“Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease of the motor neuron system with limited therapeutic options. While an increasing number of ALS patients can be linked to a small number of autosomal-dominantly inherited cases, most cases are termed sporadic. Both forms are clinically and histopathologically indistinguishable, raising the prospect that they share key pathogenic steps, including potential therapeutic intervention points. The endocannabinoid system is emerging as a versatile, druggable therapeutic target in the CNS and its dysregulation is an early hallmark of neurodegeneration. Whether this is a defense mechanism or part of the pathogenesis remains to be determined. The neuroprotective and anti-inflammatory endocannabinoid 2-arachidonoylglycerol (2-AG), which is degraded by monoacylglycerol lipase (MAGL), accumulates in the spinal cords of transgenic models of ALS. We tested the hypothesis that this 2-AG increase is a protective response in the low-copy SOD1G93A mouse model of ALS. We show that oral application of the MAGL inhibitor KML29 delays disease onset, progression and survival. Furthermore, we could demonstrate that KML29 reduced proinflammatory cytokines and increased brain-derived neurotrophic factor (BDNF) expression levels in the spinal cord, the major site of neurodegeneration in ALS. Moreover, treatment of primary mouse neurons and primary mousecroglia with 2-AG confirmed the neuroprotective and anti-inflammatory action by increasing BDNF and arginase-1 and decreasing proinflammatory cytokines in vitro. In summary, we show that elevating 2-AG levels by MAGL inhibition is a therapeutic target in ALS and demonstrate that the endocannabinoid defense mechanisms can be exploited therapeutically in neurodegenerative diseases.” https://www.ncbi.nlm.nih.gov/pubmed/28373073]]>
Category Archives: Endocannabinoid System
Binding Site Characterization of AM1336, a Novel Covalent Inverse Agonist at Human Cannabinoid 2 Receptor, Using Mass Spectrometric Analysis.
“Cannabinoid 2 receptor (CB2R), a Class A G-protein coupled receptor (GPCR), is a promising drug target in a wide array of pathological conditions. Rational drug design has been hindered due to our poor understanding of the structural features involved in ligand binding. Binding of a high-affinity biarylpyrazole inverse agonist AM1336 to a library of the human CB2 receptor (hCB2R) cysteine-substituted mutants provided indirect evidence that two cysteines in transmembrane helix-7 (H7) were critical for the covalent attachment. Here, we used proteomics analysis of the hCB2R with bound AM1336 to directly identify peptides with covalently attached ligand and applied in-silico modeling for visualization of the ligand-receptor interactions. The hCB2R, with affinity tags (FlaghCB2His6), was produced in a baculovirus-insect cell expression system and purified as a functional receptor using immunoaffinity chromatography. Using mass spectrometry-based bottom-up proteomic analysis of the hCB2R-AM1336 we identified a peptide with AM1336 attached to the cysteine C284(7.38) in H7. The hCB2R homology model in lipid bilayer accommodated covalent attachment of AM1336 to C284(7.38), supporting both biochemical and mass spectrometric data. This work consolidates proteomics data and in-silico modeling, and integrates with our ligand-assisted protein structure (LAPS) experimental paradigm to assist in structure-based design of cannabinoid antagonist/inverse agonists.”
https://www.ncbi.nlm.nih.gov/pubmed/28374590
(-)-β-Caryophyllene, a CB2 Receptor-Selective Phytocannabinoid, Suppresses Motor Paralysis and Neuroinflammation in a Murine Model of Multiple Sclerosis.
“(-)-β-caryophyllene (BCP), a cannabinoid receptor type 2 (CB2)-selective phytocannabinoid, has already been shown in precedent literature to exhibit both anti-inflammatory and analgesic effects in mouse models of inflammatory and neuropathic pain. Herein, we endeavored to investigate the therapeutic potential of BCP on experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis (MS). Furthermore, we sought to demonstrate some of the mechanisms that underlie the modulation BCP exerts on autoimmune activated T cells, the pro-inflammatory scenery of the central nervous system (CNS), and demyelination. Our findings demonstrate that BCP significantly ameliorates both the clinical and pathological parameters of EAE. In addition, data hereby presented indicates that mechanisms underlying BCP immunomodulatory effect seems to be linked to its ability to inhibit microglial cells, CD4+ and CD8+ T lymphocytes, as well as protein expression of pro-inflammatory cytokines. Furthermore, it diminished axonal demyelination and modulated Th1/Treg immune balance through the activation of CB2 receptor. Altogether, our study represents significant implications for clinical research and strongly supports the effectiveness of BCP as a novel molecule to target in the development of effective therapeutic agents for MS.” https://www.ncbi.nlm.nih.gov/pubmed/28368293 “β-caryophyllene (BCP) is a common constitute of the essential oils of numerous spice, food plants and major component in Cannabis.” http://www.ncbi.nlm.nih.gov/pubmed/23138934]]>
Post-sensitization treatment with rimonabant blocks the expression of cocaine-induced behavioral sensitization and c-Fos protein in mice.
“CB1 receptor antagonists have been shown to prevent acute and long-term behavioral effects of cocaine. Here we evaluate the effectiveness of the CB1 receptor antagonist rimonabant to modify sensitized responses to cocaine. Our findings add to the evidence that drugs targeting CB1 receptors are good candidates for the treatment of cocaine abuse and provide further insights into the mechanisms underlying endocannabinoid signaling within the brain reward system in the context of cocaine abuse.” https://www.ncbi.nlm.nih.gov/pubmed/28366798]]>
[Role of cannabinoid receptor 1-mediated synaptic plasticity in neuropathic pain and associated depression].
“Neuropathic pain is a class of pain caused by an injury or diseases of the somatosensory system and characterized by spontaneous pain, allodynia, and hyperalgesia. It is well established that central sensitization is one of the key mechanisms underlying the development and maintenance of neuropathic pain. Cannabinoid receptor 1 (CB1R) of endocannabinoid system modulates synaptic transmission, regulates synaptic plasticity, inhibits central sensitization, and thus attenuates neuropathic pain. Recent studies have shown that activation of CB1R also involves in the relief of neuropathic pain-induced depression.” https://www.ncbi.nlm.nih.gov/pubmed/28364110
“Treatment of inflammatory pain with opioids is accompanied by unpleasant and, at times, life-threatening side effects.
Cannabis produces antinociception as well as psychotropic effects. It was hypothesized that peripheral cannabinoid receptors outside the central nervous system could be selectively activated for relief of pain.
This study was undertaken to measure the antinociceptive effect of type 1 cannabinoid receptor (CB1r) agonist arachidonylcyclopropylamide (ACPA) in a rat model of inflammatory pain after intrawound administration and the effects were compared with lignocaine.
Lignocaine attenuated evoked pain behaviour whereas ACPA decreased guarding score. This difference was likely due to blockade of sodium ion channels and the activation of peripheral CB1r, respectively. Central side effects were absent after ACPA treatment. Further studies need to be done to assess the effect of ACPA treatment in clinical conditions.”