Search Results (947)

Endocannabinoids are lipid mediators consisting of esters, amides and ethers of long-chain polyunsaturated fatty acids. In this work, attention was focused on N-arachidonoyl tyrosine (NA-Tyr) and N-arachidonoyl dopamine (NADA), the amides of arachidonic acid with tyrosine and dopamine, respectively. NADA is an endogenous ligand of both type 1 cannabinoid receptors and type 1 vanilloid channel receptors. NADA is considered an endogenous compound with capsaicin-like activity and is distributed in several brain areas. The metabolic fate of endocannabinoids involves numerous enzymatic activities, which are only partially characterized. In particular, the biological activity of these biomolecules is terminated by enzymes with hydrolytic or oxygenase/oxidase activity. As part of this problem, we studied the oxidation of NADA and NA-Tyr mediated by mushroom tyrosinase. Our experimental data show that tyrosinase can oxidize both NADA and NA-Tyr. The oxidation of these biomolecules was also carried out in the presence of cysteine, allowing us to observe the formation of endocannabinoid/endovanilloid adducts with cysteine. These results were derived from chromatographic analyses and mass spectral experiments. During the tyrosinase-mediated oxidation in the presence of cysteine, it was possible to observe the production of a melanin-like pigment. The spectral characteristics of this pigment are consistent with those of pheomelanin, the pigment that contributes to the structure of neuromelanin. While mushroom tyrosinase serves here as a convenient biomimetic model to investigate the oxidative susceptibility of NADA and NA-Tyr, extrapolating these in vitro findings to mammalian physiology requires caution. Nevertheless, considering the neuronal distribution of these precursors and the documented, albeit debated, presence of tyrosinase-like activity in the central nervous system (CNS), these results offer a chemical rationale to further investigate whether similar oxidative pathways occur in vivo and potentially contribute to neurodegenerative mechanisms. Full article

Drug-resistant epilepsy is often associated with a neurodevelopmental disorder, focal cortical dysplasia (FCD). As demonstrated by numerous studies, defects in perisomatic inhibition may play a role in the formation of seizures. In our previous study, we observed an increase in parvalbumin-immunopositive perisomatic input. It has been observed that other perisomatic inhibitory cells expressing cannabinoid receptor type-1 (CB1R) and containing cholecystokinin (CCK) sprout in epileptic hippocampi. Therefore, we have investigated whether CB1R-immunopositive innervation has also changed in FCD. FCDIIB surgical samples were compared to controls with short post-mortem delay. The perisomatic input contacting principal cells was examined by NeuN-CB1R double immunostaining. Quantification in 3D was performed using a confocal fluorescence microscope. The results show that the CB1R-immunopositive synaptic input of principal cells is significantly larger in FCD cases. This condition may be an adaptive response to abnormal activity, or it may be a pre-existing pathology that is exacerbated by seizures. The reorganisation of the perisomatic inhibitory system has the potential to further increase the seizure probability in both cases. It should be noted that alterations in both PV- and CCK-CB1R-expressing basket cells may be implicated in seizure generation. Full article

The transcriptional regulation of the cannabinoid receptor 1 (CB1R) by promoter/enhancer elements and transcription factors is an area of cannabinoid research that has historically been understudied. To map the promoter region of the human CNR1 gene (the gene encoding CB1R), a 997-base-pair fragment from the sequence upstream of the CNR1 gene was cloned into a secreted luciferase reporter vector, and a series of deletion fragments were constructed. The transcriptional activity of these constructs was tested in human cell lines from three tissues: neuronal tissue (SHSY5Y), kidney tissue (HEK293T), and colonic epithelium (HCT116). Through this mapping, we have identified two key regulatory regions within the promoter. Increased levels of cAMP suppressed reporter expression from the full-length promoter fragment in all three cell lines, and in silico modeling predicts potential cAMP response elements (CRE) within one of the key regulatory sequences. Additionally, the minimal promoter region for CNR1 also appears to be in the second regulatory region identified, and in silico modeling predicts BRE and INR elements within this sequence. These findings begin to unravel the mechanisms by which CNR1 is transcriptionally regulated. Full article

Background: The endocannabinoid system (ECS) and the Kisspeptin system (KS) play crucial roles in the central and peripheral regulation of male reproduction. The KS comprises Kisspeptins, the cleavage product of the Kiss1 protein, and its receptor Kiss1R; it is a critical central regulatory factor of the Gonadotropin Releasing Hormone (GnRH), but its role in the testis in sustaining spermatogenesis is not fully understood. Similarly, in addition to the brain, the ECS is widely expressed in the testis, where it regulates spermatogenesis, steroidogenesis, and the production of high-quality gametes. Since the possible crosstalk between KS and ECS at the gonadal level is poorly understood, this study investigates the possible mutual modulation between ECS and KS in rat testis. Methods: Experiment 1: Testis pieces collected from adult rats were treated ex vivo for 1 h with the endocannabinoid anandamide (AEA, 10⁻⁸ M) ± SR141716A (10⁻⁷ M, a cannabinoid receptor (CB) 1 antagonist), or with SR141716A alone. Experiment 2: Testis pieces were treated for 4 h with decreasing doses of Kisspeptin-10 (Kp10, 10⁻⁶–10⁻⁹ M) ± Kp234 (a Kiss1R antagonist). Proteins extracted from the treated tissues were analyzed by Western blot for Kiss1R, Kiss1, CB1, CB2, AEA-hydrolyzing enzyme Fatty Acid Amide Hydrolase (FAAH), and AEA-biosynthetic enzyme N-acylphosphatidylethanolamine-specific phospholipase D (NAPE-PLD) proteins. Results: AEA treatment, via CB1, reduced Kiss1R protein in testis. Kp10 treatment increased the expression of CBs and NAPE-PLD at all doses and increased FAAH at 10⁻⁹ M dose only. Pre-incubation with Kp234 abolished Kp10 effects on CB1, NAPE-PLD, and FAAH, suggesting a direct Kp10-dependent modulation; on the other hand, pre-incubation with Kp234 did not abolish Kp10’s effects on CB2, suggesting an indirect action of Kp10 on CB2. Conclusions: Mutual modulation between ECS and KS exists in the testis: AEA, via CB1, suppresses Kisspeptin signaling, while Kisspeptin regulates the ECS through both Kiss1R-dependent and independent mechanisms. These local interactions identify new potential mechanisms in the intratesticular communications sustaining spermatogenesis via ECS and suggest that KS might be a new therapeutic target to rescue ECS impairment in male reproductive dysfunction. Full article

Recent evidence reveals that several psychotropic compounds exert significant biological effects on the skin through neurochemical and immunomodulatory pathways. Cannabinoids such as tetrahydrocannabinol (THC) show potent anti-inflammatory, antipruritic, and anti-aging properties when applied topically, and may hold therapeutic potential. Antidepressants, particularly fluoxetine (Prozac), have been shown to regulate the expression of pro-inflammatory cytokines in keratinocytes, suggesting benefits applied in allergic pathologies. Additionally, fluoxetine promotes wound healing and cell regeneration, indicating broader dermatological applications. Psychedelics, acting as serotonin receptor agonists (5-HTR), may influence cellular aging and immune modulation via the serotonergic system. Studies report that 5-HT receptor agonists can prevent UV-induced photocarcinogenesis, while psilocybin has been observed to reduce aging markers in human fibroblasts. Furthermore, recent data suggests that psilocin may alleviate acute itch involving the kynurenine pathway. These findings highlight the emerging relevance of psychoactive compounds in cutaneous biology, bridging neuropharmacology and dermatology toward novel therapeutic strategies. Full article

Cannabinoids are potential anticancer agents for the add-on treatment of malignant tumors. Here, the effects of the previously less-explored non-psychoactive phytocannabinoids cannabigerol (CBG) and cannabichromene (CBC) on survival, apoptosis, and mitochondrial function were assessed in A549 and H460 lung cancer cells. CBG and CBC triggered concentration-dependent cell death, autophagy, and mitochondrial apoptosis in both cell lines, with apoptosis indicated by Annexin V staining, activation of caspase-8, -9, and -3/7, loss of mitochondrial membrane potential, and elevated cytosolic levels of mitochondrial cytochrome c. CBG also upregulated ATF4, a stress-responsive transcription factor involved in autophagy and apoptotic signaling, and enhanced PARP cleavage. Both cannabinoids increased mitochondrial superoxide formation and reduced the mitochondrial oxygen consumption rate, with CBG additionally decreasing NDUFB8, a subunit of respiratory chain complex I. Pharmacological receptor modulation showed that CBG- and CBC-induced cell death occurred independently of CB₁, CB₂, TRPV1, TRPM8, and PPARγ, whereas CBG-mediated cell death relied on PPARα, which also contributed to its apoptotic effects. In summary, CBG and CBC induce apoptosis and cell death in A549 and H460 cells, with PPARα mediating the effects of CBG, highlighting its potential as a therapeutic target. Full article

Cannabinoids, including the psychoactive D9-tetrahydrocannabinol (THC) and the non-psychoactive cannabidiol (CBD), interact with receptors within the endocannabinoid system. The major receptors within this system are CNR1 (cannabinoid receptor 1) and CNR2 (cannabinoid receptor 2), which are both seven-transmembrane G-protein-coupled receptors. In this report, we used the Catalogue of Somatic Mutations in Cancers (COSMIC) to map and analyze mutations arising in CNR1 and CNR2. The goal was to determine if any trends or signatures could be identified. We identified several mutations in both CNR1 and CNR2. In silico 3D structure of proteins reveals that these mutations cluster on the intracellular regions of CNR1 and CNR2, and certain residues may be able to destabilize the interaction with the G-alpha protein due to their close proximity. mRNA expression showed that CNR1 and CNR2 are within normal expression levels in most cancer types except kidney, where there is a tendency towards over-expression. Neither CNR1 nor CNR2 is a driver gene, and our analysis shows that mutations in cancer cells are deactivating (e.g., loss of function). Full article

Background/Objectives: Dermatomyositis is an autoimmune disease with heterogeneous symptoms and many potential drivers. Nonpsychoactive cannabinoids have shown promise in treating some subtypes of DM; however, the reasons behind this were unclear. In this project, we tested the effects of CB2R activation on PBMCs from amyopathic and classic DM patients to determine its anti-inflammatory effects on pathways biologically relevant to DM. Methods: We determined the % CB2R positivity and intracellular cytokines in PBMCs from amyopathic DM and classic DM patients. CB2R positivity was determined by analyzing patient PBMCs via flow cytometry. PBMCs were stimulated by dsRNA for RIG1, dsDNA for cGAS, LPS for TLR4, and LPS/ATP for NLRP3, with and without CB2R pretreatment, and IFNβ, IFNγ, p65 NFkB, and pSTING levels were used as markers of pathway activation. The CB2R agonist JWH133 was used to pretreat PBMCs before stimulation. Results: Amyopathic DM PBMCS were found to be 101.3% more positive for CB2R compared to classic DM PBMCS (p < 0.05). In amyopathic DM PBMCs stimulated by LPS/ATP to target the NLRP3 inflammasome, CB2R activation resulted in a significant reduction in IFNβ MFI for MoDCs (p < 0.05) and Macs (p < 0.05), with a similar trend observed in cDCs relative to classic DM PBMCS. On the other hand, no difference in IFNβ response to CB2R activation was observed across all cell types investigated between classic and amyopathic DM PBMCs stimulated with LPS only to target TLR4. Conclusions: Amyopathic DM PBMCs were significantly more positive for CB2R and had better anti-inflammatory responses to CB2R activation for many inflammatory pathways implicated in DM. Full article

Background: Cocaine use disorder (CUD) remains a major global health concern, with no FDA-approved pharmacological treatments currently available. Cannabidiol (CBD), a non-psychoactive phytocannabinoid derived from Cannabis sativa L., has shown promising preclinical effects in disrupting the consolidation and retrieval of drug-associated memories, thereby attenuating relapse-like behaviors. Objectives: The present study evaluated the effects of a low-THC CBD-rich cannabis extract (NPCE) on the reinstatement and reconsolidation of cocaine-induced conditioned place preference (CPP) in male CD1 (ICR) mice, an approach not previously investigated. Methods: The extract was administered at a dose equivalent to 20 mg/kg of CBD. Treatment significantly attenuated both priming- and stress-induced reinstatement of cocaine-induced CPP. Reinstatement was triggered either by a cocaine priming injection or by acute stress exposure, whereas reconsolidation-like processes were assessed by administering the extract following memory reactivation sessions and subsequently evaluating the persistence of cocaine-associated preference over time. Results: NPCE showed a consistent result with disruption of reconsolidation-like processes of cocaine-associated memory, with effects persisting for at least two weeks. The extract alone did not induce conditioned preference or aversion. Conclusions: These findings suggest that NPCE modulates drug-associated memory processes involved in relapse-like behavior. However, the underlying mechanisms were not directly evaluated and remain to be elucidated. Further studies are warranted to include both sexes, evaluate effects across multiple behavioral paradigms, directly compare full-spectrum extracts with isolated cannabinoids, and incorporate receptor-specific approaches to clarify the mechanisms of action. Full article

Growth hormone-releasing hormone receptor 1a (GHS-R1a) is a key G protein-coupled receptor (GPCR) governing feeding and energy homeostasis. Accumulating evidence shows that GHS-R1a forms functional heterodimers with multiple metabolic-related GPCRs, including dopamine 2 receptor (D2R), melanocortin 3 receptor (MC3R), 5-hydroxytryptamine 2c receptor (5-HT2cR), orexin receptor 1 (OX1R) and cannabinoid receptor 1 (CB1R). These heterodimers undergo distinct signal transduction reprogramming, generating novel physiological effects that are not observed with individual receptors: for instance, GHS-R1a/D2R mediates an atypical calcium signaling pathway to regulate appetite, while GHS-R1a/5-HT2cR antagonizes ghrelin-induced orexigenic effects. Meanwhile, diverse detection techniques, including co-immunoprecipitation and fluorescence resonance energy transfer, have been developed to identify and validate GHS-R1a heterodimerization, laying a solid foundation for mechanistic research. This review systematically summarizes the molecular mechanisms of GHS-R1a heterodimer formation, the characteristic signal regulation patterns of different heterodimers, and their specific regulatory roles in feeding circuits. Furthermore, we discuss the existing research gaps in this field, such as the lack of in vivo detection methods for heterodimers and the unclear structural basis of dimerization. Finally, we highlight the potential of targeting specific GHS-R1a heterodimers as a novel therapeutic strategy for obesity and anorexia, providing new directions for future pharmaceutical development and clinical translation. Full article

Meningiomas are the most common intracranial tumours, yet the molecular programs underlying WHO grade 1 subtypes—particularly transitional diploid tumours—remain insufficiently defined, partly due to the scarcity of biologically faithful in vitro models. Here, we report the establishment of a long-term, genetically unmanipulated grade 1 meningioma cell line (H8T-MG) maintained under normoxic conditions in serum-containing, growth-factor-supplemented medium, together with a complementary long-term primary culture (H16T-MG), and provide an integrated descriptive and functional characterization of these models, combined with a subtype-restricted transcriptomic analysis of diploid transitional grade 1 tumours versus normal meninges. Both cultures preserved the dual meso-neuroectodermal identity characteristic of meningothelial cells, exhibiting stable adherent growth, preserved contact inhibition and a coherent immunocytochemical profile, expressing vimentin, α-SMA, nestin, connexin-43 and cannabinoid receptors—reported here for the first time in grade 1 meningioma cultures—highlighting cannabinoid-related pathways as potential targets for exploration. Transcriptomic analysis identified 51 differentially expressed genes, revealing a coherent inflammatory–metabolic programme characterised by downregulation of IL-17 and TNF signalling, cytokines and chemokines (IL6, CCL2, SELE, S100A8), together with reduced extracellular-matrix and cytoskeletal activity. In parallel, the enrichment of arachidonic acid metabolism, cytochrome-P450/xenobiotic pathways, retinol metabolism and oxidative/epoxygenase activity indicated a lipid/xenobiotic-oriented metabolic shift distinctive of this subtype. Protein–protein interaction analysis identified four hub genes—ASPN, SELE, ACKR1 and ABCB1—integrating ECM remodelling, endothelial–immune modulation and xenobiotic transport, reinforcing an immune-attenuated, metabolically adapted tumour landscape. Collectively, these findings provide the first integrated in vitro and transcriptomic characterisation of diploid transitional meningiomas, underscore the value of biologically stable models for early-stage meningioma research, and support the value of histological and ploidy stratification in grade 1 meningioma biology. Full article

Background/Objectives: Pathogenic variants in GNAO1, encoding the inhibitory G protein subunit Gαo, cause severe neurodevelopmental disorders that remain largely refractory to pharmacological treatments. Gαo transduces inhibitory signals downstream of multiple G protein-coupled receptors (GPCRs) involved in motor control. Here, we used gene-edited Caenorhabditis elegans models carrying goa-1 variants, the ortholog of GNAO1, to investigate GPCR contributions to Gαo-dependent locomotor phenotypes. Methods: We combined pharmacological screening of dopamine- and cannabinoid-targeting ligands in goa-1 mutants with structural analysis of ligand-binding pocket conservation and genetic perturbation of receptor function using RNAi and knockout approaches. Results: Pharmacological modulation of GPCR signaling produced non-linear and context-dependent effects. Compounds predicted to further increase excitability may instead promote phenotypic improvement, consistent with compensatory network rebalancing. Structural analyses revealed substantial divergence in ligand-binding pocket conservation for several GPCR-ligand pairs, suggesting that altered binding affinity and selectivity may also contribute to the observed phenotypic outcome. Pharmacological experiments performed in GPCR-depleted mutants allowed for the correlation of structural findings with functional effects for selected receptor-ligand pairs. Finally, genetic reduction in GPCRs coupled to stimulatory G proteins ameliorated hyperactive locomotion in goa-1 mutants, whereas reduction in GPCRs coupled to inhibitory G proteins is largely insufficient to induce or exacerbate locomotor defects. Conclusions: Our findings identify excessive excitatory GPCR input as a key modulator of motor dysfunction in the context of impaired Gαo signaling. They also show that structural conservation is a necessary but not sufficient condition to predict functional responses. Overall, this study establishes C. elegans as a suitable platform to dissect GPCR-mediated signaling and highlights the value of integrating pharmacological and genetic approaches to guide target selection in GNAO1-related disorders. Full article

Peripherally restricted (‘second-generation’) cannabinoid CB₁ receptor (CB₁R) antagonists have been suggested to have therapeutic potential in numerous diseases. However, their effects on the cardiovascular system require further research. The peripheral CB₁R antagonist AM6545 failed to modify the decrease in blood pressure (BP) elicited by inhibition of anandamide degradation in spontaneously hypertensive rats. The aims of the present study were to examine the effect of AM6545 on BP and its interaction with endocannabinoid-evoked effects in deoxycorticosterone acetate (DOCA)-salt rats. For this purpose, we applied methanandamide (MethAEA), a stable analogue of anandamide, and URB597, an inhibitor of its degradation, in urethane-anesthetized animals. AM6545 did not affect BP by itself. MethAEA elicited a biphasic effect (a rise in BP, followed by its fall); both phases were antagonized by AM6545. URB597 induced a monophasic hypotensive effect, which was abolished by AM6545 in DOCA-salt rats but further enhanced in control animals. AM6545 also unmasked an additional increase in BP after URB597 in both groups of rats. In conclusion, AM6545 modifies the cardiovascular effects of endocannabinoids in hypertension in a model-dependent manner. The cardiovascular effects of CB₁R antagonists should be carefully evaluated when assessing their potential therapeutic significance, as they may unmask an increase in BP. Full article

Obesity resulting from melanocortin-4 receptor (MC4R) dysfunction is characterized by combined metabolic dysregulation and maladaptive reward-related behaviors that limit the durability of existing therapies. The endocannabinoid system is a central regulator of appetite, lipid metabolism, and reward processing; however, first-generation cannabinoid receptor 1 (CB1) antagonists were limited by adverse neuropsychiatric effects. SKNY-1 is an orally active tetrahydrocannabivarin (THCV) analog designed to engage pathway-biased CB1 signaling, modulate cannabinoid receptor 2 (CB2), and selectively inhibit monoamine oxidase B (MAO-B), with the objective of addressing both metabolic and behavioral components of obesity while minimizing central nervous system liability through biased CB1 signaling, CB2 modulation, and potential complementary MAO-B inhibition. Here, we integrated in vitro pharmacological profiling of SKNY-1 with in vivo evaluation in an adult mc4r(G894C) zebrafish model exhibiting obesity-associated metabolic and reward-related phenotypes. In vitro, SKNY-1 displayed low-potency modulation of CB1 cyclic AMP signaling (EC₅₀ ~30 µM) but more potent antagonism of the CB1 β-arrestin pathway (IC₅₀ ~6 µM), consistent with differential CB1 pathway modulation. SKNY-1 acted as a CB2 partial agonist (EC₅₀ ~0.1 µM), with antagonist activity emerging at higher concentrations, and selectively inhibited MAO-B at low affinity with no activity against MAO-A. In vivo, mc4r(G894C) zebrafish mutants exhibited dyslipidemia, hepatic triglyceride accumulation, altered appetite-regulatory gene expression, increased metabolic rate, and enhanced compulsive high-calorie feeding and nicotine-seeking behaviors. Oral administration of SKNY-1 for six days produced dose-dependent effects. Both doses normalized total cholesterol and low-density lipoprotein levels and reduced hepatic triglycerides toward wild-type values without affecting circulating triglycerides. The higher dose (200 ng per fish per day) induced significant body weight reduction while preserving body density and attenuated reward-associated feeding and nicotine-seeking behaviors. The lower dose (20 ng per fish per day) more effectively normalized the leptin a-to-ghrelin expression ratio. Collectively, these findings demonstrate that SKNY-1 engages integrated endocannabinoid and potential dopaminergic mechanisms to improve metabolic parameters and attenuate maladaptive reward-related behaviors in an MC4R-deficient vertebrate model, supporting its further translational investigation for obesity complicated by compulsive eating and substance-seeking behaviors. Full article

Concurrent alcohol and cannabis use (“crossfading”) is increasingly prevalent, especially among adolescents, yet its toxicological impact on pulmonary innate immunity remains largely unexplored. Alveolar macrophages (AMs) orchestrate inflammatory responses in the lung, and dysregulated macrophage polarization is a hallmark of alcohol-associated lung disease. Although alcohol and cannabinoids individually modulate immune function, the mechanisms by which their co-exposure alters macrophage activation and inflammatory signaling in the lung are largely unknown. AMs are highly sensitive to xenobiotic exposure and play a central role in regulating inflammatory and cytotoxic responses. In this study, we investigated how acute ethanol exposure, synthetic cannabinoid exposure, and their combined exposure affect macrophage viability, polarization, and the release of inflammatory mediators via cannabinoid receptor (CB1R/CB2R)-dependent pathways. Human THP-1-derived macrophages and KG-1 macrophage-like cells were exposed to ethanol, the CB1/CB2 agonist WIN 55,212-2, or both, with selective pharmacological antagonism of CB1R and CB2R. Ethanol exposure activated and polarized macrophages toward a pro-inflammatory M1 phenotype, accompanied by increased secretion of pro-inflammatory cytokines MCP-1, TGF-α, IFN-β, IL-6, and TNF-α. In contrast, WIN 55,212-2 promoted anti-inflammatory M2 polarization and increased IL-10 and IL-4 production. Notably, co-exposure to ethanol and WIN produced an antagonistic immunomodulatory response, characterized by the suppression of ethanol-induced M1 polarization and attenuation of pro-inflammatory cytokine release. Mechanistically, pharmacological CB1R blockade reduced ethanol-induced M1 polarization and cytokine secretion, whereas CB2R blockade exacerbated these effects, underscoring divergent roles for cannabinoid receptors in regulating pulmonary macrophage responses. This study provides novel findings demonstrating the mechanism by which alcohol–cannabinoid co-use reshapes macrophage immune phenotypes and identifies the endocannabinoid system as a potential therapeutic target for alcohol-related inflammatory lung disease. Full article