Medicine and Health Sciences Commons^™

Transcriptional Responses Of Different Brain Cell Types To Oxygen Decline, Camille Ravel-Godreuil, Ethan R Roy, Srinivas N Puttapaka, Sanming Li, Yanyu Wang, Xiaoyi Yuan, Holger K Eltzschig, Wei Cao

Journal Articles

Brain hypoxia is associated with a wide range of physiological and clinical conditions. Although oxygen is an essential constituent of maintaining brain functions, our understanding of how specific brain cell types globally respond and adapt to decreasing oxygen conditions is incomplete. In this study, we exposed mouse primary neurons, astrocytes, and microglia to normoxia and two hypoxic conditions and obtained genome-wide transcriptional profiles of the treated cells. Analysis of differentially expressed genes under conditions of reduced oxygen revealed a canonical hypoxic response shared among different brain cell types. In addition, we observed a higher sensitivity of neurons to oxygen decline, …

Transcriptional Responses Of Different Brain Cell Types To Oxygen Decline, Camille Ravel-Godreuil, Ethan R Roy, Srinivas N Puttapaka, Sanming Li, Yanyu Wang, Xiaoyi Yuan, Holger K Eltzschig, Wei Cao

Journal Articles

Brain hypoxia is associated with a wide range of physiological and clinical conditions. Although oxygen is an essential constituent of maintaining brain functions, our understanding of how specific brain cell types globally respond and adapt to decreasing oxygen conditions is incomplete. In this study, we exposed mouse primary neurons, astrocytes, and microglia to normoxia and two hypoxic conditions and obtained genome-wide transcriptional profiles of the treated cells. Analysis of differentially expressed genes under conditions of reduced oxygen revealed a canonical hypoxic response shared among different brain cell types. In addition, we observed a higher sensitivity of neurons to oxygen decline, …

Rotenone Induces Regionally Distinct Α-Synuclein Protein Aggregation And Activation Of Glia Prior To Loss Of Dopaminergic Neurons In C57bl/6 Mice, Savannah M Rocha, Collin M Bantle, Tawfik Aboellail, Debotri Chatterjee, Richard Jay Smeyne, Ronald B Tjalkens

Department of Neuroscience Faculty Papers

Rotenone is a naturally occurring insecticide that inhibits mitochondrial complex I and leads to neurochemical and neuropathological deficits closely resembling those in Parkinson's disease (PD). Deficits include loss of dopaminergic neurons (DAn) in the substantia nigra pars compacta (SNpc), decreased dopamine levels and aggregation of misfolded alpha-synuclein (p129). In rat models of rotenone-induced parkinsonism, the progression of neuronal injury has been associated with activation of microglia and astrocytes. However, these neuroinflammatory changes have been challenging to study in mice, in part because the systemic rotenone exposure model utilized in rats is more toxic to mice. To establish a reproducible murine …

Response Of Astrocyte Subpopulations Following Spinal Cord Injury, R Vivian Allahyari, Nicolette M Heinsinger, Daniel Hwang, David A Jaffe, Javad Rasouli, Stephanie Shiers, Samantha J Thomas, Theodore J Price, A M Rostami, Angelo C Lepore

Department of Neuroscience Faculty Papers

There is growing appreciation for astrocyte heterogeneity both across and within central nervous system (CNS) regions, as well as between intact and diseased states. Recent work identified multiple astrocyte subpopulations in mature brain. Interestingly, one subpopulation (Population C) was shown to possess significantly enhanced synaptogenic properties in vitro, as compared with other astrocyte subpopulations of adult cortex and spinal cord. Following spinal cord injury (SCI), damaged neurons lose synaptic connections with neuronal partners, resulting in persistent functional loss. We determined whether SCI induces an enhanced synaptomodulatory astrocyte phenotype by shifting toward a greater proportion of Population C cells and/or increasing …

Blood-Brain Barrier: Mechanisms Governing Permeability And Interaction With Peripherally Acting Μ-Opioid Receptor Antagonists., Eugene R. Viscusi, Andrew R Viscusi

Department of Anesthesiology Faculty Papers

The blood-brain barrier (BBB) describes the unique properties of endothelial cells (ECs) that line the central nervous system (CNS) microvasculature. The BBB supports CNS homeostasis via EC-associated transport of ions, nutrients, proteins and waste products between the brain and blood. These transport mechanisms also serve as physiological barriers to pathogens, toxins and xenobiotics to prevent them from contacting neural tissue. The mechanisms that govern BBB permeability pose a challenge to drug design for CNS disorders, including pain, but can be exploited to limit the effects of a drug to the periphery, as in the design of the peripherally acting μ-opioid …

Exosomal Secretion Of A Psychosis-Altered Microrna Regulates Glutamate Receptor Expression; Effects Of Antipsychotics And Maternal Immune Activation, Stephen Amoah

Biomedical Sciences ETDs

MicroRNAs are a subcategory of evolutionarily conserved small non-coding RNAs that are altered in psychiatric conditions. The ability of small secretory microvesicles known as exosomes to influence neuronal and glial function via their microRNA (miRNA) cargo has positioned them as a novel and effective method of cell-to-cell communication. Inflammation, which is evident in schizophrenia (SCZ) and bipolar disorder (BD), and antipsychotics usage may alter miRNA expression in the brain. However, little is known about the role of exosome-secreted miRNAs in the regulation of neuronal gene expression and their relevance for SCZ and BD. Here, we used miRNA profiling and qRT-PCR …

Regulation Of Neuroinflammation After Ischemic Stroke By Astroglial Endothelin Receptor Type-B Signaling, John Mcinnis

Graduate College Dissertations and Theses

A large body of neuroscientific research has focused on reactive gliosis and glial scar formation because these are among the most prominent features of the cellular response to central nervous system (CNS) injury. Despite much progress in our understanding, controversy remains regarding the relative balance between the protective nature of the astroglial scar and its anti-regenerative features. Recent work suggests that astrocytes are heterogeneous in their resting state and in their reactivity. In traumatic injuries such as stroke and spinal cord injury, proliferative reactive astrocytes protect CNS tissue. By contrast, under neuroinflammatory and/or neurodegenerative conditions, neurotoxic astrocyte phenotypes may contribute …

Dna Methylation: A Mechanism For Sustained Alteration Of Kir4.1 Expression Following Central Nervous System Insult, Jessica Boni

All ETDs from UAB

Astrocytes are the most numerous cells in the brain and play a critical role in maintaining homeostatic extracellular potassium ([K+]e). Maintaining low [K+]e is essential for many cellular functions including maintenance of intensely negative resting membrane potentials in the central nervous system. This process is mediated, in part, by a glial-specific, inwardly rectifying potassium channel, Kir4.1. Underscoring the role of Kir4.1 in CNS functioning, genetic mutations in Kcnj10, the gene which encodes Kir4.1, causes seizures, ataxia and developmental disability in humans. Notably, loss of Kir4.1 protein and mRNA are consistently observed after CNS injury, and in a number of neurological …

Circuit-Specific Control Of The Medial Entorhinal Inputs To The Dentate Gyrus By Atypical Presynaptic Nmdars Activated By Astrocytes, Iaroslav Savtchouk, Maria Amalia Di Castro, Rugina Ali, Hiltrud Stubbe, Rafael Lujan, Andrea Volterra

Biomedical Sciences Faculty Research and Publications

Here, we investigated the properties of presynaptic N-methyl-D-aspartate receptors (pre-NMDARs) at corticohippocampal excitatory connections between perforant path (PP) afferents and dentate granule cells (GCs), a circuit involved in memory encoding and centrally affected in Alzheimer’s disease and temporal lobe epilepsy. These receptors were previously reported to increase PP release probability in response to gliotransmitters released from astrocytes. Their activation occurred even under conditions of elevated Mg²⁺ and lack of action potential firing in the axons, although how this could be accomplished was unclear. We now report that these pre-NMDARs contain the GluN3a subunit conferring them low Mg^{2+ …}

Endosomal Trafficking And Exosomal Secretion Of Egfrviii, Kimiya Memarzadeh

Dissertations & Theses (Open Access)

The epidermal growth factor receptor (EGFR) variant three (EGFRvIII) mutation is linked with approximately one third of Glioblastoma Multiforme (GBM) tumors and is associated with poor patient prognosis. Persistent signaling due to a lack of the EGFR ectodomain and inefficient degradation have been suggested to underlie the tumorgenic properties of EGFRvIII. I observed that, like the parental EGFR, EGFRvIII is internalized into the intraluminal vesicles of late endosomes / multivesicular bodies (MVBs) but does not follow the canonical pathway by which wild-type EGFR is degraded following MVB fusion with lysosomes. I determined that EGFRvIII is secreted on exosomes, the intraluminal …

Green Tea Extract, Epigallocatechin Gallate, Protect Against Methamphetamine-Induced Striatal Neurotoxicity In Mice, Allen L. Pan

Dissertations, Theses, and Capstone Projects

Methamphetamine (METH) is a strong psychostimulant and its exposure can lead to serious neurological complications. METH-induced neuronal injury is the result of a complex interplay of different factors including dopamine (DA) overflow, oxidative stress and neuroinflammation. Although the mechanisms of METH-induced neurotoxicity have been extensively studied, there is still no effective therapeutic treatment. Therefore, it is essential to study potential drug candidates that can treat METH-induced neurotoxicity. Green tea extract, epigallocatechin gallate (EGCG), has emerged as a neuroprotective agent that can protect against several neurodegenerative diseases such as Alzheimer’s and Parkinson’s diseases. Recently, our lab has shown that EGCG prevents …

Regional Microglia Are Transcriptionally Distinct But Similarly Exacerbate Neurodegeneration In A Culture Model Of Parkinson's Disease., Eric Wildon Kostuk, Jingli Cai, Lorraine Iacovitti

Department of Neuroscience Faculty Papers

BACKGROUND: Parkinson's disease (PD) is characterized by selective degeneration of dopaminergic (DA) neurons of the substantia nigra pars compacta (SN) while neighboring ventral tegmental area (VTA) DA neurons are relatively spared. Mechanisms underlying the selective protection of the VTA and susceptibility of the SN are still mostly unknown. Here, we demonstrate the importance of balance between astrocytes and microglia in the susceptibility of SN DA neurons to the PD mimetic toxin 1-methyl-4-phenylpyridinium (MPP

METHODS: Previously established methods were used to isolate astrocytes and microglia from the cortex (CTX), SN, and VTA, as well as embryonic midbrain DA neurons from the …

The Role Of Astrocytes In The Development Of Central Chemosensitivity, Kelsey Patterson

All ETDs from UAB

In the two decades since MECP2 was identified as the causative gene in the majority of Rett Syndrome (RTT) cases, transgenic mouse models have played a critical role in our understanding of this X-linked neurodevelopmental disease. However, their exclusive use presents a limitation in translating findings from animal models to the clinic. Here, we characterized growth, anatomical, behavioral, and motor deficits in a novel zinc-finger nuclease murine RTT model from birth through adulthood. Male rats lacking the transcriptional regulatory protein, MeCP2 (Mecp2ZFN/y), are noticeably symptomatic as early as postnatal day (P) 21 and die prematurely, while females lacking one copy …

Regulation Of System Xc-By The Neuropeptide Pacap: Implications For Glutamate Transmission In Drug Addiction, Linghai Kong

Dissertations (1934 -)

Drug addiction is a chronic brain disorder characterized by heightened relapse susceptibility. Drug-induced aberrant glutamate signaling in corticostriatal circuitry contributes to behaviors in virtually every preclinical model of drug seeking and correlates with drug craving in human. Here, we propose that glutamate signaling is a product of integrated activity between neurons and astrocytes, such that disruptions within astrocytes can stem from abnormal neuronal signaling (e.g., altered corticostriatal firing) and be the source of additional disruptions in other neuronal circuits. The astrocytic mechanism studied in these experiments is system xc- (Sxc) since drug-induced changes to this non-vesicular glutamate release mechanism contribute …

Neurovascular Astrocyte Degeneration In The Hyperhomocysteinemia Model Of Vascular Cognitive Impairment And Dementia (Vcid), Tiffany L. Sudduth, Erica M. Weekman, Brittani Rae Price, Jennifer L. Gooch, Abigail E. Woolums, Christopher M. Norris, Donna M. Wilcock

Sanders-Brown Center on Aging Faculty Publications

Vascular cognitive impairment and dementia (VCID) is the second leading cause of dementia behind Alzheimer’s disease (AD) and is a frequent co-morbidity with AD. Despite its prevalence, little is known about the molecular mechanisms underlying the cognitive dysfunction resulting from cerebrovascular disease. Astrocytic end-feet almost completely surround intraparenchymal blood vessels in the brain and express a variety of channels and markers indicative of their specialized functions in the maintenance of ionic and osmotic homeostasis and gliovascular signaling. These functions are mediated by end-foot enrichment of the aquaporin 4 water channel (AQP4), the inward rectifying potassium channel Kir4.1 and the calcium-dependent …

The Role Of Hur In Astrocytes In Spinal Cord Injury, Thaddaeus Kwan

All ETDs from UAB

Neuroinflammation is a defining event during the acute phase of spinal cord injury (SCI). The inflammatory cascade is initiated by activated glial cells such as astrocytes and microglia in the milieu of the injured tissue through release of pro-inflammatory cytokines, matrix metalloproteinases, and reactive oxygen species. These soluble factors produce cytotoxicity to neurons and other cells either directly or indirectly by promoting permeabilization of the blood-spinal cord barrier, edema and subsequent ischemia. These factors also serve to recruit and activate additional glia and peripheral immune cells. The mRNAs of many of these soluble factors such as TNFα, IL-1β, CXCL1, and …

Pituitary Adenylate Cyclase-Activating Polypeptide Orchestrates Neuronal Regulation Of The Astrocytic Glutamate-Releasing Mechanism System XC−, Linghai Kong, Rebecca Albano, Aric Madayag, Nicholas Raddatz, John R. Mantsch, Sujean Choi, Doug Lobner, David A. Baker

Biomedical Sciences Faculty Research and Publications

Glutamate signaling is achieved by an elaborate network involving neurons and astrocytes. Hence, it is critical to better understand how neurons and astrocytes interact to coordinate the cellular regulation of glutamate signaling. In these studies, we used rat cortical cell cultures to examine whether neurons or releasable neuronal factors were capable of regulating system x_c^-(Sxc), a glutamate-releasing mechanism that is expressed primarily by astrocytes and has been shown to regulate synaptic transmission. We found that astrocytes cultured with neurons or exposed to neuronal-conditioned media displayed significantly higher levels of Sxc activity. Next, we demonstrated that the pituitary …

Investigation Of Behavioral And Cellular Changes In The Maternal Immune Activation Model Of Autism Spectrum Disorders, Shreya Roy

Theses & Dissertations

Maternal infection during pregnancy, which leads to maternal immune activation (MIA), is an environmental risk factor for autism spectrum disorders (ASD). MIA can be induced in mice and their offspring exhibit behaviors that model the core symptoms of ASD. One of the core behavioral symptoms in ASD patients is presence of increased repetitive behavior, which is modeled by an increase in marble burying in MIA mice. It has been shown that the deficits seen in MIA mice are associated with the dysregulation of cytokine levels in the developing brain, specifically an increase in pro-inflammatory cytokines. In this thesis, I tested …

Pathological Effects Of Repeated Concussive Tbi In Mouse Models: Periventricular Damage And Ventriculomegaly, Richard H. Wolferz Jr.

Honors Scholar Theses

Repeated concussive traumatic brain injury (rcTBI) is the most prominent form of head injury affecting the brain, with an estimated 1.7 million Americans affected each year (Kuhn 2012). Neurologists have been concerned about the danger of repeated head impacts since the 1920’s, but researchers have only begun to understand the long-term effects of rcTBI (McKee 2009). Although symptoms can be as mild as dizziness, current research suggests that multiple concussions can lead to a progressive degenerative brain disease known as chronic traumatic encephalopathy (CTE) (Luo 2008, McKee 2009, Kane 2013). Research on the brain is just beginning to scratch the …

Sensory Neurons Respond To Neurocan Knock-Down In Reactive Astrocytes, Umang Khandpur

Umang Khandpur, MD Candidate

Pacap And Cocaine Reinstatement: A Neuropeptide Expressed By Corticostriatal Neurons That Regulates Nucleus Accumbens Astrocytes, Linghai Kong, E. Hess, Brian Maunze, Matthew M. Hurley, Khadijah Makky, Sujean Choi, John R. Mantsch, David A. Baker

Biomedical Sciences Faculty Research and Publications

Drug addiction involves heightened relapse vulnerability arising from persistent drug-induced neuro-adaptations, including a) hypofrontality which is thought to reflect reduced firing of cortical afferents to the nucleus accumbens (NAcc) and b) altered glutamate homeostasis in NAcc that likely involves reduced glutamate release and uptake by astrocytes. An important question is whether these forms of pathological plasticity are functionally linked such that reduced corticostriatal firing may result in aberrant regulation of astrocytes in the NAcc. To begin to evaluate this possibility, we first determined whether neurons regulate system xc- (Sxc) activity, a mechanism of non-vesicular glutamate release by astrocytes. We found …

Augmented Cystine–Glutamate Exchange By Pituitary Adenylate Cyclase-Activating Polypeptide Signaling Via The Vpac1 Receptor, Jon M. Resch, Rebecca Albano, Xiaoqian Liu, Julie Hjelmhaug, Doug Lobner, David A. Baker, Sujean Choi

Biomedical Sciences Faculty Research and Publications

In the central nervous system, cystine import in exchange for glutamate through system x_c^- is critical for the production of the antioxidant glutathione by astrocytes, as well as the maintenance of extracellular glutamate. Therefore, regulation of system x_c^- activity affects multiple aspects of cellular physiology and may contribute to disease states. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuronally derived peptide that has already been demonstrated to modulate multiple aspects of glutamate signaling suggesting PACAP may also target activity of cystine–glutamate exchange via system x_c^-. In this study, 24-h treatment of primary cortical …

Mechanisms Of Astrocyte Contribution To Bortezomib-Induced Peripheral Neuropathy, Caleb R. Robinson

Dissertations & Theses (Open Access)

Bortezomib is a proteasome inhibitor used in the treatment of multiple myeloma and other non-solid malignancies, alone or in combination with other chemotherapy drugs. Like other chemotherapeutic agents, bortezomib treatment is frequently accompanied by chemotherapy-induced peripheral neuropathy (CIPN) that may be dose-limiting, adversely affecting quality of life and prognosis. The mechanisms behind bortezomib-induced peripheral neuropathy (BIPN) and CIPN overall are largely unknown. Recent findings in other pain models have indicated substantial involvement of glial cells in chronic pain. Although injury models have shown activation of both astrocytes and microglia following insult, research in other CIPN models has shown astrocytic activation …

Neuroprotective Effects Of Gamma-Glutamylcysteine Ethyl Ester On An In Vivo Moderate Traumatic Brain Injury-Mediated Model And In Vitro In Cortical Astrocytes And Neurons, Jooyoung Cho

Online Theses and Dissertations

Neurodegeneration is the loss of neuronal structures or functions, while neuroprotection is the delay or prevention of neurodegeneration. In traumatic brain injury (TBI), neurodegeneration can occur as the result of oxidative stress, the imbalance of oxidants and antioxidants levels; therefore, antioxidant approaches can be effective therapeutic methods for neuroprotection by attenuating oxidative stress. Glutathione (GSH), a naturally occurring antioxidant, plays an important role in the maintenance of intracellular redox homeostasis by scavenging reactive oxygen species (ROS) and reactive nitrogen species (RNS). In this thesis, we attempted to evaluate the abilities of a GSH precursor, gamma-glutamylcysteine ethyl ester (GCEE), to prevent …

Glial Fibrillary Acidic Protein And Gliosis: Is Gfap More Than A Marker?, Heather Renee Minkel

All ETDs from UAB

Alexander Disease (AxD) is a `gliopathy' caused by toxic, dominant gain-of-function mutations in the gene encoding glial fibrillary acidic protein (GFAP). Two distinct types of AxD exist. Type I AxD affected individuals develop cerebral symptoms by four years of age and generally suffer from macrocephaly, seizures, and physical and mental delays. As detection and diagnosis have improved, a larger portion, now about half of all AxD patients diagnosed, have onset >4 years and brainstem/spinal cord involvement. These type II AxD patients typically experience ataxia, palatal myoclonus, dysphagia and dysphonia. To date no study has examined a mechanistic link between the …

Links Between Insulin Resistance, Lipoprotein Metabolism And Amyloidosis In Alzheimer's Disease, Ian J. Martins, Rhona Creegan

Research outputs 2014 to 2021

The origins of premature brain aging and chronic disease progression are associated with atherogenic diets and sedentary lifestyles in Western communities. Interests in brain aging that involves non alcoholic fatty liver disease (NAFLD), the global stroke epidemic and neurodegeneration have become the focus of nutritional research. Atherogenic diets have been linked to plasma ceramide dysregulation and insulin resistance actively promoting chronic diseases and neurodegeneration in developed countries. Abnormal lipid signaling as observed in chronic diseases such as hypothyroidism, obesity and diabetes is connected to stroke and neurodegenerative diseases in man. Lipids that are involved in calcium and amyloid betahomeostasis are …

Mmp-3 Mediates Psychosine-Induced Globoid Cell Formation: Implications For Leukodystrophy Pathology, Kumiko Ijichi, Graham D. Brown, Craig S. Moore, Paige N. Winokur, Roberto Pagarigan, Stephen J. Crocker

UCHC Articles - Research

Globoid cell leukodystrophy (GLD) or Krabbe disease, is a fatal demyelinating disease attributed to mutations in the galactocerebrosidase (GALC) gene. Loss of function mutations in GALC result in accumulation of the glycolipid intermediate, galactosylsphingosine (psychosine). Due to the cytotoxicity of psychosine, it has been hypothesized that accumulated psychosine underlie the pathophysiology of GLD. However, the cellular mechanisms of GLD pathophysiology remain unclear. Globoid cells, multinucleated microglia/macrophages in the central nervous system (CNS), are a defining characteristic of GLD. Here we report that exposure of primary glial cultures to psychosine induces the expression and the production of matrix metalloproteinase …

Pparg Activation Blocks Development And Reduces Established Neuropathic Pain In Rats, Jenny Morgenweck, Ryan B. Griggs, Renee R. Donahue, James E. Zadina, Bradley K. Taylor

Renee R. Donahue

Peroxisomeproliferator-activated receptor gamma (PPARg) isemerging as a newpharmacotherapeutic target for chronic pain.When oral (3e30 mg/kg/day in chowfor 7 wk) or twice-daily intraperitoneal (1e10 mg/kg/ day for 2 wk) administration began before spared nerve injury (SNI), pioglitazone, a PPARg agonist, dosedependently prevented multiple behavioral signs of somatosensory hypersensitivity. The highest dose of intraperitoneal pioglitazone did not produce ataxia or reductions in transient mechanical and heat nociception, indicating that inhibitory effects on hypersensitivity were not secondary to adverse drug-induced behaviors or antinociception. Inhibitory effects on hypersensitivity persisted at least one week beyond cessation of pioglitazone administration, suggestive of long-lasting effects on gene …

Epigenetic Regulation Of Kir4.1 In Normal And Pathological States: A Focus On Spinal Cord Injury, Sinifunanya Elvee Nwaobi

All ETDs from UAB

Astrocytes are the most numerous cells in the brain and play a critical role in maintaining homeostatic extracellular potassium ([K+]e). This process is mediated, in part, by a glial-specific, inwardly rectifying potassium channel, Kir4.1. Pharmacological inhibition, knock down, or complete knock out of this channel results in astrocytes with increased membrane resistance, depolarized resting membrane potential, and altered extracellular potassium dynamics. Subsequent to the dysregulation of [K+]e, Kir4.1 knockout (KO) animals suffer from ataxia, seizures, and early postnatal death. Interestingly, Kir4.1 has long been characterized as a seizure susceptibility gene. The importance of Kir4.1 is further underscored by recent studies …

Glia And Epilepsy: Excitability And Inflammation, Orrin Devinsky, Annamaria Vezzani, Souhel Najjar, Nihal C. De Lanerolle, Michael A. Rogawski

Michael A. Rogawski

Epilepsy is characterized by recurrent spontaneous seizures due to hyperexcitability and hypersynchrony of brain neurons. Current theories of pathophysiology stress neuronal dysfunction and damage, and aberrant connections as relevant factors. Most antiepileptic drugs target neuronal mechanisms. However, nearly one-third of patients have seizures that are refractory to available medications; a deeper understanding of mechanisms may be required to conceive more effective therapies. Recent studies point to a significant contribution by nonneuronal cells, the glia – especially astrocytes and microglia – in the pathophysiology of epilepsy. This review critically evaluates the role of glia-induced hyperexcitability and inflammation in epilepsy.