Cell Biology Commons^™

N-Terminal Domain Of Human Uracil Dna Glycosylase (Hung2) Promotes Targeting To Uracil Sites Adjacent To Ssdna-Dsdna Junctions, Brian P Weiser, Gaddiel Rodriguez, Philip A Cole, James T Stivers

Rowan-Virtua School of Osteopathic Medicine Departmental Research

The N-terminal domain (NTD) of nuclear human uracil DNA glycosylase (hUNG2) assists in targeting hUNG2 to replication forks through specific interactions with replication protein A (RPA). Here, we explored hUNG2 activity in the presence and absence of RPA using substrates with ssDNA-dsDNA junctions that mimic structural features of the replication fork and transcriptional R-loops. We find that when RPA is tightly bound to the ssDNA overhang of junction DNA substrates, base excision by hUNG2 is strongly biased toward uracils located 21 bp or less from the ssDNA-dsDNA junction. In the absence of RPA, hUNG2 still showed an 8-fold excision bias …

Uplc-Ms/Ms Analysis Of Dextromethorphan-O-Demethylation Kinetics In Rat Brain Microsomes, Barent N. Dubois, Reza Mehvar

Pharmacy Faculty Articles and Research

Formation of dextrorphan (DXT) from dextromethorphan (DXM) has been widely used to assess cytochrome P450 2D (CYP2D) activity. Additionally, the kinetics of CYP2D activity have been well characterized in the liver microsomes. However, studies in brain microsomes are limited due to the lower microsomal content and abundance of CYP2D in the brain relative to the liver. In the present study, we developed a micro-scale enzymatic incubation method, coupled with a sensitive UPLC-MS/MS assay for the quantitation of the rate of DXT formation from DXM in brain microsomes. Rat brain microsomes were incubated with different concentrations of DXM for various times. …

Cellular Mechanisms Of Slime Gland Refilling In Pacific Hagfish (Eptatretus Stoutii), Sarah Schorno, Todd E. Gillis, Douglas S. Fudge

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Hagfishes use their defensive slime to ward off gill-breathing predators. Slime gland refilling is a surprisingly slow process, and previous research has shown that the composition of the slime exudate changes significantly during refilling, which likely has consequences for the functionality of the slime. This study set out to expand our understanding of slime gland refilling by examining the cellular processes involved in refilling of the glands, as well as determining where in the gland the main slime cells – the gland thread cells and gland mucous cells – arise. Slime glands were electro-stimulated to exhaust their slime stores, left …

Astromimetics: The Dawn Of A New Era For (Bio)Materials Science?, Vuk Uskoković, Victoria M. Wu

Pharmacy Faculty Articles and Research

Composite, multifunctional fine particles are likely to be at the frontier of materials science in the foreseeable future. Here we present a submicron composite particle that mimics the stratified structure of the Earth by having a zero-valent iron core, a silicate/silicide mantle, and a thin carbonaceous crust resembling the biosphere and its biotic deposits. Particles were formulated in a stable colloidal form and made to interact with various types of healthy and cancer cells in vitro. A selective anticancer activity was observed, promising from the point of view of the intended use of the particles for tumor targeting across the …

Double-Stranded Rna Binding Protein, Staufen, Is Required For The Initiation Of Rnai In Coleopteran Insects, June-Sun Yoon, Kanakachari Mogilicherla, Dhandapani Gurusamy, Xien Chen, Shankar C. R. R. Chereddy, Subba R. Palli

Entomology Faculty Publications

RNA interference (RNAi) is being used to develop methods to control pests and disease vectors. RNAi is robust and systemic in coleopteran insects but is quite variable in other insects. The determinants of efficient RNAi in coleopterans, as well as its potential mechanisms of resistance, are not known. RNAi screen identified a double-stranded RNA binding protein (StaufenC) as a major player in RNAi. StaufenC homologs have been identified in only coleopteran insects. Experiments in two coleopteran insects, Leptinotarsa decemlineata and Tribolium castaneum, showed the requirement of StaufenC for RNAi, especially for processing of double-stranded RNA (dsRNA) to small interfering …

Structural And Functional Characterization Of Hyper-Phosphorylated Grk5 Protein Expressed From E. Coli, Joseph M. Krampen, John Tesmer, Qiuyan Chen

The Summer Undergraduate Research Fellowship (SURF) Symposium

G protein-coupled receptor (GPCR) kinases (GRKs) are proteins in the cell responsible for regulating GPCRs located on the cell membrane. GRKs regulate active GPCRs by phosphorylating them at certain sites which causes them to stop normal signaling on the membrane. This ultimately affects how the cell responds to its environment. GRK5 is a kinase of particular interest due to its involvement in the pathology of diseases such as cardiac failure, cancers, and diabetes. Understanding the structure and function of GRK5 is essential for discovering ways to manipulate its behavior with these diseases, but not much is known about how GRK5 …

Targeting Pro-Inflammatory Function Of Microglia Using Small Molecules To Combat Neurodegeneration, Gabrielle C. Williams, Priya Prakash, Gaurav Chopra

The Summer Undergraduate Research Fellowship (SURF) Symposium

Microglia are the brain’s resident immune cells that are responsible for maintaining homeostasis in healthy conditions. During injury or infection, resting microglia get activated and produce pro-inflammatory cytokines such as IL-1b, IL-1a, IL-6, etc. along with reactive oxygen species like nitric oxide (NO) to combat neuroinflammatory diseases such as Alzheimer’s disease (AD). Inflammation is characterized by the activation of resident-immune cells in the brain called microglia that respond to the eat-me signals released by the toxic amyloid beta peptides as well as the dying neurons in the microenvironment. Recent studies have shown that activated microglia induce neuronal death by secreting …

The Role Of Developmental Timing Regulators In Progenitor Proliferation And Cell Fate Specification During Mammalian Neurogenesis, Jennifer S. Romer-Seibert

Graduate School of Biomedical Sciences Theses and Dissertations

Developmental timing is a key aspect of tissue and organ formation in which distinct cell types are generated through a series of steps from common progenitors. These progenitors undergo specific changes in gene expression that signifies both a distinct progenitor type and developmental time point that thereby specifies a particular cell fate at that stage of development. The nervous system is an important setting for understanding developmental timing because different cell types are produced in a certain order and the switch from stem cells to progenitors requires precise timing and regulation. Notable examples of such regulatory molecules include the RNA-binding …

Inhibition Of Ribosome Biogenesis Through Genetic And Chemical Approaches, Leonid Anikin

Graduate School of Biomedical Sciences Theses and Dissertations

In order to maintain the ability to generate proteins, proliferating cells must continuously generate ribosomes, designating up to 80% of their energy to ribosome biogenesis (RBG). RBG involves transcription of rDNA by RNA polymerases I (Pol I) and III (Pol III), expression of approximately 80 ribosomal proteins, and assembly of these components in a process referred to as ribosome maturation. During maturation, the Pol I transcribed 47S pre-rRNA undergoes a number of processing events, while simultaneously interacting with processing factors and ribosomal proteins that drive pre-ribosome assembly. Inhibition of RBG has become one of the pursued targets for cancer therapy …

Insight Into Translational Activation In Yeast Mitochondria, Julia Lynn Jones

Graduate School of Biomedical Sciences Theses and Dissertations

Mitochondrial function depends on over a thousand proteins, of which the majority are nuclear DNA-encoded and approximately one percent are mitochondrial DNA-encoded. The mitochondrial DNA of Saccharomyces cerevisiae contains eight protein-encoding genes, seven of which are required for proper function of the respiratory complexes and one encodes a ribosomal protein. The bigenomic nature of the oxidative phosphorylation complexes requires coordinated expression and regulation from both the nuclear and the mitochondrial genomes. It is currently unclear how this regulatory network operates. However, it is thought that nuclear genome-encoded messengers localized to the mitochondria aid in this coordination.

A family of proteins …

Uncoupling The Folding And Binding Of An Intrinsically Disordered Protein, Anusha Poosapati, Emily Gregory, Wade M. Borcherds, Lucia B. Chemes, Gary Daughdrill

Molecular Biosciences Faculty Publications

The relationship between helical stability and binding affinity was examined for the intrinsically disordered transactivation domain of the myeloblastosis oncoprotein, c-Myb, and its ordered binding partner, KIX. A series of c-Myb mutants was designed to either increase or decrease helical stability without changing the binding interface with KIX. This included a complimentary series of A, G, P, and V mutants at three non-interacting sites. We were able to use the glycine mutants as a reference state and show a strong correlation between binding affinity and helical stability. The intrinsic helicity of c-Myb is 21%, and helicity values of the …

Chronic Cadmium Exposure Alters Erα Dependency And Drug Sensitivity Of Breast Cancer Cells, Mathew Bloomfield

Dissertations, Masters Theses, Capstones, and Culminating Projects

The global prevalence of breast cancer in women illustrates the importance of identifying factors that contribute to disease onset and progression. Endogenous and environmental agents that interact with estrogen receptor alpha (ERα) have been shown to play a role in breast cancer etiology. Evidence from epidemiological studies and animal models has suggested that cadmium, a heavy metal that can activate ERα, contributes to the development and progression of breast cancer. Additionally, our lab showed that chronic cadmium exposure altered the expression of several ERα-responsive genes and increased the malignancy of MCF7 breast cancer cells. Although these studies support cadmium’s function …

Anti-Inflammatory Activity Of Phenolic And Volatile Compounds In Cranberries (Vaccinium Macrocarpon L), Katherine Moore

Graduate Theses and Dissertations

The primary objective of this study was to compare the anti-inflammatory effects of phenolic and volatile compounds extracted from cranberries. The Griess Reagent System assay was used to measure the in vitro anti-inflammatory capabilities of cranberry phenolic and volatile extracts on RAW 264.7 mouse macrophage cells. This study tested the anti-inflammatory capabilities of the cranberry phenolic and volatile extracts before, as a preventative treatment, and after, as a means of treating pre-existing inflammation, inducing inflammation with lipopolysaccharide (LPS). All experiments were conducted in the following manner, varying only in whether treated with the extracts before or after LPS: 1 x …

Determining The Effect Of Locally Delivered Bioactive Modulators On Macrophage Activation At The Implantation Site Of Different Biomaterials In Rats, Kamel Alkhatib

Graduate Theses and Dissertations

Altering the foreign body reaction by targeting macrophages has been of interest in the biomaterials field to improve the integration of longevity of implanted biomedical devices. The objective of this dissertation was to study the effect of locally delivered bioactive modulators on macrophage activation at the implantation site of different biomaterials in rats. Iloprost, a prostacyclin analog, was tested for its ability to direct macrophages to their pro-wound healing phenotype after the implantation of microdialysis probe in the subcutaneous space of male Sprague Dawley rats. This study showed that iloprost can shift macrophage activation states in vivo to the pro-wound …

Effect Of Morinda Citrifolia (Noni)-Enriched Diet On Hepatic Heat Shock Protein And Lipid Metabolism-Related Genes In Heat Stressed Broiler Chickens, Joshua Flees

Graduate Theses and Dissertations

Heat stress (HS) has been reported to alter fat deposition in broilers, however the underlying molecular mechanisms are not well-defined; therefore, the objectives of the current study were to: (1) determine the effects of acute (2 h) and chronic (3 wk) HS on the expression of key molecular signatures involved in hepatic lipogenic and lipolytic programs; and (2) assess if diet supplementation with dried Noni medicinal plant (0.2% of the diet) modulates these effects. Broilers (n=480 males, 1 d) were randomly assigned to 12 environmental chambers, subjected to two environmental conditions (HS at 35°C vs. thermoneutral condition [TN] at 24°C) …

Dissecting The Mechanism Of Action Of A Novel Antifungal Peptide, Cody Bullock

Graduate Theses and Dissertations

There is an urgent need for novel treatments for Candida infections. The utility of antimicrobial peptides for antifungal therapy has garnered interest in recent years. One promising family of peptides is the Histatins, a family of naturally-occurring peptides secreted into the oral cavity that display antimicrobial activity. Histatin 5 is a twenty-four amino acid peptide with strong antifungal activity. Studies from our laboratory have identified a small histatin-derived peptide, KM29, that yields fungicidal activity 10-fold greater than Histatin 5 against multiple Candida species. Our laboratory has focused on understanding the mechanism of action of KM29 to further develop it as …

Assessment Of Melanocyte-Specific Primary And Memory Autoimmune Responses In Vitiligo-Prone Smyth And Vitiligo-Susceptible, Non-Expressing Brown Line Chickens, Daniel Morales Falcon

Graduate Theses and Dissertations

Vitiligo is an acquired de-pigmentation disorder characterized by the post-natal loss of epidermal melanocytes (pigment-producing cells) resulting in the appearance of white patches in the skin. The Smyth line of chicken is the only model for vitiligo that shares all the characteristics of the human condition including: spontaneous post-natal loss of melanocytes, interactions between genetic, environmental and immunological factors and associations with other autoimmune diseases. In addition, an avian model for vitiligo has the added benefit of an easily accessible target tissue (a growing feather) that allows for the repeated sampling of an individual and thus the continuous monitoring of …

The Role Of Rad4 In Dna Repair And Its Interplay With Telomeres In Tetrahymena Thermophila, Emily Nischwitz

Graduate Theses/Dissertations

Telomeres are repetitive parts of the genome that act as a protective end cap to the chromosomes. Telomeres are critical to the integrity and stability of the genome, therefore, ensuring that their sequence is maintained, even after damage, is crucial. Much of the pioneering work responsible for explaining telomeres has been conducted in ciliates, specifically in Tetrahymena thermophila. Telomeres in T. thermophila have a high amount of tandem thymine repeats (GGGGTT) and, thus, are susceptible to ultraviolet light (UV) induced lesions called pyrimidine dimers, which must be repaired by nucleotide excision repair (NER). In humans, Xeroderma Pigmentosum C (XPC) …

Evaluation Of Endothelial Cell Responses To Elevated Glucose, Gabriella Sugerman

Master's Theses

Developing a tissue-engineered Blood Vessel Mimic (BVM) to represent diabetic macrovascular disease could expedite design of new vascular devices specifically tailored to diabetic patients. In contribution toward this model, this thesis assessed Human Umbilical Vein Endothelial Cell (HUVEC) responses to high glucose conditions. Interleukin 6 (IL-6) and Cluster of Differentiation 36 (CD36) were selected to signify oxidative stress activity, a hallmark of diabetic macrovascular disease. Next, activity of potential reference genes B2M, HPRT1, and ACTB was assessed. All genes were found to exceed acceptable variability, so the E-ΔC T method of data analysis was selected. Next, cellular responses to high …

Characterization Of Theranostic Peptides For Glioblastoma Multiforme, Aaron Mellesmoen

All NMU Master's Theses

Glioblastoma multiforme (GBM) is a type of primary CNS tumor in which viable treatment options do not exist. Standard of care including tumor resection, chemotherapy, and radiation does little to extend the 5-year survival expectancy past 5.1%. Herein, two small-peptide molecules with inherent antitumor activity, blood-brain barrier permeability, and capability for tumor-specific drug deliverance and intraoperative visualization (termed theranostic) were of focus. Confocal microscopy was employed to characterize in vitro specificity of chlorotoxin, a 4 kDa scorpion venom peptide, and rBSG, the recombinant 25 kDa non-glycosylated extracellular domain of extracellular matrix metalloproteinase inducer (EMMPRIN; Basigin) isoform …