Cannabinoid CB1 Research Articles

Canine immune cells express high levels of CB1 and CB2 cannabinoid receptors and cannabinoid-mediated alteration of canine cytokine production is vehicle-dependent

With the increased popularity and societal acceptance of marijuana and cannabidiol (CBD) use in humans, there is an interest in using cannabinoids in veterinary medicine. There have been a few placebo-controlled clinical trials in dogs suggesting that cannabis-containing extracts are beneficial for dogs with inflammatory diseases such as osteoarthritis, and there is growing interest in their immunosuppressive potential for the treatment of immune-mediated diseases. Since cannabinoids exhibit anti-inflammatory and immunosuppressive effects in many species, the purpose of these studies was to examine whether the plant-derived cannabinoids, CBD and Δ9-tetrahydrocannabinol (THC), would also suppress immune function in canine peripheral blood mononuclear cells (PBMCs). Another goal was to characterize expression of the cannabinoid receptors, CB1 and CB2, in canine immune cells. We hypothesized that CBD and THC would suppress stimulated cytokine expression and that both cannabinoid receptors would be expressed in canine immune cells. Surprisingly, cannabinoid suppressive effects in canine PMBCs were quite modest, with the most robust effect occurring at early stimulation times and predominantly by THC. We further showed that cannabinoid-mediated suppression was dog- and vehicle-dependent with CBD and THC delivered in dimethyl sulfoxide (DMSO) producing more immune suppressive effects as compared to ethanol (ETOH). PCR, flow cytometry, and immunohistochemical staining demonstrated that both CB1 and CB2 are expressed in canine immune cells. Together these data show that canine immune cells are sensitive to suppression by cannabinoids, but more detailed studies are needed to further understand the mechanisms and broad effects of these compounds in the dog.

Complex Regional Pain Syndrome Type I: Evidence for the CB1 and CB2 Receptors Immunocontent and Beneficial Effect of Local Administration of Cannabidiol in Mice.

Introduction: Complex regional pain syndrome type I (CRPS-I) is a debilitating neuropathic painful condition associated with allodynia, hyperalgesia, sudomotor and/or vasomotor dysfunctions, turning investigation of its pathophysiology and new therapeutic strategies into an essential topic. We aim to investigate the impact of ischemia/reperfusion injury on the immunocontent of CB1 and CB2 cannabinoid receptor isoforms in the paws of mice submitted to a chronic postischemia pain (CPIP) model and the effects of local administration of cannabidiol (CBD) on mechanical hyperalgesia. Methods: Female Swiss mice, 30-35 g, were submitted to the CPIP model on the right hind paw. Skin and muscle samples were removed at different periods for western blot analysis. Results: No changes in the immunocontent of CB1 and CB2 receptors in paw muscle tissues after ischemia-reperfusion were observed. CBD promoted an antihyperalgesic effect in both phases. AM281 reversed the effect of CBD, whereas ruthenium red abolished the late phase. Conclusion: Our results point to the possible beneficial effects of local administration of CBD in modulating CRPS-I in humans. As possible targets for CBD antihyperalgesia in this model, the contribution of cannabinoid receptor CB1, in addition to TRPM8 is suggested.

Cannabinoid type-2 receptors modulate terpene induced anxiety-reduction in zebrafish

Terpenes are the most extensive and varied group of naturally occurring compounds mostly found in plants, including cannabis, and have an array of potential therapeutic benefits for pathological conditions. The endocannabinoid system can potently modulate anxiety in humans, rodents, and zebrafish. The ‘entourage effect’ suggests terpenes may target cannabinoid CB1 and CB2 receptors, among others, but this requires further investigation. In this study we first tested for anxiety-altering effects of the predominant ‘Super-Class’ terpenes, bisabolol (0.001%, 0.0015%, and 0.002%) and terpinolene (TPL; 0.01%, 0.05%, and 0.1%), in zebrafish with the open field test. Bisabolol did not have an effect on zebrafish behaviour or locomotion. However, TPL caused a significant increase in time spent in the inner zone and decrease in time spent in the outer zone of the arena indicating an anxiolytic (anxiety decreasing) effect. Next, we assessed whether CB1 and CB2 receptor antagonists, rimonabant and AM630 (6-Iodopravadoline) respectively, could eliminate or reduce the anxiolytic effects of TPL (0.1%) and β-caryophyllene (BCP; 4%), another super-class terpene previously shown to be anxiolytic in zebrafish. Rimonabant and AM630 were administered prior to terpene exposure and compared to controls and fish exposed to only the terpenes. AM630, but not rimonabant, eliminated the anxiolytic effects of both BCP and TPL. AM630 modulated locomotion on its own, which was potentiated by terpenes. These findings suggest the behavioural effects of TPL and BCP on zebrafish anxiety-like behaviour are mediated by a selective preference for CB2 receptor sites. Furthermore, the CB2 pathways mediating the anxiolytic response are likely different from those altering locomotion.

Cannabinoid CB2 receptor agonist reduces local and systemic inflammation associated with pneumonia-induced sepsis in mice

Sepsis is a severe condition secondary to dysregulated host response to infection leading to tissue damage and organ dysfunction. Cannabinoid CB2 receptor has modulatory effects on the immune response. Therefore, this study investigated the effects of a cannabinoid CB2 receptor agonist on the local and systemic inflammatory process associated with pneumonia-induced sepsis. Pneumonia-induced sepsis was induced in mice by intratracheal inoculation of Klebsiella pneumoniae. Tissue and bronchoalveolar lavage (BAL) were collected 6, 24, or 48 h after surgery. Mice were treated with CB2 agonist (AM1241, 0.3 and 3 mg/kg, i.p.) and several parameters of inflammation were evaluated 24 h after sepsis induction. Polymorphonuclear cell migration to the infectious focus peaked 24 h after pneumonia-induced sepsis induction in male and female animals. Septic male mice presented a significant reduction of cannabinoid CB2 receptor density in the lung tissue after 24 h, which was not observed in females. CB2 expression in BAL macrophages was also reduced in septic animals. Treatment of septic mice with AM1241 reduced cell migration, local infection, myeloperoxidase activity, protein extravasation, and NOS-2 expression in the lungs. In addition, the treatment reduced plasma IL-1β, increased IL-10 and reduced the severity and mortality of septic animals. These results suggest that AM1241 promotes an interesting balance in the inflammatory response, maintaining lung function and preventing organ injury. Therefore, cannabinoid CB2 receptors are potential targets to control the excessive inflammatory process that occurs in severe conditions, and agonists of these receptors can be considered promising adjuvants in pneumonia-induced sepsis treatment.

Memory impairment was ameliorated by corticolimbic microinjections of arachidonylcyclopropylamide (ACPA) and miRNA-regulated lentiviral particles in a streptozotocin-induced Alzheimer's rat model

The present study aimed to investigate the effect of corticolimbic cannabinoid CB1 receptors activity on memory impairment in the intracerebroventricular (ICV)-streptozotocin (STZ) animal model of Alzheimer's like-disease. This study also assessed whether the corticolimbic overexpression of miRNA-137 or -let-7a could increase the endocannabinoids by inhibiting the monoglyceride lipase (MAGL) to ameliorate STZ response. The results showed that ICV microinjection of STZ (3 mg/kg/10 μl) impaired passive avoidance memory retrieval. The chronic microinjection of arachidonylcyclopropylamide (ACPA; 10 ng/0.5 μl), a selective cannabinoid CB1 receptor agonist, into the hippocampal CA1 region, the central amygdala (CeA) or the medial prefrontal cortex (mPFC) ameliorated the amnesic effect of ICV-STZ. Intra-CA1 or -CeA microinjection of ACPA alone did not affect memory retrieval, while its microinjection into the mPFC impaired memory formation. Based on bioinformatics analysis and verification of the MAGL gene, miRNA-137 and -let-7a were chosen to target the expression levels of MAGL in the corticolimbic regions. The chronic corticolimbic microinjection of lentiviral particles containing miRNA-137 or -let-7a ameliorated ICV-STZ-induced memory impairment. The high transfection efficiency was determined for each virus using comparing fluorescent and conventional vision. Corticolimbic overexpression of miRNA-137 or -let-7a decreased the MAGL gene expression that encodes the MAGL enzyme to increase the endocannabinoids. Thus, among the molecular mechanisms and signaling pathways involved in the pathophysiology of Alzheimer's disease (AD), it is worth mentioning the role of endocannabinoids in the corticolimbic regions. CB1 receptor agonists, miRNA-137 or -let-7a, may be potential therapeutic targets against cognitive decline in AD.

Cannabis constituents for chronic neuropathic pain; reconciling the clinical and animal evidence.

Chronic neuropathic pain is a debilitating pain syndrome caused by damage to the nervous system that is poorly served by current medications. Given these problems, clinical studies have pursued extracts of the plant Cannabis sativa as alternative treatments for this condition. The vast majority of these studies have examined cannabinoids which contain the psychoactive constituent delta-9-tetrahydrocannabinol (THC). While there have been some positive findings, meta-analyses of this clinical work indicates that this effectiveness is limited and hampered by side-effects. This review focuses on how recent preclinical studies have predicted the clinical limitations of THC-containing cannabis extracts, and importantly, point to how they might be improved. This work highlights the importance of targeting channels and receptors other than cannabinoid CB1 receptors which mediate many of the side-effects of cannabis.

Antiangiogenic Action of JZL184 on Endothelial Cells via Inhibition of VEGF Expression in Hypoxic Lung Cancer Cells.

JZL184, an inhibitor of monoacylglycerol lipase (MAGL) and thus of the degradation of the endocannabinoid 2-arachidonoylglycerol (2-AG), mediates various anticancer effects in preclinical studies. However, studies on the effect of this or other MAGL inhibitors under hypoxia, an important factor in tumor biology and response to cancer therapy, have not yet been performed in cancer cells. In the present study, the impact of the conditioned media (CM) of A549 and H358 lung cancer cells incubated with JZL184 under hypoxic conditions on the angiogenic properties of human umbilical vein endothelial cells (HUVECs) was investigated. Treatment of HUVECs with CM derived from cancer cells cultured for 48 h under hypoxic conditions was associated with a substantial increase in migration and tube formation compared with unconditioned medium, which was inhibited when cancer cells were incubated with JZL184. In this process, JZL184 led to a significant increase in 2-AG levels in both cell lines. Analysis of a panel of proangiogenic factors revealed inhibition of hypoxia-induced vascular endothelial growth factor (VEGF) expression by JZL184. Antiangiogenic and VEGF-lowering effects were also demonstrated for the MAGL inhibitor MJN110. Receptor antagonist experiments suggest partial involvement of the cannabinoid receptors CB1 and CB2 in the antiangiogenic and VEGF-lowering effects induced by JZL184. The functional importance of VEGF for angiogenesis in the selected system is supported by observations showing inhibition of VEGF receptor 2 (VEGFR2) phosphorylation in HUVECs by CM from hypoxic cancer cells treated with JZL184 or when hypoxic cancer cell-derived CM was spiked with a neutralizing VEGF antibody. On the other hand, JZL184 did not exert a direct effect on VEGFR2 activation induced by recombinant VEGF, so there seems to be no downstream effect on already released VEGF. In conclusion, these results reveal a novel mechanism of antiangiogenic action of JZL184 under conditions of hypoxic tumor-endothelial communication.

Basolateral Amygdala Cannabinoid CB1 Receptor Controls Formation and Elimination of Social Fear Memory.

Patients with post-traumatic stress disorder (PTSD) usually manifest persistence of the traumatic memory for a long time after the event, also known as resistance to extinction learning. Numerous studies have shown that the endocannabinoid system, specifically the cannabinoid type-1 receptor (CB1R), plays an important role in traumatic memory. However, the effect of basolateral amygdala (BLA) CB1R in social fear memory formation and elimination is still unclear. Here, we built a mouse model of social avoidance induced by acute social defeat stress to investigate the role of BLA CB1R in social fear memory formation and anxiety- and depression-like behavior. Anterograde knockout of CB1R in BLA neurons facilitates social fear memory formation and manifests an anxiolytic effect but does not influence sociability and social novelty. Retrograde knockout of CB1R in BLA promotes social fear memory formation and shows an anxiogenic effect but does not affect sociability and social novelty. Moreover, intracerebral injection of the CB1R antagonist AM251 in BLA during the memory reconsolidation time window eliminates social fear memory. Our findings suggest the CB1R of BLA can be used as a novel molecular target in social fear memory formation and elimination and potential PTSD therapy with memory retrieval and AM251.

Discovery and Characterization of Novel CNS-Penetrant GPR55 Agonists.

From our NETSseq-derived human brain transcriptomics data, we identified GPR55 as a potential molecular target for the treatment of motor symptoms in patients with Parkinson's disease. From a high-throughput screen, we identified and optimized agonists with nanomolar potency against both human and rat GPR55. We discovered compounds with either strong or limited β-arrestin signaling and receptor desensitization, indicating biased signaling. A compound that showed minimal GPR55 desensitization demonstrated a reduction in firing frequency of medium spiny neurons cultured from rat striatum but did not reverse motor deficits in a rat hypolocomotion model. Further profiling of several desensitizing and non-desensitizing lead compounds showed that they are selective over related cannabinoid receptors CB1 and CB2 and that unbound brain concentrations well above the respective GPR55 EC50 can be readily achieved following oral administration. The novel brain-penetrant GPR55 agonists disclosed can be used to probe the role of this receptor in the brain.

Revealing the biological mechanism of acupuncture in alleviating excessive inflammatory responses and organ damage in sepsis: a systematic review.

Sepsis is a systemic inflammation caused by a maladjusted host response to infection. In severe cases, it can cause multiple organ dysfunction syndrome (MODS) and even endanger life. Acupuncture is widely accepted and applied in the treatment of sepsis, and breakthroughs have been made regarding its mechanism of action in recent years. In this review, we systematically discuss the current clinical applications of acupuncture in the treatment of sepsis and focus on the mechanisms of acupuncture in animal models of systemic inflammation. In clinical research, acupuncture can not only effectively inhibit excessive inflammatory reactions but also improve the immunosuppressive state of patients with sepsis, thus maintaining immune homeostasis. Mechanistically, a change in the acupoint microenvironment is the initial response link for acupuncture to take effect, whereas PROKR2 neurons, high-threshold thin nerve fibres, cannabinoid CB2 receptor (CB2R) activation, and Ca2+ influx are the key material bases. The cholinergic anti-inflammatory pathway of the vagus nervous system, the adrenal dopamine anti-inflammatory pathway, and the sympathetic nervous system are key to the transmission of acupuncture information and the inhibition of systemic inflammation. In MODS, acupuncture protects against septic organ damage by inhibiting excessive inflammatory reactions, resisting oxidative stress, protecting mitochondrial function, and reducing apoptosis and tissue or organ damage.

Selective inhibition of cannabinoid CB1 receptor-evoked signalling by the interacting protein GAP43

Cannabinoids exert pleiotropic effects on the brain by engaging the cannabinoid CB1 receptor (CB1R), a presynaptic metabotropic receptor that regulates key neuronal functions in a highly context-dependent manner. We have previously shown that CB1R interacts with growth-associated protein of 43 kDa (GAP43) and that this interaction inhibits CB1R function on hippocampal excitatory synaptic transmission, thereby impairing the therapeutic effect of cannabinoids on epileptic seizures in vivo. However, the underlying molecular features of this interaction remain unexplored. Here, we conducted mechanistic experiments on HEK293T cells co-expressing CB1R and GAP43 and show that GAP43 modulates CB1R signalling in a strikingly selective manner. Specifically, GAP43 did not affect the archetypical agonist-evoked (i) CB1R/Gi/o protein-coupled signalling pathways, such as cAMP/PKA and ERK, or (ii) CB1R internalization and intracellular trafficking. In contrast, GAP43 blocked an alternative agonist-evoked CB1R-mediated activation of the cytoskeleton-associated ROCK signalling pathway, which relied on the GAP43-mediated impairment of CB1R/Gq/11 protein coupling. GAP43 also abrogated CB1R-mediated ROCK activation in mouse hippocampal neurons, and this process led in turn to a blockade of cannabinoid-evoked neurite collapse. An NMR-based characterization of the CB1R-GAP43 interaction supported that GAP43 binds directly and specifically through multiple amino acid stretches to the C-terminal domain of the receptor. Taken together, our findings unveil a CB1R-Gq/11-ROCK signalling axis that is selectively impaired by GAP43 and may ultimately control neurite outgrowth.

Towards the convergent therapeutic potential of GPCRs in autism spectrum disorders.

Autism spectrum disorders (ASD) are diagnosed in 1/100 children worldwide, based on two core symptoms, deficits in social interaction and communication and stereotyped behaviours. G protein-coupled receptors (GPCRs) are the largest family of cell-surface receptors that transduce extracellular signals to convergent intracellular signalling and downstream cellular responses that are commonly dysregulated in ASD. Despite hundreds of GPCRs being expressed in the brain, only 23 are genetically associated with ASD according to the Simons Foundation Autism Research Initiative (SFARI) gene database: oxytocin OTR, vasopressin V1A , V1B , metabotropic glutamate mGlu5 , mGlu7 , GABAB2 , dopamine D1 , D2 , D3 , serotoninergic 5-HT1B , β2 -adrenoceptor, cholinergic M3 , adenosine A2A , A3 , angiotensin AT2 , cannabinoid CB1 , chemokine CX3 CR1, orphan GPR37, GPR85 and olfactory OR1C1, OR2M4, OR2T10, OR52M1. Here, we review the therapeutic potential of these 23 GPCRs, 5-HT2A and 5-HT7 for ASD. For each GPCR, we discuss its genetic association, genetic and pharmacological manipulation in animal models, pharmacopeia for core symptoms of ASD and rank them based on these factors. Among these GPCRs, we highlight that D2 , 5-HT2A , CB1 , OTR and V1A are the most promising targets for ASD. We discuss that the dysregulation of GPCRs and their signalling is a convergent pathological mechanism of ASD. Their therapeutic potential has only begun as multiple GPCRs could mitigate ASD.

Influence of structural characteristics on the binding of synthetic cannabinoids from the JWH family to the CB1 receptor: A computational study

Synthetic cannabinoids, including some from the John W. Huffman (JWH) family, emerged on the drug scene around 2004 as “alternative marijuana,” despite being considerably more potent than marijuana. Like Δ9-tetrahydrocannabinol (THC), the principal psychoactive ingredient in marijuana, synthetic cannabinoids have also been found to interact with cannabinoid receptors CB1 and CB2, found in the brain, immune system, and peripheral organs. The JWH compounds and other synthetic cannabinoids have become important subjects of research in the forensic science community due to their drug-abuse potential, undetectability under routine drug screening, and unpredictable toxicity. In this study, an active-state CB1 receptor model was used to assess the receptor-ligand interactions between the CB1 receptor and ligands from the JWH synthetic cannabinoid family, as well as some newly designed JWH-like virtual compounds, labeled as MGCS compounds, using docking, binding free-energy calculations (ΔG), and molecular dynamics simulations (MDs). The calculated ΔG revealed that the carbonyl group between the naphthalene and the indole, characteristic of the JWH family, and the length of the N-linked alkyl chain were two important structural characteristics that influenced the predicted CB1 binding affinity, especially as increasing the length of the alkyl chain led to better predicted binding affinity. MDs and per-residue-breakdown results showed that the designed MGCS compounds with a pentyl chain attached to the naphthalene moiety and selected JWH compounds formed stable and strong hydrophobic interactions with the key residues Phe170, Phe174, Phe177, Phe200, Phe268, and Trp279 of the CB1 receptor. Comprehension of these critical interactions can help forensic chemists predict the structure of undiscovered families of synthetic cannabinoids.

Chemistry, Crystal Structure, and In Vitro Receptor Binding of Δ10-THC Isomers.

Introduction: The psychoactive properties of Δ10-THC isomers (trans- and cis-Δ10-THC) are poorly understood. To shed more light on the biological effects of these compounds, we studied in vitro receptor binding of Δ10-THC isomers at cannabinoid CB1 and CB2 receptors. Materials and Methods: We first optimized and simplified catalytic synthesis of trans- and cis-Δ10-THC to allow their safe and cheap large-scale synthesis. In our synthesis, BuLi was replaced with KOtBu, and DMSO/anisole or NEt3/heptane solvent systems were used instead of HMPA/toluene. Single crystal X-ray analysis confirmed the structure of both isomers and the configuration of their chiral centers. Results: In the radioligand replacement assay, both isomers showed strong affinity toward the CB1 receptor, with IC50=29.1 nM for the trans isomer and IC50=294.2 nM for the cis counterpart. However, the IC50 values were significantly higher than that of Δ9-THC (2.1 nM), a naturally occurring psychoactive component of cannabis sativa, suggesting a lower affinity of Δ10-THCs toward this receptor. In function assays, in contrast to Δ9-THC, both isomers failed to show any agonist properties at concentrations up to 10 μM suggesting a lack of THC-like psychoactivity for trans- and cis-Δ10-THC. Conclusions: Our results established Δ10-THC isomers among antagonists of the CB1 receptor as both cis and trans isomers antagonized CP55,490 with IC50=460 nM for trans and IC50=1040 nM for cis. This functional property has not been previously observed for any other THC isomers.

ПАРАМЕТРЫ ПОХОДКИ КРЫС С ПЕРИФЕРИЧЕСКОЙ НЕЙРОПАТИЕЙ ПРИ ТРАНСПЛАНТАЦИИ МЕЗЕНХИМАЛЬНЫХ СТВОЛОВЫХ КЛЕТОК И ФАРМАКОЛОГИЧЕСКОЙ СТИМУЛЯЦИИ КАННАБИНОИДНЫХ РЕЦЕПТОРОВ II ТИПА

Background. The study of the role of cannabinoid CB2 receptors in the effectiveness of adipose-derived (AD) mesenchymal stem cells (MSCs) in preventing motor activity disorders in the affected limb will deepen understanding of the mechanisms of MSCs effects when administered locally. Aim. To evaluate the effect of pharmacological stimulation of cannabinoid CB2 receptors during transplantation of AD MSCs on changes in gait parameters in rats in a model of peripheral neuropathy. Material and methods. In 40 male Wistar rats peripheral neuropathic pain was modeled by sciatic nerve transection. On the 7th day after NP modeling, AD MSCs transplantation was performed without additional interventions upon the pharmacological stimulation of CB2 receptors in the area of sciatic nerve transection, as well as after stimulation of CB2 receptors on the AD MSCs membranes during pretreatment. Within 90 days a detailed analysis of the gait was carried out using the CatWalk XT 10.6. Results. Transplantation of AD MSCs accelerated the recovery of dynamic gait parameters, as well as sciatic functional index, and abolished the development of static gait disturbances in rats after sciatic nerve transection. Significant differences in the analyzed gait parameters in the study groups with AD MSCs transplantation were not found. Conclusion. Pharmacological stimulation of CB2 receptors did not enhance or suppress the effect of AD MSCs on the rate of recovery of gait parameters in experimental animals.

Rational Design, Synthesis, and Evaluation of Fluorescent CB2 Receptor Ligands for Live-Cell Imaging: A Comprehensive Review.

The cannabinoid receptors CB1 and CB2 are class A G protein-coupled receptors (GPCRs) that are activated via endogenous lipids called endocannabinoids. The endocannabinoid system (ECS) plays a critical role in the regulation of several physiological states and a wide range of diseases. In recent years, drug discovery approaches targeting the cannabinoid type 2 receptor (CB2R) have gained prominence. Particular attention has been given to selective agonists targeting the CB2 receptors to circumvent the neuropsychotropic side effects associated with CB1 receptors. The pharmacological modulation of CB2R holds therapeutic promise for various diseases, such as inflammatory disorders and immunological conditions, as well as pain management and cancer treatment. Recently, the utilization of fluorescent probes has emerged as a valuable technique for investigating the interactions between ligands and proteins at an exceptional level of spatial and temporal precision. In this review, we aim to examine the progress made in the development of fluorescent probes targeting CB2 receptors and highlight their significance in facilitating the successful clinical translation of CB2R-based therapies.

Anorectic effect of COR659 in a rat model of overeating.

COR659 is a new compound, the action of which is exerted via a dual mechanism: positive allosteric modulation of the GABAB receptor; antagonism or inverse agonism at the cannabinoid CB1 receptor. Recent lines of experimental evidence have indicated that COR659 potently and effectively reduced operant self-administration of and reinstatement of seeking behaviour for a chocolate-flavoured beverage. The present study was designed to assess whether the ability of COR659 to diminish these addictive-like, food-motivated behaviours extended to a rat model of overeating palatable food. To this end, rats were habituated to feed on a standard rat chow for 3 h/day; every 4 days, the 3-hour chow-feeding session was followed by a 1-hour feeding session with highly palatable, calorie-rich Danish butter cookies. Even though satiated, rats overconsumed cookies. COR659 (0, 2.5, 5, and 10 mg/kg, i.p.) was administered before the start of the cookie-feeding session. Treatment with all 3 doses of COR659 produced a substantial decrease in intake of cookies and calories from cookies. These results extend the anorectic profile of COR659 to overconsumption of a highly palatable food and intake of large amounts of unnecessary calories.

The Leu/Val6.51 Side Chain of Cannabinoid Receptors Regulates the Binding Mode of the Alkyl Chain of Δ9-Tetrahydrocannabinol.

(-)-Δ9-trans-tetrahydrocannabinol (THC), which is the principal psychoactive constituent of Cannabis, mediates its action by binding to two members of the G-protein-coupled receptor (GPCR) family: the cannabinoid CB1 (CB1R) and CB2 (CB2R) receptors. Molecular dynamics simulations showed that the pentyl chain of THC could adopts an I-shape conformation, filling an intracellular cavity between Phe3.36 and Trp6.48 for initial agonist-induced receptor activation, in CB1R but not in CB2R. This cavity opens to the five-carbon chain of THC by the conformational change of the γ-branched, flexible, Leu6.51 side chain of CB1R, which is not feasible by the β-branched, mode rigid, Val6.51 side chain of CB2R. In agreement with our computational results, THC could not decrease the forskolin-induced cAMP levels in cells expressing mutant CB1RL6.51V receptor but could activate the mutant CB2RV6.51L receptor as efficiently as wild-type CB1R. Additionally, JWH-133, a full CB2R agonist, contains a branched dimethyl moiety in the ligand chain that bridges Phe3.36 and Val6.51 for receptor activation. In this case, the substitution of Val6.51 to Leu in CB2R makes JWH-133 unable to activate CB2RV6.51L. In conclusion, our combined computational and experimental results have shown that the amino acid at position 6.51 is a key additional player in the initial mechanism of activation of GPCRs that recognize signaling molecules derived from lipid species.

The role of cannabinoid CB1 receptors in the antinociceptive and reparative actions of mesenchymal stem cells in rats with peripheral neuropathic pain.

Mesenchymal stem cells (MSCs) can produce antinociceptive and reparative effects. Presumably, the MSCs-induced antinociception may be partly due to the involvement of the endocannabinoid system. The study aimed to evaluate the antinociceptive and reparative effects of adipose-derived MSCs (ADMSCs) upon pharmacological modulation of cannabinoid CB1 receptor in peripheral tissues or on ADMSCs' membranes in a rat model of peripheral neuropathy. ADMSCs were injected into the area of rat sciatic nerve injury (i) with no additional treatments, (ii) at the tissue CB1 receptor activation by endogenous agonist anandamide (AEA) or blockade with a selective AM251 antagonist; and (iii) preincubated with AEA or AM251. The evaluation of CB1 receptor activity involved analyzing nociceptive responses, gait parameters, and histology. Transplantation of ADMSCs upon activation of CB1 receptors, both on AMSCs' membranes or in the area of nerve injury, accelerated the analgesia and recovery of dynamic gait parameters, abolished static gait disturbances, and promoted the fastest nerve regeneration. Only blockade of CB1 receptors on ADMSCs shortened ADMSCs-induced analgesia and decreased the number of preserved nerve fibers. CB1 receptors on ADMSCs significantly contribute to their pain-relieving and tissue-repairing capabilities by stimulating the growth factors secretion and suppressing the release of pro-inflammatory cytokines. Peripheral CB1 receptors do not significantly influence ADMSC-induced antinociception.

Structural basis of selective cannabinoid CB2 receptor activation

Structural basis of selective cannabinoid CB2 receptor activation