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Tan AYS, Tippett LJ, Turner CP, Swanson MEV, Park TIH, Curtis MA, Faull RLM, Dragunow M, Singh-Bains MK. Microglial proliferation and astrocytic protein alterations in the human Huntington's disease cortex. Neurobiol Dis 2024; 198:106554. [PMID: 38844243 DOI: 10.1016/j.nbd.2024.106554] [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: 03/20/2024] [Revised: 05/28/2024] [Accepted: 06/03/2024] [Indexed: 06/14/2024] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder that severely affects the basal ganglia and regions of the cerebral cortex. While astrocytosis and microgliosis both contribute to basal ganglia pathology, the contribution of gliosis and potential factors driving glial activity in the human HD cerebral cortex is less understood. Our study aims to identify nuanced indicators of gliosis in HD which is challenging to identify in the severely degenerated basal ganglia, by investigating the middle temporal gyrus (MTG), a cortical region previously documented to demonstrate milder neuronal loss. Immunohistochemistry was conducted on MTG paraffin-embedded tissue microarrays (TMAs) comprising 29 HD and 35 neurologically normal cases to compare the immunoreactivity patterns of key astrocytic proteins (glial fibrillary acidic protein, GFAP; inwardly rectifying potassium channel 4.1, Kir4.1; glutamate transporter-1, GLT-1; aquaporin-4, AQP4), key microglial proteins (ionised calcium-binding adapter molecule-1, IBA-1; human leukocyte antigen (HLA)-DR; transmembrane protein 119, TMEM119; purinergic receptor P2RY12, P2RY12), and indicators of proliferation (Ki-67; proliferative cell nuclear antigen, PCNA). Our findings demonstrate an upregulation of GFAP+ protein expression attributed to the presence of more GFAP+ expressing cells in HD, which correlated with greater cortical mutant huntingtin (mHTT) deposition. In contrast, Kir4.1, GLT-1, and AQP4 immunoreactivity levels were unchanged in HD. We also demonstrate an increased number of IBA-1+ and TMEM119+ microglia with somal enlargement. IBA-1+, TMEM119+, and P2RY12+ reactive microglia immunophenotypes were also identified in HD, evidenced by the presence of rod-shaped, hypertrophic, and dystrophic microglia. In HD cases, IBA-1+ cells contained either Ki-67 or PCNA, whereas GFAP+ astrocytes were devoid of proliferative nuclei. These findings suggest cortical microgliosis may be driven by proliferation in HD, supporting the hypothesis of microglial proliferation as a feature of HD pathophysiology. In contrast, astrocytes in HD demonstrate an altered GFAP expression profile that is associated with the degree of mHTT deposition.
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Affiliation(s)
- Adelie Y S Tan
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; Department of Anatomy and Medical Imaging, University of Auckland, Auckland 1023, New Zealand
| | - Lynette J Tippett
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; School of Psychology, University of Auckland, Auckland 1023, New Zealand
| | - Clinton P Turner
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; Department of Anatomical Pathology, LabPlus, Auckland City Hospital, Auckland 1023, New Zealand
| | - Molly E V Swanson
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; School of Biological Sciences, University of Auckland, Auckland 1023, New Zealand
| | - Thomas I H Park
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; Department of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland 1023, New Zealand
| | - Maurice A Curtis
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; Department of Anatomy and Medical Imaging, University of Auckland, Auckland 1023, New Zealand
| | - Richard L M Faull
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; Department of Anatomy and Medical Imaging, University of Auckland, Auckland 1023, New Zealand
| | - Mike Dragunow
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; Department of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland 1023, New Zealand.
| | - Malvindar K Singh-Bains
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; Department of Anatomy and Medical Imaging, University of Auckland, Auckland 1023, New Zealand.
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Field SE, Curle AJ, Barker RA. Inflammation and Huntington's disease - a neglected therapeutic target? Expert Opin Investig Drugs 2024; 33:451-467. [PMID: 38758356 DOI: 10.1080/13543784.2024.2348738] [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: 12/19/2023] [Accepted: 04/24/2024] [Indexed: 05/18/2024]
Abstract
INTRODUCTION Huntington's Disease (HD) is a genetic neurodegenerative disease for which there is currently no disease-modifying treatment. One of several underlying mechanisms proposed to be involved in HD pathogenesis is inflammation; there is now accumulating evidence that the immune system may play an integral role in disease pathology and progression. As such, modulation of the immune system could be a potential therapeutic target for HD. AREAS COVERED To date, the number of trials targeting immune aspects of HD has been limited. However, targeting it, may have great advantages over other therapeutic areas, given that many drugs already exist that have actions in this system coupled to the fact that inflammation can be measured both peripherally and, to some extent, centrally using CSF and PET imaging. In this review, we look at evidence that the immune system and the newly emerging area of the microbiome are altered in HD patients, and then present and discuss clinical trials that have targeted different parts of the immune system. EXPERT OPINION We then conclude by discussing how this field might develop going forward, focusing on the role of imaging and other biomarkers to monitor central immune activation and response to novel treatments in HD.
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Affiliation(s)
- Sophie E Field
- Department of Clinical Neurosciences, John van Geest Centre for Brain Repair, and MRC-WT Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Annabel J Curle
- Department of Clinical Neurosciences, John van Geest Centre for Brain Repair, and MRC-WT Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Roger A Barker
- Department of Clinical Neurosciences, John van Geest Centre for Brain Repair, and MRC-WT Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
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Bullock TA, Galpayage Dona KNU, Hale JF, Morales P, Jagerovic N, Andrews AM, Ramirez SH. Activation of CB2R by synthetic CB2R agonist, PM289, improves brain endothelial barrier properties, decreases inflammatory response and enhances endothelial repair. NEUROIMMUNE PHARMACOLOGY AND THERAPEUTICS 2023; 2:387-400. [PMID: 38116176 PMCID: PMC10726734 DOI: 10.1515/nipt-2023-0016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 09/30/2023] [Indexed: 12/21/2023]
Abstract
The Cannabinoid 2 Receptor (CB2R) has been found to provide immunological modulation in different cell types. More recently, detection of CB2R in the cerebral endothelium suggests a possible role in the resolution of inflammation at the level of the blood-brain-barrier (BBB). Here, the notion that CB2R upregulation in brain endothelial cells could be exploited to promote vascular protection and BBB integrity was evaluated. Targeting and activation of CB2R was accomplished by a novel and highly specific chromenopyrazole based CB2R agonist, PM289. This study demonstrates that CB2R upregulation is induced as early as 8 h in the cortical vasculature in an experimental mouse model of TBI. Unlike CB2R, CB1R was marginally detected and not significantly induced. In the human brain endothelial cell line, hCMEC/D3 cells, similar induction of CB2R was observed upon stimulation with TNFα. Analysis of transendothelial electrical resistance shows that PM289 markedly prevented the barrier-leakiness induced by TNFα. The BBB is also responsible for maintaining an immunological barrier. The five-fold increase in ICAM1 expression in stimulated endothelial cells was significantly diminished due to CB2R activation. Utilizing wounding assays, results showed that wound repair could be accomplished in nearly half the time when the novel CB2R agonist is present compared to the untreated control. Lastly, mechanistically, the effects of CB2R may be explained by the observed inhibition of the p65 NFκB subunit. Overall, these studies support the notion that targeting and activating CB2R in the brain vasculature could aid in BBB and vascular protection in the context of neuroinflammation.
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Affiliation(s)
- Trent A. Bullock
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
- Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | | | - Jonathan F. Hale
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Paula Morales
- Medicinal Chemistry Institute, Spanish National Research Council, Madrid, Spain
| | - Nadine Jagerovic
- Medicinal Chemistry Institute, Spanish National Research Council, Madrid, Spain
| | - Allison M. Andrews
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
- Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Servio H. Ramirez
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
- Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
- Shriner’s Hospital for Children, Philadelphia, PA, USA
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4
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Grabon W, Bodennec J, Rheims S, Belmeguenai A, Bezin L. Update on the controversial identity of cells expressing cnr2 gene in the nervous system. CNS Neurosci Ther 2023; 29:760-770. [PMID: 36604187 PMCID: PMC9928557 DOI: 10.1111/cns.13977] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 07/29/2022] [Accepted: 08/25/2022] [Indexed: 01/07/2023] Open
Abstract
The function of cannabinoid receptor type 2 (CB2R), mainly expressed by leukocytes, has long been limited to its peripheral immunomodulatory role. However, the use of CB2R-specific ligands and the availability of CB2R-Knock Out mice revealed that it could play a functional role in the CNS not only under physiological but also under pathological conditions. A direct effect on the nervous system emerged when CB2R mRNA was detected in neural tissues. However, accurate mapping of CB2R protein expression in the nervous system is still lacking, partly because of the lack of specificity of antibodies available. This review examines the regions and cells of the nervous system where CB2R protein is most likely present by cross-referencing mRNA and protein data published to date. Of the many antibodies developed to target CB2R, only a few have partially passed specificity tests and detected CB2R in the CNS. Efforts must be continued to support the development of more specific and better validated antibodies in each of the species in which CB2R protein is sought or needs to be quantified.
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Affiliation(s)
- Wanda Grabon
- Lyon Neuroscience Research CenterTIGER TeamBronFrance,Lyon 1 UniversityCNRS UMR 5292, Inserm U1028VilleurbanneFrance,Epilepsy Institute IDEEBronFrance
| | - Jacques Bodennec
- Lyon Neuroscience Research CenterTIGER TeamBronFrance,Lyon 1 UniversityCNRS UMR 5292, Inserm U1028VilleurbanneFrance,Epilepsy Institute IDEEBronFrance
| | - Sylvain Rheims
- Lyon Neuroscience Research CenterTIGER TeamBronFrance,Lyon 1 UniversityCNRS UMR 5292, Inserm U1028VilleurbanneFrance,Epilepsy Institute IDEEBronFrance
| | - Amor Belmeguenai
- Lyon Neuroscience Research CenterTIGER TeamBronFrance,Lyon 1 UniversityCNRS UMR 5292, Inserm U1028VilleurbanneFrance,Epilepsy Institute IDEEBronFrance
| | - Laurent Bezin
- Lyon Neuroscience Research CenterTIGER TeamBronFrance,Lyon 1 UniversityCNRS UMR 5292, Inserm U1028VilleurbanneFrance,Epilepsy Institute IDEEBronFrance
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Li S, Huang Y, Yu L, Ji X, Wu J. Impact of the Cannabinoid System in Alzheimer's Disease. Curr Neuropharmacol 2023; 21:715-726. [PMID: 35105293 PMCID: PMC10207907 DOI: 10.2174/1570159x20666220201091006] [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: 10/14/2021] [Revised: 01/11/2022] [Accepted: 01/26/2022] [Indexed: 02/05/2023] Open
Abstract
Cannabinoids are compounds isolated from cannabis and are also widely present in both nervous and immune systems of animals. In recent years, with in-depth research on cannabinoids, their clinical medicinal value has been evaluated, and many exciting achievements have been continuously accumulating, especially in the field of neurodegenerative disease. Alzheimer's disease is the most common type of neurodegenerative disease that causes dementia and has become a global health problem that seriously impacts human health today. In this review, we discuss the therapeutic potential of cannabinoids for the treatment of Alzheimer's disease. How cannabinoids act on different endocannabinoid receptor subtypes to regulate Alzheimer's disease and the roles of the endocannabinoid system in Alzheimer's disease are outlined, and the underlying mechanisms are discussed. Finally, we summarize the most relevant opportunities of cannabinoid pharmacology related to Alzheimer's disease and discuss the potential usefulness of cannabinoids in the clinical treatment of Alzheimer's disease.
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Affiliation(s)
- Shuangtao Li
- Shantou University Medical College, Brain Function and Disease Laboratory, Shantou, #22 Road Xinling, Guangdong 515041, China
| | - Yuanbing Huang
- Department of Neurology, Yunfu People’s Hospital, Yunfu, Guangdong 527300, China
| | - Lijun Yu
- Shantou University Medical College, Brain Function and Disease Laboratory, Shantou, #22 Road Xinling, Guangdong 515041, China
| | - Xiaoyu Ji
- Department of Neurology, Yunfu People’s Hospital, Yunfu, Guangdong 527300, China
| | - Jie Wu
- Shantou University Medical College, Brain Function and Disease Laboratory, Shantou, #22 Road Xinling, Guangdong 515041, China
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Eraso‐Pichot A, Pouvreau S, Olivera‐Pinto A, Gomez‐Sotres P, Skupio U, Marsicano G. Endocannabinoid signaling in astrocytes. Glia 2023; 71:44-59. [PMID: 35822691 PMCID: PMC9796923 DOI: 10.1002/glia.24246] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 06/28/2022] [Accepted: 07/04/2022] [Indexed: 01/07/2023]
Abstract
The study of the astrocytic contribution to brain functions has been growing in popularity in the neuroscience field. In the last years, and especially since the demonstration of the involvement of astrocytes in synaptic functions, the astrocyte field has revealed multiple functions of these cells that seemed inconceivable not long ago. In parallel, cannabinoid investigation has also identified different ways by which cannabinoids are able to interact with these cells, modify their functions, alter their communication with neurons and impact behavior. In this review, we will describe the expression of different endocannabinoid system members in astrocytes. Moreover, we will relate the latest findings regarding cannabinoid modulation of some of the most relevant astroglial functions, namely calcium (Ca2+ ) dynamics, gliotransmission, metabolism, and inflammation.
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Affiliation(s)
- Abel Eraso‐Pichot
- U1215 Neurocentre MagendieInstitut national de la santé et de la recherche médicale (INSERM)BordeauxFrance,University of BordeauxBordeauxFrance
| | - Sandrine Pouvreau
- U1215 Neurocentre MagendieInstitut national de la santé et de la recherche médicale (INSERM)BordeauxFrance,University of BordeauxBordeauxFrance
| | - Alexandre Olivera‐Pinto
- U1215 Neurocentre MagendieInstitut national de la santé et de la recherche médicale (INSERM)BordeauxFrance,University of BordeauxBordeauxFrance
| | - Paula Gomez‐Sotres
- U1215 Neurocentre MagendieInstitut national de la santé et de la recherche médicale (INSERM)BordeauxFrance,University of BordeauxBordeauxFrance
| | - Urszula Skupio
- U1215 Neurocentre MagendieInstitut national de la santé et de la recherche médicale (INSERM)BordeauxFrance,University of BordeauxBordeauxFrance
| | - Giovanni Marsicano
- U1215 Neurocentre MagendieInstitut national de la santé et de la recherche médicale (INSERM)BordeauxFrance,University of BordeauxBordeauxFrance
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7
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Hagan K, Varelas P, Zheng H. Endocannabinoid System of the Blood-Brain Barrier: Current Understandings and Therapeutic Potentials. Cannabis Cannabinoid Res 2022; 7:561-568. [PMID: 34918950 PMCID: PMC9587775 DOI: 10.1089/can.2021.0101] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The endocannabinoid system (ECS) has been found at the blood-brain barrier (BBB), as Cannabinoid receptors were characterized in human brain microvascular endothelial cells and astrocytes. In several in vitro and in vivo studies, cannabinoids decreased BBB permeability and enhanced membrane integrity, which may be achieved through endothelial tight junctions and other mechanisms. These permeability regulation effects of cannabinoids suggested that the ECS may protect the brain by enhancing barrier integrity. Related questions about cannabinoid-drug interaction and drug distribution across the BBB are also raised. Specifically, can cannabinoids significantly reduce drug bioavailability to the brain? More in-depth and systematic investigations are needed to characterize and quantify these effects of cannabinoids on brain microvasculature physiopathology. Therefore, this review summarizes literatures from different disciplines to promote more research on assessing the therapeutic benefits and risks of using cannabinoids to protect BBB from dysfunctions or breakdown, and to avoid consequent brain damages due to inflammation, neurodegenerations, hemorrhage, ischemia, or other causes.
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Affiliation(s)
- Kofi Hagan
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, New York, USA
| | | | - HaiAn Zheng
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, New York, USA
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8
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Young AP, Denovan-Wright EM. The Dynamic Role of Microglia and the Endocannabinoid System in Neuroinflammation. Front Pharmacol 2022; 12:806417. [PMID: 35185547 PMCID: PMC8854262 DOI: 10.3389/fphar.2021.806417] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 12/24/2021] [Indexed: 12/13/2022] Open
Abstract
Microglia, the resident immune cells of the brain, can take on a range of pro- or anti-inflammatory phenotypes to maintain homeostasis. However, the sustained activation of pro-inflammatory microglia can lead to a state of chronic neuroinflammation characterized by high concentrations of neurotoxic soluble factors throughout the brain. In healthy brains, the inflammatory processes cease and microglia transition to an anti-inflammatory phenotype, but failure to halt the pro-inflammatory processes is a characteristic of many neurological disorders. The endocannabinoid system has been identified as a promising therapeutic target for chronic neuroinflammation as there is evidence that synthetic and endogenously produced cannabinoids temper the pro-inflammatory response of microglia and may encourage a switch to an anti-inflammatory phenotype. Activation of cannabinoid type 2 (CB2) receptors has been proposed as the mechanism of action responsible for these effects. The abundance of components of the endocannabinoid system in microglia also change dynamically in response to several brain pathologies. This can impact the ability of microglia to synthesize and degrade endocannabinoids or react to endogenous and exogenous cannabinoids. Cannabinoid receptors also participate in the formation of receptor heteromers which influences their function specifically in cells that express both receptors, such as microglia. This creates opportunities for drug-drug interactions between CB2 receptor-targeted therapies and other classes of drugs. In this article, we review the roles of pro- and anti-inflammatory microglia in the development and resolution of neuroinflammation. We also discuss the fluctuations observed in the components of the endocannabinoid in microglia and examine the potential of CB2 receptors as a therapeutic target in this context.
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CB2 Receptor in Microglia: The Guardian of Self-Control. Int J Mol Sci 2020; 22:ijms22010019. [PMID: 33375006 PMCID: PMC7792761 DOI: 10.3390/ijms22010019] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/16/2020] [Accepted: 12/18/2020] [Indexed: 12/12/2022] Open
Abstract
Microglia are key to maintaining the homeostasis of the brain. These immune cells of the brain can be our biggest ally in fighting infections, but can worsen pathology or hinder recovery when uncontrolled. Thus, understanding how microglia contribute to neuroinflammatory processes and how their activity can be controlled is of great importance. It is known that activation of endocannabinoid system, and especially the cannabinoid type 2 receptor (CB2R), decreases inflammation. Alongside its non-psychoactive effect, it makes the CB2R receptor a perfect target for treating diseases accompanied by neuroinflammation including neurodegenerative diseases. However, the exact mechanisms by which CB2R regulates microglial activity are not yet understood. Here, we review the current knowledge on the roles of microglial CB2R from in vitro and in vivo studies. We look into CB2R function under physiological and pathological conditions and focus on four different disease models representing chronic and acute inflammation. We highlight open questions and controversies and provide an update on the latest discoveries that were enabled by the development of novel technologies. Also, we discuss the recent findings on the role of microglia CB2R in cognition and its role in neuron–microglia communication.
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10
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The impact of cannabinoid type 2 receptors (CB2Rs) in neuroprotection against neurological disorders. Acta Pharmacol Sin 2020; 41:1507-1518. [PMID: 33024239 DOI: 10.1038/s41401-020-00530-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 09/06/2020] [Indexed: 12/12/2022] Open
Abstract
Cannabinoids have long been used for their psychotropic and possible medical properties of symptom relief. In the past few years, a vast literature shows that cannabinoids are neuroprotective under different pathological situations. Most of the effects of cannabinoids are mediated by the well-characterized cannabinoid receptors, the cannabinoid type 1 receptor (CB1R) and cannabinoid type 2 receptor (CB2R). Even though CB1Rs are highly expressed in the central nervous system (CNS), the adverse central side effects and the development of tolerance resulting from CB1R activation may ultimately limit the clinical utility of CB1R agonists. In contrast to the ubiquitous presence of CB1Rs, CB2Rs are less commonly expressed in the healthy CNS but highly upregulated in glial cells under neuropathological conditions. Experimental studies have provided robust evidence that CB2Rs seem to be involved in the modulation of different neurological disorders. In this paper, we summarize the current knowledge regarding the protective effects of CB2R activation against the development of neurological diseases and provide a perspective on the future of this field. A better understanding of the fundamental pharmacology of CB2R activation is essential for the development of clinical applications and the design of novel therapeutic strategies.
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11
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Pflanz CP, Charquero-Ballester M, Majid DSA, Winkler AM, Vallée E, Aron AR, Jenkinson M, Douaud G. One-year changes in brain microstructure differentiate preclinical Huntington's disease stages. NEUROIMAGE-CLINICAL 2019; 25:102099. [PMID: 31865023 PMCID: PMC6931230 DOI: 10.1016/j.nicl.2019.102099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 10/24/2019] [Accepted: 11/18/2019] [Indexed: 11/02/2022]
Abstract
OBJECTIVE To determine whether brain imaging markers of tissue microstructure can detect the effect of disease progression across the preclinical stages of Huntington's disease. METHODS Longitudinal microstructural changes in diffusion imaging metrics (mean diffusivity and fractional anisotropy) were investigated in participants with presymptomatic Huntington's disease (N = 35) stratified into three preclinical subgroups according to their estimated time until onset of symptoms, compared with age- and gender-matched healthy controls (N = 19) over a 1y period. RESULTS Significant differences were found over the four groups in change of mean diffusivity in the posterior basal ganglia and the splenium of the corpus callosum. This overall effect was driven by significant differences between the group far-from-onset (FAR) of symptoms and the groups midway- (MID) and near-the-onset (NEAR) of symptoms. In particular, an initial decrease of mean diffusivity in the FAR group was followed by a subsequent increase in groups closer to onset of symptoms. The seemingly counter-intuitive decrease of mean diffusivity in the group furthest from onset of symptoms might be an early indicator of neuroinflammatory process preceding the neurodegenerative phase. In contrast, the only clinical measure that was able to capture a difference in 1y changes between the preclinical stages was the UHDRS confidence in motor score. CONCLUSIONS With sensitivity to longitudinal changes in brain microstructure within and between preclinical stages, and potential differential response to distinct pathophysiological mechanisms, diffusion imaging is a promising state marker for monitoring treatment response and identifying the optimal therapeutic window of opportunity in preclinical Huntington's disease.
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Affiliation(s)
- Chris Patrick Pflanz
- Oxford Centre for Functional MRI of the Brain (FMRIB), Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences, University of Oxford, UK
| | - Marina Charquero-Ballester
- Oxford Centre for Functional MRI of the Brain (FMRIB), Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences, University of Oxford, UK; Department of Psychiatry, University of Oxford, UK
| | - D S Adnan Majid
- Department of Psychology, University of California, San Diego (UCSD), San Diego, California, USA
| | - Anderson M Winkler
- Oxford Centre for Functional MRI of the Brain (FMRIB), Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences, University of Oxford, UK
| | - Emmanuel Vallée
- Oxford Centre for Functional MRI of the Brain (FMRIB), Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences, University of Oxford, UK
| | - Adam R Aron
- Department of Psychology, University of California, San Diego (UCSD), San Diego, California, USA
| | - Mark Jenkinson
- Oxford Centre for Functional MRI of the Brain (FMRIB), Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences, University of Oxford, UK
| | - Gwenaëlle Douaud
- Oxford Centre for Functional MRI of the Brain (FMRIB), Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences, University of Oxford, UK.
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12
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Palpagama TH, Waldvogel HJ, Faull RLM, Kwakowsky A. The Role of Microglia and Astrocytes in Huntington's Disease. Front Mol Neurosci 2019; 12:258. [PMID: 31708741 PMCID: PMC6824292 DOI: 10.3389/fnmol.2019.00258] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Accepted: 10/10/2019] [Indexed: 12/21/2022] Open
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disease. HD patients present with movement disorders, behavioral and psychiatric symptoms and cognitive decline. This review summarizes the contribution of microglia and astrocytes to HD pathophysiology. Neuroinflammation in the HD brain is characterized by a reactive morphology in these glial cells. Microglia and astrocytes are critical in regulating neuronal activity and maintaining an optimal milieu for neuronal function. Previous studies provide evidence that activated microglia and reactive astrocytes contribute to HD pathology through transcriptional activation of pro-inflammatory genes to perpetuate a chronic inflammatory state. Reactive astrocytes also display functional changes in glutamate and ion homeostasis and energy metabolism. Astrocytic and microglial changes may further contribute to the neuronal death observed with the progression of HD. Importantly, the degree to which these neuroinflammatory changes are detrimental to neurons and contribute to the progression of HD pathology is not well understood. Furthermore, recent observations provide compelling evidence that activated microglia and astrocytes exert a variety of beneficial functions that are essential for limiting tissue damage and preserving neuronal function in the HD brain. Therefore, a better understanding of the neuroinflammatory environment in the brain in HD may lead to the development of targeted and innovative therapeutic opportunities.
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Affiliation(s)
- Thulani H Palpagama
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Henry J Waldvogel
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Richard L M Faull
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Andrea Kwakowsky
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
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13
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Denis HL, Lauruol F, Cicchetti F. Are immunotherapies for Huntington's disease a realistic option? Mol Psychiatry 2019; 24:364-377. [PMID: 29487401 DOI: 10.1038/s41380-018-0021-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 12/22/2017] [Accepted: 01/15/2018] [Indexed: 01/28/2023]
Abstract
There is compelling evidence that the pathophysiology of many neurodegenerative diseases includes dysregulation of the immune system, with some elements that precede disease onset. However, if these alterations are prominent, why have clinical trials targeting this system failed to translate into long-lasting meaningful benefits for patients? This review focuses on Huntington's disease, a genetic disorder marked by notable cerebral and peripheral inflammation. We summarize ongoing and completed clinical trials that have involved pharmacological approaches to inhibit various components of the immune system and their pre-clinical correlates. We then discuss new putative treatment strategies using more targeted immunotherapies such as vaccination and intrabodies and how these may offer new hope in the treatment of Huntington's disease as well as other neurodegenerative diseases.
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Affiliation(s)
- Hélèna L Denis
- Centre de Recherche du CHU de Québec, Université Laval, Québec, QC, G1V 4G2, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, G1V 0A6, Canada
| | - Florian Lauruol
- Centre de Recherche du CHU de Québec, Université Laval, Québec, QC, G1V 4G2, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, G1V 0A6, Canada
| | - Francesca Cicchetti
- Centre de Recherche du CHU de Québec, Université Laval, Québec, QC, G1V 4G2, Canada. .,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, G1V 0A6, Canada.
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14
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Aymerich MS, Aso E, Abellanas MA, Tolon RM, Ramos JA, Ferrer I, Romero J, Fernández-Ruiz J. Cannabinoid pharmacology/therapeutics in chronic degenerative disorders affecting the central nervous system. Biochem Pharmacol 2018; 157:67-84. [PMID: 30121249 DOI: 10.1016/j.bcp.2018.08.016] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 08/13/2018] [Indexed: 12/12/2022]
Abstract
The endocannabinoid system (ECS) exerts a modulatory effect of important functions such as neurotransmission, glial activation, oxidative stress, or protein homeostasis. Dysregulation of these cellular processes is a common neuropathological hallmark in aging and in neurodegenerative diseases of the central nervous system (CNS). The broad spectrum of actions of cannabinoids allows targeting different aspects of these multifactorial diseases. In this review, we examine the therapeutic potential of the ECS for the treatment of chronic neurodegenerative diseases of the CNS focusing on Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. First, we describe the localization of the molecular components of the ECS and how they are altered under neurodegenerative conditions, either contributing to or protecting cells from degeneration. Second, we address recent advances in the modulation of the ECS using experimental models through different strategies including the direct targeting of cannabinoid receptors with agonists or antagonists, increasing the endocannabinoid tone by the inhibition of endocannabinoid hydrolysis, and activation of cannabinoid receptor-independent effects. Preclinical evidence indicates that cannabinoid pharmacology is complex but supports the therapeutic potential of targeting the ECS. Third, we review the clinical evidence and discuss the future perspectives on how to bridge human and animal studies to develop cannabinoid-based therapies for each neurodegenerative disorder. Finally, we summarize the most relevant opportunities of cannabinoid pharmacology related to each disease and the multiple unexplored pathways in cannabinoid pharmacology that could be useful for the treatment of neurodegenerative diseases.
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Affiliation(s)
- Maria S Aymerich
- Universidad de Navarra, Facultad de Ciencias, Departamento de Bioquímica y Genética, Pamplona, Spain; Universidad de Navarra, CIMA, Programa de Neurociencias, Pamplona, Spain; IdiSNA, Instituto de Investigación Sanitaria de Navarra, Spain.
| | - Ester Aso
- Departamento de Patología y Terapéutica Experimental, Universidad de Barcelona, L'Hospitalet de Llobregat, Spain; CIBERNED, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Instituto de Salud Carlos III, Spain
| | - Miguel A Abellanas
- Universidad de Navarra, Facultad de Ciencias, Departamento de Bioquímica y Genética, Pamplona, Spain; Universidad de Navarra, CIMA, Programa de Neurociencias, Pamplona, Spain
| | - Rosa M Tolon
- Facultad de Ciencias Experimentales, Universidad Francisco de Vitoria, Pozuelo de Alarcón, Spain
| | - Jose A Ramos
- CIBERNED, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Instituto de Salud Carlos III, Spain; Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain; IRYCIS, Instituto Ramón y Cajal de Investigación Sanitaria, Madrid, Spain
| | - Isidre Ferrer
- Departamento de Patología y Terapéutica Experimental, Universidad de Barcelona, L'Hospitalet de Llobregat, Spain; CIBERNED, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Instituto de Salud Carlos III, Spain
| | - Julian Romero
- Facultad de Ciencias Experimentales, Universidad Francisco de Vitoria, Pozuelo de Alarcón, Spain
| | - Javier Fernández-Ruiz
- CIBERNED, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Instituto de Salud Carlos III, Spain; Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain; IRYCIS, Instituto Ramón y Cajal de Investigación Sanitaria, Madrid, Spain
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15
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Localization of cannabinoid receptors CB1, CB2, GPR55, and PPARα in the canine gastrointestinal tract. Histochem Cell Biol 2018; 150:187-205. [DOI: 10.1007/s00418-018-1684-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2018] [Indexed: 12/26/2022]
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16
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Cooper A, Singh S, Hook S, Tyndall JDA, Vernall AJ. Chemical Tools for Studying Lipid-Binding Class A G Protein-Coupled Receptors. Pharmacol Rev 2017; 69:316-353. [PMID: 28655732 DOI: 10.1124/pr.116.013243] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 05/15/2017] [Indexed: 12/16/2022] Open
Abstract
Cannabinoid, free fatty acid, lysophosphatidic acid, sphingosine 1-phosphate, prostanoid, leukotriene, bile acid, and platelet-activating factor receptor families are class A G protein-coupled receptors with endogenous lipid ligands. Pharmacological tools are crucial for studying these receptors and addressing the many unanswered questions surrounding expression of these receptors in normal and diseased tissues. An inherent challenge for developing tools for these lipid receptors is balancing the often lipophilic requirements of the receptor-binding pharmacophore with favorable physicochemical properties to optimize highly specific binding. In this study, we review the radioligands, fluorescent ligands, covalent ligands, and antibodies that have been used to study these lipid-binding receptors. For each tool type, the characteristics and design rationale along with in vitro and in vivo applications are detailed.
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Affiliation(s)
- Anna Cooper
- School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - Sameek Singh
- School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - Sarah Hook
- School of Pharmacy, University of Otago, Dunedin, New Zealand
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17
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Kho DT, Glass M, Graham ES. Is the Cannabinoid CB 2 Receptor a Major Regulator of the Neuroinflammatory Axis of the Neurovascular Unit in Humans? CANNABINOID PHARMACOLOGY 2017; 80:367-396. [DOI: 10.1016/bs.apha.2017.03.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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18
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Navarro G, Morales P, Rodríguez-Cueto C, Fernández-Ruiz J, Jagerovic N, Franco R. Targeting Cannabinoid CB2 Receptors in the Central Nervous System. Medicinal Chemistry Approaches with Focus on Neurodegenerative Disorders. Front Neurosci 2016; 10:406. [PMID: 27679556 PMCID: PMC5020102 DOI: 10.3389/fnins.2016.00406] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/22/2016] [Indexed: 12/04/2022] Open
Abstract
Endocannabinoids activate two types of specific G-protein-coupled receptors (GPCRs), namely cannabinoid CB1 and CB2. Contrary to the psychotropic actions of agonists of CB1 receptors, and serious side effects of the selective antagonists of this receptor, drugs acting on CB2 receptors appear as promising drugs to combat CNS diseases (Parkinson's disease, Huntington's chorea, cerebellar ataxia, amyotrohic lateral sclerosis). Differential localization of CB2 receptors in neural cell types and upregulation in neuroinflammation are keys to understand the therapeutic potential in inter alia diseases that imply progressive neurodegeneration. Medicinal chemistry approaches are now engaged to develop imaging tools to map receptors in the living human brain, to develop more efficacious agonists, and to investigate the possibility to develop allosteric modulators.
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Affiliation(s)
- Gemma Navarro
- Department of Biochemistry and Molecular Biomedicine, University of BarcelonaBarcelona, Spain; Centro de Investigación en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos IIIMadrid, Spain; Cell and Molecular Neuropharmacology, Institut de Biomedicina (IBUB), Universitat de BarcelonaBarcelona, Spain
| | - Paula Morales
- Instituto de Química Médica, Consejo Superior de Investigaciones CientíficasMadrid, Spain; Center for Drug Discovery, University of North Carolina at GreensboroGreensboro, NC, USA
| | - Carmen Rodríguez-Cueto
- Centro de Investigación en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos IIIMadrid, Spain; Departamento de Bioquímica, Facultad de Medicina, Instituto Universitario de Investigación en Neuroquímica, Universidad ComplutenseMadrid, Spain; Instituto Ramón y Cajal de Investigación SanitariaMadrid, Spain
| | - Javier Fernández-Ruiz
- Centro de Investigación en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos IIIMadrid, Spain; Departamento de Bioquímica, Facultad de Medicina, Instituto Universitario de Investigación en Neuroquímica, Universidad ComplutenseMadrid, Spain; Instituto Ramón y Cajal de Investigación SanitariaMadrid, Spain
| | - Nadine Jagerovic
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas Madrid, Spain
| | - Rafael Franco
- Department of Biochemistry and Molecular Biomedicine, University of BarcelonaBarcelona, Spain; Centro de Investigación en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos IIIMadrid, Spain; Cell and Molecular Neuropharmacology, Institut de Biomedicina (IBUB), Universitat de BarcelonaBarcelona, Spain
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19
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Bisogno T, Oddi S, Piccoli A, Fazio D, Maccarrone M. Type-2 cannabinoid receptors in neurodegeneration. Pharmacol Res 2016; 111:721-730. [DOI: 10.1016/j.phrs.2016.07.021] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/14/2016] [Accepted: 07/19/2016] [Indexed: 01/01/2023]
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20
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Benyó Z, Ruisanchez É, Leszl-Ishiguro M, Sándor P, Pacher P. Endocannabinoids in cerebrovascular regulation. Am J Physiol Heart Circ Physiol 2016; 310:H785-801. [PMID: 26825517 DOI: 10.1152/ajpheart.00571.2015] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 01/25/2016] [Indexed: 02/08/2023]
Abstract
The cerebral blood flow is tightly regulated by myogenic, endothelial, metabolic, and neural mechanisms under physiological conditions, and a large body of recent evidence indicates that inflammatory pathways have a major influence on the cerebral blood perfusion in certain central nervous system disorders, like hemorrhagic and ischemic stroke, traumatic brain injury, and vascular dementia. All major cell types involved in cerebrovascular control pathways (i.e., smooth muscle, endothelium, neurons, astrocytes, pericytes, microglia, and leukocytes) are capable of synthesizing endocannabinoids and/or express some or several of their target proteins [i.e., the cannabinoid 1 and 2 (CB1 and CB2) receptors and the transient receptor potential vanilloid type 1 ion channel]. Therefore, the endocannabinoid system may importantly modulate the regulation of cerebral circulation under physiological and pathophysiological conditions in a very complex manner. Experimental data accumulated since the late 1990s indicate that the direct effect of cannabinoids on cerebral vessels is vasodilation mediated, at least in part, by CB1 receptors. Cannabinoid-induced cerebrovascular relaxation involves both a direct inhibition of smooth muscle contractility and a release of vasodilator mediator(s) from the endothelium. However, under stress conditions (e.g., in conscious restrained animals or during hypoxia and hypercapnia), cannabinoid receptor activation was shown to induce a reduction of the cerebral blood flow, probably via inhibition of the electrical and/or metabolic activity of neurons. Finally, in certain cerebrovascular pathologies (e.g., subarachnoid hemorrhage, as well as traumatic and ischemic brain injury), activation of CB2 (and probably yet unidentified non-CB1/non-CB2) receptors appear to improve the blood perfusion of the brain via attenuating vascular inflammation.
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Affiliation(s)
- Zoltán Benyó
- Institute of Clinical Experimental Research, Semmelweis University, Budapest, Hungary; and
| | - Éva Ruisanchez
- Institute of Clinical Experimental Research, Semmelweis University, Budapest, Hungary; and
| | - Miriam Leszl-Ishiguro
- Institute of Clinical Experimental Research, Semmelweis University, Budapest, Hungary; and
| | - Péter Sándor
- Institute of Clinical Experimental Research, Semmelweis University, Budapest, Hungary; and
| | - Pál Pacher
- Laboratory of Cardiovascular Physiology and Tissue Injury, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland
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21
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Fernández-Ruiz J, Romero J, Ramos JA. Endocannabinoids and Neurodegenerative Disorders: Parkinson's Disease, Huntington's Chorea, Alzheimer's Disease, and Others. Handb Exp Pharmacol 2015; 231:233-59. [PMID: 26408163 DOI: 10.1007/978-3-319-20825-1_8] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This review focuses on the role of the endocannabinoid signaling system in controlling neuronal survival, an extremely important issue to be considered when developing new therapies for neurodegenerative disorders. First, we will describe the cellular and molecular mechanisms, and the signaling pathways, underlying these neuroprotective properties, including the control of glutamate homeostasis, calcium influx, the toxicity of reactive oxygen species, glial activation and other inflammatory events; and the induction of autophagy. We will then concentrate on the preclinical studies and the few clinical trials that have been carried out targeting endocannabinoid signaling in three important chronic progressive neurodegenerative disorders (Parkinson's disease, Huntington's chorea, and Alzheimer's disease), as well as in other less well-studied disorders. We will end by offering some ideas and proposals for future research that should be carried out to optimize endocannabinoid-based treatments for these disorders. Such studies will strengthen the possibility that these therapies will be investigated in the clinical scenario and licensed for their use in specific disorders.
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Affiliation(s)
- Javier Fernández-Ruiz
- Facultad de Medicina, Departamento de Bioquímica y Biología Molecular III, Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense, Ciudad Universitaria s/n, 28040, Madrid, Spain.
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.
| | - Julián Romero
- Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón, Madrid, Spain
- Departamento de Ciencias Biosanitarias, Universidad Francisco de Vitoria, Madrid, Spain
| | - José A Ramos
- Facultad de Medicina, Departamento de Bioquímica y Biología Molecular III, Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense, Ciudad Universitaria s/n, 28040, Madrid, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
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22
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Abstract
The endocannabinoid system consists of endogenous cannabinoids (endocannabinoids), the enzymes that synthesize and degrade endocannabinoids, and the receptors that transduce the effects of endocannabinoids. Much of what we know about the function of endocannabinoids comes from studies that combine localization of endocannabinoid system components with physiological or behavioral approaches. This review will focus on the localization of the best-known components of the endocannabinoid system for which the strongest anatomical evidence exists.
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23
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Fernández-Ruiz J, Moro MA, Martínez-Orgado J. Cannabinoids in Neurodegenerative Disorders and Stroke/Brain Trauma: From Preclinical Models to Clinical Applications. Neurotherapeutics 2015; 12:793-806. [PMID: 26260390 PMCID: PMC4604192 DOI: 10.1007/s13311-015-0381-7] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cannabinoids form a singular family of plant-derived compounds (phytocannabinoids), endogenous signaling lipids (endocannabinoids), and synthetic derivatives with multiple biological effects and therapeutic applications in the central and peripheral nervous systems. One of these properties is the regulation of neuronal homeostasis and survival, which is the result of the combination of a myriad of effects addressed to preserve, rescue, repair, and/or replace neurons, and also glial cells against multiple insults that may potentially damage these cells. These effects are facilitated by the location of specific targets for the action of these compounds (e.g., cannabinoid type 1 and 2 receptors, endocannabinoid inactivating enzymes, and nonendocannabinoid targets) in key cellular substrates (e.g., neurons, glial cells, and neural progenitor cells). This potential is promising for acute and chronic neurodegenerative pathological conditions. In this review, we will collect all experimental evidence, mainly obtained at the preclinical level, supporting that different cannabinoid compounds may be neuroprotective in adult and neonatal ischemia, brain trauma, Alzheimer's disease, Parkinson's disease, Huntington's chorea, and amyotrophic lateral sclerosis. This increasing experimental evidence demands a prompt clinical validation of cannabinoid-based medicines for the treatment of all these disorders, which, at present, lack efficacious treatments for delaying/arresting disease progression, despite the fact that the few clinical trials conducted so far with these medicines have failed to demonstrate beneficial effects.
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Affiliation(s)
- Javier Fernández-Ruiz
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense, Madrid, Spain.
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.
| | - María A Moro
- Departamento de Farmacología, Facultad de Medicina, Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense, 28040, Madrid, Spain
- Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain
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24
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Savonenko AV, Melnikova T, Wang Y, Ravert H, Gao Y, Koppel J, Lee D, Pletnikova O, Cho E, Sayyida N, Hiatt A, Troncoso J, Davies P, Dannals RF, Pomper MG, Horti AG. Cannabinoid CB2 Receptors in a Mouse Model of Aβ Amyloidosis: Immunohistochemical Analysis and Suitability as a PET Biomarker of Neuroinflammation. PLoS One 2015; 10:e0129618. [PMID: 26086915 PMCID: PMC4472959 DOI: 10.1371/journal.pone.0129618] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 05/11/2015] [Indexed: 11/18/2022] Open
Abstract
In Alzheimer's disease (AD), one of the early responses to Aβ amyloidosis is recruitment of microglia to areas of new plaque. Microglial receptors such as cannabinoid receptor 2 (CB2) might be a suitable target for development of PET radiotracers that could serve as imaging biomarkers of Aβ-induced neuroinflammation. Mouse models of amyloidosis (J20APPswe/ind and APPswe/PS1ΔE9) were used to investigate the cellular distribution of CB2 receptors. Specificity of CB2 antibody (H60) was confirmed using J20APPswe/ind mice lacking CB2 receptors. APPswe/PS1ΔE9 mice were used in small animal PET with a CB2-targeting radiotracer, [11C]A836339. These studies revealed increased binding of [11C]A836339 in amyloid-bearing mice. Specificity of the PET signal was confirmed in a blockade study with a specific CB2 antagonist, AM630. Confocal microscopy revealed that CB2-receptor immunoreactivity was associated with astroglial (GFAP) and, predominantly, microglial (CD68) markers. CB2 receptors were observed, in particular, in microglial processes forming engulfment synapses with Aβ plaques. In contrast to glial cells, neuron (NeuN)-derived CB2 signal was equal between amyloid-bearing and control mice. The pattern of neuronal CB2 staining in amyloid-bearing mice was similar to that in human cases of AD. The data collected in this study indicate that Aβ amyloidosis without concomitant tau pathology is sufficient to activate CB2 receptors that are suitable as an imaging biomarker of neuroinflammation. The main source of enhanced CB2 PET binding in amyloid-bearing mice is increased CB2 immunoreactivity in activated microglia. The presence of CB2 immunoreactivity in neurons does not likely contribute to the enhanced CB2 PET signal in amyloid-bearing mice due to a lack of significant neuronal loss in this model. However, significant loss of neurons as seen at late stages of AD might decrease the CB2 PET signal due to loss of neuronally-derived CB2. Thus this study in mouse models of AD indicates that a CB2-specific radiotracer can be used as a biomarker of neuroinflammation in the early preclinical stages of AD, when no significant neuronal loss has yet developed.
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Affiliation(s)
- Alena V. Savonenko
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- Departments of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- * E-mail: (AGH); (AS)
| | - Tatiana Melnikova
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Yuchuan Wang
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Hayden Ravert
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Yongjun Gao
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Jeremy Koppel
- Litwin-Zucker Research Center, Feinstein Institute for Medical Research, North-Shore Long Island Jewish Health System, Manhasset, NY, United States of America
| | - Deidre Lee
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Olga Pletnikova
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Eugenia Cho
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Nuzhat Sayyida
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Andrew Hiatt
- MAPP Biopharmaceutical Inc, San-Diego, CA, United States of America
| | - Juan Troncoso
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- Departments of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Peter Davies
- Litwin-Zucker Research Center, Feinstein Institute for Medical Research, North-Shore Long Island Jewish Health System, Manhasset, NY, United States of America
| | - Robert F. Dannals
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Martin G. Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Andrew G. Horti
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- * E-mail: (AGH); (AS)
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25
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Crotti A, Glass CK. The choreography of neuroinflammation in Huntington's disease. Trends Immunol 2015; 36:364-73. [PMID: 26001312 PMCID: PMC4786070 DOI: 10.1016/j.it.2015.04.007] [Citation(s) in RCA: 152] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 04/19/2015] [Accepted: 04/19/2015] [Indexed: 01/01/2023]
Abstract
Currently, the concept of 'neuroinflammation' includes inflammation associated with neurodegenerative diseases, in which there is little or no infiltration of blood-derived immune cells into the brain. The roles of brain-resident and peripheral immune cells in these inflammatory settings are poorly understood, and it is unclear whether neuroinflammation results from immune reaction to neuronal dysfunction/degeneration, and/or represents cell-autonomous phenotypes of dysfunctional immune cells. Here, we review recent studies examining these questions in the context of Huntington's disease (HD), where mutant Huntingtin (HTT) is expressed in both neurons and glia. Insights into the cellular and molecular mechanisms underlying neuroinflammation in HD may provide a better understanding of inflammation in more complex neurodegenerative disorders, and of the contribution of the neuroinflammatory component to neurodegenerative disease pathogenesis.
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Affiliation(s)
| | - Christopher K Glass
- Department of Cellular and Molecular Medicine, University of California San Diego, CA, USA; Department of Medicine, University of California San Diego, CA, USA.
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