Medical Neurobiology Commons^™

Human Calmodulin Methyltransferase: Expression, Activity On Calmodulin, And Hsp90 Dependence, Sophia Magen, Roberta Magnani, Sitvanit Haziza, Eli Hershkovitz, Robert Houtz, Franca Cambi, Ruti Parvari

Horticulture Faculty Publications

Deletion of the first exon of calmodulin-lysine N-methyltransferase (CaM KMT, previously C2orf34) has been reported in two multigene deletion syndromes, but additional studies on the gene have not been reported. Here we show that in the cells from 2p21 deletion patients the loss of CaM KMT expression results in accumulation of hypomethylated calmodulin compared to normal controls, suggesting that CaM KMT is essential for calmodulin methylation and there are no compensatory mechanisms for CaM methylation in humans. We have further studied the expression of this gene at the transcript and protein levels. We have identified 2 additional …

Pharmacokinetics And Brain Uptake In The Rhesus Monkey Of A Fusion Protein Of Arylsulfatase A And A Monoclonal Antibody Against The Human Insulin Receptor, Ruben J. Boado, Jeff Zhiqiang Lu, Eric Ka-Wai Hui, Rachita K. Sumbria, William M. Pardridge

Pharmacy Faculty Articles and Research

Metachromatic leukodystrophy (MLD) is a lysosomal storage disorder of the brain caused by mutations in the gene encoding the lysosomal sulfatase, arylsulfatase A (ASA). It is not possible to treat the brain in MLD with recombinant ASA, because the enzyme does not cross the blood-brain barrier (BBB). In the present investigation, a BBB-penetrating IgG-ASA fusion protein is engineered and expressed, where the ASA monomer is fused to the carboxyl terminus of each heavy chain of an engineered monoclonal antibody (MAb) against the human insulin receptor (HIR). The HIRMAb crosses the BBB via receptor-mediated transport on the endogenous BBB insulin receptor, …

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 …

Parkinson’S Disease: Molecular Mechanisms And Treatments, Delia Vahey

Senior Honors Theses

Parkinson’s disease is a motor system disorder that is caused primarily by the loss of dopamine-producing brain cells. The most affected brain structure is the pars compacta of the substantia nigra. This area of the brain is essential to the control of voluntary movement, and so its impairment leads to symptoms such as tremors, rigidity, and impaired balance. The neuronal protein alpha-synuclein has been shown to be heavily involved in the pathogenesis of the disease at the cellular level. The currently available treatments for PD mainly target dopamine regulation, and there been no cure developed for the disease at present. …

Active Site Mutations Change The Cleavage Specificity Of Neprilysin., Travis Sexton, Lisa J. Hitchcook, David W. Rodgers, Luke H. Bradley, Louis B. Hersh

Molecular and Cellular Biochemistry Faculty Publications

Neprilysin (NEP), a member of the M13 subgroup of the zinc-dependent endopeptidase family is a membrane bound peptidase capable of cleaving a variety of physiological peptides. We have generated a series of neprilysin variants containing mutations at either one of two active site residues, Phe⁵⁶³ and Ser⁵⁴⁶. Among the mutants studied in detail we observed changes in their activity towards leucine⁵-enkephalin, insulin B chain, and amyloid β_1-40. For example, NEP^F563I displayed an increase in preference towards cleaving leucine⁵-enkephalin relative to insulin B chain, while mutant NEP^S546E was less discriminating …

Ginkgo Extract Egb761 Confers Neuroprotection By Reduction Of Glutamate Release In Ischemic Brain, Alexander Mdzinarishvili, Rachita K. Sumbria, Dorothee Lang, Jochen Klein

Pharmacy Faculty Articles and Research

Purpose - Ginkgo extract EGb761 has shown anti-edema and anti-ischemic effects in various experimental models. In the present study, we demonstrate neuroprotective effects of EGb761 in experimental stroke while monitoring brain metabolism by microdialysis. Methods - We have used oxygen-glucose deprivation in brain slices in vitro and middle cerebral artery occlusion (MCAO) in vivo to induce ischemia in mouse brain. We used microdialysis in mouse striatum to monitor extracellular concentrations of glucose and glutamate. Results - In vitro, EGb761 reduced ischemia-induced cell swelling in hippocampal slices by 60%. In vivo, administration of EGb761 (300 mg/kg) reduced cell degeneration and edema …

Neuroprotective Effects Of Bilobalide Are Accompanied By A Reduction Of Ischemia-Induced Glutamate Release In Vivo, Dorothee Lang, Cornelia Kiewert, Alexander Mdzinarishvili, Tina Maria Schwarzkopf, Rachita K. Sumbria, Joachim Hartmann, Jochen Klein

Pharmacy Faculty Articles and Research

Neuroprotective properties of bilobalide, a specific constituent of Ginkgo extracts, were tested in a mouse model of stroke. After 24 h of middle cerebral artery occlusion (MCAO), bilobalide reduced infarct areas in the core region (striatum) by 40–50% when given at 10 mg/kg 1 h prior to MCAO. Neuroprotection was also observed at lower doses, or when the drug was given 1 h past stroke induction. Sensorimotor function in mice was improved by bilobalide as shown by corner and chimney tests. When brain metabolism in situ was monitored by microdialysis, MCAO caused a rapid disappearance of extracellular glucose in the …

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

Dissertations and 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 …

Unifying The Mathematical Modeling Of In Vivo And In Vitro Microdialysis, Peter M. Bungay, Rachita K. Sumbria, Ulrich Bickel

Pharmacy Faculty Articles and Research

A unifying approach is presented for developing mathematical models of microdialysis that are applicable to both in vitro and in vivo situations. Previous models for cylindrical probes have been limited by accommodating analyte diffusion through the surrounding medium in the radial direction only, i.e., perpendicular to the probe axis, or by incomplete incorporation of diffusion in the axial direction. Both radial and axial diffusion are included in the present work by employing two-dimensional finite element analysis. As in previous models, the nondimensional clearance modulus (Θ) represents the degree to which analyte clearance from the external medium influences diffusion through the …

Orbitofrontal Cortex Provides Cross-Modal Valuation Of Self-Generated Stimuli, William A. Cunningham, Ingrid J. Haas, Ashley S. Waggoner

Department of Political Science: Faculty Publications

Prior research has shown that the orbitofrontal cortex (OFC) plays an important role in the representation of the evaluation of stimuli, regardless of stimulus modality. Based on these findings, researchers have proposed that the OFC serves a common currency function, allowing for the direct comparison of different types of perceptual stimuli (e.g. food, drink, money). The present study was designed to extend this research and investigate whether these same regions of OFC that have been identified in previous research are involved in evaluating imagined stimuli. Specifically, we asked participants to draw on prior attitudinal knowledge to generate internal representations of …

Substrate And Regulation Of Mitochondrial Μ-Calpain, Aashish Joshi

University of Kentucky Doctoral Dissertations

μ -Calpain is localized to the mitochondrial intermembrane space. Apoptosisinducing factor (AIF), which executes caspase-independent cell death, is also localized to the mitochondrial intermembrane space. Following processing at the N-terminus, AIF becomes truncated (tAIF) and is released from mitochondria. The protease responsible for AIF processing has not been established. The same submitochondrial localization of mitochondrial μ-calpain and AIF gives support to the hypothesis that mitochondrial μ-calpain may be responsible for processing AIF. Atractyloside-induced tAIF release in rat liver mitochondria was inhibited by cysteine protease inhibitor MDL28170, but not by calpain inhibitors PD150606 or calpastatin. Moreover, μ-calpain immunoreactivity was difficult to …

Neuroendocrine Peptides Neuropeptide-Y (Npy) And Peptide-Yy (Pyy) Suppress Cl- Secretion And K+ Secretion In Guinea Pig Distal Colon Through Action At Y2-Receptors, Susan T. Halm, Jin Zhang, Dan R. Halm

Neuroscience, Cell Biology & Physiology Faculty Publications

Electrogenic Cl^– and K⁺ secretion in isolated mucosa from guinea pig distal colon measured as short-circuit current (I_sc) and transepithelial conductance (G_t) were stimulated by epinephrine (epi), prostaglandin-E₂ (PGE₂) and carbachol (CCh). neuropeptide-Y (NPY) and peptide-YY (PYY) inhibited by 60% Cl^– secretion activated by either PGE₂ or PGE₂+CCh with EC₅₀’s of 16nM and 6nM, respectively. Neither peptide markedly inhibited the transient component of the PGE₂+CCh response. Immunoreactivity (IR) for NPY was present in enteric ganglia and in proximity with crypts. Basolateral membranes of …

Viral Vectors In The Research Laboratory: Just How Safe Are They?, Dawn P. Wooley, Kimberly Kay Morris, Robert Mcrae, John C. Trefry

Neuroscience, Cell Biology & Physiology Faculty Publications

No abstract provided.

Iron Dysregulation And Inflammation In Alzheimer’S Disease, Shino D. Magaki

Loma Linda University Electronic Theses, Dissertations & Projects

Alzheimer’s disease (AD) is the most common form of senile dementia in the US and worldwide but the causes of its pathogenesis are currently unknown. In this study, we examined two processes that have been implicated in the early stages of AD and other forms of neurodegeneration, iron dysregulation and inflammation, both of which can promote the increased production of amyloid precursor protein (APP). We have measured different pools of brain iron in transgenic iron regulatory protein 2 knockout (IRP2-/-) mice in the early stages of neurodegeneration and in affected brain regions from AD patients at different stages of the …

Unlv Magazine, Cate Weeks, Shane Bevell, Erin O'Donnell, Eric Leake, Lori Bachand, David G. Schwartz, David Ashley

UNLV Magazine

No abstract provided.

Mechanisms Of Hbo-Induced Neuroprotection In A Neonatal Hypoxia-Ischemia Model, John Winter Calvert

Loma Linda University Electronic Theses, Dissertations & Projects

With an incidence approaching 1/4000 live births and as high as 60% in low birth weight infants, cerebral hypoxia-ischemia during the perinatal period is the single most important cause of acute mortality and chronic disability in newborns. Herein, we tested the hypothesis that following a hypoxic-ischemic insult hyperbaric oxygen (HBO) treatment can restore high energy metabolite levels in the affected regions of the brain and through this increase in energy levels ameliorate the spread of cell death following the insult. We also investigated if an additional mechanism by which HBO affords its neuroprotection is by altering the expression of the …

Neuromotor And Cognitive Development In Children With Cerebral Palsy In Relation To Neural Plasticity, Vaniecea Pollard

McCabe Thesis Collection

Infants with neurological disabilities, such as cerebral palsy (CP) and Down syndrome (DS), show severe delays in motor and cognitive development relative to chronological age. Involvement of neural plasticity as a treatment of such neurological disorders is increasingly being seen. Previous studies have found that interventions involving sensory linked motor performance have been critical in facilitating motor improvement. The purpose of this study was to compare self-initiated mobility in children with CP and DS. Three infants, ages 8, 9, and 22 months, with diagnoses of no CP, DS, and CP respectively, participated in the study. The infants were videotaped in …

Prolonged Cyclooxygenase-2 Induction In Neurons And Glia Following Traumatic Brain Injury In The Rat, Kenneth I. Strauss, Mary F. Barbe, Renee Marshall Demarest, Ramesh Raghupathi, Samir Mehta, Raj K. Narayan

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Cyclooxygenase-2 (COX2) is a primary inflammatory mediator that converts arachidonic acid into precursors of vasoactive prostaglandins, producing reactive oxygen species in the process. Under normal conditions COX2 is not detectable, except at low abundance in the brain. This study demonstrates a distinctive pattern of COX2 increases in the brain over time following traumatic brain injury (TBI). Quantitative lysate ribonuclease protection assays indicate acute and sustained increases in COX2 mRNA in two rat models of TBI. In the lateral fluid percussion model, COX2 mRNA is significantly elevated (>twofold, p < 0.05, Dunnett) at 1 day postinjury in the injured cortex and bilaterally in the hippocampus, compared to sham-injured controls. In the lateral cortical impact model (LCI), COX2 mRNA peaks around 6 h postinjury in the ipsilateral cerebral cortex (fivefold induction, p < 0.05, Dunnett) and in the ipsilateral and contralateral hippocampus (two- and six-fold induction, respectively, p < 0.05, Dunnett). Increases are sustained out to 3 days postinjury in the injured cortex in both models. Further analyses use the LCI model to evaluate COX2 induction. Immunoblot analyses confirm increased levels of COX2 protein in the cortex and hippocampus. Profound increases in COX2 protein are observed in the cortex at 1-3 days, that return to sham levels by 7 days postinjury (p < 0.05, Dunnett). The cellular pattern of COX2 induction following TBI has been characterized using immunohistochemistry. COX2-immunoreactivity (-ir) rises acutely (cell numbers and intensity) and remains elevated for several days following TBI. Increases in COX2-ir colocalize with neurons (MAP2-ir) and glia (GFAP-ir). Increases in COX2-ir are observed in cerebral cortex and hippocampus, ipsilateral and contralateral to injury as early as 2 h postinjury. Neurons in the ipsilateral parietal, perirhinal and piriform cortex become intensely COX2-ir from 2 h to at least 3 days postinjury. In agreement with the mRNA and immunoblot results, COX2-ir appears greatest in the contralateral hippocampus. Hippocampal COX2-ir progresses from the pyramidal cell layer of the CA1 and CA2 region at 2 h, to the CA3 pyramidal cells and dentate polymorphic and granule cell layers by 24 h postinjury. These increases are distinct from those observed following inflammatory challenge, and correspond to brain areas previously identified with the neurological and cognitive deficits associated with TBI. While COX2 induction following TBI may result in selective beneficial responses, chronic COX2 production may contribute to free radical mediated cellular damage, vascular dysfunction, and alterations in cellular metabolism. These may cause secondary injuries to the brain that promote neuropathology and worsen behavioral outcome.

Direct Demonstration Of Retroviral Recombination In A Rhesus Monkey, Dawn P. Wooley, Randall A. Smith, Susan Czajak, Ronald C. Desrosiers

Neuroscience, Cell Biology & Physiology Faculty Publications

Recombination may be an important mechanism for increasing variation in retroviral populations. Retroviral recombination has been demonstrated in tissue culture systems by artificially creating doubly infected cells. Evidence for retroviral recombination in vivo is indirect and is based principally on the identification of apparently mosaic human immunodeficiency virus type 1 genomes from phylogenetic analyses of viral sequences. We infected a rhesus monkey with two different molecularly cloned strains of simian immunodeficiency virus. One strain of virus had a deletion in vpx and vpr, and the other strain had a deletion in nef. Each strain on its own induced low virus …

Effects Of Natural Sequence Variation On Recognition By Monoclonal Antibodies Neutralize Simian Immunodeficiency Virus Infectivity, Weon Sang Choi, Catherine Collignon, Clotilde Thiriart, Dawn P. Wooley, E. J. Scott, Karen A. Kent, Ronald C. Desrosiers

Neuroscience, Cell Biology & Physiology Faculty Publications

The determinants of immune recognition by five monoclonal antibodies (KK5, KK9, KK17, Senv7.1, and Senv101.1) that neutralize simian immunodeficiency virus infectivity were analyzed. These five neutralizing monoclonal antibodies were generated to native SIVmac251 envelope glycoprotein expressed by a vaccinia virus recombinant vector. All five recognize conformational or discontinuous epitopes and require native antigen for optimal recognition. These monoclonal antibodies also recognize SIVmac239 gp120, but they do not recognize gp120 of two natural variants of SIVmac239, 1-12 and 8-22, which evolved during the course of persistent infection in vivo (D.P.W. Burns and R.C. Desrosiers, J. Virol. 65:1843-1854, 1991). Recombinant viruses which …

High Rates Of Frameshift Mutations Within Homo-Oligomeric Runs During A Single Cycle Of Retroviral Replication, Dawn P. Wooley, H. M. Temin

Neuroscience, Cell Biology & Physiology Faculty Publications

Homo-oligomeric runs were inserted into a spleen necrosis virus-based retrovirus vector to determine the nature and rate of mutations within runs of 10 to 12 identical nucleotides during a single replication cycle. Clones of helper cells containing integrated copies of retroviral vectors were used to produce virus for infection of target (nonhelper) cells. Proviral sequences from target cell clones were compared with proviral sequences from helper cell clones to study mutations that occurred during a single cycle of replication. In addition to the internal region spanning the homo-oligomeric inserts, a naturally occurring run of 10 T's in the long terminal …

Simian Immunodeficiency Virus Mutants Resistant To Serum Neutralization Arise During Persistent Infection Of Rhesus Monkeys, Dawn P. Wooley, Catherine Collignon, Ronald C. Desrosiers

Neuroscience, Cell Biology & Physiology Faculty Publications

We previously described the pattern of sequence variation in gp120 following persistent infection of rhesus monkeys with the pathogenic simian immunodeficiency virus SIVmac239 molecular clone (D.P.W. Burns and R.C. Desrosiers, J. Virol. 65:1843, 1991). Sequence changes were confined largely to five variable regions (V1 to V5), four of which correspond to human immunodeficiency virus type 1 (HIV-1) gp120 variable regions. Remarkably, 182 of 186 nucleotide substitutions that were documented in these variable regions resulted in amino acid changes. This is an extremely nonrandom pattern, which suggests selective pressure driving amino acid changes in discrete variable domains. In the present study, …

Strain-Specific Neutralizing Determinant In The Transmembrane Protein Of Simian Immunodeficiency Virus, Toshiaki Kodama, Dawn P. Wooley, Daniel P. Silva, Fulvia Dimarzo Veronese, Ronald C. Desrosiers

Neuroscience, Cell Biology & Physiology Faculty Publications

Monoclonal antibody SF8/5E11, which recognizes the transmembrane protein (TMP) of simian immunodeficiency virus of macaque monkeys (SIVmac), displayed strict strain specificity. It reacted with cloned and uncloned SIVmac251 but not with cloned SIVmac142 and SIVmac239 on immunoblots. This monoclonal antibody neutralized infection by cloned, cell-free SIVmac251 and inhibited formation of syncytia by cloned SIVmac251-infected cells; these activities were specific to cloned SIVmac251 and did not occur with the other viruses. Site-specific mutagenesis was used to show that TMP amino acids 106 to 110 (Asp-Trp-Asn-Asn-Asp) determined the strain specificity of the monoclonal antibody. This strain-specific neutralizing determinant is located within a …

Selection Of Genetic Variants Of Simian Immunodeficiency Virus In Persistently Infected Rhesus Monkeys, Dawn P. Wooley, Ronald C. Desrosiers

Neuroscience, Cell Biology & Physiology Faculty Publications

Genetic and antigenic variation may be one means by which lentiviruses that cause AIDS avoid elimination by host immune responses. Genetic variation in the envelope gene (env) was studied by comparing the nucleotide sequences of 27 clones obtained from two rhesus monkeys infected with molecularly cloned simian immunodeficiency virus. All 27 clones differed from each other and differed from the input clone in the gp120 (SU) portion of the envelope gene. Nucleotide substitutions were shown to accumulate with time at an average rate of 8.5 per 1,000 per year in SU. Surprisingly, the majority of nucleotide substitutions (81%) resulted in …

Significance Of Premature Stop Codons In Env Of Simian Immunodeficiency Virus, Toshiaki Kodama, Dawn P. Wooley, Yathirajulu M. Naidu, Harry W. Kestler Iii, Muthiah D. Daniel, Yen Li, Ronald C. Desrosiers

Neuroscience, Cell Biology & Physiology Faculty Publications

The location of the translational termination codon for the transmembrane protein (TMP) varies in three infectious molecular clones of simian immunodeficiency virus from macaques (SIV_mac). The SIV_mac251 and SIV_mac142 infectious clones have premature stop signals that differ in location by one codon; transfection of these DNAs into human HUT-78 cells yielded virus with a truncated TMP (28 to 30 kilodaltons [kDa]). The SIV_mac239 infectious clone does not have a premature stop codon in its TMP-coding region. Transfection of HUT-78 cells with this clone initially yielded virus with a full-length TMP (41 kDa). …

Hyperosmotic Modification Of Brain Extracellular Space And Blood-Brain Barrier In The Rat As Observed By Electron Microscopy, Susan A. Meacham

Loma Linda University Electronic Theses, Dissertations & Projects

The highly selective permeability of cerebral blood vessels, termed the blood-brain barrier, is due to endothelial tight junctions (zonulae occludentes). Hyperosmotic solutions reversibly open the blood-brain barrier. The purpose of this study is to determine the immediate effect of hyperosmotic arabinose perfusion upon the cerebrovascular endothelium, the morphology of the cerebral cortex, and the cortical extracellular space.

Twelve adult male Sprague-Dawley rats were separated into three groups of four animals each: control, intermediate, and extreme. Controls were perfused with a Tyrode's solution prewash followed by trialdehyde fixative. The intermediate group received a prewash of 740 mmol/kg arabinose followed by the …

A Semiquantitative Analysis Of The Chorda Tympani Taste Pathway In The Rat Brain With The 2-Deoxyglucose Method, Charles L. Hardison

Loma Linda University Electronic Theses, Dissertations & Projects

This thesis is based on a semiquantitative analysis of four nuclear relay centers [nucleus tractus solitarius (NTS), parabrachial nucleus (PBN), ventroposteromedial nucleus (VPM), gustatory neocortex (GNC)] in the chorda tympani nerve pathway. Metabolic changes were examined by the 2-deoxyglucose method in which one chorda tympani nerve was chemically stimulated and its contralateral side lesioned. Coronal sections of four taste centers were prepared for autoradiography and Nissl staining. Densities of the autoradiograms were determined by means of a video based image processor. Relative differences in the optical density ratios of the stimulated versus lesioned nuclear grey matter areas to white matter …

A Study Of Regeneration Of Peripheral Nerve In The Rat, James C. Jay

Loma Linda University Electronic Theses, Dissertations & Projects

Due to improvements in fixation and embedding techniques a restudy of regenerating peripheral nerve was thought advisable in order to better understand and describe the processes which take place.

Femoral nerves of white Wistar rats were used. The lesions were made by either crushing or severing the nerve. After a period of regeneration, varying from 12 hours to six days, the wound was reopened and the injured portion fixed in situ with 1% osmium tetroxide. The tissues were then removed, dehydrated, embedded and sectioned. The sections were stained and studied with a modified RCA EMU2A electron microscope.

Observations revealed that …

Cerebral Anoxia And Its Residuals: Pt. Iii. The Structural Changes, Cyril B. Courville

Medical Arts and Sciences: A Scientific Journal of the College of Medical Evangelists

No abstract provided.