Medical Molecular Biology Commons^™

Alzheimer's And Amyloid Beta: Amyloidogenicity And Tauopathy Via Dyshomeostatic Interactions Of Amyloid Beta, Jordan Tillinghast

Senior Honors Theses

This paper reviews functions of Amyloid-β (Aβ) in healthy individuals compared to the consequences of aberrant Aβ in Alzheimer’s disease (AD). As extraneuronal Aβ accumulation and plaque formation are characteristics of AD, it is reasonable to infer a pivotal role for Aβ in AD pathogenesis. Establishing progress of the disease as well as the mechanism of neurodegeneration from AD have proven difficult (Selkoe, 1994). This thesis provides evidence suggesting the pathogenesis of AD is due to dysfunctional neuronal processes involving Aβ’s synaptic malfunction, abnormal interaction with tau, and disruption of neuronal homeostasis. Significant evidence demonstrates that AD symptoms are partially …

It's A Hard Nacht Life: Understanding How Nlrp12 Ticks, Abbigale Julia Brown

Graduate Theses/Dissertations

The protein NOD- like receptor pyrin domain containing 12 (NLRP12) comes from a family of protein receptors with a wide range of functions including fertility as well as anti-inflammatory properties. The biological role of NLRP12 is poorly understood: research on the mechanisms behind its function and/or activation remains contradictory between different cell models. Current research suggests its involvement in a multi-protein complex named the inflammasome. The alternative hypothesis that has also been proposed is that NLRP12 is not a part of the inflammasome, rather it negatively regulates a transcription factor known as NF-��B down stream of Toll-like receptors. NLRP12 is …

Identification And Molecular Analysis Of Dna In Exosomes, Jena Tavormina

Dissertations and Theses (Open Access)

Exosomes are heterogeneous nanoparticles 50-150nm in diameter. Exosomes contain many functional cargo components, such as protein, DNA, and RNA. While protein and RNA exosome content has been extensively studied, very little work has been done to characterize exosomal DNA. Here, we demonstrate that exosomal DNA is heterogeneous and its packaging into exosomes is dependent on the cell of origin. Furthermore, through a rigorous assessment of various isolation methods, we identify Size Exclusion Chromatography (SEC) as the best method for the isolation of exosomal DNA for downstream applications. Additionally, we evaluate the methylation status of exosomal DNA and demonstrate that exosomal …

Identifying Exosomes In Oral Squamous Cell Carcinoma With Efirm, Bram Holladay

Student Scholarship

Oral Squamous Cell Carcinoma (OSCC) affects 53,000 Americans each year making it the sixth most common cancer in the United States. The incidence rate may be even higher since current screening methods are underutilized and physical examinations can misdiagnose malignant oral tumors as benign inflammatory lesions. Recent advances in genetic, protein, and extracellular vesicle biomarker detection techniques can monitor the transformation of healthy cells into tumors before terminal stages arise. Biomarkers can be easily extracted from biofluids such as saliva making them less invasive than traditional tissue biopsies. One biomarker prevalent in OSCC is exosomes, which are extracellular vesicles that …

A Physiologically-Based Pharmacokinetic Model For Targeting Calcitriol-Conjugated Quantum Dots To Inflammatory Breast Cancer Cells., James Forder, Mallory Smith, Margot Wagner, Rachel J. Schaefer, Jonathan Gorky, Kenneth L. Van Golen, Anja Nohe, Prasad Dhurjati

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Quantum dots (QDs) conjugated with 1,25 dihydroxyvitamin D3 (calcitriol) and Mucin-1 (MUC-1) antibodies (SM3) have been found to target inflammatory breast cancer (IBC) tumors and reduce proliferation, migration, and differentiation of these tumors in mice. A physiologically-based pharmacokinetic model has been constructed and optimized to match experimental data for multiple QDs: control QDs, QDs conjugated with calcitriol, and QDs conjugated with both calcitriol and SM3 MUC1 antibodies. The model predicts continuous QD concentration for key tissues in mice distinguished by IBC stage (healthy, early-stage, and late-stage). Experimental and clinical efforts in QD treatment of IBC can be augmented by in …

Delineating The Mechanisms Of Misfolded Endoplasmic Reticulum (Er) Luminal Protein Retrotranslocation For Er-Associated Degradation, Christina Oikonomou

Theses and Dissertations (ETD)

Secreted, plasma membrane, and resident proteins of the secretory pathway are synthesized in the endoplasmic reticulum (ER) where they undergo post-translational modifications, oxidative folding, and subunit assembly in tightly monitored processes. An ER quality control (ERQC) system oversees protein maturation and ensures that only those reaching their native state will continue trafficking into the secretory pathway to reach their final destinations. Proteins that fail quality control must be recognized and eliminated to maintain ER proteostasis. The ER-associated degradation (ERAD) was discovered nearly 30 years ago and entails the identification of improperly matured secretory pathway proteins and their retrotranslocation to the …

Structural And Functional Analysis Of Parameters Governing Tankyrase-1 Interaction With Telomeric Repeat-Binding Factor 1 And Gdp-Mannose 4,6-Dehydratase., Travis Eisemann, Marie-France Langelier, John M. Pascal

Department of Biochemistry and Molecular Biology Faculty Papers

Human tankyrase-1 (TNKS) is a member of the poly(ADPribose) polymerase (PARP) superfamily of proteins that posttranslationally modify themselves and target proteins with ADP-ribose (termed PARylation). The TNKS ankyrin repeat domain mediates interactions with a growing number of structurally and functionally diverse binding partners, linking TNKS activity to multiple critical cell processes, including Wnt signaling, Golgi trafficking, and telomere maintenance. However, some binding partners can engage TNKS without being modified, suggesting that separate parameters influence TNKS interaction and PARylation. Here, we present an analysis of the sequence and structural features governing TNKS interactions with two model binding partners: The PARylated partner …

Slc36a1-Mtorc1 Signaling Drives Acquired Resistance To Cdk4/6 Inhibitors., Akihiro Yoshida, Yiwen Bu, Shuo Qie, John Wrangle, E. Ramsay Camp, E. Starr Hazard, Gary Hardiman, Renée De Leeuw, Karen E. Knudsen, J. Alan Diehl

Department of Cancer Biology Faculty Papers

The cyclin-dependent kinase 4/6 (CDK4/6) kinase is dysregulated in melanoma, highlighting it as a potential therapeutic target. CDK4/6 inhibitors are being evaluated in trials for melanoma and additional cancers. While beneficial, resistance to therapy is a concern, and the molecular mechanisms of such resistance remain undefined. We demonstrate that reactivation of mammalian target of rapamycin 1 (mTORC1) signaling through increased expression of the amino acid transporter, solute carrier family 36 member 1 (SLC36A1), drives resistance to CDK4/6 inhibitors. Increased expression of SLC36A1 reflects two distinct mechanisms: (i) Rb loss, which drives SLC36A1 via reduced suppression of E2f; (ii) fragile X …

Heme And Hemoglobin Utilization By Mycobacterium Tuberculosis., Avishek Mitra, Ying-Hui Ko, Gino Cingolani, Michael Niederweis

Department of Biochemistry and Molecular Biology Faculty Papers

Iron is essential for growth of Mycobacterium tuberculosis (Mtb), but most iron in the human body is stored in heme within hemoglobin. Here, we demonstrate that the substrate-binding protein DppA of the inner membrane Dpp transporter is required for heme and hemoglobin utilization by Mtb. The 1.27 Å crystal structure of DppA shows a tetrapeptide bound in the protein core and a large solvent-exposed crevice for heme binding. Mutation of arginine 179 in this cleft eliminates heme binding to DppA and prevents heme utilization by Mtb. The outer membrane proteins PPE36 and PPE62 are also required for heme and hemoglobin …

Development Of Substrate Degradation Enzyme Therapy For Mucopolysaccharidosis Iva Murine Model., Kazuki Sawamoto, Shunji Tomatsu

Department of Pediatrics Faculty Papers

Mucopolysaccharidosis IVA (MPS IVA) is caused by a deficiency of the lysosomal enzyme N-acetylgalactosamine-6-sulfate sulfatase (GALNS). Conventional enzyme replacement therapy (ERT) is approved for MPS IVA. However, the fact that the infused enzyme cannot penetrate avascular lesions in cartilage leads to minimal impact on the bone lesion. Moreover, short half-life, high cost, instability, and narrow optimal pH range remain unmet challenges in ERT. Thermostable keratanase, endo-β-N-acetylglucosaminidase, has a unique character of a wide optimal pH range of pH 5.0-7.0. We hypothesized that this endoglycosidase degrades keratan sulfate (KS) polymer in circulating blood and, therefore, ameliorates the accumulation of KS in …

Generation Of An Oncolytic Adenovirus Targeting The Cxcr4 And Cxcr7 Chemokine Receptors In Breast Cancer, Samia Melissa O'Bryan

LSU Doctoral Dissertations

Breast cancer is the most diagnosed cancer in women under 60 and the second most diagnosed cancer in women over 60. While treatments for localized breast cancer are quite successful with high survival rates at 99%, advanced breast cancer remains hard to treat with a nearly 75% decrease in survival. Current treatments are inefficient at treating advanced stages of breast cancer, and thus, new therapies are sorely needed to address the complexity of advanced stage breast cancer. The ideal therapy would be capable of systemic administration, targets cancer cells and spares normal tissue. Oncolytic adenovirus is an ideal therapeutic vector …

N-Glycosylation-Defective Splice Variants Of Neuropilin-1 Promote Metastasis By Activating Endosomal Signals, Xiuping Huang, Qing Ye, Min Chen, Aimin Li, Wenting Mi, Yuxin Fang, Yekaterina Y. Zaytseva, Kathleen L. O'Connor, Craig W. Vander Kooi, Side Liu, Qing-Bai She

Markey Cancer Center Faculty Publications

Neuropilin-1 (NRP1) is an essential transmembrane receptor with a variety of cellular functions. Here, we identify two human NRP1 splice variants resulting from the skipping of exon 4 and 5, respectively, in colorectal cancer (CRC). Both NRP1 variants exhibit increased endocytosis/recycling activity and decreased levels of degradation, leading to accumulation on endosomes. This increased endocytic trafficking of the two NRP1 variants, upon HGF stimulation, is due to loss of N-glycosylation at the Asn150 or Asn261 site, respectively. Moreover, these NRP1 variants enhance interactions with the Met and β1-integrin receptors, resulting in Met/β1-integrin co-internalization and co-accumulation on endosomes. This provides persistent …

Endothelial Iqgap1 Regulates Leukocyte Transmigration By Directing The Lbrc To The Site Of Diapedesis, David P. Sullivan, Prarthana J. Dalal, Fanny Jaulin, David B. Sacks, Geri Kreitzer, William A. Muller

Publications and Research

Transendothelial migration (TEM) of leukocytes across the endothelium is critical for inflammation. In the endothelium, TEM requires the coordination of membrane movements and cytoskeletal interactions, including, prominently, recruitment of the lateral border recycling compartment (LBRC). The scaffold protein IQGAP1 was recently identified in a screen for LBRC-interacting proteins. Knockdown of endothelial IQGAP1 disrupted the directed movement of the LBRC and substantially reduced leukocyte TEM. Expression of truncated IQGAP1 constructs demonstrated that the calponin homology domain is required for IQGAP1 localization to endothelial borders and that the IQ domain, on the same IQGAP1 polypeptide, is required for its function in TEM. …

Natural Autoantibodies: Origin, Function And Utility For Diagnosis Of Disease, Abhirup Sarkar

Graduate School of Biomedical Sciences Theses and Dissertations

Autoantibodies (aAbs) by the simplest definitions have been described as antibodies against self-antigens and were exclusively associated with autoimmune diseases. Eventually, studies demonstrated that they are abundant in the blood of all human sera, regardless of age, gender, or the presence or absence of disease, and were thus named as ‘natural autoantibodies’. The underlying reason for their ubiquity has remained elusive, but we have hypothesized that they are responsible for clearing blood-borne cell and tissue debris generated under conditions of health and disease. To test this, we chose to use two widely different disease model systems, namely neurodegenerative diseases and …

Cleavage And Sub-Cellular Redistribution Of Nuclear Pore Protein 98 By Coxsackievirus B3 Protease 2a Impairs Cardioprotection., Paul J. Hanson, Al Rohet Hossain, Ye Qiu, Huifang M. Zhang, Guangze Zhao, Cheng Li, Veena Lin, Saheedat Sulaimon, Marli Vlok, Gabriel Fung, Victoria H. Chen, Eric Jan, Bruce M. Mcmanus, David J. Granville, Decheng Yang

College of Population Health Faculty Papers

Myocarditis, inflammation of the heart muscle, affects all demographics and is a major cause of sudden and unexpected death in young people. It is most commonly caused by viral infections of the heart, with coxsackievirus B3 (CVB3) being among the most prevalent pathogens. To understand the molecular pathogenesis of CVB3 infection and provide strategies for developing treatments, we examined the role of a key nuclear pore protein 98 (NUP98) in the setting of viral myocarditis. NUP98 was cleaved as early as 2 h post-CVB3 infection. This cleavage was further verified through both the ectopic expression of viral proteases and in …

Structural Basis For The Homotypic Fusion Of Chlamydial Inclusions By The Snare-Like Protein Inca., Gino Cingolani, Michael Mccauley, Anna Lobley, Alexander J Bryer, Jordan Wesolowski, Deanna L Greco, Ravi K Lokareddy, Erik Ronzone, Juan R Perilla, Fabienne Paumet

Department of Biochemistry and Molecular Biology Faculty Papers

Many intracellular bacteria, including Chlamydia, establish a parasitic membrane-bound organelle inside the host cell that is essential for the bacteria's survival. Chlamydia trachomatis forms inclusions that are decorated with poorly characterized membrane proteins known as Incs. The prototypical Inc, called IncA, enhances Chlamydia pathogenicity by promoting the homotypic fusion of inclusions and shares structural and functional similarity to eukaryotic SNAREs. Here, we present the atomic structure of the cytoplasmic domain of IncA, which reveals a non-canonical four-helix bundle. Structure-based mutagenesis, molecular dynamics simulation, and functional cellular assays identify an intramolecular clamp that is essential for IncA-mediated homotypic membrane fusion during …

Investigating Trail Sensitivity In Platinum-Resistant Ovarian Cancer, Nicholas Pathoulas

All College Thesis Program, 2016-2019

Ovarian cancer is the deadliest gynecologic malignancy in the United States. While these tumors may have a promising initial response to platinum-based chemotherapies, the patient’s prognosis is commonly hindered by the development of platinum resistant cancer. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been implicated as a potential treatment for many cancers based on its tumor selective nature. Combination therapies with TRAIL and platinum drugs have been shown to increase apoptosis and have been used in a variety of clinical trials, which have thus far failed to pass phase II.1 Researchers have not yet elucidated the complex mechanism(s) of TRAIL …

Development Of A Sonically Powered Biodegradable Nanogenerator For Bone Regeneration, Avi Patel

Honors Scholar Theses

Background: Reconstruction of bone fractures and defects remains a big challenge in orthopedic surgery. While regenerative engineering has advanced the field greatly using a combination of biomaterial scaffolds and stem cells, one matter of difficulty is inducing osteogenesis in these cells. Recent works have shown electricity’s ability to promote osteogenesis in stem cell lines when seeded in bone scaffolds; however, typical electrical stimulators are either (a) externally housed and require overcomplex percutaneous wires be connected to the implanted scaffold or (b) implanted non-degradable devices which contain toxic batteries and require invasive removal surgeries.

Objective: Here, we establish a biodegradable, piezoelectric …

Yeast Mitochondrial Protein Pet111p Binds Directly To Two Distinct Targets In Cox2 Mrna, Suggesting A Mechanism Of Translational Activation, Julia L Jones, Katharina B. Hofmann, Andrew T. Cowan, Dmitry Temiakov, Patrick Cramer, Michael Anikin

Department of Biochemistry and Molecular Biology Faculty Papers

The genes in mitochondrial DNA code for essential subunits of the respiratory chain complexes. In yeast, expression of mitochondrial genes is controlled by a group of gene-specific translational activators encoded in the nucleus. These factors appear to be part of a regulatory system that enables concerted expression of the necessary genes from both nuclear and mitochondrial genomes to produce functional respiratory complexes. Many of the translational activators are believed to act on the 5'-untranslated regions of target mRNAs, but the molecular mechanisms involved in this regulation remain obscure. In this study, we used a combination of in vivo and in …

Identification Of Anaerobes In Clinical Specimens Comparison Between The Rapid Ana Ii System And The Bruker Maldi-Tof Ms System Utilized In The Clinical Laboratory, Raymond Chow

Natural Sciences and Mathematics | Clinical Laboratory Sciences

Matrix-Assisted Laser Desorption and Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) has been revealed as an invaluable platform for identifying anaerobic bacteria in the clinical laboratory over traditional methods such as the RapID ANA II System.

A qualitative comparison is made, through the analysis of methodologies and specifications, to determine whether the RapID ANA II system or Bruker MALDI-TOF MS is more suitable for identifying anaerobic organism in the clinical laboratory. Based on the data reviewed, the MALDI-TOF MS is a more intuitive platform within the clinical laboratory due to its increased specificity, cost-effectiveness, and shorten turnaround time for the identification …