Medical Biochemistry Commons^™

Differential Transcriptional Alterations In Detoxification Genes In Parkinson’S Disease In Egypt, Nourhan Shebl

Theses and Dissertations

PD is the most common motor neurodegenerative disease worldwide. The underlying cause of PD is still unknow, owingthis to the complexity of the disease. Often, genetics and environmental factors are collaborating in the initiation of the disease. Despite the diversity of its genetical and environmental profiles, the Egyptian population is one of the mostunderrepresented population in terms of PD research. In this study, we investigated PD through various perspectives tohighlight the complexity of the disease in Egypt, taking into consideration the diversity of the Egyptian population. We recruited PD patients and reference controls from 4 governorates: Cairo, Giza, Alexandria, and …

Mistranslating Trnas Alter The Heat Shock Activation By Hsf1, Rebecca Dib

Undergraduate Student Research Internships Conference

Translation, or the production of protein from an mRNA blueprint, is among the most fundamental processes to life as we know it. tRNAs are essential to accurate translation, as they decode the codons of mRNA and recruit corresponding amino acids. Variant tRNAs with anticodon mutations can decrease translational fidelity by recruiting the incorrect amino acid, an aberrant process known as mistranslation. When proteins are produced with incorrect amino acid sequences, they may misfold. The heat shock response functions to alleviate cellular stress caused by misfolded proteins, either by refolding or targeting misfolded proteins for degradation. Hsf1 acts as a transcriptional …

Intrabody-Mediated Postsynaptic Recruitment Of Camkiiα Improves Memory, Anthony Chifor, Jeongyoon Choi Dr., Joongkyu Park Dr.

Medical Student Research Symposium

Long-term potentiation (LTP), the selective strengthening of specific synapses based on recent activity, has widely been accepted as the biological mechanism responsible for learning and memory. N-methyl-D-aspartate receptors (NMDARs) play a critical role in LTP, which when activated, result in a surge of postsynaptic intracellular calcium levels. The calcium rise during LTP results in the activation of Ca²⁺/calmodulin-dependent kinase II alpha (CaMKIIa), which consequently enacts multiple cellular effects that ultimately result in the strengthening of synaptic connections. Previous work has examined the effects of CaMKIIa overexpression in rat hippocampi on spatial memory, however, significant but limited improvement in …

Pre-Clinical Advancements In Biomarkers, Tools, And Therapeutics For A Metabolic Neurodegenerative Disease, Zoë Simmons

Theses and Dissertations--Molecular and Cellular Biochemistry

Glycogen is the storage form of glucose and a highly important substrate for cellular metabolism. Characterization of the enzymes and mechanisms of glycogen metabolism began over 70 years ago and over the last 20 years, a previously unknown protein called laforin has emerged as an important contributor to glycogen metabolism homeostasis. Multiple labs demonstrated that laforin is a glycogen phosphatase and mutations in the gene encoding laforin cause the formation of aberrant glycogen-like aggregates called Lafora bodies (LBs). LBs are cytoplasmic, water-insoluble aggregates that drive neurodegeneration and early death in Lafora disease (LD) patients. The direct relationship between mutated laforin, …

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 …

Thrombospondin Receptor Α2Δ-1 Promotes Synaptogenesis And Spinogenesis Via Postsynaptic Rac1, W. Chris Risher, Namsoo Kim, Sehwon Koh, Ji‑Eun Cho, Petar Mitev, Erin F. Spence, Louis‑Jan Pilaz, Dongqing Wang, Guoping Feng, Debra L. Silver, Scott H. Soderling, Henry H. Yin, Cagla Eroglu

Biomedical Sciences

Astrocytes control excitatory synaptogenesis by secreting thrombospondins (TSPs), which function via their neuronal receptor, the calcium channel subunit α2δ-1. α2δ-1 is a drug target for epilepsy and neuropathic pain; thus the TSP–α2δ-1 interaction is implicated in both synaptic development and disease pathogenesis. However, the mechanism by which this interaction promotes synaptogenesis and the requirement for α2δ-1 for connectivity of the developing mammalian brain are unknown. In this study, we show that global or cell-specific loss of α2δ-1 yields profound deficits in excitatory synapse numbers, ultrastructure, and activity and severely stunts spinogenesis in the mouse cortex. Postsynaptic but not presynaptic α2δ-1 …

Glia-To-Neuron Transfer Of Mirnas Via Extracellular Vesicles: A New Mechanism Underlying Inflammation-Induced Synaptic Alterations, Ilaria Prada, Martina Gabrielli, Elena Turola, Alessia Iorio, Giulia D'Arrigo, Roberta Parolisi, Mariacristina De Luca, Marco Pacifici, Mattia Bastoni, Marta Lombardi, Giuseppe Legname, Dan Cojoc, Annalisa Buffo, Roberto Furlan, Francesca Peruzzi, Claudia Verderio

School of Medicine Faculty Publications

Recent evidence indicates synaptic dysfunction as an early mechanism affected in neuroinflammatory diseases, such as multiple sclerosis, which are characterized by chronic microglia activation. However, the mode(s) of action of reactive microglia in causing synaptic defects are not fully understood. In this study, we show that inflammatory microglia produce extracellular vesicles (EVs) which are enriched in a set of miRNAs that regulate the expression of key synaptic proteins. Among them, miR-146a-5p, a microglia-specific miRNA not present in hippocampal neurons, controls the expression of presynaptic synaptotagmin1 (Syt1) and postsynaptic neuroligin1 (Nlg1), an adhesion protein which play a crucial role in dendritic …

Pitx3null Mutant (Striatal Dopamine-Deficient) Mice Have Exaggerated Spiny Projection Neuron Responses To L-Dopa And D1 Agonism And Lack Baseline Striatonigral Spiking, Ben Sagot

Theses and Dissertations (ETD)

L-3,4 dihidroxyphenylalanine (l-DOPA) strongly stimulates motor activity in parkinsonian patients and animal models of Parkinson's disease. Severe striatal dopamine (DA) loss characterizes Parkinson's disease and its animal models. Given the canonical rate model of Parkinson's Disease pathophysiology based on differences in DA pharmacology manifesting as electrophysiological differences in striatal projection neuron (SPN) spike rates, SPNs should increase spiking during the motor response to l-DOPA. In fact, stimulating specific subsets of these neurons to spike in freely-moving wild type and parkinsonian animals causes or inhibits motor activity as predicted. However, pharmacological effects of DA deficiency, let alone those of DA replacement, …

Novel Targets For Mitochondrial Dysfunction Following Traumatic Brain Injury, Heather M. Yonutas

Theses and Dissertations--Neuroscience

Mitochondrial dysfunction is a phenomenon observed in models of Traumatic Brain Injury (TBI). Loss of mitochondrial bioenergetics can result in diminished cellular homeostasis leading to cellular dysfunction and possible cellular death. Consequently, the resultant tissue damage can manifest as functional deficits and/or disease states. Therapeutic strategies to target this mitochondrial dysfunction have been investigated for models TBI and have shown promising effects.

For this project, we tested the hypothesis that mitoNEET, a novel mitochondrial membrane protein, is a target for pioglitazone mediated neuroprotection. To test this, we used a severe Controlled Cortical Impact (CCI) injury model in mitoNEET null and …

How The Manipulation Of The Ras Homolog Enriched In Striatum Alters The Behavioral And Molecular Progression Of Huntington’S Disease, Franklin A. Lee

University of New Orleans Theses and Dissertations

Huntington’s disease is an incurable, progressive neurological disorder characterized by loss of motor control, psychiatric dysfunction, and eventual dystonia leading to death. Despite the fact that this disorder is caused by a mutation in one single gene, there is no cure. The mutant Huntingtin (mHtt) protein is expressed ubiquitously throughout the brain but frank cell death is limited to the striatum. Recent work has suggested that Rhes, Ras homolog enriched in striatum, which is selectively expressed in the striatum, may play a role in Huntington’s disease neuropathology. In vitro studies have shown Rhes to be an E3 ligase for the …

Steroid Receptor Isoform Expression In Drosophila Nociceptor Neurons Is Required For Normal Dendritic Arbor And Sensitivity, Aidan L. Mcparland, Taylor L. Follansbee, Gwendolyn D. Vesenka, Alexandra E. Panaitiu, Geoffrey K. Ganter

Biology Student Publications

Steroid hormones organize many aspects of development, including that of the nervous system. Steroids also play neuromodulatory and other activational roles, including regulation of sensitivity to painful stimuli in mammals. In Drosophila, ecdysteroids are the only steroid hormones, and therefore the fly represents a simplified model system in which to explore mechanisms of steroid neuromodulation of nociception. In this report, we present evidence that ecdysteroids, acting through two isoforms of their nuclear ecdysone receptor (EcR), modulate sensitivity to noxious thermal and mechanical stimuli in the fly larva. We show that EcRA and EcRB1 are expressed by third instar larvae in …

Antioxidant Gene Therapy Against Neuronal Cell Death, Juliana Navarro-Yepes, Laura Zavala-Flores, Anandhan Annadurai, Fang Wang, Maciej Skotak, Namas Chandra, Ming Li, Aglaia Pappa, Daniel Martinez-Fong, Luz Maria Del Razo, Betzabet Quintanilla-Vega, Rodrigo Franco

Department of Psychology: Faculty Publications

Oxidative stress is a common hallmark of neuronal cell death associated with neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, as well as brain stroke/ischemia and traumatic brain injury. Increased accumulation of reactive species of both oxygen (ROS) and nitrogen (RNS) has been implicated inmitochondrial dysfunction, energy impairment, alterations in metal homeostasis and accumulation of aggregated proteins observed in neurodegenerative disorders, which lead to the activation/modulation of cell death mechanisms that include apoptotic, necrotic and autophagic pathways. Thus, the design of novel antioxidant strategies to selectively target oxidative stress and redox imbalance might represent important therapeutic approaches against neurological disorders. …

Aβ Alters The Dna Methylation Status Of Cell-Fate Genes In An Alzheimer’S Disease Model, Gary D. Isaacs, Noor Taher, Courtney Mckenzie, Rebecca Garrett, Matthew Baker, Nena Fox

Faculty Publications and Presentations

Alzheimer’s disease (AD) is characterized by neurofibrillary tangles and extracellular amyloid-β plaques (Aβ). Despite ongoing research, some ambiguity remains surrounding the role of Aβ in the pathogenesis of this neurodegenerative disease. While several studies have focused on the mutations associated with AD, our understanding of the epigenetic contributions to the disease remains less clear. To that end, we determined the changes in DNA methylation in differentiated human neurons with and without Aβ treatment. We isolated the DNA from neurons treated with Aβ or vehicle, and digested the two samples with either a methylation-sensitive (HpaII) or a methylation-insensitive (MspI) restriction endonuclease. …

Targeting Astrocytes Ameliorates Neurologic Changes In A Mouse Model Of Alzheimer's Disease, Jennifer L. Furman, Diana M. Sama, John C. Gant, Tina L. Beckett, M. Paul Murphy, Adam D. Bachstetter, Linda J. Van Eldik, Christopher M. Norris

Pharmacology and Nutritional Sciences Faculty Publications

Astrocytes are the most abundant cell type in the brain and play a critical role in maintaining healthy nervous tissue. In Alzheimer's disease (AD) and most other neurodegenerative disorders, many astrocytes convert to a chronically "activated" phenotype characterized by morphologic and biochemical changes that appear to compromise protective properties and/or promote harmful neuroinflammatory processes. Activated astrocytes emerge early in the course of AD and become increasingly prominent as clinical and pathological symptoms progress, but few studies have tested the potential of astrocyte-targeted therapeutics in an intact animal model of AD. Here, we used adeno-associated virus (AAV) vectors containing the astrocyte-specific …

The Role Of The Androgen Receptor Cofactor P44/Wdr77 In Astrocyte Activation, Bryce H. Vincent

Dissertations & Theses (Open Access)

Astrogliosis is induced by neuronal damage and is also a pathological feature of the major aging-related neurodegenerative disorders. The mechanisms that control the cascade of astrogliosis have not been well established. In a previous study, we identified a novel androgen receptor (AR)-interacting protein (p44/WDR77) and found that it plays a critical role in the control of proliferation and differentiation of prostate epithelial cells. In the present study, we found that deletion of the p44 gene in the mouse brain caused accelerated aging with dramatic astrogliosis. The p44/WDR77 is expressed in astrocytes and loss of p44/WDR77 expression in astrocytes leads to …

Characterization Of Amino Acid Residues Integral To Neuronal Binding Of Amyloid Beta Protein In Alzheimer’S Disease, Nicole C. Olson

Chemistry and Biochemistry

Purpose: Alzheimer’s Disease is a neurodegenerative disease resulting from over-production and neuronal accumulation of amyloid-beta proteins (Aβ40/Aβ42). The glycine residue at position 33 and histidine residues at positions 13 and 14 are involved with binding and internalization of these proteins, actions potentially inhibited by substituting or sterically hindering these residues with an antibody specific to positions 2-11 (IgG-4.1). Rat pheochromocytoma (PC12) cells differentiated with nerve growth factor were used as a neuronal model to determine whether substitution and/or antibody block amyloid-beta’s neuronal interactions.

Methods: PC12 cells were incubated with fluorescein-labeled-amyloid-beta-40 (F-Aβ40) or substituted F-Aβ40 derivatives (F-Aβ40-H13,14G, F-Aβ40-H13,14G;G33A), with or without …

Mitochondrial Mislocalization Underlies Abeta42-Induced Neuronal Dysfunction In A Drosophila Model Of Alzheimer's Disease., Kanae Iijima-Ando, Stephen A Hearn, Christopher Shenton, Anthony Gatt, Lijuan Zhao, Koichi Iijima

Department of Biochemistry and Molecular Biology Faculty Papers

The amyloid-beta 42 (Abeta42) is thought to play a central role in the pathogenesis of Alzheimer's disease (AD). However, the molecular mechanisms by which Abeta42 induces neuronal dysfunction and degeneration remain elusive. Mitochondrial dysfunctions are implicated in AD brains. Whether mitochondrial dysfunctions are merely a consequence of AD pathology, or are early seminal events in AD pathogenesis remains to be determined. Here, we show that Abeta42 induces mitochondrial mislocalization, which contributes to Abeta42-induced neuronal dysfunction in a transgenic Drosophila model. In the Abeta42 fly brain, mitochondria were reduced in axons and dendrites, and accumulated in the somata without severe mitochondrial …

Abeta42 Mutants With Different Aggregation Profiles Induce Distinct Pathologies In Drosophila., Koichi Iijima, Hsueh-Cheng Chiang, Stephen A Hearn, Inessa Hakker, Anthony Gatt, Christopher Shenton, Linda Granger, Amy Leung, Kanae Iijima-Ando, Yi Zhong

Department of Biochemistry and Molecular Biology Faculty Papers

Aggregation of the amyloid-beta-42 (Abeta42) peptide in the brain parenchyma is a pathological hallmark of Alzheimer's disease (AD), and the prevention of Abeta aggregation has been proposed as a therapeutic intervention in AD. However, recent reports indicate that Abeta can form several different prefibrillar and fibrillar aggregates and that each aggregate may confer different pathogenic effects, suggesting that manipulation of Abeta42 aggregation may not only quantitatively but also qualitatively modify brain pathology. Here, we compare the pathogenicity of human Abeta42 mutants with differing tendencies to aggregate. We examined the aggregation-prone, EOFAD-related Arctic mutation (Abeta42Arc) and an artificial mutation (Abeta42art) that …

Trk: A Neuromodulator Of Age-Specific Behavioral And Neurochemical Responses To Cocaine In Mice., Michelle Niculescu, Shane A Perrine, Jonathan S Miller, Michelle E Ehrlich, Ellen M Unterwald

Farber Institute for Neuroscience Faculty Papers

Responses to psychostimulants vary with age, but the molecular etiologies of these differences are largely unknown. The goal of the present research was to identify age-specific behavioral and molecular adaptations to cocaine and to elucidate the mechanisms involved therein. Postweanling, periadolescent, and adult male CD-1 mice were exposed to cocaine (20 mg/kg) for 7 d. The rewarding effects of cocaine were assessed, as were the response to a Trk antagonist and the regulation of dopamine and cAMP-regulated phosphoprotein, 32 kDa (DARPP-32). Cocaine was rewarding in both periadolescent and adult mice using a conditioned place preference procedure. In contrast, postweanling mice …

Myelin Proteolipid Protein-Specific Cd4+ Cd25+ Regulatory Cells Mediate Genetic Resistance To Experimental Autoimmune Encephalomyelitis, Jay Reddy, Zsolt Illés, Xingmin Zhang, Jeffrey Encinas, Jason Pyrdol, Lindsay Nicholson, Raymond A. Sobel, Kai W. Wucherpfennig, Vijay K. Kuchroo, James P. Allison

Jay Reddy Publications

SJL mice are highly susceptible to experimental autoimmune encephalomyelitis (EAE) induced with myelin proteolipid protein (PLP) peptide 139–151, whereas H-2 congenic B10.S mice are resistant. Immunodominance and susceptibility to EAE are associated with a high precursor frequency of PLP 139–151-specific T cells in the naive repertoire of SJL mice. To understand the mechanism of EAE resistance in B10.S mice, we determined the precursor frequency of PLP 139–151-reactive T cells in both strains by using IA^s/PLP 139–151 tetramers. SJL and B10.S mice had similar frequencies of tetramer-reactive T cells in the naive peripheral repertoire. However, in SJL mice, the …

Modified Amino Acid Copolymers Suppress Myelin Basic Protein 85–99-Induced Encephalomyelitis In Humanized Mice Through Different Effects On T Cells, Zsolt Illés, Joel N.H. Stern, Jay Reddy, Hanspeter Waldner, Marcin P. Mycko, Celia F. Brosnan, Stephan Ellmerich, Daniel M. Altmann, Laura Santambrogio, Jack L. Strominger, Vijay K. Kuchroo

Jay Reddy Publications

A humanized mouse bearing the HLA-DR2 (DRA/DRB1*1501) pro- tein associated with multiple sclerosis (MS) and the myelin basic protein (MBP) 85–99-specific HLA-DR2-restricted T cell receptor from an MS patient has been used to examine the effectiveness of modified amino acid copolymers poly(F,Y,A,K)n and poly- (V,W,A,K)n in therapy of MBP 85–99-induced experimental auto-immune encephalomyelitis (EAE) in comparison to Copolymer 1 [Copaxone, poly(Y,E,A,K)n]. The copolymers were designed to optimize binding to HLA-DR2. Vaccination, prevention, and treatment of MBP-induced EAE in the humanized mice with copolymers FYAK and VWAK ameliorated EAE more effectively than Copolymer 1, reduced the number of pathological lesions, and …

Gtpase-Deficient G Alpha 16 And G Alpha Q Induce Pc12 Cell Differentiation And Persistent Activation Of Cjun Nh2-Terminal Kinases., Lynn E. Heasley, Brooke Storey, Gary R. Fanger, Laura Butterfield, J Zamarripa, D Blumberg, R A. Maue

Dartmouth Scholarship

Persistent stimulation of specific protein kinase pathways has been proposed as a key feature of receptor tyrosine kinases and intracellular oncoproteins that signal neuronal differentiation of rat pheochromocytoma (PC12) cells. Among the protein serine/threonine kinases identified to date, the p42/44 mitogen-activated protein (MAP) kinases have been highlighted for their potential role in signalling PC12 cell differentiation. We report here that retrovirus-mediated expression of GTPase-deficient, constitutively active forms of the heterotrimeric Gq family members, G alpha qQ209L and G alpha 16Q212L, in PC12 cells induces neuronal differentiation as indicated by neurite outgrowth and the increased expression of voltage-dependent sodium channels. Differentiation …