151
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Yin AQ, Wang F, Zhang X. Integrating endocannabinoid signaling in the regulation of anxiety and depression. Acta Pharmacol Sin 2019; 40:336-341. [PMID: 30002489 DOI: 10.1038/s41401-018-0051-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 05/20/2018] [Indexed: 01/02/2023] Open
Abstract
Brain endogenous cannabinoid (eCB) signaling seems to harmonize appropriate behavioral responses, which are essential for the organism's long-term viability and homeostasis. Dysregulation of eCB signaling contributes to negative emotional states and increased stress responses. An understanding of the underlying neural cell populations and neural circuit regulation will enable the development of therapeutic strategies to mitigate behavioral maladaptation and provide insight into the influence of eCB on the neural circuits involved in anxiety and depression. This review focuses on recent evidence that has added a new layer of complexity to the idea of targeting the eCB system for therapeutic benefits in neuropsychiatric disease and on the future research direction of neural circuit modulation.
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152
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Jordan CJ, Xi ZX. Progress in brain cannabinoid CB 2 receptor research: From genes to behavior. Neurosci Biobehav Rev 2019; 98:208-220. [PMID: 30611802 PMCID: PMC6401261 DOI: 10.1016/j.neubiorev.2018.12.026] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 12/12/2018] [Accepted: 12/22/2018] [Indexed: 01/01/2023]
Abstract
The type 2 cannabinoid receptor (CB2R) was initially regarded as a peripheral cannabinoid receptor. However, recent technological advances in gene detection, alongside the availability of transgenic mouse lines, indicate that CB2Rs are expressed in both neurons and glial cells in the brain under physiological and pathological conditions, and are involved in multiple functions at cellular and behavioral levels. Brain CB2Rs are inducible and neuroprotective via up-regulation in response to various insults, but display species differences in gene and receptor structures, CB2R expression, and receptor responses to various CB2R ligands. CB2R transcripts also differ between the brain and spleen. In the brain, CB2A is the major transcript isoform, while CB2A and CB2B transcripts are present at higher levels in the spleen. These new findings regarding brain versus spleen CB2R isoforms may in part explain why early studies failed to detect brain CB2R gene expression. Here, we review evidence supporting the expression and function of brain CB2R from gene and receptor levels to cellular functioning, neural circuitry, and animal behavior.
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Affiliation(s)
- Chloe J Jordan
- Addiction Biology Unit, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, MD, 21224, USA
| | - Zheng-Xiong Xi
- Addiction Biology Unit, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, MD, 21224, USA.
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153
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Potential Mechanisms Underlying the Deleterious Effects of Synthetic Cannabinoids Found in Spice/K2 Products. Brain Sci 2019; 9:brainsci9010014. [PMID: 30654473 PMCID: PMC6357179 DOI: 10.3390/brainsci9010014] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 01/11/2019] [Accepted: 01/13/2019] [Indexed: 12/17/2022] Open
Abstract
The chief psychoactive constituent of many bioactive phytocannabinoids (Δ9-tetrahydrocannabinol, Δ9-THC) found in hemp, cannabis or marijuana plants are scientifically denoted by the Latin term, Cannabis sativa, acts on cell surface receptors. These receptors are ubiquitously expressed. To date, two cannabinoid receptors have been cloned and characterized. Cannabinoid receptor type 1 (CB1R) is found to serve as the archetype for cannabinoid action in the brain. They have attracted wide interest as the mediator of all psychoactive properties of exogenous and endogenous cannabinoids and they are abundantly expressed on most inhibitory and excitatory neurons. Recent evidence established that cannabinoid receptor type 2 (CB2R) is also expressed in the neurons at both presynaptic and postsynaptic terminals and are involved in neuropsychiatric effects. Distinct types of cells in many regions in the brain express CB2Rs and the cellular origin of CB2Rs that induce specific behavioral effects are emerging. To mimic the bliss effects of marijuana, synthetic cannabinoids (SCBs) have been sprayed onto plant material, and this plant material has been consequently packaged and sold under brand name “Spice” or “K2”. These SCBs have been shown to maintain their affinity and functional activity for CB1R and CB2R and have been shown to cause severe harmful effects when compared to the effects of Δ9-THC. The present review discusses the potential brain mechanisms that are involved in the deleterious effects of SCBs.
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154
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Crystal Structure of the Human Cannabinoid Receptor CB2. Cell 2019; 176:459-467.e13. [PMID: 30639103 DOI: 10.1016/j.cell.2018.12.011] [Citation(s) in RCA: 252] [Impact Index Per Article: 50.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 10/31/2018] [Accepted: 12/07/2018] [Indexed: 11/21/2022]
Abstract
The cannabinoid receptor CB2 is predominately expressed in the immune system, and selective modulation of CB2 without the psychoactivity of CB1 has therapeutic potential in inflammatory, fibrotic, and neurodegenerative diseases. Here, we report the crystal structure of human CB2 in complex with a rationally designed antagonist, AM10257, at 2.8 Å resolution. The CB2-AM10257 structure reveals a distinctly different binding pose compared with CB1. However, the extracellular portion of the antagonist-bound CB2 shares a high degree of conformational similarity with the agonist-bound CB1, which led to the discovery of AM10257's unexpected opposing functional profile of CB2 antagonism versus CB1 agonism. Further structural analysis using mutagenesis studies and molecular docking revealed the molecular basis of their function and selectivity for CB2 and CB1. Additional analyses of our designed antagonist and agonist pairs provide important insight into the activation mechanism of CB2. The present findings should facilitate rational drug design toward precise modulation of the endocannabinoid system.
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155
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Abstract
The family of chemical structures that interact with a cannabinoid receptor are broadly termed cannabinoids. Traditionally known for their psychotropic effects and their use as palliative medicine in cancer, cannabinoids are very versatile and are known to interact with several orphan receptors besides cannabinoid receptors (CBR) in the body. Recent studies have shown that several key pathways involved in cell growth, differentiation and, even metabolism and apoptosis crosstalk with cannabinoid signaling. Several of these pathways including AKT, EGFR, and mTOR are known to contribute to tumor development and metastasis, and cannabinoids may reverse their effects, thereby by inducing apoptosis, autophagy and modulating the immune system. In this book chapter, we explore how cannabinoids regulate diverse signaling mechanisms in cancer and immune cells within the tumor microenvironment and whether they impart a therapeutic effect. We also provide some important insight into the role of cannabinoids in cellular and whole body metabolism in the context of tumor inhibition. Finally, we highlight recent and ongoing clinical trials that include cannabinoids as a therapeutic strategy and several combinational approaches towards novel therapeutic opportunities in several invasive cancer conditions.
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156
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Abstract
Cannabinoids influence cardiovascular variables in health and disease via multiple mechanisms. The chapter covers the impact of cannabinoids on cardiovascular function in physiology and pathology and presents a critical analysis of the proposed signalling pathways governing regulation of cardiovascular function by endogenously produced and exogenous cannabinoids. We know that endocannabinoid system is overactivated under pathological conditions and plays both a protective compensatory role, such as in some forms of hypertension, atherosclerosis and other inflammatory conditions, and a pathophysiological role, such as in disease states associated with excessive hypotension. This chapter focuses on the mechanisms affecting hemodynamics and vasomotor effects of cannabinoids in health and disease states, highlighting mismatches between some studies. The chapter will first review the effects of marijuana smoking on cardiovascular system and then describe the impact of exogenous cannabinoids on cardiovascular parameters in humans and experimental animals. This will be followed by analysis of the impact of cannabinoids on reactivity of isolated vessels. The article critically reviews current knowledge on cannabinoid induction of vascular relaxation by cannabinoid receptor-dependent and -independent mechanisms and dysregulation of vascular endocannabinoid signaling in disease states.
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Affiliation(s)
- Alexander I Bondarenko
- Circulatory Physiology Department, Bogomoletz Institute of Physiology National Academy of Sciences of Ukraine, Kiev, Ukraine.
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157
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Wang J, Wang Y, Tong M, Pan H, Li D. New Prospect for Cancer Cachexia: Medical Cannabinoid. J Cancer 2019; 10:716-720. [PMID: 30719170 PMCID: PMC6360413 DOI: 10.7150/jca.28246] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 10/28/2018] [Indexed: 01/07/2023] Open
Abstract
Cachexia is a common term for the wasting symptoms which may appear in almost every chronic illness, such as AIDS, tuberculosis, and cancer. Cancer cachexia (CCA) is a result of the interaction between the host and the tumor, mainly manifested in short-term wasting, malnutrition, and so on. Due to the chronic food shortages, absorption dysfunction and metabolic disorders, all of these eventually lead to hypoimmunity, organ failure, and higher susceptibility to pathogenic microorganisms. And then increased morbidity and mortality rates as well as reduced tolerance to anti-cancer treatments will be resulted in patients with CCA. Up to now, no standard guidelines have been established for cachexia treatment. Moreover, progestagens, the only drugs approved by FDA for cancer-related cachexia, can only increase adipose tissue and have not been confirmed to augment lean body mass. Cannabinoid, such as Δ-9-tetrahydrocannabinol (THC) and cannabidiol, is one of a class of diverse chemical compounds. Previous studies have showed that cannabinoid had considerable potential to improve the appetite, body weight, body fat level, caloric intake, mood, quality of life in kinds of diseases. This review will elaborate the anti-CCA role of cannabinoid and explore that whether cannabinoid is effective for CCA and provide a basis for guiding clinical drug use.
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Affiliation(s)
| | | | | | | | - Da Li
- Department of Medical Oncology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
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158
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Endocannabinoid System and Alcohol Abuse Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1162:89-127. [PMID: 31332736 DOI: 10.1007/978-3-030-21737-2_6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Δ9-tetrahydrocannabinol (Δ9-THC), the primary active component in Cannabis sativa preparations such as hashish and marijuana, signals by binding to cell surface receptors. Two types of receptors have been cloned and characterized as cannabinoid (CB) receptors. CB1 receptors (CB1R) are ubiquitously present in the central nervous system (CNS) and are present in both inhibitory interneurons and excitatory neurons at the presynaptic terminal. CB2 receptors (CB2R) are demonstrated in microglial cells, astrocytes, and several neuron subpopulations and are present in both pre- and postsynaptic terminals. The majority of studies on these receptors have been conducted in the past two and half decades after the identification of the molecular constituents of the endocannabinoid (eCB) system that started with the characterization of CB1R. Subsequently, the seminal discovery was made, which suggested that alcohol (ethanol) alters the eCB system, thus establishing the contribution of the eCB system in the motivation to consume ethanol. Several preclinical studies have provided evidence that CB1R significantly contributes to the motivational and reinforcing properties of ethanol and that the chronic consumption of ethanol alters eCB transmitters and CB1R expression in the brain nuclei associated with addiction pathways. Additionally, recent seminal studies have further established the role of the eCB system in the development of ethanol-induced developmental disorders, such as fetal alcohol spectrum disorders (FASD). These results are augmented by in vitro and ex vivo studies, showing that acute and chronic treatment with ethanol produces physiologically relevant alterations in the function of the eCB system during development and in the adult stage. This chapter provides a current and comprehensive review of the literature concerning the role of the eCB system in alcohol abuse disorders (AUD).
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159
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Joshi N, Onaivi ES. Endocannabinoid System Components: Overview and Tissue Distribution. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1162:1-12. [PMID: 31332731 DOI: 10.1007/978-3-030-21737-2_1] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Abstract
Marijuana/cannabinoid research has been transformed into mainstream science during the last half-century. Evidence based research and remarkable biotechnological advances demonstrate that phytocannabinoids and endocannabinoid (eCBs) acting on cannabinoid receptors (CBRs) regulate various aspects of human physiological, behavioral, immunological and metabolic functions. The distribution and function of the components of the endocannabinoid system (ECS) in the central nervous system (CNS) and immune processes have garnished significant research focus with major milestones. With these advances in biotechnology, rapid extension of the ECS research in the periphery has gained momentum. In this chapter, we review the components and tissue distribution of this previously unknown but ubiquitous and complex ECS that is involved in almost all aspects of mammalian physiology and pathology.
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Affiliation(s)
- Neal Joshi
- Rowan University School of Osteopathic Medicine, Stratford, NJ, USA
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160
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Wu Q, Wang H. The spatiotemporal expression changes of CB2R in the hippocampus of rats following pilocarpine-induced status epilepticus. Epilepsy Res 2018; 148:8-16. [DOI: 10.1016/j.eplepsyres.2018.10.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 09/20/2018] [Accepted: 10/07/2018] [Indexed: 12/20/2022]
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161
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An overview of the cannabinoid type 2 receptor system and its therapeutic potential. Curr Opin Anaesthesiol 2018; 31:407-414. [PMID: 29794855 DOI: 10.1097/aco.0000000000000616] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE OF REVIEW This narrative review summarizes recent insights into the role of the cannabinoid type 2 (CB2) receptor as potential therapeutic target in neuropathic pain and neurodegenerative conditions. RECENT FINDINGS The cannabinoid system continues to receive attention as a therapeutic target. The CB2 receptor is primarily expressed on glial cells only when there is active inflammation and appears to be devoid of undesired psychotropic effects or addiction liability. The CB2 receptor has been shown to have potential as a therapeutic target in models of diseases with limited or no currently approved therapies, such as neuropathic pain and neurodegenerative conditions such as Alzheimer's disease. SUMMARY The functional involvement of CB2 receptor in neuropathic pain and other neuroinflammatory diseases highlights the potential therapeutic role of drugs acting at the CB2 receptor.
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162
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Machado KDC, Islam MT, Ali ES, Rouf R, Uddin SJ, Dev S, Shilpi JA, Shill MC, Reza HM, Das AK, Shaw S, Mubarak MS, Mishra SK, Melo-Cavalcante AADC. A systematic review on the neuroprotective perspectives of beta-caryophyllene. Phytother Res 2018; 32:2376-2388. [DOI: 10.1002/ptr.6199] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 07/25/2018] [Accepted: 08/25/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Keylla da Conceição Machado
- Northeast Biotechnology Network (RENORBIO), Postgraduate Program in Pharmaceutical Sciences; Federal University of Piauí; Teresina Brazil
| | - Muhammad Torequl Islam
- Department for Management of Science and Technology Development; Ton Duc Thang University; Ho Chi Minh City Vietnam
- Faculty of Pharmacy; Ton Duc Thang University; Ho Chi Minh City Vietnam
| | - Eunüs S. Ali
- Department of Product Development; Gaco Pharmaceuticals Limited; Dhaka Bangladesh
- Flinders University College of Medicine and Public Health; Bedford Park 5042 Adelaide Australia
| | - Razina Rouf
- Department of Pharmacy, Life Science Faculty; Bangabandhu Sheikh Mujibur Rahman Science and Technology University; Gopalganj Bangladesh
| | - Shaikh Jamal Uddin
- Pharmacy Discipline, Life Science School; Khulna University; Khulna Bangladesh
| | - Shrabanti Dev
- Pharmacy Discipline, Life Science School; Khulna University; Khulna Bangladesh
| | - Jamil A. Shilpi
- Pharmacy Discipline, Life Science School; Khulna University; Khulna Bangladesh
| | - Manik Chandra Shill
- Department of Pharmaceutical Sciences; North South University; Dhaka Bangladesh
| | - Hasan Mahmud Reza
- Department of Pharmaceutical Sciences; North South University; Dhaka Bangladesh
| | - Asish Kumar Das
- Pharmacy Discipline, Life Science School; Khulna University; Khulna Bangladesh
| | - Subrata Shaw
- Broad Institute of MIT and Harvard; 415 Main Street Cambridge MA 02142 USA
| | | | - Siddhartha Kumar Mishra
- Cancer Biology Laboratory, School of Biological Sciences (Zoology); Dr. Harisingh Gour Central University; Sagar India
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163
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Abstract
The trillions of synaptic connections within the human brain are shaped by experience and neuronal activity, both of which underlie synaptic plasticity and ultimately learning and memory. G protein-coupled receptors (GPCRs) play key roles in synaptic plasticity by strengthening or weakening synapses and/or shaping dendritic spines. While most studies of synaptic plasticity have focused on cell surface receptors and their downstream signaling partners, emerging data point to a critical new role for the very same receptors to signal from inside the cell. Intracellular receptors have been localized to the nucleus, endoplasmic reticulum, lysosome, and mitochondria. From these intracellular positions, such receptors may couple to different signaling systems, display unique desensitization patterns, and/or show distinct patterns of subcellular distribution. Intracellular GPCRs can be activated at the cell surface, endocytosed, and transported to an intracellular site or simply activated in situ by de novo ligand synthesis, diffusion of permeable ligands, or active transport of non-permeable ligands. Current findings reinforce the notion that intracellular GPCRs play a dynamic role in synaptic plasticity and learning and memory. As new intracellular GPCR roles are defined, the need to selectively tailor agonists and/or antagonists to both intracellular and cell surface receptors may lead to the development of more effective therapeutic tools.
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Affiliation(s)
- Yuh-Jiin I. Jong
- Department of Neuroscience, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Steven K. Harmon
- Department of Neuroscience, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Karen L. O’Malley
- Department of Neuroscience, Washington University School of Medicine, Saint Louis, MO 63110, USA
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164
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Role of the endocannabinoid system in drug addiction. Biochem Pharmacol 2018; 157:108-121. [PMID: 30217570 DOI: 10.1016/j.bcp.2018.09.013] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 09/10/2018] [Indexed: 12/20/2022]
Abstract
Drug addiction is a chronic relapsing disorder that produces a dramaticglobal health burden worldwide. Not effective treatment of drug addiction is currently available probably due to the difficulties to find an appropriate target to manage this complex disease raising the needs for further identification of novel therapeutic approaches. The endocannabinoid system has been found to play a crucial role in the neurobiological substrate underlying drug addiction. Endocannabinoids and cannabinoid receptors are widely expressed in the main areas of the mesocorticolimbic system that participate in the initiation and maintenance of drug consumption and in the development of compulsion and loss of behavioral control occurring during drug addiction. The identification of the important role played by CB1 cannabinoid receptors in drug addiction encouraged the possible used of an early commercialized CB1 receptor antagonist for treating drug addiction. However, the incidence of serious psychiatric adverse events leaded to the sudden withdrawal from the market of this CB1 antagonist and all the research programs developed by pharmaceutical companies to obtain new CB1 antagonists were stopped. Currently, new research strategies are under development to target the endocannabinoid system for drug addiction avoiding these side effects, which include allosteric negative modulators of CB1 receptors and compounds targeting CB2 receptors. Recent studies showing the potential role of CB2 receptors in the addictive properties of different drugs of abuse have open a promising research opportunity to develop novel possible therapeutic approaches.
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165
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Abstract
Epilepsy is considered to be one of the most common non-communicable neurological diseases especially in low to middle-income countries. Approximately one-third of patients with epilepsy have seizures that are resistant to antiepileptic medications. Clinical trials for the treatment of medically refractory epilepsy have mostly focused on new drug treatments, and result in a significant portion of subjects whose seizures remain refractory to medication. The off-label use of cannabis sativa plant in treating seizures is known since ancient times. The active ingredients of this plant are delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), the latter considered safer and more effective in treating seizures, and with less adverse psychotropic effects. Clinical trials prior to two years ago have shown little to no significant effects of cannabis in reducing seizures. These trials seem to be underpowered, with a sample size less than 15. In contrast, more recent studies that have included over 100 participants showed that CBD use resulted in a significant reduction in seizure frequency. Adverse effects of CBD overall appear to be benign, while more concerning adverse effects (e.g., elevated liver enzymes) improve with continued CBD use or dose reduction. In most of the trials, CBD is used in adjunct with epilepsy medication, therefore it remains to be determined whether CBD is itself antiepileptic or a potentiator of traditional antiepileptic medications. Future trials may evaluate the efficacy of CBD in treating seizures due to specific etiologies (e.g., post-traumatic, post-stroke, idiopathic).
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Affiliation(s)
- Sidra Zaheer
- Dow Medical College, Dow University of Health Sciences (DUHS), Karachi, PAK
| | - Deepak Kumar
- Internal Medicine, Jinnah Postgraduate Medical Centre, Karachi, PAK
| | | | | | - Fnu Kiran
- Internal Medicine, Basic Health Unit Larhi, Gambat, Gambat, PAK
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166
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Pharmacological inhibition of 2-arachidonoilglycerol hydrolysis enhances memory consolidation in rats through CB2 receptor activation and mTOR signaling modulation. Neuropharmacology 2018; 138:210-218. [DOI: 10.1016/j.neuropharm.2018.05.030] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 04/09/2018] [Accepted: 05/24/2018] [Indexed: 11/24/2022]
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167
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Sugaya Y, Kano M. Control of excessive neural circuit excitability and prevention of epileptic seizures by endocannabinoid signaling. Cell Mol Life Sci 2018; 75:2793-2811. [PMID: 29737364 PMCID: PMC11105219 DOI: 10.1007/s00018-018-2834-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/23/2018] [Accepted: 05/02/2018] [Indexed: 12/12/2022]
Abstract
Progress in research on endocannabinoid signaling has greatly advanced our understanding of how it controls neural circuit excitability in health and disease. In general, endocannabinoid signaling at excitatory synapses suppresses seizures by inhibiting glutamate release. In contrast, endocannabinoid signaling promotes seizures by inhibiting GABA release at inhibitory synapses. The physiological distribution of endocannabinoid signaling molecules becomes disrupted with the development of epileptic focus in patients with mesial temporal lobe epilepsy and in animal models of experimentally induced epilepsy. Augmentation of endocannabinoid signaling can promote the development of epileptic focus at initial stages. However, at later stages, increased endocannabinoid signaling delays it and suppresses spontaneous seizures. Thus, the regulation of endocannabinoid signaling at specific synapses that cause hyperexcitability during particular stages of disease development may be effective for treating epilepsy and epileptogenesis.
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Affiliation(s)
- Yuki Sugaya
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Tokyo, 113-0033, Japan
- International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo Institutes for Advanced Study (UTIAS), The University of Tokyo, Tokyo, 113-0033, Japan
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Tokyo, 113-0033, Japan.
- International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo Institutes for Advanced Study (UTIAS), The University of Tokyo, Tokyo, 113-0033, Japan.
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168
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Nozaki C, Nent E, Bilkei-Gorzo A, Zimmer A. Involvement of leptin signaling in the development of cannabinoid CB2 receptor-dependent mirror image pain. Sci Rep 2018; 8:10827. [PMID: 30018366 PMCID: PMC6050271 DOI: 10.1038/s41598-018-28507-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 06/21/2018] [Indexed: 12/17/2022] Open
Abstract
Neuropathic pain typically appears in a region innervated by an injured or diseased nerve and, in some instances, also on the contralateral side. This so-called mirror image pain is often observed in mice lacking CB2 receptors after sciatic nerve injury, but the underlying mechanisms for this phenotype largely remain unclear. Here we focused on peripheral leptin signaling, which modulates neuropathic pain development and interacts with the endocannabinoid system. Leptin production is induced at the site of nerve injury in CB2-deficient mice (CB2-KO) mice and wild type controls (WT). However, induction of leptin receptor expression was only observed in the injured nerve of CB2-KO mice. This was paralleled by a stimulation of the leptin receptor-downstream STAT3 signaling and an infiltration of F4/80-positive macrophages. Interestingly, an upregulation of leptin receptor expression STAT3 activity and macrophage infiltration was also observed on the non-injured nerve of CB2-KO mice thus reflecting the mirror image pain in CB2-KO animals. Importantly, perineurally-administered leptin-neutralizing antibodies reduced mechanical hyperalgesia, blocked mirror image pain and inhibited the recruitment of F4/80-positive macrophages. These results identify peripheral leptin signaling as an important modulator of CB2 signaling in neuropathic pain.
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Affiliation(s)
- Chihiro Nozaki
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, 53127, Bonn, Germany
| | - Elisa Nent
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, 53127, Bonn, Germany
| | - Andras Bilkei-Gorzo
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, 53127, Bonn, Germany
| | - Andreas Zimmer
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, 53127, Bonn, Germany.
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169
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Stumpf A, Parthier D, Sammons RP, Stempel AV, Breustedt J, Rost BR, Schmitz D. Cannabinoid type 2 receptors mediate a cell type-specific self-inhibition in cortical neurons. Neuropharmacology 2018; 139:217-225. [PMID: 30025920 DOI: 10.1016/j.neuropharm.2018.07.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 06/25/2018] [Accepted: 07/13/2018] [Indexed: 01/06/2023]
Abstract
Endogenous cannabinoids are diffusible lipid ligands of the main cannabinoid receptors type 1 and 2 (CB1R and CB2R). In the central nervous system endocannabinoids are produced in an activity-dependent manner and have been identified as retrograde modulators of synaptic transmission. Additionally, some neurons display a cell-autonomous slow self-inhibition (SSI) mediated by endocannabinoids. In these neurons, repetitive action potential firing triggers the production of endocannabinoids, which induce a long-lasting hyperpolarization of the membrane potential, rendering the cells less excitable. Different endocannabinoid receptors and effector mechanisms have been described underlying SSI in different cell types and brain areas. Here, we investigate SSI in neurons of layer 2/3 in the somatosensory cortex. High-frequency bursts of action potentials induced SSI in pyramidal cells (PC) and regular spiking non-pyramidal cells (RSNPC), but not in fast-spiking interneurons (FS). In RSNPCs the hyperpolarization was accompanied by a change in input resistance due to the activation of G protein-coupled inward-rectifying K+ (GIRK) channels. A CB2R-specific agonist induced the long-lasting hyperpolarization, whereas preincubation with a CB2R-specific inverse agonist suppressed SSI. Additionally, using cannabinoid receptor knockout mice, we found that SSI was still intact in CB1R-deficient but abolished in CB2R-deficient mice. Taken together, we describe an additional SSI mechanism in which the activity-induced release of endocannabinoids activates GIRK channels via CB2Rs. These findings expand our knowledge about cell type-specific differential neuronal cannabinoid receptor signaling and suggest CB2R-selective compounds as potential therapeutic approaches.
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MESH Headings
- Animals
- Cannabinoid Receptor Modulators/pharmacology
- Endocannabinoids/metabolism
- G Protein-Coupled Inwardly-Rectifying Potassium Channels/metabolism
- Membrane Potentials/drug effects
- Membrane Potentials/physiology
- Mice, Inbred C57BL
- Mice, Knockout
- Neural Inhibition/drug effects
- Neural Inhibition/physiology
- Neurons/drug effects
- Neurons/metabolism
- Receptor, Cannabinoid, CB1/deficiency
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Cannabinoid, CB2/agonists
- Receptor, Cannabinoid, CB2/deficiency
- Receptor, Cannabinoid, CB2/genetics
- Receptor, Cannabinoid, CB2/metabolism
- Somatosensory Cortex/drug effects
- Somatosensory Cortex/metabolism
- Tissue Culture Techniques
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Affiliation(s)
- Alexander Stumpf
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Germany
| | - Daniel Parthier
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Germany
| | - Rosanna P Sammons
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Germany
| | - A Vanessa Stempel
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Germany; Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, UK
| | - Jörg Breustedt
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Germany
| | - Benjamin R Rost
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Germany; German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - Dietmar Schmitz
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Germany; German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany; Berlin Institute of Health, Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, Germany; Cluster of Excellence NeuroCure, Berlin, Germany; Einstein Center for Neurosciences, Berlin, Germany.
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170
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Motor neuron development in zebrafish is altered by brief (5-hr) exposures to THC (∆ 9-tetrahydrocannabinol) or CBD (cannabidiol) during gastrulation. Sci Rep 2018; 8:10518. [PMID: 30002406 PMCID: PMC6043604 DOI: 10.1038/s41598-018-28689-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 06/26/2018] [Indexed: 12/11/2022] Open
Abstract
Marijuana is one of the most commonly used illicit recreational drugs and is widely used for medicinal purposes. The psychoactive ingredient in marijuana is ∆9-tetrahydrocannabinol (∆9-THC), whereas the major non-psychoactive ingredient is cannabidiol (CBD). Here, we exposed zebrafish embryos to ∆9-THC or CBD for 5 hours during the critical stage of development known as gastrulation. Embryos were allowed to develop normally and were examined at 2 and 5 days post fertilization. THC and CBD treated embryos exhibited reduced heart rates, axial malformations and shorter trunks. Cannabinoid treatment altered synaptic activity at neuromuscular junctions (NMJs), and fluorescent labelling of primary and secondary motor neurons indicated a change in branching patterns and a reduction in the number of axonal branches in the trunk musculature. Furthermore, there were alterations in the α-bungarotoxin labelling of nicotinic acetylcholine receptors at NMJs. Locomotion studies show that larvae exposed to THC or CBD during gastrulation exhibited drastic reductions in the number of C-start escape responses to sound stimuli, but not to touch stimuli. Together these findings indicate that zebrafish embryos exposed to ∆9-THC or CBD during the brief but critical period of gastrulation exhibited alterations in heart rate, motor neuronal morphology, synaptic activity at the NMJ and locomotor responses to sound.
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171
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Gorzkiewicz A, Szemraj J. Brain endocannabinoid signaling exhibits remarkable complexity. Brain Res Bull 2018; 142:33-46. [PMID: 29953913 DOI: 10.1016/j.brainresbull.2018.06.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 06/06/2018] [Accepted: 06/21/2018] [Indexed: 01/04/2023]
Abstract
The endocannabinoid (eCB) signaling system is one of the most extensive of the mammalian brain. Despite the involvement of only few specific ligands and receptors, the system encompasses a vast diversity of triggered mechanisms and driven effects. It mediates a wide range of phenomena, including the regulation of transmitter release, neural excitability, synaptic plasticity, impulse spread, long-term neuronal potentiation, neurogenesis, cell death, lineage segregation, cell migration, inflammation, oxidative stress, nociception and the sleep cycle. It is also known to be involved in the processes of learning and memory formation. This extensive scope of action is attained by combining numerous variables. In a properly functioning brain, the correlations of these variables are kept in a strictly controlled balance; however, this balance is disrupted in many pathological conditions. However, while this balance is known to be disrupted by drugs in the case of addicts, the stimuli and mechanisms influencing the neurodegenerating brain remain elusive. This review examines the multiple factors and phenomena affecting the eCB signaling system in the brain. It evaluates techniques of controlling the eCB system to identify the obstacles in their applications and highlights the crucial interdependent variables that may influence biomedical research outcomes.
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Affiliation(s)
- Anna Gorzkiewicz
- Medical University of Lodz, ul.Mazowiecka 6/8, 92-215, Lodz, Poland.
| | - Janusz Szemraj
- Medical University of Lodz, ul.Mazowiecka 6/8, 92-215, Lodz, Poland
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172
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Zhang J, Chen C. Alleviation of Neuropathology by Inhibition of Monoacylglycerol Lipase in APP Transgenic Mice Lacking CB2 Receptors. Mol Neurobiol 2018; 55:4802-4810. [PMID: 28733897 PMCID: PMC5776068 DOI: 10.1007/s12035-017-0689-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 07/12/2017] [Indexed: 01/25/2023]
Abstract
Inhibition of monoacylglycerol lipase (MAGL), the primary enzyme that hydrolyzes the endocannabinoid 2-arachidonoylglycerol (2-AG) in the brain, produces profound anti-inflammatory and neuroprotective effects and improves synaptic and cognitive functions in animal models of Alzheimer's disease (AD). However, the molecular mechanisms underlying the beneficial effects produced by inhibition of 2-AG metabolism are still not clear. The cannabinoid receptor type 2 (CB2R) has been thought to be a therapeutic target for AD. Here, we provide evidence, however, that CB2R does not play a role in ameliorating AD neuropathology produced by inactivation of MAGL in 5XFAD APP transgenic mice, an animal model of AD. We observed that expression of APP and β-secretase as well as production of total Aβ and Aβ42 were significantly reduced in APP transgenic mice lacking CB2R (TG-CB2-KO) treated with JZL184, a selective and potent inhibitor for MAGL. Inactivation of MAGL also alleviated neuroinflammation and neurodegeneration in TG-CB2-KO mice. Importantly, TG-CB2-KO mice treated with JZL184 still exhibited improvements in spatial learning and memory. In addition, MAGL inhibition prevented deterioration in expression of important synaptic proteins in TG-CB2-KO mice. Our results suggest that CB2R is not required in ameliorating neuropathology and preventing cognitive decline by inhibition of 2-AG metabolism in AD model animals.
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Affiliation(s)
- Jian Zhang
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite D, New Orleans, LA, 70112, USA
| | - Chu Chen
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite D, New Orleans, LA, 70112, USA.
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA.
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173
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López A, Aparicio N, Pazos MR, Grande MT, Barreda-Manso MA, Benito-Cuesta I, Vázquez C, Amores M, Ruiz-Pérez G, García-García E, Beatka M, Tolón RM, Dittel BN, Hillard CJ, Romero J. Cannabinoid CB 2 receptors in the mouse brain: relevance for Alzheimer's disease. J Neuroinflammation 2018; 15:158. [PMID: 29793509 PMCID: PMC5968596 DOI: 10.1186/s12974-018-1174-9] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/23/2018] [Indexed: 01/03/2023] Open
Abstract
Background Because of their low levels of expression and the inadequacy of current research tools, CB2 cannabinoid receptors (CB2R) have been difficult to study, particularly in the brain. This receptor is especially relevant in the context of neuroinflammation, so novel tools are needed to unveil its pathophysiological role(s). Methods We have generated a transgenic mouse model in which the expression of enhanced green fluorescent protein (EGFP) is under the control of the cnr2 gene promoter through the insertion of an Internal Ribosomal Entry Site followed by the EGFP coding region immediately 3′ of the cnr2 gene and crossed these mice with mice expressing five familial Alzheimer’s disease (AD) mutations (5xFAD). Results Expression of EGFP in control mice was below the level of detection in all regions of the central nervous system (CNS) that we examined. CB2R-dependent-EGFP expression was detected in the CNS of 3-month-old AD mice in areas of intense inflammation and amyloid deposition; expression was coincident with the appearance of plaques in the cortex, hippocampus, brain stem, and thalamus. The expression of EGFP increased as a function of plaque formation and subsequent microgliosis and was restricted to microglial cells located in close proximity to neuritic plaques. AD mice with CB2R deletion exhibited decreased neuritic plaques with no changes in IL1β expression. Conclusions Using a novel reporter mouse line, we found no evidence for CB2R expression in the healthy CNS but clear up-regulation in the context of amyloid-triggered neuroinflammation. Data from CB2R null mice indicate that they play a complex role in the response to plaque formation. Electronic supplementary material The online version of this article (10.1186/s12974-018-1174-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Alicia López
- Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón, C/ Budapest 1, 28922, Alcorcón, Madrid, Spain.,Universidad Rey Juan Carlos, Móstoles, Spain
| | - Noelia Aparicio
- Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón, C/ Budapest 1, 28922, Alcorcón, Madrid, Spain.,Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223, Pozuelo de Alarcón, Madrid, Spain
| | - M Ruth Pazos
- Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón, C/ Budapest 1, 28922, Alcorcón, Madrid, Spain.,Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223, Pozuelo de Alarcón, Madrid, Spain
| | - M Teresa Grande
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223, Pozuelo de Alarcón, Madrid, Spain
| | - M Asunción Barreda-Manso
- Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón, C/ Budapest 1, 28922, Alcorcón, Madrid, Spain.,Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223, Pozuelo de Alarcón, Madrid, Spain
| | - Irene Benito-Cuesta
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223, Pozuelo de Alarcón, Madrid, Spain
| | - Carmen Vázquez
- Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón, C/ Budapest 1, 28922, Alcorcón, Madrid, Spain
| | - Mario Amores
- Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón, C/ Budapest 1, 28922, Alcorcón, Madrid, Spain
| | - Gonzalo Ruiz-Pérez
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223, Pozuelo de Alarcón, Madrid, Spain
| | - Elena García-García
- Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón, C/ Budapest 1, 28922, Alcorcón, Madrid, Spain
| | - Margaret Beatka
- Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI, 53226, USA.,Department of Pharmacology and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Rosa M Tolón
- Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón, C/ Budapest 1, 28922, Alcorcón, Madrid, Spain.,Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223, Pozuelo de Alarcón, Madrid, Spain
| | - Bonnie N Dittel
- Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI, 53226, USA
| | - Cecilia J Hillard
- Department of Pharmacology and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Julián Romero
- Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón, C/ Budapest 1, 28922, Alcorcón, Madrid, Spain. .,Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223, Pozuelo de Alarcón, Madrid, Spain.
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174
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Tang M, Cao X, Zhang K, Li Y, Zheng QY, Li GQ, He QH, Li SJ, Xu GL, Zhang KQ. Celastrol alleviates renal fibrosis by upregulating cannabinoid receptor 2 expression. Cell Death Dis 2018; 9:601. [PMID: 29789558 PMCID: PMC5964092 DOI: 10.1038/s41419-018-0666-y] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 04/24/2018] [Accepted: 05/04/2018] [Indexed: 12/31/2022]
Abstract
Renal fibrosis is the final manifestation of various chronic kidney diseases, and no effective therapy is available to prevent or reverse it. Celastrol, a triterpene that derived from traditional Chinese medicine, is a known potent anti-fibrotic agent. However, the underlying mechanisms of action of celastrol on renal fibrosis remain unknown. In this study, we found that celastrol treatment remarkably attenuated unilateral ureteral obstruction (UUO)-induced mouse renal fibrosis. This was evidenced by the significant reduction in tubular injury; collagen deposition; accumulation of fibronectin, collagen I, and α-smooth muscle actin; and the expression levels of pro-fibrotic factors Vim, Cola1, and TGF-β1 mRNA, as well as inflammatory responses. Celastrol showed similar effects in a folic acid-induced mouse renal fibrosis model. Furthermore, celastrol potentiated the expression of the anti-fibrotic factor cannabinoid receptor 2 (CB2R) in established mouse fibrotic kidney tissues and transforming growth factor β1 (TGF-β1)-stimulated human kidney 2 (HK-2) cells. In addition, the CB2R antagonist (SR144528) abolished celastrol-mediated beneficial effects on renal fibrosis. Moreover, UUO- or TGF-β1-induced activation of the pro-fibrotic factor SMAD family member 3 (Smad3) was markedly inhibited by celastrol. Inhibition of Smad3 activation by an inhibitor (SIS3) markedly reduced TGF-β1-induced downregulation of CB2R expression. In conclusion, our study provides the first direct evidence that celastrol significantly alleviated renal fibrosis, by contributing to the upregulation of CB2R expression through inhibiting Smad3 signaling pathway activation. Therefore, celastrol could be a potential drug for treating patients with renal fibrosis.
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Affiliation(s)
- Ming Tang
- Department of Nephrology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China.,Department of Immunology, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Xu Cao
- Department of Nephrology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Kun Zhang
- Department of Nephrology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - You Li
- Department of Nephrology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Quan-You Zheng
- Department of Nephrology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Gui-Qing Li
- Department of Immunology, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Qian-Hui He
- Department of Nephrology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Shu-Jing Li
- Department of Nephrology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Gui-Lian Xu
- Department of Immunology, Army Medical University (Third Military Medical University), Chongqing, 400038, China.
| | - Ke-Qin Zhang
- Department of Nephrology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China.
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175
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Lavanco G, Castelli V, Brancato A, Tringali G, Plescia F, Cannizzaro C. The endocannabinoid-alcohol crosstalk: Recent advances on a bi-faceted target. Clin Exp Pharmacol Physiol 2018; 45:889-896. [PMID: 29770478 DOI: 10.1111/1440-1681.12967] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 05/04/2018] [Accepted: 05/07/2018] [Indexed: 12/22/2022]
Abstract
Increasing evidence has focusesed on the endocannabinoid system as a relevant player in the induction of aberrant synaptic plasticity and related addictive phenotype following chronic excessive alcohol drinking. In addition, the endocannabinoid system is implicated in the pathogenesis of alcoholic liver disease. Interestingly, whereas the involvement of CB1 receptors in alcohol rewarding properties is established, the central and peripheral action of CB2 signalling is still to be elucidated. This review aims at giving the input to deepen knowledge on the role of the endocannabinoid system, highlighting the advancing evidence that suggests that CB1 and CB2 receptors may play opposite roles in the regulation of both the reinforcing properties of alcohol in the brain and the mechanisms responsible for cell injury and inflammation in the hepatic tissue. The manipulation of the endocannabinoid system could represent a bi-faceted strategy to counteract alcohol-related dysfunction in central transmission and liver structural and functional disarrangement.
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Affiliation(s)
- Gianluca Lavanco
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Valentina Castelli
- Department of Sciences for Health Promotion and Mother and Child Care "Giuseppe D'Alessandro", University of Palermo, Palermo, Italy
| | - Anna Brancato
- Department of Sciences for Health Promotion and Mother and Child Care "Giuseppe D'Alessandro", University of Palermo, Palermo, Italy
| | - Giuseppe Tringali
- Institute of Pharmacology, Catholic University School of Medicine, Rome, Italy
| | - Fulvio Plescia
- Department of Sciences for Health Promotion and Mother and Child Care "Giuseppe D'Alessandro", University of Palermo, Palermo, Italy
| | - Carla Cannizzaro
- Department of Sciences for Health Promotion and Mother and Child Care "Giuseppe D'Alessandro", University of Palermo, Palermo, Italy
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176
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Navarrete F, García-Gutiérrez MS, Aracil-Fernández A, Lanciego JL, Manzanares J. Cannabinoid CB1 and CB2 Receptors, and Monoacylglycerol Lipase Gene Expression Alterations in the Basal Ganglia of Patients with Parkinson's Disease. Neurotherapeutics 2018; 15:459-469. [PMID: 29352424 PMCID: PMC5935636 DOI: 10.1007/s13311-018-0603-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Previous studies suggest that the endocannabinoid system plays an important role in the neuropathological basis of Parkinson's disease (PD). This study was designed to detect potential alterations in the cannabinoid receptors CB1 (CB1r) and CB2 (A isoform, CB2Ar), and in monoacylglycerol lipase (MAGL) gene expression in the substantia nigra (SN) and putamen (PUT) of patients with PD. Immunohistochemical studies were performed to identify precise CB2r cellular localization in the SN of control and PD patients. To ensure the validity and reliability of gene expression data, the RNA integrity number (RIN) was calculated. CB1r, CB2Ar, and MAGL gene expressions were evaluated by real-time polymerase chain reaction (real-time PCR) using Taqman assays. Immunohistochemical experiments with in situ proximity ligation assay (PLA) were used to detect the precise cellular localization of CB2r in neurons, astrocytes, and/or microglia. All RIN values from control and PD postmortem brain samples were > 6. CB1r gene expression was unchanged in the SN but significantly higher in the PUT of patients with PD. CB2Ar gene expression was significantly increased (4-fold) in the SN but decreased in the PUT, whereas MAGL gene expression was decreased in the SN and increased in the PUT. Immunohistochemical analyses revealed that CB2r co-localize with astrocytes but not with neurons or microglial cells in the SN. The results of the present study suggest that CB1r, CB2r, and MAGL are closely related to the neuropathological processes of PD. Therefore, the pharmacological modulation of these targets could represent a new potential therapeutic tool for the management of PD.
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Affiliation(s)
- Francisco Navarrete
- Instituto de Neurociencias, Miguel Hernández University-CSIC, San Juan de Alicante, Alicante, Spain
- Red de Trastornos Adictivos, Instituto de Salud Carlos III, MICINN and FEDER, Madrid, Spain
| | - M Salud García-Gutiérrez
- Instituto de Neurociencias, Miguel Hernández University-CSIC, San Juan de Alicante, Alicante, Spain
- Red de Trastornos Adictivos, Instituto de Salud Carlos III, MICINN and FEDER, Madrid, Spain
| | - Auxiliadora Aracil-Fernández
- Instituto de Neurociencias, Miguel Hernández University-CSIC, San Juan de Alicante, Alicante, Spain
- Red de Trastornos Adictivos, Instituto de Salud Carlos III, MICINN and FEDER, Madrid, Spain
| | - José L Lanciego
- Centro de Investigación Médica Aplicada, División de Neurociencias (CIMA-CIBERNED), Universidad de Navarra, Pamplona, Spain
| | - Jorge Manzanares
- Instituto de Neurociencias, Miguel Hernández University-CSIC, San Juan de Alicante, Alicante, Spain.
- Red de Trastornos Adictivos, Instituto de Salud Carlos III, MICINN and FEDER, Madrid, Spain.
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177
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Labra VC, Santibáñez CA, Gajardo-Gómez R, Díaz EF, Gómez GI, Orellana JA. The Neuroglial Dialog Between Cannabinoids and Hemichannels. Front Mol Neurosci 2018; 11:79. [PMID: 29662436 PMCID: PMC5890195 DOI: 10.3389/fnmol.2018.00079] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 02/28/2018] [Indexed: 12/11/2022] Open
Abstract
The formation of gap junctions was initially thought to be the central role of connexins, however, recent evidence had brought to light the high relevance of unopposed hemichannels as an independent mechanism for the selective release of biomolecules during physiological and pathological conditions. In the healthy brain, the physiological opening of astrocyte hemichannels modulates basal excitatory synaptic transmission. At the other end, the release of potentially neurotoxic compounds through astroglial hemichannels and pannexons has been insinuated as one of the functional alterations that negatively affect the progression of multiple brain diseases. Recent insights in this matter have suggested encannabinoids (eCBs) as molecules that could regulate the opening of these channels during diverse conditions. In this review, we discuss and hypothesize the possible interplay between the eCB system and the hemichannel/pannexon-mediated signaling in the inflamed brain and during event of synaptic plasticity. Most findings indicate that eCBs seem to counteract the activation of major neuroinflammatory pathways that lead to glia-mediated production of TNF-α and IL-1β, both well-known triggers of astroglial hemichannel opening. In contrast to the latter, in the normal brain, eCBs apparently elicit the Ca2+-activation of astrocyte hemichannels, which could have significant consequences on eCB-dependent synaptic plasticity.
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Affiliation(s)
- Valeria C Labra
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| | - Cristian A Santibáñez
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| | - Rosario Gajardo-Gómez
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| | - Esteban F Díaz
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| | - Gonzalo I Gómez
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| | - Juan A Orellana
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
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178
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Tchekalarova J, da Conceição Machado K, Gomes Júnior AL, de Carvalho Melo Cavalcante AA, Momchilova A, Tzoneva R. Pharmacological characterization of the cannabinoid receptor 2 agonist, β-caryophyllene on seizure models in mice. Seizure 2018; 57:22-26. [PMID: 29547827 DOI: 10.1016/j.seizure.2018.03.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 02/19/2018] [Accepted: 03/09/2018] [Indexed: 01/18/2023] Open
Abstract
PURPOSE Activation of CB1 receptors, produces anticonvulsant effect accompanied by memory disturbance both in animal seizure tests and in patients with epilepsy. Few reports considered the role of CB2 receptor on seizure susceptibility and cognitive functions. The aim of the present study was to explore the effect of a selective CB2 receptor agonist β-caryophyllene (BCP) in models of seizures and cognition in mice. METHODS Dose-dependent effects of BCP was studied in maximal electroshock seizure (MES) test, subcutaneous pentylenetetrazole (scPTZ) test and Morris water maze test. Phenytoin and diazepam were used as reference drugs in seizure tests. The effect of sub-chronic treatment with BCP for 7 days (50 and 100 mg kg-1) was assessed on status epilepticus (SE) induced by kainic acid (KA) model and oxidative stress through measurement of malondialdehyde (MDA) level in the hippocampus. The acute neurotoxicity was determined by a rotarod test. RESULTS The BCP exerted a protection in the MES test at the lowest dose of 30 mg kg-1 at the 4-h interval tested comparable to that of the referent drug phenytoin. The CB2 agonist was ineffective in the scPTZ test. The BCP displayed no neurotoxicity in the rotarod test. The BCP decreased the seizure scores in the KA-induced SE, which effect correlated with a diminished lipid peroxidation. The CB2 agonist exerted a dose-dependent decrease of latency to cross the target area during the three days of testing in the Morris water maze test. CONCLUSION Our results suggest that the CB2 receptor agonists might be clinically useful as an adjunct treatment against seizure spread and status epilepticus and concomitant oxidative stress, neurotoxicity and cognitive impairments.
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Affiliation(s)
- Jana Tchekalarova
- Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 23, Sofia, 1113, Bulgaria.
| | - Keylla da Conceição Machado
- Laboratory of Research in Experimental Neurochemistry of the Postgraduate Program in Pharmaceutical Sciences, Federal University of Piauí, Teresina, Brazil; Laboratory of Research in Toxicological Genetics of the Post-Graduate Program in Pharmaceutical Sciences, Federal University of Piauí, Teresina, Brazil
| | - Antonio Luiz Gomes Júnior
- Laboratory of Research in Experimental Neurochemistry of the Postgraduate Program in Pharmaceutical Sciences, Federal University of Piauí, Teresina, Brazil; Laboratory of Research in Toxicological Genetics of the Post-Graduate Program in Pharmaceutical Sciences, Federal University of Piauí, Teresina, Brazil
| | | | - Albena Momchilova
- Institute of Biophysics and Biomedical Engineering, BAS, Sofia, Bulgaria
| | - Rumyana Tzoneva
- Institute of Biophysics and Biomedical Engineering, BAS, Sofia, Bulgaria
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179
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Spinelli F, Mu L, Ametamey SM. Radioligands for positron emission tomography imaging of cannabinoid type 2 receptor. J Labelled Comp Radiopharm 2017; 61:299-308. [PMID: 29110331 DOI: 10.1002/jlcr.3579] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 10/10/2017] [Accepted: 10/24/2017] [Indexed: 01/11/2023]
Abstract
The cannabinoid type 2 (CB2) receptor is an immunomodulatory receptor mainly expressed in peripheral cells and organs of the immune system. The expression level of CB2 in the central nervous system under physiological conditions is negligible, however under neuroinflammatory conditions an upregulation of CB2 protein or mRNA mainly colocalized with activated microglial cells has been reported. Consequently, CB2 agonists have been confirmed to play a role in neuroprotective and anti-inflammatory processes. A suitable positron emission tomography radioligand for imaging CB2 would provide an invaluable research tool to explore the role of CB2 receptor expression in inflammatory disorders. In this review, we provide a summary of so far published CB2 radioligands as well as their in vitro and in vivo binding characteristics.
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Affiliation(s)
- Francesco Spinelli
- Department of Pharmacy-Pharmaceutical Sciences, University of Bari "A. Moro", Bari, Italy.,Department of Chemistry and Applied Biosciences, Center for Radiopharmaceutical Sciences of ETH-PSI-USZ, Institute of Pharmaceutical Sciences, ETH Zurich, Zurich, Switzerland
| | - Linjing Mu
- Department of Nuclear Medicine, Center for Radiopharmaceutical Sciences of ETH-PSI-USZ, University Hospital Zurich, Zurich, Switzerland
| | - Simon M Ametamey
- Department of Chemistry and Applied Biosciences, Center for Radiopharmaceutical Sciences of ETH-PSI-USZ, Institute of Pharmaceutical Sciences, ETH Zurich, Zurich, Switzerland
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180
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Scarante FF, Vila-Verde C, Detoni VL, Ferreira-Junior NC, Guimarães FS, Campos AC. Cannabinoid Modulation of the Stressed Hippocampus. Front Mol Neurosci 2017; 10:411. [PMID: 29311804 PMCID: PMC5742214 DOI: 10.3389/fnmol.2017.00411] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 11/27/2017] [Indexed: 12/31/2022] Open
Abstract
Exposure to stressful situations is one of the risk factors for the precipitation of several psychiatric disorders, including Major Depressive Disorder, Posttraumatic Stress Disorder and Schizophrenia. The hippocampal formation is a forebrain structure highly associated with emotional, learning and memory processes; being particularly vulnerable to stress. Exposure to stressful stimuli leads to neuroplastic changes and imbalance between inhibitory/excitatory networks. These changes have been associated with an impaired hippocampal function. Endocannabinoids (eCB) are one of the main systems controlling both excitatory and inhibitory neurotransmission, as well as neuroplasticity within the hippocampus. Cannabinoids receptors are highly expressed in the hippocampus, and several lines of evidence suggest that facilitation of cannabinoid signaling within this brain region prevents stress-induced behavioral changes. Also, chronic stress modulates hippocampal CB1 receptors expression and endocannabinoid levels. Moreover, cannabinoids participate in mechanisms related to synaptic plasticity and adult neurogenesis. Here, we discussed the main findings supporting the involvement of hippocampal cannabinoid neurotransmission in stress-induced behavioral and neuroplastic changes.
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Affiliation(s)
- Franciele F Scarante
- Department of Pharmacology, School of Medicine of Ribeirão Preto, Centre for Interdisciplinary Research on Applied Neurosciences (NAPNA), Cannabinoid Research Institute, University of São Paulo, São Paulo, Brazil
| | - Carla Vila-Verde
- Department of Pharmacology, School of Medicine of Ribeirão Preto, Centre for Interdisciplinary Research on Applied Neurosciences (NAPNA), Cannabinoid Research Institute, University of São Paulo, São Paulo, Brazil
| | - Vinícius L Detoni
- Department of Pharmacology, School of Medicine of Ribeirão Preto, Centre for Interdisciplinary Research on Applied Neurosciences (NAPNA), Cannabinoid Research Institute, University of São Paulo, São Paulo, Brazil
| | - Nilson C Ferreira-Junior
- Department of Pharmacology, School of Medicine of Ribeirão Preto, Centre for Interdisciplinary Research on Applied Neurosciences (NAPNA), Cannabinoid Research Institute, University of São Paulo, São Paulo, Brazil
| | - Francisco S Guimarães
- Department of Pharmacology, School of Medicine of Ribeirão Preto, Centre for Interdisciplinary Research on Applied Neurosciences (NAPNA), Cannabinoid Research Institute, University of São Paulo, São Paulo, Brazil
| | - Alline C Campos
- Department of Pharmacology, School of Medicine of Ribeirão Preto, Centre for Interdisciplinary Research on Applied Neurosciences (NAPNA), Cannabinoid Research Institute, University of São Paulo, São Paulo, Brazil
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181
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Liu QR, Canseco-Alba A, Zhang HY, Tagliaferro P, Chung M, Dennis E, Sanabria B, Schanz N, Escosteguy-Neto JC, Ishiguro H, Lin Z, Sgro S, Leonard CM, Santos-Junior JG, Gardner EL, Egan JM, Lee JW, Xi ZX, Onaivi ES. Cannabinoid type 2 receptors in dopamine neurons inhibits psychomotor behaviors, alters anxiety, depression and alcohol preference. Sci Rep 2017; 7:17410. [PMID: 29234141 PMCID: PMC5727179 DOI: 10.1038/s41598-017-17796-y] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 11/30/2017] [Indexed: 12/31/2022] Open
Abstract
Cannabinoid CB2 receptors (CB2Rs) are expressed in mouse brain dopamine (DA) neurons and are involved in several DA-related disorders. However, the cell type-specific mechanisms are unclear since the CB2R gene knockout mice are constitutive gene knockout. Therefore, we generated Cnr2-floxed mice that were crossed with DAT-Cre mice, in which Cre- recombinase expression is under dopamine transporter gene (DAT) promoter control to ablate Cnr2 gene in midbrain DA neurons of DAT-Cnr2 conditional knockout (cKO) mice. Using a novel sensitive RNAscope in situ hybridization, we detected CB2R mRNA expression in VTA DA neurons in wildtype and DAT-Cnr2 cKO heterozygous but not in the homozygous DAT-Cnr2 cKO mice. Here we report that the deletion of CB2Rs in dopamine neurons enhances motor activities, modulates anxiety and depression-like behaviors and reduces the rewarding properties of alcohol. Our data reveals that CB2Rs are involved in the tetrad assay induced by cannabinoids which had been associated with CB1R agonism. GWAS studies indicates that the CNR2 gene is associated with Parkinson's disease and substance use disorders. These results suggest that CB2Rs in dopaminergic neurons may play important roles in the modulation of psychomotor behaviors, anxiety, depression, and pain sensation and in the rewarding effects of alcohol and cocaine.
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Affiliation(s)
- Qing-Rong Liu
- Department of Biology, William Paterson University, Wayne, New Jersey, 74070, USA.
- Laboratory of Clinical Investigation, national Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA.
| | - Ana Canseco-Alba
- Department of Biology, William Paterson University, Wayne, New Jersey, 74070, USA
| | - Hai-Ying Zhang
- Molecular Targets and medications Discovery Branch, Intramural Research Program. National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - Patricia Tagliaferro
- Department of Biology, William Paterson University, Wayne, New Jersey, 74070, USA
| | - Monika Chung
- Department of Biology, William Paterson University, Wayne, New Jersey, 74070, USA
| | - Eugene Dennis
- Department of Biology, William Paterson University, Wayne, New Jersey, 74070, USA
| | - Branden Sanabria
- Department of Biology, William Paterson University, Wayne, New Jersey, 74070, USA
| | - Norman Schanz
- Department of Biology, William Paterson University, Wayne, New Jersey, 74070, USA
| | | | - Hiroki Ishiguro
- Department of Psychiatry, University of Yamanashi, Yamanashi, Japan
| | - Zhicheng Lin
- Department of Psychiatry, Harvard Medical School, Psychiatric Neurogenomics, Division of Alcohol and Drug Abuse, and Mailman Neuroscience Research Center, McLean Hospital, Belmont, MA, USA
| | - Susan Sgro
- Department of Biology, William Paterson University, Wayne, New Jersey, 74070, USA
| | - Claire M Leonard
- Department of Biology, William Paterson University, Wayne, New Jersey, 74070, USA
| | | | - Eliot L Gardner
- Molecular Targets and medications Discovery Branch, Intramural Research Program. National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - Josephine M Egan
- Laboratory of Clinical Investigation, national Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Jeung Woon Lee
- Department of Biology, William Paterson University, Wayne, New Jersey, 74070, USA
| | - Zheng-Xiong Xi
- Molecular Targets and medications Discovery Branch, Intramural Research Program. National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - Emmanuel S Onaivi
- Department of Biology, William Paterson University, Wayne, New Jersey, 74070, USA.
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182
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Rowley S, Sun X, Lima IV, Tavenier A, de Oliveira ACP, Dey SK, Danzer SC. Cannabinoid receptor 1/2 double-knockout mice develop epilepsy. Epilepsia 2017; 58:e162-e166. [PMID: 29105060 DOI: 10.1111/epi.13930] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2017] [Indexed: 12/20/2022]
Abstract
The endocannabinoid system has gained attention as an important modulator of activity in the central nervous system. Initial studies focused on cannabinoid receptor 1 (CB1), which is widely expressed in the brain, but recent work also implicates cannabinoid receptor 2 (CB2) in modulating neuronal activity. Both receptors are capable of reducing neuronal activity, generating interest in cannabinoid receptor agonists as potential anticonvulsants. CB1 (Cnr1) and CB2 (Cnr2) single-knockout mice have been generated, with the former showing heightened seizure sensitivity, but not overt seizures. Given overlapping and complementary functions of CB1 and CB2 receptors, we queried whether double-knockout mice would show an exacerbated neurological phenotype. Strikingly, 30% of double-knockout mice exhibited provoked behavioral seizures, and 80% were found to be epileptic following 24/7 video-electroencephalographic monitoring. Single-knockout animals did not exhibit seizures. These findings highlight the importance of the endocannabinoid system for maintaining network stability.
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Affiliation(s)
- Shane Rowley
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A
| | - Xiaofei Sun
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A
| | - Isabel V Lima
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A.,Department of Pharmacology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Alexandra Tavenier
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A
| | | | - Sudhansu K Dey
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A
| | - Steve C Danzer
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A.,Departments of Anesthesia and Pediatrics, University of Cincinnati, Cincinnati, Ohio, U.S.A
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183
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Li Y, Kim J. Distinct roles of neuronal and microglial CB2 cannabinoid receptors in the mouse hippocampus. Neuroscience 2017; 363:11-25. [PMID: 28888955 DOI: 10.1016/j.neuroscience.2017.08.053] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 08/06/2017] [Accepted: 08/29/2017] [Indexed: 01/03/2023]
Abstract
The effects of cannabinoids are primarily mediated by type-1 cannabinoid receptors in the brain and type-2 cannabinoid receptors (CB2Rs) in the peripheral immune system. However, recent evidence demonstrates that CB2Rs are also expressed in the brain and implicated in neuropsychiatric effects. Diverse types of cells in various regions in the brain express CB2Rs but the cellular loci of CB2Rs that induce specific behavioral effects have not been determined. To manipulate CB2R expression in specific types of cells in the dorsal hippocampus of adult mice, we used Cre-dependent overexpression and CRISPR-Cas9 genome-editing techniques in combination with adeno-associated viruses and transgenic mice. Elevation and disruption of CB2R expression in microglia in the CA1 area increased and decreased, respectively, contextual fear memory. In CA1 pyramidal neurons, disruption of CB2R expression enhanced spatial working memory, whereas their overexpression reduced anxiety levels assessed asan increase in the exploration time in the central area of open field. Interneuronal CB2Rs were not involved in the modulation of cognitive or emotional behaviors tested in this study. The targeted manipulation of CB2R expression in pyramidal neurons and microglia suggests that CB2Rs in different types of cells in the mature hippocampus play distinct roles in the regulation of memory and anxiety.
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Affiliation(s)
- Yong Li
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA.
| | - Jimok Kim
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; Department of Neurology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
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184
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Abnormalities in Dynamic Brain Activity Caused by Mild Traumatic Brain Injury Are Partially Rescued by the Cannabinoid Type-2 Receptor Inverse Agonist SMM-189. eNeuro 2017; 4:eN-NWR-0387-16. [PMID: 28828401 PMCID: PMC5562300 DOI: 10.1523/eneuro.0387-16.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 06/26/2017] [Accepted: 07/03/2017] [Indexed: 12/23/2022] Open
Abstract
Mild traumatic brain injury (mTBI) can cause severe long-term cognitive and emotional deficits, including impaired memory, depression, and persevering fear, but the neuropathological basis of these deficits is uncertain. As medial prefrontal cortex (mPFC) and hippocampus play important roles in memory and emotion, we used multi-site, multi-electrode recordings of oscillatory neuronal activity in local field potentials (LFPs) in awake, head-fixed mice to determine if the functioning of these regions was abnormal after mTBI, using a closed-skull focal cranial blast model. We evaluated mPFC, hippocampus CA1, and primary somatosensory/visual cortical areas (S1/V1). Although mTBI did not alter the power of oscillations, it did cause increased coherence of θ (4-10 Hz) and β (10-30 Hz) oscillations within mPFC and S1/V1, reduced CA1 sharp-wave ripple (SWR)-evoked LFP activity in mPFC, downshifted SWR frequencies in CA1, and enhanced θ-γ phase-amplitude coupling (PAC) within mPFC. These abnormalities might be linked to the impaired memory, depression, and persevering fear seen after mTBI. Treatment with the cannabinoid type-2 (CB2) receptor inverse agonist SMM-189 has been shown to mitigate functional deficits and neuronal injury after mTBI in mice. We found that SMM-189 also reversed most of the observed neurophysiological abnormalities. This neurophysiological rescue is likely to stem from the previously reported reduction in neuron loss and/or the preservation of neuronal function and connectivity resulting from SMM-189 treatment, which appears to stem from the biasing of microglia from the proinflammatory M1 state to the prohealing M2 state by SMM-189.
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185
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Abstract
The function of the CB2 cannabinoid receptor in the brain has long been a matter of debate. In this issue of Neuron, Stempel et al. (2016) describe a mechanism whereby endocannabinoid production leads to a cell-intrinsic hyperpolarization that controls self activity.
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Affiliation(s)
- Salma A Quraishi
- Department of Biology, UTSA Neurosciences Institute, University of Texas at San Antonio, San Antonio, TX, 78249, USA.
| | - Carlos A Paladini
- Department of Biology, UTSA Neurosciences Institute, University of Texas at San Antonio, San Antonio, TX, 78249, USA.
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186
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Huizenga MN, Wicker E, Beck VC, Forcelli PA. Anticonvulsant effect of cannabinoid receptor agonists in models of seizures in developing rats. Epilepsia 2017; 58:1593-1602. [PMID: 28691158 DOI: 10.1111/epi.13842] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2017] [Indexed: 01/07/2023]
Abstract
OBJECTIVE Although drugs targeting the cannabinoid system (e.g., CB1 receptor agonists) display anticonvulsant efficacy in adult animal models of seizures/epilepsy, they remain unexplored in developing animal models. However, cannabinoid system functions emerge early in development, providing a rationale for targeting this system in neonates. We examined the therapeutic potential of drugs targeting the cannabinoid system in three seizure models in developing rats. METHODS Postnatal day (P) 10, Sprague-Dawley rat pups were challenged with the chemoconvulsant methyl-6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate (DMCM) or pentylenetetrazole (PTZ), after treatment with either CB1/2 mixed agonist (WIN 55,212-2), CB1 agonist (arachidonyl-2'-chloroethylamide [ACEA]), CB2 agonist (HU-308), CB1 antagonist (AM-251), CB2 antagonist (AM-630), fatty acid amide hydrolase inhibitor (URB-597), or G protein-coupled receptor 55 agonist (O-1602). P20 Sprague-Dawley pups were challenged with DMCM after treatment with WIN, ACEA, or URB. Finally, after pretreatment with WIN, P10 Sprague-Dawley rats were challenged against acute hypoxia-induced seizures. RESULTS The mixed CB1/2 agonist and the CB1-specific agonist, but no other drugs, displayed anticonvulsant effects against clonic seizures in the DMCM model. By contrast, both CB1 and CB2 antagonism increased seizure severity. Similarly, we found that the CB1/2 agonist displayed antiseizure efficacy against acute hypoxia-induced seizures (automatisms, clonic and tonic-clonic seizures) and tonic-clonic seizures evoked by PTZ. Anticonvulsant effects were seen in P10 animals but not P20 animals. SIGNIFICANCE Early life seizures represent a significant cause of morbidity, with 30-40% of infants and children with epilepsy failing to achieve seizure remission with current pharmacotherapy. Identification of new therapies for neonatal/infantile epilepsy syndromes is thus of high priority. These data indicate that the anticonvulsant action of the CB system is specific to CB1 receptor activation during early development and provide justification for further examination of CB1 receptor agonists as novel antiepileptic drugs targeting epilepsy in infants and children.
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Affiliation(s)
- Megan N Huizenga
- Pharmacology & Physiology, Georgetown University, Washington, District of Columbia, U.S.A
| | - Evan Wicker
- Pharmacology & Physiology, Georgetown University, Washington, District of Columbia, U.S.A
| | - Veronica C Beck
- Pharmacology & Physiology, Georgetown University, Washington, District of Columbia, U.S.A
| | - Patrick A Forcelli
- Pharmacology & Physiology, Georgetown University, Washington, District of Columbia, U.S.A.,Neuroscience, Georgetown University, Washington, District of Columbia, U.S.A.,Interdisciplinary Program in Neuroscience, Georgetown University, Washington, District of Columbia, U.S.A
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187
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Ruggiero RN, Rossignoli MT, De Ross JB, Hallak JEC, Leite JP, Bueno-Junior LS. Cannabinoids and Vanilloids in Schizophrenia: Neurophysiological Evidence and Directions for Basic Research. Front Pharmacol 2017; 8:399. [PMID: 28680405 PMCID: PMC5478733 DOI: 10.3389/fphar.2017.00399] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 06/06/2017] [Indexed: 01/14/2023] Open
Abstract
Much of our knowledge of the endocannabinoid system in schizophrenia comes from behavioral measures in rodents, like prepulse inhibition of the acoustic startle and open-field locomotion, which are commonly used along with neurochemical approaches or drug challenge designs. Such methods continue to map fundamental mechanisms of sensorimotor gating, hyperlocomotion, social interaction, and underlying monoaminergic, glutamatergic, and GABAergic disturbances. These strategies will require, however, a greater use of neurophysiological tools to better inform clinical research. In this sense, electrophysiology and viral vector-based circuit dissection, like optogenetics, can further elucidate how exogenous cannabinoids worsen (e.g., tetrahydrocannabinol, THC) or ameliorate (e.g., cannabidiol, CBD) schizophrenia symptoms, like hallucinations, delusions, and cognitive deficits. Also, recent studies point to a complex endocannabinoid-endovanilloid interplay, including the influence of anandamide (endogenous CB1 and TRPV1 agonist) on cognitive variables, such as aversive memory extinction. In fact, growing interest has been devoted to TRPV1 receptors as promising therapeutic targets. Here, these issues are reviewed with an emphasis on the neurophysiological evidence. First, we contextualize imaging and electrographic findings in humans. Then, we present a comprehensive review on rodent electrophysiology. Finally, we discuss how basic research will benefit from further combining psychopharmacological and neurophysiological tools.
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Affiliation(s)
- Rafael N Ruggiero
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São PauloRibeirão Preto, Brazil
| | - Matheus T Rossignoli
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São PauloRibeirão Preto, Brazil
| | - Jana B De Ross
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São PauloRibeirão Preto, Brazil
| | - Jaime E C Hallak
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São PauloRibeirão Preto, Brazil.,National Institute for Science and Technology-Translational Medicine, National Council for Scientific and Technological Development (CNPq)Ribeirão Preto, Brazil
| | - Joao P Leite
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São PauloRibeirão Preto, Brazil
| | - Lezio S Bueno-Junior
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São PauloRibeirão Preto, Brazil
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188
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Araque A, Castillo PE, Manzoni OJ, Tonini R. Synaptic functions of endocannabinoid signaling in health and disease. Neuropharmacology 2017. [PMID: 28625718 DOI: 10.1016/j.neuropharm.2017.06.017] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Endocannabinoids (eCBs) are a family of lipid molecules that act as key regulators of synaptic transmission and plasticity. They are synthetized "on demand" following physiological and/or pathological stimuli. Once released from postsynaptic neurons, eCBs typically act as retrograde messengers to activate presynaptic type 1 cannabinoid receptors (CB1) and induce short- or long-term depression of neurotransmitter release. Besides this canonical mechanism of action, recent findings have revealed a number of less conventional mechanisms by which eCBs regulate neural activity and synaptic function, suggesting that eCB-mediated plasticity is mechanistically more diverse than anticipated. These mechanisms include non-retrograde signaling, signaling via astrocytes, participation in long-term potentiation, and the involvement of mitochondrial CB1. Focusing on paradigmatic brain areas, such as hippocampus, striatum, and neocortex, we review typical and novel signaling mechanisms, and discuss the functional implications in normal brain function and brain diseases. In summary, eCB signaling may lead to different forms of synaptic plasticity through activation of a plethora of mechanisms, which provide further complexity to the functional consequences of eCB signaling. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".
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Affiliation(s)
- Alfonso Araque
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA.
| | - Olivier J Manzoni
- Institut National de la Santé et et de la Recherche Médicale U901 Marseille, France, Université de la Méditerranée UMR S901 Aix-Marseille Marseille, France, INMED Marseille, France.
| | - Raffaella Tonini
- Neuroscience and Brain Technologies Department, Istituto Italiano di Tecnologia, Genova, Italy.
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189
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Wu J, Hocevar M, Foss JF, Bie B, Naguib M. Activation of CB 2 receptor system restores cognitive capacity and hippocampal Sox2 expression in a transgenic mouse model of Alzheimer's disease. Eur J Pharmacol 2017; 811:12-20. [PMID: 28551012 DOI: 10.1016/j.ejphar.2017.05.044] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 05/17/2017] [Accepted: 05/24/2017] [Indexed: 01/21/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by neuroinflammation, extensive deposits of amyloid-β aggregates, and loss of memory and cognitive abilities. The brains of patients with AD show increased expression of cannabinoid receptor type 2 (CB2) receptors and glial markers. CB2 receptors act as a negative feedback regulator; when activated by a CB2 agonist, they can help limit the extent of the neuroinflammatory response and the subsequent development of neuronal damage in the central nervous system. In a double transgenic APP/PS1 mice model of AD, we evaluated the effect of MDA7, a CB2 agonist, on several neuropathological conditions of AD including amyloid deposition, inflammatory reaction, Sox2 (sex-determining region Y-box 2) expression, and spatial memory. Activation of microglia CB2 receptors by MDA7 suppressed neuroinflammation, demonstrated by decreased immunosignal of Iba1 in the hippocampal CA1 and dentate gyrus (DG) areas, promoted clearance of amyloid plaques in the DG area, restored Sox2 expression, and promoted recovery of the neuronal synaptic plasticity in hippocampal CA1. In addition, treatment with MDA7 improved the behavioral performance in the Morris water maze in APP/PS1mice. Collectively, these findings suggest that MDA7 has a potential therapeutic effect in the setting of AD.
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Affiliation(s)
- Jiang Wu
- Anesthesiology Institute, Cleveland Clinic, 9500 Euclid Ave. - NE6-306, Cleveland, OH 44195, USA
| | - Mark Hocevar
- Anesthesiology Institute, Cleveland Clinic, 9500 Euclid Ave. - NE6-306, Cleveland, OH 44195, USA; Medical student, Brown University, Providence, RI 02912, USA
| | - Joseph F Foss
- Anesthesiology Institute, Cleveland Clinic, 9500 Euclid Ave. - NE6-306, Cleveland, OH 44195, USA
| | - Bihua Bie
- Anesthesiology Institute, Cleveland Clinic, 9500 Euclid Ave. - NE6-306, Cleveland, OH 44195, USA
| | - Mohamed Naguib
- Anesthesiology Institute, Cleveland Clinic, 9500 Euclid Ave. - NE6-306, Cleveland, OH 44195, USA.
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190
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Pharmacology of cannabinoids in the treatment of epilepsy. Epilepsy Behav 2017; 70:313-318. [PMID: 28087250 DOI: 10.1016/j.yebeh.2016.11.016] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 11/09/2016] [Accepted: 11/11/2016] [Indexed: 01/01/2023]
Abstract
The use of cannabis products in the treatment of epilepsy has long been of interest to researchers and clinicians alike; however, until recently very little published data were available to support its use. This article summarizes the available scientific data of pharmacology from human and animal studies on the major cannabinoids which have been of interest in the treatment of epilepsy, including ∆9-tetrahydrocannabinol (∆9-THC), cannabidiol (CBD), ∆9-tetrahydrocannabivarin (∆9-THCV), cannabidivarin (CBDV), and ∆9-tetrahydrocannabinolic acid (Δ9-THCA). It has long been known that ∆9-THC has partial agonist activity at the endocannabinoid receptors CB1 and CB2, though it also binds to other targets which may modulate neuronal excitability and neuroinflammation. The actions of Δ9-THCV and Δ9-THCA are less well understood. In contrast to ∆9-THC, CBD has low affinity for CB1 and CB2 receptors and other targets have been investigated to explain its anticonvulsant properties including TRPV1, voltage gated potassium and sodium channels, and GPR55, among others. We describe the absorption, distribution, metabolism, and excretion of each of the above mentioned compounds. Cannabinoids as a whole are very lipophilic, resulting in decreased bioavailability, which presents challenges in optimal drug delivery. Finally, we discuss the limited drug-drug interaction data available on THC and CBD. As cannabinoids and cannabis-based products are studied for efficacy as anticonvulsants, more investigation is needed regarding the specific targets of action, optimal drug delivery, and potential drug-drug interactions. This article is part of a Special Issue titled Cannabinoids and Epilepsy.
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191
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Rosenberg EC, Patra PH, Whalley BJ. Therapeutic effects of cannabinoids in animal models of seizures, epilepsy, epileptogenesis, and epilepsy-related neuroprotection. Epilepsy Behav 2017; 70:319-327. [PMID: 28190698 PMCID: PMC5651410 DOI: 10.1016/j.yebeh.2016.11.006] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 11/03/2016] [Indexed: 12/21/2022]
Abstract
The isolation and identification of the discrete plant cannabinoids in marijuana revived interest in analyzing historical therapeutic claims made for cannabis in clinical case studies and anecdotes. In particular, sources as old as the 11th and 15th centuries claimed efficacy for crude marijuana extracts in the treatment of convulsive disorders, prompting a particularly active area of preclinical research into the therapeutic potential of plant cannabinoids in epilepsy. Since that time, a large body of literature has accumulated describing the effects of several of the >100 individual plant cannabinoids in preclinical models of seizures, epilepsy, epileptogenesis, and epilepsy-related neuroprotection. We surveyed the literature for relevant reports of such plant cannabinoid effects and critically reviewed their findings. We found that acute CB1R agonism in simple models of acute seizures in rodents typically produces anti-convulsant effects whereas CB1R antagonists exert converse effects in the same models. However, when the effects of such ligands are examined in more complex models of epilepsy, epileptogenesis and neuroprotection, a less simplistic narrative emerges. Here, the complex interactions between (i) brain regions involved in a given model, (ii) relative contributions of endocannabinoid signaling to modulation of synaptic transmission in such areas, (iii) multi-target effects, (iv) cannabinoid type 1 and type 2 receptor signaling interactions and, (v) timing, (vi) duration and (vii) localization of ligand administration suggest that there is both anti-epileptic therapeutic potential and a pro-epileptic risk in up- and down-regulation of endocannabinoid signaling in the central nervous system. Factors such receptor desensitization and specific pharmacology of ligands used (e.g. full vs partial agonists and neutral antagonists vs inverse agonists) also appear to play an important role in the effects reported. Furthermore, the effects of several plant cannabinoids, most notably cannabidiol (CBD) and cannabidavarin (CBDV), in models of seizures, epilepsy, epileptogenesis, and neuroprotection are less ambiguous, and consistent with reports of therapeutically beneficial effects of these compounds in clinical studies. However, continued paucity of firm information regarding the therapeutic molecular mechanism of CBD/CBDV highlights the continued need for research in this area in order to identify as yet under-exploited targets for drug development and raise our understanding of treatment-resistant epilepsies. The recent reporting of positive results for cannabidiol treatment in two Phase III clinical trials in treatment-resistant epilepsies provides pivotal evidence of clinical efficacy for one plant cannabinoid in epilepsy. Moreover, risks and/or benefits associated with the use of unlicensed Δ9-THC containing marijuana extracts in pediatric epilepsies remain poorly understood. Therefore, in light of these paradigm-changing clinical events, the present review's findings aim to drive future drug development for newly-identified targets and indications, identify important limitations of animal models in the investigation of plant cannabinoid effects in the epilepsies, and focuses future research in this area on specific, unanswered questions regarding the complexities of endocannabinoid signaling in epilepsy. This article is part of a Special Issue titled Cannabinoids and Epilepsy.
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Affiliation(s)
- Evan C. Rosenberg
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Langone Medical Center, New York, NY 10016, USA
| | - Pabitra H. Patra
- Department of Pharmacy, School of Chemistry, Food & Nutritional Sciences and Pharmacy, University of Reading, Whiteknights, Reading, Berkshire RG6 6AP, UK
| | - Benjamin J. Whalley
- Department of Pharmacy, School of Chemistry, Food & Nutritional Sciences and Pharmacy, University of Reading, Whiteknights, Reading, Berkshire RG6 6AP, UK,Corresponding author: (B.J. Whalley)
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192
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Patel S, Hill MN, Cheer JF, Wotjak CT, Holmes A. The endocannabinoid system as a target for novel anxiolytic drugs. Neurosci Biobehav Rev 2017; 76:56-66. [PMID: 28434588 PMCID: PMC5407316 DOI: 10.1016/j.neubiorev.2016.12.033] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 11/22/2016] [Accepted: 12/16/2016] [Indexed: 12/01/2022]
Abstract
The endocannabinoid (eCB) system has attracted attention for its role in various behavioral and brain functions, and as a therapeutic target in neuropsychiatric disease states, including anxiety disorders and other conditions resulting from dysfunctional responses to stress. In this mini-review, we highlight components of the eCB system that offer potential 'druggable' targets for new anxiolytic medications, emphasizing some of the less well-discussed options. We discuss how selectively amplifying eCBs recruitment by interfering with eCB-degradation, via fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), has been linked to reductions in anxiety-like behaviors in rodents and variation in human anxiety symptoms. We also discuss a non-canonical route to regulate eCB degradation that involves interfering with cyclooxygenase-2 (COX-2). Next, we discuss approaches to targeting eCB receptor-signaling in ways that do not involve the cannabinoid receptor subtype 1 (CB1R); by targeting the CB2R subtype and the transient receptor potential vanilloid type 1 (TRPV1). Finally, we review evidence that cannabidiol (CBD), while representing a less specific pharmacological approach, may be another way to modulate eCBs and interacting neurotransmitter systems to alleviate anxiety. Taken together, these various approaches provide a range of plausible paths to developing novel compounds that could prove useful for treating trauma-related and anxiety disorders.
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Affiliation(s)
- Sachin Patel
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, USA; Vanderbilt Kennedy Center for Human Development, Vanderbilt University Medical Center, Nashville, USA
| | - Mathew N Hill
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Mathison Centre for Mental Health Research and Education, University of Calgary, Calgary, AB, Canada; Departments of Cell Biology and Anatomy and Psychiatry, University of Calgary, Calgary, AB, Canada
| | - Joseph F Cheer
- Department of Anatomy and Neurobiology and Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Carsten T Wotjak
- Max Planck Institute of Psychiatry, Department of Stress Neurobiology & Neurogenetics, Munich, Germany
| | - Andrew Holmes
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA.
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193
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Robertson JM, Achua JK, Smith JP, Prince MA, Staton CD, Ronan PJ, Summers TR, Summers CH. Anxious behavior induces elevated hippocampal Cb 2 receptor gene expression. Neuroscience 2017; 352:273-284. [PMID: 28392296 DOI: 10.1016/j.neuroscience.2017.03.061] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 03/23/2017] [Accepted: 03/29/2017] [Indexed: 11/25/2022]
Abstract
Anxiety is differentially expressed across a continuum of stressful/fearful intensity, influenced by endocannabinoid systems and receptors. The hippocampus plays important roles in the regulation of affective behavior, emotion, and anxiety, as well as memory. Location of Cb1/Cb2 receptor action could be important in determining emotional valence, because while the dorsal hippocampus is involved in spatial memory and cognition, the ventral hippocampus has projections to the PFC, BNST, amygdala, and HPA axis, and is important for emotional responses to stress. During repeated social defeat in a Stress-Alternatives Model arena (SAM; an oval open field with escape portals only large enough for smaller mice), smaller C57BL6/N mice are subject to fear conditioning (tone=CS), and attacked by novel larger aggressive CD1 mice (US) over four daily (5min) trials. Each SAM trial presents an opportunity for escape or submission, with stable behavioral responses established by the second day of interaction. Additional groups had access to a running wheel. Social aggression plus fear conditioning stimulates enhanced Cb2 receptor gene expression in the dorsal CA1, dorsal and ventral dentate gyrus subregions in animals displaying a submissive behavioral phenotype. Escape behavior is associated with reduced Cb2 expression in the dorsal CA1 region, with freezing and escape latency correlated with mRNA levels. Escaping and submitting animals with access to running wheels had increased Cb2 mRNA in dorsal DG/CA1. These results suggest that the Cb2 receptor system is rapidly induced during anxiogenic social interactions plus fear conditioning or exercise; with responses potentially adaptive for coping mechanisms.
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Affiliation(s)
- James M Robertson
- Department of Biology, University of South Dakota, Vermillion, SD 57069, USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA
| | - Justin K Achua
- Department of Biology, University of South Dakota, Vermillion, SD 57069, USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD 57105, USA; Avera McKennan Hospital & University Health Center, Sioux Falls, SD 57105, USA
| | - Justin P Smith
- Department of Biology, University of South Dakota, Vermillion, SD 57069, USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD 57105, USA; Institute of Possibility, 322 E. 8th Street, Suite 302, Sioux Falls, SD 57103, USA; Sanford Health, 2301 E. 60th St. N., Sioux Falls, SD 57104, USA
| | - Melissa A Prince
- Department of Biology, University of South Dakota, Vermillion, SD 57069, USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD 57105, USA
| | - Clarissa D Staton
- Department of Biology, University of South Dakota, Vermillion, SD 57069, USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD 57105, USA
| | - Patrick J Ronan
- Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD 57105, USA; Department of Psychiatry, University of South Dakota School of Medicine Vermillion, SD, USA; Laboratory for Clinical and Translational Research in Psychiatry, Department of Veterans Affairs Medical Center, Denver, CO 80220, USA
| | - Tangi R Summers
- Department of Biology, University of South Dakota, Vermillion, SD 57069, USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD 57105, USA
| | - Cliff H Summers
- Department of Biology, University of South Dakota, Vermillion, SD 57069, USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD 57105, USA.
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194
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Lupica CR, Hu Y, Devinsky O, Hoffman AF. Cannabinoids as hippocampal network administrators. Neuropharmacology 2017; 124:25-37. [PMID: 28392266 DOI: 10.1016/j.neuropharm.2017.04.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 04/03/2017] [Accepted: 04/04/2017] [Indexed: 12/30/2022]
Abstract
Extensive pioneering studies performed in the hippocampus have greatly contributed to our knowledge of an endogenous cannabinoid system comprised of the molecular machinery necessary to process endocannabinoid lipid messengers and their associated cannabinoid receptors. Moreover, a foundation of knowledge regarding the function of hippocampal circuits, and its role in supporting synaptic plasticity has facilitated our understanding of the roles cannabinoids play in the diverse behaviors in which the hippocampus participates, in both normal and pathological states. In this review, we present an historical overview of research pertaining to the hippocampal cannabinoid system to provide context in which to understand the participation of the hippocampus in cognition, behavior, and epilepsy. We also examine potential roles for the hippocampal formation in mediating dysfunctional behavior, and assert that these phenomena reflect disordered physiological activity within the hippocampus and its interactions with other brain regions after exposure to synthetic cannabinoids, and the phytocannabinoids found in marijuana, such as Δ9-THC and cannabidiol. In this regard, we examine contemporary hypotheses concerning the hippocampal endocannabinoid system's participation in psychotic disorders, schizophrenia, and epilepsy, and examine cannabinoid-sensitive cellular mechanisms contributing to coherent network oscillations as potential contributors to these disorders. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".
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Affiliation(s)
- Carl R Lupica
- U.S. Department of Health and Human Services, National Institutes of Health, National Institute on Drug Abuse Intramural Research Program, Electrophysiology Research Section, Baltimore, MD, USA.
| | - Yuhan Hu
- School of Chemistry, Food and Nutritional Sciences and Pharmacy, University of Reading, Reading, UK
| | | | - Alexander F Hoffman
- U.S. Department of Health and Human Services, National Institutes of Health, National Institute on Drug Abuse Intramural Research Program, Electrophysiology Research Section, Baltimore, MD, USA
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195
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Shiri M, Komaki A, Oryan S, Taheri M, Komaki H, Etaee F. Effects of cannabinoid and vanilloid receptor agonists and their interaction on learning and memory in rats. Can J Physiol Pharmacol 2017; 95:382-387. [DOI: 10.1139/cjpp-2016-0274] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Despite previous findings on the effects of cannabinoid and vanilloid systems on learning and memory, the effects of the combined stimulation of these 2 systems on learning and memory have not been studied. Therefore, in this study, we tested the interactive effects of cannabinoid and vanilloid systems on learning and memory in rats by using passive avoidance learning (PAL) tests. Forty male Wistar rats were divided into the following 4 groups: (1) control (DMSO+saline), (2) WIN55,212–2, (3) capsaicin, and (4) WIN55,212–2 + capsaicin. On test day, capsaicin, a vanilloid receptor type 1 (TRPV1) agonist, or WIN55,212–2, a cannabinoid receptor (CB1/CB2) agonist, or both substances were injected intraperitoneally. Compared to the control group, the group treated with capsaicin (TRPV1 agonist) had better scores in the PAL acquisition and retention test, whereas treatment with WIN55,212–2 (CB1/CB2 agonist) decreased the test scores. Capsaicin partly reduced the effects of WIN55,212–2 on PAL and memory. We conclude that the acute administration of a TRPV1 agonist improves the rats’ cognitive performance in PAL tasks and that a vanilloid-related mechanism may underlie the agonistic effect of WIN55,212–2 on learning and memory.
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Affiliation(s)
- Mariam Shiri
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Alireza Komaki
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Shahrbanoo Oryan
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Masoumeh Taheri
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Hamidreza Komaki
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Farshid Etaee
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
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196
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Gantz SC, Bean BP. Cell-Autonomous Excitation of Midbrain Dopamine Neurons by Endocannabinoid-Dependent Lipid Signaling. Neuron 2017; 93:1375-1387.e2. [PMID: 28262417 DOI: 10.1016/j.neuron.2017.02.025] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 11/28/2016] [Accepted: 02/09/2017] [Indexed: 01/13/2023]
Abstract
The major endocannabinoid in the mammalian brain is the bioactive lipid 2-arachidonoylglycerol (2-AG). The best-known effects of 2-AG are mediated by G-protein-coupled cannabinoid receptors. In principle, 2-AG could modify neuronal excitability by acting directly on ion channels, but such mechanisms are poorly understood. Using a preparation of dissociated mouse midbrain dopamine neurons to isolate effects on intrinsic excitability, we found that 100 nM 2-AG accelerated pacemaking and steepened the frequency-current relationship for burst-like firing. In voltage-clamp experiments, 2-AG reduced A-type potassium current (IA) through a cannabinoid receptor-independent mechanism mimicked by arachidonic acid, which has no activity on cannabinoid receptors. Activation of orexin, neurotensin, and metabotropic glutamate Gq/11-linked receptors mimicked the effects of exogenous 2-AG and their actions were prevented by inhibiting the 2-AG-synthesizing enzyme diacylglycerol lipase α. The results show that 2-AG and related lipid signaling molecules can directly tune neuronal excitability in a cell-autonomous manner by modulating IA.
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Affiliation(s)
- Stephanie C Gantz
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
| | - Bruce P Bean
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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197
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Chen DJ, Gao M, Gao FF, Su QX, Wu J. Brain cannabinoid receptor 2: expression, function and modulation. Acta Pharmacol Sin 2017; 38:312-316. [PMID: 28065934 PMCID: PMC5342669 DOI: 10.1038/aps.2016.149] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 10/18/2016] [Indexed: 02/06/2023] Open
Abstract
Cannabis sativa (marijuana) is a fibrous flowering plant that produces an abundant variety of molecules, some with psychoactive effects. At least 4% of the world's adult population uses cannabis annually, making it one of the most frequently used illicit drugs in the world. The psychoactive effects of cannabis are mediated primarily through cannabinoid receptor (CBR) subtypes. The prevailing view is that CB1Rs are mainly expressed in the central neurons, whereas CB2Rs are predominantly expressed in peripheral immune cells. However, this traditional view has been challenged by emerging strong evidence that shows CB2Rs are moderately expressed and function in specific brain areas. New evidence has demonstrated that brain CB2Rs modulate animal drug-seeking behaviors, suggesting that these receptors may exist in brain regions that regulate drug addiction. Recently, we further confirmed that functional CB2Rs are expressed in mouse ventral tegmental area (VTA) dopamine (DA) neurons and that the activation of VTA CB2Rs reduces neuronal excitability and cocaine-seeking behavior. In addition, CB2R-mediated modulation of hippocampal CA3 neuronal excitability and network synchronization has been reported. Here, we briefly summarize recent lines of evidence showing how CB2Rs modulate function and pathophysiology in the CNS.
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Affiliation(s)
- De-jie Chen
- Department of Neurology, Yunfu People's Hospital, Yunfu 527300, China
- Department of Neurobiology, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, AZ 85013–4409, USA
| | - Ming Gao
- Department of Neurobiology, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, AZ 85013–4409, USA
| | - Fen-fei Gao
- Department of Neurobiology, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, AZ 85013–4409, USA
- Department of Pharmacology, Shantou University Medical College, Shantou 515041, China
| | - Quan-xi Su
- Department of Neurology, Yunfu People's Hospital, Yunfu 527300, China
| | - Jie Wu
- Department of Neurology, Yunfu People's Hospital, Yunfu 527300, China
- Department of Neurobiology, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, AZ 85013–4409, USA
- Department of Pharmacology, Shantou University Medical College, Shantou 515041, China
- E-mail
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198
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Abstract
An agonist that acts through a single receptor can activate numerous signaling pathways. Recent studies have suggested that different ligands can differentially activate these pathways by stabilizing a limited range of receptor conformations, which in turn preferentially drive different downstream signaling cascades. This concept, termed "biased signaling" represents an exciting therapeutic opportunity to target specific pathways that elicit only desired effects, while avoiding undesired effects mediated by different signaling cascades. The cannabinoid receptors CB1 and CB2 each activate multiple pathways, and evidence is emerging for bias within these pathways. This review will summarize the current evidence for biased signaling through cannabinoid receptor subtypes CB1 and CB2.
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Affiliation(s)
- Mikkel Søes Ibsen
- Department of Pharmacology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Mark Connor
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, 2 Technology Place, Macquarie University, New South Wales, Australia
| | - Michelle Glass
- Department of Pharmacology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
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199
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Salort G, Álvaro-Bartolomé M, García-Sevilla JA. Regulation of cannabinoid CB 2 receptor constitutive activity in vivo: repeated treatments with inverse agonists reverse the acute activation of JNK and associated apoptotic signaling in mouse brain. Psychopharmacology (Berl) 2017; 234:925-941. [PMID: 28127623 DOI: 10.1007/s00213-017-4537-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 01/07/2017] [Indexed: 01/29/2023]
Abstract
RATIONALE CB2 receptors express constitutive activity and inverse agonists regulate receptor basal activity, which might be involved in death mechanisms. This study assessed the effects of a selective CB2 agonist (JWH133) and different CB2 inverse agonists (AM630, JTE907, raloxifene) on death pathways in brain. OBJECTIVES The acute (JWH13) and the acute/chronic effects (AM630, JTE907, raloxifene) of CB2 ligands regulating pro-apoptotic c-Jun NH2-terminal kinase (p-JNK/JNK ratio) and associated signaling of extrinsic (Fas receptor, Fas-Associated death domain protein, FADD) and intrinsic (Bax, cytochrome c) death pathways (nuclear poly (ADP-ribose) polymerase PARP) were investigated in mouse brain. METHODS Mice were treated with CB2 drugs and target protein contents were assessed by western blot analysis. RESULTS JWH133 reduced cortical JNK (-27-45%) whereas AM630 acutely increased JNK in cortex (+61-148%), cerebellum (+34-40%), and striatum (+33-42%). JTE907 and raloxifene also increased cortical JNK (+31%-57%). Acute AM630, but not JWH133, increased cortical FADD, Bax, cytochrome c, and PARP cleavage. Repeated treatments with the three CB2 inverse agonists were associated with a reversal of the acute effects resulting in decreases in cortical JNK (AM630: -36%; JTE907: -25%; raloxifene: -11%). Chronic treatments also induced a reversal with down-regulation (AM630) or only tolerance (JTE907 and raloxifene) on other apoptotic markers (FADD, Bax, cytochrome c, PARP). CONCLUSIONS AM630 and JTE907 are CB2 protean ligands. Thus, chronic inverse agonists abolished CB2 constitutive activity and then the ligands behaved as agonists reducing (like JWH133) JNK activity. Acute and chronic treatments with CB2 inverse agonists regulate in opposite directions brain death markers.
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Affiliation(s)
- Glòria Salort
- Laboratori de Neurofarmacologia, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS/IdisPa), Universitat de les Illes Balears, Cra. Valldemossa km 7.5, E-07122, Palma de Mallorca, Spain.,Redes Temáticas de Investigación Cooperativa en Salud-Red de Trastornos Adictivos (RETICS-RTA), ISCIII, Madrid, Spain
| | - María Álvaro-Bartolomé
- Laboratori de Neurofarmacologia, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS/IdisPa), Universitat de les Illes Balears, Cra. Valldemossa km 7.5, E-07122, Palma de Mallorca, Spain.,Redes Temáticas de Investigación Cooperativa en Salud-Red de Trastornos Adictivos (RETICS-RTA), ISCIII, Madrid, Spain
| | - Jesús A García-Sevilla
- Laboratori de Neurofarmacologia, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS/IdisPa), Universitat de les Illes Balears, Cra. Valldemossa km 7.5, E-07122, Palma de Mallorca, Spain. .,Redes Temáticas de Investigación Cooperativa en Salud-Red de Trastornos Adictivos (RETICS-RTA), ISCIII, Madrid, Spain.
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200
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Li W, Zhang CL, Qiu ZG. Differential expression of endocannabinoid system-related genes in the dorsal hippocampus following expression and reinstatement of morphine conditioned place preference in mice. Neurosci Lett 2017; 643:38-44. [PMID: 28192193 DOI: 10.1016/j.neulet.2017.02.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 02/07/2017] [Accepted: 02/08/2017] [Indexed: 11/15/2022]
Abstract
The endocannabinoid signaling plays a critical role in mediating rewarding effects to morphine. The relative stability for the expression and reinstatement of morphine conditioned place preference (CPP) suggests the involvement of differential neuroadaptations in learned associations between environmental cues and morphine. Changes in gene expression in hippocampus through the endogenous cannabinoid system (eCB) may accompany and mediate the development of such neuroadaptations to repeated morphine stimulation. To test this possibility, we systematically compared the expression of eCB-related genes in the dorsal hippocampus following the expression, extinction, and reinstatement of morphine CPP using quantitative RT-PCR analyses. We found that expression of morphine CPP was associated with significant increases in mRNA expression for the primary clearance routes for anandamide (AEA) and 2-AG (fatty acid amide hydrolase [FAAH] and monoacylglycerol lipase [MAGL], respectively), but with reductions in cannabinoid 1 receptors (CB1R) and CB2R in dorsal hippocampus following the expression of CPP. However, our results indicated that decreased in MAGL and increased CB1R mRNA levels were accompanied with morphine CPP reinstatement. No significant changes in mRNA expression for enzymes involved in AEA and 2-AG biosynthesis (N-acylphosphatidylethanolamine phospholipase D [NAPEPLD] and diacylglycerol lipase-α/β [DAGLα/β], respectively) were found in all conditions. These results suggest that differential regulation of the synthesis and/or degradation of the eCB system contribute to the expression and reinstatement of morphine CPP.
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Affiliation(s)
- Wei Li
- Department of Anesthesia, The Second Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Cong-Li Zhang
- Department of Anesthesiology, Xi'an Xidian Group Hospital, Xi'an, China
| | - Zheng-Guo Qiu
- Department of Anesthesiology, Xi'an Xidian Group Hospital, Xi'an, China.
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