Molecular Biology Commons^™

Wee1 And Cell Size Control In Fission Yeast By The Protein Kinase Cdr2, Rachel Berg-Murante

Dartmouth College Ph.D Dissertations

The mechanisms that govern cell size have long been topics of study in the field of cell biology. In eukaryotic cells this size control is tied to checkpoints, a set threshold of minimum necessary growth linked to cyclin dependent kinase activity regulation. In the fission yeast Schizosaccharomyces pombe, the Cdk1 regulatory network is conserved, and G2/M represents the major size checkpoint. Prior to mitosis, Cdk1 is inhibited by phosphorylation applied by Wee1 during G2 phase. Once S. pombe cells have satisfied the size checkpoint, Cdk1 is activated through dephosphorylation by Cdc25. Wee1 is a dose-dependent regulator of mitotic entry …

Optimizing The Expression Of Polyethylene Terephtalate Hydrolase-Encoding Synthetic Gene In Escherichia Coli Arctic Express (De3), Jocelyn Nataniel, Maria Ulfah, Dini Achnafani, Niknik Nurhayati, Gabriela Christy Sabbathini, Sri Rezeki Wulandari, Abinawanto Abinawanto, Is Helianti

Makara Journal of Science

The waste of polyethylene terephthalate (PET) plastic waste in Indonesia is a pressing concern due to its slow degradation and potential environmental damage. One promising solution is to utilize polyethylene terephthalate hydrolase from Ideonella sakaiensis (IsPETase), an enzyme that specifically degrades PET. However, inducing the expression of IsPETase synthetic gene in Escherichia coli BL21 (DE3) has been challenging because much of it remains insoluble. This study aimed to express IsPETase in E. coli Arctic Express (DE3) and optimize the conditions to enhance its production. First, pET22b(+)pelB-IsPETase was inserted into E. coli Arctic Express (DE3). The …

Roles Of Mitochondrial Chchd2 And Gpcr-Associated Β-Arrestin2 In The Pathogenesis Of Lewy Body Disorders, Teresa R. Kee

USF Tampa Graduate Theses and Dissertations

Coiled-coil-helix-coiled-coil-helix domain containing 2 (CHCHD2) is a mitochondrial protein that plays important roles in cristae structure, oxidative phosphorylation, and apoptosis. Multiple mutations in CHCHD2 have been associated with Lewy body disorders (LBDs), such as Parkinson’s disease (PD) and dementia with Lewy bodies (DLB), with the CHCHD2T61I mutation being the most widely studied. We generated the first transgenic mouse models expressing human CHCHD2WT and the PD-linked CHCHD2T61I mutation driven by the mPrP promoter. CHCHD2T61I Tg, but not CHCHD2WT Tg mice exhibit perinuclear mitochondrial aggregates, neuroinflammation, and have impaired long-term synaptic plasticity associated with synaptic dysfunction. Dopaminergic neurodegeneration, a hallmark of PD, …

Functional Studies Of Dcaf14 In Replication Fork Stability And Genome Integrity, Neysha Tirado-Class

USF Tampa Graduate Theses and Dissertations

The response to replication stress is critical for ensuring the stability of replication forks and preserving genome integrity. To aid this response, several factors are recruited to stalled replication forks to prevent irreversible collapse of the replication machinery. Replication fork proteomic analyses of stalled forks reveal enrichment of DCAF14, a component of the Cullin4-RING (CRL4) E3 ubiquitin ligase complex, that mediates replication fork protection by blocking nuclease-mediated digestion of nascent DNA. However, little is known about the molecular mechanism by which DCAF14 functions in the context of replication stress. Notably, loss of function mutations in DCAF14 are associated with a …

Group B Streptococcus Intestinal Barrier Disruption And The Protective Role Of Butyrate, Kristen Dominguez

USF Tampa Graduate Theses and Dissertations

Group B Streptococcus (Streptococcus agalactiae; GBS) is a leading cause of neonatal sepsis worldwide. Intrapartum antibiotics in GBS-colonized mothers significantly reduced the incidence of early-onset sepsis occurring in the first week of life; however, there are currently no prophylactic interventions for late-onset sepsis, occurring within the first 3 months of life. GBS is a pathobiont that primarily colonizes the gastrointestinal tract and can cross the intestinal barrier via both the paracellular and transcellular routes, causing invasive disease. Neonatal susceptibility to GBS intestinal translocation is mediated by inadequate epithelial barrier function and microbiome immaturity; however, the mechanisms by which GBS exploits …

A Homogeneous Time-Resolved Fluorescence Screen To Identify Sirt2 Deacetylase And Defatty-Acylase Inhibitors, Jie Yang, Joel Cassel, Brian C Boyle, Daniel Oppong, Young-Hoon Ahn, Brian P Weiser

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Human sirtuin-2 (SIRT2) has emerged as an attractive drug target for a variety of diseases. The enzyme is a deacylase that can remove chemically different acyl modifications from protein lysine residues. Here, we developed a high-throughput screen based on a homogeneous time-resolved fluorescence (HTRF) binding assay to identify inhibitors of SIRT2's demyristoylase activity, which is uncommon among many ligands that only affect its deacetylase activity. From a test screen of 9600 compounds, we identified a small molecule that inhibited SIRT2's deacetylase activity (IC50 = 7 μM) as well as its demyristoylase activity (IC50 = 37 μM). The inhibitor was composed …

Adipose-Derived Mesenchymal Stem Cells And Their Derived Epidermal Progenitor Cells Conditioned Media Ameliorate Skin Aging In Rats, Mohamed M. Kamal, Omar Ibrahim Badr, Tasnim Mahmoud

Pharmacy

BACKGROUND: Skin alterations are among the most prominent signs of aging, and they arise from both intrinsic and extrinsic factors that interact and mutually influence one another. The use of D-galactose as an aging model in animals has been widely employed in anti-aging research. Adipose tissue-derived mesenchymal stem cells (Ad-MSCs) are particularly promising for skin anti-aging therapy due to their capacity for effective re-epithelization and secretion of various growth factors essential for skin regeneration. Accordingly, we aimed to examine the potential utility of Ad-MSCs as a therapy for skin anti-aging. METHODS: In this study, we isolated and characterized adipose-derived mesenchymal …

Cellular Energy Cycle Mediates An Advection-Like Forward Cell Flow To Support Collective Invasion, Jian Zhang, Jenna Mosier, Yusheng Wu, Logan Waddle, Paul V. Taufelele, Wenjun Wang, Heng Sun, Cynthia A. Reinhart-King

Biomedical Engineering Faculty Publications and Presentations

Collective cell migration is a model for nonequilibrium biological dynamics, which is important for morphogenesis, pattern formation, and cancer metastasis. The current understanding of cellular collective dynamics is based primarily on cells moving within a 2D epithelial monolayer. However, solid tumors often invade surrounding tissues in the form of a stream-like 3D structure, and how biophysical cues are integrated at the cellular level to give rise to this collective streaming remains unclear. Here, it is shown that cell cycle-mediated bioenergetics drive a forward advective flow of cells and energy to the front to support 3D collective invasion. The cell division …

Cornus Officinalis Extract Activates The Keap1/Nrf2 Pathway And Delays T1d Onset In The Nod Mouse, Justin D. Fletcher

USF Tampa Graduate Theses and Dissertations

Type 1 diabetes (T1D) is an autoimmune disorder that results in the destruction of the insulin producing pancreatic β cells. The only therapeutic option following T1D clinical onset is exogenous insulin supplementation. At present, there is no cure for T1D and attempted interventional therapy has been focused on modulating the immune system. Few attempts have been pursued at preserving β cell function and survival. Here we provide a novel approach using extract from the fruit of the Cornus officinalis (CO) tree to preserve β cell function through the prevention of β cell stress. CO has been used in traditional Chinese …

The Role Of Edc3 In Drosophila Melanogaster Neuronal Development, Keelan Zius

Electronic Theses and Dissertations

Enhancer of mRNA-decay 3 (Edc3) is a component of multiple decapping complexes that regulates the transcriptome by targeting a subset of transcripts for decapping for 5’-to-3’ messenger RNA (mRNA) decay. A missense mutation in the conserved Lsm domain of Edc3 has been reported in two siblings presenting with mild, non-syndromic intellectual disability (ID), however, the role of Edc3 is neuronal development has never been evaluated. Here, we use the Drosophila melanogaster model system to investigate the effects of Edc3 disruption on neuronal development. We found Edc3 reduction leads to significant hyperplasia at the larval neuromuscular junction (NMJ), providing the first …

Colocalization Of Odc And Amyloid Plaques In Patients With Alzheimer’S Disease And Down Syndrome, Julia S. Gielczynski

Undergraduate Theses, Capstones, and Recitals

Polyamines, and their rate-limiting enzyme ornithine decarboxylase (ODC), are crucial for many functions in the central nervous system but levels decrease with age. In neurodegenerative diseases, like Alzheimer’s Disease (AD), polyamine levels begin to increase again. Yet, there are still many unanswered questions surrounding polyamine’s possible role in AD, especially in those with Down Syndrome (DS), who also have an extra copy of the amyloid precursor protein (APP) and tend to get AD far earlier than the general population. We aim to investigate if there is colocalization between amyloid plaques and Ornithine Decarboxylase (ODC) in patients with AD and AD/DS, …

Morphological Remodeling Of The Endoplasmic Reticulum During Mitosis And Its Influence On The Integrity Of The Spindle Apparatus, Katie R. Rollins

Electronic Theses and Dissertations

The Endoplasmic Reticulum (ER) is the largest organelle in the cell by surface area and forms contacts with other organelles throughout the cell. In recent work, the ER has been implicated in numerous processes within the cell beyond its canonical roles of protein synthesis and calcium storage. The ER also undergoes a remarkable transition in morphology during cell division, with mitotic divisions requiring a massive remodeling of various membranous organelles such as the nuclear envelope and Golgi. However, whether changes in ER behaviors modulate mitotic events is less clear. The rapid cleavage divisions in the early Drosophila embryo are a …

Effect Of Plumbagin On Chemo-Resistant Metastatic Retinoblastoma, John J. Soto

Theses and Dissertations

Retinoblastoma, which is an ocular malignancy, usually results in poor prognoses in pediatric patients worldwide. Retinoblastoma in some events, can develop metastatic phenotypes which can lead to secondary tumor formation, furthering deleterious patient outcomes. It is of paramount importance to identify and research potent novel compounds that can be used to increase the likelihood of remission. Plumbagin (PLB) is a plant-derived, neuroprotective agent, which exhibits significant anticancer activities during in vitro study. PLB has been shown to have a high therapeutic efficacy against chemoresistant sublines as well as their normal counterparts. We attempted to show that the chemoresistant ABCC1 could …

Frontotemporal Dementia-Like Disease Progression Elicited By Seeded Aggregation And Spread Of Fus, Sonia Vazquez-Sanchez, Britt Tilkin, Fatima Gasset-Rosa, Sitao Zhang, Diana Piol, Melissa Mcalonis-Downes, Jonathan Artates, Noe Govea-Perez, Yana Verresen, Lin Guo, Don Cleveland, James Shorter, Sandrine Da Cruz

Department of Biochemistry and Molecular Biology Faculty Papers

RNA binding proteins have emerged as central players in the mechanisms of many neurodegenerative diseases. In particular, a proteinopathy of fused in sarcoma (FUS) is present in some instances of familial Amyotrophic lateral sclerosis (ALS) and about 10% of sporadic Frontotemporal lobar degeneration (FTLD). Here we establish that focal injection of sonicated human FUS fibrils into brains of mice in which ALS-linked mutant or wild-type human FUS replaces endogenous mouse FUS is sufficient to induce focal cytoplasmic mislocalization and aggregation of mutant and wild-type FUS which with time spreads to distal regions of the brain. Human FUS fibril-induced FUS aggregation …

Macrophage-Driven Car T Cell Resistance In B Cell Lymphoma, Sae Bom Lee

USF Tampa Graduate Theses and Dissertations

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of patients with relapsed/ refractory large B cell lymphoma (LBCL). Despite its promising efficacy, a subset of patients experiences primary resistance or relapse. In Chapter 2, we explore the tumor microenvironment (TME)-induced resistance mechanisms in patients with LBCL. Analysis of the intratumoral immune infiltrates in pre-infusion tumor biopsies revealed that the levels of immunoregulatory macrophages were elevated in patients who responded poorly to axicabtagene ciloleucel (axi-cel). Using preclinical mouse B cell tumor models, we found that the CAR T-cell-produced interferon-gamma (IFN-γ) enhanced the expression of inducible nitric oxide synthase (iNOS, …

Establishment Of Bacteroides In The Gut And Its Role In The Cystic Fibrosis Gut-Lung Axis, Rebecca A. Valls

Dartmouth College Ph.D Dissertations

In the quest to understand the complex interplay between the gut microbiota and cystic fibrosis (CF), a disease characterized by chronic upper respiratory complications and an exacerbated proinflammatory response, our lab engaged in a collaborative study with Dartmouth-Hitchcock Medical Center (DHMC) to characterize the gut microbiota of pediatric CF patients. Initial analyses established a connection between gut microbial composition and respiratory health, particularly highlighting a scarcity of Bacteroides species compared to healthy controls. In following investigations, we utilized random forest models to understand how stool microbiota may influence clinical outcomes of these pediatric CF patients, including: age, upper respiratory infections, …

Discovery Of Oligomeric States And Small Molecules That Affect Deacylase Activities Of Human Sirtuin-2 (Sirt2), Jie Yang

Theses and Dissertations

Human sirtuin isoform 2 (SIRT2) is an NAD+-dependent enzyme that removes various acyl modifications from lysine residues. SIRT2 is involved in many biological processes, such as transcription, DNA repair, cell proliferation, and metabolism. Due to its diverse functions, SIRT2 is implicated in various disease states, including cancers and neurodegenerative disorders. This dissertation aimed to understand the regulation of SIRT2’s deacylase activities and to discover small molecule modulators of SIRT2. In this work, we found that SIRT2 dimerized in solution, and the dimerization decreased the deacetylase activities without affecting the defatty-acylase activity of this protein. Dimerized SIRT2 dissociates into monomers upon …

Tetr Family Regulator, Farr, Influences Rot-Mediated Control Of Virulence Factor Expression In Staphylococcus Aureus, Julia C. Schumacher

USF Tampa Graduate Theses and Dissertations

Point-mutation variants of the TetR family regulator, FarR, have emerged across Staphylococcus aureus sequence types as conferring antibiotic and fatty acid resistance, particularly in Hospital-Associated Methicillin Resistant S. aureus (HA-MRSA) strains. FarR also exhibits an additional largely uncharacterized relationship to virulence factor production, seemingly through the global repressor of toxins—Rot, which functions to regulate S. aureus’ ability to colonize and persist in the host via a complex cascade of signaling. While Rot protein is post-transcriptionally regulated by the highly characterized Agr system, there is little known about its transcriptional regulation. Herein, we explored these dynamics by initially characterizing virulence phenotypes …

Rewiring The Sex-Determination Pathway During The Evolution Of Self-Fertility., Yongquan Shen, Shin-Yi Lin, Jonathan Harbin, Richa Amin, Allison Vassalotti, Joseph Romanowski, Emily Schmidt, Alexis Tierney, Ronald E Ellis

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Although evolution is driven by changes in how regulatory pathways control development, we know little about the molecular details underlying these transitions. The TRA-2 domain that mediates contact with TRA-1 is conserved in Caenorhabditis. By comparing the interaction of these proteins in two species, we identified a striking change in how sexual development is controlled. Identical mutations in this domain promote oogenesis in Caenorhabditis elegans but promote spermatogenesis in Caenorhabditis briggsae. Furthermore, the effects of these mutations involve the male-promoting gene fem-3 in C. elegans but are independent of fem-3 in C. briggsae. Finally, reciprocal mutations in these genes show …

Snpaimer: R Package For Evaluating Ancestry Informative Marker Contributions In Non-Model Population Diagnostics, Kim L. Vertacnik, Oksana V. Vernygora, Julian R. Dupuis

Entomology Faculty Publications

Motivation: Single nucleotide polymorphism (SNP) markers are increasingly popular for population genomics and inferring ancestry for individuals of unknown origin. Because large SNP datasets are impractical for rapid and routine analysis, diagnostics rely on panels of highly informative markers. Strategies exist for selecting these markers, however, resources for efficiently evaluating their performance are limited for non-model systems.

Results: snpAIMeR is a user-friendly R package that evaluates the efficacy of genomic markers for the cluster assignment of unknown individuals. It is intended to help minimize panel size and genotyping effort by determining the informativeness of candidate diagnostic markers. Provided genotype data …

Single-Cell Analysis Identifies Plk1 As A Driver Of Immunosuppressive Tumor Microenvironment In Luad, Yifan Kong, Chaohao Li, Jinpeng Liu, Sai Wu

Markey Cancer Center Faculty Publications

PLK1 (Polo-like kinase 1) plays a critical role in the progression of lung adenocarcinoma (LUAD). Recent studies have unveiled that targeting PLK1 improves the efficacy of immuno- therapy, highlighting its important role in the regulation of tumor immunity. Nevertheless, our understanding of the intricate interplay between PLK1 and the tumor microenvironment (TME) remains incomplete. Here, using genetically engineered mouse model and single- cell RNA-seq analysis, we report that PLK1 promotes an immunosuppressive TME in LUAD, characterized with enhanced M2 polarization of tumor associated macrophages (TAM) and dampened antigen presentation process. Mechanistically, elevated PLK1 coin- cides with increased secretion of CXCL2 …

Neuronal Lrp4 Directs The Development, Maturation And Cytoskeletal Organization Of Drosophila Peripheral Synapses, Alison Depew, Joseph Bruckner, Kate O'Connor-Giles, Timothy Mosca

Student Papers, Posters & Projects

Synaptic development requires multiple signaling pathways to ensure successful connections. Transmembrane receptors are optimally positioned to connect the synapse and the rest of the neuron, often acting as synaptic organizers to synchronize downstream events. One such organizer, the LDL receptor-related protein LRP4, is a cell surface receptor that has been most well-studied postsynaptically at mammalian neuromuscular junctions. Recent work, however, identified emerging roles, but how LRP4 acts as a presynaptic organizer and the downstream mechanisms of LRP4 are not well understood. Here, we show that LRP4 functions presynaptically at Drosophila neuromuscular synapses, acting in motoneurons to instruct pre- and postsynaptic …

Machine-Learning Qsar-Based Novel Drug Identification To Inhibit Retinoblastoma Extracellular Vesicle Release And Metastatic Signaling, Kunhui Huang

Dissertations, Theses, and Capstone Projects

Extracellular vesicles (EVs) are lipid-enclosed particles that are generated by most types of cells and have been identified as an important mechanism for cell communication aside from cell direct contact. EVs contain a variety of functional macromolecules including proteins, lipids, RNA, which can be transferred from the host cells to target cells at a distance. The molecular pathways of EV biogenesis have been studied intensely in recent decades and the process involves several key genes and proteins. Cancer cell released EVs target distant tissues and upregulate signals that are attractive to cancer cell homing, playing a role in tumor progression …

Using Rapid Protein Degradation To Determine The Effect Of Runx1 Loss-Of- Function On Dna Damage Accumulation And Repair., Jackriel Pina Morales

Theses and Dissertations

Germline mutations in RUNX1 are associated with familial platelet disorder with a predisposition to myeloid malignancy (RUNX1-FPDMM), in which patients present with low platelet counts,excessive bleeding and bruising, and an increased risk of Acute Myeloid Leukemia (AML)/Myelodysplastic Syndrome (MDS) development throughout their lifetime. To understand how these loss-of-function mutations in RUNX1 drive predispose to malignancy, it is important to develop a detailed understanding of the molecular basis of RUNX1 function. While RUNX1 is a transcription factor, preliminary data from our group and work from others suggests that RUNX1 also interacts with proteins that are critical for DNA damage …

Novel Role And Mechanisms Of Brd4 In Mediating Mesothelial To Mesenchymal Transition And Pleural Fibrosis, Felix Kankam

Biotechnology Theses

Pleural fibrosis is characterized by myofibroblast accumulation and increased expression of collagen and other extracellular matrices due to injury to the pleura and remodeling. Mesothelial to mesenchymal transition (MesoMT) is an important pathological event that contributes to the pool of myofibroblasts although its regulation remains incompletely understood. Recent research has reported the role of BRD4, a member of the bromodomain extra terminal domain (BET) family, in developing fibrosis in the heart and the lungs. One recent study showed that MEOX1 is a downstream target of BRD4 and mediated cardiac fibroblast activation. Our joint work also demonstrated that NOX4 is implicated …

Maackia Amurensis Seed Lectin (Masl) And Soluble Human Podoplanin (Shpdpn) Sequence Analysis And Effects On Human Oral Squamous Cell Carcinoma (Oscc) Cell Migration And Viability, Ariel C Yin, Cayla J Holdcraft, Eamonn J Brace, Tyler J Hellmig, Sayan Basu, Saumil Parikh, Katarzyna Jachimowska, Evelyne Kalyoussef, Dylan Roden, Soly Baredes, Eugenio M Capitle, David I Suster, Alan J Shienbaum, Caifeng Zhao, Haiyan Zheng, Kevin Balcaen, Simon Devos, Jurgen Haustraete, Mahnaz Fatahzadeh, Gary S Goldberg

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Maackia amurensis lectins serve as research and botanical agents that bind to sialic residues on proteins. For example, M. amurensis seed lectin (MASL) targets the sialic acid modified podoplanin (PDPN) receptor to suppress arthritic chondrocyte inflammation, and inhibit tumor cell growth and motility. However, M. amurensis lectin nomenclature and composition are not clearly defined. Here, we sought to definitively characterize MASL and its effects on tumor cell behavior. We utilized SDS-PAGE and LC-MS/MS to find that M. amurensis lectins can be divided into two groups. MASL is a member of one group which is composed of subunits that form dimers, …

Du Undergraduate Showcase Abstracts: Research, Scholarship, And Creative Works, August Alexander, Kevin Summers, E. Paige Lloyd, Alyssa Aragon, Lauren Wols, Erica Larson, Colton Arciniaga, Lily Baeza, Ellie Barnett-Cashman, Sidney Barbier, Maverick Bartholomew, Ryan Bell, Trevor Briggs, Amanda Brown, Cory Marchi, Maddy Pontius, Jennifer Gallagher, Claire Kwok, Channing Bullock, Alex Mccollister, Kim Gorgens, Daniela Chavez, Yamilet Espinoza Nuñez, Giovanni Valladares Giron, William Christensen, Olivia Kachulis, Daniel Cierasynski, Brandon Cohen, Spenser Dobbs, Lindsay Goolsby, Noah Craver, Nyah Cubbison, Liam Doherty, Nicole Doris, Yan Qin, Alexander Nguyen, Lily Harmon, Shubh Todi, Naichen Zhao, Noah Fagello, Stacia Fritz, Paola Gascot-Chinea, Alex Volkova, Janelyn Geronimo, Elsie Harrington, Shane Simmons, Clarice Hise, Laura Moreno Palmer, Henry Xu, Yesu Leela Pasupula, Emily Fisher, Zachary Hogan, Colin Kleckner, Alyssa Knaus, Erin Kubat, Sam Werkema, Katie Lamberton, Lilliya Larson, Allie Leary, Vanessa Leon-Gamez, James H. Gallagher, E. Dale Broder, Robin M. Tinghitella, Emma Loeber, Alina Mali, Ixchel Marquez, Lauren Mcgrath, Ella Matthews, Grace Naegelen, Audrey Ng, Megan Lucyshyn, Rachel Brough, Alexandra Norman, Joe Ontiveros Rodriguez, Ben Dossett, Ori Miller, Janamejay Sharma, Christopher Reardon, Vincent Pandey, Regan Parish, Ren Pratt, Alisha Pravasi, Sanchari Das, Cari Reichel, Emma Robson, Victoria Rockwell, Jayce Rumsey, Steven Said, Norah Schroder, Alaina Smith, Shannon Murphy, Shujan A. Sharafeldeen, Stanley M. Kanai, James T. Nichols, David E. Clouthier, Macalia R. Augustus, Daniel Silva Rios, Scott Simpson, Anna Sparling, Chase Spurbeck, Kimberly Chiew, Christine Stadnik-Poteroba, Jacqueline Stephenson, Evelyn Stovin, Mia Supan, Lauren Tapper, Will Thrush, Anna Vogt, Michaela Walheim, Jon Weber, Hunter Whitehouse, Kansas Wood, Hayley Sayre, Lydia Mccann, Maread Mclaughlin, Kelly Krumrie, Olivia Wuttke

DU Undergraduate Research Journal Archive

Abstracts from the DU Undergraduate Research Showcase.

Quantitative Proteomic Strategies To Determine Substrate Specificities Of Phosphoprotein Phosphatases, Hieu Trung Nguyen

Dartmouth College Ph.D Dissertations

Reversible phosphorylation is a crucial regulatory mechanism of cellular signaling pathways. Being the most prevalent post-translational modification (PTM) in the cells, with over 75% of all proteins detected to be phosphorylated, phosphorylation regulates a significant number of important cellular processes that have implications in various diseases. Phosphorylation is carried out by protein kinases, which have been extensively studied. However, the opposite reaction, carried out by protein phosphatases, has lagged significantly, exposing a gap of knowledge that is required to be investigated to delineate the kinase-substrate-phosphatase relationship. Phosphoprotein phosphatase family (PPPs), containing seven members of phospho-Serine (pS) and phospho-Threonine (pT) phosphatases, …

Towards A New Role Of Mitochondrial Hydrogen Peroxide In Synaptic Function, Cliyahnelle Z. Alexander

Student Theses and Dissertations

Aerobic metabolism is known to generate damaging ROS, particularly hydrogen peroxide. Reactive oxygen species (ROS) are highly reactive molecules containing oxygen that have the potential to cause damage to cells and tissues in the body. ROS are highly reactive atoms or molecules that rapidly interact with other molecules within a cell. Intracellular accumulation can result in oxidative damage, dysfunction, and cell death. Due to the limitations of H₂O₂ (hydrogen peroxide) detectors, other impacts of ROS exposure may have been missed. HyPer7, a genetically encoded sensor, measures hydrogen peroxide emissions precisely and sensitively, even at sublethal levels, during …

The Effect Of Novel Microtubule Modulators On Experimental Lewy Body Disease, Anuj S. Jamenis

Electronic Theses and Dissertations

In Lewy body disorders, α-synuclein aggregates are believed to destabilize the microtubular framework. However, microtubules are a challenging therapeutic target, as excessive rigidity or flexibility afforded by microtubule modulators may be neurotoxic. Thus, the objective of the present study was to evaluate dual-acting microtubule- stabilizing/destabilizing agents in cellular and animal models of early-stage Lewy body disease.

In Aim 1 we tested the dual-acting tricylic pyrimido[4,5-b]indole analogs AG161-47 and AG161-41 in an in vitro preformed fibril induced model of Lewy body disease. We found that both compounds reduced preformed fibril-seeded α-synucleinopathy without toxicity in primary hippocampal cultures. AG161-47 subtly impacted microtubule …