1
|
van Noorden CJ, Yetkin-Arik B, Serrano Martinez P, Bakker N, van Breest Smallenburg ME, Schlingemann RO, Klaassen I, Majc B, Habic A, Bogataj U, Galun SK, Vittori M, Erdani Kreft M, Novak M, Breznik B, Hira VV. New Insights in ATP Synthesis as Therapeutic Target in Cancer and Angiogenic Ocular Diseases. J Histochem Cytochem 2024; 72:329-352. [PMID: 38733294 PMCID: PMC11107438 DOI: 10.1369/00221554241249515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 04/01/2024] [Indexed: 05/13/2024] Open
Abstract
Lactate and ATP formation by aerobic glycolysis, the Warburg effect, is considered a hallmark of cancer. During angiogenesis in non-cancerous tissue, proliferating stalk endothelial cells (ECs) also produce lactate and ATP by aerobic glycolysis. In fact, all proliferating cells, both non-cancer and cancer cells, need lactate for the biosynthesis of building blocks for cell growth and tissue expansion. Moreover, both non-proliferating cancer stem cells in tumors and leader tip ECs during angiogenesis rely on glycolysis for pyruvate production, which is used for ATP synthesis in mitochondria through oxidative phosphorylation (OXPHOS). Therefore, aerobic glycolysis is not a specific hallmark of cancer but rather a hallmark of proliferating cells and limits its utility in cancer therapy. However, local treatment of angiogenic eye conditions with inhibitors of glycolysis may be a safe therapeutic option that warrants experimental investigation. Most types of cells in the eye such as photoreceptors and pericytes use OXPHOS for ATP production, whereas proliferating angiogenic stalk ECs rely on glycolysis for lactate and ATP production. (J Histochem Cytochem XX.XXX-XXX, XXXX).
Collapse
Affiliation(s)
- Cornelis J.F. van Noorden
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia
- Ocular Angiogenesis Group, Amsterdam University Medical Center Location University of Amsterdam, Amsterdam, The Netherlands
| | - Bahar Yetkin-Arik
- Department of Pediatric Pulmonology, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
- Regenerative Medicine Center Utrecht, University Medical Center Utrecht, Utrecht, The Netherlands
- Centre for Living Technologies, Alliance TU/e, WUR, UU, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Paola Serrano Martinez
- Ocular Angiogenesis Group, Amsterdam University Medical Center Location University of Amsterdam, Amsterdam, The Netherlands
| | - Noëlle Bakker
- Ocular Angiogenesis Group, Amsterdam University Medical Center Location University of Amsterdam, Amsterdam, The Netherlands
| | | | - Reinier O. Schlingemann
- Ocular Angiogenesis Group, Amsterdam University Medical Center Location University of Amsterdam, Amsterdam, The Netherlands
- Department of Ophthalmology, Amsterdam University Medical Center Location University of Amsterdam, Amsterdam, The Netherlands
- Department of Ophthalmology, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, University of Lausanne, Lausanne, Switzerland
| | - Ingeborg Klaassen
- Ocular Angiogenesis Group, Amsterdam University Medical Center Location University of Amsterdam, Amsterdam, The Netherlands
| | - Bernarda Majc
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia
| | - Anamarija Habic
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia
- Jozef Stefan Postgraduate School, Ljubljana, Slovenia
| | - Urban Bogataj
- Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - S. Katrin Galun
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia
| | - Milos Vittori
- Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Mateja Erdani Kreft
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Metka Novak
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia
| | - Barbara Breznik
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia
| | - Vashendriya V.V. Hira
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia
| |
Collapse
|
2
|
Sočan V, Dolinar K, Kržan M. Transporters involved in adult rat cortical astrocyte dopamine uptake: Kinetics, expression and pharmacological modulation. Eur J Neurosci 2024; 59:1296-1310. [PMID: 38054361 DOI: 10.1111/ejn.16202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/03/2023] [Accepted: 11/10/2023] [Indexed: 12/07/2023]
Abstract
Astrocytes, glial cells in the central nervous system, perform a multitude of homeostatic functions and are in constant bidirectional communication with neuronal cells, a concept named the tripartite synapse; however, their role in the dopamine homeostasis remains unexplored. The aim of this study was to clarify the pharmacological and molecular characteristics of dopamine transport in cultured cortical astrocytes of adult rats. In addition, we were interested in the expression of mRNA of dopamine transporters as well as dopamine receptors D1 and D2 and in the effect of dopaminergic drugs on the expression of these transporters and receptors. We have found that astrocytes possess both Na+-dependent and Na+-independent transporters. Uptake of radiolabelled dopamine was time-, temperature- and concentration-dependent and was inhibited by decynium-22, a plasma membrane monoamine transporter inhibitor, tricyclic antidepressants desipramine and nortriptyline, both inhibitors of the norepinephrine transporter. Results of transporter mRNA expression indicate that the main transporters involved in cortical astrocyte dopamine uptake are the norepinephrine transporter and plasma membrane monoamine transporter. Both dopamine receptor subtypes were identified in cortical astrocyte cultures. Twenty-four-hour treatment of astrocyte cultures with apomorphine, a D1/D2 agonist, induced upregulation of D1 receptor, norepinephrine transporter and plasma membrane monoamine transporter, whereas the latter was downregulated by haloperidol and L-DOPA. Astrocytes take up dopamine by multiple transporters and express dopamine receptors, which are sensitive to dopaminergic drugs. The findings of this study could open a promising area of research for the fine-tuning of existing therapeutic strategies.
Collapse
Affiliation(s)
- Vesna Sočan
- Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Klemen Dolinar
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Mojca Kržan
- Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| |
Collapse
|
3
|
Jaraíz-Rodríguez M, Del Prado L, Balsa E. Metabolic remodeling in astrocytes: Paving the path to brain tumor development. Neurobiol Dis 2023; 188:106327. [PMID: 37839712 DOI: 10.1016/j.nbd.2023.106327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 10/11/2023] [Accepted: 10/12/2023] [Indexed: 10/17/2023] Open
Abstract
The brain is a highly metabolic organ, composed of multiple cell classes, that controls crucial functions of the body. Although neurons have traditionally been the main protagonist, astrocytes have gained significant attention over the last decade. In this regard, astrocytes are a type of glial cells that have recently emerged as critical regulators of central nervous system (CNS) function and play a significant role in maintaining brain energy metabolism. However, in certain scenarios, astrocyte behavior can go awry, which poses a significant threat to brain integrity and function. This is definitively the case for mutations that turn normal astrocytes and astrocytic precursors into gliomas, an aggressive type of brain tumor. In addition, healthy astrocytes can interact with tumor cells, becoming part of the tumor microenvironment and influencing disease progression. In this review, we discuss the recent evidence suggesting that disturbed metabolism in astrocytes can contribute to the development and progression of fatal human diseases such as cancer. Emphasis is placed on detailing the molecular bases and metabolic pathways of this disease and highlighting unique metabolic vulnerabilities that can potentially be exploited to develop successful therapeutic opportunities.
Collapse
Affiliation(s)
- Myriam Jaraíz-Rodríguez
- Centro de Biología Molecular Severo Ochoa (CBMSO), Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
| | - Lucia Del Prado
- Centro de Biología Molecular Severo Ochoa (CBMSO), Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
| | - Eduardo Balsa
- Centro de Biología Molecular Severo Ochoa (CBMSO), Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain; Instituto Universitario de Biología Molecular - IUBM (Universidad Autónoma de Madrid), Madrid, Spain.
| |
Collapse
|
4
|
Potokar M, Zorec R, Jorgačevski J. Astrocytes Are a Key Target for Neurotropic Viral Infection. Cells 2023; 12:2307. [PMID: 37759529 PMCID: PMC10528686 DOI: 10.3390/cells12182307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 08/28/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
Astrocytes are increasingly recognized as important viral host cells in the central nervous system. These cells can produce relatively high quantities of new virions. In part, this can be attributed to the characteristics of astrocyte metabolism and its abundant and dynamic cytoskeleton network. Astrocytes are anatomically localized adjacent to interfaces between blood capillaries and brain parenchyma and between blood capillaries and brain ventricles. Moreover, astrocytes exhibit a larger membrane interface with the extracellular space than neurons. These properties, together with the expression of various and numerous viral entry receptors, a relatively high rate of endocytosis, and morphological plasticity of intracellular organelles, render astrocytes important target cells in neurotropic infections. In this review, we describe factors that mediate the high susceptibility of astrocytes to viral infection and replication, including the anatomic localization of astrocytes, morphology, expression of viral entry receptors, and various forms of autophagy.
Collapse
Affiliation(s)
- Maja Potokar
- Laboratory of Neuroendocrinology–Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
- Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology–Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
- Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia
| | - Jernej Jorgačevski
- Laboratory of Neuroendocrinology–Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
- Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia
| |
Collapse
|
5
|
Fleeman RM, Kuhn MK, Chan DC, Proctor EA. Apolipoprotein E ε4 modulates astrocyte neuronal support functions in the presence of amyloid-β. J Neurochem 2023; 165:536-549. [PMID: 36762973 PMCID: PMC10903110 DOI: 10.1111/jnc.15781] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 01/16/2023] [Accepted: 02/01/2023] [Indexed: 02/11/2023]
Abstract
Apolipoprotein E (APOE) is a lipid transporter produced predominantly by astrocytes in the brain. The ε4 variant of APOE (APOE4) is the strongest and most common genetic risk factor for Alzheimer's disease (AD). Although the molecular mechanisms of this increased risk are unclear, APOE4 is known to alter immune signaling and lipid and glucose metabolism. Astrocytes provide various forms of support to neurons, including regulating neuronal metabolism and immune responses through cytokine signaling. Changes in astrocyte function because of APOE4 may therefore decrease neuronal support, leaving neurons more vulnerable to stress and disease insults. To determine whether APOE4 alters astrocyte neuronal support functions, we measured glycolytic and oxidative metabolism of neurons treated with conditioned media from APOE4 or APOE3 (the common, risk-neutral variant) primary astrocyte cultures. We found that APOE4 neurons treated with conditioned media from resting APOE4 astrocytes had similar metabolism to APOE3 neurons treated with media from resting APOE3 astrocytes, but treatment with astrocytic conditioned media from astrocytes challenged with amyloid-β (Aβ), a key pathological protein in AD, caused APOE4 neurons to increase their basal mitochondrial and glycolytic metabolic rates more than APOE3 neurons. These changes were not because of differences in astrocytic lactate production or glucose utilization, but instead correlated with increased glycolytic ATP production and a lack of cytokine secretion in response to Aβ. Additionally, we identified that astrocytic cytokine signatures could predict basal metabolism of neurons treated with the astrocytic conditioned media. Together, these findings suggest that in the presence of Aβ, APOE4 astrocytes alter immune and metabolic functions that result in a compensatory increase in neuronal metabolic stress.
Collapse
Affiliation(s)
- Rebecca M. Fleeman
- Department of Neurosurgery, Penn State College of Medicine, Hershey, Pennsylvania, USA
- Department of Pharmacology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Madison K. Kuhn
- Department of Neurosurgery, Penn State College of Medicine, Hershey, Pennsylvania, USA
- Department of Pharmacology, Penn State College of Medicine, Hershey, Pennsylvania, USA
- Department of Biomedical Engineering, Pennsylvania State University, University Park, State College, Pennsylvania, USA
- Center for Neural Engineering, Pennsylvania State University, University Park, State College, Pennsylvania, USA
| | - Dennis C. Chan
- Department of Neurosurgery, Penn State College of Medicine, Hershey, Pennsylvania, USA
- Department of Pharmacology, Penn State College of Medicine, Hershey, Pennsylvania, USA
- Department of Biomedical Engineering, Pennsylvania State University, University Park, State College, Pennsylvania, USA
- Center for Neural Engineering, Pennsylvania State University, University Park, State College, Pennsylvania, USA
| | - Elizabeth A. Proctor
- Department of Neurosurgery, Penn State College of Medicine, Hershey, Pennsylvania, USA
- Department of Pharmacology, Penn State College of Medicine, Hershey, Pennsylvania, USA
- Department of Biomedical Engineering, Pennsylvania State University, University Park, State College, Pennsylvania, USA
- Center for Neural Engineering, Pennsylvania State University, University Park, State College, Pennsylvania, USA
- Department of Engineering Science & Mechanics, Pennsylvania State University, University Park, State College, Pennsylvania, USA
| |
Collapse
|
6
|
Huang Y, Li S, Wang Y, Yan Z, Guo Y, Zhang L. A Novel 5-Chloro-N-phenyl-1H-indole-2-carboxamide Derivative as Brain-Type Glycogen Phosphorylase Inhibitor: Potential Therapeutic Effect on Cerebral Ischemia. Molecules 2022; 27:molecules27196333. [PMID: 36234871 PMCID: PMC9572471 DOI: 10.3390/molecules27196333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 09/20/2022] [Accepted: 09/23/2022] [Indexed: 11/16/2022] Open
Abstract
Brain-type glycogen phosphorylase inhibitors are potential new drugs for treating ischemic brain injury. In our previous study, we reported compound 1 as a novel brain-type glycogen phosphorylase inhibitor with cardioprotective properties. We also found that compound 1 has high blood–brain barrier permeability through the ADMET prediction website. In this study, we deeply analyzed the protective effect of compound 1 on hypoxic-ischemic brain injury, finding that compound 1 could alleviate the hypoxia/reoxygenation (H/R) injury of astrocytes by improving cell viability and reducing LDH leakage rate, intracellular glucose content, and post-ischemic ROS level. At the same time, compound 1 could reduce the level of ATP in brain cells after ischemia, improve cellular energy metabolism, downregulate the degree of extracellular acidification, and improve metabolic acidosis. It could also increase the level of mitochondrial aerobic energy metabolism during brain cell reperfusion, reduce anaerobic glycolysis, and inhibit apoptosis and the expression of apoptosis-related proteins. The above results indicated that compound 1 is involved in the regulation of glucose metabolism, can control cell apoptosis, and has protective and potential therapeutic effects on cerebral ischemia-reperfusion injury, which provides a new reference and possibility for the development of novel drugs for the treatment of ischemic brain injury.
Collapse
Affiliation(s)
- Yatao Huang
- Laboratory of Traditional Chinese Medicine Research and Development of Hebei Province, Institute of Traditional Chinese Medicine, Chengde Medical University, Chengde 067000, China
| | - Shuai Li
- Laboratory of Traditional Chinese Medicine Research and Development of Hebei Province, Institute of Traditional Chinese Medicine, Chengde Medical University, Chengde 067000, China
| | - Youde Wang
- Laboratory of Traditional Chinese Medicine Research and Development of Hebei Province, Institute of Traditional Chinese Medicine, Chengde Medical University, Chengde 067000, China
| | - Zhiwei Yan
- Laboratory of Traditional Chinese Medicine Research and Development of Hebei Province, Institute of Traditional Chinese Medicine, Chengde Medical University, Chengde 067000, China
| | - Yachun Guo
- Department of Pathogen Biology, Chengde Medical University, Chengde 067000, China
- Correspondence: (Y.G.); (L.Z.); Tel.: +86-0314-229-1000 (L.Z.)
| | - Liying Zhang
- Laboratory of Traditional Chinese Medicine Research and Development of Hebei Province, Institute of Traditional Chinese Medicine, Chengde Medical University, Chengde 067000, China
- Correspondence: (Y.G.); (L.Z.); Tel.: +86-0314-229-1000 (L.Z.)
| |
Collapse
|
7
|
Abedi-Gaballu F, Kamal Kazemi E, Salehzadeh SA, Mansoori B, Eslami F, Emami A, Dehghan G, Baradaran B, Mansoori B, Cho WC. Metabolic Pathways in Breast Cancer Reprograming: An Insight to Non-Coding RNAs. Cells 2022; 11:cells11192973. [PMID: 36230935 PMCID: PMC9563138 DOI: 10.3390/cells11192973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/10/2022] [Accepted: 09/19/2022] [Indexed: 11/16/2022] Open
Abstract
Cancer cells reprogram their metabolisms to achieve high energetic requirements and produce precursors that facilitate uncontrolled cell proliferation. Metabolic reprograming involves not only the dysregulation in glucose-metabolizing regulatory enzymes, but also the enzymes engaging in the lipid and amino acid metabolisms. Nevertheless, the underlying regulatory mechanisms of reprograming are not fully understood. Non-coding RNAs (ncRNAs) as functional RNA molecules cannot translate into proteins, but they do play a regulatory role in gene expression. Moreover, ncRNAs have been demonstrated to be implicated in the metabolic modulations in breast cancer (BC) by regulating the metabolic-related enzymes. Here, we will focus on the regulatory involvement of ncRNAs (microRNA, circular RNA and long ncRNA) in BC metabolism, including glucose, lipid and glutamine metabolism. Investigation of this aspect may not only alter the approaches of BC diagnosis and prognosis, but may also open a new avenue in using ncRNA-based therapeutics for BC treatment by targeting different metabolic pathways.
Collapse
Affiliation(s)
- Fereydoon Abedi-Gaballu
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz 51666-14731, Iran
- Department of Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz 51666-16471, Iran
| | - Elham Kamal Kazemi
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz 51666-14731, Iran
- Department of Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz 51666-16471, Iran
| | - Seyed Ahmad Salehzadeh
- Department of Medicinal Biotechnology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran 175-14115, Iran
| | - Behnaz Mansoori
- Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran 175-14115, Iran
| | - Farhad Eslami
- Department of Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz 51666-16471, Iran
| | - Ali Emami
- Department of Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz 51666-16471, Iran
| | - Gholamreza Dehghan
- Department of Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz 51666-16471, Iran
| | - Behzad Baradaran
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz 51666-14731, Iran
| | - Behzad Mansoori
- Cellular and Molecular Oncogenesis Program, The Wistar Institute, Philadelphia, PA 19104, USA
- Correspondence: (B.M.); (W.C.C.)
| | - William C. Cho
- Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong, China
- Correspondence: (B.M.); (W.C.C.)
| |
Collapse
|
8
|
Lactate Supply from Astrocytes to Neurons and its Role in Ischemic Stroke-induced Neurodegeneration. Neuroscience 2022; 481:219-231. [PMID: 34843897 DOI: 10.1016/j.neuroscience.2021.11.035] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 01/10/2023]
Abstract
Glucose transported to the brain is metabolized to lactate in astrocytes and supplied to neuronal cells via a monocarboxylic acid transporter (MCT). Lactate is used in neuronal cells for various functions, including learning and memory formation. Furthermore, lactate can block stroke-induced neurodegeneration. We aimed to clarify the effect of astrocyte-produced lactate on stroke-induced neurodegeneration. Previously published in vivo and in vitro animal and cell studies, respectively, were searched in PubMed, ScienceDirect, and Web of Science. Under physiological conditions, lactate production and release by astrocytes are regulated by changes in lactate dehydrogenase (LDH) and MCT expression. Moreover, considering stroke, lactate production and supply are regulated through hypoxia-inducible factor (HIF)-1α expression, especially with hypoxic stimulation, which may promote neuronal apoptosis; contrastingly, neuronal survival may be promoted via HIF-1α. Stroke stimulation could prevent neurodegeneration through the strong enhancement of lactate production, as well as upregulation of MCT4 expression to accelerate lactate supply. However, studies using astrocytes derived from animal stroke models revealed significantly reduced lactate production and MCT expression. These findings suggest that the lack of lactate supply may strongly contribute to hypoxia-induced neurodegeneration. Furthermore, diminished lactate supply from astrocytes could facilitate stroke-induced neurodegeneration. Therefore, astrocyte-derived lactate may contribute to stroke prevention.
Collapse
|
9
|
Fame RM, Lehtinen MK. Mitochondria in Early Forebrain Development: From Neurulation to Mid-Corticogenesis. Front Cell Dev Biol 2021; 9:780207. [PMID: 34888312 PMCID: PMC8650308 DOI: 10.3389/fcell.2021.780207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 11/10/2021] [Indexed: 01/07/2023] Open
Abstract
Function of the mature central nervous system (CNS) requires a substantial proportion of the body’s energy consumption. During development, the CNS anlage must maintain its structure and perform stage-specific functions as it proceeds through discrete developmental stages. While key extrinsic signals and internal transcriptional controls over these processes are well appreciated, metabolic and mitochondrial states are also critical to appropriate forebrain development. Specifically, metabolic state, mitochondrial function, and mitochondrial dynamics/localization play critical roles in neurulation and CNS progenitor specification, progenitor proliferation and survival, neurogenesis, neural migration, and neurite outgrowth and synaptogenesis. With the goal of integrating neurodevelopmental biologists and mitochondrial specialists, this review synthesizes data from disparate models and processes to compile and highlight key roles of mitochondria in the early development of the CNS with specific focus on forebrain development and corticogenesis.
Collapse
Affiliation(s)
- Ryann M Fame
- Department of Pathology, Boston Children's Hospital, Boston, MA, United States
| | - Maria K Lehtinen
- Department of Pathology, Boston Children's Hospital, Boston, MA, United States
| |
Collapse
|
10
|
Beyer F, Lüdje W, Karpf J, Saher G, Beckervordersandforth R. Distribution of Aldh1L1-CreER T2 Recombination in Astrocytes Versus Neural Stem Cells in the Neurogenic Niches of the Adult Mouse Brain. Front Neurosci 2021; 15:713077. [PMID: 34557065 PMCID: PMC8452868 DOI: 10.3389/fnins.2021.713077] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 08/06/2021] [Indexed: 12/23/2022] Open
Abstract
In the adult central nervous system, neural stem cells (NSCs) reside in two discrete niches: the subependymal zone (SEZ) of the lateral ventricle and the subgranular zone (SGZ) of the dentate gyrus (DG). Here, NSCs represent a population of highly specialized astrocytes that are able to proliferate and give rise to neuronal and glial progeny. This process, termed adult neurogenesis, is extrinsically regulated by other niche cells such as non-stem cell astrocytes. Studying these non-stem cell niche astrocytes and their role during adult neuro- and gliogenesis has been hampered by the lack of genetic tools to discriminate between transcriptionally similar NSCs and niche astrocytes. Recently, Aldh1L1 has been shown to be a pan-astrocyte marker and that its promoter can be used to specifically target astrocytes using the Cre-loxP system. In this study we explored whether the recently described Aldh1L1-CreERT2 mouse line (Winchenbach et al., 2016) can serve to specifically target niche astrocytes without inducing recombination in NSCs in adult neurogenic niches. Using short- and long-term tamoxifen protocols we revealed high recombination efficiency and specificity in non-stem cell astrocytes and little to no recombination in NSCs of the adult DG. However, in the SEZ we observed recombination in ependymal cells, astrocytes, and NSCs, the latter giving rise to neuronal progeny of the rostral migratory stream and olfactory bulb. Thus, we recommend the here described Aldh1L1-CreERT2 mouse line for predominantly studying the functions of non-stem cell astrocytes in the DG under physiological and pathological conditions.
Collapse
Affiliation(s)
- Felix Beyer
- Institute of Biochemistry, Emil-Fischer Center, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
| | - Wichard Lüdje
- Institute of Biochemistry, Emil-Fischer Center, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
| | - Julian Karpf
- Institute of Biochemistry, Emil-Fischer Center, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
| | - Gesine Saher
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Ruth Beckervordersandforth
- Institute of Biochemistry, Emil-Fischer Center, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
| |
Collapse
|
11
|
Benaroya H. Brain energetics, mitochondria, and traumatic brain injury. Rev Neurosci 2021; 31:363-390. [PMID: 32004148 DOI: 10.1515/revneuro-2019-0086] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 11/13/2019] [Indexed: 12/13/2022]
Abstract
We review current thinking about, and draw connections between, brain energetics and metabolism, and between mitochondria and traumatic brain injury. Energy is fundamental to proper brain function. Its creation in a useful form for neurons and glia, and consistently in response to the brain's high energy needs, is critical for physiological pathways. Dysfunction in the mechanisms of energy production is at the center of neurological and neuropsychiatric pathologies. We examine the connections between energetics and mitochondria - the organelle responsible for almost all the energy production in the cell - and how secondary pathologies in traumatic brain injury result from energetic dysfunction. This paper interweaves these topics, a necessity since they are closely coupled, and identifies where there exist a lack of understanding and of data. In addition to summarizing current thinking in these disciplines, our goal is to suggest a framework for the mathematical modeling of mechanisms and pathways based on optimal energetic decisions.
Collapse
Affiliation(s)
- Haym Benaroya
- Department of Mechanical and Aerospace Engineering, Rutgers University, 98 Brett Road, Piscataway, NJ 08854, USA
| |
Collapse
|
12
|
Correia Rocha IR, Chacur M. Modulatory effects of photobiomodulation in the anterior cingulate cortex of diabetic rats. Photochem Photobiol Sci 2021; 20:781-790. [PMID: 34053000 DOI: 10.1007/s43630-021-00059-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 05/25/2021] [Indexed: 10/21/2022]
Abstract
Anterior Cingulate Cortex (ACC) has a crucial contribution to higher order pain processing. Photobiomodulation (PBM) has being used as integrative medicine for pain treatment and for a variety of nervous system disorders. This study evaluated the effects of PBM in the ACC of diabetic rats. Type 1 diabetes was induced by a single dose of streptozotocin (85 mg/Kg). A total of ten sessions of PBM (pulsed gallium-arsenide laser, 904 nm, 9500 Hz, 6.23 J/cm2) was applied to the rat peripheral nervous system. Glial fibrillary acidic protein (GFAP), mu-opioid receptor (MOR), glutamate receptor 1 (GluR1), and glutamic acid decarboxylase (GAD65/67) protein level expression were analyzed in the ACC of diabetic rats treated with PBM. Our data revealed that PBM decreased 79.5% of GFAP protein levels in the ACC of STZ rats. Moreover, STZ + PBM rats had protein levels of MOR increased 14.7% in the ACC. Interestingly, STZ + PBM rats had a decrease in 70.7% of GluR1 protein level in the ACC. Additionally, PBM decreased 45.5% of GAD65/67 protein levels in the ACC of STZ rats.
Collapse
Affiliation(s)
- Igor Rafael Correia Rocha
- Departamento de Anatomia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Avenue Lineu Prestes 2415, room 007, São Paulo, 05508-900, Brazil
| | - Marucia Chacur
- Departamento de Anatomia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Avenue Lineu Prestes 2415, room 007, São Paulo, 05508-900, Brazil.
| |
Collapse
|
13
|
McNeill J, Rudyk C, Hildebrand ME, Salmaso N. Ion Channels and Electrophysiological Properties of Astrocytes: Implications for Emergent Stimulation Technologies. Front Cell Neurosci 2021; 15:644126. [PMID: 34093129 PMCID: PMC8173131 DOI: 10.3389/fncel.2021.644126] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 04/26/2021] [Indexed: 12/12/2022] Open
Abstract
Astrocytes comprise a heterogeneous cell population characterized by distinct morphologies, protein expression and function. Unlike neurons, astrocytes do not generate action potentials, however, they are electrically dynamic cells with extensive electrophysiological heterogeneity and diversity. Astrocytes are hyperpolarized cells with low membrane resistance. They are heavily involved in the modulation of K+ and express an array of different voltage-dependent and voltage-independent channels to help with this ion regulation. In addition to these K+ channels, astrocytes also express several different types of Na+ channels; intracellular Na+ signaling in astrocytes has been linked to some of their functional properties. The physiological hallmark of astrocytes is their extensive intracellular Ca2+ signaling cascades, which vary at the regional, subregional, and cellular levels. In this review article, we highlight the physiological properties of astrocytes and the implications for their function and influence of network and synaptic activity. Furthermore, we discuss the implications of these differences in the context of optogenetic and DREADD experiments and consider whether these tools represent physiologically relevant techniques for the interrogation of astrocyte function.
Collapse
Affiliation(s)
- Jessica McNeill
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | | | | | - Natalina Salmaso
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| |
Collapse
|
14
|
Fleeman RM, Proctor EA. Astrocytic Propagation of Tau in the Context of Alzheimer's Disease. Front Cell Neurosci 2021; 15:645233. [PMID: 33815065 PMCID: PMC8010320 DOI: 10.3389/fncel.2021.645233] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 02/19/2021] [Indexed: 01/14/2023] Open
Abstract
More than 6 million Americans are currently living with Alzheimer's disease (AD), and the incidence is growing rapidly with our aging population. Numerous therapeutics have failed to make it to the clinic, potentially due to a focus on presumptive pathogenic proteins instead of cell-type-specific signaling mechanisms. The tau propagation hypothesis that inter-neuronal tau transfer drives AD pathology has recently garnered attention, as accumulation of pathological tau in the brain has high clinical significance in correlating with progression of cognitive AD symptoms. However, studies on tau pathology in AD are classically neuron-centric and have greatly overlooked cell-type specific effects of tau internalization, degradation, and propagation. While the contribution of microglia to tau processing and propagation is beginning to be recognized and understood, astrocytes, glial cells in the brain important for maintaining neuronal metabolic, synaptic, trophic, and immune function which can produce, internalize, degrade, and propagate tau are understudied in their ability to affect AD progression through tau pathology. Here, we showcase evidence for whether tau uptake by astrocytes may be beneficial or detrimental to neuronal health and how astrocytes and their immunometabolic functions may be key targets for future successful AD therapies.
Collapse
Affiliation(s)
- Rebecca M Fleeman
- Department of Neurosurgery, Department of Pharmacology, College of Medicine, Pennsylvania State University (PSU), Hershey, PA, United States.,Center for Neural Engineering, Pennsylvania State University (PSU), University Park, PA, United States
| | - Elizabeth A Proctor
- Department of Neurosurgery, Department of Pharmacology, College of Medicine, Pennsylvania State University (PSU), Hershey, PA, United States.,Department of Biomedical Engineering, Department of Engineering Science and Mechanics, Center for Neural Engineering, Pennsylvania State University (PSU), University Park, PA, United States
| |
Collapse
|
15
|
Gage MC, Thippeswamy T. Inhibitors of Src Family Kinases, Inducible Nitric Oxide Synthase, and NADPH Oxidase as Potential CNS Drug Targets for Neurological Diseases. CNS Drugs 2021; 35:1-20. [PMID: 33515429 PMCID: PMC7893831 DOI: 10.1007/s40263-020-00787-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/20/2020] [Indexed: 12/21/2022]
Abstract
Neurological diseases share common neuroinflammatory and oxidative stress pathways. Both phenotypic and molecular changes in microglia, astrocytes, and neurons contribute to the progression of disease and present potential targets for disease modification. Src family kinases (SFKs) are present in both neurons and glial cells and are upregulated following neurological insults in both human and animal models. In neurons, SFKs interact with post-synaptic protein domains to mediate hyperexcitability and neurotoxicity. SFKs are upstream of signaling cascades that lead to the modulation of neurotransmitter receptors and the transcription of pro-inflammatory cytokines as well as producers of free radicals through the activation of glia. Inducible nitric oxide synthase (iNOS/NOS-II) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2), the major mediators of reactive nitrogen/oxygen species (RNS/ROS) production in the brain, are also upregulated along with the pro-inflammatory cytokines following neurological insult and contribute to disease progression. Persistent neuronal hyperexcitability, RNS/ROS, and cytokines can exacerbate neurodegeneration, a common pathognomonic feature of the most prevalent neurological disorders such as Alzheimer's disease, Parkinson's disease, and epilepsy. Using a wide variety of preclinical disease models, inhibitors of the SFK-iNOS-NOX2 signaling axis have been tested to cure or modify disease progression. In this review, we discuss the SFK-iNOS-NOX2 signaling pathway and their inhibitors as potential CNS targets for major neurological diseases.
Collapse
Affiliation(s)
- Meghan C. Gage
- Iowa State University, Ames, Iowa, United States of America
| | | |
Collapse
|
16
|
Deme P, Rojas C, Slusher BS, Rais R, Afghah Z, Geiger JD, Haughey NJ. Bioenergetic adaptations to HIV infection. Could modulation of energy substrate utilization improve brain health in people living with HIV-1? Exp Neurol 2020; 327:113181. [PMID: 31930991 PMCID: PMC7233457 DOI: 10.1016/j.expneurol.2020.113181] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 12/10/2019] [Accepted: 01/10/2020] [Indexed: 12/18/2022]
Abstract
The human brain consumes more energy than any other organ in the body and it relies on an uninterrupted supply of energy in the form of adenosine triphosphate (ATP) to maintain normal cognitive function. This constant supply of energy is made available through an interdependent system of metabolic pathways in neurons, glia and endothelial cells that each have specialized roles in the delivery and metabolism of multiple energetic substrates. Perturbations in brain energy metabolism is associated with a number of different neurodegenerative conditions including impairments in cognition associated with infection by the Human Immunodeficiency Type 1 Virus (HIV-1). Adaptive changes in brain energy metabolism are apparent early following infection, do not fully normalize with the initiation of antiretroviral therapy (ART), and often worsen with length of infection and duration of anti-retroviral therapeutic use. There is now a considerable amount of cumulative evidence that suggests mild forms of cognitive impairments in people living with HIV-1 (PLWH) may be reversible and are associated with specific modifications in brain energy metabolism. In this review we discuss brain energy metabolism with an emphasis on adaptations that occur in response to HIV-1 infection. The potential for interventions that target brain energy metabolism to preserve or restore cognition in PLWH are also discussed.
Collapse
Affiliation(s)
- Pragney Deme
- The Johns Hopkins University School of Medicine, Department of Neurology, United States
| | - Camilo Rojas
- The Johns Hopkins University School of Medicine, Department of Comparative Medicine and Pathobiology, United States
| | - Barbara S Slusher
- The Johns Hopkins University School of Medicine, Department of Neurology, United States; The Johns Hopkins University School of Medicine, Department of The Solomon H. Snyder Department of Neuroscience, United States; The Johns Hopkins University School of Medicine, Department of Comparative Medicine and Pathobiology, United States; The Johns Hopkins University School of Medicine, Department of Psychiatry, United States
| | - Raina Rais
- The Johns Hopkins University School of Medicine, Department of Neurology, United States; The Johns Hopkins University School of Medicine, Department of The Solomon H. Snyder Department of Neuroscience, United States; The Johns Hopkins University School of Medicine, Department of Comparative Medicine and Pathobiology, United States; The Johns Hopkins University School of Medicine, Department of Psychiatry, United States
| | - Zahra Afghah
- The University of North Dakota School of Medicine and Health Sciences, Department of Biomedical Sciences, United States
| | - Jonathan D Geiger
- The University of North Dakota School of Medicine and Health Sciences, Department of Biomedical Sciences, United States
| | - Norman J Haughey
- The Johns Hopkins University School of Medicine, Department of Neurology, United States; The Johns Hopkins University School of Medicine, Department of Psychiatry, United States.
| |
Collapse
|
17
|
Leardini-Tristão M, Andrade G, Garcia C, Reis PA, Lourenço M, Moreira ETS, Lima FRS, Castro-Faria-Neto HC, Tibirica E, Estato V. Physical exercise promotes astrocyte coverage of microvessels in a model of chronic cerebral hypoperfusion. J Neuroinflammation 2020; 17:117. [PMID: 32299450 PMCID: PMC7161182 DOI: 10.1186/s12974-020-01771-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 03/12/2020] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Brain circulation disorders such as chronic cerebral hypoperfusion have been associated with a decline in cognitive function during the development of dementia. Astrocytes together with microglia participate in the immune response in the CNS and make them potential sentinels in the brain parenchyma. In addition, astrocytes coverage integrity has been related to brain homeostasis. Currently, physical exercise has been proposed as an effective intervention to promote brain function improvement. However, the neuroprotective effects of early physical exercise on the astrocyte communication with the microcirculation and the microglial activation in a chronic cerebral hypoperfusion model are still unclear. The aim of this study was to investigate the impact of early intervention with physical exercise on cognition, brain microcirculatory, and inflammatory parameters in an experimental model of chronic cerebral hypoperfusion induced by permanent bilateral occlusion of the common carotid arteries (2VO). METHODS Wistar rats aged 12 weeks were randomly divided into four groups: Sham-sedentary group (Sham-Sed), Sham-exercised group (Sham-Ex), 2VO-sedentary group (2VO-Sed), and 2VO-exercised group (2VO-Ex). The early intervention with physical exercise started 3 days after 2VO or Sham surgery during 12 weeks. Then, the brain functional capillary density and endothelial-leukocyte interactions were evaluated by intravital microscopy; cognitive function was evaluated by open-field test; hippocampus postsynaptic density protein 95 and synaptophysin were evaluated by western blotting; astrocytic coverage of the capillaries, microglial activation, and structural capillary density were evaluated by immunohistochemistry. RESULTS Early moderate physical exercise was able to normalize functional capillary density and reduce leukocyte rolling in the brain of animals with chronic cerebral hypoperfusion. These effects were accompanied by restore synaptic protein and the improvement of cognitive function. In addition, early moderate exercise improves astrocytes coverage in blood vessels of the cerebral cortex and hippocampus, decreases microglial activation in the hippocampus, and improves structural capillaries in the hippocampus. CONCLUSIONS Microcirculatory and inflammatory changes in the brain appear to be involved in triggering a cognitive decline in animals with chronic cerebral ischemia. Therefore, early intervention with physical exercise may represent a preventive approach to neurodegeneration caused by chronic cerebral hypoperfusion.
Collapse
Affiliation(s)
- Marina Leardini-Tristão
- Laboratory of Immunopharmacology, Oswaldo Cruz Foundation, Av. Brasil, 4365, Manguinhos, Rio de Janeiro, 21040-900, Brazil.,Laboratory of Cardiovascular Investigation, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Giulia Andrade
- Laboratory of Immunopharmacology, Oswaldo Cruz Foundation, Av. Brasil, 4365, Manguinhos, Rio de Janeiro, 21040-900, Brazil.,Laboratory of Cardiovascular Investigation, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Celina Garcia
- Laboratory of Glial Cell Biology, Biomedical Sciences Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Patrícia A Reis
- Laboratory of Immunopharmacology, Oswaldo Cruz Foundation, Av. Brasil, 4365, Manguinhos, Rio de Janeiro, 21040-900, Brazil
| | - Millena Lourenço
- Laboratory of Immunopharmacology, Oswaldo Cruz Foundation, Av. Brasil, 4365, Manguinhos, Rio de Janeiro, 21040-900, Brazil
| | - Emilio T S Moreira
- Laboratory of Immunopharmacology, Oswaldo Cruz Foundation, Av. Brasil, 4365, Manguinhos, Rio de Janeiro, 21040-900, Brazil
| | - Flavia R S Lima
- Laboratory of Glial Cell Biology, Biomedical Sciences Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Hugo C Castro-Faria-Neto
- Laboratory of Immunopharmacology, Oswaldo Cruz Foundation, Av. Brasil, 4365, Manguinhos, Rio de Janeiro, 21040-900, Brazil
| | - Eduardo Tibirica
- Laboratory of Cardiovascular Investigation, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.,National Institute of Cardiology, Rio de Janeiro, Brazil
| | - Vanessa Estato
- Laboratory of Immunopharmacology, Oswaldo Cruz Foundation, Av. Brasil, 4365, Manguinhos, Rio de Janeiro, 21040-900, Brazil. .,Laboratory of Cardiovascular Investigation, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
| |
Collapse
|
18
|
Garcia G, Paul S, Beshara S, Ramanujan VK, Ramaiah A, Nielsen-Saines K, Li MMH, French SW, Morizono K, Kumar A, Arumugaswami V. Hippo Signaling Pathway Has a Critical Role in Zika Virus Replication and in the Pathogenesis of Neuroinflammation. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 190:844-861. [PMID: 32035058 DOI: 10.1016/j.ajpath.2019.12.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/22/2019] [Accepted: 12/17/2019] [Indexed: 02/06/2023]
Abstract
Zika virus (ZIKV) is a reemerging human pathogen that causes congenital abnormalities, including microcephaly and eye disease. The cellular/molecular basis of ZIKV and host interactions inducing ocular and neuronal pathogenesis are unclear. Herein, we noted that the Hippo/Salvador-Warts-Hippo signaling pathway, which controls organ size through progenitor cell proliferation and differentiation, is dysregulated after ZIKV infection. In human fetal retinal pigment epithelial cells, there is an early induction of transcriptional coactivator, Yes-associated protein (YAP), which is later degraded with a corresponding activation of the TANK binding kinase 1/interferon regulatory factor 3 type I interferon pathway. YAP/transcriptional co-activator with a PDZ-binding domain (TAZ) silencing results in reduced ZIKV replication, indicating a direct role of Hippo pathway in regulating ZIKV infection. Using an in vivo Ifnar1-/- knockout mouse model, ZIKV infection was found to reduce YAP/TAZ protein levels while increasing phosphorylated YAP Ser127 in the retina and brain. Hippo pathway is activated in major cellular components of the blood-brain barrier, including endothelial cells and astrocytes. In addition, this result suggests AMP-activated protein kinase signaling pathway's role in regulating YAP/TAZ in ZIKV-infected cells. These data demonstrate that ZIKV infection might initiate a cross talk among AMP-activated protein kinase-Hippo-TBK1 pathways, which could regulate antiviral and energy stress responses during oculoneuronal inflammation.
Collapse
Affiliation(s)
- Gustavo Garcia
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, California
| | - Sayan Paul
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, California; Department of Biotechnology, Manonmaniam Sundaranar University, Tirunelveli, India
| | - Sara Beshara
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, California
| | | | - Arunachalam Ramaiah
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California
| | - Karin Nielsen-Saines
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, California
| | - Melody M H Li
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California
| | - Samuel W French
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, California
| | - Kouki Morizono
- Division of Hematology and Oncology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California; UCLA AIDS Institute, David Geffen School of Medicine, University of California, Los Angeles, California
| | - Ashok Kumar
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University, Detroit, Michigan
| | - Vaithilingaraja Arumugaswami
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, California; Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California; Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, California.
| |
Collapse
|
19
|
Dossi G, Squarcina L, Rango M. In Vivo Mitochondrial Function in Idiopathic and Genetic Parkinson's Disease. Metabolites 2019; 10:metabo10010019. [PMID: 31905632 PMCID: PMC7023121 DOI: 10.3390/metabo10010019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 12/20/2019] [Accepted: 12/26/2019] [Indexed: 01/26/2023] Open
Abstract
Parkinson’s disease (PD) is associated with brain mitochondrial dysfunction. High-energy phosphates (HEPs), which rely on mitochondrial functioning, may be considered potential biomarkers for PD. Phosphorus magnetic resonance spectroscopy (31P-MRS) is a suitable tool to explore in vivo cerebral energetics. We considered 10 31P-MRS studies in order to highlight the main findings about brain energetic compounds in patients affected by idiopathic PD and genetic PD. The studies investigated several brain areas such as frontal lobes, occipital lobes, temporoparietal cortex, visual cortex, midbrain, and basal ganglia. Resting-state studies reported contrasting results showing decreased as well as normal or increased HEPs levels in PD patients. Functional studies revealed abnormal PCr + βATP levels in PD subjects during the recovery phase and abnormal values at rest, during activation and recovery in one PD subject with PINK1 gene mutation suggesting that mitochondrial machinery is more impaired in PD patients with PINK1 gene mutation. PD is characterized by energetics impairment both in idiopathic PD as well as in genetic PD, suggesting that mitochondrial dysfunction underlies the disease. Studies are still sparse and sometimes contrasting, maybe due to different methodological approaches. Further studies are needed to better assess the role of mitochondria in the PD development.
Collapse
|
20
|
Parra-Abarca J, Rivera-Ramírez N, Villa-Maldonado LF, García-Hernández U, Aguilera P, Arias-Montaño JA. Histamine H 1 and H 3 receptor activation increases the expression of Glucose Transporter 1 (GLUT-1) in rat cerebro-cortical astrocytes in primary culture. Neurochem Int 2019; 131:104565. [PMID: 31586591 DOI: 10.1016/j.neuint.2019.104565] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 09/11/2019] [Accepted: 10/02/2019] [Indexed: 01/05/2023]
Abstract
Astrocytes take up glucose via the 45 kDa isoform of the Glucose Transporter 1 (GLUT-1), and in this work we have investigated whether histamine regulates GLUT-1 expression in rat cerebro-cortical astrocytes in primary culture. Cultured astrocytes expressed histamine H1 and H3 receptors (H1Rs and H3Rs) as evaluated by radioligand binding. Receptor functionality was confirmed by the increase in the intracellular concentration of Ca2+ (H1R) and the inhibition of forskolin-induced cAMP accumulation (H3R). Quantitative RT-PCR showed that histamine and selective H1R and H3R agonists (1 h incubation) significantly increased GLUT-1 mRNA to 153 ± 7, 163 ± 2 and 168 ± 13% of control values, respectively. In immunoblot assays, incubation (3 h) with histamine or H1R and H3R agonists increased GLUT-1 protein levels to 224 ± 12, 305 ± 11 and 193 ± 13% of control values, respectively, an action confirmed by inmunocytochemistry. The effects of H1R and H3R agonists were blocked by the selective antagonists mepyramine (H1R) and clobenpropit (H3R). The pharmacological inhibition of protein kinase C (PKC) prevented the increase in GLUT-1 protein induced by either H1R or H3R activation. Furthermore, histamine increased ERK-1/2 phosphorylation, and the effect of H1R and H3R activation on GLUT-1 protein levels was reduced or prevented, respectively, by MEK-1/2 inhibition. These results indicate that by activating H1Rs and H3Rs histamine regulates the expression of GLUT-1 by astrocytes. The effect appears to involve the phospholipase C (PLC) → diacylglycerol (DAG)/Ca2+→ PKC and PLC → DAG/Ca2+ → PKC → MAPK pathways.
Collapse
Affiliation(s)
- Juan Parra-Abarca
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Zacatenco, 07360, Ciudad de México, Mexico
| | - Nayeli Rivera-Ramírez
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Zacatenco, 07360, Ciudad de México, Mexico
| | - Luis-Fernando Villa-Maldonado
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Zacatenco, 07360, Ciudad de México, Mexico
| | - Ubaldo García-Hernández
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Zacatenco, 07360, Ciudad de México, Mexico
| | - Penélope Aguilera
- Laboratorio de Patología Vascular Cerebral, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Insurgentes Sur 3877, La Fama, 14269, Ciudad de México, Mexico
| | - José-Antonio Arias-Montaño
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Zacatenco, 07360, Ciudad de México, Mexico.
| |
Collapse
|
21
|
Prospects and challenges of imaging neuroinflammation beyond TSPO in Alzheimer's disease. Eur J Nucl Med Mol Imaging 2019; 46:2831-2847. [PMID: 31396666 PMCID: PMC6879435 DOI: 10.1007/s00259-019-04462-w] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 07/24/2019] [Indexed: 02/06/2023]
Abstract
Neuroinflammation, as defined by the activation of microglia and astrocytes, has emerged in the last years as a key element of the pathogenesis of neurodegenerative diseases based on genetic findings and preclinical and human studies. This has raised the need for new methodologies to assess and follow glial activation in patients, prompting the development of PET ligands for molecular imaging of glial cells and novel structural MRI and DTI tools leading to a multimodal approach. The present review describes the recent advancements in microglia and astrocyte biology in the context of health, ageing, and Alzheimer's disease, the most common dementia worldwide. The review further delves in molecular imaging discussing the challenges associated with past and present targets, including conflicting findings, and finally, presenting novel methodologies currently explored to improve our in vivo knowledge of the neuroinflammatory patterns in Alzheimer's disease. With glial cell activation as a potential therapeutic target in neurodegenerative diseases, the translational research between cell biologists, chemists, physicists, radiologists, and neurologists should be strengthened.
Collapse
|
22
|
Potokar M, Jorgačevski J, Zorec R. Astrocytes in Flavivirus Infections. Int J Mol Sci 2019; 20:ijms20030691. [PMID: 30736273 PMCID: PMC6386967 DOI: 10.3390/ijms20030691] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 01/27/2019] [Accepted: 01/29/2019] [Indexed: 12/14/2022] Open
Abstract
Virus infections of the central nervous system (CNS) can manifest in various forms of inflammation, including that of the brain (encephalitis) and spinal cord (myelitis), all of which may have long-lasting deleterious consequences. Although the knowledge of how different viruses affect neural cells is increasing, understanding of the mechanisms by which cells respond to neurotropic viruses remains fragmented. Several virus types have the ability to infect neural tissue, and astrocytes, an abundant and heterogeneous neuroglial cell type and a key element providing CNS homeostasis, are one of the first CNS cell types to get infected. Astrocytes are morphologically closely aligned with neuronal synapses, blood vessels, and ventricle cavities, and thereby have the capacity to functionally interact with neurons and endothelial cells. In this review, we focus on the responses of astrocytes to infection by neurotropic flaviviruses, including tick-borne encephalitis virus (TBEV), Zika virus (ZIKV), West Nile virus (WNV), and Japanese encephalitis virus (JEV), which have all been confirmed to infect astrocytes and cause multiple CNS defects. Understanding these mechanisms may help design new strategies to better contain and mitigate virus- and astrocyte-dependent neuroinflammation.
Collapse
Affiliation(s)
- Maja Potokar
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia.
- Celica BIOMEDICAL, Tehnološki park 24, 1000 Ljubljana, Slovenia.
| | - Jernej Jorgačevski
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia.
- Celica BIOMEDICAL, Tehnološki park 24, 1000 Ljubljana, Slovenia.
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia.
- Celica BIOMEDICAL, Tehnološki park 24, 1000 Ljubljana, Slovenia.
| |
Collapse
|
23
|
Stevenson ME, Lensmire NA, Swain RA. Astrocytes and radial glia-like cells, but not neurons, display a nonapoptotic increase in caspase-3 expression following exercise. Brain Behav 2018; 8:e01110. [PMID: 30240148 PMCID: PMC6192401 DOI: 10.1002/brb3.1110] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 06/18/2018] [Accepted: 08/05/2018] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Exercise induces plasticity in the hippocampus, which includes increases in neurogenesis, the proliferation of new neurons, and angiogenesis, the sprouting of new capillaries from preexisting blood vessels. Following exercise, astrocytes also undergo morphological changes that parallel the events occurring in the neurovascular system. Interestingly, there have also been reports of apoptosis in the hippocampus following aerobic exercise. This experiment aimed to identify which population of hippocampal cells undergoes apoptosis after an acute bout of exercise. METHODS Cleaved caspase-3, a terminal protein in the apoptotic cascade, was initially used to identify apoptotic cells in the hippocampus after rats completed an acute bout of exercise. Next, the proportion of immature neurons, adult neurons, astrocytes, or radial glia-like cells expressing cleaved caspase-3 was quantified. TUNEL staining was completed as a second measure of apoptosis. RESULTS Following exercise, cleaved caspase-3 expression was increased in the CA1 and DG regions of the hippocampus. Cleaved caspase-3 was not highly expressed in neuronal populations, and expression was not increased in these cells postexercise. Instead, cleaved caspase-3 was predominantly expressed in astrocytes. Following exercise, there was an increased number of cleaved caspase-3 positive astrocytes in DG and CA1, and cleaved caspase-3 positive radial glia-like cells located in the subgranular zone. To determine whether cleaved caspase-3 expression in these glial cells was associated with apoptosis, a TUNEL assay was completed. TUNEL staining was negligible in all groups and did not mirror the pattern of caspase-3 labeling. CONCLUSIONS Cleaved caspase-3 expression was detected largely in non-neuronal cell populations, and the pattern of cleaved caspase-3 expression did not match that of TUNEL. This suggests that after exercise, cleaved caspase-3 expression may serve a nonapoptotic role in these hippocampal astrocytes and radial glia-like cells. It will be important to identify the function of exercise-induced cleaved caspase-3 expression in the future experiments.
Collapse
Affiliation(s)
| | - Nicole A. Lensmire
- Department of PsychologyUniversity of Wisconsin‐MilwaukeeMilwaukeeWisconsin
| | - Rodney A. Swain
- Department of PsychologyUniversity of Wisconsin‐MilwaukeeMilwaukeeWisconsin
| |
Collapse
|
24
|
Brazhe AR, Verisokin AY, Verveyko DV, Postnov DE. Sodium-Calcium Exchanger Can Account for Regenerative Ca 2+ Entry in Thin Astrocyte Processes. Front Cell Neurosci 2018; 12:250. [PMID: 30154700 PMCID: PMC6102320 DOI: 10.3389/fncel.2018.00250] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 07/23/2018] [Indexed: 01/05/2023] Open
Abstract
Calcium transients in thin astrocytic processes can be important in synaptic plasticity, but their mechanism is not completely understood. Clearance of synaptic glutamate leads to increase in astrocytic sodium. This can electrochemically favor the reverse mode of the Na/Ca-exchanger (NCX) and allow calcium into the cell, accounting for activity-dependent calcium transients in perisynaptic astrocytic processes. However, cytosolic sodium and calcium are also allosteric regulators of the NCX, thus adding kinetic constraints on the NCX-mediated fluxes and providing for complexity of the system dynamics. Our modeling indicates that the calcium-dependent activation and also calcium-dependent escape from the sodium-mediated inactive state of the NCX in astrocytes can form a positive feedback loop and lead to regenerative calcium influx. This can result in sodium-dependent amplification of calcium transients from nearby locations or other membrane mechanisms. Prolonged conditions of elevated sodium, for example in ischemia, can also lead to bistability in cytosolic calcium levels, where a delayed transition to the high-calcium state can be triggered by a short calcium transient. These theoretical predictions call for a dedicated experimental estimation of the kinetic parameters of the astrocytic Na/Ca-exchanger.
Collapse
Affiliation(s)
- Alexey R. Brazhe
- Department of Biophysics, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | | | - Darya V. Verveyko
- Department of Theoretical Physics, Kursk State University, Kursk, Russia
| | | |
Collapse
|
25
|
Madji Hounoum B, Blasco H, Coque E, Vourc'h P, Emond P, Corcia P, Andres CR, Raoul C, Mavel S. The Metabolic Disturbances of Motoneurons Exposed to Glutamate. Mol Neurobiol 2018; 55:7669-7676. [PMID: 29435916 DOI: 10.1007/s12035-018-0945-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 01/31/2018] [Indexed: 12/13/2022]
Abstract
Glutamate-induced excitotoxicity is considered as one of the major pathophysiological factors of motoneuron death in amyotrophic lateral sclerosis and other motoneuron diseases. In order to expand our knowledge on mechanisms of glutamate-induced excitotoxicity, the present study proposes to determine the metabolic consequences of glutamate and astrocytes in primary enriched motoneuron culture. Using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS), we showed that the presence of astrocytes and glutamate profoundly modified the metabolic profile of motoneurons. Our study highlights for the first time that crosstalk between astrocytes and enriched motoneuron culture induced alterations in phenylalanine, tryptophan, purine, arginine, proline, aspartate, and glutamate metabolism in motoneurons. We observed that astrocytes modulate the sensitivity of motoneurons to glutamate, since metabolites altered by glutamate in motoneurons cultured alone were different (except 5-hydroxylysine) from those altered in co-cultured motoneurons. Our findings provide new insight into the metabolic alterations associated to astrocytes and glutamate in motoneurons and provide opportunities to identify novel therapeutic targets.
Collapse
Affiliation(s)
- Blandine Madji Hounoum
- INSERM U930 "Imagerie et Cerveau," CHRU de Tours, Université François-Rabelais, Tours, France
| | - Hélène Blasco
- INSERM U930 "Imagerie et Cerveau," CHRU de Tours, Université François-Rabelais, Tours, France.,Laboratoire de Biochimie et de Biologie Moléculaire, Hôpital Bretonneau, CHRU de Tours, Tours, France
| | - Emmanuelle Coque
- The Institute for Neurosciences of Montpellier, Inserm UMR1051, Univ Montpellier, Saint Eloi Hospital, Montpellier, France
| | - Patrick Vourc'h
- INSERM U930 "Imagerie et Cerveau," CHRU de Tours, Université François-Rabelais, Tours, France.,Laboratoire de Biochimie et de Biologie Moléculaire, Hôpital Bretonneau, CHRU de Tours, Tours, France
| | - Patrick Emond
- INSERM U930 "Imagerie et Cerveau," CHRU de Tours, Université François-Rabelais, Tours, France
| | - Philippe Corcia
- INSERM U930 "Imagerie et Cerveau," CHRU de Tours, Université François-Rabelais, Tours, France.,Centre SLA, Service de Neurologie, CHRU de Tours, Tours, France
| | - Christian R Andres
- INSERM U930 "Imagerie et Cerveau," CHRU de Tours, Université François-Rabelais, Tours, France.,Laboratoire de Biochimie et de Biologie Moléculaire, Hôpital Bretonneau, CHRU de Tours, Tours, France
| | - Cédric Raoul
- The Institute for Neurosciences of Montpellier, Inserm UMR1051, Univ Montpellier, Saint Eloi Hospital, Montpellier, France
| | - Sylvie Mavel
- INSERM U930 "Imagerie et Cerveau," CHRU de Tours, Université François-Rabelais, Tours, France. .,UFR Pharmacie, INSERM U930, 31 av Monge, 37200, Tours, France.
| |
Collapse
|
26
|
Hascup KN, Lynn MK, Fitzgerald PJ, Randall S, Kopchick JJ, Boger HA, Bartke A, Hascup ER. Enhanced Cognition and Hypoglutamatergic Signaling in a Growth Hormone Receptor Knockout Mouse Model of Successful Aging. J Gerontol A Biol Sci Med Sci 2017; 72:329-337. [PMID: 27208894 DOI: 10.1093/gerona/glw088] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 04/25/2016] [Indexed: 01/19/2023] Open
Abstract
Growth hormone receptor knockout (GHR-KO) mice are long lived with improved health span, making this an excellent model system for understanding biochemical mechanisms important to cognitive reserve. The purpose of the present study was to elucidate differences in cognition and glutamatergic dynamics between aged (20- to 24-month-old) GHR-KO and littermate controls. Glutamate plays a critical role in hippocampal learning and memory and is implicated in several neurodegenerative disorders, including Alzheimer's disease. Spatial learning and memory were assessed using the Morris water maze (MWM), whereas independent dentate gyrus (DG), CA3, and CA1 basal glutamate, release, and uptake measurements were conducted in isoflurane anesthetized mice utilizing an enzyme-based microelectrode array (MEA) coupled with constant potential amperometry. These MEAs have high temporal and low spatial resolution while causing minimal damage to the surrounding parenchyma. Littermate controls performed worse on the memory portion of the MWM behavioral task and had elevated DG, CA3, and CA1 basal glutamate and stimulus-evoked release compared with age-matched GHR-KO mice. CA3 basal glutamate negatively correlated with MWM performance. These results support glutamatergic regulation in learning and memory and may have implications for therapeutic targets to delay the onset of, or reduce cognitive decline, in Alzheimer's disease.
Collapse
Affiliation(s)
- Kevin N Hascup
- Department of Neurology, Center for Alzheimer's Disease and Related Disorders, Southern Illinois University School of Medicine, Springfield
| | - Mary K Lynn
- Department of Neuroscience, Medical University of South Carolina, Charleston
| | - Patrick J Fitzgerald
- Department of Neurology, Center for Alzheimer's Disease and Related Disorders, Southern Illinois University School of Medicine, Springfield
| | - Shari Randall
- Department of Neurology, Center for Alzheimer's Disease and Related Disorders, Southern Illinois University School of Medicine, Springfield
| | - John J Kopchick
- Edison Biotechnology Institute, Department of Biomedical Sciences, Ohio University, Athens
| | - Heather A Boger
- Department of Neuroscience, Medical University of South Carolina, Charleston.,Center on Aging, Medical University of South Carolina, Charleston
| | | | - Erin R Hascup
- Department of Neurology, Center for Alzheimer's Disease and Related Disorders, Southern Illinois University School of Medicine, Springfield.,Department of Pharmacology, Southern Illinois University School of Medicine, Springfield
| |
Collapse
|
27
|
Thomas SC, Alhasawi A, Appanna VP, Auger C, Appanna VD. Brain metabolism and Alzheimer's disease: the prospect of a metabolite-based therapy. J Nutr Health Aging 2015; 19:58-63. [PMID: 25560817 DOI: 10.1007/s12603-014-0511-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The brain is one of the most energy-demanding organs in the body. It has evolved intricate metabolic networks to fulfill this need and utilizes a variety of substrates to generate ATP, the universal energy currency. Any disruption in the supply of energy results in various abnormalities including Alzheimer's disease (AD), a condition with markedly diminished cognitive ability. Astrocytes are an important participant in maintaining the cerebral ATP budget. However, under oxidative stress induced by numerous factors including aluminum toxicity, the ability of astroctyes to generate ATP is impaired due to dysfunctional mitochondria. This leads to globular, glycolytic, lipogenic and ATP-deficient astrocytes, cerebral characteristics common in AD patients. The reversal of these perturbations by such natural metabolites as pyruvate, α-ketoglutarate, acetoacetate and L-carnitine provides valuable therapeutic cues against AD.
Collapse
Affiliation(s)
- S C Thomas
- Vasu D. Appanna, Faculty of Science and Engineering, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada. Phone: (705) 675-1151, ext. 2112, Fax: (705) 675-4844. E-mail:
| | | | | | | | | |
Collapse
|
28
|
Vardjan N, Kreft M, Zorec R. Dynamics of β-adrenergic/cAMP signaling and morphological changes in cultured astrocytes. Glia 2014; 62:566-79. [PMID: 24464905 DOI: 10.1002/glia.22626] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 11/05/2013] [Accepted: 12/20/2013] [Indexed: 11/09/2022]
Abstract
The morphology of astrocytes, likely regulated by cAMP, determines the structural association between astrocytes and the synapse, consequently modulating synaptic function. β-Adrenergic receptors (β-AR), which increase cytosolic cAMP concentration ([cAMP]i ), may affect cell morphology. However, the real-time dynamics of β-AR-mediated cAMP signaling in single live astrocytes and its effect on cell morphology have not been studied. We used the fluorescence resonance energy transfer (FRET)-based cAMP biosensor Epac1-camps to study time-dependent changes in [cAMP]i ; morphological changes in primary rat astrocytes were monitored by real-time confocal microscopy. Stimulation of β-AR by adrenaline, noradrenaline, and isoprenaline, a specific agonist of β-AR, rapidly increased [cAMP]i (∼15 s). The FRET signal response, mediated via β-AR, was faster than in the presence of forskolin (twofold) and dibutyryl-cAMP (>35-fold), which directly activate adenylyl cyclase and Epac1-camps, respectively, likely due to slow entry of these agents into the cytosol. Oscillations in [cAMP]i have not been recorded, indicating that cAMP-dependent processes operate in a slow time domain. Most Epac1-camps expressing astrocytes revealed a morphological change upon β-AR activation and attained a stellate morphology within 1 h. The morphological changes exhibited a bell-shaped dependency on [cAMP]i . The 5-10% decrease in cell cross-sectional area and the 30-50% increase in cell perimeter are likely due to withdrawal of the cytoplasm to the perinuclear region and the appearance of protrusions on the surface of astrocytes. Because astrocyte processes ensheath neurons, β-AR/cAMP-mediated morphological changes can modify the geometry of the extracellular space, affecting synaptic, neuronal, and astrocyte functions in health and disease.
Collapse
Affiliation(s)
- Nina Vardjan
- Celica Biomedical Center, Tehnološki Park 24, Ljubljana, Slovenia; Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, Ljubljana, Slovenia
| | | | | |
Collapse
|
29
|
Choi KM, Kim JY, Kim Y. Distribution of the Immunoreactivity for Glycoprotein M6B in the Neurogenic Niche and Reactive Glia in the Injury Penumbra Following Traumatic Brain Injury in Mice. Exp Neurobiol 2013; 22:277-82. [PMID: 24465143 PMCID: PMC3897689 DOI: 10.5607/en.2013.22.4.277] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 11/07/2013] [Accepted: 11/07/2013] [Indexed: 11/19/2022] Open
Abstract
The location and morphology of astrocytes are known to contribute to their diversity, and this diversity is often associated with their selective functions. However, molecular markers for astrocyte subtypes are largely unknown. In this study, we found that the immunoreactivity for glycoprotein GPM6B (M6B-IR) is preferentially expressed in the astrocytes associated with ventricles or neurogenic regions of the adult mouse brain. In particular, M6B-IR in the neurogenic niche was confined to glial fibrillary acidic protein- or nestin-expressing neural stem cells. Furthermore, in the injury penumbra, reactive astrocytes expressing nestin also exhibited strong M6B-IR. These results reveal that GPM6B is a potential molecular marker for a subset of astrocytes, as well as for the injury-dependent activation of astrocytes.
Collapse
Affiliation(s)
- Kyung Mee Choi
- Department of Anatomy, Korea University College of Medicine, Seoul 136-705, Korea
| | - Joo Yeon Kim
- Department of Anatomy, Korea University College of Medicine, Seoul 136-705, Korea
| | - Younghwa Kim
- Department of Emergency Medical Technology, College of Nursing and Public Health, Kyungil University, Gyeongsan 721-701, Korea
| |
Collapse
|
30
|
The bioenergetic status relates to dopamine neuron loss in familial PD with PINK1 mutations. PLoS One 2012; 7:e51308. [PMID: 23251494 PMCID: PMC3519591 DOI: 10.1371/journal.pone.0051308] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 10/31/2012] [Indexed: 02/03/2023] Open
Abstract
Mutations in the PINK1 gene cause autosomal recessive familial Parkinson’s disease (PD). The gene encodes a mitochondrial protein kinase that plays an important role in maintaining mitochondrial function and integrity. However, the pathophysiological link between mutation-related bioenergetic deficits and the degenerative process in dopaminergic neurons remains to be elucidated. We performed phosphorous (31P) and proton (1H) 3-T magnetic resonance spectroscopic imaging (MRSI) in 11 members of a German family with hereditary PD due to PINK1 mutations (PARK6) compared to 23 age-matched controls. All family members had prior 18-Fluorodopa (FDOPA) positron emission tomography (PET). The striatal FDOPA uptake was correlated with quantified metabolic brain mapping in MRSI. At group level, the heterozygous PINK1 mutation carriers did not show any MRSI abnormalities relative to controls. In contrast, homozygous individuals with manifest PD had putaminal GPC, PCr, HEP and β-ATP levels well above the 2SD range of controls. Across all subjects, the FDOPA Ki values correlated positively with MI (r = 0.879, p<0.001) and inversely with β-ATP (r = −0.784, p = 0.008) and GPC concentrations (r = −0.651, p = 0.030) in the putamen. Our combined imaging data suggest that the dopaminergic deficit in this family with PD due to PINK1 mutations relates to osmolyte dysregulation, while the delivery of high energy phosphates was preserved. Our results corroborate the hypothesis that PINK1 mutations result in reduced neuronal survival, most likely due to impaired cellular stress resistance.
Collapse
|
31
|
Neurotoxins released from interferon-gamma-stimulated human astrocytes. Neuroscience 2012; 229:164-75. [PMID: 23098801 DOI: 10.1016/j.neuroscience.2012.10.033] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 10/09/2012] [Accepted: 10/14/2012] [Indexed: 12/29/2022]
Abstract
Astrocytes become activated in degenerative neurological diseases. In order to gain a greater understanding of the inflammatory factors released upon activation, we stimulated adult human astrocytes with interferon-gamma and examined the resultant conditioned medium (CM) for toxicity against differentiated human neuroblastoma SH-SY5Y cells. Cell death was measured by lactate dehydrogenase release assay. We then used various treatments of the media to determine the distribution and nature of the toxic components. Removal of interleukin-6 by a specific antibody reduced the toxicity by 22%. Blockade of proteases with an inhibitor cocktail reduced it by a further 22%. When oxygen-free radical production was blocked with NADPH oxidase inhibitors, the toxicity was reduced by 15.4%. When prostaglandin production was blocked by cyclooxygenase inhibitors, the toxicity of the CM was reduced by 14.5%. When glutamate was removed by treatment with glutamate decarboxylase, the toxicity was reduced by 10.3%. When the inhibitors were added together to the astrocyte culture, the total toxicity of the CM was reduced by 91%. This was in reasonable agreement with the 85.37% total obtained by adding the individual components. The data show that activated astrocytes release a specific combination of neurotoxic compounds. They suggest that effective anti-inflammatory treatment of such neurodegenerative diseases as Alzheimer's disease, Parkinson's disease and Amyotrophic lateral sclerosis could be improved by using an appropriate combination of anti-inflammatory agents instead of relying on any single agent.
Collapse
|
32
|
Foo K, Blumenthal L, Man HY. Regulation of neuronal bioenergy homeostasis by glutamate. Neurochem Int 2012; 61:389-96. [PMID: 22709672 DOI: 10.1016/j.neuint.2012.06.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 06/07/2012] [Accepted: 06/08/2012] [Indexed: 01/24/2023]
Abstract
Bioenergy homeostasis is crucial in maintaining normal cell function and survival and it is thus important to understand cellular mechanisms underlying its regulation. Neurons use a large amount of ATP to maintain membrane potential and synaptic communication, making the brain the most energy consuming organ in the body. Glutamate mediates a large majority of synaptic transmission which is responsible for the expression of neural plasticity and higher brain functions. Most of the energy cost is attributable to the glutamatergic system; under pathological conditions such as stroke and brain ischemia, neural energy depletion is accompanied by a massive release of glutamate. However, the specific cellular processes implicated in glutamate-dependent bioenergy dynamics are not well understood. We find that glutamate induces a rapid and dramatic reduction of ATP levels in neurons, through reduced ATP genesis and elevated consumption. ATP reduction depends on NMDA receptor activity, but is not a result of neuronal firing, gap junction-mediated leaking or intracellular signaling. Similar changes in ATP levels are also induced by synaptic glutamate accumulation following suppression of glutamate transporter activity. Furthermore, the glutamate-induced ATP down-regulation is blocked by the sodium pump inhibitor ouabain, suggesting the sodium pump as the primary energy consumer during glutamate stimulation. These data suggest the important role of glutamate in the control of cellular ATP homeostasis.
Collapse
Affiliation(s)
- Katrina Foo
- Department of Biology, Boston University, 5 Cummington St., Boston, MA 02215, USA
| | | | | |
Collapse
|
33
|
β2-adrenergic receptor and astrocyte glucose metabolism. J Mol Neurosci 2012; 48:456-63. [PMID: 22399228 DOI: 10.1007/s12031-012-9742-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 02/27/2012] [Indexed: 12/19/2022]
Abstract
Astrocyte glucose metabolism functions to maintain brain activity in both normal and stress conditions. Dysregulation of astrocyte glucose metabolism relates to development of neuronal disease, such as multiple sclerosis and Alzheimer's disease. In response to acute stress, beta2-adrenergic receptor is activated and initiates multiple signaling events mediated by Gs, Gi, arrestin, or other effectors depending on specific cellular contexts. In astrocytes, beta2-adrenergic receptor promotes glucose uptake through GLUT1 and accelerates glycogen degradation via coupling to Gs and second messenger cAMP-dependent pathway. Beta2-adrenergic receptor may regulate other steps in astrocyte glucose metabolism, such as lactate production or transduction. Inappropriate regulation of beta2-adrenergic receptor activity can disrupt normal glucose metabolism, and leads to accelerate neuronal disease development. It was demonstrated that the absence of beta2-adrenergic receptor in astrocytes occurred in multiple sclerosis patients, and the increased beta2-adrenergic receptor activity relates to Alzheimer's disease. A clear view of beta2-adrenergic receptor-mediated signaling pathways in regulating astrocyte glucose metabolism could help us to develop neuronal diseases treatment by targeting to the beta2-adrenergic receptor.
Collapse
|
34
|
Jensen J, Rustad PI, Kolnes AJ, Lai YC. The role of skeletal muscle glycogen breakdown for regulation of insulin sensitivity by exercise. Front Physiol 2011; 2:112. [PMID: 22232606 PMCID: PMC3248697 DOI: 10.3389/fphys.2011.00112] [Citation(s) in RCA: 219] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 12/09/2011] [Indexed: 12/12/2022] Open
Abstract
Glycogen is the storage form of carbohydrates in mammals. In humans the majority of glycogen is stored in skeletal muscles (∼500 g) and the liver (∼100 g). Food is supplied in larger meals, but the blood glucose concentration has to be kept within narrow limits to survive and stay healthy. Therefore, the body has to cope with periods of excess carbohydrates and periods without supplementation. Healthy persons remove blood glucose rapidly when glucose is in excess, but insulin-stimulated glucose disposal is reduced in insulin resistant and type 2 diabetic subjects. During a hyperinsulinemic euglycemic clamp, 70-90% of glucose disposal will be stored as muscle glycogen in healthy subjects. The glycogen stores in skeletal muscles are limited because an efficient feedback-mediated inhibition of glycogen synthase prevents accumulation. De novo lipid synthesis can contribute to glucose disposal when glycogen stores are filled. Exercise physiologists normally consider glycogen's main function as energy substrate. Glycogen is the main energy substrate during exercise intensity above 70% of maximal oxygen uptake ([Formula: see text]) and fatigue develops when the glycogen stores are depleted in the active muscles. After exercise, the rate of glycogen synthesis is increased to replete glycogen stores, and blood glucose is the substrate. Indeed insulin-stimulated glucose uptake and glycogen synthesis is elevated after exercise, which, from an evolutional point of view, will favor glycogen repletion and preparation for new "fight or flight" events. In the modern society, the reduced glycogen stores in skeletal muscles after exercise allows carbohydrates to be stored as muscle glycogen and prevents that glucose is channeled to de novo lipid synthesis, which over time will causes ectopic fat accumulation and insulin resistance. The reduction of skeletal muscle glycogen after exercise allows a healthy storage of carbohydrates after meals and prevents development of type 2 diabetes.
Collapse
Affiliation(s)
- Jørgen Jensen
- Department of Physical Performance, Norwegian School of Sport Sciences Oslo, Norway
| | | | | | | |
Collapse
|