1
|
Gyau BB, Deaglio S. A 2A receptor signaling drives cisplatin-mediated hippocampal neurotoxicity and cognitive defects in mice. Purinergic Signal 2023; 19:591-593. [PMID: 36639514 PMCID: PMC10754773 DOI: 10.1007/s11302-023-09919-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 01/05/2023] [Indexed: 01/15/2023] Open
Affiliation(s)
- Benjamin B Gyau
- Laboratory of Functional Genomics, Department of Medical Sciences, University of Turin, 10126, Turin, Italy.
| | - Silvia Deaglio
- Laboratory of Functional Genomics, Department of Medical Sciences, University of Turin, 10126, Turin, Italy
| |
Collapse
|
2
|
Oliveros A, Yoo KH, Rashid MA, Corujo-Ramirez A, Hur B, Sung J, Liu Y, Hawse JR, Choi DS, Boison D, Jang MH. Adenosine A 2A receptor blockade prevents cisplatin-induced impairments in neurogenesis and cognitive function. Proc Natl Acad Sci U S A 2022; 119:e2206415119. [PMID: 35867768 PMCID: PMC9282426 DOI: 10.1073/pnas.2206415119] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 05/23/2022] [Indexed: 11/21/2022] Open
Abstract
Chemotherapy-induced cognitive impairment (CICI) has emerged as a significant medical problem without therapeutic options. Using the platinum-based chemotherapy cisplatin to model CICI, we revealed robust elevations in the adenosine A2A receptor (A2AR) and its downstream effectors, cAMP and CREB, by cisplatin in the adult mouse hippocampus, a critical brain structure for learning and memory. Notably, A2AR inhibition by the Food and Drug Administration-approved A2AR antagonist KW-6002 prevented cisplatin-induced impairments in neural progenitor proliferation and dendrite morphogenesis of adult-born neurons, while improving memory and anxiety-like behavior, without affecting tumor growth or cisplatin's antitumor activity. Collectively, our study identifies A2AR signaling as a key pathway that can be therapeutically targeted to prevent cisplatin-induced cognitive impairments.
Collapse
Affiliation(s)
- Alfredo Oliveros
- Neurologic Surgery, Mayo Clinic, Rochester, MN 55905
- Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854
| | - Ki Hyun Yoo
- Neurologic Surgery, Mayo Clinic, Rochester, MN 55905
- Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854
| | - Mohammad Abdur Rashid
- Neurologic Surgery, Mayo Clinic, Rochester, MN 55905
- Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854
| | | | - Benjamin Hur
- Division of Surgery Research, Department of Surgery, Mayo Clinic, Rochester, MN 55905
| | - Jaeyun Sung
- Division of Surgery Research, Department of Surgery, Mayo Clinic, Rochester, MN 55905
| | - Yuanhang Liu
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN 55905
| | - John R. Hawse
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905
| | - Doo-Sup Choi
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905
| | - Detlev Boison
- Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854
| | - Mi-Hyeon Jang
- Neurologic Surgery, Mayo Clinic, Rochester, MN 55905
- Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905
| |
Collapse
|
3
|
Emerging roles of dysregulated adenosine homeostasis in brain disorders with a specific focus on neurodegenerative diseases. J Biomed Sci 2021; 28:70. [PMID: 34635103 PMCID: PMC8507231 DOI: 10.1186/s12929-021-00766-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/04/2021] [Indexed: 02/07/2023] Open
Abstract
In modern societies, with an increase in the older population, age-related neurodegenerative diseases have progressively become greater socioeconomic burdens. To date, despite the tremendous effort devoted to understanding neurodegenerative diseases in recent decades, treatment to delay disease progression is largely ineffective and is in urgent demand. The development of new strategies targeting these pathological features is a timely topic. It is important to note that most degenerative diseases are associated with the accumulation of specific misfolded proteins, which is facilitated by several common features of neurodegenerative diseases (including poor energy homeostasis and mitochondrial dysfunction). Adenosine is a purine nucleoside and neuromodulator in the brain. It is also an essential component of energy production pathways, cellular metabolism, and gene regulation in brain cells. The levels of intracellular and extracellular adenosine are thus tightly controlled by a handful of proteins (including adenosine metabolic enzymes and transporters) to maintain proper adenosine homeostasis. Notably, disruption of adenosine homeostasis in the brain under various pathophysiological conditions has been documented. In the past two decades, adenosine receptors (particularly A1 and A2A adenosine receptors) have been actively investigated as important drug targets in major degenerative diseases. Unfortunately, except for an A2A antagonist (istradefylline) administered as an adjuvant treatment with levodopa for Parkinson's disease, no effective drug based on adenosine receptors has been developed for neurodegenerative diseases. In this review, we summarize the emerging findings on proteins involved in the control of adenosine homeostasis in the brain and discuss the challenges and future prospects for the development of new therapeutic treatments for neurodegenerative diseases and their associated disorders based on the understanding of adenosine homeostasis.
Collapse
|
4
|
Moreira-de-Sá A, Lourenço VS, Canas PM, Cunha RA. Adenosine A 2A Receptors as Biomarkers of Brain Diseases. Front Neurosci 2021; 15:702581. [PMID: 34335174 PMCID: PMC8322233 DOI: 10.3389/fnins.2021.702581] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/22/2021] [Indexed: 12/12/2022] Open
Abstract
Extracellular adenosine is produced with increased metabolic activity or stress, acting as a paracrine signal of cellular effort. Adenosine receptors are most abundant in the brain, where adenosine acts through inhibitory A1 receptors to decrease activity/noise and through facilitatory A2A receptors (A2AR) to promote plastic changes in physiological conditions. By bolstering glutamate excitotoxicity and neuroinflammation, A2AR also contribute to synaptic and neuronal damage, as heralded by the neuroprotection afforded by the genetic or pharmacological blockade of A2AR in animal models of ischemia, traumatic brain injury, convulsions/epilepsy, repeated stress or Alzheimer's or Parkinson's diseases. A2AR overfunction is not only necessary for the expression of brain damage but is actually sufficient to trigger brain dysfunction in the absence of brain insults or other disease triggers. Furthermore, A2AR overfunction seems to be an early event in the demise of brain diseases, which involves an increased formation of ATP-derived adenosine and an up-regulation of A2AR. This prompts the novel hypothesis that the evaluation of A2AR density in afflicted brain circuits may become an important biomarker of susceptibility and evolution of brain diseases once faithful PET ligands are optimized. Additional relevant biomarkers would be measuring the extracellular ATP and/or adenosine levels with selective dyes, to identify stressed regions in the brain. A2AR display several polymorphisms in humans and preliminary studies have associated different A2AR polymorphisms with altered morphofunctional brain endpoints associated with neuropsychiatric diseases. This further prompts the interest in exploiting A2AR polymorphic analysis as an ancillary biomarker of susceptibility/evolution of brain diseases.
Collapse
Affiliation(s)
- Ana Moreira-de-Sá
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Vanessa S Lourenço
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Paula M Canas
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Rodrigo A Cunha
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| |
Collapse
|
5
|
Atif M, Alsrhani A, Naz F, Imran M, Imran M, Ullah MI, Alameen AAM, Gondal TA, Raza Q. Targeting Adenosine Receptors in Neurological Diseases. Cell Reprogram 2021; 23:57-72. [PMID: 33861641 DOI: 10.1089/cell.2020.0087] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Adenosine plays a significant role in neurotransmission process by controlling the blood pressure, while adenosine triphosphate (ATP) acts as a neuromodulator and neurotransmitter and by activation of P2 receptors, regulates the contractility of the heart. Adenosine signaling is essential in the process of regeneration by regulating proliferation, differentiation, and apoptosis of stem cells. In this review, we have selected neurological disorders (Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, and epilepsy) with clinical trials using antagonists and epigenetic tools targeting adenosine receptor as a therapeutic approach in the treatment of these disorders. Promising results have been reported from many clinical trials. It has been found that higher expression levels of A2A and P2X7 receptors in neurological disorders further complicate the disease condition. Therefore, modulations of these receptors by using antagonists of these receptors or SAM (S-adenosylmethionine) therapy as an epigenetic tool could be useful in reversing the complications of these disorders. Finally, we suggest that modulation of adenosine receptors in neurological disorders can increase the regenerative phase by increasing the rate of proliferation and differentiation in the damaged tissues.
Collapse
Affiliation(s)
- Muhmmad Atif
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka, Saudi Arabia
| | - Abdullah Alsrhani
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka, Saudi Arabia
| | - Farrah Naz
- Department of Microbiology, Government College University, Faisalabad, Pakistan
| | - Muhammad Imran
- University Institute of Diet and Nutritional Sciences, Faculty of Allied Health Sciences, The University of Lahore, Lahore, Pakistan
| | - Muhammad Imran
- Department of Microbiology, University of Health Sciences, Lahore, Pakistan
| | - Muhammad Ikram Ullah
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka, Saudi Arabia
| | - Ayman A M Alameen
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka, Saudi Arabia.,Department of Chemical Pathology, Faculty of Medical Laboratory Sciences, University of Khartoum, Khartoum, Sudan
| | - Tanweer Aslam Gondal
- School of Exercise and Nutrition, Faculty of Health, Deakin University, Victoria, Australia
| | - Qaisar Raza
- Department of Clinical Nutrition, NUR International University, Lahore, Pakistan
| |
Collapse
|
6
|
Temido-Ferreira M, Coelho JE, Pousinha PA, Lopes LV. Novel Players in the Aging Synapse: Impact on Cognition. J Caffeine Adenosine Res 2019; 9:104-127. [PMID: 31559391 PMCID: PMC6761599 DOI: 10.1089/caff.2019.0013] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
While neuronal loss has long been considered as the main contributor to age-related cognitive decline, these alterations are currently attributed to gradual synaptic dysfunction driven by calcium dyshomeostasis and alterations in ionotropic/metabotropic receptors. Given the key role of the hippocampus in encoding, storage, and retrieval of memory, the morpho- and electrophysiological alterations that occur in the major synapse of this network-the glutamatergic-deserve special attention. We guide you through the hippocampal anatomy, circuitry, and function in physiological context and focus on alterations in neuronal morphology, calcium dynamics, and plasticity induced by aging and Alzheimer's disease (AD). We provide state-of-the art knowledge on glutamatergic transmission and discuss implications of these novel players for intervention. A link between regular consumption of caffeine-an adenosine receptor blocker-to decreased risk of AD in humans is well established, while the mechanisms responsible have only now been uncovered. We review compelling evidence from humans and animal models that implicate adenosine A2A receptors (A2AR) upsurge as a crucial mediator of age-related synaptic dysfunction. The relevance of this mechanism in patients was very recently demonstrated in the form of a significant association of the A2AR-encoding gene with hippocampal volume (synaptic loss) in mild cognitive impairment and AD. Novel pathways implicate A2AR in the control of mGluR5-dependent NMDAR activation and subsequent Ca2+ dysfunction upon aging. The nature of this receptor makes it particularly suited for long-term therapies, as an alternative for regulating aberrant mGluR5/NMDAR signaling in aging and disease, without disrupting their crucial constitutive activity.
Collapse
Affiliation(s)
- Mariana Temido-Ferreira
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Joana E. Coelho
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Paula A. Pousinha
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), CNRS UMR7275, Université Côte d'Azur, Valbonne, France
| | - Luísa V. Lopes
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| |
Collapse
|
7
|
Huin V, Dhaenens CM, Homa M, Carvalho K, Buée L, Sablonnière B. Neurogenetics of the Human Adenosine Receptor Genes: Genetic Structures and Involvement in Brain Diseases. J Caffeine Adenosine Res 2019. [DOI: 10.1089/caff.2019.0011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Vincent Huin
- University of Lille, INSERM, CHU Lille, UMR-S 1172-JPArc–Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, Lille, France
- CHU Lille, Institut de Biochimie et Biologie moléculaire, Centre de Biologie Pathologie et Génétique, Lille, France
| | - Claire-Marie Dhaenens
- University of Lille, INSERM, CHU Lille, UMR-S 1172-JPArc–Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, Lille, France
- CHU Lille, Institut de Biochimie et Biologie moléculaire, Centre de Biologie Pathologie et Génétique, Lille, France
| | - Mégane Homa
- University of Lille, INSERM, CHU Lille, UMR-S 1172-JPArc–Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, Lille, France
| | - Kévin Carvalho
- University of Lille, INSERM, CHU Lille, UMR-S 1172-JPArc–Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, Lille, France
| | - Luc Buée
- University of Lille, INSERM, CHU Lille, UMR-S 1172-JPArc–Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, Lille, France
| | - Bernard Sablonnière
- University of Lille, INSERM, CHU Lille, UMR-S 1172-JPArc–Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, Lille, France
- CHU Lille, Institut de Biochimie et Biologie moléculaire, Centre de Biologie Pathologie et Génétique, Lille, France
| |
Collapse
|
8
|
Falconi A, Bonito-Oliva A, Di Bartolomeo M, Massimini M, Fattapposta F, Locuratolo N, Dainese E, Pascale E, Fisone G, D'Addario C. On the Role of Adenosine A2A Receptor Gene Transcriptional Regulation in Parkinson's Disease. Front Neurosci 2019; 13:683. [PMID: 31354407 PMCID: PMC6635589 DOI: 10.3389/fnins.2019.00683] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 06/14/2019] [Indexed: 12/14/2022] Open
Abstract
Adenosine A2A receptors (A2ARs) have attracted considerable attention as an important molecular target for the design of Parkinson's disease (PD) therapeutic compounds. Here, we studied the transcriptional regulation of the A2AR gene in human peripheral blood mononuclear cells (PBMCs) obtained from PD patients and in the striatum of the well-validated, 6-hydroxydopamine (6-OHDA)-induced PD mouse model. We report an increase in A2AR mRNA expression and protein levels in both human cells and mice striata, and in the latter we could also observe a consistent reduction in DNA methylation at gene promoter and an increase in histone H3 acetylation at lysine 9. Of particular relevance in clinical samples, we also observed higher levels in the receptor gene expression in younger subjects, as well as in those with less years from disease onset, and less severe disease according to clinical scores. In conclusion, the present findings provide further evidence of the relevant role of A2AR in PD and, based on the clinical data, highlight its potential role as disease biomarker for PD especially at the initial stages of disease development. Furthermore, our preclinical results also suggest selective epigenetic mechanisms targeting gene promoter as tool for the development of new treatments.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Enrico Dainese
- Faculty of Bioscience, University of Teramo, Teramo, Italy
| | - Esterina Pascale
- Department of Medical-Surgical Sciences and Biotechnologies, Sapienza University, Rome, Italy
| | - Gilberto Fisone
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Claudio D'Addario
- Faculty of Bioscience, University of Teramo, Teramo, Italy.,Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| |
Collapse
|
9
|
Blum D, Chern Y, Domenici MR, Buée L, Lin CY, Rea W, Ferré S, Popoli P. The Role of Adenosine Tone and Adenosine Receptors in Huntington's Disease. J Caffeine Adenosine Res 2018; 8:43-58. [PMID: 30023989 PMCID: PMC6049521 DOI: 10.1089/caff.2018.0006] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Huntington's disease (HD) is a hereditary neurodegenerative disorder caused by a mutation in the IT15 gene that encodes for the huntingtin protein. Mutated hungtingtin, although widely expressed in the brain, predominantly affects striato-pallidal neurons, particularly enriched with adenosine A2A receptors (A2AR), suggesting a possible involvement of adenosine and A2AR is the pathogenesis of HD. In fact, polymorphic variation in the ADORA2A gene influences the age at onset in HD, and A2AR dynamics is altered by mutated huntingtin. Basal levels of adenosine and adenosine receptors are involved in many processes critical for neuronal function and homeostasis, including modulation of synaptic activity and excitotoxicity, the control of neurotrophin levels and functions, and the regulation of protein degradation mechanisms. In the present review, we critically analyze the current literature involving the effect of altered adenosine tone and adenosine receptors in HD and discuss why therapeutics that modulate the adenosine system may represent a novel approach for the treatment of HD.
Collapse
Affiliation(s)
- David Blum
- University of Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc, LabEx DISTALZ, Lille, France
| | - Yijuang Chern
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Maria Rosaria Domenici
- National Center for Drug Research and Evaluation, Istituto Superiore di Sanità, Rome, Italy
| | - Luc Buée
- University of Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc, LabEx DISTALZ, Lille, France
| | - Chien-Yu Lin
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - William Rea
- Integrative Neurobiology Section, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland
| | - Sergi Ferré
- Integrative Neurobiology Section, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland
| | - Patrizia Popoli
- National Center for Drug Research and Evaluation, Istituto Superiore di Sanità, Rome, Italy
| |
Collapse
|
10
|
Ferrer I. Sisyphus in Neverland. J Alzheimers Dis 2018; 62:1023-1047. [PMID: 29154280 PMCID: PMC5870014 DOI: 10.3233/jad-170609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2017] [Indexed: 11/24/2022]
Abstract
The study of life and living organisms and the way in which these interact and organize to form social communities have been central to my career. I have been fascinated by biology, neurology, and neuropathology, but also by history, sociology, and art. Certain current historical, political, and social events, some occurring proximally but others affecting people in apparently distant places, have had an impact on me. Epicurus, Seneca, and Camus shared their philosophical positions which I learned from. Many scientists from various disciplines have been exciting sources of knowledge as well. I have created a world of hypothesis and experiments but I have also got carried away by serendipity following unexpected observations. It has not been an easy path; errors and wanderings are not uncommon, and opponents close to home much more abundant than one might imagine. Ambition, imagination, resilience, and endurance have been useful in moving ahead in response to setbacks. In the end, I have enjoyed my dedication to science and I am grateful to have glimpsed beauty in it. These are brief memories of a Spanish neuropathologist born and raised in Barcelona, EU.
Collapse
Affiliation(s)
- Isidro Ferrer
- Department of Pathology and Experimental Therapeutics, University of Barcelona; Service of Pathological Anatomy, Bellvitge University Hospital; CIBERNED; Hospitalet de Llobregat, Barcelona, Spain
| |
Collapse
|
11
|
Cunha RA. How does adenosine control neuronal dysfunction and neurodegeneration? J Neurochem 2016; 139:1019-1055. [PMID: 27365148 DOI: 10.1111/jnc.13724] [Citation(s) in RCA: 301] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/23/2016] [Accepted: 06/23/2016] [Indexed: 12/11/2022]
Abstract
The adenosine modulation system mostly operates through inhibitory A1 (A1 R) and facilitatory A2A receptors (A2A R) in the brain. The activity-dependent release of adenosine acts as a brake of excitatory transmission through A1 R, which are enriched in glutamatergic terminals. Adenosine sharpens salience of information encoding in neuronal circuits: high-frequency stimulation triggers ATP release in the 'activated' synapse, which is locally converted by ecto-nucleotidases into adenosine to selectively activate A2A R; A2A R switch off A1 R and CB1 receptors, bolster glutamate release and NMDA receptors to assist increasing synaptic plasticity in the 'activated' synapse; the parallel engagement of the astrocytic syncytium releases adenosine further inhibiting neighboring synapses, thus sharpening the encoded plastic change. Brain insults trigger a large outflow of adenosine and ATP, as a danger signal. A1 R are a hurdle for damage initiation, but they desensitize upon prolonged activation. However, if the insult is near-threshold and/or of short-duration, A1 R trigger preconditioning, which may limit the spread of damage. Brain insults also up-regulate A2A R, probably to bolster adaptive changes, but this heightens brain damage since A2A R blockade affords neuroprotection in models of epilepsy, depression, Alzheimer's, or Parkinson's disease. This initially involves a control of synaptotoxicity by neuronal A2A R, whereas astrocytic and microglia A2A R might control the spread of damage. The A2A R signaling mechanisms are largely unknown since A2A R are pleiotropic, coupling to different G proteins and non-canonical pathways to control the viability of glutamatergic synapses, neuroinflammation, mitochondria function, and cytoskeleton dynamics. Thus, simultaneously bolstering A1 R preconditioning and preventing excessive A2A R function might afford maximal neuroprotection. The main physiological role of the adenosine modulation system is to sharp the salience of information encoding through a combined action of adenosine A2A receptors (A2A R) in the synapse undergoing an alteration of synaptic efficiency with an increased inhibitory action of A1 R in all surrounding synapses. Brain insults trigger an up-regulation of A2A R in an attempt to bolster adaptive plasticity together with adenosine release and A1 R desensitization; this favors synaptotocity (increased A2A R) and decreases the hurdle to undergo degeneration (decreased A1 R). Maximal neuroprotection is expected to result from a combined A2A R blockade and increased A1 R activation. This article is part of a mini review series: "Synaptic Function and Dysfunction in Brain Diseases".
Collapse
Affiliation(s)
- Rodrigo A Cunha
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,FMUC-Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| |
Collapse
|
12
|
Reynolds JP, Miller-Delaney SFC, Jimenez-Mateos EM, Sano T, McKiernan RC, Simon RP, Henshall DC. Transcriptional Response of Polycomb Group Genes to Status Epilepticus in Mice is Modified by Prior Exposure to Epileptic Preconditioning. Front Neurol 2015; 6:46. [PMID: 25806020 PMCID: PMC4354380 DOI: 10.3389/fneur.2015.00046] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Accepted: 02/23/2015] [Indexed: 12/23/2022] Open
Abstract
Exposure of the brain to brief, non-harmful seizures can activate protective mechanisms that temporarily generate a damage-refractory state. This process, termed epileptic tolerance, is associated with large-scale down-regulation of gene expression. Polycomb group (PcG) proteins are master controllers of gene silencing during development that are re-activated by injury to the brain. Here, we explored the transcriptional response of genes associated with polycomb repressive complex (PRC) 1 (Ring1A, Ring1B, and Bmi1) and PRC2 (Ezh1, Ezh2, and Suz12), as well as additional transcriptional regulators Sirt1, Yy1, and Yy2, in a mouse model of status epilepticus (SE). Findings were contrasted to changes after SE in mice previously given brief seizures to evoke tolerance. Real-time quantitative PCR showed SE prompted an early (1 h) increase in expression of several genes in PRC1 and PRC2 in the hippocampus, followed by down-regulation of many of the same genes at later times points (4, 8, and 24 h). Spatio-temporal differences were found among PRC2 genes in epileptic tolerance, including increased expression of Ezh2, Suz12, and Yy2 relative to the normal injury response to SE. In contrast, PRC1 complex genes including Ring 1B and Bmi1 displayed differential down-regulation in epileptic tolerance. The present study characterizes PcG gene expression following SE and shows prior seizure exposure produces select changes to PRC1 and PRC2 composition that may influence differential gene expression in epileptic tolerance.
Collapse
Affiliation(s)
- James P Reynolds
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland , Dublin , Ireland
| | | | - Eva M Jimenez-Mateos
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland , Dublin , Ireland
| | - Takanori Sano
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland , Dublin , Ireland ; Department of Neurosurgery, Mie University School of Medicine , Tsu, Mie , Japan
| | - Ross C McKiernan
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland , Dublin , Ireland
| | | | - David C Henshall
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland , Dublin , Ireland
| |
Collapse
|
13
|
Villar-Menéndez I, Nuñez F, Díaz-Sánchez S, Albasanz JL, Taura J, Fernández-Dueñas V, Ferrer I, Martín M, Ciruela F, Barrachina M. Striatal adenosine A2A receptor expression is controlled by S-adenosyl-L-methionine-mediated methylation. Purinergic Signal 2014; 10:523-8. [PMID: 24943396 DOI: 10.1007/s11302-014-9417-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 06/05/2014] [Indexed: 12/01/2022] Open
Abstract
Adenosine A2A receptor (A2AR) is a G protein-coupled receptor enriched in the striatum for which an increased expression has been demonstrated in certain neurological diseases. Interestingly, previous in vitro studies demonstrated that A2AR expression levels are reduced after treatment with S-adenosyl-L-methionine (SAM), a methyl donor molecule involved in the methylation of important biological structures such as DNA, proteins, and lipids. However, the in vivo effects of SAM treatment on A2AR expression are still obscure. Here, we demonstrated that 2 weeks of SAM treatment produced a significant reduction in the rat striatal A2AR messenger RNA (mRNA) and protein content as well as A2AR-mediated signaling. Furthermore, when the content of 5-methylcytosine levels in the 5'UTR region of ADORA2A was analyzed, this was significantly increased in the striatum of SAM-treated animals; thus, an unambiguous correlation between SAM-mediated methylation and striatal A2AR expression could be established. Overall, we concluded that striatal A2AR functionality can be controlled by SAM treatment, an issue that might be relevant for the management of these neurological conditions that course with increased A2AR expression.
Collapse
Affiliation(s)
- Izaskun Villar-Menéndez
- Institute of Neuropathology, Bellvitge Biomedical Research Institute (IDIBELL), Bellvitge University Hospital-ICS, Av. Gran Via de L'Hospitalet 199, L'Hospitalet de Llobregat, 08908, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Increased striatal adenosine A2A receptor levels is an early event in Parkinson's disease-related pathology and it is potentially regulated by miR-34b. Neurobiol Dis 2014; 69:206-14. [PMID: 24892887 DOI: 10.1016/j.nbd.2014.05.030] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 05/01/2014] [Accepted: 05/22/2014] [Indexed: 12/20/2022] Open
Abstract
Adenosine A2A receptor (A2AR) is a G-protein coupled receptor that stimulates adenylyl cyclase activity. In the brain, A2ARs are found highly enriched in striatal GABAergic medium spiny neurons, related to the control of voluntary movement. Pharmacological modulation of A2ARs is particularly useful in Parkinson's disease (PD) due to their property of antagonizing dopamine D2 receptor activity. Increases in A2AR levels have been described in PD patients showing an important loss of dopaminergic denervation markers, but no data have been reported about A2AR levels in incidental PD brains. In the present report, we show that increased A2ARs protein levels were also detected in the putamen of incidental PD cases (Braak PD stages 1-2) with respect to age-matched controls. By contrast, A2ARs mRNA levels remained unchanged, suggesting that posttranslational mechanisms could be involved in the regulation of A2ARs. It has been described how miR-34b/c downregulation is an early event in PD cases. We found that miR-34b levels are also significantly reduced in the putamen of incidental PD cases and along disease progression. Given that 3'UTR of A2AR contains a predicted target site for miR-34b, the potential role of this miRNA in protein A2AR levels was assessed. In vitro studies revealed that endogenous A2AR protein levels increased when miR-34b function was blocked using a specific anti-miR-34b. Moreover, using a luciferase reporter assay with point mutations in a miR-34b predicted binding site within the 3'UTR region of A2AR mRNA abolished the effect of the miRNA using a miR-34b mimic. In addition, we showed a reduced percentage of DNA methylation in the 5'UTR region of ADORA2A in advanced PD cases. Overall, these findings reveal that increased A2AR protein levels occur in asymptomatic PD patients and provide new insights into the molecular mechanisms underlying A2AR expression levels along the progression of this neurodegenerative disease.
Collapse
|
15
|
Villar-Menéndez I, Díaz-Sánchez S, Blanch M, Albasanz JL, Pereira-Veiga T, Monje A, Planchat LM, Ferrer I, Martín M, Barrachina M. Reduced striatal adenosine A2A receptor levels define a molecular subgroup in schizophrenia. J Psychiatr Res 2014; 51:49-59. [PMID: 24433848 DOI: 10.1016/j.jpsychires.2013.12.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 11/13/2013] [Accepted: 12/20/2013] [Indexed: 01/02/2023]
Abstract
Schizophrenia (SZ) is a mental disorder of unknown origin. Some scientific evidence seems to indicate that SZ is not a single disease entity, since there are patient groups with clear symptomatic, course and biomarker differences. SZ is characterized by a hyperdopaminergic state related to high dopamine D2 receptor activity. It has also been proposed that there is a hypoadenosynergic state. Adenosine is a nucleoside widely distributed in the organism with neuromodulative and neuroprotective activity in the central nervous system. In the brain, the most abundant adenosine receptors are A1R and A2AR. In the present report, we characterize the presence of both receptors in human postmortem putamens of patients suffering SZ with real time TaqMan PCR, western blotting and radioligand binding assay. We show that A1R levels remain unchanged with respect to age-matched controls, whereas nearly fifty percent of patients have reduced A2AR, at the transcriptional and translational levels. Moreover, we describe how DNA methylation plays a role in the pathological A2AR levels with the bisulfite-sequencing technique. In fact, an increase in 5-methylcytosine percentage in the 5' UTR region of ADORA2A was found in those SZ patients with reduced A2AR levels. Interestingly, there was a relationship between the A2A/β-actin ratio and motor disturbances as assessed with some items of the PANSS, AIMS and SAS scales. Therefore, there may be a subgroup of SZ patients with reduced striatal A2AR levels accompanied by an altered motor phenotype.
Collapse
Affiliation(s)
- Izaskun Villar-Menéndez
- Institute of Neuropathology, Bellvitge University Hospital-ICS, [Bellvitge Biomedical Research Institute-] IDIBELL, L'Hospitalet de Llobregat, Spain
| | - Sara Díaz-Sánchez
- Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Ciencia y Tecnologías Químicas, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, Ciudad Real, Spain; Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Medicina de Ciudad Real, CRIB, Universidad de Castilla-La Mancha, Ciudad Real, Spain
| | - Marta Blanch
- Institute of Neuropathology, Bellvitge University Hospital-ICS, [Bellvitge Biomedical Research Institute-] IDIBELL, L'Hospitalet de Llobregat, Spain
| | - José Luis Albasanz
- Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Ciencia y Tecnologías Químicas, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, Ciudad Real, Spain; Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Medicina de Ciudad Real, CRIB, Universidad de Castilla-La Mancha, Ciudad Real, Spain
| | - Thais Pereira-Veiga
- Institute of Neuropathology, Bellvitge University Hospital-ICS, [Bellvitge Biomedical Research Institute-] IDIBELL, L'Hospitalet de Llobregat, Spain
| | - Alfonso Monje
- Banc de Teixits Neurològics-Parc Sanitari Sant Joan de Déu, CIBERSAM, Sant Boi de Llobregat, Spain
| | - Luis Maria Planchat
- Banc de Teixits Neurològics-Parc Sanitari Sant Joan de Déu, CIBERSAM, Sant Boi de Llobregat, Spain
| | - Isidre Ferrer
- Institute of Neuropathology, Bellvitge University Hospital-ICS, [Bellvitge Biomedical Research Institute-] IDIBELL, L'Hospitalet de Llobregat, Spain; Departament de Patologia i Terapèutica Experimental, Universitat de Barcelona, L'Hospitalet de Llobregat, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, CIBERNED, Spain
| | - Mairena Martín
- Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Ciencia y Tecnologías Químicas, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, Ciudad Real, Spain; Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Medicina de Ciudad Real, CRIB, Universidad de Castilla-La Mancha, Ciudad Real, Spain
| | - Marta Barrachina
- Institute of Neuropathology, Bellvitge University Hospital-ICS, [Bellvitge Biomedical Research Institute-] IDIBELL, L'Hospitalet de Llobregat, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, CIBERNED, Spain.
| |
Collapse
|
16
|
Lee CF, Chern Y. Adenosine receptors and Huntington's disease. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2014; 119:195-232. [PMID: 25175968 DOI: 10.1016/b978-0-12-801022-8.00010-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Adenosine regulates important pathophysiological functions via four distinct adenosine receptor subtypes (A1, A2A, A2B, and A3). The A1 and A2A adenosine receptors (A1R and A2AR) are major targets of caffeine and have been extensively investigated. Huntington's disease (HD) is a dominant neurodegenerative disease caused by an abnormal CAG expansion in the Huntingtin gene. Since the first genetic HD model was created almost two decades ago, tremendous progress regarding the function of the adenosine receptors in HD has been made. Chronic intake of caffeine was recently shown to be positively associated with the disease onset of HD. Moreover, genetic polymorphism of A2AR is believed to impact the age of onset. Given the importance of adenosine receptors as drug targets for human diseases, this review highlights the recent findings that delineate the roles of adenosine receptors in HD and discusses their potential for serving as drug targets and/or biomarkers for HD. Adenosine is a purine nucleoside that regulates important physiological functions via four different adenosine receptors (A1, A2A, A2B, and A3). These adenosine receptors have seven transmembrane domains and belong to the G protein-coupled receptor family. The functions of the A1 adenosine receptor (A1R) and A2A adenosine receptor (A2AR) have been investigated relative to HD. In this review, we summarize the recent findings regarding the role of adenosine receptors in HD and discuss the potential application of adenosine receptors as drug targets and biomarkers for HD.
Collapse
Affiliation(s)
- Chien-fei Lee
- Division of Neuroscience, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yijuang Chern
- Division of Neuroscience, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.
| |
Collapse
|
17
|
Gao K, Wang CR, Jiang F, Wong AYK, Su N, Jiang JH, Chai RC, Vatcher G, Teng J, Chen J, Jiang YW, Yu ACH. Traumatic scratch injury in astrocytes triggers calcium influx to activate the JNK/c-Jun/AP-1 pathway and switch on GFAP expression. Glia 2013; 61:2063-77. [PMID: 24123203 DOI: 10.1002/glia.22577] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 08/11/2013] [Accepted: 08/21/2013] [Indexed: 01/25/2023]
Abstract
Astrocyte activation is a hallmark of central nervous system injuries resulting in glial scar formation (astrogliosis). The activation of astrocytes involves metabolic and morphological changes with complex underlying mechanisms, which should be defined to provide targets for astrogliosis intervention. Astrogliosis is usually accompanied by an upregulation of glial fibrillary acidic protein (GFAP). Using an in vitro scratch injury model, we scratched primary cultures of cerebral cortical astrocytes and observed an influx of calcium in the form of waves spreading away from the wound through gap junctions. Using the calcium blocker BAPTA-AM and the JNK inhibitor SP600125, we demonstrated that the calcium wave triggered the activation of JNK, which then phosphorylated the transcription factor c-Jun to facilitate the binding of AP-1 to the GFAP gene promoter to switch on GFAP upregulation. Blocking calcium mobilization with BAPTA-AM in an in vivo stab wound model reduced GFAP expression and glial scar formation, showing that the calcium signal, and the subsequent regulation of downstream signaling molecules, plays an essential role in brain injury response. Our findings demonstrated that traumatic scratch injury to astrocytes triggered a calcium influx from the extracellular compartment and activated the JNK/c-Jun/AP-1 pathway to switch on GFAP expression, identifying a previously unreported signaling cascade that is important in astrogliosis and the physiological response following brain injury.
Collapse
Affiliation(s)
- Kai Gao
- Neuroscience Research Institute, Key Laboratory for Neuroscience (Ministry of Education), Key Laboratory for Neuroscience (National Health and Family Planning Commission), Department of Neurobiology, School of Basic Medical Sciences, Health Science Center, Peking University, Beijing, China
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Villar-Menéndez I, Blanch M, Tyebji S, Pereira-Veiga T, Albasanz JL, Martín M, Ferrer I, Pérez-Navarro E, Barrachina M. Increased 5-Methylcytosine and Decreased 5-Hydroxymethylcytosine Levels are Associated with Reduced Striatal A2AR Levels in Huntington’s Disease. Neuromolecular Med 2013; 15:295-309. [DOI: 10.1007/s12017-013-8219-0] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 01/24/2013] [Indexed: 12/22/2022]
|
19
|
Thakar A, Sylar E, Flynn FW. Activation of tachykinin, neurokinin 3 receptors affects chromatin structure and gene expression by means of histone acetylation. Peptides 2012; 38:282-90. [PMID: 22985858 PMCID: PMC3513652 DOI: 10.1016/j.peptides.2012.09.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 09/06/2012] [Accepted: 09/06/2012] [Indexed: 01/17/2023]
Abstract
The tachykinin, neurokinin 3 receptor (NK3R) is a g-protein coupled receptor that is broadly distributed in the nervous system and exerts its diverse physiological actions through multiple signaling pathways. Despite the role of the receptor system in a range of biological functions, the effects of NK3R activation on chromatin dynamics and gene expression have received limited attention. The present work determined the effects of senktide, a selective NK3R agonist, on chromatin organization, acetylation, and gene expression, using qRT-PCR, in a hypothalamic cell line (CLU 209) that expresses the NK3R. Senktide (1 nM, 10nM) caused a relaxation of chromatin, an increase in global acetylation of histone H3 and H4, and an increase in the expression of a common set of genes involved in cell signaling, cell growth, and synaptic plasticity. Pretreatment with histone acetyltransferase (HAT) inhibitor (garcinol and 2-methylene y-butylactone), that inhibits p300, p300/CREB binding protein (CBP) associated factor (PCAF), and GCN 5, prevented the senktide-induced increase in expression of most, but not all, of the genes upregulated in response to 1 nM and 10nM senktide. Treatment with 100 nM had the opposite effect: a reduction in chromatin relaxation and decreased acetylation. The expression of four genes was significantly decreased and the HAT inhibitor had a limited effect in blocking the upregulation of genes in response to 100 nM senktide. Activation of the NK3R appears to recruit multiple pathways, including acetylation, and possibly histone deactylases, histone methylases, or DNA methylases to affect chromatin structure and gene expression.
Collapse
Affiliation(s)
- Amit Thakar
- Graduate Neuroscience Program and Department of Zoology and Physiology University of Wyoming Laramie, WY 82072, United States
| | | | | |
Collapse
|
20
|
Perisic T, Holsboer F, Rein T, Zschocke J. The CpG island shore of the GLT-1 gene acts as a methylation-sensitive enhancer. Glia 2012; 60:1345-55. [PMID: 22593010 DOI: 10.1002/glia.22353] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 04/18/2012] [Indexed: 12/25/2022]
Abstract
Astrocytic lineage commitment and brain region-dependent specialization of glia are partly ascribed to epigenetic processes. Clearance of glutamate is an essential task, which astrocytes assume in a temporal-spatial fashion by distinct glutamate transporter expression. Glutamate transporter subtype 1 (GLT-1) is predominant in cortex (CTX), while it plays an inferior role in cerebellum (CER). Here, we set out to identify regulatory elements that could account for the differences in brain region-specific activity as well as response to dexamethasone (DEX) or epigenetic factors. We found a distal promoter element at the shore of the CpG island exhibiting enhancer function in response to DEX in reporter gene assays. This shore region showed slight enrichment in repressive trimethyl-histone H3 (Lys27) and under-representation of acetyl-histone H4 (H4ac) marks in DEX nonresponsive CER astrocytes as determined by chromatin immunoprecipitation. In addition, CpG sites of the shore region displayed higher methylation in CER than in CTX cells. Targeted in vitro methylation of CpG sites within the shore abrogated the stimulatory effects of DEX. Interestingly, the shore was characterized by a pronounced epigenetic plasticity in CTX cells since DEX exposure elicited an increase of H4ac in CTX in comparison to DEX nonresponsive CER. The transcriptional activity of this region was also affected by histone deacetylase inhibitors in a methylation- and brain region-dependent manner. Together, our study highlights the impact of an epigenetically adaptive DNA element of the GLT-1 promoter being decisive for brain region-specific activity and reactivity.
Collapse
Affiliation(s)
- Tatjana Perisic
- Chaperone Research Group, Max Planck Institute of Psychiatry, Munich, Germany
| | | | | | | |
Collapse
|
21
|
Straccia M, Gresa-Arribas N, Dentesano G, Ejarque-Ortiz A, Tusell JM, Serratosa J, Solà C, Saura J. Pro-inflammatory gene expression and neurotoxic effects of activated microglia are attenuated by absence of CCAAT/enhancer binding protein β. J Neuroinflammation 2011; 8:156. [PMID: 22074460 PMCID: PMC3223504 DOI: 10.1186/1742-2094-8-156] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 11/10/2011] [Indexed: 11/21/2022] Open
Abstract
Background Microglia and astrocytes respond to homeostatic disturbances with profound changes of gene expression. This response, known as glial activation or neuroinflammation, can be detrimental to the surrounding tissue. The transcription factor CCAAT/enhancer binding protein β (C/EBPβ) is an important regulator of gene expression in inflammation but little is known about its involvement in glial activation. To explore the functional role of C/EBPβ in glial activation we have analyzed pro-inflammatory gene expression and neurotoxicity in murine wild type and C/EBPβ-null glial cultures. Methods Due to fertility and mortality problems associated with the C/EBPβ-null genotype we developed a protocol to prepare mixed glial cultures from cerebral cortex of a single mouse embryo with high yield. Wild-type and C/EBPβ-null glial cultures were compared in terms of total cell density by Hoechst-33258 staining; microglial content by CD11b immunocytochemistry; astroglial content by GFAP western blot; gene expression by quantitative real-time PCR, western blot, immunocytochemistry and Griess reaction; and microglial neurotoxicity by estimating MAP2 content in neuronal/microglial cocultures. C/EBPβ DNA binding activity was evaluated by electrophoretic mobility shift assay and quantitative chromatin immunoprecipitation. Results C/EBPβ mRNA and protein levels, as well as DNA binding, were increased in glial cultures by treatment with lipopolysaccharide (LPS) or LPS + interferon γ (IFNγ). Quantitative chromatin immunoprecipitation showed binding of C/EBPβ to pro-inflammatory gene promoters in glial activation in a stimulus- and gene-dependent manner. In agreement with these results, LPS and LPS+IFNγ induced different transcriptional patterns between pro-inflammatory cytokines and NO synthase-2 genes. Furthermore, the expressions of IL-1β and NO synthase-2, and consequent NO production, were reduced in the absence of C/EBPβ. In addition, neurotoxicity elicited by LPS+IFNγ-treated microglia co-cultured with neurons was completely abolished by the absence of C/EBPβ in microglia. Conclusions These findings show involvement of C/EBPβ in the regulation of pro-inflammatory gene expression in glial activation, and demonstrate for the first time a key role for C/EBPβ in the induction of neurotoxic effects by activated microglia.
Collapse
Affiliation(s)
- Marco Straccia
- Biochemistry and Molecular Biology Unit, School of Medicine, University of Barcelona, IDIBAPS, Barcelona, Spain
| | | | | | | | | | | | | | | |
Collapse
|