Cannabinoid receptors and their endogenous agonists

Cannabis in combat sports: position statement of the Association of Ringside Physicians

and ARP Position Statement: Based on the available body of scientific evidence and with the goals of promoting safety of combat sports athletes and striving for the advancement of clean sport, the Association of Ringside Physicians recommends the following regarding cannabis:• Use of marijuana or synthetic cannabinoids by combat sports athletes is discouraged due to unproven benefits and many known adverse effects. Acute use can impair cognition and complex motor function, which likely leads to reduced performance in combat sports. Chronic use can increase risk for heart and lung disease, several cancers, schizophrenia, and can reduce testosterone in men and impair fertility. Benefits from cannabis in most contexts, including athletic performance, have not been proven.• Use of topical purified CBD is neither encouraged nor discouraged.• Since acute cannabis intoxication can impair complex cognitive and motor function, any athlete suspected of acute intoxication at the time of competition - based on clinical judgment - should be banned from that competition.• Wide-scale regulation of cannabis based on quantitative testing has limited usefulness in combat sports, for the following reasons:∘ Cannabis is not ergogenic and is likely ergolytic.∘ Concentrations in body fluids correlate poorly with clinical effects and timing of use.∘ Access to testing resources varies widely across sporting organizations.

Oral health status among recreational cannabis (marijuana and hashish) users in the USA: A NHANES-based cross-sectional study

Background

As of November 2023, twenty-four states, two territories, and DC have legalized marijuana for non-medical use, leading to concerns about its potential oral health effects. This study investigated the association between marijuana use and clinical dental outcomes among adults in the US.

Methods

We analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 2015 to 2018 using a cross-sectional survey of non-institutionalized US civilians. Marijuana use was assessed among 18-59-year-old adults and categorized as never, former, or current frequent use. The dental outcomes included the prevalence of untreated coronal caries, root caries, and missing teeth. We employed logistic and negative binomial regressions to assess the crude and adjusted associations between marijuana use, dental caries, and tooth loss.

Results

Of the 6,424 participants, 13.85% of US adults aged 18-59 years were current frequent marijuana users (21.67 million), with the highest prevalence among 18-29-year-olds (21.31%), males (17.54%), and non-Hispanic Black individuals (21.31%). Frequent marijuana users showed the highest prevalence of untreated coronal caries (33.4%). Before adjusting for socioeconomic confounders, current frequent marijuana users had 1.76 times higher odds of having teeth with coronal caries, whereas former frequent users had 1.47 times higher odds. However, the associations between marijuana use and all dental outcomes were attenuated after adjusting for socioeconomic confounders, tobacco use, and access to dental care.

Conclusion

Although marijuana use was associated with worse dental health, socioeconomic factors, tobacco use, and access to dental care were more significant contributors to the prevalence of untreated dental caries and missing teeth than marijuana use alone.

Silva H, P. de Carvalho R, Ventura ALM, Calaza KC, Silveira MS, Kubrusly RCC, de Melo Reis RA. The Healthy and Diseased Retina Seen through Neuron-Glia Interactions

The retina is the sensory tissue responsible for the first stages of visual processing, with a conserved anatomy and functional architecture among vertebrates. To date, retinal eye diseases, such as diabetic retinopathy, age-related macular degeneration, retinitis pigmentosa, glaucoma, and others, affect nearly 170 million people worldwide, resulting in vision loss and blindness. To tackle retinal disorders, the developing retina has been explored as a versatile model to study intercellular signaling, as it presents a broad neurochemical repertoire that has been approached in the last decades in terms of signaling and diseases. Retina, dissociated and arranged as typical cultures, as mixed or neuron- and glia-enriched, and/or organized as neurospheres and/or as organoids, are valuable to understand both neuronal and glial compartments, which have contributed to revealing roles and mechanisms between transmitter systems as well as antioxidants, trophic factors, and extracellular matrix proteins. Overall, contributions in understanding neurogenesis, tissue development, differentiation, connectivity, plasticity, and cell death are widely described. A complete access to the genome of several vertebrates, as well as the recent transcriptome at the single cell level at different stages of development, also anticipates future advances in providing cues to target blinding diseases or retinal dysfunctions.

Cannabidiol at Nanomolar Concentrations Negatively Affects Signaling through the Adenosine A2A Receptor

Cannabidiol (CBD) is a phytocannabinoid with potential as a therapy for a variety of diseases. CBD may act via cannabinoid receptors but also via other G-protein-coupled receptors (GPCRs), including the adenosine A2A receptor. Homogenous binding and signaling assays in Chinese hamster ovary (CHO) cells expressing the human version of the A2A receptor were performed to address the effect of CBD on receptor functionality. CBD was not able to compete for the binding of a SCH 442416 derivative labeled with a red emitting fluorescent probe that is a selective antagonist that binds to the orthosteric site of the receptor. However, CBD reduced the effect of the selective A2A receptor agonist, CGS 21680, on Gs-coupling and on the activation of the mitogen activated kinase signaling pathway. It is suggested that CBD is a negative allosteric modulator of the A2A receptor.

Cannabinoids function in defense against chewing herbivores in Cannabis sativa L

In the decades since the first cannabinoids were identified by scientists, research has focused almost exclusively on the function and capacity of cannabinoids as medicines and intoxicants for humans and other vertebrates. Very little is known about the adaptive value of cannabinoid production, though several hypotheses have been proposed including protection from ultraviolet radiation, pathogens, and herbivores. To test the prediction that genotypes with greater concentrations of cannabinoids will have reduced herbivory, a segregating F2 population of Cannabis sativa was leveraged to conduct lab- and field-based bioassays investigating the function of cannabinoids in mediating interactions with chewing herbivores. In the field, foliar cannabinoid concentration was inversely correlated with chewing herbivore damage. On detached leaves, Trichoplusia ni larvae consumed less leaf area and grew less when feeding on leaves with greater concentrations of cannabinoids. Scanning electron and light microscopy were used to characterize variation in glandular trichome morphology. Cannabinoid-free genotypes had trichomes that appeared collapsed. To isolate cannabinoids from confounding factors, artificial insect diet was amended with cannabinoids in a range of physiologically relevant concentrations. Larvae grew less and had lower rates of survival as cannabinoid concentration increased. These results support the hypothesis that cannabinoids function in defense against chewing herbivores.

Molecular insights into GPCR mechanisms for drugs of abuse

Substance abuse is on the rise, and while many people may use illicit drugs mainly due to their rewarding effects, their societal impact can range from severe, as is the case for opioids, to promising, as is the case for psychedelics. Common with all these drugs' mechanisms of action are G protein-coupled receptors (GPCRs), which lie at the center of how these drugs mediate inebriation, lethality, and therapeutic effects. Opioids like fentanyl, cannabinoids like tetrahydrocannabinol, and psychedelics like lysergic acid diethylamide all directly bind to GPCRs to initiate signaling which elicits their physiological actions. We herein review recent structural studies and provide insights into the molecular mechanisms of opioids, cannabinoids, and psychedelics at their respective GPCR subtypes. We further discuss how such mechanistic insights facilitate drug discovery, either toward the development of novel therapies to combat drug abuse or toward harnessing therapeutic potential.

Endocannabinoid-Binding Receptors as Drug Targets

Cannabis plant has been used from ancient times with therapeutic purposes for treating human pathologies, but the identification of the cellular and molecular mechanisms underlying the therapeutic properties of the phytocannabinoids, the active compounds in this plant, occurred in the last years of the past century. In the late 1980s and early 1990s, seminal studies demonstrated the existence of cannabinoid receptors and other elements of the so-called endocannabinoid system. These G protein-coupled receptors (GPCRs) are a key element in the functions assigned to endocannabinoids and appear to serve as promising pharmacological targets. They include CB₁, CB₂, and GPR55, but also non-GPCRs can be activated by endocannabinoids, like ionotropic receptor TRPV₁ and even nuclear receptors of the PPAR family. Their activation, inhibition, or simply modulation have been associated with numerous physiological effects at both central and peripheral levels, which may have therapeutic value in different human pathologies, then providing a solid experimental explanation for both the ancient medicinal uses of Cannabis plant and the recent advances in the development of cannabinoid-based specific therapies. This chapter will review the scientific knowledge generated in the last years around the research on the different endocannabinoid-binding receptors and their signaling mechanisms. Our intention is that this knowledge may help readers to understand the relevance of these receptors in health and disease conditions, as well as it may serve as the theoretical basis for the different experimental protocols to investigate these receptors and their signaling mechanisms that will be described in the following chapters.

Expression of cannabinoid receptors CB1 and CB2 in canine cutaneous mast cell tumours

Cannabinoid receptors (CB1 and CB2) belong to endocannabinoid system (ECS), which is also composed from endocannabinoids and the enzymatic systems involved in their biosynthesis and degradation. The expression of CB1 and CB2 have been previously identified in normal canine mast cell and in atopic dermatitis. Canine cutaneous mast cell tumours (cMCTs) are among the most common cutaneous neoplasms in dogs and have a highly variable clinical behaviour. Expression of CB1-CB2 was assessed by means of immunohistochemistry in thirty-seven dogs (from 2019 to 2021) with proven histological diagnosis of cMCT. Dogs were divided in two groups according to the Kiupel's grading system: high-grade (HG) cMCT and low-grade (LG) cMCT. A semiquantitative (score 0-3) and quantitative assessment of immunoreactivity (IR) was performed for each case. Our results show that there CB1 and CB2 are highly expressed in LG- cMCT, in contrast to HG- cMCT.

CB2 receptor activation inhibits the phagocytic function of microglia through activating ERK/AKT-Nurr1 signal pathways

Neuroinflammation is closely related to the pathogenesis of neurodegenerative diseases. Activation of microglia, the resident immune cells in CNS, induces inflammatory responses, resulting in the release of neurotoxic molecules, which favors neuronal death and neurodegeneration. Nuclear receptor-related 1 (Nurr1) protein, one of the orphan nuclear receptor superfamilies, is an emerging target for neuroprotective therapy. In addition, the anti-inflammatory function of cannabinoid (CB) receptors has attracted increasing interest. As both CB receptors (especially CB2 receptor) and Nurr1 exist in microglia, and regulate a number of same molecular points such as NF-κB, we herein explored the interplay between the CB2 receptor and Nurr1 as well as the regulatory mechanisms in microglial cells. We showed that the application of CB2 receptor agonists JWH015 (1, 10 μM) significantly increased the nuclear Nurr1 protein in BV-2 cells and primary midbrain microglia. Overexpression of Nurr1 or application of Nurr1 agonist C-DIM12 (10 μM) significantly increased the mRNA level of CB2 receptor in BV-2 cells, suggesting that positive expression feedback existing between the CB2 receptor and Nurr1. After 2-AG and JWH015 activated the CB2 receptors, the levels of p-ERK, p-AKT, p-GSK-3β in BV-2 cells were significantly increased. Using ERK1/2 inhibitor U0126 and PI3K/AKT inhibitor LY294002, we revealed that the amount of Nurr1 in the nucleus was upregulated through β-arrestin2/ERK1/2 and PI3K/AKT/GSK-3β signaling pathways. With these inhibitors, we found a cross-talk interaction between the two pathways, and the ERK1/2 signaling pathway played a more dominant regulatory role. Furthermore, we demonstrated that when the CB2 receptor was activated, the phagocytic function of BV-2 cells was significantly weakened; the activation of Nurr1 also inhibited the phagocytic function of BV-2 cells. Pretreatment with the signaling pathway inhibitors, especially U0126, reversed the inhibitory effect of 2-AG on phagocytosis, suggesting that CB2 receptor may regulate the phagocytic function of microglia by activating Nurr1. In conclusion, CB2 receptor or/and Nurr1-mediated signal pathways play instrumental roles in the progress of phagocytosis, which are expected to open up new treatment strategies for neurodegenerative diseases.

Reduced Endocannabinoid Tone in Saliva of Chronic Orofacial Pain Patients

Background: the endocannabinoid system (ECS) participates in many physiological and pathological processes including pain generation, modulation, and sensation. Its involvement in chronic orofacial pain (OFP) in general, and the reflection of its involvement in OFP in salivary endocannabinoid (eCBs) levels in particular, has not been examined. Objectives: to evaluate the association between salivary (eCBs) levels and chronic OFP. Methods: salivary levels of 2 eCBs, anandamide (AEA), 2-arachidonoylglycerol (2-AG), 2 endocannabinoid-like compoundsN-palmitoylethanolamine (PEA), N-oleoylethanolamine (OEA), and their endogenous precursor and breakdown product, arachidonic acid (AA), were analyzed using liquid chromatography/tandem mass spectrometry in 83 chronic OFP patients and 43 pain-free controls. The chronic OFP patients were divided according to diagnosis into musculoskeletal, neurovascular/migraine, and neuropathic pain types. Results: chronic OFP patients had lower levels of OEA (p = 0.02) and 2-AG (p = 0.01). Analyzing specific pain types revealed lower levels of AEA and OEA in the neurovascular group (p = 0.04, 0.02, respectively), and 2-AG in the neuropathic group compared to controls (p = 0.05). No significant differences were found between the musculoskeletal pain group and controls. Higher pain intensity was accompanied by lower levels of AA (p = 0.028), in neuropathic group. Conclusions: lower levels of eCBs were found in the saliva of chronic OFP patients compared to controls, specifically those with neurovascular/migraine, and neuropathic pain. The detection of changes in salivary endocannabinoids levels related to OFP adds a new dimension to our understanding of OFP mechanisms, and may have diagnostic as well as therapeutic implications for pain.

Frustrative nonreward and cannabinoid receptors: Chronic (but not acute) WIN 55,212-2 treatment increased resistance to change in two reward downshift tasks

Assessing the role of cannabinoid (CB) receptors in behavior is relevant given the trend toward the legalization of medicinal and recreational marijuana. The present research aims at bridging a gap in our understanding of CB-receptor function in animal models of frustrative nonreward. These experiments were designed to (1) determine the effects of chronic administration of the nonselective CB1-receptor agonist WIN 55,212-2 (WIN) on reward downshift in rats and (2) determine whether the effects of chronic WIN were reducible to acute effects. In Experiment 1, chronic WIN (7 daily injections, 10 mg/kg, ip) accelerated the recovery of consummatory behavior after a 32-to-4% sucrose downshift relative to vehicle controls. In addition, chronic WIN eliminated the preference for an unshifted lever when the other lever was subject to a 12-to-2 pellet downshift in free-choice trials, but only in animals with previous experience with a sucrose downshift. In Experiment 2, acute WIN (1 mg/kg, ip) reduced consummatory behavior, but did not affect recovery from a 32-to-4% sucrose downshift. The antagonist SR 141716A (3 mg/kg, ip) also failed to interfere with recovery after the sucrose downshift. In Experiment 3, acute WIN administration (1 mg/kg, ip) did not affect free-choice behavior after a pellet downshift, although it reduced lever pressing and increased magazine entries relative to vehicle controls. The effects of chronic WIN on frustrative nonreward were not reducible to acute effects of the drug. Chronic WIN treatment in rats, like chronic marijuana use in humans, seems to increase resistance to the effects of frustrative nonreward.

Parkinson's disease related alterations in cannabinoid transmission

Parkinson's disease (PD) is characterized by the progressive loss of dopaminergic (DAergic) neurons of the substantia nigra pars compacta (SNc) by neurodegeneration. Recent findings in animal models of PD propose tonic inhibition of the remaining DA neurons through GABA release from reactive glial cells. Movement dysfunctions could be ameliorated by promotion of activity in dormant DA cells. The endocannabinoid system (ECS) is extensively present in basal ganglia (BG) and is known as an indirect modulator of DAergic neurotransmission, thus drugs designed to target this system have shown promising therapeutic potential in PD patients. Interestingly, down/up-regulation of cannabinoid receptors (CBRs) varies across the different stages of PD, suggesting that some of the motor/ non-motor deficits may be related to changes in CBRs. Determination of the profile of changes of these receptors across the different stages of PD as well as their neural distribution within the BG could improve understanding of PD and identify pathways important in disease pathobiology. In this review, we focus on temporal and spatial alterations of CBRs during PD in the BG. At present, as inconclusive, but suggestive results have been obtained, future investigations should be conducted to extend preclinical studies examining CBRs changes within each stage in controlled clinical trials in order to determine the potential of targeting CBRs in management of PD.

Sequence similarity in 3D for comparison of protein families

Homologous proteins are often compared by pairwise sequence alignment, and structure superposition if the atomic coordinates are available. Unification of sequence and structure data is an important task in structural biology. Here, we present the Sequence Similarity 3D (SS3D) method of integrating sequence and structure information. SS3D is a distance and substitution matrix-based method for straightforward visualization of regions of similarity and difference between homologous proteins. This work details the SS3D approach, and demonstrates its utility through case studies comparing members of several protein families. The examples show that SS3D can effectively highlight biologically important regions of similarity and dissimilarity. We anticipate that the method will be useful for numerous structural biology applications, including, but not limited to, studies of binding specificity, structure-function relationships, and evolutionary pathways. SS3D is available with a manual and tutorial at https://github.com/0x462e41/SS3D/.

The impact of medical cannabis consumption on the oral flora and saliva

OBJECTIVE

To evaluate the effect of medical cannabis consumption on oral flora and saliva.

DESIGN

A clinical prospective study, at the rheumatology clinic of the Nazareth Hospital in Nazareth, recruiting consecutively patients approved for medical cannabis, evaluating their saliva flow, pH and microbial load of Streptococcus mutans and Lactobacillus, prior to and under medical cannabis treatment.

METHODS

Patients recently licensed for medical cannabis treatment, were recruited just prior to starting medical cannabis consumption (week 0), 1 and 4 weeks later, patients provided 5-minute time saliva samples, which were measured for their volume and pH, and cultured on a special microbial kit, evaluating the growth of Streptococcus mutans and Lactobacillus.

RESULTS

Out of 16 patients enrolled, 14 were female and had fibromyalgia. The mean age of the patients was 52.8±12.9 years. The mean saliva flow at week 0, week 1 and week 4 were 5.38±3.36 ml/5-minutes, 6 (p = 0.769) and 5.45 (p = 0.391), respectively, and for saliva pH were 6.28, 5.94 (p = 0.51) and 5.5 (p = 0.07) respectively also. The mean Streptococcus mutans growth score at weeks 0, 1 and 4 was1.8±0.75, 1.6±0.83 (p = 0.234), and 2.4±0.84 (p = 0.058), respectively. The mean Lactobacilli growth score at weeks 0, 1 and 4 was 2.59±0.88, 3.1±0.69 (p = 0.033) and 3.3±0.67 (p = 0.025), respectively.

CONCLUSIONS

The results of this study show that medical cannabis consumption has no significant effect on saliva volume or pH, but it may be associated with changes in salivary levels of oral microbes such as Streptococcus mutans and Lactobacilli.

Personality traits and polymorphisms of genes coding neurotransmitter receptors or transporters: review of single gene and genome-wide association studies

BACKGROUND

The most popular tool used for measuring personality traits is the Five-Factor Model (FFM). It includes neuroticism, extraversion, openness, agreeableness and conscientiousness. Many studies indicated the association of genes encoding neurotransmitter receptors/transporters with personality traits. The relationship connecting polymorphic DNA sequences and FFM features has been described in the case of genes encoding receptors of cannabinoid and dopaminergic systems. Moreover, dopaminergic system receives inputs from other neurotransmitters, like GABAergic or serotoninergic systems.

METHODS

We searched PubMed Central (PMC), Science Direct, Scopus, Cochrane Library, Web of Science and EBSCO databases from their inception to November 19, 2020, to identify original studies, as well as peer-reviewed studies examining the FFM and its association with gene polymorphisms affecting the neurotransmitter functions in central nervous system.

RESULTS

Serotonin neurons modulate dopamine function. In gene encoding serotonin transporter protein, SLC6A4, was found polymorphism, which was correlated with openness to experience (in Sweden population), and high scores of neuroticism and low levels of agreeableness (in Caucasian population). The genome-wide association studies (GWASs) found an association of 5q34-q35, 3p24, 3q13 regions with higher scores of neuroticism, extraversion and agreeableness. However, the results for chromosome 3 regions are inconsistent, which was shown in our review paper.

CONCLUSIONS

GWASs on polymorphisms are being continued in order to determine and further understand the relationship between the changes in DNA and personality traits.

Neurotoxicology Syndromes Associated with Drugs of Abuse

Substance use disorders-and their associated neurologic complications-are frequently encountered by neurologists as well as emergency room physicians, internists, psychiatrists, and medical intensivists. Prominent neurologic sequelae of drug abuse, such as seizure and stroke, are common and often result in patients receiving medical attention. However, less overt neurologic manifestations, such as dysautonomia and perceptual disturbances, may be initially misattributed to primary medical or psychiatric illness, respectively. This article focuses on the epidemiology, pharmacology, and complications associated with commonly used recreational drugs, including opioids, alcohol, marijuana, cocaine, and hallucinogens.

Resilience to fear: The role of individual factors in amygdala response to stressors

Resilience to stress is an adaptive process that varies individually. Resilience refers to the adaptation, or the ability to maintain or regain mental health, despite being subject to adverse situation. Resilience is a dynamic concept that reflects a combination of internal individual factors, including age and gender interacting with external factors such as social, cultural and environmental factors. In the last decade, we have witnessed an increase in the prevalence of anxiety disorders, including post-traumatic stress disorder. Given that stress in unavoidable, it is of great interest to understand the neurophysiological mechanisms of resilience, the individual factors that may contribute to susceptibility and promote efficacious approaches to improve resilience. Here, we address this complex question, attempting at defining clear and operational definitions that may allow us to improve our analysis of behavior incorporating individuality. We examine how individual perception of the stressor can alter the outcome of an adverse situation using as an example, the fear-conditioning paradigm and discuss how individual differences in the reward system can contribute to resilience. Given the central role of the endocannabinoid system in regulating fear responses and anxiety, we discuss the evidence that polymorphisms in several molecules of this signaling system contribute to different anxiety phenotypes. The endocannabinoid system is highly interconnected with the serotoninergic and dopaminergic modulatory systems, contributing to individual differences in stress perception and coping mechanisms. We review how the individual variability in these modulatory systems can be used towards a multivariable assessment of stress risk. Incorporating individuality in our research will allow us to define biomarkers of anxiety disorders as well as assess prognosis, towards a personalized clinical approach to mental health.

Cellular and behavioral basis of cannabinioid and opioid interactions: Implications for opioid dependence and withdrawal

The brain's endogenous opioid and endocannabinoid systems are neuromodulatory of synaptic transmission, and play key roles in pain, memory, reward, and addiction. Recent clinical and pre-clinical evidence suggests that opioid use may be reduced with cannabinoid intake. This suggests the presence of a functional interaction between these two systems. Emerging research indicates that cannabinoids and opioids can functionally interact at different levels. At the cellular level, opioid and cannabinoids can have direct receptor associations, alterations in endogenous opioid peptide or cannabinoid release, or post-receptor activation interactions via shared signal transduction pathways. At the systems level, the nature of cannabinoid and opioid interaction might differ in brain circuits underlying different behavioral phenomenon, including reward-seeking or antinociception. Given the rising use of opioid and cannabinoid drugs, a better understanding of how these endogenous signaling systems interact in the brain is of significant interest. This review focuses on the potential relationship of these neural systems in addiction-related processes.

Molecular Mechanisms for the Inflammation-Resolving Actions of Lenabasum

A first-in-class cannabinoid analog called lenabasum that is a CB2 agonist is being developed as an inflammation-resolving drug candidate. Thus far, specific therapeutic targets include scleroderma, cystic fibrosis, dermatomyositis, and lupus, all of which represent unmet medical needs. Two somewhat-independent molecular mechanisms for this type of action are here proposed. Both pathways initially involve the release of free arachidonic acid after activation of the CB2 receptor and phospholipase A2 by lenabasum. The pathways then diverge into a cyclooxygenase 2-mediated and a lipoxygenase-mediated route. The former leads to increased levels of the cyclopentenone prostaglandin 15-deoxy-Δ^12,14-prostaglandin-J₂ that can activate the NLPR3 inflammasome, which in turn releases caspase-3, leading to apoptosis and the resolution of chronic inflammation. The lipoxygenase-mediated pathway stimulates the production of lipoxin A₄ as well as other signaling molecules called specialized proresolving mediators. These also have inflammation-resolving actions. It is not well understood under which conditions each of these mechanisms operates and whether there is crosstalk between them. Thus, much remains to be learned about the mechanisms describing the actions of lenabasum. SIGNIFICANCE STATEMENT: The resolution of chronic inflammation is a major unmet medical need. The synthetic nonpsychoactive cannabinoid lenabasum could provide a safe and effective drug for this purpose. Two putative molecular mechanisms are suggested to better understand how lenabasum produces this action. In both, different metabolites of arachidonic acid act as mediators.

20 Years an Orphan: Is GPR84 a Plausible Medium-Chain Fatty Acid-Sensing Receptor?

GPR84 is an inflammation-induced receptor highly expressed on immune cells, yet its endogenous ligand is still unknown. This makes any interpretation of its physiological activity in vivo difficult. However, experiments with potent synthetic agonists have highlighted what the receptor can do, namely, enhance proinflammatory signaling and macrophage effector functions such as phagocytosis. Developing drugs to block these effects has attracted interest from the scientific community with the aim of decreasing disease activity in inflammatory disorders or enhancing inflammation resolution. In this review, we critically reassess the widely held belief that the major role of GPR84 is that of being a medium-chain fatty acid (MCFA) receptor. While MCFAs have been shown to activate GPR84, it remains to be demonstrated that they are present in relevant tissues at appropriate concentrations. In contrast to four other "full-time" free fatty acid receptor subtypes, GPR84 is not expressed by enteroendocrine cells and has limited expression in the gastrointestinal tract. Across multiple tissues and cell types, the highest expression levels of GPR84 are observed hours after exposure to an inflammatory stimulus. These factors obscure the relationship between ligand and receptor in the human body and do not support the exclusive physiological pairing of MCFAs with GPR84. To maximize the chances of developing efficacious drugs for inflammatory diseases, we must advance our understanding of GPR84 and what it does in vivo.

Cannabinoid receptor CNR1 expression and DNA methylation in human prefrontal cortex, hippocampus and caudate in brain development and schizophrenia

Beyond being one the most widely used psychoactive drugs in the world, cannabis has been identified as an environmental risk factor for psychosis. Though the relationship between cannabis use and psychiatric disorders remains controversial, consistent association between early adolescent cannabis use and the subsequent risk of psychosis suggested adolescence may be a particularly vulnerable period. Previous findings on gene by environment interactions indicated that cannabis use may only increase the risk for psychosis in the subjects who have a specific genetic vulnerability. The type 1 cannabinoid receptor (CB1), encoded by the CNR1 gene, is a key component of the endocannabinoid system. As the primary endocannabinoid receptor in the brain, CB1 is the main molecular target of the endocannabinoid ligand, as well as tetrahydrocannabinol (THC), the principal psychoactive ingredient of cannabis. In this study, we have examined mRNA expression and DNA methylation of CNR1 in human prefrontal cortex (PFC), hippocampus, and caudate samples. The expression of CNR1 is higher in fetal PFC and hippocampus, then drops down dramatically after birth. The lifespan trajectory of CNR1 expression in the DLPFC differentially correlated with age by allelic variation at rs4680, a functional polymorphism in the COMT gene. Compared with COMT methionine¹⁵⁸ carriers, Caucasian carriers of the COMT valine¹⁵⁸ allele have a stronger negative correlation between the expression of CNR1 in DLPFC and age. In contrast, the methylation level of cg02498983, which is negatively correlated with the expression of CNR1 in PFC, showed the strongest positive correlation with age in PFC of Caucasian carriers of COMT valine¹⁵⁸. Additionally, we have observed decreased mRNA expression of CNR1 in the DLPFC of patients with schizophrenia. Further analysis revealed a positive eQTL SNP, rs806368, which predicted the expression of a novel transcript of CNR1 in human DLPFC, hippocampus and caudate. This SNP has been associated with addiction and other psychiatric disorders. THC or ethanol are each significantly associated with dysregulated expression of CNR1 in the PFC of patients with affective disorder, and the expression of CNR1 is significantly upregulated in the PFC of schizophrenia patients who completed suicide. Our results support previous studies that have implicated the endocannabinoid system in the pathology of schizophrenia and provided additional insight into the mechanism of increasing risk for schizophrenia in the adolescent cannabis users.

Cannabinoids as anticancer therapeutic agents

The recent announcement of marijuana legalization in Canada spiked many discussions about potential health benefits of Cannabis sativa. Cannabinoids are active chemical compounds produced by cannabis, and their numerous effects on the human body are primarily exerted through interactions with cannabinoid receptor types 1 (CB1) and 2 (CB2). Cannabinoids are broadly classified as endo-, phyto-, and synthetic cannabinoids. In this review, we will describe the activity of cannabinoids on the cellular level, comprehensively summarize the activity of all groups of cannabinoids on various cancers and propose several potential mechanisms of action of cannabinoids on cancer cells.

Interaction of Cannabis Use and Aging: From Molecule to Mind

Given the aging Baby Boomer generation, changes in cannabis legislation, and the growing acknowledgment of cannabis for its therapeutic potential, it is predicted that cannabis use in the older population will escalate. It is, therefore, important to determine the interaction between the effects of cannabis and aging. The aim of this report is to describe the link between cannabis use and the aging brain. Our review of the literature found few and inconsistent empirical studies that directly address the impact of cannabis use on the aging brain. However, research focused on long-term cannabis use points toward cumulative effects on multimodal systems in the brain that are similarly affected during aging. Specifically, the effects of cannabis and aging converge on overlapping networks in the endocannabinoid, opioid, and dopamine systems that may affect functional decline particularly in the hippocampus and prefrontal cortex, which are critical areas for memory and executive functioning. To conclude, despite the limited current knowledge on the potential interactive effects between cannabis and aging, evidence from the literature suggests that cannabis and aging effects are concurrently present across several neurotransmitter systems. There is a great need for future research to directly test the interactions between cannabis and aging.

Cannabidiol Regulates Gene Expression in Encephalitogenic T cells Using Histone Methylation and noncoding RNA during Experimental Autoimmune Encephalomyelitis

Cannabidiol (CBD) has been shown by our laboratory to attenuate experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). In this study, we used microarray and next generation sequencing (NGS)-based approaches to determine whether CBD would alter genome-wide histone modification and gene expression in MOG sensitized lymphocytes. We compared H3K4me3 and H3K27me3 marks in CD4+ T cells from naïve, EAE and CBD treated EAE mice by ChIP-seq. Although the overall methylation level of these two histone marks did not change significantly, the signal intensity and coverage differed in individual genes, suggesting that CBD may modulate gene expression by altering histone methylation. Further analysis showed that these histone methylation signals were differentially enriched in the binding sites of certain transcription factors, such as ZNF143 and FoxA1, suggesting that these transcription factors may play important roles in CBD mediated immune modulation. Using microarray analysis, we found that the expression pattern of many EAE-induced genes was reversed by CBD treatment which was consistent with its effect on attenuating the clinical symptoms of EAE. A unique finding of this study was that the expression of many miRNAs and lncRNAs was dramatically affected by CBD. In summary, this study demonstrates that CBD suppresses inflammation through multiple mechanisms, from histone methylation to miRNA to lncRNA.

Current Progress in Pharmacogenetics of Second-Line Antidiabetic Medications: Towards Precision Medicine for Type 2 Diabetes

Precision medicine is a scientific and medical practice for personalized therapy based on patients’ individual genetic, environmental, and lifestyle characteristics. Pharmacogenetics and pharmacogenomics are also rapidly developing and expanding as a key element of precision medicine, in which the association between individual genetic variabilities and drug disposition and therapeutic responses are investigated. Type 2 diabetes (T2D) is a chronic metabolic disorder characterized by hyperglycemia mainly associated with insulin resistance, with the risk of clinically important cardiovascular, neurological, and renal complications. The latest consensus report from the American Diabetes Association and European Association for the Study of Diabetes (ADA-EASD) on the management of T2D recommends preferential use of glucagon-like peptide-1 (GLP-1) receptor agonists, sodium-glucose cotransporter-2 (SGLT2) inhibitors, and some dipeptidyl peptidase-4 (DPP-4) inhibitors after initial metformin monotherapy for diabetic patients with established atherosclerotic cardiovascular or chronic kidney disease, and with risk of hypoglycemia or body weight-related problems. In this review article, we summarized current progress on pharmacogenetics of newer second-line antidiabetic medications in clinical practices and discussed their therapeutic implications for precision medicine in T2D management. Several biomarkers associated with drug responses have been identified from extensive clinical pharmacogenetic studies, and functional variations in these genes have been shown to significantly affect drug-related glycemic control, adverse reactions, and risk of diabetic complications. More comprehensive pharmacogenetic research in various clinical settings will clarify the therapeutic implications of these genes, which may be useful tools for precision medicine in the treatment and prevention of T2D and its complications.

Acute cannabis toxicity

Objective: We describe the clinical effects of, and products associated with, acute exposures to cannabis during the early legalization period of recreational cannabis in Oregon and Alaska. Methods: This was an observational study of Oregon/Alaska Poison Center data between 4 December 2015 and 15 April 2017. A standardized data collection instrument was created for this study that captured information about cannabis product description, route of exposure, intentional vs unintentional exposure, product dose, product manufacture source, product ownership source, initial vital signs, clinical signs and symptoms, and subject disposition. Subjects were included if the Poison Center received a call about an acute exposure to cannabis from the subject, subject's family member or friend, or healthcare worker participating in the subject's care. Subjects were excluded if there was no evident exposure, the exposure was chronic, there were co-ingestants, or the subject was non-human (e.g. pet). Results: Two hundred fifty three individuals were acutely exposed to cannabis (median age 20 years; range 8 months - 96 years; 54.2% males): 71 (28.1%) children (<12 years), 42 (16.6%) adolescents (12-17 years), and 140 (55.3%) adults (≥18 years). Children were most likely to unintentionally (98.6%) ingest (97.2%) homemade (35.2%) edibles (64.8%) belonging to a family member (73.2%) and experience sedation (52.1%). Adults were most likely to intentionally (88.6%) ingest (66.4%) retail (40.0%) edibles (48.6%) and experience neuroexcitation (47.1%). Adolescents' exposures had similarities to both adult and children; they were most likely to intentionally (81.0%) ingest (50.0%) homemade (23.8%) edibles (45.2%) belonging to a friend (47.3%) and to experience either neuroexcitation (42.9%) or sedation (40.5%). Among all ages, tachycardia and neuroexcitation were more likely following inhalation exposures compared to ingestions. Eight subjects were admitted to an intensive care unit, including three patients who were intubated; one subject died. Edibles were the most common products to cause symptoms in all age groups, while concentrated products were more likely to lead to intubation, especially when ingested. Children in particular had a higher likelihood of intensive care unit admission and intubation following exposure to concentrated products. Conclusions: Neurotoxicity is common after acute cannabis exposures. Children experienced unintentional exposures, particularly within the home and occasionally with major adverse outcomes. Concentrated products such as resins and liquid concentrates were associated with greater toxicity than other cannabis products. These findings may help guide other states during the early retail cannabis legalization period.

Structure of a Signaling Cannabinoid Receptor 1-G Protein Complex

Cannabis elicits its mood-enhancing and analgesic effects through the cannabinoid receptor 1 (CB1), a G protein-coupled receptor (GPCR) that signals primarily through the adenylyl cyclase-inhibiting heterotrimeric G protein G_i. Activation of CB1-G_i signaling pathways holds potential for treating a number of neurological disorders and is thus crucial to understand the mechanism of G_i activation by CB1. Here, we present the structure of the CB1-G_i signaling complex bound to the highly potent agonist MDMB-Fubinaca (FUB), a recently emerged illicit synthetic cannabinoid infused in street drugs that have been associated with numerous overdoses and fatalities. The structure illustrates how FUB stabilizes the receptor in an active state to facilitate nucleotide exchange in G_i. The results compose the structural framework to explain CB1 activation by different classes of ligands and provide insights into the G protein coupling and selectivity mechanisms adopted by the receptor.

An overview of the cannabinoid type 2 receptor system and its therapeutic potential

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.

Cannabinoid receptor 2 as a novel target for promotion of renal cell carcinoma prognosis and progression

PURPOSE

Renal cell carcinoma (RCC) is the most common malignancy of urogenital system, and patients with RCC may face a poor prognosis. However, limited curable therapeutic options are currently available. The aim of this study is to investigate the role of Cannabinoid receptor 2 (CB2) in RCC progression.

METHODS

Immunohistochemistry was to investigate the expression pattern of CB2 in 418 RCC tissues and explore its prognostic function in RCC patients. Furthermore, the role of used CB2 si-RNA knockdown and inhibited by AM630, a CB2 inverse agonist, on cell proliferation, migration, and cell cycle of RCC cell lines in vitro was also investigated.

RESULTS

We observed that CB2 was up-regulated in RCC tissues, and presented as an independent prognostic factor for overall survival of RCC patients and higher CB2 expression tends to have poor clinical outcomes in survival analyses. Moreover, we also observed that CB2, incorporated with pN stage, pathological grade, and recurrence or distant metastasis after surgery, could obviously enhance their prognostic accuracy in a predictive nomogram analysis. In addition, knockdown or inhibition by AM630 for the expression of CB2 in vitro could significantly decreased cell proliferation and migration, and obviously induced cell cycle arrest in G2/M of RCC cells.

CONCLUSIONS

CB2 expression is functionally related to cellular proliferation, migration, and cell cycle of RCC cells. Our data suggest that CB2 might be a potential therapeutic target for RCC.

Drugs as instruments: a new framework for non-addictive psychoactive drug use

Most people who are regular consumers of psychoactive drugs are not drug addicts, nor will they ever become addicts. In neurobiological theories, non-addictive drug consumption is acknowledged only as a "necessary" prerequisite for addiction, but not as a stable and widespread behavior in its own right. This target article proposes a new neurobiological framework theory for non-addictive psychoactive drug consumption, introducing the concept of "drug instrumentalization." Psychoactive drugs are consumed for their effects on mental states. Humans are able to learn that mental states can be changed on purpose by drugs, in order to facilitate other, non-drug-related behaviors. We discuss specific "instrumentalization goals" and outline neurobiological mechanisms of how major classes of psychoactive drugs change mental states and serve non-drug-related behaviors. We argue that drug instrumentalization behavior may provide a functional adaptation to modern environments based on a historical selection for learning mechanisms that allow the dynamic modification of consummatory behavior. It is assumed that in order to effectively instrumentalize psychoactive drugs, the establishment of and retrieval from a drug memory is required. Here, we propose a new classification of different drug memory subtypes and discuss how they interact during drug instrumentalization learning and retrieval. Understanding the everyday utility and the learning mechanisms of non-addictive psychotropic drug use may help to prevent abuse and the transition to drug addiction in the future.

Chronic Δ(9)-Tetrahydrocannabinol Administration Reduces IgE(+)B Cells but Unlikely Enhances Pathogenic SIVmac251 Infection in Male Rhesus Macaques of Chinese Origin

Delta9-tetrahydrocannabinol (Δ(9)-THC) is the major psychoactive component of the cannabis plant. Δ(9)-THC has been used in the active ingredient of Marinol as an appetite stimulant for AIDS patients. Its impact on progression of HIV-1 infection, however, remains debatable. Previous studies indicated that Δ(9)-THC administration enhanced HIV-1 infection in huPBL-SCID mice but seemingly decreased early mortality in simian immunodeficiency virus (SIV) infected male Indian-derived rhesus macaques. Here, we determine the chronic effect of Δ(9)-THC administration using 0.32 mg/kg or placebo (PBO), i.m., twice daily for 428 days on SIVmac251 infected male Chinese-derived rhesus macaques. Sixteen animals were divided into four study groups: Δ(9)-THC(+)SIV(+), Δ(9)-THC(+)SIV(-), PBO/SIV(+) and PBO/SIV(-) (n = 4/group). One-month after daily Δ(9)-THC or PBO administrations, macaques in groups one and three were challenged intravenously with pathogenic SIVmac251/CNS, which was isolated from the brain of a Chinese macaque with end-staged neuroAIDS. No significant differences in peak and steady state plasma viral loads were seen between Δ(9)-THC(+)SIV(+) and PBO/SIV(+) macaques. Regardless of Δ(9)-THC, all infected macaques displayed significant drop of CD4/CD8 T cell ratio, loss of CD4(+) T cells and higher persistent levels of Ki67(+)CD8(+) T cells compared with uninfected animals. Moreover, long-term Δ(9)-THC treatment reduced significantly the frequency of circulating IgE(+)B cells. Only one Δ(9)-THC(+)SIV(+) macaque died of simian AIDS with paralyzed limbs compared with two deaths in the PBO/SIV(+) group during the study period. These findings indicate that chronic Δ(9)-THC administration resulted in reduction of IgE(+)B cells, yet it unlikely enhanced pathogenic SIVmac251/CNS infection in male Rhesus macaques of Chinese origin.

Marijuana dependence: not just smoke and mirrors

Marijuana (Cannabis sativa) is the most commonly used illicit drug worldwide as well as in the Unites States. Prolonged use of marijuana or repeated administration of its primary psychoactive constituent, Δ9-tetrahydrocannabinol (THC), can lead to physical dependence in humans and laboratory animals. The changes that occur with repeated cannabis use include alterations in behavioral, physiological, and biochemical responses. A variety of withdrawal responses occur in cannabis-dependent individuals: anger, aggression, irritability, anxiety and nervousness, decreased appetite or weight loss, restlessness, and sleep difficulties with strange dreams. But the long half-life and other pharmacokinetic properties of THC result in delayed expression of withdrawal symptoms, and because of the lack of contiguity between drug cessation and withdrawal responses the latter are not readily recognized as a clinically relevant syndrome. Over the past 30 years, a substantial body of clinical and laboratory animal research has emerged supporting the assertion that chronic exposure to cannabinoids produces physical dependence and may contribute to drug maintenance in cannabis-dependent individuals. However, no medications are approved to treat cannabis dependence and withdrawal. In this review, we describe preclinical and clinical research that supports the existence of a cannabinoid withdrawal syndrome. In addition, we review research evaluating potential pharmacotherapies (e.g., THC, a variety of antidepressant drugs, and lithium) to reduce cannabis withdrawal responses and examine how expanded knowledge about the regulatory mechanisms in the endocannabinoid system may lead to promising new therapeutic targets.

Delta-9-tetrahydrocannabinol (THC) affects forelimb motor map expression but has little effect on skilled and unskilled behavior

It has previously been shown in rats that acute administration of delta-9-tetrahydrocannabinol (THC) exerts a dose-dependent effect on simple locomotor activity, with low doses of THC causing hyper-locomotion and high doses causing hypo-locomotion. However the effect of acute THC administration on cortical movement representations (motor maps) and skilled learned movements is completely unknown. It is important to determine the effects of THC on motor maps and skilled learned behaviors because behaviors like driving place people at a heightened risk. Three doses of THC were used in the current study: 0.2mg/kg, 1.0mg/kg and 2.5mg/kg representing the approximate range of the low to high levels of available THC one would consume from recreational use of cannabis. Acute peripheral administration of THC to drug naïve rats resulted in dose-dependent alterations in motor map expression using high resolution short duration intracortical microstimulation (SD-ICMS). THC at 0.2mg/kg decreased movement thresholds and increased motor map size, while 1.0mg/kg had the opposite effect, and 2.5mg/kg had an even more dramatic effect. Deriving complex movement maps using long duration (LD)-ICMS at 1.0mg/kg resulted in fewer complex movements. Dosages of 1.0mg/kg and 2.5mg/kg THC reduced the number of reach attempts but did not affect percentage of success or the kinetics of reaching on the single pellet skilled reaching task. Rats that received 2.5mg/kg THC did show an increase in latency of forelimb removal on the bar task, while dose-dependent effects of THC on unskilled locomotor activity using the rotorod and horizontal ladder tasks were not observed. Rats may be employing compensatory strategies after receiving THC, which may account for the robust changes in motor map expression but moderate effects on behavior.

Cannabinoids as therapeutic agents in cancer: current status and future implications

The pharmacological importance of cannabinoids has been in study for several years. Cannabinoids comprise of (a) the active compounds of the Cannabis sativa plant, (b) endogenous as well as (c) synthetic cannabinoids. Though cannabinoids are clinically used for anti-palliative effects, recent studies open a promising possibility as anti-cancer agents. They have been shown to possess anti-proliferative and anti-angiogenic effects in vitro as well as in vivo in different cancer models. Cannabinoids regulate key cell signaling pathways that are involved in cell survival, invasion, angiogenesis, metastasis, etc. There is more focus on CB1 and CB2, the two cannabinoid receptors which are activated by most of the cannabinoids. In this review article, we will focus on a broad range of cannabinoids, their receptor dependent and receptor independent functional roles against various cancer types with respect to growth, metastasis, energy metabolism, immune environment, stemness and future perspectives in exploring new possible therapeutic opportunities.

The role of cannabinoids in adult neurogenesis

The processes underpinning post-developmental neurogenesis in the mammalian brain continue to be defined. Such processes involve the proliferation of neural stem cells and neural progenitor cells (NPCs), neuronal migration, differentiation and integration into a network of functional synapses within the brain. Both intrinsic (cell signalling cascades) and extrinsic (neurotrophins, neurotransmitters, cytokines, hormones) signalling molecules are intimately associated with adult neurogenesis and largely dictate the proliferative activity and differentiation capacity of neural cells. Cannabinoids are a unique class of chemical compounds incorporating plant-derived cannabinoids (the active components of Cannabis sativa), the endogenous cannabinoids and synthetic cannabinoid ligands, and these compounds are becoming increasingly recognized for their roles in neural developmental processes. Indeed, cannabinoids have clear modulatory roles in adult neurogenesis, probably through activation of both CB1 and CB2 receptors. In recent years, a large body of literature has deciphered the signalling networks involved in cannabinoid-mediated regulation of neurogenesis. This timely review summarizes the evidence that the cannabinoid system is intricately associated with neuronal differentiation and maturation of NPCs and highlights intrinsic/extrinsic signalling mechanisms that are cannabinoid targets. Overall, these findings identify the central role of the cannabinoid system in adult neurogenesis in the hippocampus and the lateral ventricles and hence provide insight into the processes underlying post-developmental neurogenesis in the mammalian brain.

Effects of a High-Protein/Low-Carbohydrate versus a Standard Hypocaloric Diet on Weight and Cardiovascular Risk Factors during 9 Months: Role of a Genetic Variation in the Cannabinoid Receptor Gene (CNR1) (G1359A Polymorphism)

Objective: We decided to investigate the role of this polymorphism on cardiovascular risk factors and weight loss secondary to a high-protein/low-carbohydrate vs. a standard hypocaloric diet (1,000 kcal/day) over a period of 9 months. Material and methods: A nutritional evaluation was performed at the beginning and at the end of a 9-month period in which subjects received 1 of 2 diets (diet HP: high protein/low carbohydrate vs. S: standard diet). Results: One hundred and four patients (54.7%) had the genotype G1359G and 86 (45.3%) patients had G1359A (77 patients, 25.8%) or A1359A (9 patients, 3.7%) (A-allele-carriers). In subjects with both genotypes, the body mass index, weight, fat mass, waist circumference and systolic blood pressures decreased with both diets. After the diet type HP and in subjects with both genotypes, the glucose, leptin, total cholesterol, LDL-cholesterol, insulin and HOMA-R levels decreased. After diet S and in all subjects, the total cholesterol, LDL cholesterol and leptin levels decreased, too. Conclusion: Our interventional study didn't show a relationship between the rs1049353 CNR-1 polymorphism and body weight response after two different hypocaloric (low carbohydrate/high protein vs. standard) diets over a period of 9 months. However, a low-carbohydrate/high-protein diet for 9 months improved glucose metabolism in subjects with both genotypes.

Polymorphism G1359A of the cannabinoid receptor gene (CNR1): allelic frequencies and influence on cardiovascular risk factors in a multicentre study of Castilla-Leon

BACKGROUND

A polymorphism (1359 G/A) of the CNR1 gene was reported as a common polymorphism in Caucasian populations and was related to cardiovascular risk factors. The present study aimed to investigate the allelic distribution of polymorphism (G1359A) of the CB1 receptor gene in a geographical area of Spain (Community of Castilla y Leon) and to evaluate the influence of this polymorphism on obesity anthropometric parameters and cardiovascular risk factors in the fasted state in obese patients.

METHODS

A population of 341 obese subjects was analysed. Tetrapolar electrical bioimpedance measurement, blood pressure measurement, a serial assessment of nutritional intake with 3 days of written food records and a biochemical analysis were all performed.

RESULTS

One hundred and seventy-seven patients (51.9%) had the genotype G1359G (wild-type group) and 164 (48.1%) patients were A carriers: G1359A (136 patients; 39.9%) or A1359A (28 patients; 8.2%) (mutant type group). The Health Area of Palencia had a lower frequency of wild-type genotype and G allelic frequency than all the other Health Areas. Segovia and Burgos Areas had a higher frequency of wild-type genotype and G allelic frequency than the other Health Areas. High-density lipoprotein (HDL) cholesterol was higher in the mutant type group and blood tryglicerides were lower in the same group.

CONCLUSIONS

In conclusion, the novel finding of the present study is the association of the mutant type group G1359A and A1359A with a better lipid profile (triglycerides and HDL cholesterol) than the wild-type group. The frequencies of this polymorphism are different among Health Areas of Castilla y Leon (Spain).

Δ(9) Tetrahydrocannabinol attenuates Staphylococcal enterotoxin B-induced inflammatory lung injury and prevents mortality in mice by modulation of miR-17-92 cluster and induction of T-regulatory cells

BACKGROUND AND PURPOSE

Staphylococcal enterotoxin B (SEB) is a potent activator of Vβ8+T-cells resulting in the clonal expansion of ∼30% of the T-cell pool. Consequently, this leads to the release of inflammatory cytokines, toxic shock, and eventually death. In the current study, we investigated if Δ(9) tetrahydrocannabinol (THC), a cannabinoid known for its anti-inflammatory properties, could prevent SEB-induced mortality and alleviate symptoms of toxic shock.

EXPERIMENTAL APPROACH

We investigated the efficacy of THC against the dual administration (intranasal and i.p.) of SEB into C3H/HeJ mice based on the measurement of SEB-mediated clinical parameters, including cytokine production, cellular infiltration, vascular leak, and airway resistance. In addition, the molecular mechanism of action was elucidated in vitro by the activation of splenocytes with SEB.

KEY RESULTS

Exposure to SEB resulted in acute mortality, while THC treatment led to 100% survival of mice. SEB induced the miRNA-17-92 cluster, specifically miRNA-18a, which targeted Pten (phosphatase and tensin homologue), an inhibitor of the PI3K/Akt signalling pathway, thereby suppressing T-regulatory cells. In contrast, THC treatment inhibited the individual miRNAs in the cluster, reversing the effects of SEB.

CONCLUSIONS AND IMPLICATIONS

We report, for the first time a role for the miRNA 17-92 cluster in SEB-mediated inflammation. Furthermore, our results suggest that THC is a potent anti-inflammatory compound that may serve as a novel therapeutic to suppress SEB-induced pulmonary inflammation by modulating critical miRNA involved in SEB-induced toxicity and death.

Association of G1359A polymorphism of the cannabinoid receptor gene (CNR1) with macronutrient intakes in obese females

BACKGROUND

The endogenous cannabinoid system plays a role in metabolic aspects of body weight and feeding behaviour. A polymorphism (1359 G/A) (rs1049353) of the CB1 gene was reported as a common polymorphism in the Caucasian population. The present study aimed to investigate the association of the polymorphism (G1359A) of the CB1 receptor gene on macronutrient intake in females with obesity.

METHODS

A sample of 896 females was analysed. A bioimpedance measurement, a blood pressure measurement, a serial assessment of nutritional intake with 3 days of written food records, and a biochemical analysis were all performed. The genotype of the CNR1 receptor gene polymorphism (rs1049353) was studied.

RESULTS

Five hundred and sixteen patients (57.6%) had the genotype G1359G (non-A carriers) and 380 (42.4%) patients had G1359A (328 patients, 36.6%) or A1359A (52 patients, 5.8%) (A carriers). Triglycerides and high-density lipoprotein (HDL) cholesterol levels were higher in A non-A allele carriers than non-A allele carriers. The intakes of dietary cholesterol and saturated fat for the upper tertile (T3) compared to the baseline tertile were inversely associated with the CB1-R 1359 G/A polymorphism [odds ratio (OR) = 0.59; 95% confidence interval (CI) = 0.30-0.92 and OR = 0.66; 95% CI = 0.39-0.91, respectively]. These data were observed in the second tertile (T2) (OR = 0.61; 95% CI = 0.29-0.94 and OR = 0.58; 95% CI = 0.31-0.90, respectively).

CONCLUSIONS

The present study reports an association of the A allele with a better lipid profile (triglycerides and HDL cholesterol) than non-A allele carriers. In addition, this polymorphism is associated with a specific macronutrient intake, as well as with low cholesterol and fat saturated intakes.

Cannabis use by individuals with multiple sclerosis: effects on specific immune parameters

Cannabinoids affect immune responses in ways that may be beneficial for autoimmune diseases. We sought to determine whether chronic Cannabis use differentially modulates a select number of immune parameters in healthy controls and individuals with multiple sclerosis (MS cases). Subjects were enrolled and consented to a single blood draw, matched for age and BMI. We measured monocyte migration isolated from each subject, as well as plasma levels of endocannabinoids and cytokines. Cases met definition of MS by international diagnostic criteria. Monocyte cell migration measured in control subjects and individuals with MS was similarly inhibited by a set ratio of phytocannabinoids. The plasma levels of CCL2 and IL17 were reduced in non-naïve cannabis users irrespective of the cohorts. We detected a significant increase in the endocannabinoid arachidonoylethanolamine (AEA) in serum from individuals with MS compared to control subjects, and no significant difference in levels of other endocannabinoids and signaling lipids irrespective of Cannabis use. Chronic Cannabis use may affect the immune response to similar extent in individuals with MS and control subjects through the ability of phytocannabinoids to reduce both monocyte migration and cytokine levels in serum. From a panel of signaling lipids, only the levels of AEA are increased in individuals with MS, irrespective of Cannabis use or not. Our results suggest that both MS cases and controls respond similarly to chronic Cannabis use with respect to the immune parameters measured in this study.

Blunting of the HPA-axis underlies the lack of preventive efficacy of early post-stressor single-dose Delta-9-tetrahydrocannabinol (THC)

The therapeutic value of Delta-9-tetrahydrocannabinol (Δ9-THC) in the aftermath of trauma has recently raised interest. A prospective animal model for posttraumatic stress disorder was employed to assess the behavioral effects of a single dose of Δ9-THC administered intraperitoneally following exposure to psychogenic stress. Animals were exposed to predator scent stress and treated 1h later with Δ9-THC (1, 5 and 10mg/kg) or vehicle. The outcome measures included behavior in an elevated plus-maze and acoustic startle response 1, 6 and 24 h or 7 days after exposure and freezing behavior upon exposure to a trauma cue on day 8. Pre-set cut-off behavioral criteria classified exposed animals as those with "extreme," "minimal" or "intermediate" (partial) response. Circulating corticosterone levels were assessed over 2h after exposure with and without Δ9-THC. The behavioral effects of a CB1 antagonist (AM251) administered systemically 1h post exposure were evaluated. In the short term (1-6 h), 5 mg/kg of Δ9-THC effectively attenuated anxiety-like behaviors. In the longer-term (7 days), it showed no effect in attenuating PTSD-like behavioral stress responses, or freezing response to trauma cue. Δ9-THC significantly decreased corticosterone levels. In contrast, administration of AM251 (a CB1 antagonist/inverse agonist) 1 h post exposure attenuated long-term behavioral stress responses through activation of the HPA-axis. The demonstrated lack of preventive efficacy of early Δ9-THC treatment and reports of its anxiogenic effects in many individuals raises doubts not only regarding its potential clinical value, but also the advisability of clinical trials. The endocannabinoids exert complex effects on behavioral responses mediating glucocorticoid effects on memory of traumatic experiences.

Mid-ventricular variant takotsubo cardiomyopathy associated with Cannabinoid Hyperemesis Syndrome: a case report

A case of the mid-ventricular variant of takotsubo cardiomyopathy is reported, occurring in a patient with Cannabinoid Hyperemesis Syndrome (CHS), and presented with a review of the relevant literature. The patient is a 32-year-old woman who presented with epigastric pain, nausea and vomiting. Her EKG showed dynamic T-wave changes associated with a modest cardiac biomarker elevation. Ventricular wall motion abnormalities suggestive of the mid-ventricular variant of takotsubo cardiomyopathy were demonstrated by echocardiography, ventriculography and cardiac angiography, the latter showing normal coronary arteries. The patient was a previous marijuana user who had recently ingested marijuana after a period of abstinence. Severe epigastric pain, nausea and cyclic vomiting followed this. She had previously experienced similar gastrointestinal symptoms, relieved by compulsive hot water bathing, and resolving after marijuana cessation. Recent resumption of marijuana use was followed by a recurrence of these symptoms, a pattern characteristic of CHS. The association of cardiomyopathy with CHS has been described only once in the literature, and if this is a true relationship, its mechanism is not clearly defined. Animal models have suggested that endocannabinoid receptors are expressed in the myocardium, which could be a pathway for developing cardiac manifestations with cannabinoid use.

Cannabinoids for epilepsy

BACKGROUND

Marijuana appears to have anti-epileptic effects in animals. It is not currently known if it is effective in patients with epilepsy. Some states in the United States of America have explicitly approved its use for epilepsy.

OBJECTIVES

To assess the efficacy and safety of cannabinoids when used as monotherapy or add-on treatment for people with epilepsy.

SEARCH METHODS

We searched the Cochrane Epilepsy Group Specialized Register (9 September 2013), Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2013, Issue 8), MEDLINE (Ovid) (9 September 2013), ISI Web of Knowledge (9 September 2013), CINAHL (EBSCOhost) (9 September 2013), and ClinicalTrials.gov (9 September 2013). In addition, we included studies we personally knew about that were not found by the searches, as well as searched the references in the identified studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) whether blinded or not.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials for inclusion and extracted the data. The primary outcome investigated was seizure freedom at one year or more, or three times the longest interseizure interval. Secondary outcomes included responder rate at six months or more, objective quality of life data, and adverse events.

MAIN RESULTS

We found four randomized trial reports that included a total of 48 patients, each of which used cannabidiol as the treatment agent. One report was an abstract and another was a letter to the editor. Anti-epileptic drugs were continued in all studies. Details of randomisation were not included in any study report. There was no investigation of whether the control and treatment participant groups were the same or different. All the reports were low quality.The four reports only answered the secondary outcome about adverse effects. None of the patients in the treatment groups suffered adverse effects.

AUTHORS' CONCLUSIONS

No reliable conclusions can be drawn at present regarding the efficacy of cannabinoids as a treatment for epilepsy. The dose of 200 to 300 mg daily of cannabidiol was safely administered to small numbers of patients generally for short periods of time, and so the safety of long term cannabidiol treatment cannot be reliably assessed.

Novel Pharmacologic Approaches to Treating Cannabis Use Disorder

With large and increasing numbers of people using cannabis, the development of cannabis use disorder (CUD) is a growing public health concern. Despite the success of evidence-based psychosocial therapies, low rates of initial abstinence and high rates of relapse during and following treatment for CUD suggest a need for adjunct pharmacotherapies. Here we review the literature on medication development for the treatment of CUD, with a particular focus on studies published within the last three years (2010-2013). Studies in both the human laboratory and in the clinic have tested medications with a wide variety of mechanisms. In the laboratory, the following medication strategies have been shown to decrease cannabis withdrawal and self-administration following a period of abstinence (a model of relapse): the cannabinoid receptor agonist, nabilone, and the adrenergic agonist, lofexidine, alone and in combination with dronabinol (synthetic THC), supporting clinical testing of these medication strategies. Antidepressant, anxiolytic and antipsychotic drugs targeting monoamines (norepinephrine, dopamine, and serotonin) have generally failed to decrease withdrawal symptoms or laboratory measures of relapse. In terms of clinical trials, dronabinol and multiple antidepressants (fluoxetine, venlafaxine and buspirone) have failed to decrease cannabis use. Preliminary results from controlled clinical trials with gabapentin and N-acetylcysteine (NAC) support further research on these medication strategies. Data from open label and laboratory studies suggest lithium and oxytocin also warrant further testing. Overall, it is likely that different medications will be needed to target distinct aspects of problematic cannabis use: craving, ongoing use, withdrawal and relapse. Continued research is needed in preclinical, laboratory and clinical settings.

Dyskinesias in Parkinson's disease: views from positron emission tomography studies

Levodopa-induced dyskinesias (LIDs) and graft-induced dyskinesias (GIDs) are serious and common complications of Parkinson's disease (PD) management following chronic treatment with levodopa or intrastriatal transplantation with dopamine-rich foetal ventral mesencephalic tissue, respectively. Positron emission tomography (PET) molecular imaging provides a powerful in vivo tool that has been employed over the past 20 years for the elucidation of mechanisms underlying the development of LIDs and GIDs in PD patients. PET used together with radioligands tagging molecular targets has allowed the functional investigation of several systems in the brain including the dopaminergic, serotonergic, glutamatergic, opioid, endocannabinoid, noradrenergic and cholinergic systems. In this article the role of PET imaging in unveiling pathophysiological mechanisms underlying the development of LIDs and GIDs in PD patients is reviewed.