Nervous System Diseases Commons^™

Ran Translation At C9orf72-Associated Repeat Expansions Is Selectively Enhanced By The Integrated Stress Response, Katelyn M. Green, M. Rebecca Glineburg, Michael G. Kearse, Brittany N. Flores, Alexander E. Linsalata, Stephen J. Fedak, Aaron C. Goldstrohm, Sami J. Barmada, Peter K. Todd

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Repeat-associated non-AUG (RAN) translation allows for unconventional initiation at disease-causing repeat expansions. As RAN translation contributes to pathogenesis in multiple neurodegenerative disorders, determining its mechanistic underpinnings may inform therapeutic development. Here we analyze RAN translation at G₄C₂ repeat expansions that cause C9orf72-associated amyotrophic lateral sclerosis and frontotemporal dementia (C9RAN) and at CGG repeats that cause fragile X-associated tremor/ataxia syndrome. We find that C9RAN translation initiates through a cap- and eIF4A-dependent mechanism that utilizes a CUG start codon. C9RAN and CGG RAN are both selectively enhanced by integrated stress response (ISR) activation. ISR-enhanced RAN translation requires an …

Structural Insights Into The Potency Of Sk Channel Positive Modulators, Young-Woo Nam, Razan Orfali, Tingting Liu, Kunqian Yu, Meng Cui, Heike Wulff, Miao Zhang

Pharmacy Faculty Articles and Research

Small-conductance Ca2+-activated K+ (SK) channels play essential roles in the regulation of cellular excitability and have been implicated in neurological and cardiovascular diseases through both animal model studies and human genetic association studies. Over the past two decades, positive modulators of SK channels such as NS309 and 1-EBIO have been developed. Our previous structural studies have identified the binding pocket of 1-EBIO and NS309 that is located at the interface between the channel and calmodulin. In this study, we took advantage of four compounds with potencies varying over three orders of magnitude, including 1-EBIO, NS309, SKS-11 (6-bromo-5-methyl-1H-indole-2,3-dione-3-oxime) and …

Simultaneous Uplc–Ms/Ms Analysis Of Two Stable Isotope Labeled Versions Of Sucrose In Mouse Plasma And Brain Samples As Markers Of Blood-Brain Barrier Permeability And Brain Vascular Space, Ekram Ahmed Chowdhury, Saad Alqahtani, Raktima Bhattacharya, Reza Mehvar, Ulrich Bickel

Pharmacy Faculty Articles and Research

Blood Brain Barrier (BBB) permeability is frequently compromised in the course of diseases affecting the central nervous system (CNS). Sucrose is a low molecular weight, hydrophilic marker with low permeability at the naive BBB and therefore one of the widely used indicators of barrier integrity. Our laboratory recently developed a highly sensitive UPLC-MS/MS method for stable isotope labelled [13C12]sucrose in biological matrices. Correction of total brain concentration for contribution of intravascular space is required in such experiments in order to accurately measure BBB permeability, and it is often accomplished by vascular perfusion with buffer solutions prior to brain sampling. The …

Role Of Microglial Amylin Receptors In Mediating Beta Amyloid (Aβ)-Induced Inflammation, Wen Fu, Vlatka Vukojevic, Aarti Patel, Rania Soudy, David Mactavish, David Westaway, Kamaljit Kaur, Valeri Goncharuk, Jack Jhamandas

Pharmacy Faculty Articles and Research

Background: Neuroinflammation in the brain consequent to activation of microglia is viewed as an important component of Alzheimer’s disease (AD) pathology. Amyloid beta (Aβ) protein is known to activate microglia and unleash an inflammatory cascade that eventually results in neuronal dysfunction and death. In this study, we sought to identify the presence of amylin receptors on human fetal and murine microglia and determine whether Aβ activation of the inflammasome complex and subsequent release of cytokines is mediated through these receptors.

Methods: The presence of dimeric components of the amylin receptor (calcitonin receptor and receptor activity modifying protein 3) …

Alzheimer’S Disease: Dawn Of A New Era?, Farideh Amirrad, Emira Bousoik, Kiumars Shamloo, Hassan Al-Shiyab, Viet-Hong Nguyen, Hamidreza Montazeri Aliabadi

Pharmacy Faculty Articles and Research

Alzheimer’s disease (AD) is an irreversible neurodegenerative disease characterized by a progressive decline in cognition and memory, leading to significant impairment in daily activities and ultimately death. It is the most common cause of dementia, the prevalence of which increases with age; however, age is not the only predisposing factor. The pathology of this cognitive impairing disease is still not completely understood, which has limited the development of valid therapeutic options. Recent years have witnessed a wide range of novel approaches to combat this disease, so that they greatly increased our understanding of the disease and of the unique drug …

Effects Of Phosphodiesterase 3a Modulation On Murine Cerebral Microhemorrhages, Rachita K. Sumbria, Vitaly Vasilevko, Mher Mahoney Grigoryan, Annlia Paganini-Hill, Ronald Kim, David H. Cribbs, Mark J. Fisher

Pharmacy Faculty Articles and Research

Background: Cerebral microbleeds (CMB) are MRI-demonstrable cerebral microhemorrhages (CMH) which commonly coexist with ischemic stroke. This creates a challenging therapeutic milieu, and a strategy that simultaneously protects the vessel wall and provides anti-thrombotic activity is an attractive potential approach. Phosphodiesterase 3A (PDE3A) inhibition is known to provide cerebral vessel wall protection combined with anti-thrombotic effects. As an initial step in the development of a therapy that simultaneously treats CMB and ischemic stroke, we hypothesized that inhibition of the PDE3A pathway is protective against CMH development.

Methods: The effect of PDE3A pathway inhibition was studied in the inflammation-induced and …

Tumor Necrosis Factor Α Inhibition For Alzheimer's Disease, Rudy Chang, Kei-Lwun Yee, Rachita K. Sumbria

Pharmacy Faculty Articles and Research

Tumor necrosis factor α (TNF-α) plays a central role in the pathophysiology of Alzheimer’s disease (AD). Food and Drug Administration–approved biologic TNF-α inhibitors are thus a potential treatment for AD, but they do not cross the blood-brain barrier. In this short review, we discuss the involvement of TNF-α in AD, challenges associated with the development of existing biologic TNF-α inhibitors for AD, and potential therapeutic strategies for targeting TNF-α for AD therapy.

Cyclic Ac253, A Novel Amylin Receptor Antagonist, Improves Cognitive Deficits In A Mouse Model Of Alzheimer’S Disease, Rania Soudy, Aarti Patel, Wen Fu, Kamaljit Kaur, David Mactavish, David Westaway, Rachel Davey, Jeffrey Zajac, Jack Jhamandas

Pharmacy Faculty Articles and Research

Introduction: Amylin receptor serves as a portal for the expression of deleterious effects of amyloid b-protein (Ab), a key pathologic hallmark of Alzheimer’s disease. Previously, we showed that AC253, an amylin receptor antagonist, is neuroprotective against Ab toxicity in vitro and abrogates Ab-induced impairment of hippocampal long-term potentiation.

Methods: Amyloid precursor protein–overexpressing TgCRND8 mice received intracerebroventricularly AC253 for 5 months. New cyclized peptide cAC253 was synthesized and administered intraperitoneally three times a week for 10 weeks in the same mouse model. Cognitive functions were monitored, and pathologic changes were quantified biochemically and immunohistochemically.

Results: AC253, when administered …

A Murine Model Of Inflammation-Induced Cerebral Microbleeds, Rachita K. Sumbria, Mher Mahoney Grigoryan, Vitaly Vasilevko, Tatiana B. Krasieva, Miriam Scadeng, Alexandra K. Dvornikova, Annlia Paganini-Hill, Ronald Kim, David H. Cribbs, Mark J. Fisher

Pharmacy Faculty Articles and Research

Background: Cerebral microhemorrhages (CMH) are tiny deposits of blood degradation products in the brain and are pathological substrates of cerebral microbleeds. The existing CMH animal models are β-amyloid-, hypoxic brain injury-, or hypertension-induced. Recent evidence shows that CMH develop independently of hypoxic brain injury, hypertension, or amyloid deposition and CMH are associated with normal aging, sepsis, and neurodegenerative conditions. One common factor among the above pathologies is inflammation, and recent clinical studies show a link between systemic inflammation and CMH. Hence, we hypothesize that inflammation induces CMH development and thus, lipopolysaccharide (LPS)-induced CMH may be an appropriate model to …

Can Gait Signatures Provide Quantitative Measures For Aiding Clinical Decision-Making? A Systematic Meta-Analysis Of Gait Variability Behavior In Patients With Parkinson’S Disease, Niklas König Ignasiak

Physical Therapy Faculty Articles and Research

A disturbed, inconsistent walking pattern is a common feature of patients with Parkinson's disease (PwPD). Such extreme variability in both temporal and spatial parameters of gait has been associated with unstable walking and an elevated prevalence of falls. However, despite their ability to discretise healthy from pathological function, normative variability values for key gait parameters are still missing. Furthermore, an understanding of each parameter's response to pathology, as well as the inter-parameter relationships, has received little attention. The aim of this systematic literature review and meta-analysis was therefore to define threshold levels for pathological gait variability as well as to …

Revealing The Quality Of Movement: A Meta-Analysis Review To Quantify The Thresholds To Pathological Variability During Standing And Walking, Niklas König Ignasiak

Physical Therapy Faculty Articles and Research

Neuromotor processes are inherently noisy, which results in variability during movement and fluctu-ations in motor control. Although controversial, low levels of variability are traditionally considered healthy, while increased levels are thought to be pathological. This systematic review and meta-analysisof the literature investigates the thresholds between healthy and pathological task variability.

After examining 13,195 publications, 109 studies were included. Results from over 3000 healthy sub-jects and 2775 patients revealed an overall positive effect size of pathology on variability of 0.59 forwalking and 0.80 for sway. For the coefficient of variation of stride time (ST) and sway area (SA), upperthresholds of 2.6% …

Connectivity Measures Are Robust Biomarkers Of Cortical Function And Plasticity After Stroke, Jennifer Wu, Erin Burke Quinlan, Lucy Dodakian, Alison Mckenzie, Nikhita Kathuria, Robert J. Zhou, Renee Augsburger, Jill See, Vu H. Lee, Ramesh Srinivasan, Steven C. Cramer

Physical Therapy Faculty Articles and Research

Valid biomarkers of motor system function after stroke could improve clinical decision-making. Electroencephalography-based measures are safe, inexpensive, and accessible in complex medical settings and so are attractive candidates. This study examined specific electroencephalography cortical connectivity measures as biomarkers by assessing their relationship with motor deficits across 28 days of intensive therapy. Resting-state connectivity measures were acquired four times using dense array (256 leads) electroencephalography in 12 hemiparetic patients (7.3 ± 4.0 months post-stroke, age 26–75 years, six male/six female) across 28 days of intensive therapy targeting arm motor deficits. Structural magnetic resonance imaging measured corticospinal tract injury and infarct volume. …

Sma-Causing Missense Mutations In Survival Motor Neuron (Smn) Display A Wide Range Of Phenotypes When Modeled In Drosophila, Kavita Praveen, Ying Wen, Kelsey M. Gray, John J. Noto, Akash R. Patlolla, Gregory D. Van Duyne, A. Gregory Matera

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Mutations in the human survival motor neuron 1 (SMN) gene are the primary cause of spinal muscular atrophy (SMA), a devastating neuromuscular disorder. SMN protein has a well-characterized role in the biogenesis of small nuclear ribonucleoproteins (snRNPs), core components of the spliceosome. Additional tissue-specific and global functions have been ascribed to SMN; however, their relevance to SMA pathology is poorly understood and controversial. Using Drosophila as a model system, we created an allelic series of twelve Smn missense mutations, originally identified in human SMA patients. We show that animals expressing these SMA-causing mutations display a broad range of …

Effects Of Pde4 Pathway Inhibition In Rat Experimental Stroke, Fan Yang, Rachita K. Sumbria, Dong Xue, Chuanhui Yu, Dan He, Shuo Liu, Annlia Paganini-Hill, Mark J. Fisher

Pharmacy Faculty Articles and Research

PURPOSE: The first genomewide association study indicated that variations in the phosphodiesterase 4D (PDE4D) gene confer risk for ischemic stroke. However, inconsistencies among the studies designed to replicate the findings indicated the need for further investigation to elucidate the role of the PDE4 pathway in stroke pathogenesis. Hence, we studied the effect of global inhibition of the PDE4 pathway in two rat experimental stroke models, using the PDE4 inhibitor rolipram. Further, the specific role of the PDE4D isoform in ischemic stroke pathogenesis was studied using PDE4D knockout rats in experimental stroke. METHODS: Rats were subjected to either the …

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, …

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 …

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 …