a well-known regulator of glucose and lipid metabolism, as well as having far reaching effects in other homeostatic mechanisms. On the other hand, bone morphogenetic protein (BMP), a member of the transforming growth factor beta signaling superfamily, is known for its role in differentiation and development, with only recent studies highlighting potential roles in metabolic homeostasis. Here we elucidate new functions for …

Mechanisms Adopted By Dengue-2 Viruses To Induce Autophagy In Mammalian Cells, Sounak Ghosh Roy

Dissertations, Theses, and Capstone Projects

Dengue, the most rapidly spreading flavivirus, threatens to affect almost half of the human global population. We previously showed that dengue-2 protects canine kidney cells (MDCK) from cytotoxic chemicals. We showed, independently, that cell protection, as well as viral replication and maturation, are positively regulated by PI3K-dependent autophagy. However, we had not identified the specific pathway that induces autophagy in infected cells. The current study explores the role of a specific branch of the endoplasmic reticulum (ER) stress-mediated Unfolded Protein Response (UPR), the PERK/eIF2α/ATF4 pathway in the induction of autophagy by …

Molecular Interactions Between Pvt1 Transcripts And C-Myc, Onayemi Titilayo Onagoruwa

Theses and Dissertations

This study focused on the molecular relationships between PVT1 exons 4A, 4B, 9 and c-Myc in prostate cancer. Data showed significant regulatory interactions between these exons and c-Myc which is strongest between PVT1 exon 9 and c-Myc. This will likely have implications for PCa where PVT1 and c-Myc are dysregulated.

Lim Protein Ajuba Associates With The Rpa Complex Through Direct Cell Cycle-Dependent Interaction With The Rpa70 Subunit, Sandy Fowler, Pascal Maguin, Sampada Kalan, Diego Loayza

Publications and Research

DNA damage response pathways are essential for genome stability and cell survival. Specifically, the ATR kinase is activated by DNA replication stress. An early event in this activation is the recruitment and phosphorylation of RPA, a single stranded DNA binding complex composed of three subunits, RPA70, RPA32 and RPA14. We have previously shown that the LIM protein Ajuba associates with RPA, and that depletion of Ajuba leads to potent activation of ATR. In this study, we provide evidence that the Ajuba-RPA interaction occurs through direct protein contact with RPA70, and that their association is cell cycle-regulated and is reduced upon …

Δ-9-Thc Effect On The Dopamine Transporter, Brooke E. Nielsen

Student Theses

Understanding the mechanism behind drugs of abuse is one of the key elements to understanding why addiction is so prevalent in society. The goal of this research was to determine the effect that a popular cannabinoid, Δ -9-tetrahydrocannabinol has on the regulation of dopamine neurotransmitter in the synapses. It was hypothesized that the addictive high users experience from using Δ-9-THC had a direct effect on lowering the dopamine transporter protein on cell surface causing a buildup of dopamine in the synapse. The results of the study show that the higher concentration of Δ-9-THC that the cells were exposed to caused …

Perinatal Pb2+ Exposure Alters The Expression Of Genes Related To The Neurodevelopmental Gaba-Shift In Postnatal Rats, Lorenz Simon Neuwirth, Greg R. Phillips, Abdeslem El Idrissi

Publications and Research

Background: Lead (Pb2+) is an environmental neurotoxicant that disrupts neurodevelopment, communication, and organization through competition with Ca2+ signaling. How perinatal Pb2+ exposure affects Ca2+-related gene regulation remains unclear. However, Ca2+ activates the L-Type voltage sensitive calcium channel β-3 subunit (Ca-β3), which autoregulates neuronal excitability and plays a role in the GABA-shift from excitatory-toinhibitory neurotransmission.

Method: A total of eight females (n = 4 Control and n = 4 Perinatal) and four males (n = 2 Control and n = 2 Perinatal) rats were used as breeders to serve as Dams and Sires. The Dam’s litters each ranged from N = …

Eukaryotic Translation Initiation Factor 4a Down-Regulation Mediates Interleukin-24-Induced Apoptosis Through Inhibition Of Translation, Xuelin Zhong, Leah Persaud, Hilal Muharam, Ashleigh Francis, Dibash Das, Bertal Huseyin Atkas, Moire Sauane

Publications and Research

Dysregulated activity of helicase eIF4A drives transformation to and maintenance of cancer cell phenotype by reprogramming cellular translation. Interleukin 24 (IL-24) is a tumor-suppressing protein, which has the ability to inhibit angiogenesis, sensitize cancer cells to chemotherapy, and induce cancer cell-specific apoptosis. In this study, we found that eIF4A is inhibited by IL-24. Consequently, selective reduction of translation was observed for mRNAs harboring strong secondary structures in their 50 -untranslated regions (50UTRs). These mRNAs encode proteins, which function in cell survival and proliferation. Consistently, overexpression of eIF4A conferred cancer cells with resistance to IL-24-induced cell death. It has been established …

Antioxidants And Cancer: Theories, Techniques, And Trials In Preventing Cancer, Gloria M. Calaf, Francisco Aguayo, Consolato M. Sergi, Angeles Juarranz, Debasish Roy

Publications and Research

No abstract provided.

Examining The Roles Of Genetic And Environmental Factors In Drosophila Melanogaster Hematopoiesis And Innate Immune System, Minkyung Lee

Student Theses and Dissertations

Nearly 24 million people are affected by autoimmune diseases in the United States. Main causes of autoimmune diseases have been attributed to genetic predisposition and environmental exposure to chemicals such as hormones and pesticides. Due to the large population that are affected by autoimmune diseases, it is critical to understand the mechanisms behind them. In this study, we sought to explore both genetic and environmental factors that affect hematopoiesis, or the formation of specific blood cells, and immune system in Drosophila melanogaster. As Drosophila melanogaster have conserved pathways of hematopoiesis as humans, they were used as the model organism …

What We Do Not Know About Fungal Cell Adhesion Molecules, Peter N. Lipke

Publications and Research

There has been extensive research on structure and function of fungal cell adhesion molecules, but the most of the work has been about adhesins in Candida albicans and Saccharomyces cerevisiae. These yeasts are members of a single ascomycete order, and adhesion molecules from the six other fungal phyla are only sparsely described in the literature. In these other phyla, most of the research is at the cellular level, rather than at the molecular level, so there has been little characterization of the adhesion molecules themselves. A catalog of known adhesins shows some common features: high Ser/Thr content, tandem repeats, N- …

Egfr Polymorphisms In Drosophila Melanogaster, Stacie Chue, Neha Mehta, Samantha Poon, Heather Trazino

Publications and Research

No abstract provided.

Regulation Of The Tubulin Homolog Ftsz In Escherichia Coli, Monika S. Buczek

Dissertations, Theses, and Capstone Projects

Escherichia coli is a well-known pathogen, and importantly, a widely used model organism in all fields of biological sciences for cloning, protein purification, and as a model for Gram-negative bacterial species. And yet, researchers do not fully understand how this bacterium replicates and divides. Every year additional division proteins are discovered, which adds complexity to how we understand E. coli undergoes cell division. Due to their specific roles in cytokinesis, some of these proteins may be potential targets for development of antibacterials or bacteriostatics, which are much needed for fighting the current global antibacterial deficit. My thesis work focuses on …

Genetic Basis Of Larval Crystal Cell Quantity Variation In The Drosophila Genetic Reference Panel (Dgrp), Brian Tang

Student Theses and Dissertations

Crystal cells are one of three requisite hemocytes that take part in fighting infection and wound healing in Drosophila melanogaster (common fruit flies). The developmental genetics of crystal cell formation is only beginning to be discovered. To address this question, we performed a Genome-Wide Association Study (GWAS) on larval crystal cell number from 78 isolines of the Drosophila Genetic Reference Panel (DGRP) collection. The DGRP consists of naturally caught fruit flies that are inbred to near homozygosity with completely sequenced genomes. By placing the wandering third instar larvae under heatshock, a process that induces the melanization of crystal cells, …

Resveratrol And Pterostilbene Exhibit Anticancer Properties Involving The Downregulation Of Hpv Oncoprotein E6 In Cervical Cancer Cells, Kaushiki Chatterjee, Dina Alsharif, Christina Mazza, Palwasha Syar, Mohamed Al Sharif, Jimmie E. Fata

Publications and Research

Cervical cancer is one of the most common cancers in women living in developing countries. Due to a lack of affordable effective therapy, research into alternative anticancer compounds with low toxicity such as dietary polyphenols has continued. Our aim is to determine whether two structurally similar plant polyphenols, resveratrol and pterostilbene, exhibit anticancer and anti-HPV (Human papillomavirus) activity against cervical cancer cells. To determine anticancer activity, extensive in vitro analyses were performed. Anti-HPV activity, through measuring E6 protein levels, subsequent downstream p53 effects, and caspase-3 activation, were studied to understand a possible mechanism of action. Both polyphenols are effective agents …

Retinal Progenitor Cells Release Extracellular Vesicles Containing Developmental Transcription Factors, Microrna And Membrane Proteins, Jing Zhou, Alberto Benito-Martin, Jason Mighty, Lynne Chang, Shima Ghoroghi, Hao Wu, Madeline Wong, Sara Guariglia, Petr Baranov, Michael Young, Rajendra Ghardbaran, Mark Emerson, Milica Tesic Mark, Henrik Molina, M. Valeria Canto-Solar, Hector Peinado Selgas, Stephen Redenti

Publications and Research

A range of cell types, including embryonic stem cells, neurons and astrocytes have been shown to release extracellular vesicles (EVs) containing molecular cargo. Across cell types, EVs facilitate transfer of mRNA, microRNA and proteins between cells. Here we describe the release kinetics and content of EVs from mouse retinal progenitor cells (mRPCs). Interestingly, mRPC derived EVs contain mRNA, miRNA and proteins associated with multipotency and retinal development. Transcripts enclosed in mRPC EVs, include the transcription factors Pax6, Hes1, and Sox2, a mitotic chromosome stabilizer Ki67, and the neural intermediate filaments Nestin and GFAP. Proteomic analysis of EV content revealed retinogenic …

The Candida Albicans Stress Response Gene Stomatin-Like Protein 3 Is Implicated In Ros-Induced Apoptotic-Like Death Of Yeast Phase Cells, Karen A. Conrad, Ronald Rodriguez, Eugenia C. Salcedo, Jason M. Rauceo

Publications and Research

The ubiquitous presence of SPFH (Stomatin, Prohibitin, Flotillin, HflK/HflC) proteins in all domains of life suggests that their function would be conserved. However, SPFH functions are diverse with organism-specific attributes. SPFH proteins play critical roles in physiological processes such as mechanosensation and respiration. Here, we characterize the stomatin ORF19.7296/SLP3 in the opportunistic human pathogen Candida albicans. Consistent with the localization of stomatin proteins, a Slp3p-Yfp fusion protein formed visible puncta along the plasma membrane. We also visualized Slp3p within the vacuolar lumen. Slp3p primary sequence analyses identified four putative S-palmitoylation sites, which may facilitate membrane localization and are conserved features …

The Candida Albicans Stress Response Gene Stomatin-Like Protein 3 Is Implicated In Ros-Induced Apoptotic-Like Death Of Yeast Phase Cells, Karen A. Conrad, Ronald Rodriguez, Eugenia C. Salcedo, Jason M. Rauceo

Publications and Research

The ubiquitous presence of SPFH (Stomatin, Prohibitin, Flotillin, HflK/HflC) proteins in all domains of life suggests that their function would be conserved. However, SPFH functions are diverse with organism-specific attributes. SPFH proteins play critical roles in physiological processes such as mechanosensation and respiration. Here, we characterize the stomatin ORF19.7296/SLP3 in the opportunistic human pathogen Candida albicans. Consistent with the localization of stomatin proteins, a Slp3p-Yfp fusion protein formed visible puncta along the plasma membrane. We also visualized Slp3p within the vacuolar lumen. Slp3p primary sequence analyses identified four putative S-palmitoylation sites, which may facilitate membrane localization and are conserved features …

Mechanisms For Survival And Drug Resistance In Cancer Cells, Matthew B. Utter

Dissertations, Theses, and Capstone Projects

PART I

Prostate cells are hormonally driven to grow and divide. Typical treatments for prostate cancer involve blocking the hormone androgen from activating the androgen receptor (AR) and thus inhibit growth and proliferation of the cancer. Androgen deprivation therapy (ADT) can lead to the selection of cancer cells that grow and divide independently of androgen receptor activation. Prostate cancer cells that are insensitive to androgens commonly display metastatic phenotypes and reduced long-term survival of patients. In this study, we provide evidence that androgen-insensitive prostate cancer cells have elevated phospholipase D (PLD) activity relative to the androgen-sensitive prostate cancer cells. PLD …

Anti-Proliferative Effects Of Garcinia Fruits In Breast Cancer Cells, Harini Anandhi Senthilkumar

Dissertations, Theses, and Capstone Projects

Breast cancer continues to be the second leading cause of death in women, even with the recent advances in research that has led to an improved understanding of molecular pathways and targets. Increasing mortality due to recurrence and lack of targeted drugs, especially in aggressive breast cancer subtypes such as triple negative breast cancer, has gained attention from the research community. With nearly 50% of the commonly used cancer drugs being sourced from plants, bioactive small molecules derived from a natural origin have immense potential as therapeutics. This study focuses on the anti-proliferative activities of benzophenones isolated from the edible …

Cloning And Spatiotemporal Expression Of Xenopus Laevis Apolipoprotein Ci, Jyotsna Sridharan, Tomomi Haremaki, Daniel C. Weinstein

Publications and Research

Apolipoprotein CI (ApoCI) belongs to the Apolipoprotein superfamily, members of which are involved in lipid transport, uptake and homeostasis. Excessive ApoCI has been implicated in atherosclerosis and Alzheimer’s disease in humans. In this study we report the isolation of Xenopus laevis apoCI and describe the expression pattern of this gene during early development, using reverse transcription polymerase chain reaction and whole mount in situ hybridization. Xenopus apoCI is enriched in the dorsal ectoderm during gastrulation, and is subsequently expressed in sensory placodes, neural tube and cranial neural crest. These data suggest as yet uncharacterized roles for ApoCI during early vertebrate …

Target Engagement Imaging Of Parp Inhibitors In Small-Cell Lung Cancer, Brandon Carney, Susanne Kossatz, Benjamin H. Lok, Valentina Schneeberger, Kishore K. Gangangari, Naga Vara Kishore Pillarsetty, Wolfgang A. Weber, Charles M. Rudin, John T. Poirier, Thomas Reiner

Publications and Research

Insufficient chemotherapy response and rapid disease progression remain concerns for smallcell lung cancer (SCLC). Oncologists rely on serial CT scanning to guide treatment decisions, but this cannot assess in vivo target engagement of therapeutic agents. Biomarker assessments in biopsy material do not assess contemporaneous target expression, intratumoral drug exposure, or drug-target engagement. Here, we report the use of PARP1/2-targeted imaging to measure target engagement of PARP inhibitors in vivo. Using a panel of clinical PARP inhibitors, we show that PARP imaging can quantify target engagement of chemically diverse small molecule inhibitors in vitro and in vivo. We measure PARP1/2 inhibition …

Collective Adhesion And Displacement Of Retinal Progenitor Cells Upon Extracellular Matrix Substrates Of Transplantable Biomaterials, Ankush Thakur, Shawn Mishra, Juan Pena, Jing Zhou, Stephen Redenti, Robert Majeska, Maribel Vazquez

Publications and Research

Strategies to replace retinal photoreceptors lost to damage or disease rely upon the migration of replacement cells transplanted into sub-retinal spaces. A significant obstacle to the advancement of cell transplantation for retinal repair is the limited migration of transplanted cells into host retina. In this work, we examine the adhesion and displacement responses of retinal progenitor cells on extracellular matrix substrates found in retina as well as widely used in the design and preparation of transplantable scaffolds. The data illustrate that retinal progenitor cells exhibit unique adhesive and displacement dynamics in response to poly-l-lysine, fibronectin, laminin, hyaluronic acid, and Matrigel. …

The Role Of Mdm2 In Dna Damage Signaling, Stanley Tam

Theses and Dissertations

The overexpression of the oncogene MDM2 is common in a variety of human cancers. MDM2 overexpression is known to increase genome instability in cells by delaying DNA double strand break repair and γH2AX levels. This study explores the knockdown of MDM2 and how it may affect DNA damage signaling.