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Sample records for cb1 receptor antagonist

  1. A cannabinoid CB(1) receptor antagonist ameliorates impairment of recognition memory on withdrawal from MDMA (Ecstasy).

    Science.gov (United States)

    Nawata, Yoko; Hiranita, Takato; Yamamoto, Tsuneyuki

    2010-01-01

    (+/-)-3,4-Methylenedioxymethamphetamine (MDMA, 'Ecstasy') abusers have persistent neuropsychiatric deficits including memory impairments after the cessation of abuse. On the other hand, cannabinoid CB(1) receptors have been implicated in learning/memory, and are highly expressed in the hippocampus, a region of the brain believed to have an important function in certain forms of learning and memory. In this study, we clarified the mechanism underlying the cognitive impairment that develops during MDMA withdrawal from the standpoint of the cannabinoid CB(1) receptors. Mice were administered MDMA (10 mg/kg, i.p.) once a day for 7 days. On the 7th day of withdrawal, a novel object recognition task was performed and the amount of cannabinoid CB(1) receptor protein was measured with western blotting. Recognition performance was impaired on the 7th day of withdrawal. This impairment was blocked by AM251, a cannabinoid CB(1) receptor antagonist, administered 30 min before the training trial or co-administered with MDMA. At this time, the level of cannabinoid CB(1) receptor protein increased significantly in the hippocampus but not the prefrontal cortex or striatum. This increase of CB(1) receptor protein in the hippocampus was also blocked by the co-administration of AM251. Furthermore, CB(1) receptor knockout mice showed no impairment of recognition performance on the withdrawal from MDMA. The impairment of recognition memory during withdrawal from MDMA may result from the activation of cannabinoid CB(1) receptors in the hippocampus.

  2. Pyrazole antagonists of the CB1 receptor with reduced brain penetration.

    Science.gov (United States)

    Fulp, Alan; Zhang, Yanan; Bortoff, Katherine; Seltzman, Herbert; Snyder, Rodney; Wiethe, Robert; Amato, George; Maitra, Rangan

    2016-03-01

    Type 1 cannabinoid receptor (CB1) antagonists might be useful for treating obesity, liver disease, metabolic syndrome, and dyslipidemias. Unfortunately, inhibition of CB1 in the central nervous system (CNS) produces adverse effects, including depression, anxiety and suicidal ideation in some patients, which led to withdrawal of the pyrazole inverse agonist rimonabant (SR141716A) from European markets. Efforts are underway to produce peripherally selective CB1 antagonists to circumvent CNS-associated adverse effects. In this study, novel analogs of rimonabant (1) were explored in which the 1-aminopiperidine group was switched to a 4-aminopiperidine, attached at the 4-amino position (5). The piperidine nitrogen was functionalized with carbamates, amides, and sulfonamides, providing compounds that are potent inverse agonists of hCB1 with good selectivity for hCB1 over hCB2. Select compounds were further studied using in vitro models of brain penetration, oral absorption and metabolic stability. Several compounds were identified with predicted minimal brain penetration and good metabolic stability. In vivo pharmacokinetic testing revealed that inverse agonist 8c is orally bioavailable and has vastly reduced brain penetration compared to rimonabant.

  3. Attenuation of morphine antinociceptive tolerance by cannabinoid CB1 and CB2 receptor antagonists.

    Science.gov (United States)

    Altun, Ahmet; Yildirim, Kemal; Ozdemir, Ercan; Bagcivan, Ihsan; Gursoy, Sinan; Durmus, Nedim

    2015-09-01

    Cannabinoid CB1 and CB2 receptor antagonists may be useful for their potential to increase or prolong opioid analgesia while attenuating the development of opioid tolerance. The aim of this study was to investigate the effects of AM251 (a selective CB1 antagonist) and JTE907 (a selective CB2 antagonist) on morphine analgesia and tolerance in rats. Adult male Wistar albino rats weighing 205-225 g were used in these experiments. To constitute morphine tolerance, we used a 3 day cumulative dosing regimen. After the last dose of morphine was injected on day 4, morphine tolerance was evaluated by analgesia tests. The analgesic effects of morphine (5 mg/kg), ACEA (a CB1 receptor agonist, 5 mg/kg), JWH-015 (a CB2 receptor agonist, 5 mg/kg), AM251 (1 mg/kg) and JTE907 (5 mg/kg) were considered at 30-min intervals (0, 30, 60, 90, and 120 min) by tail-flick and hot-plate analgesia tests. Our findings indicate that ACEA and JWH907 significantly increased morphine analgesia and morphine antinociceptive tolerance in the analgesia tests. In contrast, the data suggested that AM251 and JTE907 significantly attenuated the expression of morphine tolerance. In conclusion, we observed that co-injection of AM251 and JTE907 with morphine attenuated expression of tolerance to morphine analgesic effects and decreased the morphine analgesia.

  4. Cannabinoid CB1 receptor antagonist rimonabant disrupts nicotine reward-associated memory in rats.

    Science.gov (United States)

    Fang, Qin; Li, Fang-Qiong; Li, Yan-Qin; Xue, Yan-Xue; He, Ying-Ying; Liu, Jian-Feng; Lu, Lin; Wang, Ji-Shi

    2011-10-01

    Exposure to cues previously associated with drug intake leads to relapse by activating previously acquired memories. Based on previous findings, in which cannabinoid CB(1) receptors were found to be critically involved in specific aspects of learning and memory, we investigated the role of CB(1) receptors in nicotine reward memory using a rat conditioned place preference (CPP) model. In Experiment 1, rats were trained for CPP with alternating injections of nicotine (0.5mg/kg, s.c.) and saline to acquire the nicotine-conditioned memory. To examine the effects of rimonabant on the reconsolidation of nicotine reward memory, rats were administered rimonabant (0, 0.3, and 3.0mg/kg, i.p.) immediately after reexposure to the drug-paired context. In Experiment 2, rats were trained for CPP similarly to Experiment 1. To examine the effects of rimonabant on the reinstatement of nicotine reward memory, rimonabant (0, 0.3, and 3.0mg/kg, i.p.) was administered before the test of nicotine-induced CPP reinstatement. In Experiment 3, to evaluate whether rimonabant itself produces a reward memory, rats were trained for CPP with alternating injections of different doses of rimonabant (0, 0.3, and 3.0mg/kg) and saline. Rimonabant at a dose of 3.0mg/kg significantly disrupted the reconsolidation of nicotine memory and significantly blocked the reinstatement of nicotine-induced CPP. However, rimonabant itself did not produce CPP. These findings provide clear evidence that CB(1) receptors play a role in nicotine reward memory, suggesting that CB(1) receptor antagonists may be a potential target for managing nicotine addiction.

  5. Novel Method for Synthesis of Diarylpyrazole Derivatives as Cannabinoid CB1 Receptor Antagonists

    Institute of Scientific and Technical Information of China (English)

    WU Ying-qiu; ZHENG Guo-jun; WANG Ya-ping; WANG Xiang-jing; XIANG Wen-sheng

    2011-01-01

    A novel and efficient method was developed for the synthesis of diarylpyrazole derivatives as cannabinoid CB1 receptor antagonist via four step reactions. The key step was the synthesis of a diarylpyrazole skeleton, which involved initial condensation of the sodium salt of compound 12 with diazonium compounds, and further cyclization by heating at reflux in acetic acid. Eight diarylpyrazole derivatives and nine new synthesized compounds were cha racterized by 1H NMRy IR, MS, and elemental analysis. The reaction conditions were mild and the overall yields of the target compounds ranged from 26% to 44%.

  6. Evaluation of the abuse potential of AM281, a new synthetic cannabinoid CB1 receptor antagonist.

    Science.gov (United States)

    Botanas, Chrislean Jun; de la Peña, June Bryan; Dela Pena, Irene Joy; Tampus, Reinholdgher; Kim, Hee Jin; Yoon, Seong Shoon; Seo, Joung-Wook; Jeong, Eun Ju; Cheong, Jae Hoon

    2015-11-01

    AM281 (1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-4-morpholinyl-1H-pyrazole-3-carboxamide) is a new synthetic cannabinoid CB1 receptor antagonist. Similar to other cannabinoid antagonists, AM281 has been suggested to have therapeutic indications. However, recent reports have suggested that cannabinoid CB1 receptor antagonists may share similar behavioral effects with other drugs of abuse such as cocaine and amphetamine. These reports cast doubts on the safety profile of AM281. Thus, in the present study we evaluated the abuse potential (rewarding and reinforcing effects) of AM281 through two of the most widely used animal models for assessing the abuse potential of drugs: the conditioned place preference (CPP) and self-administration (SA) tests. Experiments were performed in Sprague-Dawley rats in various dosages [CPP (0.1, 0.5 or 2.5mg/kg), SA (0.005, 0.025 or 0.1mg/kg/infusion)]. We also delved into the consequences of repeated drug exposure on the subsequent response to the drug. Thus, parallel experiments were carried out in rats pretreated with AM281 for 7 or 14 days. Our findings indicated that AM281, at any dose, did not induce CPP and SA in drug-naïve rats. Interestingly, significant CPP (0.5mg/kg of AM281), but not SA, was observed in 14 days pretreated rats. These observations suggest that AM281 per se has no or minimal rewarding and reinforcing properties, but alterations in neuronal functions and behavior due to repeated AM281 exposure may contribute in part to the abuse potential of this drug. In view of this finding, we advocate the careful use, monitoring, and dispensation of AM281.

  7. Modulatory effects by CB1 receptors on rat spinal locomotor networks after sustained application of agonists or antagonists.

    Science.gov (United States)

    Veeraraghavan, P; Nistri, A

    2015-09-10

    Sustained administration of cannabinoid agonists acting on neuronal CB1 receptors (CB1Rs) are proposed for treating spasticity and chronic pain. The impact of CB1Rs on mammalian locomotor networks remains, however, incompletely understood. To clarify how CB1Rs may control synaptic activity and locomotor network function, we used the rat spinal cord in vitro which is an advantageous model to investigate locomotor circuit mechanisms produced by the local central pattern generator. Neither the CB1 agonist anandamide (AEA) nor the CB1R antagonist AM-251 evoked early (3-24h largely impaired locomotor network activity induced by DR stimuli or neurochemicals, and depressed disinhibited bursting without changing reflex amplitude or inducing neurotoxicity even if CB1R immunoreactivity was lowered in the central region. Since CB1R activation usually inhibits cyclic adenosine monophosphate (cAMP) synthesis, we investigated how a 24-h application of AEA or AM-251 affected basal or forskolin-stimulated cAMP levels. While AEA decreased them in an AM-251-sensitive manner, AM-251 per se did not change resting or stimulated cAMP. Our data suggest that CB1Rs may control the circuit gateway regulating the inflow of sensory afferent inputs into the locomotor circuits, indicating a potential site of action for restricting peripheral signals disruptive for locomotor activity.

  8. Novel selective cannabinoid CB1 receptor antagonist MJ08 with potent in vivo bioactivity and inverse agonistic effects

    Institute of Scientific and Technical Information of China (English)

    Wei CHEN; Cheng XU; Hong-ying LIU; Long LONG; Wei ZHANG; Zhi-bing ZHENG; Yun-de XIE; Li-li WANG; Song LI

    2011-01-01

    To characterize the biological profiles of M J08,a novel selective CB1 receptor antagonist.Methods:Radioligand binding assays were performed using rat brain and spleen membrane preparations.CB1 and CB2 receptor redistribution and intracellular Ca2+ ([Ca2+]1) assays were performed with IN CELL Analyzer.Inverse agonism was studied using intracellular cAMP assays,and in guinea-pig ileum and mouse vas deferens smooth muscle preparations.In vivo pharmacologic profile was assessed in diet-induced obesity (DIO) mice.Results:In radioligand binding assay,M J08 selectively antagonized CB1 receptor (IC50=99.9 nmol/L).In EGFP-CB1_U20S cells,its IC50 value against CB1 receptor activation was 30.23 nmol/L (SR141716A:32.16 nmol/L).WIN 55,212-2 (1 μmol/L) increased [Ca2+]1 in the primary cultured hippocampal neuronal cells and decreased cAMP accumulation in CHO-hCB1 cells.M J08 (10 nmol/L-1O μmol/L)blocked both the WIN 55,212-2-induced effects.Furthermore,M J08 reversed the inhibition of electrically evoked twitches of mouse vas deferens by WIN 55,212-2 (pA2=10.29±1.05).M J08 and SR141716A both showed an inverse agonism activity by markedly promoting the contraction force and frequency of guinea pig ileum muscle.M J08 significantly increased the cAMP level in CHO-hCB1 cells with an EC50 value of 78.6 nmol/L,which was lower than the EC50 value for SR141716A (159.2 nmol/L).Besides the more potent pharmacological effects of cannabinoid CB1 receptor antagonism in DIO mice,such as reducing food intake,decreasing body weight,and ameliorating dyslipidemia,M J08 (10 mg/kg) unexpectedly raised the fasted blood glucose in vivo.Conclusion:M J08 is a novel,potent and selective CB1 receptor antagonist/inverse agonist with potent bioactive responses in vitro and in vivo that may be useful for disclosure the versatile nature of CB1 receptors.

  9. The effects of cannabinoid CB1, CB2 and vanilloid TRPV1 receptor antagonists on cocaine addictive behavior in rats.

    Science.gov (United States)

    Adamczyk, Przemysław; Miszkiel, Joanna; McCreary, Andrew C; Filip, Małgorzata; Papp, Mariusz; Przegaliński, Edmund

    2012-03-20

    There is evidence that indicates that tonic activation of cannabinoid CB1 receptors plays a role in extinction/reinstatement of cocaine seeking-behavior but is not involved in the maintenance of cocaine self-administration. To further explore the importance of other endocannabinoid-related receptors in an animal model of cocaine addiction, the present paper examines cannabinoid CB2 receptor antagonist N-((1S)-endo-1,3,3-trimethylbicyclo(2.2.1)heptan-2-yl)-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide (SR144528) and the transient receptor potential vanilloid type-1 (TRPV1) receptor antagonist N-(3-methoxyphenyl)-4-chlorocinnamide (SB366791) on intravenous (i.v.) cocaine self-administration and extinction/reinstatement of cocaine-seeking behavior in rats. For comparison and reference purposes, the effect of the cannabinoid CB1 receptor antagonist N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251) was also examined. Moreover, for comparison effects of those drugs on operant lever responding for artificial (cocaine) vs. natural (food) reward, food self-administration was also evaluated. Our findings show that AM251 (1-3mg/kg), SR144528 (0.1-1mg/kg) and SB366791 (0.3-1mg/kg) did not affect cocaine self-administration. However, AM251 (0.1-1mg/kg), SR144528 (0.1-1mg/kg) and SB366791 (0.1-1mg/kg) decreased cocaine-induced reinstatement of cocaine-seeking behavior, and AM251 (0.3-1mg/kg) decreased cue-induced reinstatement. Moreover, AM251 (3mg/kg), SR144528 (0.1-1mg/kg) and SB366791 (0.1-1mg/kg) slightly decreased food self-administration behavior, but only AM251 (3mg/kg) reduced food reward. In conclusion, our results indicate for the first time, that tonic activation of CB2 or TRPV1 receptors is involved in cocaine-induced reinstatement of cocaine-seeking behavior, but their activity is not necessary for the rewarding effect of this psychostimulant. In contrast to CB1 receptors, neither CB2 nor

  10. CB1 and CB2 cannabinoid receptor antagonists prevent minocycline-induced neuroprotection following traumatic brain injury in mice.

    Science.gov (United States)

    Lopez-Rodriguez, Ana Belen; Siopi, Eleni; Finn, David P; Marchand-Leroux, Catherine; Garcia-Segura, Luis M; Jafarian-Tehrani, Mehrnaz; Viveros, Maria-Paz

    2015-01-01

    Traumatic brain injury (TBI) and its consequences represent one of the leading causes of death in young adults. This lesion mediates glial activation and the release of harmful molecules and causes brain edema, axonal injury, and functional impairment. Since glial activation plays a key role in the development of this damage, it seems that controlling it could be beneficial and could lead to neuroprotective effects. Recent studies show that minocycline suppresses microglial activation, reduces the lesion volume, and decreases TBI-induced locomotor hyperactivity up to 3 months. The endocannabinoid system (ECS) plays an important role in reparative mechanisms and inflammation under pathological situations by controlling some mechanisms that are shared with minocycline pathways. We hypothesized that the ECS could be involved in the neuroprotective effects of minocycline. To address this hypothesis, we used a murine TBI model in combination with selective CB1 and CB2 receptor antagonists (AM251 and AM630, respectively). The results provided the first evidence for the involvement of ECS in the neuroprotective action of minocycline on brain edema, neurological impairment, diffuse axonal injury, and microglial activation, since all these effects were prevented by the CB1 and CB2 receptor antagonists.

  11. Falcarinol is a covalent cannabinoid CB1 receptor antagonist and induces pro-allergic effects in skin.

    Science.gov (United States)

    Leonti, Marco; Casu, Laura; Raduner, Stefan; Cottiglia, Filippo; Floris, Costantino; Altmann, Karl-Heinz; Gertsch, Jürg

    2010-06-15

    The skin irritant polyyne falcarinol (panaxynol, carotatoxin) is found in carrots, parsley, celery, and in the medicinal plant Panax ginseng. In our ongoing search for new cannabinoid (CB) receptor ligands we have isolated falcarinol from the endemic Sardinian plant Seseli praecox. We show that falcarinol exhibits binding affinity to both human CB receptors but selectively alkylates the anandamide binding site in the CB(1) receptor (K(i)=594nM), acting as covalent inverse agonist in CB(1) receptor-transfected CHO cells. Given the inherent instability of purified falcarinol we repeatedly isolated this compound for biological characterization and one new polyyne was characterized. In human HaCaT keratinocytes falcarinol increased the expression of the pro-allergic chemokines IL-8 and CCL2/MCP-1 in a CB(1) receptor-dependent manner. Moreover, falcarinol inhibited the effects of anandamide on TNF-alpha stimulated keratinocytes. In vivo, falcarinol strongly aggravated histamine-induced oedema reactions in skin prick tests. Both effects were also obtained with the CB(1) receptor inverse agonist rimonabant, thus indicating the potential role of the CB(1) receptor in skin immunopharmacology. Our data suggest anti-allergic effects of anandamide and that falcarinol-associated dermatitis is due to antagonism of the CB(1) receptor in keratinocytes, leading to increased chemokine expression and aggravation of histamine action.

  12. Effects of the novel cannabinoid CB1 receptor antagonist PF 514273 on the acquisition and expression of ethanol conditioned place preference.

    Science.gov (United States)

    Pina, Melanie M; Cunningham, Christopher L

    2014-08-01

    The centrally expressed cannabinoid receptor (CB1) has been considered a potential therapeutic target in treating alcoholism. Though CB1 receptors have been shown to modulate primary and conditioned ethanol reward, much of this research employed animal models that require ethanol ingestion or oral routes of administration. This is problematic considering CB1 antagonist drugs have high anorectic liability and have been used clinically in the treatment of obesity. Therefore, the present study examined CB1 antagonism in DBA/2J mice using an unbiased ethanol-induced conditioned place preference (CPP) procedure, a paradigm that does not require ethanol ingestion. To evaluate the role of CB1 receptors in primary ethanol reward, the highly potent and selective novel CB1 antagonist 2-(2-chlorophenyl)-3-(4-chlorophenyl)-7-(2,2-difluoropropyl)-6,7-dihydro-2H-pyrazolo[3,4-f][1,4]oxazepin-8(5H)-one (PF 514273) was administered 30 min before place preference conditioning with a fixed dose of ethanol (acquisition). To evaluate the role of CB1 receptors in ethanol-conditioned reward, PF 514273 was administered 30 min before place preference testing (expression). Although PF 514273 reduced ethanol-stimulated and basal locomotor activity, it did not perturb the acquisition or expression of ethanol-induced CPP. Results from the present study appear inconsistent with other studies that have demonstrated a role for CB1 antagonism in ethanol reward using oral administration paradigms. Our findings suggest that CB1 antagonism may have greater involvement in consummatory behavior than ethanol reward.

  13. Systemic or intra-amygdala infusion of an endocannabinoid CB1 receptor antagonist AM251 blocked propofol-induced anterograde amnesia.

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    Ren, Y; Wang, J; Xu, P B; Xu, Y J; Miao, C H

    2015-01-01

    Propofol is well-known for its anterograde amnesic actions. However, a recent experiment showed that propofol can also produce retrograde memory enhancement effects via an interaction with the endocannabinoid CB1 system. Therefore, the authors hypothesized that the regulating effect of propofol on the endocannabinoid CB1 system might also decrease the anterograde amnesic effect of propofol under some conditions, which might be a risk factor for intraoperative awareness. Since, the basolateral amygdala (BLA) has been confirmed to mediate propofol-induced anterograde amnesia and the BLA contains a high concentration of CB1 receptors, the authors investigated whether and how the endocannabinoid system, particularly the CB1 receptor within BLA, influences propofol-induced anterograde amnesia. Male Sprague-Dawley rats trained with inhibitory avoidance (IA) were systematically pre-trained using a memory-impairing dose of propofol (25 mg/kg). Before propofol administration, rats received an intraperitoneal injection of a CB1 receptor antagonist AM251 (1 mg/kg or 2 mg/kg) or a bilateral intra-BLA injection of AM251 (0.6 ng or 6 ng per 0.5 μl). Twenty-four hours after IA training, the IA retention latency was tested. It was found that systemic or intra-BLA injection of a non-regulating dose of AM251 (2 mg/kg or 6 ng per 0.5 μl, respectively) blocked the memory-impairing effect of propofol. These results indicate that the anterograde amnesic effect of propofol is mediated, in part, by activation of the CB1 cannabinoid receptors in the BLA.

  14. Anti-obesity efficacy of LH-21, a cannabinoid CB1 receptor antagonist with poor brain penetration, in diet-induced obese rats

    Science.gov (United States)

    Alonso, Mónica; Serrano, Antonia; Vida, Margarita; Crespillo, Ana; Hernandez-Folgado, Laura; Jagerovic, Nadine; Goya, Pilar; Reyes-Cabello, Carmen; Perez-Valero, Vidal; Decara, Juan; Macías-González, Manuel; Bermúdez-Silva, Francisco Javier; Suárez, Juan; Rodríguez de Fonseca, Fernando; Pavón, Francisco Javier

    2012-01-01

    BACKGROUND AND PURPOSE Peripheral blockade of cannabinoid CB1 receptors has been proposed as a safe and effective therapy against obesity, putatively devoid of the adverse psychiatric side effects of centrally acting CB1 receptor antagonists. In this study we analysed the effects of LH-21, a peripherally acting neutral cannabinoid receptor antagonist with poor brain penetration, in an animal model of diet-induced obesity. EXPERIMENTAL APPROACH To induce obesity, male Wistar rats were fed a high-fat diet (HFD; 60 kcal% fat) whereas controls received a standard diet (SD; 10 kcal% fat). Following 10 weeks of feeding, animals received a daily i.p. injection of vehicle or 3 mg·kg−1 LH-21 for 10 days. Plasma and liver samples were used for biochemical analyses whereas visceral fat-pad samples were analysed for lipid metabolism gene expression using real-time RT-PCR. In addition, the potential of LH-21 to interact with hepatic cytochrome P450 isoforms and cardiac human Ether-à-go-go Related Gene (hERG) channels was evaluated. KEY RESULTS LH-21 reduced feeding and body weight gain in HFD-fed animals compared with the control group fed SD. In adipose tissue, this effect was associated with decreased gene expression of: (i) leptin; (ii) lipogenic enzymes, including SCD-1; (iii) CB1 receptors; and (iv) both PPARα and PPARγ. Although there were no significant differences in plasma parameters between HFD- and SD-fed rats, LH-21 did not seem to induce hepatic, cardiac or renal toxicity. CONCLUSIONS AND IMPLICATIONS These results support the hypothesis that treatment with the peripherally neutral acting CB1 receptor antagonist, LH-21, may promote weight loss through modulation of visceral adipose tissue. PMID:21951309

  15. Crystal Structure of the Human Cannabinoid Receptor CB1.

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    Hua, Tian; Vemuri, Kiran; Pu, Mengchen; Qu, Lu; Han, Gye Won; Wu, Yiran; Zhao, Suwen; Shui, Wenqing; Li, Shanshan; Korde, Anisha; Laprairie, Robert B; Stahl, Edward L; Ho, Jo-Hao; Zvonok, Nikolai; Zhou, Han; Kufareva, Irina; Wu, Beili; Zhao, Qiang; Hanson, Michael A; Bohn, Laura M; Makriyannis, Alexandros; Stevens, Raymond C; Liu, Zhi-Jie

    2016-10-20

    Cannabinoid receptor 1 (CB1) is the principal target of Δ(9)-tetrahydrocannabinol (THC), a psychoactive chemical from Cannabis sativa with a wide range of therapeutic applications and a long history of recreational use. CB1 is activated by endocannabinoids and is a promising therapeutic target for pain management, inflammation, obesity, and substance abuse disorders. Here, we present the 2.8 Å crystal structure of human CB1 in complex with AM6538, a stabilizing antagonist, synthesized and characterized for this structural study. The structure of the CB1-AM6538 complex reveals key features of the receptor and critical interactions for antagonist binding. In combination with functional studies and molecular modeling, the structure provides insight into the binding mode of naturally occurring CB1 ligands, such as THC, and synthetic cannabinoids. This enhances our understanding of the molecular basis for the physiological functions of CB1 and provides new opportunities for the design of next-generation CB1-targeting pharmaceuticals.

  16. 外周型Ⅰ型大麻素受体选择性拮抗剂的研究进展%Peripherally restricted CB1 receptor antagonist:research advances

    Institute of Scientific and Technical Information of China (English)

    税凤春; 陈伟; 徐静华; 王莉莉

    2014-01-01

    Ⅰ型大麻素受体(cannabinoid 1 receptor,CB1R)是肥胖症治疗药物研发的最重要靶标之一,然而以利莫那班为代表的 CB1R 拮抗剂因中枢作用产生的副作用限制了其临床应用。不透过血脑屏障的外周型 CB1R 选择性拮抗剂在保留第1代CB1R 拮抗剂减肥效应的同时,避免了其中枢相关的副作用,成为当前 CB1R 拮抗剂类新型减肥药物研发的方向。本文综述了外周型 CB1R 选择性拮抗剂的研究进展。%Cannabinoid 1 receptor (CB1R) is one of most important targets for the treatment of obesity. However, the clinical application of CB1R antagonist rimonabant is restricted because of the central nervous system-related unwanted liabilities. Peripherally restricted CB1R antagonist with limited blood-brain-barrier penetration may maintain the antiobesity efficacy of rimonabant without unwanted side effects. This strategy has become the new hot spot for the development of antiobesity drugs. In this paper, we review the recent progress in peripherally restricted CB1 receptor antagonist .

  17. Loss of cannabinoid receptor CB1 induces preterm birth.

    Directory of Open Access Journals (Sweden)

    Haibin Wang

    Full Text Available BACKGROUND: Preterm birth accounting approximate 10% of pregnancies in women is a tremendous social, clinical and economic burden. However, its underlying causes remain largely unknown. Emerging evidence suggests that endocannabinoid signaling via cannabinoid receptor CB1 play critical roles in multiple early pregnancy events in both animals and humans. Since our previous studies demonstrated that loss of CB1 defers the normal implantation window in mice, we surmised that CB1 deficiency would influence parturition events. METHODS AND FINDINGS: Exploiting mouse models with targeted deletion of Cnr1, Cnr2 and Ptgs1 encoding CB1, CB2 and cyclooxygenase-1, respectively, we examined consequences of CB1 or CB2 silencing on the onset of parturition. We observed that genetic or pharmacological inactivation of CB1, but not CB2, induced preterm labor in mice. Radioimmunoassay analysis of circulating levels of ovarian steroid hormones revealed that premature birth resulting from CB1 inactivation is correlated with altered progesterone/estrogen ratios prior to parturition. More strikingly, the phenotypic defects of prolonged pregnancy length and parturition failure in mice missing Ptgs1 were corrected by introducing CB1 deficiency into Ptgs1 null mice. In addition, loss of CB1 resulted in aberrant secretions of corticotrophin-releasing hormone and corticosterone during late gestation. The pathophysiological significance of this altered corticotrophin-releasing hormone-driven endocrine activity in the absence of CB1 was evident from our subsequent findings that a selective corticotrophin-releasing hormone antagonist was able to restore the normal parturition timing in Cnr1 deficient mice. In contrast, wild-type females receiving excessive levels of corticosterone induced preterm birth. CONCLUSIONS: CB1 deficiency altering normal progesterone and estrogen levels induces preterm birth in mice. This defect is independent of prostaglandins produced by

  18. Monohydroxylated metabolites of the K2 synthetic cannabinoid JWH-073 retain intermediate to high cannabinoid 1 receptor (CB1R) affinity and exhibit neutral antagonist to partial agonist activity.

    Science.gov (United States)

    Brents, Lisa K; Gallus-Zawada, Anna; Radominska-Pandya, Anna; Vasiljevik, Tamara; Prisinzano, Thomas E; Fantegrossi, William E; Moran, Jeffery H; Prather, Paul L

    2012-04-01

    K2 and several similar purported "incense products" spiked with synthetic cannabinoids are abused as cannabis substitutes. We hypothesized that metabolism of JWH-073, a prevalent cannabinoid found in K2, contributes to toxicity associated with K2 use. Competition receptor binding studies and G-protein activation assays, both performed by employing mouse brain homogenates, were used to determine the affinity and intrinsic activity, respectively, of potential monohydroxylated (M1, M3-M5) and monocarboxylated (M6) metabolites at cannabinoid 1 receptors (CB1Rs). Surprisingly, M1, M4 and M5 retain nanomolar affinity for CB1Rs, while M3 displays micromolar affinity and M6 does not bind to CB1Rs. JWH-073 displays equivalent efficacy to that of the CB1R full agonist CP-55,940, while M1, M3, and M5 act as CB1R partial agonists, and M4 shows little or no intrinsic activity. Further in vitro investigation by Schild analysis revealed that M4 acts as a competitive neutral CB1R antagonist (K(b)∼40nM). In agreement with in vitro studies, M4 also demonstrates CB1R antagonism in vivo by blunting cannabinoid-induced hypothermia in mice. Interestingly, M4 does not block agonist-mediated responses of other measures in the cannabinoid tetrad (e.g., locomotor suppression, catalepsy or analgesia). Finally, also as predicted by in vitro results, M1 exhibits agonist activity in vivo by inducing significant hypothermia and suppression of locomotor activity in mice. In conclusion, the present study indicates that further work examining the physiological effects of synthetic cannabinoid metabolism is warranted. Such a complex mix of metabolically produced CB1R ligands may contribute to the adverse effect profile of JWH-073-containing products.

  19. Cannabinoid receptors CB1 and CB2 form functional heteromers in brain.

    Science.gov (United States)

    Callén, Lucía; Moreno, Estefanía; Barroso-Chinea, Pedro; Moreno-Delgado, David; Cortés, Antoni; Mallol, Josefa; Casadó, Vicent; Lanciego, José Luis; Franco, Rafael; Lluis, Carmen; Canela, Enric I; McCormick, Peter J

    2012-06-15

    Exploring the role of cannabinoid CB(2) receptors in the brain, we present evidence of CB(2) receptor molecular and functional interaction with cannabinoid CB(1) receptors. Using biophysical and biochemical approaches, we discovered that CB(2) receptors can form heteromers with CB(1) receptors in transfected neuronal cells and in rat brain pineal gland, nucleus accumbens, and globus pallidus. Within CB(1)-CB(2) receptor heteromers expressed in a neuronal cell model, agonist co-activation of CB(1) and CB(2) receptors resulted in a negative cross-talk in Akt phosphorylation and neurite outgrowth. Moreover, one specific characteristic of CB(1)-CB(2) receptor heteromers consists of both the ability of CB(1) receptor antagonists to block the effect of CB(2) receptor agonists and, conversely, the ability of CB(2) receptor antagonists to block the effect of CB(1) receptor agonists, showing a bidirectional cross-antagonism phenomenon. Taken together, these data illuminate the mechanism by which CB(2) receptors can negatively modulate CB(1) receptor function.

  20. Action of CB1 and CB2 antagonists/inverse agonists on mantle cell lymphoma

    OpenAIRE

    Chui, Daniel

    2011-01-01

    In this study, the effects of antagonists to the cannabinoid receptors in MCL cell lines were studied. Results presented in this study show that signalling through cannabinoid receptor with antagonists such as SR141716, SR144528 decreases cell viability but hemopressin when analyzing with XTT. The decrease in cell viability by SR141716 is caused by apoptosis triggered after 5 hours of treatment. The CB1 expression was confirmed in all MCL cell lines tested via western blotting but the express...

  1. Allosteric Modulation: An Alternate Approach Targeting the Cannabinoid CB1 Receptor.

    Science.gov (United States)

    Nguyen, Thuy; Li, Jun-Xu; Thomas, Brian F; Wiley, Jenny L; Kenakin, Terry P; Zhang, Yanan

    2016-11-23

    The cannabinoid CB1 receptor is a G protein coupled receptor and plays an important role in many biological processes and physiological functions. A variety of CB1 receptor agonists and antagonists, including endocannabinoids, phytocannabinoids, and synthetic cannabinoids, have been discovered or developed over the past 20 years. In 2005, it was discovered that the CB1 receptor contains allosteric site(s) that can be recognized by small molecules or allosteric modulators. A number of CB1 receptor allosteric modulators, both positive and negative, have since been reported and importantly, they display pharmacological characteristics that are distinct from those of orthosteric agonists and antagonists. Given the psychoactive effects commonly associated with CB1 receptor agonists and antagonists/inverse agonists, allosteric modulation may offer an alternate approach to attain potential therapeutic benefits while avoiding inherent side effects of orthosteric ligands. This review details the complex pharmacological profiles of these allosteric modulators, their structure-activity relationships, and efforts in elucidating binding modes and mechanisms of actions of reported CB1 allosteric modulators. The ultimate development of CB1 receptor allosteric ligands could potentially lead to improved therapies for CB1-mediated neurological disorders.

  2. Stress regulates endocannabinoid-CB1 receptor signaling.

    Science.gov (United States)

    Hillard, Cecilia J

    2014-10-01

    The CB1 cannabinoid receptor is a G protein coupled receptor that is widely expressed throughout the brain. The endogenous ligands for the CB1 receptor (endocannabinoids) are N-arachidonylethanolamine and 2-arachidonoylglycerol; together the endocannabinoids and CB1R subserve activity dependent, retrograde inhibition of neurotransmitter release in the brain. Deficiency of CB1 receptor signaling is associated with anhedonia, anxiety, and persistence of negative memories. CB1 receptor-endocannabinoid signaling is activated by stress and functions to buffer or dampen the behavioral and endocrine effects of acute stress. Its role in regulation of neuronal responses is more complex. Chronic variable stress exposure reduces endocannabinoid-CB1 receptor signaling and it is hypothesized that the resultant deficiency in endocannabinoid signaling contributes to the negative consequences of chronic stress. On the other hand, repeated exposure to the same stress can sensitize CB1 receptor signaling, resulting in dampening of the stress response. Data are reviewed that support the hypothesis that CB1 receptor signaling is stress responsive and that maintaining robust endocannabinoid/CB1 receptor signaling provides resilience against the development of stress-related pathologies.

  3. Chronic ethanol exposure decreases CB1 receptor function at GABAergic synapses in the rat central amygdala.

    Science.gov (United States)

    Varodayan, Florence P; Soni, Neeraj; Bajo, Michal; Luu, George; Madamba, Samuel G; Schweitzer, Paul; Parsons, Loren H; Roberto, Marisa

    2016-07-01

    The endogenous cannabinoids (eCBs) influence the acute response to ethanol and the development of tolerance, dependence and relapse. Chronic alcohol exposure alters eCB levels and Type 1 cannabinoid receptor (CB1 ) expression and function in brain regions associated with addiction. CB1 inhibits GABA release, and GABAergic dysregulation in the central nucleus of the amygdala (CeA) is critical in the transition to alcohol dependence. We investigated possible disruptions in CB1 signaling of rat CeA GABAergic transmission following intermittent ethanol exposure. In the CeA of alcohol-naive rats, CB1 agonist WIN 55,212-2 (WIN) decreased the frequency of spontaneous and miniature GABAA receptor-mediated inhibitory postsynaptic currents (s/mIPSCs). This effect was prevented by CB1 antagonism, but not Type 2 cannabinoid receptor (CB2 ) antagonism. After 2-3 weeks of intermittent ethanol exposure, these WIN inhibitory effects were attenuated, suggesting ethanol-induced impairments in CB1 function. The CB1 antagonist AM251 revealed a tonic eCB/CB1 control of GABAergic transmission in the alcohol-naive CeA that was occluded by calcium chelation in the postsynaptic cell. Chronic ethanol exposure abolished this tonic CB1 influence on mIPSC, but not sIPSC, frequency. Finally, acute ethanol increased CeA GABA release in both naive and ethanol-exposed rats. Although CB1 activation prevented this effect, the AM251- and ethanol-induced GABA release were additive, ruling out a direct participation of CB1 signaling in the ethanol effect. Collectively, these observations demonstrate an important CB1 influence on CeA GABAergic transmission and indicate that the CeA is particularly sensitive to alcohol-induced disruptions of CB1 signaling.

  4. CB1 receptors modulate affective behaviour induced by neuropathic pain.

    Science.gov (United States)

    Rácz, Ildikó; Nent, Elisa; Erxlebe, Edda; Zimmer, Andreas

    2015-05-01

    Patients suffering from chronic pain are often diagnosed with a psychiatric condition, in particular generalized anxiety and major depression. The underlying pathomechanisms contributing to this comorbidity, however, are not entirely clear. In this manuscript we have focussed on the potential role of the cannabinoid receptor CB1, because it is known to modulate neuronal circuits contributing to chronic pain states and affective behaviours. For this purpose we analysed the consequences of a partial sciatic nerve ligation on anxiety- and depression-related behaviours in mice lacking CB1 receptors. Our results show that the development of mechanical hypersensitivity was similar in CB1 deficient mice and wild type controls. However, CB1 knockouts showed much more pronounced behavioural manifestations of anxiety-related behaviours in the light-dark and zero-maze tests, sucrose anhedonia, and disturbed home-cage activity. These results indicate that the endocannabinoid system affects chronic pain-induced mood changes through CB1 receptors.

  5. Advances in research on CB1receptor antagonists%大麻Ⅰ型受体抑制剂研究进展

    Institute of Scientific and Technical Information of China (English)

    张伟; 钟武; 李松

    2007-01-01

    临床试验表明,大麻Ⅰ型受体(CB1)抑制剂利莫那班(rimonabant)在治疗肥胖和戒烟方面具有良好效果[1],CB1受体抑制剂还具有治疗药物成瘾、认知和记忆紊乱、神经错乱等疾病的潜力.CB1受体抑制剂与诸多疾病的相关性大大推进了新的CB1受体抑制剂的发展.本文主要对各种CB1受体抑制剂的结构及活性研究的最新进展进行综述.

  6. CB1 Cannabinoid Receptors and their Associated Proteins

    Science.gov (United States)

    Howlett, Allyn C.; Blume, Lawrence C.; Dalton, George D.

    2011-01-01

    CB1 receptors are G-protein coupled receptors (GPCRs) abundant in neurons, in which they modulate neurotransmission. The CB1 receptor influence on memory and learning is well recognized, and disease states associated with CB1 receptors are observed in addiction disorders, motor dysfunction, schizophrenia, and in bipolar, depression, and anxiety disorders. Beyond the brain, CB1 receptors also function in liver and adipose tissues, vascular as well as cardiac tissue, reproductive tissues and bone. Signal transduction by CB1 receptors occurs through interaction with Gi/o proteins to inhibit adenylyl cyclase, activate mitogen-activated protein kinases (MAPK), inhibit voltage-gated Ca2+ channels, activate K+ currents (Kir), and influence Nitric Oxide (NO) signaling. CB1 receptors are observed in internal organelles as well as plasma membrane. β-Arrestins, adaptor protein AP-3, and G-protein receptor-associated sorting protein 1 (GASP1) modulate cellular trafficking. Cannabinoid Receptor Interacting Protein 1a (CRIP1a) is an accessory protein whose function has not been delineated. Factor Associated with Neutral sphingomyelinase (FAN) regulates ceramide signaling. Such diversity in cellular signaling and modulation by interacting proteins suggests that agonists and allosteric modulators could be developed to specifically regulate unique, cell type-specific responses. PMID:20166926

  7. Effects of Intra-Amygdala Infusion of CB1 Receptor Agonists on the Reconsolidation of Fear-Potentiated Startle

    Science.gov (United States)

    Lin, Hui-Ching; Mao, Sheng-Chun; Gean, Po-Wu

    2006-01-01

    The cannabinoid CB1 receptor has been shown to be critically involved in the extinction of fear memory. Systemic injection of a CB1 receptor antagonist prior to extinction training blocked extinction. Conversely, administration of the cannabinoid uptake inhibitor AM404 facilitated extinction in a dose-dependent manner. Here we show that bilateral…

  8. Endocannabinoid CB1 antagonists inhibit hepatitis C virus production, providing a novel class of antiviral host-targeting agents.

    Science.gov (United States)

    Shahidi, Mahsa; Tay, Enoch S E; Read, Scott A; Ramezani-Moghadam, Mehdi; Chayama, Kazuaki; George, Jacob; Douglas, Mark W

    2014-11-01

    Direct-acting antivirals have significantly improved treatment outcomes in chronic hepatitis C (CHC), but side effects, drug resistance and cost mean that better treatments are still needed. Lipid metabolism is closely linked with hepatitis C virus (HCV) replication, and endocannabinoids are major regulators of lipid homeostasis. The cannabinoid 1 (CB1) receptor mediates these effects in the liver. We have previously shown upregulation of CB1 receptors in the livers of patients with CHC, and in a HCV cell-culture model. Here, we investigated whether CB1 blockade inhibited HCV replication. The antiviral effect of a CB1 antagonist, N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251), was examined in HCV strain JFH1 cell-culture and subgenomic replicon models. The effects on the expression of genes involved in lipid metabolism were also measured. CB1 short hairpin RNA (shRNA) was used to confirm that the effects were specific for the cannabinoid receptor. Treatment with AM251 strongly inhibited HCV RNA (~70 %), viral protein (~80 %), the production of new virus particles (~70 %) and virus infectivity (~90 %). As expected, AM251 reduced the expression of pro-lipogenic genes (SREBP-1c, FASN, SCD1 and ACC1) and stimulated genes promoting lipid oxidation (CPT1 and PPARα). This effect was mediated by AMP-activated protein kinase (AMPK). Stable CB1 knockdown of cells infected with HCV showed reduced levels of HCV RNA compared with controls. Thus, reduced CB1 signalling inhibits HCV replication using either pharmacological inhibitors or CB1 shRNA. This may be due, at least in part, to reduced lipogenesis, mediated by AMPK activation. We suggest that CB1 antagonists may represent an entirely new class of drug with activity against HCV.

  9. The CB1 receptor mediates the peripheral effects of ghrelin on AMPK activity but not on growth hormone release.

    Science.gov (United States)

    Kola, Blerina; Wittman, Gábor; Bodnár, Ibolya; Amin, Faisal; Lim, Chung Thong; Oláh, Márk; Christ-Crain, Mirjam; Lolli, Francesca; van Thuijl, Hinke; Leontiou, Chrysanthia A; Füzesi, Tamás; Dalino, Paolo; Isidori, Andrea M; Harvey-White, Judith; Kunos, George; Nagy, György M; Grossman, Ashley B; Fekete, Csaba; Korbonits, Márta

    2013-12-01

    This study aimed to investigate whether the growth hormone release and metabolic effects of ghrelin on AMPK activity of peripheral tissues are mediated by cannabinoid receptor type 1 (CB1) and the central nervous system. CB1-knockout (KO) and/or wild-type mice were injected peripherally or intracerebroventricularly with ghrelin and CB1 antagonist rimonabant to study tissue AMPK activity and gene expression (transcription factors SREBP1c, transmembrane protein FAS, enzyme PEPCK, and protein HSL). Growth hormone levels were studied both in vivo and in vitro. Peripherally administered ghrelin in liver, heart, and adipose tissue AMPK activity cannot be observed in CB1-KO or CB1 antagonist-treated mice. Intracerebroventricular ghrelin treatment can influence peripheral AMPK activity. This effect is abolished in CB1-KO mice and by intracerebroventricular rimonabant treatment, suggesting that central CB1 receptors also participate in the signaling pathway that mediates the effects of ghrelin on peripheral tissues. Interestingly, in vivo or in vitro growth hormone release is intact in response to ghrelin in CB1-KO animals. Our data suggest that the metabolic effects of ghrelin on AMPK in peripheral tissues are abolished by the lack of functional CB1 receptor via direct peripheral effect and partially through the central nervous system, thus supporting the existence of a possible ghrelin-cannabinoid-CB1-AMPK pathway.

  10. Effects of CB1 and CRF1 receptor antagonists on binge-like eating in rats with limited access to a sweet fat diet: lack of withdrawal-like responses.

    Science.gov (United States)

    Parylak, Sarah L; Cottone, Pietro; Sabino, Valentina; Rice, Kenner C; Zorrilla, Eric P

    2012-09-10

    Positive reinforcement (e.g., appetitive, rewarding properties) has often been hypothesized to maintain excessive intake of palatable foods. Recently, rats receiving intermittent access to high sucrose diets showed binge-like intake with withdrawal-like signs upon cessation of access, suggesting negative reinforcement mechanisms contribute as well. Whether intermittent access to high fat diets also produces withdrawal-like syndromes is controversial. The present study therefore tested the hypothesis that binge-like eating and withdrawal-like anxiety would arise in a novel model of binge eating based on daily 10-min access to a sweet fat diet (35% fat kcal, 31% sucrose kcal). Within 2-3 weeks, female Wistar rats developed binge-like intake comparable to levels seen previously for high sucrose diets (~40% of daily caloric intake within 10 min) plus excess weight gain and adiposity, but absent increased anxiety-like behavior during elevated plus-maze or defensive withdrawal tests after diet withdrawal. Binge-like intake was unaffected by pretreatment with the corticotropin-releasing factor type 1 (CRF(1)) receptor antagonist R121919, and corticosterone responses to restraint stress did not differ between sweet-fat binge rats and chow-fed controls. In contrast, pretreatment with the cannabinoid type 1 (CB(1)) receptor antagonist SR147778 dose-dependently reduced binge-like intake, albeit less effectively than in ad lib chow or sweet fat controls. A priming dose of the sweet fat diet did not precipitate increased anxiety-like behavior, but rather increased plus-maze locomotor activity. The results suggest that CB(1)-dependent positive reinforcement rather than CRF(1)-dependent negative reinforcement mechanisms predominantly maintain excessive intake in this limited access model of sweet-fat diet binges.

  11. Protocol to Study β-Arrestin Recruitment by CB1 and CB2 Cannabinoid Receptors.

    Science.gov (United States)

    Soethoudt, Marjolein; van Gils, Noortje; van der Stelt, Mario; Heitman, Laura H

    2016-01-01

    Cannabinoid CB1 and CB2 receptors are G-protein-coupled receptors (GPCRs) that recruit β-arrestins upon activation by (partial) agonists. β-Arrestin recruitment is induced by phosphorylation of their C-terminal tails, and is associated with the termination of GPCR signaling; yet, it may also activate cellular signaling pathways independent of G-proteins. Here, we describe a detailed protocol to characterize the potency and efficacy of ligands to induce or inhibit β-arrestin recruitment to the human CB1 and CB2 receptors, by using the PathHunter(®) assay. The latter is a cellular assay that can be performed in plates with 384-wells. The PathHunter(®) assay makes use of β-galactosidase complementation, and has a chemiluminescent readout. We used this assay to characterize a set of reference ligands (both agonists and antagonists) on human CB1 and CB2 receptors.

  12. Cannabinoid CB1 receptor-mediated inhibition of hippocampal acetylcholine release is preserved in aged mice

    OpenAIRE

    Redmer, Agnes; Kathmann, Markus; Schlicker, Eberhard

    2003-01-01

    The cannabinoid CB1 receptor inverse agonist/antagonist SR 141716 increases acetylcholine release in rodent hippocampus and improves memory in some experimental paradigms. Since drugs like SR 141716 may represent a novel class of cognition-enhancing drugs, we wanted to check whether the function of the CB1 receptor is preserved during ageing.Hippocampal and striatal slices from 2- to 3- and 24- to 28-month-old C57BL/6J mice were preincubated with [3H]-choline or [3H]-noradrenaline ([3H]-NA) a...

  13. Cannabinoid CB1 receptor signaling dichotomously modulates inhibitory and excitatory synaptic transmission in rat inner retina.

    Science.gov (United States)

    Wang, Xiao-Han; Wu, Yi; Yang, Xiao-Fang; Miao, Yanying; Zhang, Chuan-Qiang; Dong, Ling-Dan; Yang, Xiong-Li; Wang, Zhongfeng

    2016-01-01

    In the inner retina, ganglion cells (RGCs) integrate and process excitatory signal from bipolar cells (BCs) and inhibitory signal from amacrine cells (ACs). Using multiple labeling immunohistochemistry, we first revealed the expression of the cannabinoid CB1 receptor (CB1R) at the terminals of ACs and BCs in rat retina. By patch-clamp techniques, we then showed how the activation of this receptor dichotomously regulated miniature inhibitory postsynaptic currents (mIPSCs), mediated by GABAA receptors and glycine receptors, and miniature excitatory postsynaptic currents (mEPSCs), mediated by AMPA receptors, of RGCs in rat retinal slices. WIN55212-2 (WIN), a CB1R agonist, reduced the mIPSC frequency due to an inhibition of L-type Ca(2+) channels no matter whether AMPA receptors were blocked. In contrast, WIN reduced the mEPSC frequency by suppressing T-type Ca(2+) channels only when inhibitory inputs to RGCs were present, which could be in part due to less T-type Ca(2+) channels of cone BCs, presynaptic to RGCs, being in an inactivation state under such condition. This unique feature of CB1R-mediated retrograde regulation provides a novel mechanism for modulating excitatory synaptic transmission in the inner retina. Moreover, depolarization of RGCs suppressed mIPSCs of these cells, an effect that was eliminated by the CB1R antagonist SR141716, suggesting that endocannabinoid is indeed released from RGCs.

  14. Perspectives of CB1 Antagonist in Treatment of Obesity: Experience of RIO-Asia

    Directory of Open Access Journals (Sweden)

    Changyu Pan

    2011-01-01

    Full Text Available Rimonabant, a selective cannabinoid-1 (CB1 receptor antagonist, has been shown to reduce weight and enhance improvements in cardiometabolic risk parameters in Western populations. This study assessed these effects of rimonabant in Asian population. A total of 643 patients (BMI 25 kg/m2 or greater without diabetes from China, Republic of Korea, and Taiwan were prescribed a hypocaloric diet (600 kcal/day deficit and randomized to rimonabant 20 mg (n=318 or placebo (n=325 for 9months. The primary efficacy variable was weight change from baseline after 9 months of treatment. Results showed that rimonabant group lost more weight than placebo, (LSM ± SEM of −4.7 ± 0.3 kg vs. −1.7 ± 0.3 kg, P<.0001. The 5% and 10% responders were 2 or 3 folds more in the rimonabant group (53.0% vs. 20.0% and 21.5% vs. 5.7%, resp. (P<.0001. Rimonabant also significantly increased HDL-cholesterol, decreased triglycerides and waist circumference,by 7.1%, 10.6%, and 2.8 cm, respectively (P<.0001. This study confirmed the comparable efficacy and safety profile of rimonabant in Asian population to Caucasians. Owing to the recent suspension of all the CB1 antagonists off the pharmaceutical market for weight reduction in Europe and USA, a perspective in drug discovery for intervening peripheral CB1 receptor in the management of obesity is discussed.

  15. Development and preliminary validation of a plate-based CB1/CB2 receptor functional assay.

    Science.gov (United States)

    Dossou, K S S; Devkota, K P; Kavanagh, P V; Beutler, J A; Egan, J M; Moaddel, R

    2013-06-15

    Cannabinoid (CB) receptors are being targeted therapeutically for the treatment of anxiety, obesity, movement disorders, glaucoma, and pain. More recently, cannabinoid agonists have displayed antiproliferative activity against breast cancer and prostate cancer in animal models. To study cannabinoid receptor ligands, we have developed a novel plate-based assay that measures internalization of CB1/CB2 receptors by determining the change in the intracellular levels of the radiolabeled agonists: [(3)H]Win55-212-2 for CB1 and [(3)H]CP55-940 for CB2. The developed plate-based assay was validated by determining IC50 values for known antagonists: AM251, AM281, AM630, and AM6545. The data obtained were consistent with previously reported values, thereby confirming that the assay can be used to determine the functional binding activities (IC50) of antagonists for the CB1 and CB2 receptors. In addition, we demonstrated that the plate-based assay may be used for screening against complex matrices. Specifically, we demonstrated that the plate-based assay was able to identify which extracts of several species of the genus Zanthoxylum had activity at the CB1/CB2 receptors.

  16. Involvement of cannabinoid CB1- and CB2-receptors in the modulation of exocrine pancreatic secretion.

    Science.gov (United States)

    Linari, G; Agostini, S; Amadoro, G; Ciotti, M T; Florenzano, F; Improta, G; Petrella, C; Severini, C; Broccardo, M

    2009-03-01

    The role of the cannabinoid system in the regulation of exocrine pancreatic secretion was investigated by studying the effects of the synthetic CB1- and CB2-receptors agonist, WIN55,212, on amylase secretion in isolated lobules and acini of guinea pig and rat, and the expression of CB-receptors in rat pancreatic tissue by immuno-chemistry and Western-blot analysis in both basal and cerulein (CK)-induced pancreatitis condition. In pancreatic lobules of guinea pig and rat, WIN55,212 significantly inhibited amylase release stimulated by KCl depolarization through inhibition of presynaptic acetylcholine release, but did not modify basal, carbachol- or CK-stimulated amylase secretion. The effect of WIN55,212 was significantly reduced by pre-treatment with selective CB1- and CB2-receptor antagonists. The antagonists, when given alone, did not affect the KCl-evoked response. Conversely, WIN55,212 was unable to affect basal and CK- or carbachol-stimulated amylase release from pancreatic acini of guinea pig and rat. Immunofluorescent staining of rat pancreatic tissues showed that CB1- and CB2-receptors are expressed in lobules and in acinar cells and their presence in acinar cells was also shown by Western-blot analysis. After CK-induced pancreatitis, the expression of CB1-receptors in acinar cells was not changed, whilst a down-regulation of CB2-receptors was observed. In conclusion, the present study shows that WIN55,212 inhibits amylase release from guinea pig and rat pancreatic lobules and, for the first time, that cannabinoid receptors are expressed in lobules of the rat pancreas, suggesting an inhibitory presynaptic role of this receptor system. Finally, in rat pancreatic acinar cells, CB1- and CB2-receptors, expressed both in basal conditions and after CK-induced pancreatitis but inactive on amylase secretion, have an unknown role both in physiological and pathological conditions.

  17. Risperidone treatment increases CB1 receptor binding in rat brain

    DEFF Research Database (Denmark)

    Secher, Anna; Husum, Henriette; Holst, Birgitte

    2010-01-01

    , the ghrelin receptor, neuropeptide Y, adiponectin and proopiomelanocortin. We investigated whether the expression of these factors was affected in rats chronically treated with the antipsychotic risperidone. METHODS: Male Sprague-Dawley rats were treated with risperidone (1.0 mg/kg/day) or vehicle (20......% hydroxypropyl beta-cyclodextrin) for 28 days. Expression of the aforementioned factors were examined together with plasma prolactin and ghrelin levels. RESULTS: No difference in body weight gained during treatment was observed between risperidone and vehicle treated rats, but plasma risperidone levels...... positively correlated with visceral fat mass. Risperidone treatment increased CB(1) receptor binding in the arcuate nucleus (40%), hippocampus (25-30%) and amygdala (35%) without concurrent alterations in the CB(1) receptor mRNA. Risperidone treatment increased adiponectin mRNA. CONCLUSION: The present study...

  18. Novel adamantyl cannabinoids as CB1 receptor probes.

    Science.gov (United States)

    Thakur, Ganesh A; Bajaj, Shama; Paronis, Carol; Peng, Yan; Bowman, Anna L; Barak, Lawrence S; Caron, Marc G; Parrish, Demon; Deschamps, Jeffrey R; Makriyannis, Alexandros

    2013-05-23

    In previous studies, compound 1 (AM411), a 3-(1-adamantyl) analogue of the phytocannabinoid (-)-Δ(8)-tetrahydrocannabinol (Δ(8)-THC), was shown to have improved affinity and selectivity for the CB1 receptor. In this work, we further explored the role of the 1-adamantyl group at the C-3 position in a series of tricyclic cannabinoid analogues modified at the 9-northern aliphatic hydroxyl (NAH) position. Of these, 9-hydroxymethyl hexahydrocannabinol 11 (AM4054) exhibited high CB1 affinity and full agonist profile. In the cAMP assay, the 9-hydroxymethyl cannabinol analogue 24 (AM4089) had a partial agonist profile, with high affinity and moderate selectivity for rCB1 over hCB2. In vivo results in rat models of hypothermia and analgesia were congruent with in vitro data. Our in vivo data indicate that 3-(1-adamantyl) substitution, within NAH cannabinergics, imparts improved pharmacological profiles when compared to the corresponding, traditionally used 3-dimethylheptyl analogues and identifies 11 and 24 as potentially useful in vivo CB1 cannabinergic probes.

  19. Central and peripheral consequences of the chronic blockade of CB1 cannabinoid receptor with rimonabant or taranabant.

    Science.gov (United States)

    Martín-García, Elena; Burokas, Aurelijus; Martín, Miquel; Berrendero, Fernando; Rubí, Blanca; Kiesselbach, Christoph; Heyne, Andrea; Gispert, Juan Domingo; Millán, Olga; Maldonado, Rafael

    2010-03-01

    The endocannabinoid system plays a crucial role in the pathophysiology of obesity. However, the clinical use of cannabinoid antagonists has been recently stopped because of its central side-effects. The aim of this study was to compare the effects of a chronic treatment with the CB(1) cannabinoid antagonist rimonabant or the CB(1) inverse agonist taranabant in diet-induced obese female rats to clarify the biological consequences of CB(1) blockade at central and peripheral levels. As expected, chronic treatment with rimonabant and taranabant reduced body weight and fat content. Interestingly, a decrease in the number of CB(1) receptors and its functional activity was observed in all the brain areas investigated after chronic taranabant treatment in both lean and obese rats. In contrast, chronic treatment with rimonabant did not modify the density of CB(1) cannabinoid receptor binding, and decreased its functional activity to a lower degree than taranabant. Six weeks after rimonabant and taranabant withdrawal, CB(1) receptor density and activity recovered to basal levels. These results reveal differential adaptive changes in CB(1) cannabinoid receptors after chronic treatment with rimonabant and taranabant that could be related to the central side-effects reported with the use of these cannabinoid antagonists.

  20. CONSTITUTIVE ACTIVITY AT THE CANNABINOID CB1 RECEPTOR IS REQUIRED FOR BEHAVIORAL RESPONSE TO NOXIOUS CHEMICAL STIMULATION OF TRPV1: ANTINOCICEPTIVE ACTIONS OF CB1 INVERSE AGONISTS

    OpenAIRE

    Fioravanti, Beatriz; De Felice, Milena; Stucky, Cheryl L; Medler, Karen A.; Luo, Miaw-chyi; Gardell, Luis R.; Ibrahim, Mohab; Malan, T. Phil; Yamamura, Henry I.; Ossipov, Michael H.; King, Tamara; Lai, Josephine; Porreca, Frank; Vanderah, Todd W

    2008-01-01

    The potential modulation of TRPV1 nociceptive activity by the CB1 receptor was investigated here using CB1 wildtype (WT) and knock-out (KO) mice as well as selective CB1 inverse agonists. No significant differences were detected in baseline thermal thresholds of ICR, CB1WT or CB1KO mice. Intraplantar capsaicin produced dose- and time-related paw flinch responses in ICR and CB1WT mice and induced plasma extravasation yet minimal responses were seen in CB1KO animals with no apparent differences...

  1. Relationships between glucose, energy intake and dietary composition in obese adults with type 2 diabetes receiving the cannabinoid 1 (CB1 receptor antagonist, rimonabant

    Directory of Open Access Journals (Sweden)

    Heppenstall Charlotte

    2012-07-01

    Full Text Available Abstract Background Weight loss is often difficult to achieve in individuals with type 2 diabetes and anti-obesity drugs are often advocated to support dietary intervention. Despite the extensive use of centrally acting anti-obesity drugs, there is little evidence of how they affect dietary composition. We investigated changes in energy intake and dietary composition of macro- and micronutrients following therapy with the endocannabinoid receptor blocker, rimonabant. Methods 20 obese patients with type 2 diabetes were studied before and after 6 months dietary intervention with rimonabant. Dietary intervention was supervised by a diabetes dietician. Five-day food diaries were completed at baseline and at 6 months and dietary analysis was performed using computer software (Dietplan 6. Results After 6 months, (compared with baseline there were reductions in weight (107 ± 21Kg versus 112 ± 21, p  Conclusions In obese patients with type 2 diabetes, rimonabant in combination with dietary intervention led to reduced intake of energy and most macronutrients. Despite this, macronutrient composition of the diet was unaltered. These dietary changes (especially carbohydrate restriction were associated with weight loss and favourable metabolic effects.

  2. Cannabinoid receptor-interacting protein 1a modulates CB1 receptor signaling and regulation.

    Science.gov (United States)

    Smith, Tricia H; Blume, Lawrence C; Straiker, Alex; Cox, Jordan O; David, Bethany G; McVoy, Julie R Secor; Sayers, Katherine W; Poklis, Justin L; Abdullah, Rehab A; Egertová, Michaela; Chen, Ching-Kang; Mackie, Ken; Elphick, Maurice R; Howlett, Allyn C; Selley, Dana E

    2015-04-01

    Cannabinoid CB1 receptors (CB1Rs) mediate the presynaptic effects of endocannabinoids in the central nervous system (CNS) and most behavioral effects of exogenous cannabinoids. Cannabinoid receptor-interacting protein 1a (CRIP1a) binds to the CB1R C-terminus and can attenuate constitutive CB1R-mediated inhibition of Ca(2+) channel activity. We now demonstrate cellular colocalization of CRIP1a at neuronal elements in the CNS and show that CRIP1a inhibits both constitutive and agonist-stimulated CB1R-mediated guanine nucleotide-binding regulatory protein (G-protein) activity. Stable overexpression of CRIP1a in human embryonic kidney (HEK)-293 cells stably expressing CB1Rs (CB1-HEK), or in N18TG2 cells endogenously expressing CB1Rs, decreased CB1R-mediated G-protein activation (measured by agonist-stimulated [(35)S]GTPγS (guanylyl-5'-[O-thio]-triphosphate) binding) in both cell lines and attenuated inverse agonism by rimonabant in CB1-HEK cells. Conversely, small-interfering RNA-mediated knockdown of CRIP1a in N18TG2 cells enhanced CB1R-mediated G-protein activation. These effects were not attributable to differences in CB1R expression or endocannabinoid tone because CB1R levels did not differ between cell lines varying in CRIP1a expression, and endocannabinoid levels were undetectable (CB1-HEK) or unchanged (N18TG2) by CRIP1a overexpression. In CB1-HEK cells, 4-hour pretreatment with cannabinoid agonists downregulated CB1Rs and desensitized agonist-stimulated [(35)S]GTPγS binding. CRIP1a overexpression attenuated CB1R downregulation without altering CB1R desensitization. Finally, in cultured autaptic hippocampal neurons, CRIP1a overexpression attenuated both depolarization-induced suppression of excitation and inhibition of excitatory synaptic activity induced by exogenous application of cannabinoid but not by adenosine A1 agonists. These results confirm that CRIP1a inhibits constitutive CB1R activity and demonstrate that CRIP1a can also inhibit agonist

  3. Binding thermodynamics at the human cannabinoid CB1 and CB2 receptors.

    Science.gov (United States)

    Merighi, Stefania; Simioni, Carolina; Gessi, Stefania; Varani, Katia; Borea, Pier Andrea

    2010-02-01

    The thermodynamic parameters DeltaG degrees , DeltaH degrees and DeltaS degrees of the binding equilibrium of agonists and antagonists at cannabinoid CB(1) and CB(2) receptors were determined by means of affinity measurements at different temperatures and van't Hoff plots were constructed. Affinity constants were measured on CHO cells transfected with the human CB(1) and CB(2) receptors by inhibition assays of the binding of the cannabinoid receptor agonist [(3)H]-CP-55,940. van't Hoff plots were linear for agonists and antagonists in the temperature range 0-30 degrees C. The thermodynamic parameters for CB(1) receptors fall in the ranges 17< or =DeltaH degrees < or =59 kJ/mol and 213< or =DeltaS degrees < or =361 kJ/mol for agonists and -52< or =DeltaH degrees < or =-26 kJ/mol and -12< or =DeltaS degrees < or =38 kJ/mol for antagonists. The thermodynamic parameters for CB(2) receptors fall in the ranges 27< or =DeltaH degrees < or =48 kJ/mol and 234< or =DeltaS degrees < or =300 kJ/mol for agonists and -19< or =DeltaH degrees < or =-17 kJ/mol and 43< or =DeltaS degrees < or =74 kJ/mol for antagonists. Collectively, these data show that agonist binding is always totally entropy-driven while antagonist binding is enthalpy and entropy-driven, indicating that CB(1) and CB(2) receptors are thermodynamically discriminated. These data could give new details on the nature of the forces driving the CB(1) and CB(2) binding at a molecular level. Enthalpy, entropy, free energy and binding affinity for each ligand to its receptor can all be assessed and therefore the optimal binding profile discovered. Carrying out these binding investigations as early as possible in the discovery process increases the probability that a lead compound will become a successful pharmaceutical compound.

  4. Cannabinoid Receptors CB1 and CB2 Modulate the Electroretinographic Waves in Vervet Monkeys

    Directory of Open Access Journals (Sweden)

    Joseph Bouskila

    2016-01-01

    Full Text Available The expression patterns of the cannabinoid receptor type 1 (CB1R and the cannabinoid receptor type 2 (CB2R are well documented in rodents and primates. In vervet monkeys, CB1R is present in the retinal neurons (photoreceptors, horizontal cells, bipolar cells, amacrine cells, and ganglion cells and CB2R is exclusively found in the retinal glia (Müller cells. However, the role of these cannabinoid receptors in normal primate retinal function remains elusive. Using full-field electroretinography in adult vervet monkeys, we recorded changes in neural activity following the blockade of CB1R and CB2R by the intravitreal administration of their antagonists (AM251 and AM630, resp. in photopic and scotopic conditions. Our results show that AM251 increases the photopic a-wave amplitude at high flash intensities, whereas AM630 increases the amplitude of both the photopic a- and b-waves. In scotopic conditions, both blockers increased the b-wave amplitude but did not change the a-wave amplitude. These findings suggest an important role of CB1R and CB2R in primate retinal function.

  5. Cannabinoid Receptors CB1 and CB2 Modulate the Electroretinographic Waves in Vervet Monkeys.

    Science.gov (United States)

    Bouskila, Joseph; Harrar, Vanessa; Javadi, Pasha; Beierschmitt, Amy; Palmour, Roberta; Casanova, Christian; Bouchard, Jean-François; Ptito, Maurice

    2016-01-01

    The expression patterns of the cannabinoid receptor type 1 (CB1R) and the cannabinoid receptor type 2 (CB2R) are well documented in rodents and primates. In vervet monkeys, CB1R is present in the retinal neurons (photoreceptors, horizontal cells, bipolar cells, amacrine cells, and ganglion cells) and CB2R is exclusively found in the retinal glia (Müller cells). However, the role of these cannabinoid receptors in normal primate retinal function remains elusive. Using full-field electroretinography in adult vervet monkeys, we recorded changes in neural activity following the blockade of CB1R and CB2R by the intravitreal administration of their antagonists (AM251 and AM630, resp.) in photopic and scotopic conditions. Our results show that AM251 increases the photopic a-wave amplitude at high flash intensities, whereas AM630 increases the amplitude of both the photopic a- and b-waves. In scotopic conditions, both blockers increased the b-wave amplitude but did not change the a-wave amplitude. These findings suggest an important role of CB1R and CB2R in primate retinal function.

  6. Benzyl-1,2,4-triazoles as CB1 Cannabinoid Receptor Ligands: Preparation and In Vitro Pharmacological Evaluation

    Science.gov (United States)

    Hernandez-Folgado, Laura; Decara, Juan; Rodríguez de Fonseca, Fernando; Goya, Pilar; Jagerovic, Nadine

    2016-01-01

    In a previous study, we have identified 3-alkyl-1,5-diaryl-1H-1,2,4-triazoles to be a novel class of cannabinoid type 1 receptor (CB1R) antagonists. In order to expand the number of cannabinoid ligands with a central 1,2,4-triazole scaffold, we have synthesized a novel series of 1-benzyl-1H-1,2,4-triazoles, and some of them were evaluated by CB1R radioligand binding assays. Compound 12a showed the most interesting pharmacological properties, possessing a CB1R affinity in the nanomolar range. PMID:27127651

  7. The central cannabinoid CB1 receptor is required for diet-induced obesity and rimonabant's antiobesity effects in mice.

    Science.gov (United States)

    Pang, Zhen; Wu, Nancy N; Zhao, Weiguang; Chain, David C; Schaffer, Erica; Zhang, Xin; Yamdagni, Preeti; Palejwala, Vaseem A; Fan, Chunpeng; Favara, Sarah G; Dressler, Holly M; Economides, Kyriakos D; Weinstock, Daniel; Cavallo, Jean S; Naimi, Souad; Galzin, Anne-Marie; Guillot, Etienne; Pruniaux, Marie-Pierre; Tocci, Michael J; Polites, H Greg

    2011-10-01

    Cannabinoid receptor CB1 is expressed abundantly in the brain and presumably in the peripheral tissues responsible for energy metabolism. It is unclear if the antiobesity effects of rimonabant, a CB1 antagonist, are mediated through the central or the peripheral CB1 receptors. To address this question, we generated transgenic mice with central nervous system (CNS)-specific knockdown (KD) of CB1, by expressing an artificial microRNA (AMIR) under the control of the neuronal Thy1.2 promoter. In the mutant mice, CB1 expression was reduced in the brain and spinal cord, whereas no change was observed in the superior cervical ganglia (SCG), sympathetic trunk, enteric nervous system, and pancreatic ganglia. In contrast to the neuronal tissues, CB1 was undetectable in the brown adipose tissue (BAT) or the liver. Consistent with the selective loss of central CB1, agonist-induced hypothermia was attenuated in the mutant mice, but the agonist-induced delay of gastrointestinal transit (GIT), a primarily peripheral nervous system-mediated effect, was not. Compared to wild-type (WT) littermates, the mutant mice displayed reduced body weight (BW), adiposity, and feeding efficiency, and when fed a high-fat diet (HFD), showed decreased plasma insulin, leptin, cholesterol, and triglyceride levels, and elevated adiponectin levels. Furthermore, the therapeutic effects of rimonabant on food intake (FI), BW, and serum parameters were markedly reduced and correlated with the degree of CB1 KD. Thus, KD of CB1 in the CNS recapitulates the metabolic phenotype of CB1 knockout (KO) mice and diminishes rimonabant's efficacy, indicating that blockade of central CB1 is required for rimonabant's antiobesity actions.

  8. Homology Modeling and Docking Studies of Cannabinoid Receptor CB1%大麻素受体CB1三维结构的同源模建及其对接研究

    Institute of Scientific and Technical Information of China (English)

    涂国刚; 李少华

    2011-01-01

    大麻素CB1受体属于G蛋白偶联受体.以牛视紫红质的晶体结构为模板,利用同源模建法对CB1受体的三维结构进行了模拟,并采用分子动力学方法对模型进行了修正和优化.在此基础上,分析了活性位点的组成和结构,研究了拮抗剂利莫那班与CBi受体的对接,明确了CB1受体与利莫那班结合时起重要作用的氨基酸残基.发现利莫那班与CB1受体残基Lys192形成氢键相互作用是CB1受体拮抗剂的重要分子作用基础.%CB1 receptor belongs to G protein-coupled receptor.Using bovine rhodopsin as structural template, the 3D structure of CB1 receptor was built by homology modeling, and refined using molecular dynamics method.On the basis of the modeling, the components and strncture of active site in CB1 receptor were analyzed, and the docking of rimonabant with CB1 receptor was investigated.The binding pattern revealed important residues that interacted with the rimonabant.The hydrogen bonding interaction between Lys192 and rimonabant is crucial for CB1 receptor antagonist.

  9. Cannabinoid CB1 Receptors Are Localized in Striated Muscle Mitochondria and Regulate Mitochondrial Respiration

    OpenAIRE

    Mendizabal-Zubiaga, Juan; Melser, Su; Bénard, Giovanni; Ramos, Almudena; Reguero, Leire; Arrabal, Sergio; Elezgarai, Izaskun; Gerrikagoitia, Inmaculada; Suarez, Juan; Rodríguez de Fonseca, Fernando; Puente, Nagore; Marsicano, Giovanni; Grandes, Pedro

    2016-01-01

    The cannabinoid type 1 (CB1) receptor is widely distributed in the brain and peripheral organs where it regulates cellular functions and metabolism. In the brain, CB1 is mainly localized on presynaptic axon terminals but is also found on mitochondria (mtCB1), where it regulates cellular respiration and energy production. Likewise, CB1 is localized on muscle mitochondria, but very little is known about it. The aim of this study was to further investigate in detail the distribution and function...

  10. Pharmacological Blockade of Cannabinoid CB1 Receptors in Diet-Induced Obesity Regulates Mitochondrial Dihydrolipoamide Dehydrogenase in Muscle.

    Science.gov (United States)

    Arrabal, Sergio; Lucena, Miguel Angel; Canduela, Miren Josune; Ramos-Uriarte, Almudena; Rivera, Patricia; Serrano, Antonia; Pavón, Francisco Javier; Decara, Juan; Vargas, Antonio; Baixeras, Elena; Martín-Rufián, Mercedes; Márquez, Javier; Fernández-Llébrez, Pedro; De Roos, Baukje; Grandes, Pedro; Rodríguez de Fonseca, Fernando; Suárez, Juan

    2015-01-01

    Cannabinoid CB1 receptors peripherally modulate energy metabolism. Here, we investigated the role of CB1 receptors in the expression of glucose/pyruvate/tricarboxylic acid (TCA) metabolism in rat abdominal muscle. Dihydrolipoamide dehydrogenase (DLD), a flavoprotein component (E3) of α-ketoacid dehydrogenase complexes with diaphorase activity in mitochondria, was specifically analyzed. After assessing the effectiveness of the CB1 receptor antagonist AM251 (3 mg kg(-1), 14 days) on food intake and body weight, we could identified seven key enzymes from either glycolytic pathway or TCA cycle--regulated by both diet and CB1 receptor activity--through comprehensive proteomic approaches involving two-dimensional electrophoresis and MALDI-TOF/LC-ESI trap mass spectrometry. These enzymes were glucose 6-phosphate isomerase (GPI), triosephosphate isomerase (TPI), enolase (Eno3), lactate dehydrogenase (LDHa), glyoxalase-1 (Glo1) and the mitochondrial DLD, whose expressions were modified by AM251 in hypercaloric diet-induced obesity. Specifically, AM251 blocked high-carbohydrate diet (HCD)-induced expression of GPI, TPI, Eno3 and LDHa, suggesting a down-regulation of glucose/pyruvate/lactate pathways under glucose availability. AM251 reversed the HCD-inhibited expression of Glo1 and DLD in the muscle, and the DLD and CB1 receptor expression in the mitochondrial fraction. Interestingly, we identified the presence of CB1 receptors at the membrane of striate muscle mitochondria. DLD over-expression was confirmed in muscle of CB1-/- mice. AM251 increased the pyruvate dehydrogenase and glutathione reductase activity in C2C12 myotubes, and the diaphorase/oxidative activity in the mitochondria fraction. These results indicated an up-regulation of methylglyoxal and TCA cycle activity. Findings suggest that CB1 receptors in muscle modulate glucose/pyruvate/lactate pathways and mitochondrial oxidative activity by targeting DLD.

  11. Pharmacological Blockade of Cannabinoid CB1 Receptors in Diet-Induced Obesity Regulates Mitochondrial Dihydrolipoamide Dehydrogenase in Muscle.

    Directory of Open Access Journals (Sweden)

    Sergio Arrabal

    Full Text Available Cannabinoid CB1 receptors peripherally modulate energy metabolism. Here, we investigated the role of CB1 receptors in the expression of glucose/pyruvate/tricarboxylic acid (TCA metabolism in rat abdominal muscle. Dihydrolipoamide dehydrogenase (DLD, a flavoprotein component (E3 of α-ketoacid dehydrogenase complexes with diaphorase activity in mitochondria, was specifically analyzed. After assessing the effectiveness of the CB1 receptor antagonist AM251 (3 mg kg(-1, 14 days on food intake and body weight, we could identified seven key enzymes from either glycolytic pathway or TCA cycle--regulated by both diet and CB1 receptor activity--through comprehensive proteomic approaches involving two-dimensional electrophoresis and MALDI-TOF/LC-ESI trap mass spectrometry. These enzymes were glucose 6-phosphate isomerase (GPI, triosephosphate isomerase (TPI, enolase (Eno3, lactate dehydrogenase (LDHa, glyoxalase-1 (Glo1 and the mitochondrial DLD, whose expressions were modified by AM251 in hypercaloric diet-induced obesity. Specifically, AM251 blocked high-carbohydrate diet (HCD-induced expression of GPI, TPI, Eno3 and LDHa, suggesting a down-regulation of glucose/pyruvate/lactate pathways under glucose availability. AM251 reversed the HCD-inhibited expression of Glo1 and DLD in the muscle, and the DLD and CB1 receptor expression in the mitochondrial fraction. Interestingly, we identified the presence of CB1 receptors at the membrane of striate muscle mitochondria. DLD over-expression was confirmed in muscle of CB1-/- mice. AM251 increased the pyruvate dehydrogenase and glutathione reductase activity in C2C12 myotubes, and the diaphorase/oxidative activity in the mitochondria fraction. These results indicated an up-regulation of methylglyoxal and TCA cycle activity. Findings suggest that CB1 receptors in muscle modulate glucose/pyruvate/lactate pathways and mitochondrial oxidative activity by targeting DLD.

  12. CB1 cannabinoid receptor participates in the vascular hyporeactivity resulting from hemorrhagic shock in rats

    Institute of Scientific and Technical Information of China (English)

    HOU Li-chao; LI Nan; ZHENG Li-na; LU Yan; XIE Ke-liang; WANG Yue-min; JI Gen-lin; XIONG Li-ze

    2009-01-01

    Background Vascular hyporeactivity, which occurs in the terminal stage of hemorrhagic shock, is believed to be critical for treating hemorrhagic shock. The present study was designed to examine whether the CB1 cannabinoid receptor (CB1R) was involved in the development of vascular hyporeactivity in rats suffering from hemorrhagic shock.Methods Sixteen animals were randomly divided into two groups (n=8 in each group): sham-operated (Sham) and hemorrhagic shock (HS) groups. Hemorrhagic shock was induced by bleeding. The mean arterial pressure (MAP) was reduced to and stabilized at (25±5) mmHg for 2 hours. The vascular reactivity was determined by the response of MAP to norepinephrine (NE). In later experiments another twelve animals were used in which the changes of CB1R mRNA and protein in aorta and superior mesenteric artery (SMA) were analyzed by RT-PCR and Western blotting. In addition, we investigated the effects of a CB1R antagonist on the vascular hyporeactivity and survival rates in rats with hemorrhagic shock. Survival rates were analyzed by the Fisher's exact probability test. The MAP response was analyzed by one-way analysis of variance (ANOVA).Results Vascular hyporeactivity developed in all animals suffering from hemorrhagic shock. The expression of CB1R mRNA and protein in aorta and 2-3 branches of the SMA were significantly increased in the HS group after the development of vascular hyporeactivity when compared to those in Sham group. When SR141716A or AM251 was administered, the MAP response to NE was (41.75±4.08) mmHg or (44.78±1.80) mmHg respectively, which was higher than that in saline groups with (4.31±0.36) mmHg (P<0.01). We also showed an increased 4-hour survival rate in the SR141716A or AM251-treated group with 20% or 30%, but with a statistically significant difference present between the AM251-treated and saline groups (P<0.05).Conclusions CB1R is involved in vascular hyporeactivity resulting from hemorrhagic shock in rats, and CB1R

  13. Structural dynamics and energetics underlying allosteric inactivation of the cannabinoid receptor CB1.

    Science.gov (United States)

    Fay, Jonathan F; Farrens, David L

    2015-07-07

    G protein-coupled receptors (GPCRs) are surprisingly flexible molecules that can do much more than simply turn on G proteins. Some even exhibit biased signaling, wherein the same receptor preferentially activates different G-protein or arrestin signaling pathways depending on the type of ligand bound. Why this behavior occurs is still unclear, but it can happen with both traditional ligands and ligands that bind allosterically outside the orthosteric receptor binding pocket. Here, we looked for structural mechanisms underlying these phenomena in the marijuana receptor CB1. Our work focused on the allosteric ligand Org 27569, which has an unusual effect on CB1-it simultaneously increases agonist binding, decreases G--protein activation, and induces biased signaling. Using classical pharmacological binding studies, we find that Org 27569 binds to a unique allosteric site on CB1 and show that it can act alone (without need for agonist cobinding). Through mutagenesis studies, we find that the ability of Org 27569 to bind is related to how much receptor is in an active conformation that can couple with G protein. Using these data, we estimated the energy differences between the inactive and active states. Finally, site-directed fluorescence labeling studies show the CB1 structure stabilized by Org 27569 is different and unique from that stabilized by antagonist or agonist. Specifically, transmembrane helix 6 (TM6) movements associated with G-protein activation are blocked, but at the same time, helix 8/TM7 movements are enhanced, suggesting a possible mechanism for the ability of Org 27569 to induce biased signaling.

  14. Cannabinoid receptor CB1 mediates baseline and activity-induced survival of new neurons in adult hippocampal neurogenesis

    Directory of Open Access Journals (Sweden)

    Müller Anke

    2010-06-01

    Full Text Available Abstract Background Adult neurogenesis is a particular example of brain plasticity that is partially modulated by the endocannabinoid system. Whereas the impact of synthetic cannabinoids on the neuronal progenitor cells has been described, there has been lack of information about the action of plant-derived extracts on neurogenesis. Therefore we here focused on the effects of Δ9-tetrahydrocannabinol (THC and Cannabidiol (CBD fed to female C57Bl/6 and Nestin-GFP-reporter mice on proliferation and maturation of neuronal progenitor cells and spatial learning performance. In addition we used cannabinoid receptor 1 (CB1 deficient mice and treatment with CB1 antagonist AM251 in Nestin-GFP-reporter mice to investigate the role of the CB1 receptor in adult neurogenesis in detail. Results THC and CBD differed in their effects on spatial learning and adult neurogenesis. CBD did not impair learning but increased adult neurogenesis, whereas THC reduced learning without affecting adult neurogenesis. We found the neurogenic effect of CBD to be dependent on the CB1 receptor, which is expressed over the whole dentate gyrus. Similarly, the neurogenic effect of environmental enrichment and voluntary wheel running depends on the presence of the CB1 receptor. We found that in the absence of CB1 receptors, cell proliferation was increased and neuronal differentiation reduced, which could be related to CB1 receptor mediated signaling in Doublecortin (DCX-expressing intermediate progenitor cells. Conclusion CB1 affected the stages of adult neurogenesis that involve intermediate highly proliferative progenitor cells and the survival and maturation of new neurons. The pro-neurogenic effects of CBD might explain some of the positive therapeutic features of CBD-based compounds.

  15. Induction of proteinuria by cannabinoid receptors 1 signaling activation in CB1 transgenic mice.

    Science.gov (United States)

    Hsu, Yung-Chien; Lei, Chen-Chou; Shih, Ya-Hsueh; Ho, Cheng; Lin, Chun-Liang

    2015-02-01

    Proteinuria is not only a sign of kidney damage but is also involved in the progression of renal disease as an independent pathologic factor. Although patients with mutated type 1 cannabinoid receptors (CB1) polymorphism are associated with renal microvascular damage, the biologic role of CB1 signaling in proteinuria remains uncharacterized till now. Herein, we investigate whether CB1 participates in glomerular proteinuria in CB1 transgenic mice and treatment with CB1 agonist WIN55212-2 rat, neither of which are diabetic models. The CB1 transgenic mice and rats treated with CB1 agonist WIN55212-2 had higher kidney weight and urinary protein concentrations but not blood glucose levels compared with the wild-type group. A combination of laser-capture microsdissection, quantitative reverse transcription-polymerase chain reaction, immunoblotting and immunohistochemical validation revealed that CB1 transgenic mice and rats treated with CB1 agonist WIN55212-2 had higher vascular endothelial growth factor (VEGF) expression in renal glomeruli than that of the wild-type group. Geneticorpharmacological activation of CB1 by transgenic CB1 mice or treatment with WIN55212-2 reduced nephrin expression in the renal glomeruli compared with that of the wild-type group in the glomerular mesanglium. Taken together, CB1 transgenic mice and rats treated with CB1 agonist WIN55212-2 induced proteinuria with upregulation of CB1 resulting in impaired nephrin expression, by inducing excess VEGF reaction in the renal glomeruli. Genetic and pharmacological manipulation of CB1 signaling revealed VEGF-dependent nephrin depression of glomerulopathy. Controlling CB1 activity can be used an alternative strategy for sustaining renal function in the presence of CB1 activation.

  16. Bi-directional CB1 receptor-mediated cardiovascular effects of cannabinoids in anaesthetized rats: role of the paraventricular nucleus.

    Science.gov (United States)

    Grzeda, E; Schlicker, E; Luczaj, W; Harasim, E; Baranowska-Kuczko, M; Malinowska, B

    2015-06-01

    The activation of cannabinoid CB1 receptors decreases and increases blood pressure (BP) in anaesthetized and conscious rats, respectively. The aim of our study was to check the possible involvement of CB1 receptors in the paraventricular nucleus of the hypothalamus (PVN) in the cardiovascular effects of cannabinoids in rats. Methanandamide (metabolically stable analogue of the endocannabinoid anandamide) and the synthetic cannabinoid receptor agonist CP55940 were microinjected into the PVN of urethane-anaesthetized rats twice (S1 and S2, 20 min apart). Receptor antagonists were administered intravenously (i.v.) 5 min before S1. Methanandamide and CP55940 decreased blood pressure by 15 - 20%. The CB1 receptor antagonist AM251 reversed the depressor effect into a pressor response of 20 - 30%. The pressor effect of CP55940 observed in the presence of AM251 i.v. was reduced by AM251 given additionally into the PVN but not by the i.v. injection of the CB2 antagonist SR144528 or the vanilloid TRPV1 antagonist ruthenium red. In the presence of the peripherally restricted CB1 receptor antagonist AM6545, CP55940 given into the PVN increased BP by 40%. AM6545 reversed the decrease in BP induced by CP55940 i.v. into a marked increase. Bilateral chemical lesion of the PVN by kainic acid abolished all cardiovascular effects of CP55940 i.v. In conclusion, the cannabinoid CP55940 administered to the PVN of urethane-anaesthetized rats can induce depressor and pressor effects. The direction of the response probably depends on the sympathetic tone. The centrally induced hypertensive response of CP55940 can, in addition, be masked by peripheral CB1 receptors.

  17. The CB1 receptor as an important mediator of hedonic reward processing.

    Science.gov (United States)

    Friemel, Chris M; Zimmer, Andreas; Schneider, Miriam

    2014-09-01

    The endocannabinoid (ECB) system has emerged recently as a key mediator for reward processing. It is well known that cannabinoids affect appetitive learning processes and can induce reinforcing and rewarding effects. However, the involvement of the ECB system in hedonic aspects of reward-related behavior is not completely understood. With the present study, we investigated the modulatory role of the ECB system on hedonic perception, measured by the pleasure attenuated startle (PAS) paradigm for a palatable food reward. Here, a conditioned odor is thought to induce a pleasant affective state that attenuates an aversive reflex-the acoustic startle response. Modulatory effects of the CB1 receptor antagonist/inverse agonist SR1411716 and the cannabinoid agonist WIN 55 212-2 on PAS were examined in rats. PAS was also measured in CB1 receptor knockout (KO) and wild-type (WT) mice. Pharmacological inhibition as well as the absence of CB1 receptors was found to reduce PAS, whereas WIN 55 212-2 administration increased PAS. Finally, presentation of a conditioned reward cue was found to induce striatal FosB/ΔFosB expression in WT mice, but not in KO mice, indicating a reduced stimulation of reward-related brain regions in conditioned KO mice by odor presentation. We here show that in addition to our previous studies in rats, PAS may also serve as a valuable and suitable measure to assess hedonic processing in mice. Our data further indicate that the ECB system, and in particular CB1 receptor signaling, appears to be highly important for the mediation of hedonic aspects of reward processing.

  18. Selective Estrogen Receptor Modulators: Cannabinoid Receptor Inverse Agonists with Differential CB1 and CB2 Selectivity

    Science.gov (United States)

    Franks, Lirit N.; Ford, Benjamin M.; Prather, Paul L.

    2016-01-01

    Selective estrogen receptor modulators (SERMs) are used to treat estrogen receptor (ER)-positive breast cancer and osteoporosis. Interestingly, tamoxifen and newer classes of SERMs also exhibit cytotoxic effects in cancers devoid of ERs, indicating a non-estrogenic mechanism of action. Indicative of a potential ER-independent target, reports demonstrate that tamoxifen binds to cannabinoid receptors (CBRs) with affinity in the low μM range and acts as an inverse agonist. To identify cannabinoids with improved pharmacological properties relative to tamoxifen, and further investigate the use of different SERM scaffolds for future cannabinoid drug development, this study characterized the affinity and activity of SERMs in newer structural classes at CBRs. Fourteen SERMs from five structurally distinct classes were screened for binding to human CBRs. Compounds from four of five SERM classes examined bound to CBRs. Subsequent studies fully characterized CBR affinity and activity of one compound from each class. Ospemifine (a triphenylethylene) selectively bound to CB1Rs, while bazedoxifine (an indole) bound to CB2Rs with highest affinity. Nafoxidine (a tetrahydronaphthalene) and raloxifene (RAL; a benzothiaphene) bound to CB1 and CB2Rs non-selectively. All four compounds acted as inverse agonists at CB1 and CB2Rs, reducing basal G-protein activity with IC50 values in the nM to low μM range. Ospemifine, bazedoxifene and RAL also acted as inverse agonists to elevate basal intracellular cAMP levels in intact CHO-hCB2 cells. The four SERMs examined also acted as CB1 and CB2R antagonists in the cAMP assay, producing rightward shifts in the concentration-effect curve of the CBR agonist CP-55,940. In conclusion, newer classes of SERMs exhibit improved pharmacological characteristics (e.g., in CBR affinity and selectivity) relative to initial studies with tamoxifen, and thus suggest that different SERM scaffolds may be useful for development of safe and selective drugs acting

  19. Differential CB1 and CB2 cannabinoid receptor-inotropic response of rat isolated atria: endogenous signal transduction pathways.

    Science.gov (United States)

    Sterin-Borda, Leonor; Del Zar, Claudia F; Borda, Enri

    2005-06-15

    In this study, we have determined the contractile effects of CB1 and CB2 cannabinoid receptor activation on rat isolated atria and the different signaling pathways involved. Anandamide did not has significantly effect on atria contractility, however, the treatment with both CB1 (AM251) or CB2 (AM630) receptor antagonists, the endocannabinoids triggered stimulation or inhibition on contractility respectively. The ACEA stimulation of CB1 receptor exerted decrease on contractility, that significantly correlated with the decrement of cAMP and the stimulation of nitric oxide synthase (NOS) and the accumulation of cyclic GMP (cGMP). On the contrary, JWH 015 stimulation of CB2 receptor triggered positive contractile response that significantly correlated with the increase cAMP production. The inhibiton of adenylate cyclase activity impaired the JWH 015 activation of CB1 receptor induced positive contractile effect, while inhibitors of phospholipase C (PLC), NOS and soluble nitric oxide (NO)-sensitive guanylate cyclase blocked the dose-response curves of ACEA on contractility. Those inhibitors also attenuated the CB1 receptor-dependent increase in activation of NOS and cGMP accumulation. These results suggest that CB2 receptor agonist mediated positive contractile effect associated with increased production on cAMP while CB1 receptor agonist mediated decrease on contractility associated with decreased cAMP accumulation and increase production of NO and cGMP; that occur secondarily to stimulation of PLC, NOS and soluble guanylate cyclase. Data give pharmacological evidence for the existence of functional CB1 and CB2 cannabinoid receptors in rat isolated atria and may contribute to a better understanding the effects of cannabinoids in the cardiovascular system.

  20. Cannabinoid CB1 and CB2 receptor ligand specificity and the development of CB2-selective agonists.

    Science.gov (United States)

    Ashton, John C; Wright, Jason L; McPartland, John M; Tyndall, Joel D A

    2008-01-01

    Cannabinoids in current use such as nabilone activate both CB1 and CB2 receptors. Selective CB2 activation may provide some of the therapeutic effects of cannabinoids, such as their immuno-modulatory properties, without the psychoactive effects of CB1 activation. Therefore, cannabinoid CB2 receptors represent an attractive target for drug development. However, selective and potent CB2 agonists remain in development. CB1 and CB2 differ considerably in their amino acid sequence and tertiary structures. Therefore, clinical development of potent and selective CB2 agonists is probable. Mutational and ligand binding studies, functional mapping, and computer modelling have revealed key residues and domains in cannabinoid receptors that are involved in agonist and antagonist binding to CB1 and CB2. In addition, CB2 has undergone more rapid evolution, and results for ligand binding and efficacy cannot be automatically extrapolated from rat or mouse CB2 to human. Furthermore, loss of CB1 affinity is a crucial property for CB2-selective ligands, and although rat CB1 is 97% homologous with human CB1, critical differences do exist, with potential for further exploitation in drug design. In this paper we briefly review previous cannabinoid receptor models and mutation/binding studies. We also review binding affinity ratios with respect to CB1 and CB2. We then employ our own models to illustrate key cannabinoid receptor residues and binding subdomains that are involved in these differences in binding affinities and discuss how these might be exploited in the development of CB2 specific ligands. Published reports for species specific binding affinities for CB2 are scarce, and we argue that this needs to be corrected prior to the progression of CB2 agonists from pre-clinical to clinical research.

  1. Differential Control of Cocaine Self-Administration by GABAergic and Glutamatergic CB1 Cannabinoid Receptors.

    Science.gov (United States)

    Martín-García, Elena; Bourgoin, Lucie; Cathala, Adeline; Kasanetz, Fernando; Mondesir, Miguel; Gutiérrez-Rodriguez, Ana; Reguero, Leire; Fiancette, Jean-François; Grandes, Pedro; Spampinato, Umberto; Maldonado, Rafael; Piazza, Pier Vincenzo; Marsicano, Giovanni; Deroche-Gamonet, Véronique

    2016-08-01

    The type 1 cannabinoid receptor (CB1) modulates numerous neurobehavioral processes and is therefore explored as a target for the treatment of several mental and neurological diseases. However, previous studies have investigated CB1 by targeting it globally, regardless of its two main neuronal localizations on glutamatergic and GABAergic neurons. In the context of cocaine addiction this lack of selectivity is critical since glutamatergic and GABAergic neuronal transmission is involved in different aspects of the disease. To determine whether CB1 exerts different control on cocaine seeking according to its two main neuronal localizations, we used mutant mice with deleted CB1 in cortical glutamatergic neurons (Glu-CB1) or in forebrain GABAergic neurons (GABA-CB1). In Glu-CB1, gene deletion concerns the dorsal telencephalon, including neocortex, paleocortex, archicortex, hippocampal formation and the cortical portions of the amygdala. In GABA-CB1, it concerns several cortical and non-cortical areas including the dorsal striatum, nucleus accumbens, thalamic, and hypothalamic nuclei. We tested complementary components of cocaine self-administration, separating the influence of primary and conditioned effects. Mechanisms underlying each phenotype were explored using in vivo microdialysis and ex vivo electrophysiology. We show that CB1 expression in forebrain GABAergic neurons controls mouse sensitivity to cocaine, while CB1 expression in cortical glutamatergic neurons controls associative learning processes. In accordance, in the nucleus accumbens, GABA-CB1 receptors control cocaine-induced dopamine release and Glu-CB1 receptors control AMPAR/NMDAR ratio; a marker of synaptic plasticity. Our findings demonstrate a critical distinction of the altered balance of Glu-CB1 and GABA-CB1 activity that could participate in the vulnerability to cocaine abuse and addiction. Moreover, these novel insights advance our understanding of CB1 neuropathophysiology.

  2. Bivalent ligands that target μ opioid (MOP) and cannabinoid1 (CB1) receptors are potent analgesics devoid of tolerance.

    Science.gov (United States)

    Le Naour, Morgan; Akgün, Eyup; Yekkirala, Ajay; Lunzer, Mary M; Powers, Mike D; Kalyuzhny, Alexander E; Portoghese, Philip S

    2013-07-11

    Given that μ opioid (MOP) and canabinoid (CB1) receptors are colocalized in various regions of the central nervous system and have been reported to associate as heteromer (MOP-CB1) in cultured cells, the possibility of functional, endogenous MOP-CB1 in nociception and other pharmacologic effects has been raised. As a first step in investigating this possibility, we have synthesized a series of bivalent ligands 1-5 that contain both μ agonist and CB1 antagonist pharmacophores for use as tools to study the functional interaction between MOP and CB1 receptors in vivo. Immunofluorescent studies on HEK293 cells coexpressing both receptors suggested 5 (20-atom spacer) to be the only member of the series that bridges the protomers of the heteromer. Antinociceptive testing in mice revealed 5 to be the most potent member of the series. As neither a mixture of monovalent ligands 9 + 10 nor bivalents 2-5 produced tolerance in mice, MOR-CB1 apparently is not an important target for reducing tolerance.

  3. Dorsolateral periaqueductal gray matter CB1 and TRPV1 receptors exert opposite modulation on expression of contextual fear conditioning.

    Science.gov (United States)

    Uliana, D L; Hott, S C; Lisboa, S F; Resstel, L B M

    2016-04-01

    Cannabinoid type 1 (CB1) and Transient Potential Vanilloid type 1 (TRPV1) receptors in the dorsolateral periaqueductal gray (dlPAG) matter are involved in the modulation of conditioned response. Both CB1 and TRPV1 receptors are related to glutamate release and nitric oxide (NO) synthesis. It was previously demonstrated that both NMDA glutamate receptors and NO are involved in the conditioned emotional response. Therefore, one aim of this work was to verify whether dlPAG CB1 and TRPV1 receptors modulate the expression of contextual conditioned emotional response. Moreover, we also investigated the involvement of NMDA receptors and the NO pathway in this response. Male Wistar rats with local dlPAG guide cannula were submitted to contextual fear conditioning. Following 24 h, a polyethylene catheter was implanted in the femoral artery for cardiovascular recordings. After an additional 24 h, drugs were administered in the dlPAG and freezing behavior and autonomic responses were recorded during chamber re-exposure. Both a CB1 antagonist (AM251) and a TRPV1 agonist (Capsaicin; CPS) increased the expression of a conditioned emotional response. This response was prevented by an NMDA antagonist, a preferential neuronal NO synthase inhibitor, an NO scavenger and a soluble guanylate cyclase inhibitor (sGC). Furthermore, pretreatment with a TRPV1 antagonist also prevented the increased conditioned emotional response induced by AM251. Considering that GABA can counterbalance glutamate effects, we also investigated whether GABAA receptors were involved in the effect of a higher dose of AM251. Pretreatment with a GABAA receptor antagonist caused an increased conditioned emotional response by AM251. Our results support the possibility that dlPAG CB1 and TRPV1 receptors are involved in the expression of conditioned emotional response through the NMDA/NO/sGC pathway. Moreover, the opposite effects exerted by GABA and glutamate could produce different outcomes of drugs modulating eCBs.

  4. CB1 cannabinoid receptor expression in the striatum: Association with corticostriatal circuits and developmental regulation

    Directory of Open Access Journals (Sweden)

    Vincent eVan Waes

    2012-03-01

    Full Text Available Corticostriatal circuits mediate various aspects of goal-directed behavior and are critically important for basal ganglia-related disorders. Activity in these circuits is regulated by the endocannabinoid system via stimulation of CB1 cannabinoid receptors. CB1 receptors are highly expressed in projection neurons and select interneurons of the striatum, but expression levels vary considerably between different striatal regions (functional domains. We investigated CB1 receptor expression within specific corticostriatal circuits by mapping CB1 mRNA levels in striatal sectors defined by their cortical inputs in rats. We also assessed changes in CB1 expression in the striatum during development. Our results show that CB1 expression is highest in juveniles (P25 and then progressively decreases towards adolescent (P40 and adult (P70 levels. At every age, CB1 receptors are predominantly expressed in sensorimotor striatal sectors, with considerably lower expression in associative and limbic sectors. Moreover, for most corticostriatal circuits there is an inverse relationship between cortical and striatal expression levels. Thus, striatal sectors with high CB1 expression (sensorimotor sectors tend to receive inputs from cortical areas with low expression, while striatal sectors with low expression (associative/limbic sectors receive inputs from cortical regions with higher expression (medial prefrontal cortex. In so far as CB1 mRNA levels reflect receptor function, our findings suggest differential CB1 signaling between different developmental stages and between sensorimotor and associative/limbic circuits. The regional distribution of CB1 receptor expression in the striatum further suggests that, in sensorimotor sectors, CB1 receptors mostly regulate GABA inputs from local axon collaterals of projection neurons, whereas in associative/limbic sectors, CB1 regulation of GABA inputs from interneurons and glutamate inputs may be more important.

  5. Basolateral amygdala CB1 cannabinoid receptors mediate nicotine-induced place preference.

    Science.gov (United States)

    Hashemizadeh, Shiva; Sardari, Maryam; Rezayof, Ameneh

    2014-06-03

    In the present study, the effects of bilateral microinjections of cannabinoid CB1 receptor agonist and antagonist into the basolateral amygdala (intra-BLA) on nicotine-induced place preference were examined in rats. A conditioned place preference (CPP) apparatus was used for the assessment of rewarding effects of the drugs in adult male Wistar rats. Subcutaneous (s.c.) administration of nicotine (0.2mg/kg) induced a significant CPP, without any effect on the locomotor activity during the testing phase. Intra-BLA microinjection of a non-selective cannabinoid CB1/CB2 receptor agonist, WIN 55,212-2 (0.1-0.5 μg/rat) with an ineffective dose of nicotine (0.1mg/kg, s.c.) induced a significant place preference. On the other hand, intra-BLA administration of AM251 (20-60 ng/rat), a selective cannabinoid CB1 receptor antagonist inhibited the acquisition of nicotine-induced place preference. It should be considered that the microinjection of the same doses of WIN 55,212-2 or AM251 into the BLA, by itself had no effect on the CPP score. The administration of a higher dose of AM251 (60 ng/rat) during the acquisition decreased the locomotor activity of animals on the testing phase. Interestingly, the microinjection of AM251 (20 and 40 ng/rat), but not WIN55,212-2 (0.1-0.5 μg/rat), into the BLA inhibited the expression of nicotine-induced place preference without any effect on the locomotor activity. Taken together, these findings support the possible role of endogenous cannabinoid system of the BLA in the acquisition and the expression of nicotine-induced place preference. Furthermore, it seems that there is a functional interaction between the BLA cannabinoid receptors and nicotine in producing the rewarding effects.

  6. Cannabinoid CB1 Receptors Are Localized in Striated Muscle Mitochondria and Regulate Mitochondrial Respiration

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    Juan Mendizabal-Zubiaga

    2016-10-01

    Full Text Available The cannabinoid type 1 (CB1 receptor is widely distributed in the brain and peripheral organs where it regulates cellular functions and metabolism. In the brain, CB1 is mainly localized on presynaptic axon terminals but is also found on mitochondria (mtCB1, where it regulates cellular respiration and energy production. Likewise, CB1 is localized on muscle mitochondria, but very little is known about it. The aim of this study was to further investigate in detail the distribution and functional role of mtCB1 in three different striated muscles. Immunoelectron microscopy for CB1 was used in skeletal muscles (gastrocnemius and rectus abdominis and myocardium from wild-type and CB1-KO mice. Functional assessments were performed in mitochondria purified from the heart of the mice and the mitochondrial oxygen consumption upon application of different acute delta-9-tetrahidrocannabinol (Δ9-THC concentrations (100 nM or 200 nM was monitored. About 26% of the mitochondrial profiles in gastrocnemius, 22% in the rectus abdominis and 17% in the myocardium expressed CB1. Furthermore, the proportion of mtCB1 versus total CB1 immunoparticles was about 60% in the gastrocnemius, 55% in the rectus abdominis and 78% in the myocardium. Importantly, the CB1 immunolabeling pattern disappeared in muscles of CB1-KO mice. Functionally, acute 100 nM or 200 nM THC treatment specifically decreased mitochondria coupled respiration between 12% and 15% in wild-type isolated mitochondria of myocardial muscles but no significant difference was noticed between THC treated and vehicle in mitochondria isolated from CB1-KO heart. Furthermore, gene expression of key enzymes involved in pyruvate synthesis, tricarboxylic acid (TCA cycle and mitochondrial respiratory chain was evaluated in the striated muscle of CB1-WT and CB1-KO. CB1-KO showed an increase in the gene expression of Eno3, Pkm2, and Pdha1, suggesting an increased production of pyruvate. In contrast, no significant

  7. Cannabinoid CB1 Receptors Are Localized in Striated Muscle Mitochondria and Regulate Mitochondrial Respiration

    Science.gov (United States)

    Mendizabal-Zubiaga, Juan; Melser, Su; Bénard, Giovanni; Ramos, Almudena; Reguero, Leire; Arrabal, Sergio; Elezgarai, Izaskun; Gerrikagoitia, Inmaculada; Suarez, Juan; Rodríguez De Fonseca, Fernando; Puente, Nagore; Marsicano, Giovanni; Grandes, Pedro

    2016-01-01

    The cannabinoid type 1 (CB1) receptor is widely distributed in the brain and peripheral organs where it regulates cellular functions and metabolism. In the brain, CB1 is mainly localized on presynaptic axon terminals but is also found on mitochondria (mtCB1), where it regulates cellular respiration and energy production. Likewise, CB1 is localized on muscle mitochondria, but very little is known about it. The aim of this study was to further investigate in detail the distribution and functional role of mtCB1 in three different striated muscles. Immunoelectron microscopy for CB1 was used in skeletal muscles (gastrocnemius and rectus abdominis) and myocardium from wild-type and CB1-KO mice. Functional assessments were performed in mitochondria purified from the heart of the mice and the mitochondrial oxygen consumption upon application of different acute delta-9-tetrahydrocannabinol (Δ9-THC) concentrations (100 nM or 200 nM) was monitored. About 26% of the mitochondrial profiles in gastrocnemius, 22% in the rectus abdominis and 17% in the myocardium expressed CB1. Furthermore, the proportion of mtCB1 versus total CB1 immunoparticles was about 60% in the gastrocnemius, 55% in the rectus abdominis and 78% in the myocardium. Importantly, the CB1 immunolabeling pattern disappeared in muscles of CB1-KO mice. Functionally, acute 100 nM or 200 nM THC treatment specifically decreased mitochondria coupled respiration between 12 and 15% in wild-type isolated mitochondria of myocardial muscles but no significant difference was noticed between THC treated and vehicle in mitochondria isolated from CB1-KO heart. Furthermore, gene expression of key enzymes involved in pyruvate synthesis, tricarboxylic acid (TCA) cycle and mitochondrial respiratory chain was evaluated in the striated muscle of CB1-WT and CB1-KO. CB1-KO showed an increase in the gene expression of Eno3, Pkm2, and Pdha1, suggesting an increased production of pyruvate. In contrast, no significant difference was

  8. CB1 receptor deficiency decreases wheel-running activity: consequences on emotional behaviours and hippocampal neurogenesis.

    Science.gov (United States)

    Dubreucq, Sarah; Koehl, Muriel; Abrous, Djoher N; Marsicano, Giovanni; Chaouloff, Francis

    2010-07-01

    Chronic voluntary wheel-running activity has been reported to hypersensitise central CB1 receptors in mice. On the other hand, pharmacological findings suggest that the CB1 receptor could be involved in wheel-running behaviour and in running-induced neurogenesis in the hippocampus. We analysed wheel-running behaviour for 6 weeks and measured its consequences on hippocampal neurogenesis in CB1 knockout (CB1(-/-)) animals, compared to wild-type (CB1(+/+)) littermates. Because wheel running has been shown to affect locomotor reactivity in novel environments, memory for aversive events and depression-like behaviours, we also assessed these behaviours in control and running CB1(+/+) and CB1(-/-) mice. When compared with running CB1(+/+) mice, the distance covered weekly by CB1(-/-) mice was decreased by 30-40%, an observation accounted for by decreased time spent and maximal velocity on the wheels. Analyses of running distances with respect to the light/dark cycle revealed that mutant covered less distance throughout both the inactive and the active phases of that cycle. Locomotion in an activity cage, exploration in an open field, and immobility time in the forced swim test proved insensitive to chronic wheel running in either genotype. Wheel running, per se, did not influence the expression and extinction of cued fear memory but counteracted in a time-dependent manner the deficiency of extinction measured in CB1(-/-) mice. Hippocampal neurogenesis, assessed by doublecortin labelling of immature neurons in the dentate gyrus, was lowered by 40% in control CB1(-/-) mice, compared to control CB1(+/+) mice. Although CB1(-/-) mice ran less than their wild-type littermates, the 6-week running protocol increased neurogenesis to similar extents (37-39%) in both genotypes. This study suggests that mouse CB1 receptors control wheel running but not its neurogenic consequences in the hippocampus.

  9. Controlled downregulation of the cannabinoid CB1 receptor provides a promising approach for the treatment of obesity and obesity-derived type 2 diabetes.

    Science.gov (United States)

    Lu, Dai; Dopart, Rachel; Kendall, Debra A

    2016-01-01

    Increased activity of the endocannabinoid system has emerged as a pathogenic factor in visceral obesity, which is a risk factor for type 2 diabetes mellitus (T2DM). The endocannabinoid system is composed of at least two Gprotein-coupled receptors (GPCRs), the cannabinoid receptor type 1 (CB1), and the cannabinoid receptor type 2 (CB2). Downregulation of CB1 activity in rodents and humans has proven efficacious to reduce food intake, abdominal adiposity, fasting glucose levels, and cardiometabolic risk factors. Unfortunately, downregulation of CB1 activity by universally active CB1 inverse agonists has been found to elicit psychiatric side effects, which led to the termination of using globally active CB1 inverse agonists to treat diet-induced obesity. Interestingly, preclinical studies have shown that downregulation of CB1 activity by CB1 neutral antagonists or peripherally restricted CB1 inverse agonists provided similar anorectic effects and metabolic benefits without psychiatric side effects seen in globally active CB1 inverse agonists. Furthermore, downregulation of CB1 activity may ease endoplasmic reticulum and mitochondrial stress which are contributors to obesity-induced insulin resistance and type 2 diabetes. This suggests new approaches for cannabinoid-based therapy in the management of obesity and obesity-related metabolic disorders including type 2 diabetes.

  10. The dynamic nature of type 1 cannabinoid receptor (CB1) gene transcription

    OpenAIRE

    2012-01-01

    The type 1 cannabinoid receptor (CB1) is an integral component of the endocannabinoid system that modulates several functions in the CNS and periphery. The majority of our knowledge of the endocannabinoid system involves ligand–receptor binding, mechanisms of signal transduction, and protein–protein interactions. In contrast, comparatively little is known about regulation of CB1 gene expression. The levels and anatomical distribution of CB1 mRNA and protein are developmental stage-specific an...

  11. Cannabinoid receptor interacting protein suppresses agonist-driven CB1 receptor internalization and regulates receptor replenishment in an agonist-biased manner.

    Science.gov (United States)

    Blume, Lawrence C; Leone-Kabler, Sandra; Luessen, Deborah J; Marrs, Glen S; Lyons, Erica; Bass, Caroline E; Chen, Rong; Selley, Dana E; Howlett, Allyn C

    2016-11-01

    Cannabinoid receptor interacting protein 1a (CRIP1a) is a CB1 receptor (CB1 R) distal C-terminus-associated protein that modulates CB1 R signaling via G proteins, and CB1 R down-regulation but not desensitization (Blume et al. [2015] Cell Signal., 27, 716-726; Smith et al. [2015] Mol. Pharmacol., 87, 747-765). In this study, we determined the involvement of CRIP1a in CB1 R plasma membrane trafficking. To follow the effects of agonists and antagonists on cell surface CB1 Rs, we utilized the genetically homogeneous cloned neuronal cell line N18TG2, which endogenously expresses both CB1 R and CRIP1a, and exhibits a well-characterized endocannabinoid signaling system. We developed stable CRIP1a-over-expressing and CRIP1a-siRNA-silenced knockdown clones to investigate gene dose effects of CRIP1a on CB1 R plasma membrane expression. Results indicate that CP55940 or WIN55212-2 (10 nM, 5 min) reduced cell surface CB1 R by a dynamin- and clathrin-dependent process, and this was attenuated by CRIP1a over-expression. CP55940-mediated cell surface CB1 R loss was followed by a cycloheximide-sensitive recovery of surface receptors (30-120 min), suggesting the requirement for new protein synthesis. In contrast, WIN55212-2-mediated cell surface CB1 Rs recovered only in CRIP1a knockdown cells. Changes in CRIP1a expression levels did not affect a transient rimonabant (10 nM)-mediated increase in cell surface CB1 Rs, which is postulated to be as a result of rimonabant effects on 'non-agonist-driven' internalization. These studies demonstrate a novel role for CRIP1a in agonist-driven CB1 R cell surface regulation postulated to occur by two mechanisms: 1) attenuating internalization that is agonist-mediated, but not that in the absence of exogenous agonists, and 2) biased agonist-dependent trafficking of de novo synthesized receptor to the cell surface.

  12. Altered gene expression and functional activity of opioid receptors in the cerebellum of CB1 cannabinoid receptor knockout mice after acute treatments with cannabinoids.

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    Páldyová, Estera; Bereczki, E; Sántha, M; Wenger, T; Borsodi, Anna; Benyhe, S

    2007-01-01

    Numerous studies have shown functional links between the cannabinoid and opioid systems. The goal of this study was to evaluate whether acute treatments by endogenous cannabinoid agonist, selective CB1 or CB2 receptor antagonists modulate the expression of mu- (MOR) and delta- (DOR) opioid receptor mRNA levels and functional activity in the cerebellum of transgenic mice deficient in the CB1 type of cannabis receptors. We examined the effect of noladin ether (endogenous cannabinoid agonist) pretreatment on MOR and DOR mRNA expression by using reverse transcription and real-time polimerase chain reaction (PCR) and the ability of subsequent application of the opioid agonists to activate G-proteins, as measured by [35S]GTPgammaS binding, in wild-type (CB1+/+) and CB1 cannabinoid receptor deficient (CB1-/-, 'knockout', K.O.) mice. The acute administration of noladin ether markedly reduced MOR-mediated G-protein activation and caused a significant increase in the level of MOR mRNAs in the cerebella of wildtype, but not in the CB1-/- mice. No significant differences were observed in DOR functional activity and mRNA expression in wild-type animals. In CB1-/- mice the expression of DOR mRNA increased after noladin ether treatment, but no changes were found in DOR functional activity. In addition, Rimonabant (selective central cannabinoid CB1 receptor antagonist) and SR144528 (selective peripheral cannabinoid CB2 receptor antagonist) caused significant potentiation in MOR functional activity in the wild-type animals, whereas DOR mediated G-protein activation was increased in the CB1-/- mice. In contrast, Rimonabant and SR144528 decreased the MOR and DOR mRNA expressions in both CB1+/+ and CB1-/- mice. Taken together, these results indicate that acute treatment with cannabinoids causes alterations in MOR and DOR mRNA expression and functional activity in the cerebella of wild-type and CB1 knockout mice indicating indirect interactions between these two signaling systems.

  13. Astroglial type-1 cannabinoid receptor (CB1): A new player in the tripartite synapse.

    Science.gov (United States)

    Oliveira da Cruz, J F; Robin, L M; Drago, F; Marsicano, G; Metna-Laurent, M

    2016-05-26

    The endocannabinoid system is an important regulator of physiological functions. In the brain, this control is mainly exerted through the type-1-cannabinoid (CB1) receptors. CB1 receptors are abundant at neuron terminals where their stimulation inhibits neurotransmitter release. However, CB1 receptors are also expressed in astrocytes and recent studies showed that astroglial cannabinoid signaling is a key element of the tripartite synapse. In this review we discuss the different mechanisms by which astroglial CB1 receptors control synaptic transmission and plasticity. The recent involvement of astroglial CB1 receptors in the effects of cannabinoids on memory highlights their key roles in cognitive processes and further indicates that astrocytes are central active elements of high-order brain functions.

  14. Brain regional differences in CB1 receptor adaptation and regulation of transcription

    OpenAIRE

    Lazenka, M.F.; Selley, D.E.; Sim-Selley, L J

    2012-01-01

    Cannabinoid CB1 receptors (CB1Rs) are expressed throughout the brain and mediate the central effects of cannabinoids, including Δ9-tetrahydrocannabinol (THC), the main psychoactive constituent of marijuana. Repeated THC administration produces tolerance to cannabinoid-mediated effects, although the magnitude of tolerance varies by effect. Consistent with this observation, CB1R desensitization and downregulation, as well induction of immediate early genes (IEGs), varies by brain region. Zif268...

  15. Computational analysis of the CB1 carboxyl-terminus in the receptor-G protein complex.

    Science.gov (United States)

    Shim, Joong-Youn; Khurana, Leepakshi; Kendall, Debra A

    2016-04-01

    Despite the important role of the carboxyl-terminus (Ct) of the activated brain cannabinoid receptor one (CB1) in the regulation of G protein signaling, a structural understanding of interactions with G proteins is lacking. This is largely due to the highly flexible nature of the CB1 Ct that dynamically adapts its conformation to the presence of G proteins. In the present study, we explored how the CB1 Ct can interact with the G protein by building on our prior modeling of the CB1-Gi complex (Shim, Ahn, and Kendall, The Journal of Biological Chemistry 2013;288:32449-32465) to incorporate a complete CB1 Ct (Glu416(Ct)-Leu472(Ct)). Based on the structural constraints from NMR studies, we employed ROSETTA to predict tertiary folds, ZDOCK to predict docking orientation, and molecular dynamics (MD) simulations to obtain two distinct plausible models of CB1 Ct in the CB1-Gi complex. The resulting models were consistent with the NMR-determined helical structure (H9) in the middle region of the CB1 Ct. The CB1 Ct directly interacted with both Gα and Gβ and stabilized the receptor at the Gi interface. The results of site-directed mutagenesis studies of Glu416(Ct), Asp423(Ct), Asp428(Ct), and Arg444(Ct) of CB1 Ct suggested that the CB1 Ct can influence receptor-G protein coupling by stabilizing the receptor at the Gi interface. This research provided, for the first time, models of the CB1 Ct in contact with the G protein.

  16. Antihyperalgesic effect of CB1 receptor activation involves the modulation of P2X3 receptor in the primary afferent neuron.

    Science.gov (United States)

    Oliveira-Fusaro, Maria Cláudia Gonçalves; Zanoni, Cristiane Isabel Silva; Dos Santos, Gilson Gonçalves; Manzo, Luis Paulo; Araldi, Dionéia; Bonet, Ivan José Magayewski; Tambeli, Cláudia Herrera; Dias, Elayne Vieira; Parada, Carlos Amilcar

    2017-03-05

    Cannabinoid system is a potential target for pain control. Cannabinoid receptor 1 (CB1) activation play a role in the analgesic effect of cannabinoids once it is expressed in primary afferent neurons. This study investigates whether the anti-hyperalgesic effect of CB1 receptor activation involves P2X3 receptor in primary afferent neurons. Mechanical hyperalgesia was evaluated by electronic von Frey test. Cannabinoid effect was evaluated using anandamide or ACEA, a non-selective or a selective CB1 receptor agonists, respectively; AM251, a CB1 receptor antagonist, and antisense ODN for CB1 receptor. Calcium imaging assay was performed to evaluated α,β-meATP-responsive cultured DRG neurons pretreated with ACEA. Anandamide or ACEA administered in peripheral tissue reduced the carrageenan-induced mechanical hyperalgesia. The reduction in the carrageenan-induced hyperalgesia induced by ACEA was completely reversed by administration of AM251 as well as by the intrathecal treatment with antisense ODN for CB1 receptor. Also, ACEA reduced the mechanical hyperalgesia induced by bradykinin and by α,β-meATP, a P2X3 receptor non-selective agonist, but not by tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β) and chemokine-induced chemoattractant-1 (CINC-1). Finally, CB1 receptors are co-localized with P2X3 receptors in DRG small-diameter neurons and the treatment with ACEA reduced the number of α,β-meATP-responsive cultured DRG neurons. Our data suggest that the analgesic effect of CB1 receptor activation is mediated by a negative modulation of the P2X3 receptor in the primary afferent neurons.

  17. The endocannabinoid N-arachidonoyldopamine (NADA) exerts neuroprotective effects after excitotoxic neuronal damage via cannabinoid receptor 1 (CB(1)).

    Science.gov (United States)

    Grabiec, Urszula; Koch, Marco; Kallendrusch, Sonja; Kraft, Robert; Hill, Kerstin; Merkwitz, Claudia; Ghadban, Chalid; Lutz, Beat; Straiker, Alex; Dehghani, Faramarz

    2012-03-01

    Endocannabinoids exert numerous effects in the CNS under physiological and pathological conditions. The aim of the present study was to examine whether the endocannabinoid N-arachidonoyldopamine (NADA) may protect neurons in excitotoxically lesioned organotypic hippocampal slice cultures (OHSC). OHSC were excitotoxically lesioned by application of N-methyl-d-aspartate (NMDA, 50 μM) for 4 h and subsequently treated with different NADA concentrations (0.1 pM-50 μM) alone or in combination with cannabinoid receptor antagonists. NADA protected dentate gyrus granule cells and caused a slight reduction in the number of microglial cells. The number of degenerated neurons significantly decreased between 100 pM and 10 μM NADA (p NADA mediated neuroprotection, we applied the cannabinoid (CB) receptor 1 (CB(1)) inverse agonist/antagonist AM251, CB(2) inverse agonist/antagonist AM630, abnormal-cannabidiol (abn-CBD)-sensitive receptor antagonist O-1918, transient receptor potential channel V1 (TRPV1) antagonist 6-iodonordihydrocapsaicin and A1 (TRPA1) antagonist HC-030031. Neuroprotective properties of low (1 nM) but not high (10 μM) NADA concentrations were solely blocked by AM251 and were absent in CB(1)(-/-) mice. AM630, O-1918, 6-iodonordihydrocapsaicin and HC-030031 showed no effects at all NADA concentrations applied. Our findings demonstrate that NADA protects dentate gyrus granule cells by acting via CB(1). NADA reduced the number of microglial cells at distinct concentrations. TRPV1 and TRPA1 were not involved in NADA mediated neuroprotection. Thus, our data implicate that NADA mediated activation of neuronal CB(1) may serve as a novel pharmacological target to mitigate symptoms of neuronal damage.

  18. Modulation of NMDA and AMPA-mediated synaptic transmission by CB1 receptors in frontal cortical pyramidal cells.

    Science.gov (United States)

    Li, Qiang; Yan, Haidun; Wilson, Wilkie A; Swartzwelder, H Scott

    2010-06-25

    Although the endogenous cannabinoid system modulates a variety of physiological and pharmacological processes, the specific role of cannabinoid CB1 receptors in the modulation of glutamatergic neurotransmission and neural plasticity is not well understood. Using whole-cell patch clamp recording techniques, evoked or spontaneous excitatory postsynaptic currents (eEPSCs or sEPSCs) were recorded from visualized, layer II/III pyramidal cells in frontal cortical slices from rat brain. Bath application of the CB1 receptor agonist, WIN 55212-2 (WIN), reduced the amplitude of NMDA receptor-mediated EPSCs in a concentration-dependent manner. When co-applied with the specific CB1 antagonists, AM251 or AM281, WIN did not suppress NMDA receptor-mediated EPSCs. WIN also reduced the amplitude of evoked AMPA receptor-mediated EPSCs, an effect that was also reversed by AM251. Both the frequency and amplitude of spontaneous AMPA receptor-mediated EPSCs were significantly reduced by WIN. In contrast, WIN reduced the frequency, but not the amplitude of miniature EPSCs, suggesting that the suppression of glutamatergic activity by CB1 receptors in the frontal neocortex is mediated by a presynaptic mechanism. Taken together, these data indicate a critical role for endocannabinoid signaling in the regulation of excitatory synaptic transmission in frontal neocortex, and suggest a possible neuronal mechanism whereby THC regulates cortical function.

  19. CB1 cannabinoid receptors are involved in neuroleptic-induced enhancement of brain neurotensin

    Directory of Open Access Journals (Sweden)

    Parichehr Hassanzadeh

    2014-03-01

    Full Text Available Objective(s: Targeting the neuropeptide systems has been shown to be useful for the development of more effective antipsychotic drugs. Neurotensin, an endogenous neuropeptide, appears to be involved in the mechanism of action of antipsychotics. However, the available data provide conflicting results and the mechanism(s by which antipsychotics affect brain neurotensin neurotransmission have not been identified. Therefore, we aimed to investigate the effects of fluphenazine and amisulpride on brain regional contents of neurotensin considering the role of cannabinoid CB1 receptors which interact with neurotensin neurotransmission. Materials and Methods:Fluphenazine (0.5, 1, and 3 mg/kg or amisulpride (3, 5, and 10 mg/kg were administered intraperitoneally to male Wistar rats either for one day or 28 consecutive days.Twenty four hours after the last injection of drug or vehicle, neurotensin contents were determined in the mesocorticolimbic and nigrostriatal dopamine regions by radioimmunoassay. In the case of any significant change, the effect of pre-treatment with CB1 receptor antagonist, AM251 was investigated. Results:Chronic, but not acute, treatment with the highest dose of fluphenazine or amisulpride resulted in significant enhancement of neurotensin contents in the prefronatal cortex and nucleus accumbens. Fluphenazine also elevated neurotensin levels in the anterior and posterior caudate nuclei and substantia nigra. Neither amisulpride nor fluphenazine affected neurotensin contents in the amygdala or hippocampus. Pre-treatment with AM251 (3 mg/kg prevented the neuroleptic-induced elevation of neurotensin. AM251 showed no effect by itself. Conclusion:The brain neurotensin under the regulatory action of CB1 receptors is involved in[T1]  the effects of amisulpride and fluphenazine.

  20. Cannabinoid CB1 receptor-interacting proteins: novel targets for central nervous system drug discovery?

    Science.gov (United States)

    Smith, Tricia H; Sim-Selley, Laura J; Selley, Dana E

    2010-06-01

    The main pharmacological effects of marijuana, as well as synthetic and endogenous cannabinoids, are mediated through G-protein-coupled receptors (GPCRs), including CB(1) and CB(2) receptors. The CB(1) receptor is the major cannabinoid receptor in the central nervous system and has gained increasing interest as a target for drug discovery for treatment of nausea, cachexia, obesity, pain, spasticity, neurodegenerative diseases and mood and substance abuse disorders. Evidence has accumulated to suggest that CB(1) receptors, like other GPCRs, interact with and are regulated by several other proteins beyond the established role of heterotrimeric G-proteins. These proteins, which include the GPCR kinases, beta-arrestins, GPCR-associated sorting proteins, factor associated with neutral sphingomyelinase, other GPCRs (heterodimerization) and the novel cannabinoid receptor-interacting proteins: CRIP(1a/b), are thought to play important roles in the regulation of intracellular trafficking, desensitization, down-regulation, signal transduction and constitutive activity of CB(1) receptors. This review examines CB(1) receptor-interacting proteins, including heterotrimeric G-proteins, but with particular emphasis on non-G-protein entities, that might comprise the CB(1) receptosomal complex. The evidence for direct interaction with CB(1) receptors and potential functional roles of these interacting proteins is discussed, as are future directions and challenges in this field with an emphasis on the possibility of eventually targeting these proteins for drug discovery.

  1. Cannabinoid Receptor–Interacting Protein 1a Modulates CB1 Receptor Signaling and Regulation

    OpenAIRE

    Smith, Tricia H.; Blume, Lawrence C.; Straiker, Alex; Cox, Jordan O.; David, Bethany G.; McVoy, Julie R. Secor; Sayers, Katherine W.; Poklis, Justin L.; Abdullah, Rehab A.; Egertová, Michaela; Chen, Ching-Kang; Mackie, Ken; Maurice R. Elphick; Howlett, Allyn C; Selley, Dana E

    2015-01-01

    Cannabinoid CB1 receptors (CB1Rs) mediate the presynaptic effects of endocannabinoids in the central nervous system (CNS) and most behavioral effects of exogenous cannabinoids. Cannabinoid receptor–interacting protein 1a (CRIP1a) binds to the CB1R C-terminus and can attenuate constitutive CB1R-mediated inhibition of Ca2+ channel activity. We now demonstrate cellular colocalization of CRIP1a at neuronal elements in the CNS and show that CRIP1a inhibits both constitutive and agonist-stimulated ...

  2. The diverse CB1 and CB2 receptor pharmacology of three plant cannabinoids: delta9-tetrahydrocannabinol, cannabidiol and delta9-tetrahydrocannabivarin.

    Science.gov (United States)

    Pertwee, R G

    2008-01-01

    Cannabis sativa is the source of a unique set of compounds known collectively as plant cannabinoids or phytocannabinoids. This review focuses on the manner with which three of these compounds, (-)-trans-delta9-tetrahydrocannabinol (delta9-THC), (-)-cannabidiol (CBD) and (-)-trans-delta9-tetrahydrocannabivarin (delta9-THCV), interact with cannabinoid CB1 and CB2 receptors. Delta9-THC, the main psychotropic constituent of cannabis, is a CB1 and CB2 receptor partial agonist and in line with classical pharmacology, the responses it elicits appear to be strongly influenced both by the expression level and signalling efficiency of cannabinoid receptors and by ongoing endogenous cannabinoid release. CBD displays unexpectedly high potency as an antagonist of CB1/CB2 receptor agonists in CB1- and CB2-expressing cells or tissues, the manner with which it interacts with CB2 receptors providing a possible explanation for its ability to inhibit evoked immune cell migration. Delta9-THCV behaves as a potent CB2 receptor partial agonist in vitro. In contrast, it antagonizes cannabinoid receptor agonists in CB1-expressing tissues. This it does with relatively high potency and in a manner that is both tissue and ligand dependent. Delta9-THCV also interacts with CB1 receptors when administered in vivo, behaving either as a CB1 antagonist or, at higher doses, as a CB1 receptor agonist. Brief mention is also made in this review, first of the production by delta9-THC of pharmacodynamic tolerance, second of current knowledge about the extent to which delta9-THC, CBD and delta9-THCV interact with pharmacological targets other than CB1 or CB2 receptors, and third of actual and potential therapeutic applications for each of these cannabinoids.

  3. Deficits in Sensory-Specific Devaluation Task Performance Following Genetic Deletions of Cannabinoid (CB1) Receptor

    Science.gov (United States)

    Crombag, Hans S.; Johnson, Alexander W.; Zimmer, Anne M.; Zimmer, Andreas; Holland, Peter C.

    2010-01-01

    Cannabinoid CB1 receptor is abundantly expressed throughout the CNS and is implicated in numerous physiological and behavioral functions, including appetite and feeding. In the present study, wild-type and CB1 heterozygous and homozygous knockout mice were tested on an instrumental outcome-selective devaluation task to assess changes in acquired…

  4. O-2050 facilitates noradrenaline release and increases the CB1 receptor inverse agonistic effect of rimonabant in the guinea pig hippocampus.

    Science.gov (United States)

    Jergas, Bernd; Schulte, Kirsten; Bindila, Laura; Lutz, Beat; Schlicker, Eberhard

    2014-07-01

    The cannabinoid CB1 receptors on the noradrenergic neurons in guinea pig hippocampal slices show an endogenous endocannabinoid tone. This conclusion is based on rimonabant, the facilitatory effect of which on noradrenaline release might be due to its inverse CB1 receptor agonism and/or the interruption of a tonic inhibition elicited by endocannabinoids. To examine the latter mechanism, a neutral antagonist would be suitable. Therefore, we studied whether O-2050 is a neutral CB1 receptor antagonist in the guinea pig hippocampus and whether it mimics the facilitatory effect of rimonabant. CB1 receptor affinity of O-2050 was quantified in cerebrocortical membranes, using (3)H-rimonabant binding. Its CB1 receptor potency and effect on (3)H-noradrenaline release were determined in superfused hippocampal slices. Its intrinsic activity at CB1 receptors was studied in hippocampal membranes, using (35)S-GTPγS binding. Endocannabinoid levels in hippocampus were determined by liquid chromatography-multiple reaction monitoring. O-2050 was about ten times less potent than rimonabant in its CB1 receptor affinity, potency and facilitatory effect on noradrenaline release. Although not affecting (35)S-GTPγS binding by itself, O-2050 shifted the concentration-response curve of a CB1 receptor agonist to the right but that of rimonabant to the left. Levels of anandamide and 2-arachidonoyl glycerol in guinea pig hippocampus closely resembled those in mouse hippocampus. In conclusion, our results with O-2050 confirm that the CB1 receptors on noradrenergic neurons of the guinea pig hippocampus show an endogenous tone. To differentiate between the two mechanisms leading to an endogenous tone, O-2050 is not superior to rimonabant since O-2050 may increase the inverse agonistic effect of endocannabinoids.

  5. Anandamide drives cell cycle progression through CB1 receptors in a rat model of synchronized liver regeneration.

    Science.gov (United States)

    Pisanti, Simona; Picardi, Paola; Pallottini, Valentina; Martini, Chiara; Petrosino, Stefania; Proto, Maria Chiara; Vitale, Mario; Laezza, Chiara; Gazzerro, Patrizia; Di Marzo, Vincenzo; Bifulco, Maurizio

    2015-12-01

    The endocannabinoid system, through cannabinoid receptor signaling by endocannabinoids, is involved in a wide range of functions and physiopathological conditions. To date, very little is known concerning the role of the endocannabinoids in the control and regulation of cell proliferation. An anti-proliferative action of CB1 signaling blockade in neurogenesis and angiogenesis argues in favor of proliferation-promoting functions of endocannabinoids through CB1 receptors when pro-growth signals are present. Furthermore, liver regeneration, a useful in vivo model of synchronized cell proliferation, is characterized by a peak of anandamide that elicits through CB1 receptor, the expression of critical mitosis genes. The aim of this study was to focus on the timing of endocannabinoid signaling changes during the different phases of the cell cycle, exploiting the rat liver regeneration model following partial hepatectomy, the most useful to study synchronized cell cycle in vivo. Hepatic regeneration led to increased levels of anandamide and endocannabinoid-like molecules oleoylethanolamide (OEA) and palmitoylethanolamide (PEA) in the G1 phase of the cell cycle, with a concomitant increase in CB1 mRNA levels, whose protein expression peaked later during the S phase. Blocking of CB1 receptor with a low dose of the selective antagonist/inverse agonist SR141716 (0.7 mg/kg/dose) affected cell cycle progression reducing the expression of PCNA, and through the inhibition of pERK and pSTAT3 pathways. These results support the notion that the signaling mediated by anandamide through CB1 receptor may be important for the entry and progression of cells into the cell cycle and hence for their proliferation under mitogenic signals.

  6. A2A adenosine receptor antagonism enhances synaptic and motor effects of cocaine via CB1 cannabinoid receptor activation.

    Directory of Open Access Journals (Sweden)

    Alessandro Tozzi

    Full Text Available BACKGROUND: Cocaine increases the level of endogenous dopamine (DA in the striatum by blocking the DA transporter. Endogenous DA modulates glutamatergic inputs to striatal neurons and this modulation influences motor activity. Since D2 DA and A2A-adenosine receptors (A2A-Rs have antagonistic effects on striatal neurons, drugs targeting adenosine receptors such as caffeine-like compounds, could enhance psychomotor stimulant effects of cocaine. In this study, we analyzed the electrophysiological effects of cocaine and A2A-Rs antagonists in striatal slices and the motor effects produced by this pharmacological modulation in rodents. PRINCIPAL FINDINGS: Concomitant administration of cocaine and A2A-Rs antagonists reduced glutamatergic synaptic transmission in striatal spiny neurons while these drugs failed to produce this effect when given in isolation. This inhibitory effect was dependent on the activation of D2-like receptors and the release of endocannabinoids since it was prevented by L-sulpiride and reduced by a CB1 receptor antagonist. Combined application of cocaine and A2A-R antagonists also reduced the firing frequency of striatal cholinergic interneurons suggesting that changes in cholinergic tone might contribute to this synaptic modulation. Finally, A2A-Rs antagonists, in the presence of a sub-threshold dose of cocaine, enhanced locomotion and, in line with the electrophysiological experiments, this enhanced activity required activation of D2-like and CB1 receptors. CONCLUSIONS: The present study provides a possible synaptic mechanism explaining how caffeine-like compounds could enhance psychomotor stimulant effects of cocaine.

  7. Association of cannabis use during adolescence, prefrontal CB1 receptor signaling and schizophrenia

    Directory of Open Access Journals (Sweden)

    Adriana eCaballero

    2012-05-01

    Full Text Available The cannabinoid receptor 1 (CB1R is the G-protein coupled receptor responsible for the majority of the endocannabinoid signaling in the human brain. It is widely distributed in the limbic system, basal ganglia, and cerebellum, which are areas responsible for cognition, memory, and motor control. Because of this widespread distribution, it is not surprising that drugs that co-opt CB1R have expected behavioral outcomes consistent with dysregulated signaling from these areas (e.g. memory loss, cognitive deficits, etc. In the context of this review, we present evidence for the role of CB1R signaling in the prefrontal cortex (PFC, an area involved in executive functions, with emphasis on the developmental regulation of CB1R signaling in the acquisition of mature PFC function. We further hypothesize how alterations of CB1R signaling specifically during adolescent maturation might confer liability to psychiatric disorders.

  8. Cannabinoid CB1 receptor calibrates excitatory synaptic balance in the mouse hippocampus.

    Science.gov (United States)

    Monory, Krisztina; Polack, Martin; Remus, Anita; Lutz, Beat; Korte, Martin

    2015-03-04

    The endocannabinoid system negatively regulates the release of various neurotransmitters in an activity-dependent manner, thereby influencing the excitability of neuronal circuits. In the hippocampus, cannabinoid type 1 (CB1) receptor is present on both GABAergic and glutamatergic axon terminals. CB1 receptor-deficient mice were previously shown to have increased hippocampal long-term potentiation (LTP). In this study, we have investigated the consequences of cell-type-specific deletion of the CB1 receptor on the induction of hippocampal LTP and on CA1 pyramidal cell morphology. Deletion of CB1 receptor in GABAergic neurons in GABA-CB1-KO mice leads to a significantly decreased hippocampal LTP compared with WT controls. Concomitantly, CA1 pyramidal neurons have a significantly reduced dendritic branching both on the apical and on the basal dendrites. Moreover, the average spine density on the apical dendrites of CA1 pyramidal neurons is significantly diminished. In contrast, in mice lacking CB1 receptor in glutamatergic cells (Glu-CB1-KO), hippocampal LTP is significantly enhanced and CA1 pyramidal neurons show an increased branching and an increased spine density in the apical dendritic region. Together, these results indicate that the CB1 receptor signaling system both on inhibitory and excitatory neurons controls functional and structural synaptic plasticity of pyramidal neurons in the hippocampal CA1 region to maintain an appropriate homeostatic state upon neuronal activation. Consequently, if the CB1 receptor is lost in either neuronal population, an allostatic shift will occur leading to a long-term dysregulation of neuronal functions.

  9. Curcumin and hemopressin treatment attenuates cholestasis-induced liver fibrosis in rats: role of CB1 receptors.

    Science.gov (United States)

    El Swefy, Sahar; Hasan, Rehab A; Ibrahim, Amal; Mahmoud, Mona F

    2016-01-01

    Curcumin exerts hepatoprotective effects via poorly defined mechanisms. Recently, some studies suggested that this effect was mediated by antagonizing CB1 receptors in hepatic stellate cells. The current study aimed to investigate whether CB1 antagonist, hemopressin, could potentiate the hepatoprotective effect of curcumin, in comparison with silymarin in bile duct-ligated (BDL) rats. Curcumin and hemopressin each alone and in combination ameliorated biochemical and structural fibrotic injury, and downregulated cyclooxygenase-2 (COX-2) and both mRNA and protein levels of nuclear factor kappa B (NF-κB) in fibrotic liver. In contrast to the previous studies, curcumin alone did not affect the gene expression of cannabinoid receptors. However, the combination of hemopressin and curcumin reduced the expression of CB1 in fibrotic liver. Surprisingly, silymarin upregulated CB2 receptors and downregulated CB1 at mRNA level more than all the administered drugs. Both curcumin and hemopressin each alone decreased lipid peroxidation product, malondialdehyde (MDA), while the combination increased the reduced glutathione content. All the administered drugs increased the hepatic antiapoptotic marker, Bcl2. Our study suggests that hemopressin potentiates the hepatoprotective effect of curcumin on fibrotic liver. We identified a new mechanism of the hepatoprotective effect of silymarin via modulation of cannabinoid receptors in fibrotic liver.

  10. Activation of type 1 cannabinoid receptor (CB1R promotes neurogenesis in murine subventricular zone cell cultures.

    Directory of Open Access Journals (Sweden)

    Sara Xapelli

    Full Text Available The endocannabinoid system has been implicated in the modulation of adult neurogenesis. Here, we describe the effect of type 1 cannabinoid receptor (CB1R activation on self-renewal, proliferation and neuronal differentiation in mouse neonatal subventricular zone (SVZ stem/progenitor cell cultures. Expression of CB1R was detected in SVZ-derived immature cells (Nestin-positive, neurons and astrocytes. Stimulation of the CB1R by (R-(+-Methanandamide (R-m-AEA increased self-renewal of SVZ cells, as assessed by counting the number of secondary neurospheres and the number of Sox2+/+ cell pairs, an effect blocked by Notch pathway inhibition. Moreover, R-m-AEA treatment for 48 h, increased proliferation as assessed by BrdU incorporation assay, an effect mediated by activation of MAPK-ERK and AKT pathways. Surprisingly, stimulation of CB1R by R-m-AEA also promoted neuronal differentiation (without affecting glial differentiation, at 7 days, as shown by counting the number of NeuN-positive neurons in the cultures. Moreover, by monitoring intracellular calcium concentrations ([Ca(2+]i in single cells following KCl and histamine stimuli, a method that allows the functional evaluation of neuronal differentiation, we observed an increase in neuronal-like cells. This proneurogenic effect was blocked when SVZ cells were co-incubated with R-m-AEA and the CB1R antagonist AM 251, for 7 days, thus indicating that this effect involves CB1R activation. In accordance with an effect on neuronal differentiation and maturation, R-m-AEA also increased neurite growth, as evaluated by quantifying and measuring the number of MAP2-positive processes. Taken together, these results demonstrate that CB1R activation induces proliferation, self-renewal and neuronal differentiation from mouse neonatal SVZ cell cultures.

  11. Blockade of cannabinoid CB1 and CB2 receptors does not prevent the antipruritic effect of systemic paracetamol.

    Science.gov (United States)

    Saglam, Gulis; Gunduz, Ozgur; Ulugol, Ahmet

    2014-12-01

    Cannabinoid CB1 receptors have been shown to mediate the antinociceptive, but not the hypothermic, action of the worldwide used analgesic, paracetamol. Since itch and pain sensations share many similarities, the purpose of the present study was to investigate whether blockade of cannabinoid CB1 and CB2 receptors participates in the antipruritic activity of paracetamol in mice. Scratching behavior was induced by intradermal serotonin injection into the rostral part of the back of the mice. After serotonin administration, scratching of the injected site by the hind paws were videotaped and counted for 30 min. Serotonin-induced scratching behavior was attenuated with high-dose paracetamol (300 mg/kg). The CB1 receptor antagonist, AM-251 (1 mg/kg), and the CB2 receptor antagonist, SR-144528 (1 mg/kg), did not alter the anti-scratching behavioral effect of paracetamol. Our results indicate that, in contrast to its antinociceptive action, but similar to its hypothermic effect, cannabinoid receptors are not involved in the antipruritic activity of paracetamol.

  12. Palmitoylethanolamide attenuates PTZ-induced seizures through CB1 and CB2 receptors.

    Science.gov (United States)

    Aghaei, Iraj; Rostampour, Mohammad; Shabani, Mohammad; Naderi, Nima; Motamedi, Fereshteh; Babaei, Parvin; Khakpour-Taleghani, Behrooz

    2015-11-01

    Epilepsy is one of the most common neurologic disorders. Though there are effective medications available to reduce the symptoms of the disease, their side effects have limited their usage. Palmitoylethanolamide (PEA) has been shown to attenuate seizure in different animal models. The objective of the current study was to evaluate the role of CB1 and CB2 receptors in this attenuation. Male wistar rats were used for the current experiment. PTZ was injected to induce chemical kindling in animals. After verification of kindling in animals, treatment was performed with PEA, AM251 and AM630 in different groups. Latency to induce seizure, seizure stages and latency and duration of fifth stage of seizure was recorded for each animal. Injection of PTZ led to seizure in the animals. Pretreatment with PEA increased the latency to initiate seizures and reduced the duration of seizure. Pretreatment with different dosages of AM251 had contrary effects so that at lower doses they increased the seizure in animals but at higher doses led to the attenuation of seizure. AM630 increased seizures in a dose dependent manner. Combination of the antagonists increased the seizure parameters and attenuated the effect of PEA on seizure. PEA attenuated the PTZ-induced seizures and pretreatment with CB1 and CB2 antagonists diminished this effect of PEA, but still PEA was effective, which might be attributed to the contribution of other receptors in PEA anti-epileptic properties. Findings of the current study implied that endocannabinoid signaling pathway might have an important role in the effects of PEA.

  13. CB1 receptor mediates the effects of glucocorticoids on AMPK activity in the hypothalamus.

    Science.gov (United States)

    Scerif, Miski; Füzesi, Tamás; Thomas, Julia D; Kola, Blerina; Grossman, Ashley B; Fekete, Csaba; Korbonits, Márta

    2013-10-01

    AMP-activated protein kinase (AMPK), a regulator of cellular and systemic energy homeostasis, can be influenced by several hormones. Tissue-specific alteration of AMPK activity by glucocorticoids may explain the increase in appetite, the accumulation of lipids in adipose tissues, and the detrimental cardiac effects of Cushing's syndrome. Endocannabinoids are known to mediate the effects of various hormones and to influence AMPK activity. Cannabinoids have central orexigenic and direct peripheral metabolic effects via the cannabinoid receptor type 1 (CB1). In our preliminary experiments, WT mice received implants of a corticosterone-containing pellet to establish a mouse model of Cushing's syndrome. Subsequently, WT and Cb1 (Cnr1)-knockout (CB1-KO) littermates were treated with corticosterone and AMPK activity in the hypothalamus, various adipose tissues, liver and cardiac tissue was measured. Corticosterone-treated CB1-KO mice showed a lack of weight gain and of increase in hypothalamic and hepatic AMPK activity. In adipose tissues, baseline AMPK activity was higher in CB1-KO mice, but a glucocorticoid-induced drop was observed, similar to that observed in WT mice. Cardiac AMPK levels were reduced in CB1-KO mice, but while WT mice showed significantly reduced AMPK activity following glucocorticoid treatment, CB1-KO mice showed a paradoxical increase. Our findings indicate the importance of the CB1 receptor in the central orexigenic effect of glucocorticoid-induced activation of hypothalamic AMPK activity. In the periphery adipose tissues, changes may occur independently of the CB1 receptor, but the receptor appears to alter the responsiveness of the liver and myocardial tissues to glucocorticoids. In conclusion, our data suggest that an intact cannabinoid pathway is required for the full metabolic effects of chronic glucocorticoid excess.

  14. Presence of the cannabinoid receptors, CB1 and CB2, in human omental and subcutaneous adipocytes.

    Science.gov (United States)

    Roche, Régis; Hoareau, Laurence; Bes-Houtmann, Sandrine; Gonthier, Marie-Paule; Laborde, Christine; Baron, Jean-François; Haffaf, Yacine; Cesari, Maya; Festy, Franck

    2006-08-01

    To investigate the expression of the endocannabinoid 1 and 2 receptors by human adipocyte cells of omental and subcutaneous fat tissue, as well as to determine whether these receptors are functional. The expression of CB1 and CB2 receptors on human adipocytes was analyzed by western blotting, immunohistology and immunocytology. We also investigated intracytoplasmic cyclic AMP level modulation following CB1 and CB2 receptor stimulation by an enzymatic immuno assay. All mature adipocytes, from visceral (epiploon) and subcutaneous fat tissue, express CB1 and CB2 on their plasma membranes. We also demonstrate in this study that adipocyte precursors (pre-adipocytes) express CB1 and CB2 on their plasma membranes and that both receptors are functional. Activation of CB1 increases intracytoplasmic cyclic AMP whilst CB2 activation leads to a cyclic AMP decrease. Here we demonstrate, for the first time, that adipocytes of human adipose tissue (mature adipocytes and pre-adipocytes) express functional plasma membrane CB1 and CB2 receptors. Their physiological role on the adipose tissue is not known. However, their major involvement in the physiology of other tissues leads us to suppose that they could play a significant role in the homeostasis of the energy balance and/or in the regulation of adipose tissue inflammation.

  15. CB1 and CB2 receptor expression and promoter methylation in patients with cannabis dependence.

    Science.gov (United States)

    Rotter, Andrea; Bayerlein, Kristina; Hansbauer, Max; Weiland, Judith; Sperling, Wolfgang; Kornhuber, Johannes; Biermann, Teresa

    2013-01-01

    CB1 and CB2 receptors are influenced via exogenous and endogenous cannabinoids. To date, little is known regarding changes in receptor expression and methylation in THC (tetrahydrocannabinol) dependence. Therefore, the CB1 and CB2 receptor mRNA expression levels and promoter methylation status in the peripheral blood cells of 77 subjects (36 with THC dependence, 21 cigarette smokers and 20 nonsmokers) were assessed by quantitative real-time PCR and methylation-specific PCR. There was a significant difference in CB1 receptor expression levels between the three groups (ANOVA, p CB1 receptor mRNA expression levels (Spearman's rho: r = -0.37; p = 0.002). Using a mixed general linear model, it was demonstrated that the CB1 mRNA expression (as the dependent variable) was associated with the satisfaction with life scale (SWLS) (r = 0.101; T = 2.8; p = 0.007), craving (as measured with the VAS; r = -0.023; T = -2.3; p = 0.023) and the WHO-Assist Subscale for Cannabis consumption (r = -0.068; T = -2.4; p = 0.02). CB1 receptor expression levels and methylation status appear to be altered in subjects with THC dependence.

  16. Mapping CB1 cannabinoid receptors with [3H]OMAR in the Flinders rodent model of depression

    DEFF Research Database (Denmark)

    Nahimi, A.; Gjedde, A.; Wong, D. F.

    2012-01-01

    ). In these rats, CB1 receptor autoradiography in postmortem tissue was carried out by incubating 20 mM thick sagital sections in the presence of the CB1 receptor antagonist [3H] OMAR (method adapted from Mato & Pazos 2004, with small modifications). Non-specific binding was determined on adjacent sections...... in the presence of [3H]OMAR and the CB receptor agonist CP55,940. Results: Eighteen regions of interest were analyzed on the autoradiogram. The highest binding (in units of pmol/g(plus or minus)SD) was found in the hippocampus (105(plus or minus)21 in FSL and 105(plus or minus)16 in FRL), striatum (69(plus...

  17. Activation of cannabinoid CB1 receptors in the ventral hippocampus improved stress-induced amnesia in rat.

    Science.gov (United States)

    Mohammadmirzaei, Negin; Rezayof, Ameneh; Ghasemzadeh, Zahra

    2016-09-01

    The ventral hippocampus (VH) has a high distribution of cannabinoid CB1 receptors which are important in modulating stress responses. Stress exposure activates the hypothalamic-pituitary-adrenal axis (HPA) which can impact hippocampal formation to change hippocampus-based memories. The purpose of the present study was to determine the possible role of the VH cannabinoid CB1 receptors in stress-induced amnesia using a step-through passive avoidance procedure in male Wistar rats. In order to induce acute stress, the animals were placed on an elevated platform for different time periods (10, 20 and 30min). Our results indicated that post-training 20 and 30min exposure to stress, but not 10min, induced amnesia. Post-training microinjection of a cannabinoid CB1 receptor agonist, arachydonilcyclopropylamide (ACPA; 2.5-7.5ng/rat) into the VH (intra-VH) induced amnesia. Interestingly, post-training intra-VH microinjection of the same doses of ACPA improved stress-induced amnesia. On the other hand, post-training intra-VH microinjection of a selective CB1 receptor antagonist, AM-251 (20-50ng/rat) with exposure to an ineffective stress (10min) potentiated the effect of stress on memory consolidation and induced amnesia. It should be noted that post-training intra-VH microinjection of the same doses of AM-251 alone had no effect on memory consolidation. Our results revealed that post-training intra-VH microinjection of AM-251, prior to ACPA microinjection, inhibited the reversal effect of ACPA on acute elevated platform stress. Taken together, it can be concluded that exposure to post-training inescapable stress impaired memory consolidation. The impairing effects of stress on memory retrieval may be mediated by the VH cannabinoid CB1 receptors.

  18. Rapid CB1 cannabinoid receptor desensitization defines the time course of ERK1/2 MAP kinase signaling.

    Science.gov (United States)

    Daigle, Tanya L; Kearn, Christopher S; Mackie, Ken

    2008-01-01

    Molecular mechanisms regulating the development of physiological and behavioral tolerance to cannabinoids are not well understood. Two cellular correlates implicated in the development and maintenance of tolerance are CB(1) cannabinoid receptor internalization and uncoupling of receptor signal transduction. Both processes have been proposed as mediators of tolerance because of observations that chronic Delta(9)-tetrahydrocannabinol (THC) treatment causes both region-specific decreases in CB(1) receptors and G-protein coupling in the brain. To determine the balance of these two processes in regulating CB(1) receptor signaling during sustained receptor stimulation, we evaluated the parameters affecting ERK1/2 MAP kinase activity in HEK293 cells stably expressing CB(1) receptors. CB(1) receptor stimulation by the potent CB(1) receptor agonist, CP 55,940 transiently activated ERK1/2. To determine if CB(1) receptor desensitization or internalization was responsible for the transient nature of ERK1/2 activation, we evaluated ERK1/2 phosphorylation in HEK293 cells expressing a desensitization-deficient CB(1) receptor (S426A/S430A CB(1)). Here, the duration of S426A/S430A CB(1) receptor-mediated activation of ERK1/2 was markedly prolonged relative to wild-type receptors, and was dynamically reversed by SR141716A. Interestingly, the S426A/S430A CB(1) receptor was still able to recruit betaarrestin-2, a key mediator of receptor desensitization, to the cell surface following agonist activation. In contrast to a central role for desensitization, pharmacological and genetic approaches suggested CB(1) receptor internalization is dispensable in the transient activation of ERK1/2. This study indicates that the duration of ERK1/2 activation by CB(1) receptors is regulated by receptor desensitization and underscores the importance of G-protein uncoupling in the regulation of CB(1) receptor signaling.

  19. Astroglial CB1 cannabinoid receptors regulate leptin signaling in mouse brain astrocytes.

    Science.gov (United States)

    Bosier, Barbara; Bellocchio, Luigi; Metna-Laurent, Mathilde; Soria-Gomez, Edgar; Matias, Isabelle; Hebert-Chatelain, Etienne; Cannich, Astrid; Maitre, Marlène; Leste-Lasserre, Thierry; Cardinal, Pierre; Mendizabal-Zubiaga, Juan; Canduela, Miren Josune; Reguero, Leire; Hermans, Emmanuel; Grandes, Pedro; Cota, Daniela; Marsicano, Giovanni

    2013-01-01

    Type-1 cannabinoid (CB1) and leptin (ObR) receptors regulate metabolic and astroglial functions, but the potential links between the two systems in astrocytes were not investigated so far. Genetic and pharmacological manipulations of CB1 receptor expression and activity in cultured cortical and hypothalamic astrocytes demonstrated that cannabinoid signaling controls the levels of ObR expression. Lack of CB1 receptors also markedly impaired leptin-mediated activation of signal transducers and activators of transcription 3 and 5 (STAT3 and STAT5) in astrocytes. In particular, CB1 deletion determined a basal overactivation of STAT5, thereby leading to the downregulation of ObR expression, and leptin failed to regulate STAT5-dependent glycogen storage in the absence of CB1 receptors. These results show that CB1 receptors directly interfere with leptin signaling and its ability to regulate glycogen storage, thereby representing a novel mechanism linking endocannabinoid and leptin signaling in the regulation of brain energy storage and neuronal functions.

  20. Computational Prediction and Biochemical Analyses of New Inverse Agonists for the CB1 Receptor.

    Science.gov (United States)

    Scott, Caitlin E; Ahn, Kwang H; Graf, Steven T; Goddard, William A; Kendall, Debra A; Abrol, Ravinder

    2016-01-25

    Human cannabinoid type 1 (CB1) G-protein coupled receptor is a potential therapeutic target for obesity. The previously predicted and experimentally validated ensemble of ligand-free conformations of CB1 [Scott, C. E. et al. Protein Sci. 2013 , 22 , 101 - 113 ; Ahn, K. H. et al. Proteins 2013 , 81 , 1304 - 1317] are used here to predict the binding sites for known CB1-selective inverse agonists including rimonabant and its seven known derivatives. This binding pocket, which differs significantly from previously published models, is used to identify 16 novel compounds expected to be CB1 inverse agonists by exploiting potential new interactions. We show experimentally that two of these compounds exhibit inverse agonist properties including inhibition of basal and agonist-induced G-protein coupling activity, as well as an enhanced level of CB1 cell surface localization. This demonstrates the utility of using the predicted binding sites for an ensemble of CB1 receptor structures for designing new CB1 inverse agonists.

  1. Modulation of Network Oscillatory Activity and GABAergic Synaptic Transmission by CB1 Cannabinoid Receptors in the Rat Medial Entorhinal Cortex

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    Nicola H. Morgan

    2008-01-01

    Full Text Available Cannabinoids modulate inhibitory GABAergic neurotransmission in many brain regions. Within the temporal lobe, cannabinoid receptors are highly expressed, and are located presynaptically at inhibitory terminals. Here, we have explored the role of type-1 cannabinoid receptors (CB1Rs at the level of inhibitory synaptic currents and field-recorded network oscillations. We report that arachidonylcyclopropylamide (ACPA; 10 M, an agonist at CB1R, inhibits GABAergic synaptic transmission onto both superficial and deep medial entorhinal (mEC neurones, but this has little effect on network oscillations in beta/gamma frequency bands. By contrast, the CB1R antagonist/inverse agonist LY320135 (500 nM, increased GABAergic synaptic activity and beta/gamma oscillatory activity in superficial mEC, was suppressed, whilst that in deep mEC was enhanced. These data indicate that cannabinoid-mediated effects on inhibitory synaptic activity may be constitutively active in vitro, and that modulation of CB1R activation using inverse agonists unmasks complex effects of CBR function on network activity.

  2. Intra-accumbal CB1 receptor blockade reduced extinction and reinstatement of morphine.

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    Khaleghzadeh-Ahangar, Hossein; Haghparast, Abbas

    2015-10-01

    The limbic dopaminergic reward system is the main target of morphine-like drugs which begins from the ventral tegmental area (VTA) and sends its dopaminergic projections to the nucleus accumbens (NAc), amygdala, hippocampus and prefrontal cortex. Cannabinoid receptors exist in afferent neurons from these areas to the NAc and can modulate glutamate synaptic transmission in the NAc. Cannabinoids can interact with the opiate system in reward-related behaviors; nevertheless these systems' interaction in extinction duration and reinstatement has not been shown. In the present study, the effects of bilateral intra-accumbal administration of AM251, a CB1 receptor antagonist, on the duration of the extinction phase and reinstatement to morphine were investigated by conditioned place preference (CPP) paradigm. Forty eight adult male albino Wistar rats were used. Bilateral intra-accumbal administration of AM251 (15, 45 and 90μM/0.5μl DMSO per side) was performed. Subcutaneous administration of morphine (5mg/kg) in three consecutive days was used to induce CPP. The results showed that administration of the maximal dose of AM251 during the extinction period significantly reduces duration of extinction and reinstatement to morphine. Administration of the middle dose during the extinction period significantly attenuated reinstatement to morphine. A single microinjection of the middle dose just before the reinstatement phase significantly attenuated reinstatement to morphine only, while bilateral intra-accumbal administration of neither the lowest dose nor the vehicle (DMSO) had any effects. These results for the first time indicated that CB1 receptors within the NAc are involved in the maintenance of morphine rewarding properties, and morphine seeking behaviors in extinguished morphine-induced CPP rats.

  3. Beneficial effects of cannabinoids (CB) in a murine model of allergen-induced airway inflammation: role of CB1/CB2 receptors.

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    Braun, Andrea; Engel, Tabea; Aguilar-Pimentel, Juan Antonio; Zimmer, Andreas; Jakob, Thilo; Behrendt, Heidrun; Mempel, Martin

    2011-04-01

    The endocannabinoid system (ECS) consists of two cannabinoid (CB) receptors, namely CB(1) and CB(2) receptor, and their endogenous (endocannabinoids) and exogenous (cannabinoids, e.g. delta-9-tetrahydrocannabinol (THC)) ligands which bind to these receptors. Based on studies suggesting a role of THC and the ECS in inflammation, the objective of this study was to examine their involvement in type I hypersensitivity using a murine model of allergic airway inflammation. THC treatment of C57BL/6 wildtype mice dramatically reduced airway inflammation as determined by significantly reduced total cell counts in bronchoalveolar lavage (BAL). These effects were greatest when mice were treated during both, the sensitization and the challenge phase. Furthermore, systemic immune responses were significantly suppressed in mice which received THC during sensitization phase. To investigate a role of CB(1/2) receptors in this setting, we used pharmacological blockade of CB(1) and/or CB(2) receptors by the selective antagonists and moreover CB(1)/CB(2) receptor double-knockout mice (CB(1)(-/-)/CB(2)(-/-)) and found neither significant changes in the cell patterns in BAL nor in immunoglobulin levels as compared to wildtype mice. Our results indicate that the activation of the ECS by applying the agonist THC is involved in the development of type I allergies. However, CB(1)/CB(2) receptor-independent signalling seems likely in the observed results.

  4. Pharmacological activation of CB1 receptor modulates long term potentiation by interfering with protein synthesis.

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    Navakkode, Sheeja; Korte, Martin

    2014-04-01

    Cognitive impairment is one of the most important side effects associated with cannabis drug abuse, as well as the serious issue concerning the therapeutic use of cannabinoids. Cognitive impairments and neuropsychiatric symptoms are caused by early synaptic dysfunctions, such as loss of synaptic connections in different brain structures including the hippocampus, a region that is believed to play an important role in certain forms of learning and memory. We report here that metaplastic priming of synapses with a cannabinoid type 1 receptor (CB1 receptor) agonist, WIN55,212-2 (WIN55), significantly impaired long-term potentiation in the apical dendrites of CA1 pyramidal neurons. Interestingly, the CB1 receptor exerts its effect by altering the balance of protein synthesis machinery towards higher protein production. Therefore the activation of CB1 receptor, prior to strong tetanization, increased the propensity to produce new proteins. In addition, WIN55 priming resulted in the expression of late-LTP in a synaptic input that would have normally expressed early-LTP, thus confirming that WIN55 priming of LTP induces new synthesis of plasticity-related proteins. Furthermore, in addition to the effects on protein translation, WIN55 also induced synaptic deficits due to the ability of CB1 receptors to inhibit the release of acetylcholine, mediated by both muscarinic and nicotinic acetylcholine receptors. Taken together this supports the notion that the modulation of cholinergic activity by CB1 receptor activation is one mechanism that regulates the synthesis of plasticity-related proteins.

  5. CB1 cannabinoid receptor enrichment in the ependymal region of the adult human spinal cord.

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    Paniagua-Torija, Beatriz; Arevalo-Martin, Angel; Ferrer, Isidro; Molina-Holgado, Eduardo; Garcia-Ovejero, Daniel

    2015-12-04

    Cannabinoids are involved in the regulation of neural stem cell biology and their receptors are expressed in the neurogenic niches of adult rodents. In the spinal cord of rats and mice, neural stem cells can be found in the ependymal region, surrounding the central canal, but there is evidence that this region is largely different in adult humans: lacks a patent canal and presents perivascular pseudorosettes, typically found in low grade ependymomas. Using Laser Capture Microdissection, Taqman gene expression assays and immunohistochemistry, we have studied the expression of endocannabinoid system components (receptors and enzymes) at the human spinal cord ependymal region. We observe that ependymal region is enriched in CB1 cannabinoid receptor, due to high CB1 expression in GFAP+ astrocytic domains. However, in human spinal cord levels that retain central canal patency we found ependymal cells with high CB1 expression, equivalent to the CB1(HIGH) cell subpopulation described in rodents. Our results support the existence of ependymal CB1(HIGH) cells across species, and may encourage further studies on this subpopulation, although only in cases when central canal is patent. In the adult human ependyma, which usually shows central canal absence, CB1 may play a different role by modulating astrocyte functions.

  6. Effects of the CB1R agonist WIN-55,212-2 and the CB1R antagonists SR-141716 and AM-1387: open-field examination in rats.

    Science.gov (United States)

    Järbe, T U C; Ross, T; DiPatrizio, N V; Pandarinathan, L; Makriyannis, A

    2006-09-01

    This study examined the open-field (O-F) effects in rats of the cannabinoid 1 receptor (CB1R) agonist WIN-55,212-2 (WIN; 1 to 5.6 mg/kg) and its interaction with the CB1R antagonist/inverse agonist SR-141716 (1 to 5.6 mg/kg). Additionally, separate studies examined the O-F effects of SR-141716 (1 to 10 mg/kg) and a newly synthesized CB1R selective antagonist/inverse agonist AM-1387 (3 and 10 mg/kg) when these ligands were administered alone. Both antagonists are characterized in vitro by decreased of GTPgammaS binding and increased cAMP accumulation (inverse agonism). WIN dose dependently reduced ambulation (horizontal activity) and rearing (vertical activity); SR-141716 completely (WIN 3 mg/kg) or partially (WIN 5.6 mg/kg) normalized these behaviors. WIN alone resulted in circling and in an increased latency to leave the start area of the O-F, effects blocked by all doses of SR-141716. Both the increased scratching and grooming, associated with SR-141716 administration, were attenuated but not abolished by WIN. SR-141716 alone tended to reduce ambulation (significant at 10 mg/kg) and rearing (non-significant), had no effect on latency, and increased scratching and grooming (both frequency and duration), at doses of 3 mg/kg and up. At the doses examined, AM-1387 had no effect on ambulation, rearing, latency but significantly increased scratching (10 mg/kg); there was also a trend for increased grooming (both frequency and duration). The O-F profile of WIN suggests more similarity with the effects of THC rather than methanandamide (and presumably also anandamide). Intrinsic activity (scratching and grooming) by SR-141716 was re-affirmed and seemed to be associated with administration of AM-1387 as well. AM-1387 was less potent than SR-141716.

  7. WIN 55212-2 impairs contextual fear conditioning through the activation of CB1 cannabinoid receptors.

    Science.gov (United States)

    Pamplona, Fabrício Alano; Takahashi, Reinaldo Naoto

    The memory deficits induced by cannabinoid agonists have been found in several behavioral paradigms. Nevertheless, there is evidence that not all types of memory are impaired after cannabinoid administration. The aim of this study was to investigate whether the cannabinoid agonist WIN 55212-2 (WIN) is able to influence the acquisition of fear conditioning using tone and contextual versions. For tone-fear conditioning, male Wistar rats were placed in the conditioning chamber and after 3 min, a sound (CS) was presented for 10s that terminated with a 1-s electric footshock (1.5 mA). For contextual-fear conditioning, a similar procedure was used but no sound was presented. Twenty-four hours after, the animals were re-exposed to the respective CS (tone or conditioning chamber) and the freezing behavior was registered. A subsequent experiment investigated a possible state-dependent effect of WIN by administering WIN or control solution 30 min before conditioning and before testing. WIN (2.5 and 5.0 mg/kg) administered i.p. 30 min before impaired contextual fear conditioning but did not modify the freezing behavior elicited by tone presentation. These animals did not show any state-dependent effects of WIN. Further, the impaired contextual conditioning was prevented by preadministration of SR141716A (1.0 mg/kg, i.p.) or SR147778 (1.0 mg/kg, i.p.), selective cannabinoid CB1 receptor antagonists. The present findings highlight that cannabinoid agonists effects are selective for the hippocampus-dependent aversive memories in rats. This effect appears to be related to the activation of CB1 cannabinoid receptors and confirms that cannabinoids might provide a novel approach for the treatment of unpleasant memories.

  8. Negative Regulation of Leptin-induced Reactive Oxygen Species (ROS) Formation by Cannabinoid CB1 Receptor Activation in Hypothalamic Neurons.

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    Palomba, Letizia; Silvestri, Cristoforo; Imperatore, Roberta; Morello, Giovanna; Piscitelli, Fabiana; Martella, Andrea; Cristino, Luigia; Di Marzo, Vincenzo

    2015-05-29

    The adipocyte-derived, anorectic hormone leptin was recently shown to owe part of its regulatory effects on appetite-regulating hypothalamic neuropeptides to the elevation of reactive oxygen species (ROS) levels in arcuate nucleus (ARC) neurons. Leptin is also known to exert a negative regulation on hypothalamic endocannabinoid levels and hence on cannabinoid CB1 receptor activity. Here we investigated the possibility of a negative regulation by CB1 receptors of leptin-mediated ROS formation in the ARC. Through pharmacological and molecular biology experiments we report data showing that leptin-induced ROS accumulation is 1) blunted by arachidonyl-2'-chloroethylamide (ACEA) in a CB1-dependent manner in both the mouse hypothalamic cell line mHypoE-N41 and ARC neuron primary cultures, 2) likewise blocked by a peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist, troglitazone, in a manner inhibited by T0070907, a PPAR-γ antagonist that also inhibited the ACEA effect on leptin, 3) blunted under conditions of increased endocannabinoid tone due to either pharmacological or genetic inhibition of endocannabinoid degradation in mHypoE-N41 and primary ARC neuronal cultures from MAGL(-/-) mice, respectively, and 4) associated with reduction of both PPAR-γ and catalase activity, which are reversed by both ACEA and troglitazone. We conclude that CB1 activation reverses leptin-induced ROS formation and hence possibly some of the ROS-mediated effects of the hormone by preventing PPAR-γ inhibition by leptin, with subsequent increase of catalase activity. This mechanism might underlie in part CB1 orexigenic actions under physiopathological conditions accompanied by elevated hypothalamic endocannabinoid levels.

  9. Expression of the cannabinoid receptor CB1 in distinct neuronal subpopulations in the adult mouse forebrain.

    Science.gov (United States)

    Marsicano, G; Lutz, B

    1999-12-01

    Cannabinoids can modulate motor behaviour, learning and memory, cognition and pain perception. These effects correlate with the expression of the cannabinoid receptor 1 (CB1) and with the presence of endogenous cannabinoids in the brain. In trying to obtain further insights into the mechanisms underlying the modulatory effects of cannabinoids, CB1-positive neurons were determined in the murine forebrain at a single cell resolution. We performed a double in situ hybridization study to detect mRNA of CB1 in combination with mRNA of glutamic acid decarboxylase 65k, neuropeptide cholecystokinin (CCK), parvalbumin, calretinin and calbindin D28k, respectively. Our results revealed that CB1-expressing cells can be divided into distinct neuronal subpopulations. There is a clear distinction between neurons containing CB1 mRNA either at high levels or low levels. The majority of high CB1-expressing cells are GABAergic (gamma-aminobutyric acid) neurons belonging mainly to the cholecystokinin-positive and parvalbumin-negative type of interneurons (basket cells) and, to a lower extent, to the calbindin D28k-positive mid-proximal dendritic inhibitory interneurons. Only a fraction of low CB1-expressing cells is GABAergic. In the hippocampus, amygdala and entorhinal cortex area, CB1 mRNA is present at low but significant levels in many non-GABAergic cells that can be considered as projecting principal neurons. Thus, a complex mechanism appears to underlie the modulatory effects of cannabinoids. They might act on principal glutamatergic circuits as well as modulate local GABAergic inhibitory circuits. CB1 is very highly coexpressed with CCK. It is known that cannabinoids and CCK often have opposite effects on behaviour and physiology. Therefore, we suggest that a putative cross-talk between cannabinoids and CCK might exist and will be relevant to better understanding of physiology and pharmacology of the cannabinoid system.

  10. Anti-inflammatory lipoxin A4 is an endogenous allosteric enhancer of CB1 cannabinoid receptor.

    Science.gov (United States)

    Pamplona, Fabricio A; Ferreira, Juliano; Menezes de Lima, Octávio; Duarte, Filipe Silveira; Bento, Allisson Freire; Forner, Stefânia; Villarinho, Jardel G; Bellocchio, Luigi; Bellochio, Luigi; Wotjak, Carsten T; Lerner, Raissa; Monory, Krisztina; Lutz, Beat; Canetti, Claudio; Matias, Isabelle; Calixto, João Batista; Marsicano, Giovanni; Guimarães, Marilia Z P; Takahashi, Reinaldo N

    2012-12-18

    Allosteric modulation of G-protein-coupled receptors represents a key goal of current pharmacology. In particular, endogenous allosteric modulators might represent important targets of interventions aimed at maximizing therapeutic efficacy and reducing side effects of drugs. Here we show that the anti-inflammatory lipid lipoxin A(4) is an endogenous allosteric enhancer of the CB(1) cannabinoid receptor. Lipoxin A(4) was detected in brain tissues, did not compete for the orthosteric binding site of the CB(1) receptor (vs. (3)H-SR141716A), and did not alter endocannabinoid metabolism (as opposed to URB597 and MAFP), but it enhanced affinity of anandamide at the CB1 receptor, thereby potentiating the effects of this endocannabinoid both in vitro and in vivo. In addition, lipoxin A(4) displayed a CB(1) receptor-dependent protective effect against β-amyloid (1-40)-induced spatial memory impairment in mice. The discovery of lipoxins as a class of endogenous allosteric modulators of CB(1) receptors may foster the therapeutic exploitation of the endocannabinoid system, in particular for the treatment of neurodegenerative disorders.

  11. Physiological impact of CB1 receptor expression by hippocampal GABAergic interneurons.

    Science.gov (United States)

    Albayram, Önder; Passlick, Stefan; Bilkei-Gorzo, Andras; Zimmer, Andreas; Steinhäuser, Christian

    2016-04-01

    A subset of hippocampal GABAergic neurons, which are cholecystokinin-positive, highly express cannabinoid type 1 (CB1) receptors. Activation of these receptors inhibits GABA release and thereby limits inhibitory control. While genetic deletion of CB1 receptors from GABAergic neurons led to behavioural alterations and neuroinflammatory reactions, it remained unclear whether these changes in the knockout animals were a direct consequence of the enhanced transmitter release or reflected developmental deficits. The hippocampus is vital for the generation of spatial, declarative and working memory. Here, we addressed the question how CB1 receptors in GABAergic neurons influence hippocampal function. Patch clamp and field potential recordings in mice devoid of CB1 receptors in GABAergic neurons revealed an enhanced frequency and faster kinetics of spontaneous inhibitory postsynaptic currents in CA1 pyramidal neurons while tonic inhibition, paired-pulse facilitation and long-term potentiation in the hippocampus were not affected. Evaluation of cognitive functions demonstrated impaired acquisition of spatial memory and deficits in novel object recognition and partner recognition in the knockout mice, while working memory and spatial memory remained intact. The density of GABAergic neurons was also similar in knockout mice and their littermates, which argues against global deficits in hippocampal development. Together, these results suggest that CB1 receptors in GABAergic neurons influence specific aspects of neuronal excitability and hippocampal learning.

  12. Cannabinoid receptors, CB1 and CB2, as novel targets for inhibition of non-small cell lung cancer growth and metastasis.

    Science.gov (United States)

    Preet, Anju; Qamri, Zahida; Nasser, Mohd W; Prasad, Anil; Shilo, Konstantin; Zou, Xianghong; Groopman, Jerome E; Ganju, Ramesh K

    2011-01-01

    Non-small cell lung cancer (NSCLC) is the leading cause of cancer deaths worldwide; however, only limited therapeutic treatments are available. Hence, we investigated the role of cannabinoid receptors, CB1 and CB2, as novel therapeutic targets against NSCLC. We observed expression of CB1 (24%) and CB2 (55%) in NSCLC patients. Furthermore, we have shown that the treatment of NSCLC cell lines (A549 and SW-1573) with CB1/CB2- and CB2-specific agonists Win55,212-2 and JWH-015, respectively, significantly attenuated random as well as growth factor-directed in vitro chemotaxis and chemoinvasion in these cells. We also observed significant reduction in focal adhesion complex, which plays an important role in migration, upon treatment with both JWH-015 and Win55,212-2. In addition, pretreatment with CB1/CB2 selective antagonists, AM251 and AM630, prior to JWH-015 and Win55,212-2 treatments, attenuated the agonist-mediated inhibition of in vitro chemotaxis and chemoinvasion. In addition, both CB1 and CB2 agonists Win55,212-2 and JWH-133, respectively, significantly inhibited in vivo tumor growth and lung metastasis (∼50%). These effects were receptor mediated, as pretreatment with CB1/CB2 antagonists abrogated CB1/CB2 agonist-mediated effects on tumor growth and metastasis. Reduced proliferation and vascularization, along with increased apoptosis, were observed in tumors obtained from animals treated with JWH-133 and Win55,212-2. Upon further elucidation into the molecular mechanism, we observed that both CB1 and CB2 agonists inhibited phosphorylation of AKT, a key signaling molecule controlling cell survival, migration, and apoptosis, and reduced matrix metalloproteinase 9 expression and activity. These results suggest that CB1 and CB2 could be used as novel therapeutic targets against NSCLC.

  13. The cannabinoid CB1 receptor and mTORC1 signalling pathways interact to modulate glucose homeostasis in mice.

    Science.gov (United States)

    Bermudez-Silva, Francisco J; Romero-Zerbo, Silvana Y; Haissaguerre, Magalie; Ruz-Maldonado, Inmaculada; Lhamyani, Said; El Bekay, Rajaa; Tabarin, Antoine; Marsicano, Giovanni; Cota, Daniela

    2016-01-01

    The endocannabinoid system (ECS) is an intercellular signalling mechanism that is present in the islets of Langerhans and plays a role in the modulation of insulin secretion and expansion of the β-cell mass. The downstream signalling pathways mediating these effects are poorly understood. Mammalian target of rapamycin complex 1 (mTORC1) signalling is a key intracellular pathway involved in energy homeostasis and is known to importantly affect the physiology of pancreatic islets. We investigated the possible relationship between cannabinoid type 1 (CB1) receptor signalling and the mTORC1 pathway in the endocrine pancreas of mice by using pharmacological analysis as well as mice genetically lacking the CB1 receptor or the downstream target of mTORC1, the kinase p70S6K1. In vitro static secretion experiments on islets, western blotting, and in vivo glucose and insulin tolerance tests were performed. The CB1 receptor antagonist rimonabant decreased glucose-stimulated insulin secretion (GSIS) at 0.1 µM while increasing phosphorylation of p70S6K1 and ribosomal protein S6 (rpS6) within the islets. Specific pharmacological blockade of mTORC1 by 3 nM rapamycin, as well as genetic deletion of p70S6K1, impaired the CB1-antagonist-mediated decrease in GSIS. In vivo experiments showed that 3 mg/kg body weight rimonabant decreased insulin levels and induced glucose intolerance in lean mice without altering peripheral insulin sensitivity; this effect was prevented by peripheral administration of low doses of rapamycin (0.1 mg/kg body weight), which increased insulin sensitivity. These findings suggest a functional interaction between the ECS and the mTORC1 pathway within the endocrine pancreas and at the whole-organism level, which could have implications for the development of new therapeutic approaches for pancreatic β-cell diseases.

  14. CB1 and CB2 cannabinoid receptor expression during development and in epileptogenic developmental pathologies.

    Science.gov (United States)

    Zurolo, E; Iyer, A M; Spliet, W G M; Van Rijen, P C; Troost, D; Gorter, J A; Aronica, E

    2010-09-29

    Recent data support the involvement of the endocannabinoid signaling in early brain development, as well as a key role of cannabinoid receptors (CBR) in pathological conditions associated with unbalanced neuronal excitability and inflammation. Using immunocytochemistry, we explored the expression and cellular pattern of CBR 1 and 2 (CB1 and CB2) during prenatal human cortical development, as well as in focal malformations of cortical development associated with intractable epilepsy (focal cortical dysplasia; cortical tubers in patients with the tuberous sclerosis complex and glioneuronal tumors). Strong CB1 immunoreactivity was detected in the cortical plate in developing human brain from the earliest stages tested (gestational week 9) and it persisted throughout prenatal development. Both cannabinoid receptors were not detected in neural progenitor cells located in the ventricular zone. Only CB1 was expressed in the subventricular zone and in Cajal-Retzius cells in the molecular zone of the developing neocortex. CB2 was detected in cells of the microglia/macrophage lineage during development. In malformations of cortical development, prominent CB1 expression was demonstrated in dysplastic neurons. Both CBR were detected in balloon/giant cells, but CB2 appeared to be more frequently expressed than CB1 in these cell types. Reactive astrocytes were mainly stained with CB1, whereas cells of the microglia/macrophage lineage were stained with CB2. These findings confirm the early expression pattern of cannabinoid receptors in the developing human brain, suggesting a function for CB1 in the early stages of corticogenesis. The expression patterns in malformations of cortical development highlight the role of cannabinoid receptors as mediators of the endocannabinoid signaling and as potential pharmacological targets to modulate neuronal and glial cell function in epileptogenic developmental pathologies.

  15. Human CB1 Receptor Isoforms, present in Hepatocytes and β-cells, are Involved in Regulating Metabolism.

    Science.gov (United States)

    González-Mariscal, Isabel; Krzysik-Walker, Susan M; Doyle, Máire E; Liu, Qing-Rong; Cimbro, Raffaello; Santa-Cruz Calvo, Sara; Ghosh, Soumita; Cieśla, Łukasz; Moaddel, Ruin; Carlson, Olga D; Witek, Rafal P; O'Connell, Jennifer F; Egan, Josephine M

    2016-09-19

    Therapeutics aimed at blocking the cannabinoid 1 (CB1) receptor for treatment of obesity resulted in significant improvements in liver function, glucose uptake and pancreatic β-cell function independent of weight loss or CB1 receptor blockade in the brain, suggesting that peripherally-acting only CB1 receptor blockers may be useful therapeutic agents. Neuropsychiatric side effects and lack of tissue specificity precluded clinical use of first-generation, centrally acting CB1 receptor blockers. In this study we specifically analyzed the potential relevance to diabetes of human CB1 receptor isoforms in extraneural tissues involved in glucose metabolism. We identified an isoform of the human CB1 receptor (CB1b) that is highly expressed in β-cells and hepatocytes but not in the brain. Importantly, CB1b shows stronger affinity for the inverse agonist JD-5037 than for rimonabant compared to CB1 full length. Most relevant to the field, CB1b is a potent regulator of adenylyl cyclase activity in peripheral metabolic tissues. CB1b blockade by JD-5037 results in stronger adenylyl cyclase activation compared to rimonabant and it is a better enhancer of insulin secretion in β-cells. We propose this isoform as a principal pharmacological target for the treatment of metabolic disorders involving glucose metabolism.

  16. Human CB1 Receptor Isoforms, present in Hepatocytes and β-cells, are Involved in Regulating Metabolism

    Science.gov (United States)

    González-Mariscal, Isabel; Krzysik-Walker, Susan M.; Doyle, Máire E.; Liu, Qing-Rong; Cimbro, Raffaello; Santa-Cruz Calvo, Sara; Ghosh, Soumita; Cieśla, Łukasz; Moaddel, Ruin; Carlson, Olga D.; Witek, Rafal P.; O’Connell, Jennifer F.; Egan, Josephine M.

    2016-01-01

    Therapeutics aimed at blocking the cannabinoid 1 (CB1) receptor for treatment of obesity resulted in significant improvements in liver function, glucose uptake and pancreatic β-cell function independent of weight loss or CB1 receptor blockade in the brain, suggesting that peripherally-acting only CB1 receptor blockers may be useful therapeutic agents. Neuropsychiatric side effects and lack of tissue specificity precluded clinical use of first-generation, centrally acting CB1 receptor blockers. In this study we specifically analyzed the potential relevance to diabetes of human CB1 receptor isoforms in extraneural tissues involved in glucose metabolism. We identified an isoform of the human CB1 receptor (CB1b) that is highly expressed in β-cells and hepatocytes but not in the brain. Importantly, CB1b shows stronger affinity for the inverse agonist JD-5037 than for rimonabant compared to CB1 full length. Most relevant to the field, CB1b is a potent regulator of adenylyl cyclase activity in peripheral metabolic tissues. CB1b blockade by JD-5037 results in stronger adenylyl cyclase activation compared to rimonabant and it is a better enhancer of insulin secretion in β-cells. We propose this isoform as a principal pharmacological target for the treatment of metabolic disorders involving glucose metabolism. PMID:27641999

  17. Stimulation of cannabinoid CB1 receptors prevents nerve-mediated airway hyperreactivity in NGF-induced inflammation in mouse airways.

    Science.gov (United States)

    Bozkurt, Turgut Emrah; Larsson, Olivia; Adner, Mikael

    2016-04-05

    Cannabinoids are known to inhibit neuronal activity and have significant immunomodulatory effects which suggest a role in inflammatory airway diseases. In the present study, we tested the hypothesis that cannabinoids have both acute and chronic modulatory effects on nerve-mediated contractions in NGF-induced airway inflammation. Contractions induced by electrical field stimulation (EFS) were examined in tracheal segments isolated from male BALB/c mice. Tissues were both used fresh or after four days of culture with NGF to induce airway inflammation, and further exposed to cannabinoid receptor agonists. In order to evaluate nerve density, tracheal segments were also examined by immunohistochemistry after in vitro treatments. The CB1 receptor agonists ACEA and ACPA inhibited the constant train EFS-induced contractions in both fresh and NGF-exposed tracheas, an effect that could be blocked by the CB1 receptor antagonist AM251. Culturing the tissues with NGF up-regulated the frequency-dependent EFS-contractions in isolated tracheas. This up-regulation could be inhibited by concomitant treatment with ACEA or ACPA. The treatment with NGF and/or ACEA did not affect the potency or the maximum response to carbachol. In histological sections, it was recognized that the enhanced effect induced by NGF was associated with an increase in nerve density, which, similarly, could be prevented by ACEA treatment. This study shows that stimulation of cannabinoid CB1 receptors modifies the increase of neuronal activity and density in NGF-induced airway inflammation and directly inhibits cholinergic contractions in the airways by a presynaptic mechanism. These findings indicate a protective role of CB1 receptors in airway inflammation.

  18. Lack of CB1 receptors increases noradrenaline release in vas deferens without affecting atrial noradrenaline release or cortical acetylcholine release

    OpenAIRE

    Schlicker, Eberhard; Redmer, Agnes; Werner, André; Kathmann, Markus

    2003-01-01

    We studied whether cannabinoid CB1 receptor gene disruption (to yield CB1−/− mice) affects the electrically evoked tritium overflow from vas deferens and atrial pieces preincubated with [3H]-noradrenaline (NA) (‘noradrenaline release') and from cerebral cortex slices preincubated with [3H]-choline (‘acetylcholine release').NA release was higher by 37% in vas deferens from CB1−/− mice than in vas deferens from CB1+/+ mice. The cannabinoid receptor agonist WIN 55,212-2 inhibited, and the CB1 re...

  19. Paranoid schizophrenia is characterized by increased CB1 receptor binding in the dorsolateral prefrontal cortex.

    Science.gov (United States)

    Dalton, Victoria S; Long, Leonora E; Weickert, Cyndi Shannon; Zavitsanou, Katerina

    2011-07-01

    A number of studies suggest a dysregulation of the endogenous cannabinoid system in schizophrenia (SCZ). In the present study, we examined cannabinoid CB(1) receptor (CB(1)R) binding and mRNA expression in the dorsolateral prefrontal cortex (DLPFC) (Brodmann's area 46) of SCZ patients and controls, post-mortem. Receptor density was investigated using autoradiography with the CB(1)R ligand [(3)H] CP 55,940 and CB(1)R mRNA expression was measured using quantitative RT-PCR in a cohort of 16 patients with paranoid SCZ, 21 patients with non-paranoid SCZ and 37 controls matched for age, post-mortem interval and pH. All cases were obtained from the University of Sydney Tissue Resource Centre. Results were analyzed using one-way analysis of variance (ANOVA) and post hoc Bonferroni tests and with analysis of covariance (ANCOVA) to control for demographic factors that would potentially influence CB(1)R expression. There was a main effect of diagnosis on [(3)H] CP 55,940 binding quantified across all layers of the DLPFC (F(2,71) = 3.740, p = 0.029). Post hoc tests indicated that this main effect was due to patients with paranoid SCZ having 22% higher levels of CB(1)R binding compared with the control group. When ANCOVA was employed, this effect was strengthened (F(2,67) = 6.048, p = 0.004) with paranoid SCZ patients differing significantly from the control (p = 0.004) and from the non-paranoid group (p = 0.016). In contrast, no significant differences were observed in mRNA expression between the different disease subtypes and the control group. Our findings confirm the existence of a CB(1)R dysregulation in SCZ and underline the need for further investigation of the role of this receptor particularly in those diagnosed with paranoid SCZ.

  20. Modeling of ligand binding to G protein coupled receptors: cannabinoid CB1, CB2 and adrenergic β 2 AR.

    Science.gov (United States)

    Latek, Dorota; Kolinski, Michal; Ghoshdastider, Umesh; Debinski, Aleksander; Bombolewski, Rafal; Plazinska, Anita; Jozwiak, Krzysztof; Filipek, Slawomir

    2011-09-01

    Cannabinoid and adrenergic receptors belong to the class A (similar to rhodopsin) G protein coupled receptors. Docking of agonists and antagonists to CB(1) and CB(2) cannabinoid receptors revealed the importance of a centrally located rotamer toggle switch and its possible participation in the mechanism of agonist/antagonist recognition. The switch is composed of two residues, F3.36 and W6.48, located on opposite transmembrane helices TM3 and TM6 in the central part of the membranous domain of cannabinoid receptors. The CB(1) and CB(2) receptor models were constructed based on the adenosine A(2A) receptor template. The two best scored conformations of each receptor were used for the docking procedure. In all poses (ligand-receptor conformations) characterized by the lowest ligand-receptor intermolecular energy and free energy of binding the ligand type matched the state of the rotamer toggle switch: antagonists maintained an inactive state of the switch, whereas agonists changed it. In case of agonists of β(2)AR, the (R,R) and (S,S) stereoisomers of fenoterol, the molecular dynamics simulations provided evidence of different binding modes while preserving the same average position of ligands in the binding site. The (S,S) isomer was much more labile in the binding site and only one stable hydrogen bond was created. Such dynamical binding modes may also be valid for ligands of cannabinoid receptors because of the hydrophobic nature of their ligand-receptor interactions. However, only very long molecular dynamics simulations could verify the validity of such binding modes and how they affect the process of activation.

  1. Suppression of outward K⁺ currents by WIN55212-2 in rat retinal ganglion cells is independent of CB1/CB2 receptors.

    Science.gov (United States)

    Zhang, C-Q; Wu, H-J; Wang, S-Y; Yin, S; Lu, X-J; Miao, Y; Wang, X-H; Yang, X-L; Wang, Z

    2013-12-03

    Cannabinoid CB1 receptor (CB1R) signaling system is extensively distributed in the vertebrate retina. Activation of CB1Rs regulates a variety of functions of retinal neurons through modulating different ion channels. In the present work we studied effects of this receptor signaling on K(+) channels in retinal ganglion cells by patch-clamp techniques. The CB1R agonist WIN55212-2 (WIN) suppressed outward K(+) currents in acutely isolated rat retinal ganglion cells in a dose-dependent manner, with an IC50 of 4.7 μM. We further showed that WIN mainly suppressed the tetraethylammonium (TEA)-sensitive K(+) current component. While CB1Rs were expressed in rat retinal ganglion cells, the WIN effect on K(+) currents was not blocked by either AM251/SR141716, specific CB1R antagonists, or AM630, a selective CB2R antagonist. Consistently, cAMP-protein kinase A (PKA) and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathways were unlikely involved in the WIN-induced suppression of the K(+) currents because both PKA inhibitors H-89/Rp-cAMP and MAPK/ERK1/2 inhibitor U0126 failed to block the WIN effects. WIN-induced suppression of the K(+) currents was not observed when WIN was intracellularly applied. Furthermore, an endogenous ligand of the cannabinoid receptor anandamide, the specific CB1R agonist ACEA and the selective CB2R agonist CB65 also suppressed the K(+) currents, and the effects were not blocked by AM251/SR141716 or AM630 respectively. All these results suggest that the WIN-induced suppression of the outward K(+) currents in rat retinal ganglion cells, thereby regulating the cell excitability, were not through CB1R/CB2R signaling pathways.

  2. Differential effects of CB1 receptor agonism in behavioural tests of unconditioned and conditioned fear in adult male rats.

    Science.gov (United States)

    Simone, Jonathan J; Green, Matthew R; Hodges, Travis E; McCormick, Cheryl M

    2015-02-15

    We investigated the effects of the highly selective CB1 receptor agonist ACEA and the CB1 receptor antagonist/inverse agonist AM251 on two behavioural tests of unconditioned fear, the elevated plus maze (EPM) and open field test (OFT), as well as on the recall and extinction of a conditioned auditory fear. Both ACEA and AM251 increased anxiety-like behaviour in the EPM and OFT. There was no effect of either drug on recall of the conditioned fear, and ACEA enhanced and AM251 impaired fear extinction. Further, though both the low (0.1 mg/kg) and high (0.5 mg/kg) dose of ACEA facilitated fear extinction, the low dose attenuated, and the high dose potentiated, fear induced corticosterone release suggesting independent effects of the drug on fear and stress responses. Although the extent to which cannabinoids are anxiogenic or anxiolytic has been proposed to be dose-dependent, these results indicate that the same dose has differential effects across tasks, likely based in differences in sensitivities of CB1 receptors to the agonist in the neural regions subserving unconditioned and conditioned fear.

  3. Profiling two indole-2-carboxamides for allosteric modulation of the CB1 receptor.

    Science.gov (United States)

    Ahn, Kwang H; Mahmoud, Mariam M; Samala, Sushma; Lu, Dai; Kendall, Debra A

    2013-03-01

    Allosteric modulation of G-protein coupled receptors (GPCRs) represents a novel approach for fine-tuning GPCR functions. The cannabinoid CB1 receptor, a GPCR associated with the CNS, has been implicated in the treatment of drug addiction, pain, and appetite disorders. We report here the synthesis and pharmacological characterization of two indole-2-carboxamides:5-chloro-3-ethyl-1-methyl-N-(4-(piperidin-1-yl)phenethyl)-1H-indole-2-carboxamide (ICAM-a) and 5-chloro-3-pentyl-N-(4-(piperidin-1-yl)phenethyl)-1H-indole-2-carboxamide (ICAM-b). Although both ICAM-a and ICAM-b enhanced CP55, 940 binding, ICAM-b exhibited the strongest positive cooperativity thus far demonstrated for enhancing agonist binding to the CB1 receptor. Although it displayed negative modulatory effects on G-protein coupling to CB1, ICAM-b induced β-arrestin-mediated downstream activation of extracellular signal-regulated kinase (ERK) signaling. These results indicate that this compound represents a novel class of CB1 ligands that produce biased signaling via CB1.

  4. Preferential epithelial expression of type-1 cannabinoid receptor (CB1R) in the developing canine embryo

    OpenAIRE

    2015-01-01

    The use of cannabinoid receptor agonists is gaining a strong interest both in human and veterinary medicine. The potential use of cannabimimetic compounds in companion animals was reviewed in 2007 for their role in tissue inflammation and pain. A better knowledge of type-1 cannabinoid receptor (CB1R) expression on the target population may help in risk management in order to prevent unwanted side effects. We used 30-days old canine embryos to describe the distribution of CB1R by means of immu...

  5. Characterization of a novel, brain-penetrating CB1 receptor inverse agonist: metabolic profile in diet-induced obese models and aspects of central activity.

    Science.gov (United States)

    Jacobson, Laura H; Commerford, S Renee; Gerber, Sarah P; Chen, Yu Alice; Dardik, Beatriz; Chaperon, Frederique; Schwartzkopf, Chad; Nguyen-Tran, Van; Hollenbeck, Thomas; McNamara, Peter; He, Xiaohui; Liu, Hong; Seidel, H Martin; Jaton, Anne-Liese; Gromada, Jesper; Teixeira, Sandra

    2011-12-01

    Pharmacologic antagonism of cannabinoid 1 receptors (CB1 receptors) in the central nervous system (CNS) suppresses food intake, promotes weight loss, and improves the metabolic profile. Since the CB1 receptor is expressed both in the CNS and in peripheral tissues, therapeutic value may be gained with CB1 receptor inverse agonists acting on receptors in both domains. The present report examines the metabolic and CNS actions of a novel CB1 receptor inverse agonist, compound 64, a 1,5,6-trisubstituted pyrazolopyrimidinone. Compound 64 showed similar or superior binding affinity, in vitro potency, and pharmacokinetic profile compared to rimonabant. Both compounds improved the metabolic profile in diet-induced obese (DIO) rats and obese cynomolgus monkeys. Weight loss tended to be greater in compound 64-treated DIO rats compared to pair-fed counterparts, suggesting that compound 64 may have metabolic effects beyond those elicited by weight loss alone. In the CNS, reversal of agonist-induced hypothermia and hypolocomotion indicated that compound 64 possessed an antagonist activity in vivo. Dosed alone, compound 64 suppressed extinction of conditioned freezing (10 mg/kg) and rapid eye movement (REM) sleep (30 mg/kg), consistent with previous reports for rimonabant, although for REM sleep, compound 64 was greater than threefold less potent than for metabolic effects. Together, these data suggested that (1) impairment of extinction learning and REM sleep suppression are classic, centrally mediated responses to CB1 receptor inverse agonists, and (2) some separation may be achievable between central and peripheral effects with brain-penetrating CB1 receptor inverse agonists while maintaining metabolic efficacy. Furthermore, chronic treatment with compound 64 contributes to evidence that peripheral CB1 receptor blockade may yield beneficial outcomes that exceed those elicited by weight loss alone.

  6. Adolescent chronic mild stress alters hippocampal CB1 receptor-mediated excitatory neurotransmission and plasticity.

    Science.gov (United States)

    Reich, C G; Mihalik, G R; Iskander, A N; Seckler, J C; Weiss, M S

    2013-12-03

    Endocannabinoids (eCBs) are involved in the stress response and alterations in eCB signaling may contribute to the etiology of mood disorders. Exposure to chronic mild stress (CMS), a model of depression, produces downregulation of the cannabinoid 1 (CB1) receptor in the hippocampus of male rats. However, it is unknown how this stress-induced change in CB1 levels affects eCB-mediated neurotransmission. In vitro, field potential recordings from CMS-exposed (21-days) rats were performed to assess the effects of stress on eCB-regulated glutamatergic neurotransmission in/on hippocampal area CA1. We observed that application of the CB1 agonist, WIN 55,212-5 (1 μM), in stress animals resulted in a ∼135% increase in excitatory neurotransmission, whereas CB1 activation in non-stress animals leads to a ∼30% decrease. However, during blockade of GABA(A) neurotransmission with picrotoxin, CB1 activation yielded a ∼35% decrease in stress animals. These findings indicate that CMS does not directly affect glutamatergic neurotransmission. Rather, CMS sensitizes CB1 function on GABAergic terminals, leading to less inhibition and an increase in excitatory neurotransmission. This finding is reinforced in that induction of weak long-term-potentiation (LTP) is enhanced in CMS-exposed animals compared to controls and this enhancement is CB1-dependent. Lastly, we observed that the LTP-blocking property of WIN 55,212-5 shifts from being glutamate-dependent in non-stress animals to being GABA-dependent in stress animals. These results effectively demonstrate that CMS significantly alters hippocampal eCB-mediated neurotransmission and synaptic plasticity.

  7. Neural endocannabinoid CB1 receptor expression, social status, and behavior in male European starlings.

    Science.gov (United States)

    DeVries, M Susan; Cordes, Melissa A; Rodriguez, Jonathan D; Stevenson, Sharon A; Riters, Lauren V

    2016-08-01

    Many species modify behavior in response to changes in resource availability or social status; however, the neural mechanisms underlying these modifications are not well understood. Prior work in male starlings demonstrates that status-appropriate changes in behavior involve brain regions that regulate social behavior and vocal production. Endocannabinoids are ubiquitously distributed neuromodulators that are proposed to play a role in adjusting behavior to match social status. As an initial step to provide insight into this hypothesis we observed flocks of male starlings in outdoor aviaries during the breeding season. We used quantitative real-time PCR to measure expression of endocannabinoid CB1 receptors in brain regions involved in social behavior and motivation (lateral septum [LS], ventral tegmental area [VTA], medial preoptic nucleus [POM]) and vocal behavior (Area X and robust nucleus of the arcopallium; RA). Males with nesting sites sang to females and displaced other males more than males without nesting sites. They also had higher levels of CB1 receptor expression in LS and RA. CB1 expression in LS correlated positively with agonistic behaviors. CB1 expression in RA correlated positively with singing behavior. CB1 in VTA also correlated positively with singing when only singing birds were considered. These correlations nicely map onto the well-established role of LS in agonistic behavior and the known role of RA in song production and VTA in motivation and song production. Studies are now needed to precisely characterize the role of CB1 receptors in these regions in the production of status-appropriate social behaviors.

  8. CB1 cannabinoid receptor-mediated anandamide signalling reduces the defensive behaviour evoked through GABAA receptor blockade in the dorsomedial division of the ventromedial hypothalamus.

    Science.gov (United States)

    Dos Anjos-Garcia, Tayllon; Ullah, Farhad; Falconi-Sobrinho, Luiz Luciano; Coimbra, Norberto Cysne

    2017-02-01

    The effects of cannabinoids in brain areas expressing cannabinoid receptors, such as hypothalamic nuclei, are not yet well known. Several studies have demonstrated the role of hypothalamic nuclei in the organisation of behavioural responses induced through innate fear and panic attacks. Panic-prone states are experimentally induced in laboratory animals through a reduction in the GABAergic activity. The aim of the present study was to examine panic-like elaborated defensive behaviour evoked by GABAA receptor blockade with bicuculline (BIC) in the dorsomedial division of the ventromedial hypothalamus (VMHdm). We also aimed to characterise the involvement of endocannabinoids and the CB1 cannabinoid receptor in the modulation of elaborated defence behavioural responses organised with the VMHdm. The guide-cannula was stereotaxicaly implanted in VMHdm and the animals were treated with anandamide (AEA) at different doses, and the effective dose was used after the pre-treatment with the CB1 receptor antagonist AM251, followed by GABAA receptor blockade in VMHdm. The results showed that the intra-hypothalamic administration of AEA at an intermediate dose (5 pmol) attenuated defence responses induced through the intra-VMHdm microinjection of bicuculline (40 ng). This effect, however, was inhibited when applied central microinjection of the CB1 receptor antagonist AM251 in the VMHdm. Moreover, AM251 potentiates de non-oriented escape induced by bicuculline, effect blocked by pre-treatment with the TRPV1 channel antagonist 6-I-CPS. These results indicate that AEA modulates the pro-aversive effects of intra-VMHdm-bicuculline treatment, recruiting CB1 cannabinoid receptors and the TRPV1 channel is involved in the AM251-related potentiation of bicuculline effects on non-oriented escape behaviour.

  9. CB1 receptors in the formation of the different phases of memory-related processes in the inhibitory avoidance test in mice.

    Science.gov (United States)

    Kruk-Slomka, Marta; Biala, Grażyna

    2016-03-15

    The endocannabinoid system, through the cannabinoid type 1 (CB1) and 2 (CB2) receptors modulates many physiological functions, including different aspects of memory-related processes. The aim of the present experiments was to explore the role of the endocannabinoid system, through CB1 receptors in the different stages of short-term (acquisition, retention and retrieval) and long-term (acquisition, consolidation and retrieval) memory-related responses, using the inhibitory avoidance (IA) test in mice. Our results revealed that an acute injection of oleamide (10 and 20mg/kg), a CB1 receptor agonist, impairs the short-term or/and long-term acquisition, retention/consolidation, retrieval memory and learning processes in the IA test in mice. In turn, in this test an acute injection of AM 251 (1 and 3mg/kg), a CB1 receptor antagonist, improves the short-term or/and long-term memory stages, described above. Moreover, this memory impairment induced by effective dose of oleamide (20mg/kg) is reversed by non-effective dose of AM 251 (0.25mg/kg) in the IA task, which proves the selectivity of oleamide to CB1 receptors and confirms that the CB1 receptor-related mechanism is one of the possible mechanisms, responsible for memory and learning responses. Obtained results provide clear evidence that the endocannabinoid system, through CB1 receptors, participates in the different stages of short- and long-term memory-related behavior. This knowledge may open in the future new possibilities for the development of CB-based therapies, especially for memory impairment human disorders.

  10. Biphasic Effects of Cannabinoids in Anxiety Responses: CB1 and GABAB Receptors in the Balance of GABAergic and Glutamatergic Neurotransmission

    Science.gov (United States)

    Rey, Alejandro Aparisi; Purrio, Martin; Viveros, Maria-Paz; Lutz, Beat

    2012-01-01

    Biphasic effects of cannabinoids have been shown in processes such as feeding behavior, motor activity, motivational processes and anxiety responses. Using two different tests for the characterization of anxiety-related behavior (elevated plus-maze and holeboard), we first identified in wild-type C57BL/6N mice, two doses of the synthetic CB1 cannabinoid receptor agonist CP-55,940 with anxiolytic (1 μg/kg) and anxiogenic properties (50 μg/kg), respectively. To clarify the role of CB1 receptors in this biphasic effect, both doses were applied to two different conditional CB1 receptor knockout (KO) mouse lines, GABA-CB1-KO (CB1 receptor inactivation in forebrain GABAergic neurons) and Glu-CB1-KO (CB1 receptor inactivation in cortical glutamatergic neurons). We found that the anxiolytic-like effects of the low dose of cannabinoids are mediated via the CB1 receptor on cortical glutamatergic terminals, because this anxiolytic-like response was abrogated only in Glu-CB1-KO mice. On the contrary, the CB1 receptor on the GABAergic terminals is required to induce an anxiogenic-like effect under a high-dose treatment because of the fact that this effect was abolished specifically in GABA-CB1-KO mice. These experiments were carried out in both sexes, and no differences occurred with the doses tested in the mutant mice. Interestingly, the positive allosteric modulation of GABAB receptor with GS-39783 was found to largely abrogate the anxiogenic-like effect of the high dose of CP-55,940. Our results shed new light in further understanding the biphasic effects of cannabinoids at the molecular level and, importantly, pave the way for the development of novel anxiolytic cannabinoid drugs, which may have favorable effect profiles targeting the CB1 receptor on glutamatergic terminals. PMID:22850737

  11. CB1 Cannabinoid Receptors Modulate Kinase and Phosphatase Activity during Extinction of Conditioned Fear in Mice

    Science.gov (United States)

    Kamprath, Kornelia; Hermann, Heike; Lutz, Beat; Marsicano, Giovanni; Cannich, Astrid; Wotjak, Carsten T.

    2004-01-01

    Cannabinoid receptors type 1 (CB1) play a central role in both short-term and long-term extinction of auditory-cued fear memory. The molecular mechanisms underlying this function remain to be clarified. Several studies indicated extracellular signal-regulated kinases (ERKs), the phosphatidylinositol 3-kinase with its downstream effector AKT, and…

  12. Modulation of The Balance Between Cannabinoid CB1 and CB2 Receptor Activation During Cerebral Ischemic/Reperfusion Injury

    OpenAIRE

    ZHANG, Ming; Martin, Billy R.; Adler, Martin W.; Razdan, Raj K.; Ganea, Doina; Tuma, Ronald F.

    2008-01-01

    Cannabinoid receptor activation has been shown to modulate both neurotransmission (CB1) and neuroinflammatory (CB2) responses. There are conflicting reports in the literature describing the influence of cannabinoid receptor activation on ischemic/reperfusion injury. The goal of this study was to evaluate how changing the balance between CB1 and CB2 activation following cerebral ischemia influences outcome. CB1 and CB2 expression were tested at different times after transient middle cerebral a...

  13. Photoperiodic changes in endocannabinoid levels and energetic responses to altered signalling at CB1 receptors in Siberian hamsters.

    Science.gov (United States)

    Ho, J M; Smith, N S; Adams, S A; Bradshaw, H B; Demas, G E

    2012-07-01

    Siberian hamsters (Phodopus sungorus) adapt to seasonal environmental conditions with marked changes in body mass, primarily in the form of adiposity. Winter-like conditions (e.g. short days) are sufficient to decrease body mass by approximately 30% in part via reductions in food intake. The neuroendocrine mechanisms responsible for these changes are not well understood, and homeostatic orexigenic/anorexigenic systems of the hypothalamus provide little explanation. We investigated the potential role of endocannabinoids, which are known modulators of appetite and metabolism, in mediating seasonal changes in energy balance. Specifically, we housed hamsters in long or short days for 0, 3, or 9 weeks and measured endocannabinoid levels in the hypothalamus, brainstem, liver and retroperitoneal white adipose tissue (RWAT). An additional group of males housed in short days for 25 weeks were also compared with long-day controls. Following 9 weeks in short days, levels of the endocannabinoid 2-arachidonoylglycerol (2-AG) were significantly elevated in RWAT and reduced in brainstem, although they returned to long-day levels by week 25 in short-day males that had cycled back to summer-like energy balance. Endocannabinoid levels in these tissues correlated significantly with adiposity and change in body mass. No photoperiodic changes were observed in the hypothalamus or liver; however, sex differences in 2-AG levels were found in the liver (males > females). We further tested the effects of CB(1) receptor signalling on ingestive behaviour. Five daily injections of CB(1) antagonist SR141716 significantly reduced food intake and body mass but not food hoarding. Although the CB(1) agonist arachidonyl-2-chloroethylamide did not appreciably affect either ingestive behaviour, body mass was significantly elevated following 2 days of injections. Taken altogether, these findings demonstrate that endocannabinoid levels vary with sex and photoperiod in a site-specific manner, and that

  14. Ghrelin-induced orexigenic effect in rats depends on the metabolic status and is counteracted by peripheral CB1 receptor antagonism.

    Directory of Open Access Journals (Sweden)

    Francisco Alen

    Full Text Available Ghrelin is an endogenous regulator of energy homeostasis synthesized by the stomach to stimulate appetite and positive energy balance. Similarly, the endocannabinoid system is part of our internal machinery controlling food intake and energy expenditure. Both peripheral and central mechanisms regulate CB1-mediated control of food intake and a functional relationship between hypothalamic ghrelin and cannabinoid CB1 receptor has been proposed. First of all, we investigated brain ghrelin actions on food intake in rats with different metabolic status (negative or equilibrate energy balance. Secondly, we tested a sub-anxiogenic ultra-low dose of the CB1 antagonist SR141716A (Rimonabant and the peripheral-acting CB1 antagonist LH-21 on ghrelin orexigenic actions. We found that: 1 central administration of ghrelin promotes food intake in free feeding animals but not in 24 h food-deprived or chronically food-restricted animals; 2 an ultra-low dose of SR141716A (a subthreshold dose 75 folds lower than the EC50 for induction of anxiety completely counteracts the orexigenic actions of central ghrelin in free feeding animals; 3 the peripheral-restricted CB1 antagonist LH-21 blocks ghrelin-induced hyperphagia in free feeding animals. Our study highlights the importance of the animaĺs metabolic status for the effectiveness of ghrelin in promoting feeding, and suggests that the peripheral endocannabinoid system may interact with ghrelińs signal in the control of food intake under equilibrate energy balance conditions.

  15. Ghrelin-Induced Orexigenic Effect in Rats Depends on the Metabolic Status and Is Counteracted by Peripheral CB1 Receptor Antagonism

    Science.gov (United States)

    Alen, Francisco; Crespo, Inmaculada; Ramírez-López, María Teresa; Jagerovic, Nadine; Goya, Pilar; de Fonseca, Fernando Rodríguez; de Heras, Raquel Gómez; Orio, Laura

    2013-01-01

    Ghrelin is an endogenous regulator of energy homeostasis synthesized by the stomach to stimulate appetite and positive energy balance. Similarly, the endocannabinoid system is part of our internal machinery controlling food intake and energy expenditure. Both peripheral and central mechanisms regulate CB1-mediated control of food intake and a functional relationship between hypothalamic ghrelin and cannabinoid CB1 receptor has been proposed. First of all, we investigated brain ghrelin actions on food intake in rats with different metabolic status (negative or equilibrate energy balance). Secondly, we tested a sub-anxiogenic ultra-low dose of the CB1 antagonist SR141716A (Rimonabant) and the peripheral-acting CB1 antagonist LH-21 on ghrelin orexigenic actions. We found that: 1) central administration of ghrelin promotes food intake in free feeding animals but not in 24 h food-deprived or chronically food-restricted animals; 2) an ultra-low dose of SR141716A (a subthreshold dose 75 folds lower than the EC50 for induction of anxiety) completely counteracts the orexigenic actions of central ghrelin in free feeding animals; 3) the peripheral-restricted CB1 antagonist LH-21 blocks ghrelin-induced hyperphagia in free feeding animals. Our study highlights the importance of the animaĺs metabolic status for the effectiveness of ghrelin in promoting feeding, and suggests that the peripheral endocannabinoid system may interact with ghrelińs signal in the control of food intake under equilibrate energy balance conditions. PMID:23565287

  16. Role of Endocannabinoid Activation of Peripheral CB1 Receptors in the Regulation of Autoimmune Disease

    Science.gov (United States)

    Sido, Jessica Margaret; Nagarkatti, Prakash S.; Nagarkatti, Mitzi

    2014-01-01

    The impact of the endogenous cannabinoids (AEA, 2-AG, PEA, and virodamine) on the immune cell expressed cannabinoid receptors (CB1, CB2, TRPV-1, and GPR55) and consequent regulation of immune function is an exciting area of research with potential implications in the prevention and treatment of inflammatory and autoimmune diseases. Despite significant advances in understanding the mechanisms through which cannabinoids regulate immune functions, not much is known about the role of endocannabinoids in the pathogenesis or prevention of autoimmune diseases. Inasmuch as CB2 expression on immune cells and its role has been widely reported, the importance of CB1 in immunological disorders has often been overlooked especially because it is not highly expressed on naive immune cells. Therefore, the current review aims at delineating the effect of endocannabinoids on CB1 receptors in T cell driven autoimmune diseases. This review will also highlight some autoimmune diseases in which there is evidence indicating a role for endocannabinoids in the regulation of autoimmune pathogenesis. Overall, based on the evidence presented using the endocannabinoids, specifically AEA, we propose that the peripheral CB1 receptor is involved in the regulation and amelioration of inflammation associated with autoimmune diseases. PMID:24911431

  17. Pre-synaptic adenosine A2A receptors control cannabinoid CB1 receptor-mediated inhibition of striatal glutamatergic neurotransmission.

    Science.gov (United States)

    Martire, Alberto; Tebano, Maria Teresa; Chiodi, Valentina; Ferreira, Samira G; Cunha, Rodrigo A; Köfalvi, Attila; Popoli, Patrizia

    2011-01-01

    An interaction between adenosine A(2A) receptors (A(2A) Rs) and cannabinoid CB(1) receptors (CB(1) Rs) has been consistently reported to occur in the striatum, although the precise mechanisms are not completely understood. As both receptors control striatal glutamatergic transmission, we now probed the putative interaction between pre-synaptic CB(1) R and A(2A) R in the striatum. In extracellular field potentials recordings in corticostriatal slices from Wistar rats, A(2A) R activation by CGS21680 inhibited CB(1) R-mediated effects (depression of synaptic response and increase in paired-pulse facilitation). Moreover, in superfused rat striatal nerve terminals, A(2A) R activation prevented, while A(2A) R inhibition facilitated, the CB(1) R-mediated inhibition of 4-aminopyridine-evoked glutamate release. In summary, the present study provides converging neurochemical and electrophysiological support for the occurrence of a tight control of CB(1) R function by A(2A) Rs in glutamatergic terminals of the striatum. In view of the key role of glutamate to trigger the recruitment of striatal circuits, this pre-synaptic interaction between CB(1) R and A(2A) R may be of relevance for the pathogenesis and the treatment of neuropsychiatric disorders affecting the basal ganglia.

  18. [18F]MK-9470 PET measurement of cannabinoid CB1 receptor availability in chronic cannabis users.

    Science.gov (United States)

    Ceccarini, Jenny; Kuepper, Rebecca; Kemels, Dieter; van Os, Jim; Henquet, Cécile; Van Laere, Koen

    2015-03-01

    Δ(9) -Tetrahydrocannabinol, the main psychoactive component of cannabis, exerts its central effects through activation of the cerebral type 1 cannabinoid (CB1 ) receptor. Pre-clinical studies have provided evidence that chronic cannabis exposure is linked to decreased CB1 receptor expression and this is thought to be a component underlying drug tolerance and dependence. In this study, we make first use of the selective high-affinity positron emission tomography (PET) ligand [(18) F]MK-9470 to obtain in vivo measurements of cerebral CB1 receptor availability in 10 chronic cannabis users (age = 26.0 ± 4.1 years). Each patient underwent [(18) F]MK-9470 PET within the first week following the last cannabis consumption. A population of 10 age-matched healthy subjects (age = 23.0 ± 2.9 years) was used as control group. Parametric modified standardized uptake value images, reflecting CB1 receptor availability, were calculated. Statistical parametric mapping and volume-of-interest (VOI) analyses of CB1 receptor availability were performed. Compared with controls, cannabis users showed a global decrease in CB1 receptor availability (-11.7 percent). VOI-based analysis demonstrated that the CB1 receptor decrease was significant in the temporal lobe (-12.7 percent), anterior (-12.6 percent) and posterior cingulate cortex (-13.5 percent) and nucleus accumbens (-11.2 percent). Voxel-based analysis confirmed this decrease and regional pattern in CB1 receptor availability in cannabis users. These findings revealed that chronic cannabis use may alter specific regional CB1 receptor expression through neuroadaptive changes in CB1 receptor availability, opening the way for the examination of specific CB1 -cannabis addiction interactions which may predict future cannabis-related treatment outcome.

  19. Brain regional differences in CB1 receptor adaptation and regulation of transcription.

    Science.gov (United States)

    Lazenka, M F; Selley, D E; Sim-Selley, L J

    2013-03-19

    Cannabinoid CB1 receptors (CB1Rs) are expressed throughout the brain and mediate the central effects of cannabinoids, including Δ(9)-tetrahydrocannabinol (THC), the main psychoactive constituent of marijuana. Repeated THC administration produces tolerance to cannabinoid-mediated effects, although the magnitude of tolerance varies by effect. Consistent with this observation, CB1R desensitization and downregulation, as well as induction of immediate early genes (IEGs), vary by brain region. Zif268 and c-Fos are induced in the forebrain after acute THC administration. Phosphorylation of the cAMP response-element binding protein (CREB) is increased in a region-specific manner after THC administration. Results differ between acute versus repeated THC injection, and suggest that tolerance to IEG activation might develop in some regions. Repeated THC treatment produces CB1R desensitization and downregulation in the brain, although less adaption occurs in the striatum as compared to regions such as the hippocampus. Repeated THC treatment also induces expression of ΔFosB, a very stable isoform of FosB, in the striatum. Transgenic expression of ∆FosB in the striatum enhances the rewarding effects of several drugs, but its role in THC-mediated effects is not known. The inverse regional relationship between CB1R desensitization and ∆FosB induction suggests that these adaptations might inhibit each other, although this possibility has not been investigated. The differential regional expression of individual IEGs by acute or repeated THC administration suggests that regulation of target genes and effects on CB1R signaling will contribute to the behavioral effects of THC.

  20. Elevation of endogenous anandamide impairs LTP, learning, and memory through CB1 receptor signaling in mice.

    Science.gov (United States)

    Basavarajappa, Balapal S; Nagre, Nagaraja N; Xie, Shan; Subbanna, Shivakumar

    2014-07-01

    In rodents, many exogenous and endogenous cannabinoids, such as anandamide (AEA) and 2-arachidonyl glycerol (2-AG), have been shown to play an important role in certain hippocampal memory processes. However, the mechanisms by which endogenous AEA regulate this processes are not well understood. Here the effects of AEA on long-term potentiation (LTP), hippocampal-dependent learning and memory tasks, pERK1/2, pCaMKIV, and pCREB signaling events in both cannabinoid receptor type 1 (CB1R) wild-type (WT) and knockout (KO) mice were assessed following administration of URB597, an inhibitor of the fatty acid amide hydrolase (FAAH). Acute administration of URB597 enhanced AEA levels without affecting the levels of 2-AG or CB1R in the hippocampus and neocortex as compared to vehicle. In hippocampal slices, URB597 impaired LTP in CB1R WT but not in KO littermates. URB597 impaired object recognition, spontaneous alternation and spatial memory in the Y-maze test in CB1R WT mice but not in KO mice. Furthermore, URB597 enhanced ERK phosphorylation in WT without affecting total ERK levels in WT or KO mice. URB597 impaired CaMKIV and CREB phosphorylation in WT but not in KO mice. CB1R KO mice have a lower pCaMKIV/CaMKIV ratio and higher pCREB/CREB ratio as compared to WT littermates. Our results indicate that pharmacologically elevated AEA impair LTP, learning and memory and inhibit CaMKIV and CREB phosphorylation, via the activation of CB1Rs. Collectively, these findings also suggest that pharmacological elevation of AEA beyond normal concentrations is also detrimental for the underlying physiological responses.

  1. Contribution of hypothermia and CB1 receptor activation to protective effects of TAK-937, a cannabinoid receptor agonist, in rat transient MCAO model.

    Directory of Open Access Journals (Sweden)

    Noriko Suzuki

    Full Text Available BACKGROUND: Cannabinoid (CB receptor agonists are expected to alleviate ischemic brain damage by modulating neurotransmission and neuroinflammatory responses via CB(1 and CB(2 receptors, respectively. In a previous study, TAK-937, a novel potent and selective CB(1 and CB(2 receptor agonist, was shown to exert significant cerebroprotective effects accompanied by hypothermia after transient middle cerebral artery occlusion (MCAO in rats. Sustained hypothermia itself induces significant neuroprotective effects. In the present studies, we examined the relative contribution of hypothermia and CB(1 receptor activation to the cerebroprotective effects of TAK-937. METHODOLOGY/PRINCIPAL FINDINGS: Using a multichannel brain temperature controlling system we developed, the brain temperature of freely moving rats was telemetrically monitored and maintained between 37 and 38°C during intravenous infusion of TAK-937 (100 µg/kg/h or vehicle for 24 h after 2 h MCAO. AM251, a selective CB(1 receptor antagonist, was administered intraperitoneally at 30 mg/kg 30 min before starting intravenous infusion of TAK-937 (100 µg/kg/h for 24 h. Rats were sacrificed and their brains were isolated 26 h after MCAO in both experiments. When the hypothermic effect of TAK-937 was completely reversed by a brain temperature controlling system, the infarct-reducing effect of TAK-937 was attenuated in part, but remained significant. On the other hand, concomitant AM251 treatment with TAK-937 completely abolished the hypothermic and infarct-reducing effects of TAK-937. CONCLUSIONS/SIGNIFICANCE: We conclude that the cerebroprotective effects of TAK-937 were at least in part mediated by induction of hypothermia, and mainly mediated by CB(1 receptor activation.

  2. Evidence against a critical role of CB1 receptors in adaptation of the hypothalamic-pituitary-adrenal axis and other consequences of daily repeated stress.

    Science.gov (United States)

    Rabasa, Cristina; Pastor-Ciurana, Jordi; Delgado-Morales, Raúl; Gómez-Román, Almudena; Carrasco, Javier; Gagliano, Humberto; García-Gutiérrez, María S; Manzanares, Jorge; Armario, Antonio

    2015-08-01

    There is evidence that endogenous cannabinoids (eCBs) play a role in the control of the hypothalamic-pituitary-adrenal (HPA) axis, although they appear to have dual, stimulatory and inhibitory, effects. Recent data in rats suggest that eCBs, acting through CB1 receptors (CB1R), may be involved in adaptation of the HPA axis to daily repeated stress. In the present study we analyze this issue in male mice and rats. Using a knock-out mice for the CB1 receptor (CB1-/-) we showed that mutant mice presented similar adrenocorticotropic hormone (ACTH) response to the first IMO as wild-type mice. Daily repeated exposure to 1h of immobilization reduced the ACTH response to the stressor, regardless of the genotype, demonstrating that adaptation occurred to the same extent in absence of CB1R. Prototypical changes observed after repeated stress such as enhanced corticotropin releasing factor (CRH) gene expression in the paraventricular nucleus of the hypothalamus, impaired body weight gain and reduced thymus weight were similarly observed in both genotypes. The lack of effect of CB1R in the expression of HPA adaptation to another similar stressor (restraint) was confirmed in wild-type CD1 mice by the lack of effect of the CB1R antagonist AM251 just before the last exposure to stress. Finally, the latter drug did not blunt the HPA, glucose and behavioral adaptation to daily repeated forced swim in rats. Thus, the present results indicate that CB1R is not critical for overall effects of daily repeated stress or proper adaptation of the HPA axis in mice and rats.

  3. Development and Characterization of Immobilized Cannabinoid Receptor (CB1/CB2) Open Tubular Column for On-line Screening

    OpenAIRE

    Moaddel, R.; Rosenberg, A.; Spelman, K.; Frazier, J; Frazier, C.; Nocerino, S.; Brizzi, A; Mugnaini, C.; Wainer, I. W.

    2011-01-01

    Cannabinoid Receptors, CB1 and CB2, are therapeutic targets in the treatment of anxiety, obesity, movement disorders, glaucoma and pain. We have developed an on-line screening method for CB1 and CB2 ligands, where cellular membrane fragments of a chronic myelogenous leukemia cell line, (KU-812), were immobilized onto the surface of an open tubular capillary to create a CB1/CB2-OT column. The binding activities of the immobilized CB1/CB2 receptors were established using frontal affinity chroma...

  4. Differential β-arrestin2 requirements for constitutive and agonist-induced internalization of the CB1 cannabinoid receptor.

    Science.gov (United States)

    Gyombolai, Pál; Boros, Eszter; Hunyady, László; Turu, Gábor

    2013-06-15

    CB1 cannabinoid receptor (CB1R) undergoes both constitutive and agonist-induced internalization, but the underlying mechanisms of these processes and the role of β-arrestins in the regulation of CB1R function are not completely understood. In this study, we followed CB1R internalization using confocal microscopy and bioluminescence resonance energy transfer measurements in HeLa and Neuro-2a cells. We found that upon activation CB1R binds β-arrestin2 (β-arr2), but not β-arrestin1. Furthermore, both the expression of dominant-negative β-arr2 (β-arr2-V54D) and siRNA-mediated knock-down of β-arr2 impaired the agonist-induced internalization of CB1R. In contrast, neither β-arr2-V54D nor β-arr2-specific siRNA had a significant effect on the constitutive internalization of CB1R. However, both constitutive and agonist-induced internalization of CB1R were impaired by siRNA-mediated depletion of clathrin heavy chain. We conclude that although clathrin is required for both constitutive and agonist-stimulated internalization of CB1R, β-arr2 binding is only required for agonist-induced internalization of the receptor suggesting that the molecular mechanisms underlying constitutive and agonist-induced internalization of CB1R are different.

  5. Cannabinoid type 1 (CB1) receptors on Sim1-expressing neurons regulate energy expenditure in male mice.

    Science.gov (United States)

    Cardinal, Pierre; Bellocchio, Luigi; Guzmán-Quevedo, Omar; André, Caroline; Clark, Samantha; Elie, Melissa; Leste-Lasserre, Thierry; Gonzales, Delphine; Cannich, Astrid; Marsicano, Giovanni; Cota, Daniela

    2015-02-01

    The paraventricular nucleus of the hypothalamus (PVN) regulates energy balance by modulating not only food intake, but also energy expenditure (EE) and brown adipose tissue thermogenesis. To test the hypothesis that cannabinoid type 1 (CB1) receptor in PVN neurons might control these processes, we used the Cre/loxP system to delete CB1 from single-minded 1 (Sim1) neurons, which account for the majority of PVN neurons. On standard chow, mice lacking CB1 receptor in Sim1 neurons (Sim1-CB1-knockout [KO]) had food intake, body weight, adiposity, glucose metabolism, and EE comparable with wild-type (WT) (Sim1-CB1-WT) littermates. However, maintenance on a high-fat diet revealed a gene-by-diet interaction whereby Sim1-CB1-KO mice had decreased adiposity, improved insulin sensitivity, and increased EE, whereas feeding behavior was similar to Sim1-CB1-WT mice. Additionally, high-fat diet-fed Sim1-CB1-KO mice had increased mRNA expression of the β3-adrenergic receptor, as well as of uncoupling protein-1, cytochrome-c oxidase subunit IV and mitochondrial transcription factor A in the brown adipose tissue, all molecular changes suggestive of increased thermogenesis. Pharmacological studies using β-blockers suggested that modulation of β-adrenergic transmission play an important role in determining EE changes observed in Sim1-CB1-KO. Finally, chemical sympathectomy abolished the obesity-resistant phenotype of Sim1-CB1-KO mice. Altogether, these findings reveal a diet-dependent dissociation in the CB1 receptor control of food intake and EE, likely mediated by the PVN, where CB1 receptors on Sim1-positive neurons do not impact food intake but hinder EE during dietary environmental challenges that promote body weight gain.

  6. Effects of cannabinoid CB(1) receptor agonism and antagonism on SKF81297-induced dyskinesia and haloperidol-induced dystonia in Cebus apella monkeys

    DEFF Research Database (Denmark)

    Madsen, Morten V; Peacock, Linda P; Werge, Thomas

    2011-01-01

    81297 (SKF) and acute dystonia induced by the dopamine D(2) receptor antagonist haloperidol in Cebus apella monkeys. The monkeys were sensitised to EPS by prior exposure to D(2) receptor antagonists. SKF (0.3 mg/kg) was administered alone and in combination with the CB(1) agonist CP55,940 (0.......0025-0.01 mg/kg) or the CB(1) antagonist SR141716A (0.25-0.75 mg/kg). Haloperidol (individual doses at 0.01-0.02 mg/kg) was administered alone and in combination with CP55,940 (0.005 or 0.01 mg/kg) or SR141716A (0.5 or 0.75 mg/kg). Subsequently, the monkeys were videotaped, and the recordings were rated...

  7. Cannabinoid CB1 receptor recognition of endocannabinoids via the lipid bilayer: molecular dynamics simulations of CB1 transmembrane helix 6 and anandamide in a phospholipid bilayer

    Science.gov (United States)

    Lynch, Diane L.; Reggio, Patricia H.

    2006-08-01

    The phospholipid bilayer plays a central role in the lifecycle of the endogenous cannabinoid, N-arachidonoylethanolamine (anandamide, AEA). Therefore, the orientation and location of AEA in the phospholipid bilayer with respect to key membrane associated proteins, is a central issue in understanding the mechanism of endocannabinoid signaling. In this paper, we report a test of the hypothesis that a βXX β motif (formed by beta branching amino acids, V6.43 and I6.46) on the lipid face of the cannabinoid CB1 receptor in its inactive state may serve as an initial CB1 interaction site for AEA. Eight 6 ns NAMD2 molecular dynamics simulations of AEA were conducted in a model system composed of CB1 transmembrane helix 6 (TMH6) in a 1,2-dioleoyl- sn-glycero-3-phosphocholine (DOPC) bilayer. In addition, eight 6 ns NAMD2 molecular dynamics simulations of a low CB1 affinity (20:2, n-6) analog of AEA were conducted in the same model system. AEA was found to exhibit a higher incidence of V6.43/I6.46 groove insertion than did the (20:2, n-6) analog. In certain cases, AEA established a high energy of interaction with TMH6 by first associating with the V6.43/I6.46 groove and then molding itself to the lipid face of TMH6 to establish a hydrogen bonding interaction with the exposed backbone carbonyl of P6.50. Based upon these results, we propose that the formation of this hydrogen bonded AEA/TMH6 complex may be the initial step in CB1 recognition of AEA in the lipid bilayer.

  8. High tumour cannabinoid CB1 receptor immunoreactivity negatively impacts disease-specific survival in stage II microsatellite stable colorectal cancer.

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    Sofia B Gustafsson

    Full Text Available BACKGROUND: There is good evidence in the literature that the cannabinoid system is disturbed in colorectal cancer. In the present study, we have investigated whether CB(1 receptor immunoreactive intensity (CB(1IR intensity is associated with disease severity and outcome. METHODOLOGY/PRINCIPAL FINDINGS: CB(1IR was assessed in formalin-fixed, paraffin-embedded specimens collected with a consecutive intent during primary tumour surgical resection from a series of cases diagnosed with colorectal cancer. Tumour centre (n = 483 and invasive front (n = 486 CB(1IR was scored from 0 (absent to 3 (intense staining and the data was analysed as a median split i.e. CB(1IR <2 and ≥2. In microsatellite stable, but not microsatellite instable tumours (as adjudged on the basis of immunohistochemical determination of four mismatch repair proteins, there was a significant positive association of the tumour grade with the CB(1IR intensity. The difference between the microsatellite stable and instable tumours for this association of CB(1IR was related to the CpG island methylation status of the cases. Cox proportional hazards regression analyses indicated a significant contribution of CB(1IR to disease-specific survival in the microsatellite stable tumours when adjusting for tumour stage. For the cases with stage II microsatellite stable tumours, there was a significant effect of both tumour centre and front CB(1IR upon disease specific survival. The 5 year probabilities of event-free survival were: 85±5 and 66±8%; tumour interior, 86±4% and 63±8% for the CB(1IR<2 and CB(1IR≥2 groups, respectively. CONCLUSIONS/SIGNIFICANCE: The level of CB(1 receptor expression in colorectal cancer is associated with the tumour grade in a manner dependent upon the degree of CpG hypermethylation. A high CB(1IR is indicative of a poorer prognosis in stage II microsatellite stable tumour patients.

  9. GABAergic and Cortical and Subcortical Glutamatergic Axon Terminals Contain CB1 Cannabinoid Receptors in the Ventromedial Nucleus of the Hypothalamus

    OpenAIRE

    Leire Reguero; Nagore Puente; Izaskun Elezgarai; Juan Mendizabal-Zubiaga; Miren Josune Canduela; Ianire Buceta; Almudena Ramos; Juan Suárez; Fernando Rodríguez de Fonseca; Giovanni Marsicano; Pedro Grandes

    2011-01-01

    BACKGROUND: Type-1 cannabinoid receptors (CB(1)R) are enriched in the hypothalamus, particularly in the ventromedial hypothalamic nucleus (VMH) that participates in homeostatic and behavioral functions including food intake. Although CB(1)R activation modulates excitatory and inhibitory synaptic transmission in the brain, CB(1)R contribution to the molecular architecture of the excitatory and inhibitory synaptic terminals in the VMH is not known. Therefore, the aim of this study was to invest...

  10. Blockade of Cannabinoid CB1 receptor attenuates the acquisition of morphine-induced conditioned place preference along with a downregulation of ERK, CREB phosphorylation, and BDNF expression in the nucleus accumbens and hippocampus.

    Science.gov (United States)

    Zhang, Jianbo; Wang, Na; Chen, Bo; Wang, Yi'nan; He, Jing; Cai, Xintong; Zhang, Hongbo; Wei, Shuguang; Li, Shengbin

    2016-09-06

    Cannabinoid CB1 receptor (CB1R) is highly expressed in the mesocorticolimbic system and associated with drug craving and relapse. Clinical trials suggest that CB1R antagonists may represent new therapies for drug addiction. However, the downstream signaling of CB1R is not fully elucidated. In the present study, we investigated the relationship between CB1R and the extracellular signal-regulated kinase (ERK), cAMP response element-binding protein (CREB), brain-derived neurotrophic factor (BDNF) signaling in the nucleus accumbens (NAc) and hippocampus in morphine-induced conditioned place preference (CPP), which is used to assess the morphine-induced reward memory. The protein level of CB1R, ERK, CREB, and BDNF were detected by western blotting. Additionally, a CB1R antagonist, AM251, was used to study whether blockade of CB1R altered the CPP and above-mentioned molecules. We found an increase of CB1R expression in the NAc and hippocampus of the mice following morphine CPP, but not those after repeated morphine in home cage without context exposure (NO-CPP). Both morphine CPP and NO-CPP induced an upregulation of ERK, CREB phosphorylation and BDNF expression. Furthermore, pretreatment with AM251 before morphine attenuated the CPP acquisition and CB1R expression as well as the activation of ERK-CREB-BDNF cascade. Collectively, these findings demonstrate that (1) Repeated morphine with context exposures but not merely the pharmacological effects of morphine increased CB1R expression both in the NAc and hippocampus. (2) CB1R antagonist mediated blockade of ERK-CREB-BDNF signaling activation in the NAc and hippocampus may be an important mechanism underlying the attenuation of morphine CPP.

  11. Anandamide reverses depressive-like behavior, neurochemical abnormalities and oxidative-stress parameters in streptozotocin-diabetic rats: Role of CB1 receptors.

    Science.gov (United States)

    de Morais, Helen; de Souza, Camila P; da Silva, Luisa M; Ferreira, Daniele M; Baggio, Cristiane Hatsuko; Vanvossen, Ana Carolina; Cristina de Carvalho, Milene; da Silva-Santos, José Eduardo; Bertoglio, Leandro José; Cunha, Joice M; Zanoveli, Janaina M

    2016-10-01

    The pathophysiology associated with increased prevalence of depression in diabetics is not completely understood, although studies have pointed the endocannabinoid system as a possible target. Then, we aimed to investigate the role of this system in the pathophysiology of depression associated with diabetes. For this, diabetic (DBT) male Wistar rats were intraperitoneally treated with cannabinoid CB1 (AM251, 1mg/kg) or CB2 (AM630, 1mg/kg) receptor antagonists followed by anandamide (AEA, 0.005mg/kg) and then submitted to the forced swimming test (FST). Oxidative stress parameters, CB1 receptor expression and serotonin (5-HT) and noradrenaline levels in the hippocampus (HIP) and prefrontal cortex (PFC) were also performed. It was observed that DBT animals presented a more pronounced depressive-like behavior and increase of CB1 receptor expression in the HIP. AEA treatment induced a significant improvement in the depressive-like behavior, which was reversed by the CB1 antagonist AM251, without affecting the hyperglycemia or weight gain. AEA was also able to restore the elevated CB1 expression and also to elevate the reduced level of 5-HT in the HIP from DBT animals. In addition, AEA restored the elevated noradrenaline levels in the PFC and induced a neuroprotective effect by restoring the decreased reduced glutathione and increased lipid hydroperoxides levels along with the decreased superoxide dismutase activity observed in HIP or PFC. Together, our data suggest that in depression associated with diabetes, the endocannabinoid anandamide has a potential to induce neuroadaptative changes able to improve the depressive-like response by its action as a CB1 receptor agonist.

  12. CB1 cannabinoid receptors mediate endochondral skeletal growth attenuation by Δ9-tetrahydrocannabinol.

    Science.gov (United States)

    Wasserman, Elad; Tam, Joseph; Mechoulam, Raphael; Zimmer, Andreas; Maor, Gila; Bab, Itai

    2015-01-01

    The endocannabinoid (EC) system regulates bone mass. Because cannabis use during pregnancy results in stature shorter than normal, we examined the role of the EC system in skeletal elongation. We show that CB1 and CB2 cannabinoid receptors are expressed specifically in hypertrophic chondrocytes of the epiphyseal growth cartilage (EGC), which drives vertebrate growth. These cells also express diacylglycerol lipases, critical biosynthetic enzymes of the main EC, and 2-arachidonoylglycerol (2-AG), which is present at significant levels in the EGC. Femora of CB1- and/or CB2-deficient mice at the end of the rapid growth phase are longer compared to wild-type (WT) animals. We find that Δ(9) -tetrahydrocannabinol (THC) slows skeletal elongation of female WT and CB2-, but not CB1-, deficient mice, which is reflected in femoral and lumbar vertebral body length. This in turn results in lower body weight, but unaltered fat content. THC inhibits EGC chondrocyte hypertrophy in ex vivo cultures and reduces the hypertrophic cell zone thickness of CB1-, but not CB2-, deficient mice. These results demonstrate a local growth-restraining EC system in the EGC. The relevance of the present findings to humans remains to be studied.

  13. Expression and function of cannabinoid receptors CB1 and CB2 and their cognate cannabinoid ligands in murine embryonic stem cells.

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    Shuxian Jiang

    Full Text Available BACKGROUND: Characterization of intrinsic and extrinsic factors regulating the self-renewal/division and differentiation of stem cells is crucial in determining embryonic stem (ES cell fate. ES cells differentiate into multiple hematopoietic lineages during embryoid body (EB formation in vitro, which provides an experimental platform to define the molecular mechanisms controlling germ layer fate determination and tissue formation. METHODS AND FINDINGS: The cannabinoid receptor type 1 (CB1 and cannabinoid receptor type 2 (CB2 are members of the G-protein coupled receptor (GPCR family, that are activated by endogenous ligands, the endocannabinoids. CB1 receptor expression is abundant in brain while CB2 receptors are mostly expressed in hematopoietic cells. However, the expression and the precise roles of CB1 and CB2 and their cognate ligands in ES cells are not known. We observed significant induction of CB1 and CB2 cannabinoid receptors during the hematopoietic differentiation of murine ES (mES-derived embryoid bodies. Furthermore, mES cells as well as ES-derived embryoid bodies at days 7 and 14, expressed endocannabinoids, the ligands for both CB1 and CB2. The CB1 and CB2 antagonists (AM251 and AM630, respectively induced mES cell death, strongly suggesting that endocannabinoids are involved in the survival of mES cells. Treatment of mES cells with the exogenous cannabinoid ligand Delta(9-THC resulted in the increased hematopoietic differentiation of mES cells, while addition of AM251 or AM630 blocked embryoid body formation derived from the mES cells. In addition, cannabinoid agonists induced the chemotaxis of ES-derived embryoid bodies, which was specifically inhibited by the CB1 and CB2 antagonists. CONCLUSIONS: This work has not been addressed previously and yields new information on the function of cannabinoid receptors, CB1 and CB2, as components of a novel pathway regulating murine ES cell differentiation. This study provides insights

  14. Overexpression of cannabinoid receptors CB1 and CB2 correlates with improved prognosis of patients with hepatocellular carcinoma.

    Science.gov (United States)

    Xu, Xundi; Liu, Yi; Huang, Shengfu; Liu, Guoxing; Xie, Chengzhi; Zhou, Jun; Fan, Wentao; Li, Qinglong; Wang, Qunwei; Zhong, Dewu; Miao, Xiongying

    2006-11-01

    CB1 and CB2 are multifunctional cannabinoid-specific receptors considered to be involved in inhibition of tumor development. To elucidate their roles in hepatocarcinogenesis, we analyzed the expression of these receptors in tumor and matched nontumorous tissues of human hepatocellular carcinoma (HCC) samples. In situ hybridization analysis showed overexpression of CB1 mRNAs in 8 of 13 (62%) HCC samples, and of CB2 mRNAs in 7 of 13 (54%). Immunohistochemical analysis of 64 HCC samples showed the expression of CB1 and CB2 receptors to increase from normal liver to chronic hepatitis to cirrhosis. Marked expression of CB1 and CB2 receptors was noted in the majority of cirrhotic liver samples (86 and 78%, respectively). In HCC, high expression of CB1 and CB2 receptors was observed in 29 (45%) and 33 (52%) cases, respectively. Clinicopathological evaluation indicated a significant correlation between CB1 and CB2 expression and two clinicopathological parameters such as the histopathological differentiation (P = 0.021 and 0.001, respectively), portal vein invasion (P = 0.015 and 0.004, respectively). Univariate analysis indicated that disease-free survival was significantly better in HCC patients with high versus those with low CB1 and CB2 expression levels (P = 0.010 and 0.037, respectively). Our results indicate that CB1 and CB2 have potential as prognostic indicators and suggest possible beneficial effects of cannabinoids on prognosis of patients with HCC.

  15. Effects of Se-phenyl thiazolidine-4-carboselenoate on mechanical and thermal hyperalgesia in brachial plexus avulsion in mice: mediation by cannabinoid CB1 and CB2 receptors.

    Science.gov (United States)

    Del Fabbro, Lucian; Borges Filho, Carlos; Cattelan Souza, Leandro; Savegnago, Lucielli; Alves, Diego; Henrique Schneider, Paulo; de Salles, Helena Domingues; Jesse, Cristiano R

    2012-09-26

    In this study, we investigated the therapeutic effects of treatment with (R)-Se-phenyl thiazolidine-4-carboselenoate (Se-PTC), an organic selenium compound with antinociceptive properties, against mechanical and thermal hyperalgesia induced by brachial plexus avulsion (BPA), a neuropathic model in mice. The involvement of cannabinoid CB(1) and CB(2) receptors in the Se-PTC anti-hyperalgesic effect was also investigated. Se-PTC treatment at (25 and 50mg/kg, per oral, p.o.) lowered (BPA model) induced mechanical and thermal hyperalgesia in mice. Pretreatment with cannabinoid CB(1) (AM251; 1mg/kg, intraperitoneally, i.p.), or CB(2) (AM630; 3mg/kg, i.p.) receptor antagonists reverted the mechanical and thermal anti-hyperalgesic effect of Se-PTC (25mg/kg) in the BPA model. Selective CB(1) (ACEA, 10mg/kg, i.p.) and CB(2) (JWH-133, 10mg/kg, i.p.) receptor agonists lowered mechanical and thermal hyperalgesia in the BPA model, and this effect was prevented by selective CB(1) and CB(2) receptor antagonists. Gabapentin (70mg/kg, p.o.), positive control administration also lowered mechanical and thermal hyperalgesia in the BPA model. The results suggest that the mechanical and thermal hyperalgesia observed following BPA in mice is dependent on cannabinoid receptors. The results indicate that modulating cannabinoid receptors represent a valuable approach for the treatment of neuropathic pain. In conclusion, the results suggested that Se-PTC produces pronounced mechanical and thermal anti-hyperalgesic effects in neuropathic models in mice by modulating CB(1) and CB(2) receptors.

  16. Cognitive Impairment Induced by Delta9-tetrahydrocannabinol Occurs through Heteromers between Cannabinoid CB1 and Serotonin 5-HT2A Receptors.

    Science.gov (United States)

    Viñals, Xavier; Moreno, Estefanía; Lanfumey, Laurence; Cordomí, Arnau; Pastor, Antoni; de La Torre, Rafael; Gasperini, Paola; Navarro, Gemma; Howell, Lesley A; Pardo, Leonardo; Lluís, Carmen; Canela, Enric I; McCormick, Peter J; Maldonado, Rafael; Robledo, Patricia

    2015-07-01

    Activation of cannabinoid CB1 receptors (CB1R) by delta9-tetrahydrocannabinol (THC) produces a variety of negative effects with major consequences in cannabis users that constitute important drawbacks for the use of cannabinoids as therapeutic agents. For this reason, there is a tremendous medical interest in harnessing the beneficial effects of THC. Behavioral studies carried out in mice lacking 5-HT2A receptors (5-HT2AR) revealed a remarkable 5-HT2AR-dependent dissociation in the beneficial antinociceptive effects of THC and its detrimental amnesic properties. We found that specific effects of THC such as memory deficits, anxiolytic-like effects, and social interaction are under the control of 5-HT2AR, but its acute hypolocomotor, hypothermic, anxiogenic, and antinociceptive effects are not. In biochemical studies, we show that CB1R and 5-HT2AR form heteromers that are expressed and functionally active in specific brain regions involved in memory impairment. Remarkably, our functional data shows that costimulation of both receptors by agonists reduces cell signaling, antagonist binding to one receptor blocks signaling of the interacting receptor, and heteromer formation leads to a switch in G-protein coupling for 5-HT2AR from Gq to Gi proteins. Synthetic peptides with the sequence of transmembrane helices 5 and 6 of CB1R, fused to a cell-penetrating peptide, were able to disrupt receptor heteromerization in vivo, leading to a selective abrogation of memory impairments caused by exposure to THC. These data reveal a novel molecular mechanism for the functional interaction between CB1R and 5-HT2AR mediating cognitive impairment. CB1R-5-HT2AR heteromers are thus good targets to dissociate the cognitive deficits induced by THC from its beneficial antinociceptive properties.

  17. Cognitive Impairment Induced by Delta9-tetrahydrocannabinol Occurs through Heteromers between Cannabinoid CB1 and Serotonin 5-HT2A Receptors.

    Directory of Open Access Journals (Sweden)

    Xavier Viñals

    2015-07-01

    Full Text Available Activation of cannabinoid CB1 receptors (CB1R by delta9-tetrahydrocannabinol (THC produces a variety of negative effects with major consequences in cannabis users that constitute important drawbacks for the use of cannabinoids as therapeutic agents. For this reason, there is a tremendous medical interest in harnessing the beneficial effects of THC. Behavioral studies carried out in mice lacking 5-HT2A receptors (5-HT2AR revealed a remarkable 5-HT2AR-dependent dissociation in the beneficial antinociceptive effects of THC and its detrimental amnesic properties. We found that specific effects of THC such as memory deficits, anxiolytic-like effects, and social interaction are under the control of 5-HT2AR, but its acute hypolocomotor, hypothermic, anxiogenic, and antinociceptive effects are not. In biochemical studies, we show that CB1R and 5-HT2AR form heteromers that are expressed and functionally active in specific brain regions involved in memory impairment. Remarkably, our functional data shows that costimulation of both receptors by agonists reduces cell signaling, antagonist binding to one receptor blocks signaling of the interacting receptor, and heteromer formation leads to a switch in G-protein coupling for 5-HT2AR from Gq to Gi proteins. Synthetic peptides with the sequence of transmembrane helices 5 and 6 of CB1R, fused to a cell-penetrating peptide, were able to disrupt receptor heteromerization in vivo, leading to a selective abrogation of memory impairments caused by exposure to THC. These data reveal a novel molecular mechanism for the functional interaction between CB1R and 5-HT2AR mediating cognitive impairment. CB1R-5-HT2AR heteromers are thus good targets to dissociate the cognitive deficits induced by THC from its beneficial antinociceptive properties.

  18. CB1 cannabinoid receptor in SF1-expressing neurons of the ventromedial hypothalamus determines metabolic responses to diet and leptin.

    Science.gov (United States)

    Cardinal, Pierre; André, Caroline; Quarta, Carmelo; Bellocchio, Luigi; Clark, Samantha; Elie, Melissa; Leste-Lasserre, Thierry; Maitre, Marlene; Gonzales, Delphine; Cannich, Astrid; Pagotto, Uberto; Marsicano, Giovanni; Cota, Daniela

    2014-10-01

    Metabolic flexibility allows rapid adaptation to dietary change, however, little is known about the CNS mechanisms regulating this process. Neurons in the hypothalamic ventromedial nucleus (VMN) participate in energy balance and are the target of the metabolically relevant hormone leptin. Cannabinoid type-1 (CB1) receptors are expressed in VMN neurons, but the specific contribution of endocannabinoid signaling in this neuronal population to energy balance regulation is unknown. Here we demonstrate that VMN CB1 receptors regulate metabolic flexibility and actions of leptin. In chow-fed mice, conditional deletion of CB1 in VMN neurons (expressing the steroidogenic factor 1, SF1) decreases adiposity by increasing sympathetic activity and lipolysis, and facilitates metabolic effects of leptin. Conversely, under high-fat diet, lack of CB1 in VMN neurons produces leptin resistance, blunts peripheral use of lipid substrates and increases adiposity. Thus, CB1 receptors in VMN neurons provide a molecular switch adapting the organism to dietary change.

  19. CB1 cannabinoid receptor in SF1-expressing neurons of the ventromedial hypothalamus determines metabolic responses to diet and leptin

    Directory of Open Access Journals (Sweden)

    Pierre Cardinal

    2014-10-01

    Full Text Available Metabolic flexibility allows rapid adaptation to dietary change, however, little is known about the CNS mechanisms regulating this process. Neurons in the hypothalamic ventromedial nucleus (VMN participate in energy balance and are the target of the metabolically relevant hormone leptin. Cannabinoid type-1 (CB1 receptors are expressed in VMN neurons, but the specific contribution of endocannabinoid signaling in this neuronal population to energy balance regulation is unknown. Here we demonstrate that VMN CB1 receptors regulate metabolic flexibility and actions of leptin. In chow-fed mice, conditional deletion of CB1 in VMN neurons (expressing the steroidogenic factor 1, SF1 decreases adiposity by increasing sympathetic activity and lipolysis, and facilitates metabolic effects of leptin. Conversely, under high-fat diet, lack of CB1 in VMN neurons produces leptin resistance, blunts peripheral use of lipid substrates and increases adiposity. Thus, CB1 receptors in VMN neurons provide a molecular switch adapting the organism to dietary change.

  20. Detection of cannabinoid receptors CB1 and CB2 within basal ganglia output neurons in macaques: changes following experimental parkinsonism.

    Science.gov (United States)

    Sierra, Salvador; Luquin, Natasha; Rico, Alberto J; Gómez-Bautista, Virginia; Roda, Elvira; Dopeso-Reyes, Iria G; Vázquez, Alfonso; Martínez-Pinilla, Eva; Labandeira-García, José L; Franco, Rafael; Lanciego, José L

    2015-09-01

    Although type 1 cannabinoid receptors (CB1Rs) are expressed abundantly throughout the brain, the presence of type 2 cannabinoid receptors (CB2Rs) in neurons is still somewhat controversial. Taking advantage of newly designed CB1R and CB2R mRNA riboprobes, we demonstrate by PCR and in situ hybridization that transcripts for both cannabinoid receptors are present within labeled pallidothalamic-projecting neurons of control and MPTP-treated macaques, whereas the expression is markedly reduced in dyskinetic animals. Moreover, an in situ proximity ligation assay was used to qualitatively assess the presence of CB1Rs and CB2Rs, as well as CB1R-CB2R heteromers within basal ganglia output neurons in all animal groups (control, parkinsonian and dyskinetic macaques). A marked reduction in the number of CB1Rs, CB2Rs and CB1R-CB2R heteromers was found in dyskinetic animals, mimicking the observed reduction in CB1R and CB2R mRNA expression levels. The fact that chronic levodopa treatment disrupted CB1R-CB2R heteromeric complexes should be taken into consideration when designing new drugs acting on cannabinoid receptor heteromers.

  1. Reduced neural response to reward following 7 days treatment with the cannabinoid CB1 antagonist rimonabant in healthy volunteers.

    Science.gov (United States)

    Horder, Jamie; Harmer, Catherine J; Cowen, Philip J; McCabe, Ciara

    2010-09-01

    Reduced subjective experience of reward (anhedonia) is a key symptom of major depression. The anti-obesity drug and cannabinoid type 1 receptor (CB(1)) antagonist, rimonabant, is associated with significant rates of depression and anxiety in clinical use and was recently withdrawn from the market because of these adverse effects. Using a functional magnetic resonance imaging (fMRI) model of reward we hypothesized that rimonabant would impair reward processing. Twenty-two healthy participants were randomly allocated to receive rimonabant (20 mg), or placebo, for 7 d in a double-blind, parallel group design. We used fMRI to measure the neural response to rewarding (sight and/or flavour of chocolate) and aversive (sight of mouldy strawberries and/or an unpleasant strawberry taste) stimuli on the final day of drug treatment. Rimonabant reduced the neural response to chocolate stimuli in key reward areas such as the ventral striatum and the orbitofrontal cortex. Rimonabant also decreased neural responses to the aversive stimulus condition in the caudate nucleus and ventral striatum, but increased lateral orbitofrontal activations to the aversive sight and taste of strawberry condition. Our findings are the first to show that the anti-obesity drug rimonabant inhibits the neural processing of rewarding food stimuli in humans. This plausibly underlies its ability to promote weight loss, but may also indicate a mechanism for inducing anhedonia which could lead to the increased risk of depressive symptomatology seen in clinical use. fMRI may be a useful method of screening novel agents for unwanted effects on reward and associated clinical adverse reactions.

  2. Anti Proliferative and Pro Apoptotic Effects of Flavonoid Quercetin Are Mediated by CB1 Receptor in Human Colon Cancer Cell Lines.

    Science.gov (United States)

    Refolo, Maria Grazia; D'Alessandro, Rosalba; Malerba, Natascia; Laezza, Chiara; Bifulco, Maurizio; Messa, Caterina; Caruso, Maria Gabriella; Notarnicola, Maria; Tutino, Valeria

    2015-12-01

    Quercetin, the major constituent of flavonoid and widely present in fruits and vegetables, is an attractive compound for cancer prevention due to its beneficial anti proliferative effects, showing a crucial role in the regulation of apoptosis and cell cycle signaling. In vitro studies have demonstrated that quercetin specifically influences colon cancer cell proliferation. Our experiments, using human colon adenocarcinoma cells, confirmed the anti proliferative effect of quercetin and gave intriguing new insight in to the knowledge of the mechanisms involved. We observed a significant increase in the expression of the endocannabinoids receptor (CB1-R) after quercetin treatment. CB1-R can be considered an estrogen responsive receptor and quercetin, having a structure similar to that of the estrogens, can interact with CB1-R leading to the regulation of cell growth. In order to clarify the contribution of the CB1-R to the quercetin action, we investigated some of the principal molecular pathways that are inhibited or activated by this natural compound. In particular we detected the inhibition of the major survival signals like the PI3K/Akt/mTOR and an induction of the pro apoptotic JNK/JUN pathways. Interestingly, the metabolism of β-catenin was modified by flavonoid both directly and through activated CB1-R. In all the experiments done, the quercetin action has proven to be reinforced by anandamide (Met-F-AEA), a CB1-R agonist, and partially counteracted by SR141716, a CB1-R antagonist. These findings open new perspectives for anticancer therapeutic strategies.

  3. A Cannabinoid CB1 Receptor-Positive Allosteric Modulator Reduces Neuropathic Pain in the Mouse with No Psychoactive Effects.

    Science.gov (United States)

    Ignatowska-Jankowska, Bogna M; Baillie, Gemma L; Kinsey, Steven; Crowe, Molly; Ghosh, Sudeshna; Owens, Robert A; Damaj, Imad M; Poklis, Justin; Wiley, Jenny L; Zanda, Matteo; Zanato, Chiara; Greig, Iain R; Lichtman, Aron H; Ross, Ruth A

    2015-12-01

    The CB1 receptor represents a promising target for the treatment of several disorders including pain-related disease states. However, therapeutic applications of Δ(9)-tetrahydrocannabinol and other CB1 orthosteric receptor agonists remain limited because of psychoactive side effects. Positive allosteric modulators (PAMs) offer an alternative approach to enhance CB1 receptor function for therapeutic gain with the promise of reduced side effects. Here we describe the development of the novel synthetic CB1 PAM, 6-methyl-3-(2-nitro-1-(thiophen-2-yl)ethyl)-2-phenyl-1H-indole (ZCZ011), which augments the in vitro and in vivo pharmacological actions of the CB1 orthosteric agonists CP55,940 and N-arachidonoylethanolamine (AEA). ZCZ011 potentiated binding of [(3)H]CP55,940 to the CB1 receptor as well as enhancing AEA-stimulated [(35)S]GTPγS binding in mouse brain membranes and β-arrestin recruitment and ERK phosphorylation in hCB1 cells. In the whole animal, ZCZ011 is brain penetrant, increased the potency of these orthosteric agonists in mouse behavioral assays indicative of cannabimimetic activity, including antinociception, hypothermia, catalepsy, locomotor activity, and in the drug discrimination paradigm. Administration of ZCZ011 alone was devoid of activity in these assays and did not produce a conditioned place preference or aversion, but elicited CB1 receptor-mediated antinociceptive effects in the chronic constriction nerve injury model of neuropathic pain and carrageenan model of inflammatory pain. These data suggest that ZCZ011 acts as a CB1 PAM and provide the first proof of principle that CB1 PAMs offer a promising strategy to treat neuropathic and inflammatory pain with minimal or no cannabimimetic side effects.

  4. Opposite changes in cannabinoid CB1 and CB2 receptor expression in human gliomas.

    Science.gov (United States)

    De Jesús, Maider López; Hostalot, Cristina; Garibi, Jesús M; Sallés, Joan; Meana, J Javier; Callado, Luis F

    2010-01-01

    Gliomas are the most important group of malignant primary brain tumors and one of the most aggressive forms of cancer. During the last years, several studies have demonstrated that cannabinoids induce apoptosis of glioma cells and inhibit angiogenesis of gliomas in vivo. As the effects of cannabinoids rely on CB(1) and CB(2) receptors activation, the aim of the present study was to investigate both receptors protein expression in cellular membrane homogenates of human glial tumors using specific antibodies raised against these proteins. Additionally, we studied the functionality of the cannabinoid receptors in glioblastomas by using WIN 55,212-2 stimulated [(35)S]GTPgammaS binding. Western blot analysis showed that CB(1) receptor immunoreactivity was significantly lower in glioblastoma multiforme (-43%, n=10; p<0.05) than in normal post-mortem brain tissue (n=16). No significant differences were found for astrocytoma (n=6) and meningioma (n=8) samples. Conversely, CB(2) receptor immunoreactivity was significantly greater in membranes of glioblastoma multiforme (765%, n=9; p<0.05) and astrocytoma (471%, n=4; p<0.05) than in control brain tissue (n=10). Finally, the maximal stimulation of [(35)S]GTPgammaS binding by WIN 55,212-2 was significantly lower in glioblastomas (134+/-4%) than in control membranes (183+/-2%; p<0.05). The basal [(35)S]GTPgammaS binding and the EC(50) values were not significantly different between both groups. The present results demonstrate opposite changes in CB(1) and CB(2) receptor protein expression in human gliomas. These changes may be of interest for further research about the therapeutic effects of cannabinoids in glial tumors.

  5. Detection of cannabinoid receptors CB1 and CB2 within basal ganglia output neurons in macaques: changes following experimental parkinsonism

    OpenAIRE

    S. Sierra; Luquin, N. (Natasha); Rico, A.J. (Alberto J.); Gomez-Bautista, V. (V.); Roda, E.; Dopeso-Reyes, I. G.; Vazquez, A.; Martinez-Pinilla, E. (Eva); Labandeira-Garcia, J.L. (José L.); Franco, R; J.L. Lanciego

    2014-01-01

    Abstract Although type 1 cannabinoid receptors (CB1- Rs) are expressed abundantly throughout the brain, the presence of type 2 cannabinoid receptors (CB2Rs) in neurons is still somewhat controversial. Taking advantage of newly designed CB1R and CB2R mRNA riboprobes, we demonstrate by PCR and in situ hybridization that transcripts for both cannabinoid receptors are present within labeled pallidothalamic-projecting neurons of control and MPTP-treated macaques, whereas th...

  6. The Expression Level of CB1 and CB2 Receptors Determines Their Efficacy at Inducing Apoptosis in Astrocytomas

    OpenAIRE

    Eiron Cudaback; William Marrs; Thomas Moeller; Nephi Stella

    2010-01-01

    BACKGROUND: Cannabinoids represent unique compounds for treating tumors, including astrocytomas. Whether CB(1) and CB(2) receptors mediate this therapeutic effect is unclear. PRINCIPAL FINDINGS: We generated astrocytoma subclones that express set levels of CB(1) and CB(2), and found that cannabinoids induce apoptosis only in cells expressing low levels of receptors that couple to ERK1/2. In contrast, cannabinoids do not induce apoptosis in cells expressing high levels of receptors because the...

  7. Comparative effects of chlorpyrifos in wild type and cannabinoid Cb1 receptor knockout mice

    Energy Technology Data Exchange (ETDEWEB)

    Baireddy, Praveena; Liu, Jing; Hinsdale, Myron; Pope, Carey, E-mail: carey.pope@okstate.edu

    2011-11-15

    Endocannabinoids (eCBs) modulate neurotransmission by inhibiting the release of a variety of neurotransmitters. The cannabinoid receptor agonist WIN 55.212-2 (WIN) can modulate organophosphorus (OP) anticholinesterase toxicity in rats, presumably by inhibiting acetylcholine (ACh) release. Some OP anticholinesterases also inhibit eCB-degrading enzymes. We studied the effects of the OP insecticide chlorpyrifos (CPF) on cholinergic signs of toxicity, cholinesterase activity and ACh release in tissues from wild type (+/+) and cannabinoid CB1 receptor knockout (-/-) mice. Mice of both genotypes (n = 5-6/treatment group) were challenged with CPF (300 mg/kg, 2 ml/kg in peanut oil, sc) and evaluated for functional and neurochemical changes. Both genotypes exhibited similar cholinergic signs and cholinesterase inhibition (82-95% at 48 h after dosing) in cortex, cerebellum and heart. WIN reduced depolarization-induced ACh release in vitro in hippocampal slices from wild type mice, but had no effect in hippocampal slices from knockouts or in striatal slices from either genotype. Chlorpyrifos oxon (CPO, 100 {mu}M) reduced release in hippocampal slices from both genotypes in vitro, but with a greater reduction in tissues from wild types (21% vs 12%). CPO had no significant in vitro effect on ACh release in striatum. CPF reduced ACh release in hippocampus from both genotypes ex vivo, but reduction was again significantly greater in tissues from wild types (52% vs 36%). In striatum, CPF led to a similar reduction (20-23%) in tissues from both genotypes. Thus, while CB1 deletion in mice had little influence on the expression of acute toxicity following CPF, CPF- or CPO-induced changes in ACh release appeared sensitive to modulation by CB1-mediated eCB signaling in a brain-regional manner. -- Highlights: Black-Right-Pointing-Pointer C57Bl/6 mice showed dose-related cholinergic toxicity following subcutaneous chlorpyrifos exposure. Black-Right-Pointing-Pointer Wild type and

  8. Molecular basis of cannabinoid CB1 receptor coupling to the G protein heterotrimer Gαiβγ: identification of key CB1 contacts with the C-terminal helix α5 of Gαi.

    Science.gov (United States)

    Shim, Joong-Youn; Ahn, Kwang H; Kendall, Debra A

    2013-11-01

    The cannabinoid (CB1) receptor is a member of the rhodopsin-like G protein-coupled receptor superfamily. The human CB1 receptor, which is among the most expressed receptors in the brain, has been implicated in several disease states, including drug addiction, anxiety, depression, obesity, and chronic pain. Different classes of CB1 agonists evoke signaling pathways through the activation of specific subtypes of G proteins. The molecular basis of CB1 receptor coupling to its cognate G protein is unknown. As a first step toward understanding CB1 receptor-mediated G protein signaling, we have constructed a ternary complex structural model of the CB1 receptor and Gi heterotrimer (CB1-Gi), guided by the x-ray structure of β2-adrenergic receptor (β2AR) in complex with Gs (β2AR-Gs), through 824-ns duration molecular dynamics simulations in a fully hydrated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayer environment. We identified a group of residues at the juxtamembrane regions of the intracellular loops 2 and 3 (IC2 and IC3) of the CB1 receptor, including Ile-218(3.54), Tyr-224(IC2), Asp-338(6.30), Arg-340(6.32), Leu-341(6.33), and Thr-344(6.36), as potential key contacts with the extreme C-terminal helix α5 of Gαi. Ala mutations of these residues at the receptor-Gi interface resulted in little G protein coupling activity, consistent with the present model of the CB1-Gi complex, which suggests tight interactions between CB1 and the extreme C-terminal helix α5 of Gαi. The model also suggests that unique conformational changes in the extreme C-terminal helix α5 of Gα play a crucial role in the receptor-mediated G protein activation.

  9. Inhibitory effects of CB1 and CB2 receptor agonists on responses of DRG neurons and dorsal horn neurons in neuropathic rats.

    Science.gov (United States)

    Sagar, Devi Rani; Kelly, Sara; Millns, Paul J; O'Shaughnessey, Celestine T; Kendall, David A; Chapman, Victoria

    2005-07-01

    Cannabinoid 2 (CB2) receptor mediated antinociception and increased levels of spinal CB2 receptor mRNA are reported in neuropathic Sprague-Dawley rats. The aim of this study was to provide functional evidence for a role of peripheral, vs. spinal, CB2 and cannabinoid 1 (CB1) receptors in neuropathic rats. Effects of the CB2 receptor agonist, JWH-133, and the CB1 receptor agonist, arachidonyl-2-chloroethylamide (ACEA), on primary afferent fibres were determined by calcium imaging studies of adult dorsal root ganglion (DRG) neurons taken from neuropathic and sham-operated rats. Capsaicin (100 nm) increased [Ca2+]i in DRG neurons from sham and neuropathic rats. JWH-133 (3 microm) or ACEA (1 microm) significantly (PCB2 receptor antagonist, SR144528, (1 microm) significantly inhibited the effects of JWH-133. Effects of ACEA were significantly inhibited by the CB1 receptor antagonist SR141716A (1 microm). In vivo experiments evaluated the effects of spinal administration of JWH-133 (8-486 ng/50 microL) and ACEA (0.005-500 ng/50 microL) on mechanically evoked responses of neuropathic and sham-operated rats. Spinal JWH-133 attenuated mechanically evoked responses of spinal neurons in neuropathic, but not sham-operated rats. These inhibitory effects were blocked by SR144528 (0.001 microg/50 microL). Spinal ACEA inhibited mechanically evoked responses of neuropathic and sham-operated rats, these effects were blocked by SR141716A (0.01 microg/50 microL). Our data provide evidence for a functional role of CB2, as well as CB1 receptors on DRG neurons in sham and neuropathic rats. At the level of the spinal cord, CB2 receptors have inhibitory effects in neuropathic, but not sham-operated rats suggesting that spinal CB2 may be an important analgesic target.

  10. The CB1/CB2 receptor agonist WIN-55,212-2 reduces viability of human Kaposi's sarcoma cells in vitro.

    Science.gov (United States)

    Luca, Tonia; Di Benedetto, Giulia; Scuderi, Mariagrazia Rita; Palumbo, Marco; Clementi, Silvia; Bernardini, Renato; Cantarella, Giuseppina

    2009-08-15

    Kaposi's sarcoma is a highly vascularized mesenchymal neoplasm arising with multiple lesions of the skin. Endogenous cannabinoids have been shown to inhibit proliferation of a wide spectrum of tumor cells. We studied the effects of cannabinoids on human Kaposi's sarcoma cell proliferation in vitro. To do so, we first investigated the presence of the cannabinoid receptors CB(1) and CB(2) mRNAs in the human Kaposi's sarcoma cell line KS-IMM by RT-PCR and, subsequently, the effects of the mixed CB(1)/CB(2) agonist WIN-55,212-2 (WIN) on cell proliferation in vitro. WIN showed antimitogenic effects on Kaposi's sarcoma cells. Western blot analysis of Kaposi's sarcoma lysates suggested that WIN treatment induced activation of both caspase-3 and -6, as well as increased phosphorylation of the stress kinase p38 and JNK, along with transient phosphorylation of ERK(1/2). To better characterize the involvement of each single CB receptor in cannabinoid-induced cell death, we incubated Kaposi's sarcoma cells with different selective cannabinoid receptor agonists, respectively ACEA (CB(1)) and JWH-133 (CB(2)). None of the agonists was able to induce KS-IMM cell apoptosis. Moreover, we co-incubated Kaposi's sarcoma cells with WIN-55,212-2 and either the CB(1) receptor antagonist AM251, the CB(2) receptor antagonist AM630, or a combination of both substances. The CB(2) receptor antagonist AM630 was able to significantly increase survival of Kaposi's sarcoma cells treated with WIN. In view of the antiproliferative effects of cannabinoids on KS-IMM cells, one could envision the cannabinoid system as a potential target for pharmacological treatment of Kaposi's sarcoma.

  11. Unbalance of CB1 receptors expressed in GABAergic and glutamatergic neurons in a transgenic mouse model of Huntington's disease.

    Science.gov (United States)

    Chiodi, Valentina; Uchigashima, Motokazu; Beggiato, Sarah; Ferrante, Antonella; Armida, Monica; Martire, Alberto; Potenza, Rosa Luisa; Ferraro, Luca; Tanganelli, Sergio; Watanabe, Masahiko; Domenici, Maria Rosaria; Popoli, Patrizia

    2012-03-01

    Cannabinoid CB1 receptors (CB1Rs) are known to be downregulated in patients and in animal models of Huntington's disease (HD). However, the functional meaning of this reduction, if any, is still unclear. Here, the effects of the cannabinoid receptor agonist WIN 55,212-2 (WIN) were investigated on striatal synaptic transmission and on glutamate and GABA release in symptomatic R6/2 mice, a genetic model of HD. The expression levels of CB1Rs in glutamatergic and GABAergic synapses were also evaluated. We found that in R6/2 mice, WIN effects on synaptic transmission and glutamate release were significantly increased with respect to wild type mice. On the contrary, a decrease in WIN-induced reduction of GABA release was found in R6/2 versus WT mice. The expression of CB1Rs in GABAergic neurons was drastically reduced, while CB1Rs levels in glutamatergic neurons were unchanged. These results demonstrate that the expression and functionality of CB1Rs are differentially affected in GABAergic and glutamatergic neurons in R6/2 mice. As a result, the balance between CB1Rs expressed by the two neuronal populations and, thus, the net effect of CB1R stimulation, is profoundly altered in HD mice.

  12. Cannabinoid receptor CB1 regulates STAT3 activity and its expression dictates the responsiveness to SR141716 treatment in human glioma patients' cells.

    Science.gov (United States)

    Ciaglia, Elena; Torelli, Giovanni; Pisanti, Simona; Picardi, Paola; D'Alessandro, Alba; Laezza, Chiara; Malfitano, Anna Maria; Fiore, Donatella; Pagano Zottola, Antonio Christian; Proto, Maria Chiara; Catapano, Giuseppe; Gazzerro, Patrizia; Bifulco, Maurizio

    2015-06-20

    Herein we show that a majority of human brain tumor samples and cell lines over-expressed cannabinoid receptor CB1 as compared to normal human astrocytes (NHA), while uniformly expressed low levels of CB2. This finding prompted us to investigate the therapeutic exploitation of CB1 inactivation by SR141716 treatment, with regard to its direct and indirect cell-mediated effects against gliomas. Functional studies, using U251MG glioma cells and primary tumor cell lines derived from glioma patients expressing different levels of CB1, highlighted SR141716 efficacy in inducing apoptosis via G1 phase stasis and block of TGF-β1 secretion through a mechanism that involves STAT3 inhibition. According to the multivariate role of STAT3 in the immune escape too, interestingly SR141716 lead also to the functional and selective expression of MICA/B on the surface of responsive malignant glioma cells, but not on NHA. This makes SR141716 treated-glioma cells potent targets for allogeneic NK cell-mediated recognition through a NKG2D restricted mechanism, thus priming them for NK cell antitumor reactivity. These results indicate that CB1 and STAT3 participate in a new oncogenic network in the complex biology of glioma and their expression levels in patients dictate the efficacy of the CB1 antagonist SR141716 in multimodal glioma destruction.

  13. Involvement of CB1 and CB2 receptors in the modulation of cholinergic neurotransmission in mouse gastric preparations.

    Science.gov (United States)

    Mulè, Flavia; Amato, Antonella; Baldassano, Sara; Serio, Rosa

    2007-09-01

    While most of the studies concerning the role of cannabinoids on gastric motility have focused the attention on the gastric emptying in in vivo animal models, there is little information about the cannabinoid peripheral influence in the stomach. In addition, the functional features of CB2 receptors in the gastrointestinal tract have been poorly characterized. The purpose of the present study was to investigate the effects of cannabinoid drugs on the excitatory cholinergic and inhibitory non-adrenergic non-cholinergic (NANC) neurotransmission in mouse isolated gastric preparations. Intraluminal pressure from isolated whole stomach was recorded and mechanical responses induced by electrical field stimulation (EFS) were analyzed in different experimental conditions. EFS (0.5ms duration, supramaximal voltage, in trains of 5s, 2-16Hz) caused a cholinergic contraction, which was abolished by atropine or tetrodotoxin (TTX). The cannabinoid receptor agonist, WIN 55,212-2, the endogenous ligand, anandamide, the selective CB1 receptor agonist ACEA, and the selective CB2 receptor agonists, JWH015 and JWH133, produced a concentration-dependent reduction of the EFS-evoked cholinergic contractions. SR141716A, CB1 receptor antagonist, significantly attenuated the inhibitory effects induced by WIN 55,212-2, anandamide or ACEA, without affecting those caused by JWH133. AM630, CB2 receptor antagonist, reduced the inhibitory effects induced by WIN 55,212-2, anandamide, JWH015 or JWH133, without affecting those caused by ACEA. The joint application of SR141716A and AM630 was able of fully preventing the WIN 55,212-2 and anandamide actions. The cannabinoid antagonists failed per se to affect the neurally evoked responses. Cannabinoids did not modify the contractions produced by exogenous carbachol. In the presence of atropine and guanethidine (NANC conditions) EFS-induced TTX-sensitive relaxation consisting in an early and rapid component followed by a second slow phase, which were

  14. Inhibition of spontaneous neurotransmission in the nucleus of solitary tract of the rat by the cannabinoid agonist WIN 55212-2 is not via CB1 or CB2 receptors.

    Science.gov (United States)

    Accorsi-Mendonça, Daniela; Almado, Carlos E L; Dagostin, André L A; Machado, Benedito H; Leão, Ricardo M

    2008-03-20

    Cannabinoids have been shown to modulate central autonomic regulation and baroreflex control of blood pressure. Both CB1 and CB2 cannabinoid receptors have been described in the nucleus tractus solitarius (NTS), which receives direct afferent projections of cardiovascular reflexes. In the present study we evaluated the effects of WIN 55212-2 (WIN), a cannabinoid agonist, on fast neurotransmission in the NTS. We recorded spontaneous post-synaptic currents using the whole-cell configuration in NTS cells in brainstem slices from young rats (25-30 days old). Application of 5 microM WIN inhibited the frequency of both glutamatergic and GABAergic sPSCs, without affecting their amplitudes. Effects of WIN were not blocked by application of the CB1 antagonist AM251, the CB2 antagonist AM630 or the vanniloid receptor TRPV1 antagonist AMG9810, suggesting that the effect of WIN is via a non-CB1 non-CB2 receptor. Neither the CB1/CB2 agonist HU210 nor the CB1 agonist ACPA affected the frequency of sPSCs. We conclude WIN inhibits the neurotransmission in the NTS of young rats via a receptor distinct from CB1 or CB2.

  15. Altered expression of the CB1 cannabinoid receptor in the triple transgenic mouse model of Alzheimer's disease.

    Science.gov (United States)

    Bedse, Gaurav; Romano, Adele; Cianci, Silvia; Lavecchia, Angelo M; Lorenzo, Pace; Elphick, Maurice R; Laferla, Frank M; Vendemiale, Gianluigi; Grillo, Caterina; Altieri, Fabio; Cassano, Tommaso; Gaetani, Silvana

    2014-01-01

    The endocannabinoid system has gained much attention as a new potential pharmacotherapeutic target in various neurodegenerative diseases, including Alzheimer's disease (AD). However, the association between CB1 alterations and the development of AD neuropathology is unclear and often contradictory. In this study, brain CB1 mRNA and CB1 protein levels were analyzed in 3 × Tg-AD mice and compared to wild-type littermates at 2, 6 and 12 months of age, using in-situ hybridization and immunohistochemistry, respectively. Semiquantitative analysis of CB1 expression focused on the prefrontal cortex (PFC), prelimbic cortex, dorsal hippocampus (DH), basolateral amygdala complex (BLA), and ventral hippocampus (VH), all areas with high CB1 densities that are strongly affected by neuropathology in 3 × Tg-AD mice. At 2 months of age, there was no change in CB1 mRNA and protein levels in 3 × Tg-AD mice compared to Non-Tg mice in all brain areas analyzed. However, at 6 and 12 months of age, CB1 mRNA levels were significantly higher in PFC, DH, and BLA, and lower in VH in 3 × Tg-AD mice compared to wild-type littermates. CB1 immunohistochemistry revealed that CB1 protein expression was unchanged in 3 × Tg-AD at 2 and 6 months of age, while a significant decrease in CB1 receptor immunoreactivity was detected in the BLA and DH of 12-month-old 3 × Tg-AD mice, with no sign of alteration in other brain areas. The altered CB1 levels appear, rather, to be age-and/or pathology-dependent, indicating an involvement of the endocannabinoid system in AD pathology and supporting the ECS as a potential novel therapeutic target for treatment of AD.

  16. Contrasting effects of lithium chloride and CB1 receptor blockade on enduring changes in the valuation of reward.

    Directory of Open Access Journals (Sweden)

    Giovanni eHernandez

    2011-09-01

    Full Text Available When an organism has been trained to respond for a reward, its learned behavior can be characterized as goal-directed or habitual based on whether or not it is susceptible to reward devaluation. Here, we evaluated whether instrumental responding for brain stimulation reward (BSR can devalued using a paradigm traditionally used for natural rewards. Rats were trained to lever press for BSR. Subsequently, BSR was paired with either lithium chloride (LiCl, 5 mg/kg, i.p, a pro-emetic, or AM251, a CB1 receptor antagonist (3 mg/kg, i.p.. Pairings of BSR with these two compounds or their respective vehicle were performed in a novel environment so that only unconditional effects of BSR were affected by the pharmacological manipulations. Subsequently, in a probe test, all rats were returned in the drug-free state to the boxes where they had received training instrumental responding was reassessed in the absence of BSR delivery. LiCl produced enduring decreases in the number of responses during the test session, whereas AM251 had no effect. These results show that instrumental responding for BSR is susceptible to devaluation, in accord with the proposal that this behavior is supported at least in part by associations between the response and the rewarding outcome. Furthermore, they suggest that the reward modulation observed in studies involving the use of CB1 receptor antagonists arises from changes in the organism’s motivation rather than due to drug-induced changes in the intrinsic value of reward.

  17. Involvement of CB1 receptors in the ventral tegmental area in the potentiation of morphine rewarding properties in acquisition but not expression in the conditioned place preference model.

    Science.gov (United States)

    Rashidy-Pour, Ali; Pahlevani, Pouyan; Vaziri, Anoumid; Shaigani, Pariya; Zarepour, Leila; Vafaei, Abbas Ali; Haghparast, Abbas

    2013-06-15

    The ventral tegmental area (VTA) is a critical part of the brain reward system and has been engaged in mediating rewarding actions. CB1 receptors are one of the receptors that mediate the actions of cannabinoids and endocannabinoids in the central nervous system. Our aim was to determine the potentiating effects of CB1 receptors within the VTA in the acquisition and expression of morphine conditioned place preference (CPP). Stereotaxic surgery was performed bilaterally on each rat to administrate WIN55,212-2 (1, 2 and 4 mmol/0.3 μl DMSO) as CB1 receptor agonist and AM251 (15, 45 and 90 mmol/0.3 μl DMSO) as CB1 receptor antagonist. A three-compartment apparatus was used for the CPP test. The results showed that two doses of WIN55,212-2 (2 and 4 mmol) potentiates the rewarding effects of ineffective dose of morphine (2 mg/kg). We did not see any significant difference between any other doses of WIN55,212-2 and vehicle in the group which received the effective dose of morphine (5mg/kg). Additionally, conditioning scores decreased significantly with the highest administrated dose of AM251 (90 mmol) compared to the vehicle group. We did not observe any significant differences in the experiments for CPP expression by WIN55,212-2 or AM251. It seems that the cannabinoid and opioid systems are in interaction with each other and affect dopaminergic and/or non-dopaminergic neurons in the VTA. Blockade of CB1 receptors may increase GABA release, resulting in the reduction of dopamine output followed by a decrease in the acquisition of morphine-induced CPP in rats.

  18. Prenatal exposure to cannabinoids evokes long-lasting functional alterations by targeting CB1 receptors on developing cortical neurons.

    Science.gov (United States)

    de Salas-Quiroga, Adán; Díaz-Alonso, Javier; García-Rincón, Daniel; Remmers, Floortje; Vega, David; Gómez-Cañas, María; Lutz, Beat; Guzmán, Manuel; Galve-Roperh, Ismael

    2015-11-03

    The CB1 cannabinoid receptor, the main target of Δ(9)-tetrahydrocannabinol (THC), the most prominent psychoactive compound of marijuana, plays a crucial regulatory role in brain development as evidenced by the neurodevelopmental consequences of its manipulation in animal models. Likewise, recreational cannabis use during pregnancy affects brain structure and function of the progeny. However, the precise neurobiological substrates underlying the consequences of prenatal THC exposure remain unknown. As CB1 signaling is known to modulate long-range corticofugal connectivity, we analyzed the impact of THC exposure on cortical projection neuron development. THC administration to pregnant mice in a restricted time window interfered with subcerebral projection neuron generation, thereby altering corticospinal connectivity, and produced long-lasting alterations in the fine motor performance of the adult offspring. Consequences of THC exposure were reminiscent of those elicited by CB1 receptor genetic ablation, and CB1-null mice were resistant to THC-induced alterations. The identity of embryonic THC neuronal targets was determined by a Cre-mediated, lineage-specific, CB1 expression-rescue strategy in a CB1-null background. Early and selective CB1 reexpression in dorsal telencephalic glutamatergic neurons but not forebrain GABAergic neurons rescued the deficits in corticospinal motor neuron development of CB1-null mice and restored susceptibility to THC-induced motor alterations. In addition, THC administration induced an increase in seizure susceptibility that was mediated by its interference with CB1-dependent regulation of both glutamatergic and GABAergic neuron development. These findings demonstrate that prenatal exposure to THC has long-lasting deleterious consequences in the adult offspring solely mediated by its ability to disrupt the neurodevelopmental role of CB1 signaling.

  19. Development and characterization of immobilized cannabinoid receptor (CB1/CB2) open tubular column for on-line screening.

    Science.gov (United States)

    Moaddel, R; Rosenberg, A; Spelman, K; Frazier, J; Frazier, C; Nocerino, S; Brizzi, A; Mugnaini, C; Wainer, I W

    2011-05-01

    Cannabinoid receptors, CB1 and CB2, are therapeutic targets in the treatment of anxiety, obesity, movement disorders, glaucoma, and pain. We have developed an on-line screening method for CB1 and CB2 ligands, where cellular membrane fragments of a chronic myelogenous leukemia cell line, KU-812, were immobilized onto the surface of an open tubular (OT) capillary to create a CB1/CB2-OT column. The binding activities of the immobilized CB1/CB2 receptors were established using frontal affinity chromatographic techniques. This is the first report that confirms the presence of functional CB1 and CB2 receptors on KU-812 cells. The data from this study confirm that the CB1/CB2-OT column can be used to determine the binding affinities (K(i) values) for a single compound and to screen individual compounds or a mixture of multiple compounds. The CB1/CB2-OT column was also used to screen a botanical matrix, Zanthoxylum clava-herculis, where preliminary results suggest the presence of a high-affinity phytocannabinoid.

  20. Prejunctional and peripheral effects of the cannabinoid CB(1) receptor inverse agonist rimonabant (SR 141716).

    Science.gov (United States)

    van Diepen, Hester; Schlicker, Eberhard; Michel, Martin C

    2008-10-01

    Rimonabant is an inverse agonist specific for cannabinoid receptors and selective for their cannabinoid-1 (CB(1)) subtype. Although CB(1) receptors are more abundant in the central nervous system, rimonabant has many effects in the periphery, most of which are related to prejunctional modulation of transmitter release from autonomic nerves. However, CB(1) receptors are also expressed in, e.g., adipocytes and endothelial cells. Rimonabant inhibits numerous cardiovascular cannabinoid effects, including the decrease of blood pressure by central and peripheral (cardiac and vascular) sites of action, with the latter often being endothelium dependent. Rimonabant may also antagonize cannabinoid effects in myocardial infarction and in hypotension associated with septic shock or liver cirrhosis. In the gastrointestinal tract, rimonabant counteracts the cannabinoid-induced inhibition of secretion and motility. Although not affecting most cannabinoid effects in the airways, rimonabant counteracts inhibition of smooth-muscle contraction by cannabinoids in urogenital tissues and may interfere with embryo attachment and outgrowth of blastocysts. It inhibits cannabinoid-induced decreases of intraocular pressure. Rimonabant can inhibit proliferation of, maturation of, and energy storage by adipocytes. Among the many cannabinoid effects on hormone secretion, only some are rimonabant sensitive. The effects of rimonabant on the immune system are not fully clear, and it may inhibit or stimulate proliferation in several types of cancer. We conclude that direct effects of rimonabant on adipocytes may contribute to its clinical role in treating obesity. Other peripheral effects, many of which occur prejunctionally, may also contribute to its overall clinical profile and lead to additional indications as well adverse events.

  1. Neurophysiological evidence for the presence of cannabinoid CB1 receptors in the laterodorsal tegmental nucleus

    DEFF Research Database (Denmark)

    Soni, Neeraj; Satpathy, Shankha; Kohlmeier, Kristi Anne

    2014-01-01

    Marijuana, which acts within the endocannabinoid (eCB) system as an agonist of the cannabinoid type 1 receptor (CB1R), exhibits addictive properties and has powerful actions on the state of arousal of an organism. The laterodorsal tegmental nucleus (LDT), as a component of the reticular activating...... the firing frequency and synaptic activity of neurons in this nucleus. Therefore, endogenous eCB transmission could play a role in processes involving the LDT, such as cortical activation and motivated behaviours and, further, behavioural actions of marijuana are probably mediated, in part, via cellular...

  2. Acute and chronic systemic CB1 cannabinoid receptor blockade improves blood pressure regulation and metabolic profile in hypertensive (mRen2)27 rats.

    Science.gov (United States)

    Schaich, Chris L; Shaltout, Hossam A; Brosnihan, K Bridget; Howlett, Allyn C; Diz, Debra I

    2014-08-01

    We investigated acute and chronic effects of CB1 cannabinoid receptor blockade in renin-angiotensin system-dependent hypertension using rimonabant (SR141716A), an orally active antagonist with central and peripheral actions. In transgenic (mRen2)27 rats, a model of angiotensin II-dependent hypertension with increased body mass and insulin resistance, acute systemic blockade of CB1 receptors significantly reduced blood pressure within 90 min but had no effect in Sprague-Dawley rats. No changes in metabolic hormones occurred with the acute treatment. During chronic CB1 receptor blockade, (mRen2)27 rats received daily oral administration of SR141716A (10 mg/kg/day) for 28 days. Systolic blood pressure was significantly reduced within 24 h, and at Day 21 of treatment values were 173 mmHg in vehicle versus 149 mmHg in drug-treated rats (P < 0.01). This accompanied lower cumulative weight gain (22 vs. 42 g vehicle; P < 0.001), fat mass (2.0 vs. 2.9% of body weight; P < 0.05), and serum leptin (2.8 vs. 6.0 ng/mL; P < 0.05) and insulin (1.0 vs. 1.9 ng/mL; P < 0.01), following an initial transient decrease in food consumption. Conscious hemodynamic recordings indicate twofold increases occurred in spontaneous baroreflex sensitivity (P < 0.05) and heart rate variability (P < 0.01), measures of cardiac vagal tone. The beneficial actions of CB1 receptor blockade in (mRen2)27 rats support the interpretation that an upregulated endocannabinoid system contributes to hypertension and impaired autonomic function in this angiotensin II-dependent model. We conclude that systemic CB1 receptor blockade may be an effective therapy for angiotensin II-dependent hypertension and associated metabolic syndrome.

  3. CB1 and CB2 receptor agonists promote analgesia through synergy in a murine model of tumor pain.

    Science.gov (United States)

    Khasabova, Iryna A; Gielissen, James; Chandiramani, Anisha; Harding-Rose, Catherine; Odeh, Desiree Abu; Simone, Donald A; Seybold, Virginia S

    2011-09-01

    In light of the adverse side-effects of opioids, cannabinoid receptor agonists may provide an effective alternative for the treatment of cancer pain. This study examined the potency and efficacy of synthetic CB1 and CB2 receptor agonists in a murine model of tumor pain. Intraplantar injection of the CB1 receptor agonist arachidonylcyclopropylamide (ED(50) of 18.4 μg) reduced tumor-related mechanical hyperalgesia by activation of peripheral CB1 but not CB2 receptors. Similar injection of the CB2 receptor agonist AM1241 (ED50 of 19.5 μg) reduced mechanical hyperalgesia by activation of peripheral CB2 but not CB1 receptors. Both agonists had an efficacy comparable with that of morphine (intraplantar), but their analgesic effects were independent of opioid receptors. Isobolographic analysis of the coinjection of arachidonylcyclopropylamide and AM1241 determined that the CB1 and CB2 receptor agonists interacted synergistically to reduce mechanical hyperalgesia in the tumor-bearing paw. These data extend our previous findings that the peripheral cannabinoid receptors are a promising target for the management of cancer pain and mixed cannabinoid receptor agonists may have a therapeutic advantage over selective agonists.

  4. Endocannabinoids in the brainstem modulate dural trigeminovascular nociceptive traffic via CB1 and "triptan" receptors: implications in migraine.

    Science.gov (United States)

    Akerman, Simon; Holland, Philip R; Lasalandra, Michele P; Goadsby, Peter J

    2013-09-11

    Activation and sensitization of trigeminovascular nociceptive pathways is believed to contribute to the neural substrate of the severe and throbbing nature of pain in migraine. Endocannabinoids, as well as being physiologically analgesic, are known to inhibit dural trigeminovascular nociceptive responses. They are also involved in the descending modulation of cutaneous-evoked C-fiber spinal nociceptive responses from the brainstem. The purpose of this study was to determine whether endocannabinoids are involved in the descending modulation of dural and/or cutaneous facial trigeminovascular nociceptive responses, from the brainstem ventrolateral periaqueductal gray (vlPAG). CB1 receptor activation in the vlPAG attenuated dural-evoked Aδ-fiber neurons (maximally by 19%) and basal spontaneous activity (maximally by 33%) in the rat trigeminocervical complex, but there was no effect on cutaneous facial receptive field responses. This inhibitory vlPAG-mediated modulation was inhibited by specific CB1 receptor antagonism, given via the vlPAG, and with a 5-HT1B/1D receptor antagonist, given either locally in the vlPAG or systemically. These findings demonstrate for the first time that brainstem endocannabinoids provide descending modulation of both basal trigeminovascular neuronal tone and Aδ-fiber dural-nociceptive responses, which differs from the way the brainstem modulates spinal nociceptive transmission. Furthermore, our data demonstrate a novel interaction between serotonergic and endocannabinoid systems in the processing of somatosensory nociceptive information, suggesting that some of the therapeutic action of triptans may be via endocannabinoid containing neurons in the vlPAG.

  5. Enhanced in vivo absorption of CB-1 antagonist in rats via solid solutions prepared by hot-melt extrusion.

    Science.gov (United States)

    Ranzani, L S; Font, J; Galimany, F; Santanach, A; Gomez-Gomar, A M; Casadevall, G; Gryczke, A

    2011-06-01

    The aim of the present work was to investigate in vitro dissolution properties of three binary solid solutions prepared by a hot-melt extrusion (HME) process with vinyl pirrolidone--vinyl acetate copolymer (Kollidon VA 64), ethyl acrylate, methyl methacrylate polymer (Eudragit E) polyetilenglicol 8000 (PEG 8000) with a cannabinoid type 1 (CB-1) antagonist. Hansen solubility parameters were calculated from the chemical structures of the drug and the individual polymers in order to predict miscibility. Solid state characterizations of drug substance, physical blends and HME formulations were performed with differential scanning calorimetry. The dissolution testing conducted under sink conditions revealed that the dissolution rate of HME formulations improved around 1.8-fold vs drug substance. Supersaturation dissolution study demonstrated that HME formulations composed by Eudragit E and Kollidon VA64 increased drug solubility between 30- and 35-fold, respectively comparing to the drug substance. Physical and chemical stability of formulations were studied at 40°C/75%HR with open dish during 15 days. The formulation composed by the drug and Eudragit E at 10:90 was evaluated for in vivo drug absorption in male Wistar-Hannover rats and it was found to increase CB-1 absorption threefold greater than pure drug oral suspension.

  6. MicroRNA let-7d is a target of cannabinoid CB1 receptor and controls cannabinoid signaling.

    Science.gov (United States)

    Chiarlone, Anna; Börner, Christine; Martín-Gómez, Laura; Jiménez-González, Ada; García-Concejo, Adrián; García-Bermejo, María L; Lorente, Mar; Blázquez, Cristina; García-Taboada, Elena; de Haro, Amador; Martella, Elisa; Höllt, Volker; Rodríguez, Raquel; Galve-Roperh, Ismael; Kraus, Jürgen; Guzmán, Manuel

    2016-09-01

    Cannabinoid CB1 receptor, the molecular target of endocannabinoids and cannabis active components, is one of the most abundant metabotropic receptors in the brain. Cannabis is widely used for both recreational and medicinal purposes. Despite the ever-growing fundamental roles of microRNAs in the brain, the possible molecular connections between the CB1 receptor and microRNAs are surprisingly unknown. Here, by using reporter gene constructs that express interaction sequences for microRNAs in human SH-SY5Y neuroblastoma cells, we show that CB1 receptor activation enhances the expression of several microRNAs, including let-7d. This was confirmed by measuring hsa-let-7d expression levels. Accordingly, knocking-down CB1 receptor in zebrafish reduced dre-let-7d levels, and knocking-out CB1 receptor in mice decreased mmu-let-7d levels in the cortex, striatum and hippocampus. Conversely, knocking-down let-7d increased CB1 receptor mRNA expression in zebrafish, SH-SY5Y cells and primary striatal neurons. Likewise, in primary striatal neurons chronically exposed to a cannabinoid or opioid agonist, a let-7d-inhibiting sequence facilitated not only cannabinoid or opioid signaling but also cannabinoid/opioid cross-signaling. Taken together, these findings provide the first evidence for a bidirectional link between the CB1 receptor and a microRNA, namely let-7d, and thus unveil a new player in the complex process of cannabinoid action.

  7. Recent development of CB2 selective and peripheral CB1/CB2 cannabinoid receptor ligands.

    Science.gov (United States)

    Nevalainen, Tapio

    2014-01-01

    Cannabinoids have potential therapeutic value e.g. in pain relief, cancer therapy, control of nausea and vomiting, and appetite stimulation, but their therapeutic benefits are limited by unwanted central nervous system (CNS) side-effects. Separating the therapeutic effects of cannabinoid agonists from their undesired CNS effects can be achieved by either increasing the selectivity of the ligands for the CB2 receptor or by developing peripherally restricted CB1/CB2 ligands. A vast number of structurally diverse CB2 ligands have been developed during the past 3 years, stemming from the screening hits, which are further optimized towards lead compounds and drug candidates. Some of CB2 ligands may ultimately enter into clinical use as pain relief, anticancer, or antipruritic agents. This review focuses on the recent literature dealing with selective CB2 receptor ligands, with a particular emphasis on the CB2 agonists developed from 2009 onwards.

  8. Epidermal Growth Factor Receptor Transactivation by the Cannabinoid Receptor (CB1) and Transient Receptor Potential Vanilloid 1 (TRPV1) Induces Differential Responses in Corneal Epithelial Cells

    Science.gov (United States)

    2010-01-01

    inhibitors of proteolytic release of heparin bound EGF ( HB -EGF). CB1- induced Ca2þ transients were reduced during exposure to either the CB1 antagonist...blockage eliminated this response. Furthermore, EGFR transactivation was abolished by inhibitors of proteolytic release of heparin bound EGF ( HB -EGF...IL-8 or IL-6 Chemiluminescent Immunoassay ; R&D Systems, Minneapolis, MN). The cells were washed with basic medium and then exposed to CPZ, or AM251

  9. Regulation of transient receptor potential channels of melastatin type 8 (TRPM8): effect of cAMP, cannabinoid CB(1) receptors and endovanilloids.

    Science.gov (United States)

    De Petrocellis, Luciano; Starowicz, Katarzyna; Moriello, Aniello Schiano; Vivese, Marta; Orlando, Pierangelo; Di Marzo, Vincenzo

    2007-05-15

    The transient receptor potential channel of melastatin type 8 (TRPM8), which is gated by low (<25 degrees C) temperature and chemical compounds, is regulated by protein kinase C-mediated phosphorylation in a way opposite to that observed with the transient receptor potential channel of vanilloid type 1 (TRPV1), i.e. by being desensitized and not sensitized. As TRPV1 is sensitized also by protein kinase A (PKA)-mediated phosphorylation, we investigated the effect of two activators of the PKA pathway, 8-Br-cAMP and forskolin, on the activity of menthol and icilin at TRPM8 in HEK-293 cells stably overexpressing the channel (TRPM8-HEK-293 cells). We also studied the effect on TRPM8 of: (1) a series of compounds previously shown to activate or antagonize TRPV1, and (2) co-stimulation of transiently co-expressed cannabinoid CB(1) receptors. Both 8-Br-cAMP (100 microM) and forskolin (10 microM) right-shifted the dose-response curves for the TRPM8-mediated effect of icilin and menthol on intracellular Ca(2+). The inhibitory effects of 8-Br-cAMP and forskolin were attenuated by the selective PKA inhibitor Rp-cAMP-S. Stimulation of human CB(1) receptors transiently co-expressed in TRPM8-HEK-293 cells also inhibited TRPM8 response to icilin. Finally, some TRPV1 agonists and antagonists, but not iodinated antagonists, antagonized icilin- and much less so menthol-, induced TRPM8 activation. Importantly, the endovanilloids/endocannabinoids, anandamide and NADA, also antagonized TRPM8 at submicromolar concentrations. Although these findings need to be confirmed by experiments directly measuring TRPM8 activity in natively TRPM8-expressing cells, they support the notion that the same regulatory events have opposing actions on TRPM8 and TRPV1 receptors and identify anandamide and NADA as the first potential endogenous functional antagonists of TRPM8 channels.

  10. The expression level of CB1 and CB2 receptors determines their efficacy at inducing apoptosis in astrocytomas.

    Directory of Open Access Journals (Sweden)

    Eiron Cudaback

    Full Text Available BACKGROUND: Cannabinoids represent unique compounds for treating tumors, including astrocytomas. Whether CB(1 and CB(2 receptors mediate this therapeutic effect is unclear. PRINCIPAL FINDINGS: We generated astrocytoma subclones that express set levels of CB(1 and CB(2, and found that cannabinoids induce apoptosis only in cells expressing low levels of receptors that couple to ERK1/2. In contrast, cannabinoids do not induce apoptosis in cells expressing high levels of receptors because these now also couple to the prosurvival signal AKT. Remarkably, cannabinoids applied at high concentration induce apoptosis in all subclones independently of CB(1, CB(2 and AKT, but still through a mechanism involving ERK1/2. SIGNIFICANCE: The high expression level of CB(1 and CB(2 receptors commonly found in malignant astrocytomas precludes the use of cannabinoids as therapeutics, unless AKT is concomitantly inhibited, or cannabinoids are applied at concentrations that bypass CB(1 and CB(2 receptors, yet still activate ERK1/2.

  11. Anticonvulsant effects of N-arachidonoyl-serotonin, a dual fatty acid amide hydrolase enzyme and transient receptor potential vanilloid type-1 (TRPV1) channel blocker, on experimental seizures: the roles of cannabinoid CB1 receptors and TRPV1 channels.

    Science.gov (United States)

    Vilela, Luciano R; Medeiros, Daniel C; de Oliveira, Antonio Carlos P; Moraes, Marcio F; Moreira, Fabricio A

    2014-10-01

    Selective blockade of anandamide hydrolysis, through the inhibition of the FAAH enzyme, has anticonvulsant effects, which are mediated by CB1 receptors. Anandamide, however, also activates TRPV1 channels, generally with an opposite outcome on neuronal modulation. Thus, we suggested that the dual FAAH and TRPV1 blockade with N-arachidonoyl-serotonin (AA-5-HT) would be efficacious in inhibiting pentylenetetrazole (PTZ)-induced seizures in mice. We also investigated the contribution of CB1 activation and TRPV1 blockade to the overt effect of AA-5-HT. In the first experiment, injection of AA-5-HT (0.3-3.0 mg/kg) delayed the onset and reduced the duration of PTZ (60 mg)-induced seizures in mice. These effects were reversed by pre-treatment with the CB1 antagonist, AM251 (1.0-3.0 mg/kg). Finally, we observed that administration of the selective TRPV1 antagonist, SB366791 (0.1-1 mg/kg), did not entirely mimic AA-5-HT effects. In conclusion, AA-5-HT alleviates seizures in mice, an effect inhibited by CB1 antagonism, but not completely mimicked by TRPV1 blockage, indicating that the overall effect of AA-5-HT seems to depend mainly on CB1 receptors. This may represent a new strategy for the development of drugs against seizures, epilepsies and related syndromes.

  12. WAG/Rij rats show a reduced expression of CB1 receptors in thalamic nuclei and respond to the CB1 receptor agonist, R(+)WIN55,212-2, with a reduced incidence of spike-wave discharges

    NARCIS (Netherlands)

    Rijn, C.M. van; Gaetani, S.; Santolini, I.; Badura, A.; Fu, J.; Watanabe, M.; Cuomo, V.; Luijtelaar, E.L.J.M. van; Nicoletti, F.; Ngomba, R.T.

    2010-01-01

    Purpose: Genetically epileptic WAG/Rij rats develop spontaneous absence-like seizures after 3 months of age. We used WAG/Rij rats to examine whether absence seizures are associated with changes in the expression of type-1 cannabinoid (CB1) receptors. Methods: Receptor expression was examined by in s

  13. Diarylureas as allosteric modulators of the cannabinoid CB1 receptor: structure-activity relationship studies on 1-(4-chlorophenyl)-3-{3-[6-(pyrrolidin-1-yl)pyridin-2-yl]phenyl}urea (PSNCBAM-1).

    Science.gov (United States)

    German, Nadezhda; Decker, Ann M; Gilmour, Brian P; Gay, Elaine A; Wiley, Jenny L; Thomas, Brian F; Zhang, Yanan

    2014-09-25

    The recent discovery of allosteric modulators of the CB1 receptor including PSNCBAM-1 (4) has generated significant interest in CB1 receptor allosteric modulation. Here in the first SAR study on 4, we have designed and synthesized a series of analogs focusing on modifications at two positions. Pharmacological evaluation in calcium mobilization and binding assays revealed the importance of alkyl substitution at the 2-aminopyridine moiety and electron deficient aromatic groups at the 4-chlorophenyl position for activity at the CB1 receptor, resulting in several analogs with comparable potency to 4. These compounds increased the specific binding of [(3)H]CP55,940, in agreement with previous reports. Importantly, 4 and two analogs dose-dependently reduced the Emax of the agonist curve in the CB1 calcium mobilization assays, confirming their negative allosteric modulator characteristics. Given the side effects associated with CB1 receptor orthosteric antagonists, negative allosteric modulators provide an alternative approach to modulate the pharmacologically important CB1 receptor.

  14. Involvement of a non-CB1/CB2 cannabinoid receptor in the aqueous humor outflow-enhancing effects of abnormal-cannabidiol.

    Science.gov (United States)

    Qiao, Zhuanhong; Kumar, Akhilesh; Kumar, Pritesh; Song, Zhao-Hui

    2012-07-01

    The purpose of this study was to investigate the effects of abnormal-cannabidiol (abn-cbd), a non-psychoactive cannabinoid agonist, on aqueous humor outflow via the trabecular meshwork (TM) of porcine eye, and to examine the involvement of a non-CB1/CB2 cannabinoid receptor and the p42/44 mitogen-activated protein kinase (p42/44 MAPK) pathway. The effects of abn-cbd on aqueous humor outflow were measured using a porcine anterior segment perfused organ culture model. The activation of p42/44 MAPK by abn-cbd was determined in cultured TM cells with western blot analysis using an anti-phospho-p42/44 MAPK antibody. Administration of abn-cbd caused a concentration-dependent enhancement of aqueous humor outflow facility with a maximum effect (155.0 ± 11.7% of basal outflow facility) after administration of 30 nM abn-cbd. Pretreatment with 1 μM of O-1918, a cannabidiol analog that acts as a selective antagonist at the non-CB1/CB2 receptor, produced a full antagonism of 30 nM abn-cbd induced increase of aqueous humor outflow facility. Pretreatment with 1 μM of CB1 antagonist SR141716A partially blocked, whereas pretreatment with either 1 μM of CB1 antagonist AM251 or 1 μM of CB2 antagonist SR144528 had no effect on abn-cbd induced enhancement of outflow facility. Treatment of TM cells with 30 nM of abn-cbd activated p42/44 MAPK, which was blocked completely by pretreatment with O-1918, and partially by pretreatment with SR141716A, but not by either AM251 or SR144528. In addition, PD98059, an inhibitor of p42/44 MAPK pathway, blocked completely the abn-cbd induced p42/44 MAPK activation and blocked partially the abn-cbd induced enhancement of outflow facility. In conclusion, the results from this study demonstrate that abn-cbd increases aqueous humor outflow through the TM pathway of the eye, and this effect is mediated by a non-CB1/CB2 cannabinoid receptor, with an involvement of p42/44 MAPK signaling pathway.

  15. Involvement of a non-CB1/CB2 cannabinoid receptor in the aqueous humor outflow-enhancing effects of abnormal-cannabidiol

    Science.gov (United States)

    Qiao, Zhuanhong; Kumar, Akhilesh; Kumar, Pritesh; Song, Zhao-Hui

    2016-01-01

    The purpose of this study was to investigate the effects of abnormal-cannabidiol (abn-cbd), a non-psychoactive cannabinoid agonist, on aqueous humor outflow via the trabecular meshwork (TM) of porcine eye, and to examine the involvement of a non-CB1/CB2 cannabinoid receptor and the p42/44 mitogen-activated protein kinase (p42/44 MAPK) pathway. The effects of abn-cbd on aqueous humor outflow were measured using a porcine anterior segment perfused organ culture model. The activation of p42/44 MAPK by abn-cbd was determined in cultured TM cells with western blot analysis using an anti-phospho-p42/44 MAPK antibody. Administration of abn-cbd caused a concentration-dependent enhancement of aqueous humor outflow facility with a maximum effect (155.0 ± 11.7% of basal outflow facility) after administration of 30 nM abn-cbd. Pretreatment with 1 μM of O-1918, a cannabidiol analog that acts as a selective antagonist at the non-CB1/CB2 receptor, produced a full antagonism of 30 nM abn-cbd induced increase of aqueous humor outflow facility. Pretreatment with 1 μM of CB1 antagonist SR141716A partially blocked, whereas pretreatment with either 1 μM of CB1 antagonist AM251 or 1 μM of CB2 antagonist SR144528 had no effect on abn-cbd induced enhancement of outflow facility. Treatment of TM cells with 30 nM of abn-cbd activated p42/44 MAPK, which was blocked completely by pretreatment with O-1918, and partially by pretreatment with SR141716A, but not by either AM251 or SR144528. In addition, PD98059, an inhibitor of p42/44 MAPK pathway, blocked completely the abn-cbd induced p42/44 MAPK activation and blocked partially the abn-cbd induced enhancement of outflow facility. In conclusion, the results from this study demonstrate that abn-cbd increases aqueous humor outflow through the TM pathway of the eye, and this effect is mediated by a non-CB1/CB2 cannabinoid receptor, with an involvement of p42/44 MAPK signaling pathway. PMID:22580290

  16. Role of CB1 and CB2 cannabinoid receptors in the development of joint pain induced by monosodium iodoacetate.

    Science.gov (United States)

    La Porta, Carmen; Bura, Simona Andreea; Aracil-Fernández, Auxiliadora; Manzanares, Jorge; Maldonado, Rafael

    2013-01-01

    Joint pain is a common clinical problem for which both inflammatory and degenerative joint diseases are major causes. The purpose of this study was to investigate the role of CB1 and CB2 cannabinoid receptors in the behavioral, histological, and neurochemical alterations associated with joint pain. The murine model of monosodium iodoacetate (MIA) was used to induce joint pain in knockout mice for CB1 (CB1KO) and CB2 cannabinoid receptors (CB2KO) and transgenic mice overexpressing CB2 receptors (CB2xP). In addition, we evaluated the changes induced by MIA in gene expression of CB1 and CB2 cannabinoid receptors and μ-, δ- and κ-opioid receptors in the lumbar spinal cord of these mice. Wild-type mice, as well as CB1KO, CB2KO, and CB2xP mice, developed mechanical allodynia in the ipsilateral paw after MIA intra-articular injection. CB1KO and CB2KO demonstrated similar levels of mechanical allodynia of that observed in wild-type mice in the ipsilateral paw, whereas allodynia was significantly attenuated in CB2xP. Interestingly, CB2KO displayed a contralateral mirror image of pain developing mechanical allodynia also in the contralateral paw. All mouse lines developed similar histological changes after MIA intra-articular injection. Nevertheless, MIA intra-articular injection produced specific changes in the expression of cannabinoid and opioid receptor genes in lumbar spinal cord sections that were further modulated by the genetic alteration of the cannabinoid receptor system. These results revealed that CB2 receptor plays a predominant role in the control of joint pain manifestations and is involved in the adaptive changes induced in the opioid system under this pain state.

  17. Presynaptic cannabinoid CB(1) receptors are involved in the inhibition of the neurogenic vasopressor response during septic shock in pithed rats.

    Science.gov (United States)

    Godlewski, Grzegorz; Malinowska, Barbara; Schlicker, Eberhard

    2004-06-01

    1. Our study was undertaken to investigate whether bacterial endotoxin/lipopolysaccharide (LPS) affects the neurogenic vasopressor response in rats in vivo by presynaptic mechanisms and, if so, to characterize the type of presynaptic receptor(s) operating in the initial phase of septic shock. 2. In pithed and vagotomized rats treated with pancuronium, electrical stimulation (ES) (1 Hz, 1 ms, 50 V for 10 s) of the preganglionic sympathetic nerve fibers or intravenous bolus injection of noradrenaline (NA) (1-3 nmol x kg(-1)) increased the diastolic blood pressure (DBP) by about 30 mmHg. Administration of LPS (0.4 and 4 mg x kg(-1)) under continuous infusion of vasopressin inhibited the neurogenic vasopressor response by 25 and 50%, respectively. LPS did not affect the increase in DBP induced by exogenous NA. 3. The LPS-induced inhibition of the neurogenic vasopressor response was counteracted by the cannabinoid CB(1) receptor antagonist SR 141716A (0.1 micromol x kg(-1)), but not by the CB(2) receptor antagonist SR 144528 (3 micromol x kg(-1)), the vanilloid VR1 receptor antagonist capsazepine (1 micromol x kg(-1)) or the histamine H(3) receptor antagonist clobenpropit (0.1 micromol x kg(-1)). The four antagonists by themselves did not affect the increase in DBP induced by ES or by injection of NA in rats not exposed to LPS. 4. We conclude that in the initial phase of septic shock, the activation of presynaptic CB(1) receptors by endogenously formed cannabinoids contributes to the inhibition of the neurogenic vasopressor response.

  18. Localization and function of the cannabinoid CB1 receptor in the anterolateral bed nucleus of the stria terminalis.

    Directory of Open Access Journals (Sweden)

    Nagore Puente

    Full Text Available BACKGROUND: The bed nucleus of the stria terminalis (BNST is involved in behaviors related to natural reward, drug addiction and stress. In spite of the emerging role of the endogenous cannabinoid (eCB system in these behaviors, little is known about the anatomy and function of this system in the anterolateral BNST (alBNST. The aim of this study was to provide a detailed morphological characterization of the localization of the cannabinoid 1 (CB1 receptor a necessary step toward a better understanding of the physiological roles of the eCB system in this region of the brain. METHODOLOGY/PRINCIPAL FINDINGS: We have combined anatomical approaches at the confocal and electron microscopy level to ex-vivo electrophysiological techniques. Here, we report that CB1 is localized on presynaptic membranes of about 55% of immunopositive synaptic terminals for the vesicular glutamate transporter 1 (vGluT1, which contain abundant spherical, clear synaptic vesicles and make asymmetrical synapses with alBNST neurons. About 64% of vGluT1 immunonegative synaptic terminals show CB1 immunolabeling. Furthermore, 30% and 35% of presynaptic boutons localize CB1 in alBNST of conditional mutant mice lacking CB1 mainly from GABAergic neurons (GABA-CB1-KO mice and mainly from cortical glutamatergic neurons (Glu-CB1-KO mice, respectively. Extracellular field recordings and whole cell patch clamp in the alBNST rat brain slice preparation revealed that activation of CB1 strongly inhibits excitatory and inhibitory synaptic transmission. CONCLUSIONS/SIGNIFICANCE: This study supports the anterolateral BNST as a potential neuronal substrate of the effects of cannabinoids on stress-related behaviors.

  19. The Effects of Targeted Deletion of Cannabinoid Receptors CB1 and CB2 on Intranasal Sensitization and Challenge with Adjuvant-Free Ovalbumin

    OpenAIRE

    Kaplan, Barbara L. F.; Oberdick, Jody E.; Karmaus, Peer W. F.; Ngaotepprutaram, Thitirat; Birmingham, Neil P.; Harkema, Jack R.; Kaminski, Norbert E.

    2010-01-01

    The mechanisms by which cannabinoid receptors CB1 and CB2 modulate immune function are not fully elucidated. Critical tools for the determination of the role of both receptors in the immune system are CB1/CB2 double null mice (CB1/CB2 null), and previous studies have shown that CB1/CB2 null mice exhibit exaggerated responses to various immunological stimuli. The objective of these studies was to determine the magnitude to which CB1/CB2 null mice responded to the respiratory allergen ovalbumin...

  20. Functional interaction between the orexin-1 and CB1 receptors within the nucleus accumbens in the conditioned place preference induced by the lateral hypothalamus stimulation.

    Science.gov (United States)

    Fatahi, Zahra; Assar, Nasim; Mahmoudi, Dorna; Pahlevani, Pouyan; Moradi, Marzieh; Haghparast, Abbas

    2015-02-28

    Several studies have shown that chemical stimulation of the lateral hypothalamus (LH) by carbachol induces the conditioned place preference (CPP) in rats. LH is the main source of the orexinergic neurons and sends projections to some areas of the brain such as the nucleus accumbens (NAc). We tried to determine the role of intra-accumbal orexin-1 (OX1) receptors in development (acquisition) and expression of reward-related behaviors induced by LH stimulation and involvement of CB1 cannabinoid receptors in this area. Adult male Wistar rats were unilaterally implanted by two separate cannulae into the LH and NAc. The CPP paradigm was done; conditioning scores and locomotor activities were recorded. The results showed that intra-accumbal administration of SB334867 as a selective OX1 receptor antagonist (1, 3, 10 and 30nM/0.5μl DMSO) 5min before intra-LH carbachol (250nM/0.5μl saline) during 3-day conditioning phase, could dose-dependently inhibit the development of LH-induced CPP. In expression experiments, intra-NAc administration of SB334867 on the test day could decrease the expression of LH stimulation-induced CPP. Furthermore, concurrent intra-accumbal administration of effective/ineffective doses of SB334867 and AM251 (45 and 15μM) as a CB1 receptor antagonist, before carbachol during the conditioning phase, could attenuate the development of LH stimulation-induced CPP. It seems that the orexinergic projection from the LH to the NAc is involved in the LH stimulation-induced CPP and OX1 receptor in the NAc has a substantial role in this phenomenon. Our findings also suggest the existence a functional interaction between OX1 and CB1 receptors within the NAc in place preference.

  1. Cannabinoid CB1 receptor inhibition blunts adolescent-typical increased binge alcohol and sucrose consumption in male C57BL/6J mice.

    Science.gov (United States)

    Agoglia, Abigail E; Holstein, Sarah E; Eastman, Vallari R; Hodge, Clyde W

    2016-04-01

    Increased binge alcohol consumption has been reported among adolescents as compared to adults in both humans and rodent models, and has been associated with serious long-term health consequences. However, the neurochemical mechanism for age differences in binge drinking between adolescents and adults has not been established. The present study was designed to evaluate the mechanistic role of the cannabinoid CB1 receptor in adolescent and adult binge drinking. Binge consumption was established in adolescent and adult male C57BL/6J mice by providing access to 20% alcohol or 1% sucrose for 4h every other day. Pretreatment with the CB1 antagonist/inverse agonist AM-251 (0, 1, 3, and 10mg/kg) in a Latin square design dose-dependently reduced adolescent alcohol consumption to adult levels without altering adult intake. AM-251 (3mg/kg) also reduced adolescent but not adult sucrose consumption. Adolescent reductions in alcohol and sucrose were not associated with alterations in open-field locomotor activity or thigmotaxis. These findings point to age differences in CB1 receptor activity as a functional mediator of adolescent-typical increased binge drinking as compared to adults. Developmental alterations in endocannabinoid signaling in the adolescent brain may therefore be responsible for the drinking phenotype seen in this age group.

  2. Cytotoxicity of synthetic cannabinoids on primary neuronal cells of the forebrain: the involvement of cannabinoid CB1 receptors and apoptotic cell death.

    Science.gov (United States)

    Tomiyama, Ken-ichi; Funada, Masahiko

    2014-01-01

    The abuse of herbal products containing synthetic cannabinoids has become an issue of public concern. The purpose of this paper was to evaluate the acute cytotoxicity of synthetic cannabinoids on mouse brain neuronal cells. Cytotoxicity induced by synthetic cannabinoid (CP-55,940, CP-47,497, CP-47,497-C8, HU-210, JWH-018, JWH-210, AM-2201, and MAM-2201) was examined using forebrain neuronal cultures. These synthetic cannabinoids induced cytotoxicity in the forebrain cultures in a concentration-dependent manner. The cytotoxicity was suppressed by preincubation with the selective CB1 receptor antagonist AM251, but not with the selective CB2 receptor antagonist AM630. Furthermore, annexin-V-positive cells were found among the treated forebrain cells. Synthetic cannabinoid treatment induced the activation of caspase-3, and preincubation with a caspase-3 inhibitor significantly suppressed the cytotoxicity. These synthetic cannabinoids induced apoptosis through a caspase-3-dependent mechanism in the forebrain cultures. Our results indicate that the cytotoxicity of synthetic cannabinoids towards primary neuronal cells is mediated by the CB1 receptor, but not by the CB2 receptor, and further suggest that caspase cascades may play an important role in the apoptosis induced by these synthetic cannabinoids. In conclusion, excessive synthetic cannabinoid abuse may present a serious acute health concern due to neuronal damage or deficits in the brain.

  3. Dietary ω-3 Polyunsaturated Fatty Acids Inhibit Tumor Growth in Transgenic Apc(Min/+) Mice, Correlating with CB1 Receptor Up-Regulation.

    Science.gov (United States)

    Notarnicola, Maria; Tutino, Valeria; De Nunzio, Valentina; Dituri, Francesco; Caruso, Maria Gabriella; Giannelli, Gianluigi

    2017-02-24

    Mediterranean diet components, such as olive oil and ω-3 polyunsaturated fatty acids (ω-3 PUFAs), can arrest cell growth and promote cell apoptosis. Recently, olive oil has been demonstrated to modulate type-1 cannabinoid (CB1) receptor gene expression in both human colon cancer cells and rat colon. The aim of this study was to investigate a possible link between olive oil and ω-3 PUFAs effects and CB1 receptor expression in both intestinal and adipose tissue of Apc(Min/+) mice. To confirm the role for the CB1 receptor as a negative modulator of cell proliferation in human colon cancer, CB1 receptor gene expression was also detected in tumor tissue and in surrounding normal mucosa of patients with colorectal cancer (CRC). Dietary ω-3 PUFAs significantly inhibited intestinal polyp growth in mice, correlating with CB1 receptor gene and protein expression induction. CB1 receptor gene up-regulation was also detected in adipose tissue, suggesting a close communication between cancer cells and the surrounding environment. Tissue CB1 receptor induction was associated with a concurrent inactivation of the Wnt/β-catenin pathway. Moreover, there was a significant reduction in CB1 receptor gene expression levels in cancer tissue compared to normal surrounding mucosa of patients with CRC, confirming that in cancer the "protective" action of the CB1 receptor is lost.

  4. In vitro and non-invasive in vivo effects of the cannabinoid-1 receptor (CB1R) agonist AM841 on gastrointestinal motor function in the rat

    Science.gov (United States)

    Abalo, R; Chen, C; Vera, G; Fichna, J; Thakur, GA; López-Pérez, AE; Makriyannis, A; Martín-Fontelles, MI; Storr, M

    2015-01-01

    Background Cannabinoids have been traditionally used for the treatment of gastrointestinal (GI) symptoms, but the associated central effects, through cannabinoid-1 receptors (CB1R), constitute an important drawback. Our aims were to characterize the effects of the recently developed highly potent long-acting megagonist AM841 on GI motor function and to determine its central effects in rats. Methods Male Wistar rats were used for in vitro and in vivo studies. The effect of AM841 was tested on electrically-induced twitch contractions of GI preparations (in vitro) and on GI motility measured radiographically after contrast administration (in vivo). Central effects of AM841 were evaluated using the cannabinoid tetrad. The non-selective cannabinoid agonist WIN 55,212-2 (WIN) was used for comparison. The CB1R (AM251) and CB2R (AM630) antagonists were used to characterize cannabinoid receptor-mediated effects of AM841. Key results AM841 dose-dependently reduced in vitro contractile activity of rat GI preparations via CB1R, but not CB2R or opioid receptors. In vivo, AM841 acutely and potently reduced gastric emptying and intestinal transit in a dose-dependent and AM251-sensitive manner. The in vivo GI effects of AM841 at 0.1 mg kg−1 were comparable to those induced by WIN at 5 mg kg−1. However, at this dose, AM841 did not induce any sign of the cannabinoid tetrad, whereas WIN induced significant central effects. Conclusions & Inferences The CB1R megagonist AM841 may potently depress GI motor function in the absence of central effects. This effect may be mediated peripherally and may be useful in the treatment of GI motility disorders. PMID:26387676

  5. Control of spasticity in a multiple sclerosis model using central nervous system-excluded CB1 cannabinoid receptor agonists.

    Science.gov (United States)

    Pryce, Gareth; Visintin, Cristina; Ramagopalan, Sreeram V; Al-Izki, Sarah; De Faveri, Lia E; Nuamah, Rosamond A; Mein, Charles A; Montpetit, Alexandre; Hardcastle, Alison J; Kooij, Gijs; de Vries, Helga E; Amor, Sandra; Thomas, Sarah A; Ledent, Catherine; Marsicano, Giovanni; Lutz, Beat; Thompson, Alan J; Selwood, David L; Giovannoni, Gavin; Baker, David

    2014-01-01

    The purpose of this study was the generation of central nervous system (CNS)-excluded cannabinoid receptor agonists to test the hypothesis that inhibition of spasticity, due to CNS autoimmunity, could be controlled by affecting neurotransmission within the periphery. Procedures included identification of chemicals and modeling to predict the mode of exclusion; induction and control of spasticity in the ABH mouse model of multiple sclerosis; conditional deletion of CB1 receptor in peripheral nerves; side-effect profiling to demonstrate the mechanism of CNS-exclusion via drug pumps; genome-wide association study in N2(129×ABH) backcross to map polymorphic cannabinoid drug pump; and sequencing and detection of cannabinoid drug-pump activity in human brain endothelial cell lines. Three drugs (CT3, SAB378 and SAD448) were identified that control spasticity via action on the peripheral nerve CB1 receptor. These were peripherally restricted via drug pumps that limit the CNS side effects (hypothermia) of cannabinoids to increase the therapeutic window. A cannabinoid drug pump is polymorphic and functionally lacking in many laboratory (C57BL/6, 129, CD-1) mice used for transgenesis, pharmacology, and toxicology studies. This phenotype was mapped and controlled by 1-3 genetic loci. ABCC1 within a cluster showing linkage is a cannabinoid CNS-drug pump. Global and conditional CB1 receptor-knockout mice were used as controls. In summary, CNS-excluded CB1 receptor agonists are a novel class of therapeutic agent for spasticity.

  6. Clinical Significance of Cannabinoid Receptors CB1 and CB2 Expression in Human Malignant and Benign Thyroid Lesions

    Directory of Open Access Journals (Sweden)

    Eleftheria Lakiotaki

    2015-01-01

    Full Text Available The endocannabinoid system is comprised of cannabinoid receptors (CB1 and CB2, their endogenous ligands (endocannabinoids, and proteins responsible for their metabolism participate in many different functions indispensable to homeostatic regulation in several tissues, exerting also antitumorigenic effects. The present study aimed to evaluate the clinical significance of CB1 and CB2 expression in human benign and malignant thyroid lesions. CB1 and CB2 proteins’ expression was assessed immunohistochemically on paraffin-embedded thyroid tissues obtained from 87 patients with benign (n=43 and malignant (n=44 lesions and was statistically analyzed with clinicopathological parameters, follicular cells’ proliferative capacity, and risk of recurrence rate estimated according to the American Thyroid Association (ATA staging system. Enhanced CB1 and CB2 expression was significantly more frequently observed in malignant compared to benign thyroid lesions (p=0.0010 and p=0.0005, resp.. Enhanced CB1 and CB2 expression was also significantly more frequently observed in papillary carcinomas compared to hyperplastic nodules (p=0.0097 and p=0.0110, resp.. In malignant thyroid lesions, elevated CB2 expression was significantly associated with the presence of lymph node metastases (p=0.0301. Enhanced CB2 expression was also more frequently observed in malignant thyroid cases with presence of capsular (p=0.1165, lymphatic (p=0.1989, and vascular invasion (p=0.0555, as well as in those with increased risk of recurrence rate (p=0.1165, at a nonsignificant level though, whereas CB1 expression was not associated with any of the clinicopathological parameters examined. Our data suggest that CB receptors may be involved in malignant thyroid transformation and especially CB2 receptor could serve as useful biomarker and potential therapeutic target in thyroid neoplasia.

  7. Clinical Significance of Cannabinoid Receptors CB1 and CB2 Expression in Human Malignant and Benign Thyroid Lesions.

    Science.gov (United States)

    Lakiotaki, Eleftheria; Giaginis, Constantinos; Tolia, Maria; Alexandrou, Paraskevi; Delladetsima, Ioanna; Giannopoulou, Ioanna; Kyrgias, George; Patsouris, Efstratios; Theocharis, Stamatios

    2015-01-01

    The endocannabinoid system is comprised of cannabinoid receptors (CB1 and CB2), their endogenous ligands (endocannabinoids), and proteins responsible for their metabolism participate in many different functions indispensable to homeostatic regulation in several tissues, exerting also antitumorigenic effects. The present study aimed to evaluate the clinical significance of CB1 and CB2 expression in human benign and malignant thyroid lesions. CB1 and CB2 proteins' expression was assessed immunohistochemically on paraffin-embedded thyroid tissues obtained from 87 patients with benign (n = 43) and malignant (n = 44) lesions and was statistically analyzed with clinicopathological parameters, follicular cells' proliferative capacity, and risk of recurrence rate estimated according to the American Thyroid Association (ATA) staging system. Enhanced CB1 and CB2 expression was significantly more frequently observed in malignant compared to benign thyroid lesions (p = 0.0010 and p = 0.0005, resp.). Enhanced CB1 and CB2 expression was also significantly more frequently observed in papillary carcinomas compared to hyperplastic nodules (p = 0.0097 and p = 0.0110, resp.). In malignant thyroid lesions, elevated CB2 expression was significantly associated with the presence of lymph node metastases (p = 0.0301). Enhanced CB2 expression was also more frequently observed in malignant thyroid cases with presence of capsular (p = 0.1165), lymphatic (p = 0.1989), and vascular invasion (p = 0.0555), as well as in those with increased risk of recurrence rate (p = 0.1165), at a nonsignificant level though, whereas CB1 expression was not associated with any of the clinicopathological parameters examined. Our data suggest that CB receptors may be involved in malignant thyroid transformation and especially CB2 receptor could serve as useful biomarker and potential therapeutic target in thyroid neoplasia.

  8. Coadministration of indomethacin and minocycline attenuates established paclitaxel-induced neuropathic thermal hyperalgesia: Involvement of cannabinoid CB1 receptors.

    Science.gov (United States)

    Parvathy, Subramanian S; Masocha, Willias

    2015-06-18

    Taxanes such as paclitaxel, which are chemotherapeutic drugs, cause dose-dependent painful neuropathy in some patients. We investigated whether coadministration of minocycline and indomethacin produces antinociceptive effects in mice with paclitaxel-induced neuropathic thermal hyperalgesia and if the cannabinoid system is involved. Previously, we reported that coadministration of these two drugs results in antinociception against inflammatory pain at doses where either drug alone lack significant activity. In the current study, we observed that treatment of female mice with indomethacin or minocycline alone did not affect established paclitaxel-induced thermal hyperalgesia, whereas coadministration of the two drugs attenuated it. In male mice indomethacin had some antihyperalgesic activity, whilst minocycline did not. Coadministration of the two drugs had supraadditive antihyperalgesic activity in male mice. Administration of a cannabinoid CB1 receptor antagonist AM 251 blocked the antihyperalgesic effects of the combination of minocycline and indomethacin in both male and female mice. In conclusion our results indicate that coadministration of minocycline and indomethacin abrogates established paclitaxel-induced neuropathic thermal hyperalgesia in mice, and the potentiation of the antinociceptive effects of this combination involves the cannabinoid system.

  9. Biphasic effects of cannabinoids in anxiety responses: CB1 and GABA(B) receptors in the balance of GABAergic and glutamatergic neurotransmission.

    Science.gov (United States)

    Rey, Alejandro Aparisi; Purrio, Martin; Viveros, Maria-Paz; Lutz, Beat

    2012-11-01

    Biphasic effects of cannabinoids have been shown in processes such as feeding behavior, motor activity, motivational processes and anxiety responses. Using two different tests for the characterization of anxiety-related behavior (elevated plus-maze and holeboard), we first identified in wild-type C57BL/6N mice, two doses of the synthetic CB1 cannabinoid receptor agonist CP-55,940 with anxiolytic (1 μg/kg) and anxiogenic properties (50 μg/kg), respectively. To clarify the role of CB1 receptors in this biphasic effect, both doses were applied to two different conditional CB1 receptor knockout (KO) mouse lines, GABA-CB1-KO (CB1 receptor inactivation in forebrain GABAergic neurons) and Glu-CB1-KO (CB1 receptor inactivation in cortical glutamatergic neurons). We found that the anxiolytic-like effects of the low dose of cannabinoids are mediated via the CB1 receptor on cortical glutamatergic terminals, because this anxiolytic-like response was abrogated only in Glu-CB1-KO mice. On the contrary, the CB1 receptor on the GABAergic terminals is required to induce an anxiogenic-like effect under a high-dose treatment because of the fact that this effect was abolished specifically in GABA-CB1-KO mice. These experiments were carried out in both sexes, and no differences occurred with the doses tested in the mutant mice. Interestingly, the positive allosteric modulation of GABA(B) receptor with GS-39783 was found to largely abrogate the anxiogenic-like effect of the high dose of CP-55,940. Our results shed new light in further understanding the biphasic effects of cannabinoids at the molecular level and, importantly, pave the way for the development of novel anxiolytic cannabinoid drugs, which may have favorable effect profiles targeting the CB1 receptor on glutamatergic terminals.

  10. Cannabinoid CB1 receptors and ligands in vertebrate retina: Localization and function of an endogenous signaling system

    OpenAIRE

    1999-01-01

    CB1, a cannabinoid receptor enriched in neuronal tissue, was found in high concentration in retinas of rhesus monkey, mouse, rat, chick, goldfish, and tiger salamander by using a subtype-specific polyclonal antibody. Immunolabeling was detected in the two synaptic layers of the retina, the inner and outer plexiform layers, of all six species examined. In the outer plexiform layer, CB1 was located in and/or on cone pedicles and rod spherules. Labeling was detected in some amacrine cells of all...

  11. CB1 and CB2 receptors are novel molecular targets for Tamoxifen and 4OH-Tamoxifen

    Energy Technology Data Exchange (ETDEWEB)

    Prather, Paul L. [Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, 4301 W. Markham, Little Rock, AR 72205 (United States); FrancisDevaraj, FeAna; Dates, Centdrika R.; Greer, Aleksandra K.; Bratton, Stacie M. [Department of Biochemistry and Molecular Biology, College of Medicine, University of Arkansas for Medical Sciences, 4301 W. Markham, Little Rock, AR 72205 (United States); Ford, Benjamin M.; Franks, Lirit N. [Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, 4301 W. Markham, Little Rock, AR 72205 (United States); Radominska-Pandya, Anna, E-mail: RadominskaAnna@uams.edu [Department of Biochemistry and Molecular Biology, College of Medicine, University of Arkansas for Medical Sciences, 4301 W. Markham, Little Rock, AR 72205 (United States)

    2013-11-15

    Highlights: •Tamoxifen produces cytotoxicity via estrogen-receptor (ER) independent mechanisms. •Tamoxifen binds to CB1 and CB2 cannabinoid receptors and acts as an inverse agonist. •CB1 and CB2 receptors are novel molecular targets for Tamoxifen. •ER-independent effects for Tamoxifen may be mediated via CB1 and/or CB2 receptors. -- Abstract: Tamoxifen (Tam) is classified as a selective estrogen receptor modulator (SERM) and is used for treatment of patients with ER-positive breast cancer. However, it has been shown that Tam and its cytochrome P450-generated metabolite 4-hydroxy-Tam (4OH-Tam) also exhibit cytotoxic effects in ER-negative breast cancer cells. These observations suggest that Tam and 4OH-Tam can produce cytotoxicity via estrogen receptor (ER)-independent mechanism(s) of action. The molecular targets responsible for the ER-independent effects of Tam and its derivatives are poorly understood. Interestingly, similar to Tam and 4OH-Tam, cannabinoids have also been shown to exhibit anti-proliferative and apoptotic effects in ER-negative breast cancer cells, and estrogen can regulate expression levels of cannabinoid receptors (CBRs). Therefore, this study investigated whether CBRs might serve as novel molecular targets for Tam and 4OH-Tam. We report that both compounds bind to CB1 and CB2Rs with moderate affinity (0.9–3 μM). Furthermore, Tam and 4OH-Tam exhibit inverse activity at CB1 and CB2Rs in membrane preparations, reducing basal G-protein activity. Tam and 4OH-Tam also act as CB1/CB2R-inverse agonists to regulate the downstream intracellular effector adenylyl cyclase in intact cells, producing concentration-dependent increases in intracellular cAMP. These results suggest that CBRs are molecular targets for Tam and 4OH-Tam and may contribute to the ER-independent cytotoxic effects reported for these drugs. Importantly, these findings also indicate that Tam and 4OH-Tam might be used as structural scaffolds for development of novel

  12. Native CB1 receptor affinity, intrinsic activity and accumbens shell dopamine stimulant properties of third generation SPICE/K2 cannabinoids: BB-22, 5F-PB-22, 5F-AKB-48 and STS-135.

    Science.gov (United States)

    De Luca, Maria Antonietta; Castelli, M Paola; Loi, Barbara; Porcu, Alessandra; Martorelli, Mariella; Miliano, Cristina; Kellett, Kathryn; Davidson, Colin; Stair, Jacqueline L; Schifano, Fabrizio; Di Chiara, Gaetano

    2016-06-01

    In order to investigate the in vivo dopamine (DA) stimulant properties of selected 3rd generation Spice/K2 cannabinoids, BB-22, 5F-PB-22, 5F-AKB-48 and STS-135, their in vitro affinity and agonist potency at native rat and mice CB1 receptors was studied. The compounds bind with high affinity to CB1 receptors in rat cerebral cortex homogenates and stimulate CB1-induced [(35)S]GTPγS binding with high potency and efficacy. BB-22 and 5F-PB-22 showed the lowest Ki of binding to CB1 receptors (0.11 and 0.13 nM), i.e., 30 and 26 times lower respectively than that of JWH-018 (3.38 nM), and a potency (EC50, 2.9 and 3.7 nM, respectively) and efficacy (Emax, 217% and 203%, respectively) as CB1 agonists higher than JWH-018 (EC50, 20.2 nM; Emax, 163%). 5F-AKB-48 and STS-135 had higher Ki for CB1 binding, higher EC50 and lower Emax as CB1 agonists than BB-22 and 5F-PB-22 but still comparatively more favourable than JWH-018. The agonist properties of all the compounds were abolished or drastically reduced by the CB1 antagonist/inverse agonist AM251 (0.1 μM). No activation of G-protein was observed in CB1-KO mice. BB-22 (0.003-0.01 mg/kg i.v.) increased dialysate DA in the accumbens shell but not in the core or in the medial prefrontal cortex, with a bell shaped dose-response curve and an effect at 0.01 mg/kg and a biphasic time-course. Systemic AM251 (1.0 mg/kg i.p.) completely prevented the stimulant effect of BB-22 on dialysate DA in the NAc shell. All the other compounds increased dialysate DA in the NAc shell at doses consistent with their in vitro affinity for CB1 receptors (5F-PB-22, 0.01 mg/kg; 5F-AKB-48, 0.1 mg/kg; STS-135, 0.15 mg/kg i.v.). 3rd generation cannabinoids can be even more potent and super-high CB1 receptor agonists compared to JWH-018. Future research will try to establish if these properties can explain the high toxicity and lethality associated with these compounds.

  13. Detailed analysis of food-reinforced operant lever pressing distinguishes effects of a cannabinoid CB1 inverse agonist and dopamine D1 and D2 antagonists.

    Science.gov (United States)

    McLaughlin, P J; Winston, K M; Swezey, L A; Vemuri, V K; Makriyannis, A; Salamone, J D

    2010-07-01

    Overt similarities exist between the effects of systemic cannabinoid CB1 inverse agonists and dopamine (DA) antagonists on appetitive behavior. The present set of studies was undertaken to apply a fine-grained analysis of food-reinforced operant lever pressing in rats in order to compare the pattern of effects produced by administration of the CB1 inverse agonist AM 251 and those induced by the DA D1 antagonist SKF 83566, and the D2 antagonist raclopride. Three groups of rats were trained on a fixed-ratio 5 (FR5) schedule and administered these compounds over a range of doses expected to suppress responding. All three drugs produced a dose-related suppression of total lever pressing. In addition to main effects of dose, regression analyses were performed to determine which of several response timing- and rate-related variables correlated most strongly with overall responding in each group. It was found that total session time spent pausing from responding was significantly better at predicting responding in the AM 251 group, while both DA antagonists produced significantly stronger regression coefficients (versus AM 251) from fast responding measures. These results suggest that, while several similarities exist, CB1, D1, and D2 antagonists are not identical in their pattern of suppression of food-maintained lever pressing.

  14. Hydroxytyrosol Inhibits Cannabinoid CB1 Receptor Gene Expression in 3T3-L1 Preadipocyte Cell Line.

    Science.gov (United States)

    Tutino, Valeria; Orlando, Antonella; Russo, Francesco; Notarnicola, Maria

    2016-02-01

    The 3T3-L1 preadipocyte cell line is a well characterized cell model for studying the adipocyte status and the molecular mechanisms involved in differentiation of these cells. 3T3-L1 preadipocytes have the ability to synthesize and degrade endocannabinoid anandamide (AEA) and their differentiation into adipocytes increases the expression of cannabinoid (CB1) and PPAR-γ receptors. Clinically, the blocking stimulation of the endocannabinoid pathway has been one of the first approaches proposed to counteract the obesity and obesity-associated diseases (such as diabetes, metabolic syndrome and cancer). In this connection, here we studied in cultured 3T3-L1 pre-adipocytes the effects of n-3-PUFA, α-Linolenic acid (OM-3), n-6-PUFA, Linoleic acid (OM-6), and hydroxytyrosol (HT) on the expression of CB1 receptor gene and the adipogenesis-related genes PPAR-γ, Fatty Acid Synthase (FAS) and Lipoprotein Lipase (LPL). HT was able to inhibit 3T3-L1 cell differentiation by down-regulating cell proliferation and CB1 receptor gene expression. HT exhibited anti-adipogenic effects, whereas OM-3 and OM-6 exerted an inhibitory action on cell proliferation associated with an induction of the preadipocytes differentiation and CB1 receptor gene expression. Moreover, the expression of FAS and LPL genes resulted increased after treatment with both HT and OM-3 and OM-6. The present study points out that the intake of molecules such as HT, contained in extra virgin olive oil, may be considered also in view of antiobesity and antineoplastic properties by acting directly on the adipose tissue and modulating CB1 receptor gene transcription.

  15. Striatal adenosine A2A and cannabinoid CB1 receptors form functional heteromeric complexes that mediate the motor effects of cannabinoids.

    Science.gov (United States)

    Carriba, Paulina; Ortiz, Oskar; Patkar, Kshitij; Justinova, Zuzana; Stroik, Jessica; Themann, Andrea; Müller, Christa; Woods, Anima S; Hope, Bruce T; Ciruela, Francisco; Casadó, Vicent; Canela, Enric I; Lluis, Carme; Goldberg, Steven R; Moratalla, Rosario; Franco, Rafael; Ferré, Sergi

    2007-11-01

    The mechanism of action responsible for the motor depressant effects of cannabinoids, which operate through centrally expressed cannabinoid CB1 receptors, is still a matter of debate. In the present study, we report that CB1 and adenosine A2A receptors form heteromeric complexes in co-transfected HEK-293T cells and rat striatum, where they colocalize in fibrilar structures. In a human neuroblastoma cell line, CB1 receptor signaling was found to be completely dependent on A2A receptor activation. Accordingly, blockade of A2A receptors counteracted the motor depressant effects produced by the intrastriatal administration of a cannabinoid CB1 receptor agonist. These biochemical and behavioral findings demonstrate that the profound motor effects of cannabinoids depend on physical and functional interactions between striatal A2A and CB1 receptors.

  16. Sativex-like combination of phytocannabinoids is neuroprotective in malonate-lesioned rats, an inflammatory model of Huntington's disease: role of CB1 and CB2 receptors.

    Science.gov (United States)

    Valdeolivas, Sara; Satta, Valentina; Pertwee, Roger G; Fernández-Ruiz, Javier; Sagredo, Onintza

    2012-05-16

    We have investigated whether a 1:1 combination of botanical extracts enriched in either Δ(9)-tetrahydrocannabinol (Δ(9)-THC) or cannabidiol (CBD), which are the main constituents of the cannabis-based medicine Sativex, is neuroprotective in Huntington's disease (HD), using an experimental model of this disease generated by unilateral lesions of the striatum with the mitochondrial complex II inhibitor malonate. This toxin damages striatal neurons by mechanisms that primarily involve apoptosis and microglial activation. We monitored the extent of this damage and the possible preservation of the striatal parenchyma by treatment with a Sativex-like combination of phytocannabinoids using different histological and biochemical markers. Results were as follows: (i) malonate increased the volume of edema measured by in vivo NMR imaging and the Sativex-like combination of phytocannabinoids partially reduced this increase; (ii) malonate reduced the number of Nissl-stained cells, while enhancing the number of degenerating cells stained with FluoroJade-B, and the Sativex-like combination of phytocannabinoids reversed both effects; (iii) malonate caused a strong glial activation (i.e., reactive microglia labeled with Iba-1, and astrogliosis labeled with GFAP) and the Sativex-like combination of phytocannabinoids attenuated both responses; and (iv) malonate increased the expression of inducible nitric oxide synthase and the neurotrophin IGF-1, and both responses were attenuated after the treatment with the Sativex-like combination of phytocannabinoids. We also wanted to establish whether targets within the endocannabinoid system (i.e., CB(1) and CB(2) receptors) are involved in the beneficial effects induced in this model by the Sativex-like combination of phytocannabinoids. This we did using selective antagonists for both receptor types (i.e., SR141716 and AM630) combined with the Sativex-like phytocannabinoid combination. Our results indicated that the effects of this

  17. The dopamine and cannabinoid interaction in the modulation of emotions and cognition: Assessing the role of cannabinoid CB1 receptor in neurons expressing dopamine D1 receptors

    Directory of Open Access Journals (Sweden)

    Ana Luisa eTerzian

    2011-08-01

    Full Text Available Although cannabinoid CB1 receptors (CB1Rs are densely expressed in neurons expressing dopamine D1 receptors (D1Rs, it is not fully understood to what extent they modulate emotional behaviors. We used conditional CB1R knock-out animals lacking CB1Rs in neurons expressing D1R (D1-CB1-/- in order to answer this question. To elucidate the behavioral effects of CB1R deficiency in this specific neuronal subpopulation, we subjected D1-CB1-/- mice to a battery of behavioral tests which included exploration-based tests, depressive-like behavioral tests, social behavior and fear-related memory paradigms. D1-CB1-/- did not show any difference in the exploration-based paradigms such as open field, elevated plus maze or novel object investigation test, except for an increase in novelty-induced grooming. By contrast, they showed a mild anhedonia-like state as described by the slightly decreased preference for sweet solution, as compared to wild-type control (WT group. This decrease, however, could be observed only during the first day of exposure, thus suggesting increased neophobia as an alternative explanation. Accordingly, mutant mice performed normally in the forced swim test, a procedure widely used for evaluating behavioral despair in rodents. However, weak- to moderate anxiety-like phenotypes were evident when D1-CB1-/- mice were tested for social behavior. Most strikingly, D1-CB1-/- mice exhibited significantly increased contextual and auditory-cued fear, with attenuated within session extinction, suggesting that a specific reduction of endocannabinoid signaling in neurons expressing dopamine D1Rs is able to affect acute fear adaptation. These results provided first direct evidence for a cross-talk between dopaminergic D1Rs and endocannabinoid system in terms of controlling negative affect.

  18. Structure-activity relationships of substituted 1H-indole-2-carboxamides as CB1 receptor allosteric modulators.

    Science.gov (United States)

    Nguyen, Thuy; German, Nadezhda; Decker, Ann M; Li, Jun-Xu; Wiley, Jenny L; Thomas, Brian F; Kenakin, Terry P; Zhang, Yanan

    2015-05-01

    A series of substituted 1H-indole-2-carboxamides structurally related to compounds Org27569 (1), Org29647 (2) and Org27759 (3) were synthesized and evaluated for CB1 allosteric modulating activity in calcium mobilization assays. Structure-activity relationship studies showed that the modulation potency of this series at the CB1 receptor was enhanced by the presence of a diethylamino group at the 4-position of the phenyl ring, a chloro or fluoro group at the C5 position and short alkyl groups at the C3 position on the indole ring. The most potent compound (45) had an IC₅₀ value of 79 nM which is ∼2.5 and 10 fold more potent than the parent compounds 3 and 1, respectively. These compounds appeared to be negative allosteric modulators at the CB1 receptor and dose-dependently reduced the Emax of agonist CP55,940. These analogs may provide the basis for further optimization and use of CB1 allosteric modulators.

  19. The hypothermic response to bacterial lipopolysaccharide critically depends on brain CB1, but not CB2 or TRPV1, receptors.

    Science.gov (United States)

    Steiner, Alexandre A; Molchanova, Alla Y; Dogan, M Devrim; Patel, Shreya; Pétervári, Erika; Balaskó, Márta; Wanner, Samuel P; Eales, Justin; Oliveira, Daniela L; Gavva, Narender R; Almeida, M Camila; Székely, Miklós; Romanovsky, Andrej A

    2011-05-01

    Hypothermia occurs in the most severe cases of systemic inflammation, but the mechanisms involved are poorly understood. This study evaluated whether the hypothermic response to bacterial lipopolysaccharide (LPS) is modulated by the endocannabinoid anandamide(AEA) and its receptors: cannabinoid-1 (CB1), cannabinoid-2 (CB2) and transient receptor potential vanilloid-1 (TRPV1). In rats exposed to an ambient temperature of 22◦C, a moderate dose of LPS (25 - 100 μg kg−1 I.V.) induced a fall in body temperature with a nadir at ∼100 minpostinjection. This response was not affected by desensitization of intra-abdominal TRPV1 receptors with resiniferatoxin (20 μg kg - 1 I.P.), by systemic TRPV1 antagonism with capsazepine(40mg kg−1 I.P.), or by systemic CB2 receptor antagonism with SR144528 (1.4 mg kg−1 I.P.).However, CB1 receptor antagonism by rimonabant (4.6mg kg−1 I.P.) or SLV319 (15mg kg−1 I.P.)blocked LPS hypothermia. The effect of rimonabant was further studied. Rimonabant blocked LPS hypothermia when administered I.C.V. at a dose (4.6 μg) that was too low to produce systemic effects. The blockade of LPS hypothermia by I.C.V. rimonabant was associated with suppression of the circulating level of tumour necrosis factor-α. In contrast to rimonabant,the I.C.V. administration of AEA (50 μg) enhanced LPS hypothermia. Importantly, I.C.V. AEAdid not evoke hypothermia in rats not treated with LPS, thus indicating that AEA modulates LPS-activated pathways in the brain rather than thermo effector pathways. In conclusion, the present study reveals a novel, critical role of brain CB1 receptors in LPS hypothermia. Brain CB1 receptors may constitute a new therapeutic target in systemic inflammation and sepsis.

  20. Effect of social isolation on CB1 and D2 receptor and fatty acid amide hydrolase expression in rats.

    Science.gov (United States)

    Malone, D T; Kearn, C S; Chongue, L; Mackie, K; Taylor, D A

    2008-03-03

    Rearing rats in isolation has been shown to produce behavioral and neurochemical alterations similar to those observed in psychoses such as schizophrenia. Also, a dysregulation in both the endocannabinoid and dopaminergic systems has been implicated in schizophrenia. The aim of this study was to determine if there are differences in CB1 receptor and fatty acid amide hydrolase (FAAH) protein expression, as well as D2 dopamine receptor expression in different brain regions in rats reared in different environmental conditions. Twenty-one-day-old male Sprague-Dawley rats were either reared in individual cages (isolated rats) or in group cages of six per cage (group-housed rats) for 8 weeks. Quantitative fluorescence immunohistochemistry was performed on brain slices using antibodies specific to the CB1 or D2 receptor, or the enzyme FAAH. Raising rats in isolation led to a significant decrease in CB1 receptor expression in the caudate putamen and the amygdala, a significant increase in FAAH expression in the caudate putamen and the nucleus accumbens core and shell, and no significant change in D2 receptor expression in any region studied. These results indicate that the endocannabinoid system is altered in an animal model of aspects of psychosis. This implies that rearing rats under different housing conditions may provide new insight into the role of the endocannabinoid system in the development of psychoses.

  1. Cannabinoid receptors 1 and 2 (CB1 and CB2), their distribution, ligands and functional involvement in nervous system structures--a short review.

    Science.gov (United States)

    Svízenská, Ivana; Dubový, Petr; Sulcová, Alexandra

    2008-10-01

    In the last 25 years data has grown exponentially dealing with the discovery of the endocannabinoid system consisting of specific cannabinoid receptors, their endogenous ligands, and enzymatic systems of their biosynthesis and degradation. Progress is being made in the development of novel agonists and antagonists with receptor subtype selectivity which should help in providing a greater understanding of the physiological role of the endocannabinoid system and perhaps also in a broad number of pathologies. This could lead to advances with important therapeutic potential of drugs modulating activity of endocannabinoid system as hypnotics, analgesics, antiemetics, antiasthmatics, antihypertensives, immunomodulatory drugs, antiphlogistics, neuroprotective agents, antiepileptics, agents influencing glaucoma, spasticity and other "movement disorders", eating disorders, alcohol withdrawal, hepatic fibrosis, bone growth, and atherosclerosis. The aim of this review is to highlight distribution of the CB1 and CB2 receptor subtypes in the nervous system and functional involvement of their specific ligands.

  2. CB1 receptor activation in the rat paraventricular nucleus induces bi-directional cardiovascular effects via modification of glutamatergic and GABAergic neurotransmission.

    Science.gov (United States)

    Grzęda, Emilia; Schlicker, Eberhard; Toczek, Marek; Zalewska, Iwona; Baranowska-Kuczko, Marta; Malinowska, Barbara

    2017-01-01

    We have shown previously that the cannabinoid receptor agonist CP55940 microinjected into the paraventricular nucleus of the hypothalamus (PVN) of urethane-anaesthetized rats induces depressor and pressor cardiovascular effects in the absence and presence of the CB1 antagonist AM251, respectively. The aim of our study was to examine whether the hypotension and/or hypertension induced by CP55940 given into the PVN results from its influence on glutamatergic and GABAergic neurotransmission. CP55940 was microinjected into the PVN of urethane-anaesthetized rats twice (S1 and S2, 20 min apart). Antagonists of the following receptors, NMDA (MK801), β2-adrenergic (ICI118551), thromboxane A2-TP (SQ29548), angiotensin II-AT1 (losartan) or GABAA (bicuculline), or the NO synthase inhibitor L-NAME were administered intravenously 5 min before S2 alone or together with AM251. The CP55940-induced hypotension was reversed into a pressor response by AM251, bicuculline and L-NAME, but not by the other antagonists. The CP55940-induced pressor effect examined in the presence of AM251 was completely reversed by losartan, reduced by about 50-60 % by MK801, ICI118551 and SQ29548, prevented by bilateral adrenalectomy but not modified by bicuculline and L-NAME. Parallel, but smaller, changes in heart rate accompanied the changes in blood pressure. The bi-directional CB1 receptor-mediated cardiovascular effects of cannabinoids microinjected into the PVN of anaesthetized rats depend on stimulatory glutamatergic and inhibitory GABAergic inputs to the sympathetic tone; the glutamatergic input is related to AT1, TP and β2-adrenergic receptors and catecholamine release from the adrenal medulla whereas the GABAergic input is reinforced by NO.

  3. Effects of glucagon-like peptide-1 receptor stimulation and blockade on food consumption and body weight in rats treated with a cannabinoid CB1 receptor agonist WIN 55,212-2

    Science.gov (United States)

    Radziszewska, Elżbieta; Bojanowska, Ewa

    2013-01-01

    Background Glucagon-like peptide-1 (GLP-1) and endocannabinoids are involved in appetite control. Recently we have demonstrated that cannabinoid (CB)1 receptor antagonist and GLP-1 receptor agonist synergistically suppress food intake in the rat. The aim of the present study was to determine the effects of GLP-1 receptor stimulation or blockade on feeding behavior in rats treated with WIN 55,212-2, a CB1 receptor agonist. Material/Methods Experiments were performed on adult male Wistar rats. In the first experiment the effects of increasing doses (0.5–4.0 mg/kg) of WIN 55,212-2 injected intraperitoneally on 24-hour food consumption were tested. In further experiments a GLP-1 receptor antagonist, exendin (9-39), and WIN 55,212-2 or a GLP-1 receptor agonist, exendin-4, and WIN 55,212-2 were injected intraperitoneally at subthreshold doses (that alone did not change food intake and body weight) to investigate whether these agents may interact to affect food intake in rats. Results WIN 55,212-2 administered at low doses (0.5–2 mg/kg) did not markedly change 24-hour food consumption; however, at the highest dose, daily food intake was inhibited. Combined administration of WIN 55,212-2 and exendin (9-39) did not change the amount of food consumed compared to either the control group or to each agent injected alone. Combined injection of WIN 55,212-2 and exendin-4 at subthreshold doses resulted in a significant decrease in food intake and body weight in rats. Conclusions Stimulation of the peripheral CB1 receptor by its agonist WIN 55,212-2 can induce anorexigenic effects or potentiate, even at a subthreshold dose, the effects of exendin-4, a known anorectic agent. Hence, this dual action of the cannabinoid system should be considered in the medical use of CB1 agonists. PMID:23291632

  4. Enhanced Glutamatergic Synaptic Plasticity in the Hippocampal CA1 Field of Food-Restricted Rats: Involvement of CB1 Receptors.

    Science.gov (United States)

    Talani, Giuseppe; Licheri, Valentina; Biggio, Francesca; Locci, Valentina; Mostallino, Maria Cristina; Secci, Pietro Paolo; Melis, Valentina; Dazzi, Laura; Carta, Gianfranca; Banni, Sebastiano; Biggio, Giovanni; Sanna, Enrico

    2016-04-01

    The endogenous endocannabinoid system has a crucial role in regulating appetite and feeding behavior in mammals, as well as working memory and reward mechanisms. In order to elucidate the possible role of cannabinoid type-1 receptors (CB1Rs) in the regulation of hippocampal plasticity in animals exposed to food restriction (FR), we limited the availability of food to a 2-h daily period for 3 weeks in Sprague-Dawley rats. FR rats showed a higher long-term potentiation at hippocampal CA1 excitatory synapses with a parallel increase in glutamate release when compared with animals fed ad libitum. FR rats showed a significant increase in the long-term spatial memory determined by Barnes maze. FR was also associated with a decreased inhibitory effect of the CB1R agonist win55,212-2 on glutamatergic field excitatory postsynaptic potentials, together with a decrease in hippocampal CB1R protein expression. In addition, hippocampal brain-derived neurotrophic factor protein levels and mushroom dendritic spine density were significantly enhanced in FR rats. Altogether, our data suggest that alterations of hippocampal CB1R expression and function in FR rats are associated with dendritic spine remodeling and functional potentiation of CA1 excitatory synapses, and these findings are consistent with increasing evidence supporting the idea that FR may improve cognitive functions.

  5. Immunohistochemical localization of CB1 cannabinoid receptors in frontal cortex and related limbic areas in obese Zucker rats: effects of chronic fluoxetine treatment.

    Science.gov (United States)

    Zarate, J; Churruca, I; Echevarría, E; Casis, L; López de Jesús, M; Saenz del Burgo, L; Sallés, J

    2008-10-21

    In the present study, we report on the application of two specific polyclonal antibodies to different intracellular domains of the CB1 cannabinoid receptor to define the expression of the neural CB1 cannabinoid receptor at the histochemical level in frontal cortex and related limbic areas of the obese Zucker rats. Higher levels of CB1 receptor expression in frontal, cingulated and piriform cortex, without differences in temporal, parietal and occipital cortex, were observed in obese Zucker rats, with respect to their lean littermates. CB1 phosphorylated receptor (CB1-P) levels were also higher in frontal, temporal, parietal and occipital cortex in obese rats with respect to lean controls. Potential involvement of brain cortical CB1 cannabinoid receptors in the long-term effects of fluoxetine was studied. Experimental animals were administered with fluoxetine (10 mg/kg, i.p.) daily for 3 weeks, whereas the control group was given 0.9% NaCl solution. In obese Zucker rats, a significant decrease in CB1 receptor levels, measured by western blot, was observed in brain cortex after fluoxetine treatment. Immunostaining for CB1 receptor expression was also carried out, showing a significant decrease in the density of neural cells positive for CB1 receptor in frontal, cingulate and piriform cortex, without changes in parietal, temporal and occipital regions. Regional prosencephalic immunostaining for CB1-P receptor level showed a significant decrease in the density of stained neural cells in frontal, temporal and parietal cortex, without changes in cingulated, piriform and occipital cortex. These results suggest the involvement of endocannabinoid system in the chronic effects of fluoxetine, especially in the frontal cortex.

  6. Early endogenous activation of CB1 and CB2 receptors after spinal cord injury is a protective response involved in spontaneous recovery.

    Directory of Open Access Journals (Sweden)

    Angel Arevalo-Martin

    Full Text Available Spinal cord injury (SCI induces a cascade of processes that may further expand the damage (secondary injury or, alternatively, may be part of a safeguard response. Here we show that after a moderate-severe contusive SCI in rats there is a significant and very early increase in the spinal cord content of the endocannabinoids 2-arachidonoylglycerol (2-AG and arachidonoyl ethanolamide (anandamide, AEA. Since 2-AG and AEA act through CB1 and CB2 cannabinoid receptors, we administered at 20 minutes after lesion a single injection of their respective antagonists AM281 and AM630 alone or in combination to block the effects of this early endocannabinoid accumulation. We observed that AM281, AM630 or AM281 plus AM630 administration impairs the spontaneous motor recovery of rats according to the Basso-Beattie-Bresnahan (BBB locomotor scale. However, blockade of CB1, CB2 or both receptors produced different effects at the histopathological level. Thus, AM630 administration results at 90 days after lesion in increased MHC-II expression by spinal cord microglia/monocytes and reduced number of serotoninergic fibres in lumbar spinal cord (below the lesion. AM281 exerted the same effects but also increased oedema volume estimated by MRI. Co-administration of AM281 and AM630 produced the effects observed with the administration of either AM281 or AM630 and also reduced white matter and myelin preservation and enhanced microgliosis in the epicentre. Overall, our results suggest that the endocannabinoids acting through CB1 and CB2 receptors are part of an early neuroprotective response triggered after SCI that is involved in the spontaneous recovery after an incomplete lesion.

  7. Early endogenous activation of CB1 and CB2 receptors after spinal cord injury is a protective response involved in spontaneous recovery.

    Science.gov (United States)

    Arevalo-Martin, Angel; Garcia-Ovejero, Daniel; Sierra-Palomares, Yolanda; Paniagua-Torija, Beatriz; Gonzalez-Gil, Ines; Ortega-Gutierrez, Silvia; Molina-Holgado, Eduardo

    2012-01-01

    Spinal cord injury (SCI) induces a cascade of processes that may further expand the damage (secondary injury) or, alternatively, may be part of a safeguard response. Here we show that after a moderate-severe contusive SCI in rats there is a significant and very early increase in the spinal cord content of the endocannabinoids 2-arachidonoylglycerol (2-AG) and arachidonoyl ethanolamide (anandamide, AEA). Since 2-AG and AEA act through CB1 and CB2 cannabinoid receptors, we administered at 20 minutes after lesion a single injection of their respective antagonists AM281 and AM630 alone or in combination to block the effects of this early endocannabinoid accumulation. We observed that AM281, AM630 or AM281 plus AM630 administration impairs the spontaneous motor recovery of rats according to the Basso-Beattie-Bresnahan (BBB) locomotor scale. However, blockade of CB1, CB2 or both receptors produced different effects at the histopathological level. Thus, AM630 administration results at 90 days after lesion in increased MHC-II expression by spinal cord microglia/monocytes and reduced number of serotoninergic fibres in lumbar spinal cord (below the lesion). AM281 exerted the same effects but also increased oedema volume estimated by MRI. Co-administration of AM281 and AM630 produced the effects observed with the administration of either AM281 or AM630 and also reduced white matter and myelin preservation and enhanced microgliosis in the epicentre. Overall, our results suggest that the endocannabinoids acting through CB1 and CB2 receptors are part of an early neuroprotective response triggered after SCI that is involved in the spontaneous recovery after an incomplete lesion.

  8. Palmitoylation of cysteine 415 of CB1 receptor affects ligand-stimulated internalization and selective interaction with membrane cholesterol and caveolin 1.

    Science.gov (United States)

    Oddi, Sergio; Stepniewski, Tomasz Maciej; Totaro, Antonio; Selent, Jana; Scipioni, Lucia; Dufrusine, Beatrice; Fezza, Filomena; Dainese, Enrico; Maccarrone, Mauro

    2017-02-12

    We previously demonstrated that CB1 receptor is palmitoylated at cysteine 415, and that such a post-translational modification affects its biological activity. To assess the molecular mechanisms responsible for modulation of CB1 receptor function by S-palmitoylation, in this study biochemical and morphological approaches were paralleled with computational analyses. Molecular dynamics simulations suggested that this acyl chain stabilizes helix 8 as well as the interaction of CB1 receptor with membrane cholesterol. In keeping with these in silico data, experimental results showed that the non-palmitoylated CB1 receptor was unable to interact efficaciously with caveolin 1, independently of its activation state. Moreover, in contrast with the wild-type receptor, the lack of S-palmitoylation in the helix 8 made the mutant CB1 receptor completely irresponsive to agonist-induced effects in terms of both lipid raft partitioning and receptor internalization. Overall, our results support the notion that palmitoylation of cysteine 415 modulates the conformational state of helix 8 and influences the interactions of CB1 receptor with cholesterol and caveolin 1, suggesting that the palmitoyl chain may serve as a functional interface for CB1 receptor localization and function.

  9. Comparison of the D2 Receptor Regulation and Neurotoxicant Susceptibility of Nigrostriatal Dopamine Neurons in Wild-Type and CB1/CB2 Receptor Knockout Mice

    OpenAIRE

    Simkins, Tyrell J.; Janis, Kelly L.; McClure, Alison K.; Behrouz, Bahareh; Pappas, Samuel S.; Lehner, Andreas; Kaminski, Norbert E.; Goudreau, John L.; Lookingland, Keith J.; Kaplan, Barbara L. F.

    2012-01-01

    Motor dysfunctions of Parkinson Disease (PD) are due to the progressive loss of midbrain nigrostriatal dopamine (NSDA) neurons. Evidence suggests a role for cannabinoid receptors in the neurodegeneration of these neurons following neurotoxicant-induced injury. This work evaluates NSDA neurons in CB1/CB2 knockout (KO) mice and tests the hypothesis that CB1/CB2 KO mice are more susceptible to neurotoxicant exposure. NSDA neuronal indices were assessed using unbiased stereological cell counting,...

  10. The effects of targeted deletion of cannabinoid receptors CB1 and CB2 on intranasal sensitization and challenge with adjuvant-free ovalbumin.

    Science.gov (United States)

    Kaplan, Barbara L F; Lawver, Jody E; Karmaus, Peer W F; Ngaotepprutaram, Thitirat; Birmingham, Neil P; Harkema, Jack R; Kaminski, Norbert E

    2010-04-01

    The mechanisms by which cannabinoid receptors CB(1) and CB(2) modulate immune function are not fully elucidated. Critical tools for the determination of the role of both receptors in the immune system are CB(1)/CB(2) double null mice (CB(1)/CB(2) null), and previous studies have shown that CB(1)/CB(2) null mice exhibit exaggerated responses to various immunological stimuli. The objective of these studies was to determine the magnitude to which CB(1)/CB(2) null mice responded to the respiratory allergen ovalbumin (OVA) as compared with wild-type C57BL/6 mice. The authors determined that in the absence of adjuvant, both wild-type and CB(1)/CB(2) null mice mounted a marked response to intranasally instilled OVA as assessed by inflammatory cell infiltrate in the bronchoalveolar lavage fluid (BALF), eosinophilia, induction of mucous cell metaplasia, and IgE production. Many of the endpoints measured in response to OVA were similar in wild-type versus CB(1)/CB(2) null mice, with exceptions being modest reductions in OVA-induced IgE and attenuation of BALF neutrophilia in CB(1)/CB(2) null mice as compared with wild-type mice. These results suggest that T-cell responses are not universally exaggerated in CB(1)/CB(2) null mice.

  11. Neonatal DSP-4 treatment modifies antinociceptive effects of the CB1 receptor agonist methanandamide in adult rats.

    Science.gov (United States)

    Korossy-Mruk, Eva; Kuter, Katarzyna; Nowak, Przemysław; Szkilnik, Ryszard; Rykaczewska-Czerwinska, Monika; Kostrzewa, Richard M; Brus, Ryszard

    2013-01-01

    To study the influence of the central noradrenergic system on antinociceptive effects mediated by the CB(1)-receptor agonist methanandamide, intact rats were contrasted with rats in which noradrenergic nerves were largely destroyed shortly after birth with the neurotoxin DSP-4 [N-(-2-chloroethyl)-N-ethyl-2-bromobenzylamine (50 mg/kg sc × 2, P1 and P3); zimelidine (10 mg/kg sc, 30 min pretreatment, selective serotonin reuptake inhibitor). When rats attained 10 weeks of age, monoamine and their metabolite concentrations were determined in the frontal cortex, thalamus, and spinal cord by an HPLC/ED method. Antinociceptive effects after methanandamide (10 mg/kg ip) apply were evaluated by a battery of tests. In addition, immunohistochemistry and densitometric analysis of the cannabinoid CB(1) receptor in the rat brain was performed. DSP-4 lesioning was associated with a reduction in norepinephrine content of the frontal cortex (>90 %) and spinal cord (>80 %) with no changes in the thalamus. Neonatal DSP-4 treatment produced a significant reduction in the antinociceptive effect of methanandamide in the tail-immersion test, hot-plate test and writhing tests. In the paw pressure and formalin hind paw tests results were ambiguous. These findings indicate that the noradrenergic system exerts a prominent influence on analgesia acting via the cannabinoid system in brain, without directly altering CB(1) receptor density in the brain.

  12. Endocannabinoid CB1 Receptor Mediated Rises in Ca2+ and Depolarization-Induced Suppression of Inhibition within the Laterodorsal Tegmental Nucleus

    DEFF Research Database (Denmark)

    Soni, Neeraj; Kohlmeier, Kristi Anne

    2016-01-01

    Cannabinoid type 1 receptors (CB1Rs) are functionally active within the laterodorsal tegmental nucleus (LDT), which is critically involved in control of rapid eye movement sleep, cortical arousal, and motivated states. To further characterize the cellular consequences of activation of CB1Rs...

  13. CB1 and CB2 receptors are novel molecular targets for Tamoxifen and 4OH-Tamoxifen.

    Science.gov (United States)

    Prather, Paul L; FrancisDevaraj, FeAna; Dates, Centdrika R; Greer, Aleksandra K; Bratton, Stacie M; Ford, Benjamin M; Franks, Lirit N; Radominska-Pandya, Anna

    2013-11-15

    Tamoxifen (Tam) is classified as a selective estrogen receptor modulator (SERM) and is used for treatment of patients with ER-positive breast cancer. However, it has been shown that Tam and its cytochrome P450-generated metabolite 4-hydroxy-Tam (4OH-Tam) also exhibit cytotoxic effects in ER-negative breast cancer cells. These observations suggest that Tam and 4OH-Tam can produce cytotoxicity via estrogen receptor (ER)-independent mechanism(s) of action. The molecular targets responsible for the ER-independent effects of Tam and its derivatives are poorly understood. Interestingly, similar to Tam and 4OH-Tam, cannabinoids have also been shown to exhibit anti-proliferative and apoptotic effects in ER-negative breast cancer cells, and estrogen can regulate expression levels of cannabinoid receptors (CBRs). Therefore, this study investigated whether CBRs might serve as novel molecular targets for Tam and 4OH-Tam. We report that both compounds bind to CB1 and CB2Rs with moderate affinity (0.9-3 μM). Furthermore, Tam and 4OH-Tam exhibit inverse activity at CB1 and CB2Rs in membrane preparations, reducing basal G-protein activity. Tam and 4OH-Tam also act as CB1/CB2R-inverse agonists to regulate the downstream intracellular effector adenylyl cyclase in intact cells, producing concentration-dependent increases in intracellular cAMP. These results suggest that CBRs are molecular targets for Tam and 4OH-Tam and may contribute to the ER-independent cytotoxic effects reported for these drugs. Importantly, these findings also indicate that Tam and 4OH-Tam might be used as structural scaffolds for development of novel, efficacious, non-toxic cancer drugs acting via CB1 and/or CB2Rs.

  14. Cannabinoid CB1 receptors of the dorsal hippocampus are important for induction of conditioned place preference (CPP) but do not change morphine CPP.

    Science.gov (United States)

    Zarrindast, Mohammad-Reza; Nouri, Maryam; Ahmadi, Shamseddin

    2007-08-13

    Interactions between cannabinoid and opioid systems have been reported in many studies. In the present study, we have investigated influence of cannabinoid CB1 receptor mechanism on the acquisition of conditioned place preference (CPP) induced by morphine in male Wistar rats. The cannabinoid CB1 receptor agonist (WIN55,212-2) and antagonist (AM251) were injected bilaterally into the dorsal hippocampus. Morphine and naloxone were injected subcutaneously (s.c.). The conditioning treatments with injections of morphine (6 and 9 mg/kg) induced a CPP for the drug-associated place. When administered into the dorsal hippocampus, WIN55,212-2 (1 microg/rat) induced CPP, but significantly did not alter CPP induced by a sub-effective dose of morphine (3 mg/kg). Moreover, administration of different doses of AM251 (50 and 100 ng/rat) into the dorsal hippocampus induced CPP, while did not change CPP by the sub-effective dose of morphine. Naloxone alone (1 mg/kg) induced conditioned place aversion (CPA). The drug (0.5 and 1 mg/kg) also caused CPA when co-administered with WIN55,212-2 (1 microg/rat). These results suggest that endocannabinoid system in the dorsal hippocampus is important for the CPP paradigm. However, agents did not alter morphine-induced CPP.

  15. 大麻素CB1受体对大鼠视网膜神经节细胞诱发动作电位的作用%Activation of cannabinoid CB1 receptors modulates evoked action potentials in rat retinal ganglion cells

    Institute of Scientific and Technical Information of China (English)

    蒋淑霞; 李倩; 王霄汉; 李芳; 王中峰

    2013-01-01

    Activation of cannabinoid CB1 receptors (CB 1Rs) regulates a variety of physiological functions in the vertebrate retina through modulating various types of ion channels.The aim of the present study was to investigate the effects of this receptor on cell excitability of rat retinal ganglion cells (RGCs) in retinal slices using whole-cell patch-clamp techniques.The results showed that under current-clamped condition perfusing WIN55212-2 (WIN,5 μmol/L),a CB1R agonist,did not significantly change the spontaneous firing frequency and resting membrane potential of RGCs.In the presence of cocktail synaptic blockers,including excitatory postsynaptic receptor blockers CNQX and D-APV,and inhibitory receptor blockers bicuculline and strychnine,perfusion of WIN (5 μmol/L)hardly changed the frequencies of evoked action potentials by a series of positive current injection (from +10 to +100 pA).Phaseplane plot analysis showed that both average threshold voltage for triggering action potential and delay time to reach threshold voltage were not affected by WIN.However,WIN significantly decreased +dV/dtmax and-dV/dtmax of action potentials,suggestive of reduced rising and descending velocities of action potentials.The effects of WIN were reversed by co-application of SR141716,a CB1R selective antagonist.Moreover,WIN did not influence resting membrane potential of RGCs with synaptic inputs being blocked.These results suggest that activation of CB1Rs may regulate intrinsic excitability of rat RGCs through modulating evoked action potentials.%激活大麻素CB1受体(CB1Rs)通过调控多种离子通道,从而调节脊椎动物视网膜的功能.本文旨在利用膜片钳全细胞记录技术,在大鼠视网膜薄片上研究CB1Rs对神经节细胞兴奋性的作用.结果显示,在电流钳制状态下,灌流CB1R激动剂WIN55212-2 (WIN,5μmol/L)对神经节细胞的自发动作电位发放频率和静息膜电位均没有显著影响.在灌流液中加入CNQX,D-APV,bicuculline

  16. CB1 Cannabinoid Receptor-Dependent Activation of mTORC1/Pax6 Signaling Drives Tbr2 Expression and Basal Progenitor Expansion in the Developing Mouse Cortex.

    Science.gov (United States)

    Díaz-Alonso, Javier; Aguado, Tania; de Salas-Quiroga, Adán; Ortega, Zaira; Guzmán, Manuel; Galve-Roperh, Ismael

    2015-09-01

    The CB1 cannabinoid receptor regulates cortical progenitor proliferation during embryonic development, but the molecular mechanism of this action remains unknown. Here, we report that CB1-deficient mouse embryos show premature cell cycle exit, decreased Pax6- and Tbr2-positive cell number, and reduced mammalian target of rapamycin complex 1 (mTORC1) activation in the ventricular and subventricular cortical zones. Pharmacological stimulation of the CB1 receptor in cortical slices and progenitor cell cultures activated the mTORC1 pathway and increased the number of Pax6- and Tbr2-expressing cells. Likewise, acute CB1 knockdown in utero reduced mTORC1 activation and cannabinoid-induced Tbr2-positive cell generation. Luciferase reporter and chromatin immunoprecipitation assays revealed that the CB1 receptor drives Tbr2 expression downstream of Pax6 induction in an mTORC1-dependent manner. Altogether, our results demonstrate that the CB1 receptor tunes dorsal telencephalic progenitor proliferation by sustaining the transcriptional activity of the Pax6-Tbr2 axis via the mTORC1 pathway, and suggest that alterations of CB1 receptor signaling, by producing the missexpression of progenitor identity determinants may contribute to neurodevelopmental alterations.

  17. Delta(9)-tetrahydrocannabinol prolongs the immobility time in the mouse forced swim test: involvement of cannabinoid CB(1) receptor and serotonergic system.

    Science.gov (United States)

    Egashira, Nobuaki; Matsuda, Tomomi; Koushi, Emi; Higashihara, Fuminori; Mishima, Kenichi; Chidori, Shozo; Hasebe, Nobuyoshi; Iwasaki, Katsunori; Nishimura, Ryoji; Oishi, Ryozo; Fujiwara, Michihiro

    2008-07-28

    In the present study, we investigated the effect of Delta(9)-tetrahydrocannabinol (THC), the principal psychoactive component of marijuana, on immobility time during the forced swim test. THC (2 and 6 mg/kg, i.p.) significantly prolonged the immobility time. In addition, THC at the same doses did not significantly affect locomotor activity in the open-field test. The selective cannabinoid CB(1) receptor antagonist rimonabant (3 mg/kg, i.p.) significantly reduced the enhancement of immobility by THC (6 mg/kg). Similarly, the selective serotonin (5-HT) reuptake inhibitor (SSRI) citalopram (10 mg/kg, i.p.) and 5-HT(1A/7) receptor agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT, 0.3 mg/kg, i.p.) significantly reduced this THC-induced effect. Moreover, the selective 5-HT(1A) receptor antagonist N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) cyclohexane carboxamide dihydrochloride (WAY100635, 1 mg/kg, i.p.) and the postsynaptic 5-HT(1A) receptor antagonist MM-77 (0.1 mg/kg, i.p.) reversed this reduction effect of 8-OH-DPAT (0.3 mg/kg). In contrast, the selective 5-HT(7) receptor antagonist (R)-3-[2-[2-(4-methylpiperidin-1-yl)ethyl]pyrrolidine-1-sulfonyl]phenol hydrochloride (SB269970) had no effect on this reduction effect of 8-OH-DPAT. WAY100635 (1 mg/kg) also reversed the reduction effect of citalopram (10 mg/kg). These findings suggest that the 5-HT(1A) receptors are involved in THC-induced enhancement of immobility.

  18. Non-CB1, non-CB2 receptors for endocannabinoids, plant cannabinoids, and synthetic cannabimimetics: focus on G-protein-coupled receptors and transient receptor potential channels.

    Science.gov (United States)

    De Petrocellis, Luciano; Di Marzo, Vincenzo

    2010-03-01

    The molecular mechanism of action of Delta(9)-tetrahydrocannabinol (THC), the psychotropic constituent of Cannabis, has been a puzzle during the three decades separating its characterization, in 1964, and the cloning, in the 1990s, of cannabinoid CB1 and CB2 receptors. However, while these latter proteins do mediate most of the pharmacological actions of THC, they do not seem to act as receptors for other plant cannabinoids (phytocannabinoids), nor are they the unique targets of the endogenous lipids that were originally identified in animals as agonists of CB1 and CB2 receptors, and named endocannabinoids. Over the last decade, several potential alternative receptors for phytocannabinoids, endocannabinoids, and even synthetic cannabimimetics, have been proposed, often based uniquely on pharmacological evidence obtained in vitro. In particular, the endocannabinoid anandamide, and the other most abundant Cannabis constituent, cannabidiol, seem to be the most "promiscuous" of these compounds. In this article, we review the latest data on the non-CB1, non-CB2 receptors suggested so far for endocannabinoids and plant or synthetic cannabinoids, and lay special emphasis on uncharacterized or orphan G-protein-coupled receptors as well as on transient receptor potential channels.

  19. Comparison of the D2 receptor regulation and neurotoxicant susceptibility of nigrostriatal dopamine neurons in wild-type and CB1/CB2 receptor knockout mice.

    Science.gov (United States)

    Simkins, Tyrell J; Janis, Kelly L; McClure, Alison K; Behrouz, Bahareh; Pappas, Samuel S; Lehner, Andreas; Kaminski, Norbert E; Goudreau, John L; Lookingland, Keith J; Kaplan, Barbara L F

    2012-09-01

    Motor dysfunctions of Parkinson Disease (PD) are due to the progressive loss of midbrain nigrostriatal dopamine (NSDA) neurons. Evidence suggests a role for cannabinoid receptors in the neurodegeneration of these neurons following neurotoxicant-induced injury. This work evaluates NSDA neurons in CB1/CB2 knockout (KO) mice and tests the hypothesis that CB1/CB2 KO mice are more susceptible to neurotoxicant exposure. NSDA neuronal indices were assessed using unbiased stereological cell counting, high pressure liquid chromatography coupled with electrochemical detection or mass spectrometry, and Western blot. Results reveal that CB1 and CB2 cannabinoid receptor signaling is not necessary for the maintenance of a normally functioning NSDA neuronal system. Mice lacking CB1 and CB2 receptors were found to be equally susceptible to the neurotoxicant 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine (MPTP). These studies support the use of CB1/CB2 KO mice for investigating the cannabinoid receptor-mediated regulation of the NSDA neuronal system in models of PD.

  20. The effects of charge-neutralizing mutation D6.30N on the functions of CB1 and CB2 cannabinoid receptors.

    Science.gov (United States)

    Nebane, Ntsang M; Kellie, Brandon; Song, Zhao-Hui

    2006-10-02

    Charge-neutralizing mutation D6.30N of the human cannabinoid receptor subtype 1 (CB1) and cannabinoid receptor subtype 2 (CB2) cannabinoid receptors was made to test two hypotheses: (1) D6.30 may be crucial for the functions of CB1 and CB2 receptors. (2) D6.30 may participate in an ionic lock with R3.50 that keeps the receptors in an inactive conformation. Specific ligand binding and ligand-induced inhibition of forskolin-stimulated cAMP accumulation were observed with human embryonic kidney epithelial cell line (HEK293) cells expressing wild-type CB1 and CB2, as well as CB1D6.30N and CB2D6.30N mutant receptors. There was however a decrease in maximum response of the mutant receptors compared to their wild-type counterparts, suggesting that D6.30 is essential for full activation of both CB1 and CB2 receptors. Both CB1D6.30N and CB2D6.30N demonstrated a level of constitutive activity no greater than that of their wild-type counterparts, indicating that either D6.30 does not participate in a salt bridge with R3.50, or the salt bridge is not critical for keeping cannabinoid receptors in the inactive conformation.

  1. Long-term consequences of URB597 administration during adolescence on cannabinoid CB1 receptor binding in brain areas.

    Science.gov (United States)

    Marco, Eva María; Rubino, Tiziana; Adriani, Walter; Viveros, María-Paz; Parolaro, Daniela; Laviola, Giovanni

    2009-02-27

    Despite the alarming increment in the use and abuse of cannabis preparations among young people, little is known about possible long-term consequences of targeting the endocannabinoid system during the critical developmental period of adolescence. Therefore, we aimed to analyze possible long-lasting neurobiological consequences of enhancing endocannabinoid signalling during adolescence, by means of blocking anandamide (AEA) hydrolysis. Adolescent Wistar male rats were administered an inhibitor of AEA hydrolysis, i.e. URB597 (0, 0.1 or 0.5 mg/kg/day from postnatal days 38 to 43). The expression of brain cannabinoid receptor type 1 (CB1R) was then analyzed by [(3)H]CP-55,940 auto-radiographic binding at adulthood. Repeated URB597 administration during adolescence persistently modified CB1R binding in a region-dependent manner. A long-lasting decrease of CB1R binding levels was found in caudate-putamen, nucleus accumbens, ventral tegmental area and hippocampus, while an opposite increment was observed in the locus coeruleus. Present results provide evidence for long-lasting effects of adolescent URB597 administration. Activation of endocannabinoid transmission during the still plastic phase of adolescence may have implications for the maturational end-point of the endocannabinoid system itself, which could lead to permanent alterations in neuronal brain circuits and behavioural responses. Insights into the developmental trajectories of this neuromodulatory system may help us to better understand and prevent outcomes of neonatal and adolescent cannabis exposure.

  2. Gz mediates the long-lasting desensitization of brain CB1 receptors and is essential for cross-tolerance with morphine

    Directory of Open Access Journals (Sweden)

    Rodríguez-Muñoz María

    2009-03-01

    Full Text Available Abstract Background Although the systemic administration of cannabinoids produces antinociception, their chronic use leads to analgesic tolerance as well as cross-tolerance to morphine. These effects are mediated by cannabinoids binding to peripheral, spinal and supraspinal CB1 and CB2 receptors, making it difficult to determine the relevance of each receptor type to these phenomena. However, in the brain, the CB1 receptors (CB1Rs are expressed at high levels in neurons, whereas the expression of CB2Rs is marginal. Thus, CB1Rs mediate the effects of smoked cannabis and are also implicated in emotional behaviors. We have analyzed the production of supraspinal analgesia and the development of tolerance at CB1Rs by the direct injection of a series of cannabinoids into the brain. The influence of the activation of CB1Rs on supraspinal analgesia evoked by morphine was also evaluated. Results Intracerebroventricular (icv administration of cannabinoid receptor agonists, WIN55,212-2, ACEA or methanandamide, generated a dose-dependent analgesia. Notably, a single administration of these compounds brought about profound analgesic tolerance that lasted for more than 14 days. This decrease in the effect of cannabinoid receptor agonists was not mediated by depletion of CB1Rs or the loss of regulated G proteins, but, nevertheless, it was accompanied by reduced morphine analgesia. On the other hand, acute morphine administration produced tolerance that lasted only 3 days and did not affect the CB1R. We found that both neural mu-opioid receptors (MORs and CB1Rs interact with the HINT1-RGSZ module, thereby regulating pertussis toxin-insensitive Gz proteins. In mice with reduced levels of these Gz proteins, the CB1R agonists produced no such desensitization or morphine cross-tolerance. On the other hand, experimental enhancement of Gz signaling enabled an acute icv administration of morphine to produce a long-lasting tolerance at MORs that persisted for more than

  3. Cannabinoid CB1 and CB2 receptors and fatty acid amide hydrolase are specific markers of plaque cell subtypes in human multiple sclerosis.

    Science.gov (United States)

    Benito, Cristina; Romero, Juan Pablo; Tolón, Rosa María; Clemente, Diego; Docagne, Fabián; Hillard, Cecilia J; Guaza, Camen; Romero, Julián

    2007-02-28

    Increasing evidence supports the idea of a beneficial effect of cannabinoid compounds for the treatment of multiple sclerosis (MS). However, most experimental data come from animal models of MS. We investigated the status of cannabinoid CB1 and CB2 receptors and fatty acid amide hydrolase (FAAH) enzyme in brain tissue samples obtained from MS patients. Areas of demyelination were identified and classified as active, chronic, and inactive plaques. CB1 and CB2 receptors and FAAH densities and cellular sites of expression were examined using immunohistochemistry and immunofluorescence. In MS samples, cannabinoid CB1 receptors were expressed by cortical neurons, oligodendrocytes, and also oligodendrocyte precursor cells, demonstrated using double immunofluorescence with antibodies against the CB1 receptor with antibodies against type 2 microtubule-associated protein, myelin basic protein, and the platelet-derived growth factor receptor-alpha, respectively. CB1 receptors were also present in macrophages and infiltrated T-lymphocytes. Conversely, CB2 receptors were present in T-lymphocytes, astrocytes, and perivascular and reactive microglia (major histocompatibility complex class-II positive) in MS plaques. Specifically, CB2-positive microglial cells were evenly distributed within active plaques but were located in the periphery of chronic active plaques. FAAH expression was restricted to neurons and hypertrophic astrocytes. As seen for other neuroinflammatory conditions, selective glial expression of cannabinoid CB1 and CB2 receptors and FAAH enzyme is induced in MS, thus supporting a role for the endocannabinoid system in the pathogenesis and/or evolution of this disease.

  4. Mice lacking cannabinoid CB1-, CB2-receptors or both receptors show increased susceptibility to trinitrobenzene sulfonic acid (TNBS)-induced colitis.

    Science.gov (United States)

    Engel, M A; Kellermann, C A; Burnat, G; Hahn, E G; Rau, T; Konturek, P C

    2010-02-01

    This study was performed to assess whether mice lacking the cannabinoid receptor CB1, CB2 or both receptors show increased susceptibility to TNBS colitis in comparison to wildtype mice. Previously, activation of CB1 and CB2 receptors showed attenuation of TNBS colitis in mice. The aim of the study was to investigate the susceptibility of three mouse strains CB1-, CB2- and CB1+2 double knockout mice in the model of TNBS colitis. The different knockout mice were given each a single enema with TNBS 7 mg, volume 150 microl (in 50% ethanol solution) on day 1. Control group (C57BL/6 mice) received the same concentration of TNBS enema and each strain received vehicle application of 150 microl 50% ethanol solution. After a 3-day period, the animals were sacrificed and their colon excised. A scoring system was used to describe macroscopical and histological changes. Messenger RNA-expression of TNF-alpha and IL-1beta as pro-inflammatory markers was measured by RT-PCR. All three knockout strains showed increased susceptibility to TNBS colitis quantified by macroscopical and histological scoring systems and pro-inflammatory cytokine expression in comparison to the TNBS control group (wild type C57BL/6 animals). Mice lacking the CB1-, CB2-receptor or both receptors showed aggravation of inflammation in the model of TNBS colitis. Lacking of both cannabinoid receptors did not result in potentiation of colitis severity compared to lacking of each CB1 or CB2, respectively. These results suggest that the endocannabinoid system may have tonic inhibitory effects on inflammatory responses in the colon.

  5. A new perspective on cannabinoid signalling: complementary localization of fatty acid amide hydrolase and the CB1 receptor in rat brain.

    OpenAIRE

    1998-01-01

    CB1-type cannabinoid receptors in the brain mediate effects of the drug cannabis. Anandamide and sn-2 arachidonylglycerol (2-AG) are putative endogenous ligands for CB1 receptors, but it is not known which cells in the brain produce these molecules. Recently, an enzyme which catalyses hydrolysis of anandamide and 2-AG, known as fatty acid amide hydrolase (FAAH), was identified in mammals. Here we have analysed the distribution of FAAH in rat brain and compared its cellular localization with C...

  6. Cannabinoid CB1 receptors in the dorsal hippocampus and prelimbic medial prefrontal cortex modulate anxiety-like behavior in rats: additional evidence.

    Science.gov (United States)

    Lisboa, Sabrina F; Borges, Anna A; Nejo, Priscila; Fassini, Aline; Guimarães, Francisco S; Resstel, Leonardo B

    2015-06-03

    Endocannabinoids (ECBs) such as anandamide (AEA) act by activating cannabinoid type 1 (CB1) or 2 (CB2) receptors. The anxiolytic effect of drugs that facilitate ECB effects is associated with increase in AEA levels in several encephalic areas, including the prefrontal cortex (PFC). Activation of CB1 receptors by CB1 agonists injected directly into these areas is usually anxiolytic. However, depending on the encephalic region being investigated and on the stressful experiences, opposite effects were observed, as reported in the ventral HIP. In addition, contradictory results have been reported after CB1 activation in the dorsal HIP (dHIP). Therefore, in the present paper we have attempted to verify if directly interfering with ECB metabolism/reuptake in the prelimbic (PL) portion of the medial PFC (MPFC) and dHIP would produce different effects in two conceptually distinct animal models: the elevated plus maze (EPM) and the Vogel conflict test (VCT). We observed that drugs which interfere with ECB reuptake/metabolism in both the PL and in the dentate gyrus of the dHIP induced anxiolytic-like effect, in both the EPM and in the VCT via CB1 receptors, suggesting that CB1 signaling in these brain regions modulates defensive responses to both innate and learned threatening stimuli. This data further strengthens previous results indicating modulation of hippocampal and MPFC activity via CB1 by ECBs, which could be therapeutically targeted to treat anxiety disorders.

  7. The anabolic steroid nandrolone alters cannabinoid self-administration and brain CB1 receptor density and function.

    Science.gov (United States)

    Struik, Dicky; Fadda, Paola; Zara, Tamara; Zamberletti, Erica; Rubino, Tiziana; Parolaro, Daniela; Fratta, Walter; Fattore, Liana

    2017-01-01

    Clinical and pre-clinical observations indicate that anabolic-androgenic steroids can induce neurobiological changes that alter the rewarding effects of drugs of abuse. In this study, we investigated the effect of the anabolic steroid nandrolone on the rewarding properties of the cannabinoid CB1 receptor agonist WIN55,212-2 (WIN) in rats. Lister Hooded male rats were treated intramuscularly with nandrolone (15mg/kg) or vehicle for 14 consecutive days, and then allowed to self-administer WIN (12.5μg/kg/infusion) intravenously. After reaching stable drug intake, self-administration behavior was extinguished to examine drug- and cue-induced reinstatement of cannabinoid-seeking behavior. Other behavioral parameters presumed to influence drug-taking and drug-seeking behaviors were examined to gain more insight into the behavioral specificity of nandrolone treatment. Finally, animals were sacrificed for analysis of CB1 receptor density and function in selected brain areas. We found that nandrolone-treated rats self-administered up to 2 times more cannabinoid than vehicle-treated rats, but behaved similarly to control rats when tested for drug- and cue-induced reinstatement of cannabinoid-seeking behavior. Enhanced cannabinoid intake by nandrolone-treated rats was not accompanied by changes in locomotor activity, sensorimotor gating, or memory function. However, our molecular data show that after chronic WIN self-administration nandrolone-treated rats display altered CB1 receptor density and function in selected brain areas. We hypothesize that increased cannabinoid self-administration in nandrolone-treated rats results from a nandrolone-induced decrease in reward function, which rats seem to compensate by voluntarily increasing their cannabinoid intake. Altogether, our findings corroborate the hypothesis that chronic exposure to anabolic-androgenic steroids induces dysfunction of the reward pathway in rats and might represent a potential risk factor for abuse of

  8. The gastric CB1 receptor modulates ghrelin production through the mTOR pathway to regulate food intake.

    Directory of Open Access Journals (Sweden)

    Lucia L Senin

    Full Text Available Over the years, the knowledge regarding the relevance of the cannabinoid system to the regulation of metabolism has grown steadily. A central interaction between the cannabinoid system and ghrelin has been suggested to regulate food intake. Although the stomach is the main source of ghrelin and CB1 receptor expression in the stomach has been described, little information is available regarding the possible interaction between the gastric cannabinoid and ghrelin systems in the integrated control of energy homeostasis. The main objective of the present work was to assess the functional interaction between these two systems in terms of food intake using a combination of in vivo and in vitro approaches. The present work demonstrates that the peripheral blockade of the CB1 receptor by rimonabant treatment decreased food intake but only in food-deprived animals. This anorexigenic effect is likely a consequence of decreases in gastric ghrelin secretion induced by the activation of the mTOR/S6K1 intracellular pathway in the stomach following treatment with rimonabant. In support of this supposition, animals in which the mTOR/S6K1 intracellular pathway was blocked by chronic rapamycin treatment, rimonabant had no effect on ghrelin secretion. Vagal communication may also be involved because rimonabant treatment was no longer effective when administered to animals that had undergone surgical vagotomy. In conclusion, to the best of our knowledge, the present work is the first to describe a CB1 receptor-mediated mechanism that influences gastric ghrelin secretion and food intake through the mTOR pathway.

  9. The inhibitory effect of combination treatment with leptin and cannabinoid CB1 receptor agonist on food intake and body weight gain is mediated by serotonin 1B and 2C receptors.

    Science.gov (United States)

    Wierucka-Rybak, M; Wolak, M; Juszczak, M; Drobnik, J; Bojanowska, E

    2016-06-01

    Previous studies reported that the co-injection of leptin and cannabinoid CB1 receptor antagonists reduces food intake and body weight in rats, and this effect is more profound than that induced by these compounds individually. Additionally, serotonin mediates the effects of numerous anorectic drugs. To investigate whether serotonin interacts with leptin and endocannabinoids to affect food intake and body weight, we administered 5-hydroxytryptamine(HT)1B and 5-hydroxytryptamine(HT)2C serotonin receptor antagonists (3 mg/kg GR 127935 and 0.5 mg/kg SB 242084, respectively) to male Wistar rats treated simultaneously with leptin (100 μg/kg) and the CB1 receptor inverse agonist AM 251 (1 mg/kg) for 3 days. In accordance with previous findings, the co-injection of leptin and AM 251, but not the individual injection of each drug, resulted in a significant decrease in food intake and body weight gain. Blockade of the 5-HT1B and 5-HT2C receptors completely abolished the leptin- and AM 251-induced anorectic and body-weight-reducing effects. These results suggest that serotonin mediates the leptin- and AM 251-dependent regulation of feeding behavior in rats via the 5-HT1B and 5-HT2C receptors.

  10. Anatomically heterogeneous populations of CB1 cannabinoid receptor-expressing interneurons in the CA3 region of the hippocampus show homogeneous input-output characteristics.

    Science.gov (United States)

    Szabó, Gergely G; Papp, Orsolya I; Máté, Zoltán; Szabó, Gábor; Hájos, Norbert

    2014-12-01

    A subpopulation of GABAergic cells in cortical structures expresses CB1 cannabinoid receptors (CB1 ) on their axon terminals. To understand the function of these interneurons in information processing, it is necessary to uncover how they are embedded into neuronal circuits. Therefore, the proportion of GABAergic terminals expressing CB1 and the morphological and electrophysiological properties of CB1 -immunoreactive interneurons should be revealed. We investigated the ratio and the origin of CB1 -expressing inhibitory boutons in the CA3 region of the hippocampus. Using immunocytochemical techniques, we estimated that ∼40% of GABAergic axon terminals in different layers of CA3 also expressed CB1 . To identify the inhibitory cell types expressing CB1 in this region, we recorded and intracellularly labeled interneurons in hippocampal slices. CB1 -expressing interneurons showed distinct axonal arborization, and were classified as basket cells, mossy-fiber-associated cells, dendritic-layer-innervating cells or perforant-path-associated cells. In each morphological category, a substantial variability in axonal projection was observed. In contrast to the diverse morphology, the active and passive membrane properties were found to be rather similar. Using paired recordings, we found that pyramidal cells displayed large and fast unitary postsynaptic currents in response to activating basket and mossy-fiber-associated cells, while they showed slower and smaller synaptic events in pairs originating from interneurons that innervate the dendritic layer, which may be due to dendritic filtering. In addition, CB1 activation significantly reduced the amplitude of the postsynaptic currents in each cell pair tested. Our data suggest that CB1 -expressing interneurons with different axonal projections have comparable physiological characteristics, contributing to a similar proportion of GABAergic inputs along the somato-dendritic axis of CA3 pyramidal cells.

  11. AAV-mediated overexpression of the CB1 receptor in the mPFC of adult rats alters cognitive flexibility, social behavior and emotional reactivity

    Directory of Open Access Journals (Sweden)

    Matthias eKlugmann

    2011-07-01

    Full Text Available The endocannabinoid (ECB system is strongly involved in the regulation of cognitive processing and emotional behavior and evidence indicates that ECB signaling might affect these behavioral abilities by modulations of prefrontal cortical functions. The aim of the present study was to examine the role of the CB1 receptor in the medial prefrontal cortex (mPFC on cognitive flexibility and emotional behavior. Therefore, the CB1 receptor was overexpressed by adeno-associated virus (AAV vector-mediated gene transfer specifically in the mPFC of adult Wistar rats. Animals were then tested in different anxiety-related paradigms for emotional reactivity (e.g. elevated plus maze (EPM, light/dark emergence test (EMT, social interaction and the attentional set shift task (ASST - an adaptation of the human Wisconsin card sorting test - for cognitive abilities and behavioral flexibility. A subtle increase in exploratory behavior was found in CB1 receptor overexpressing animals (CB1-R compared to empty vector injected controls (Empty in the EMT and EPM, although general locomotor activity did not differ between the groups. During social interaction testing, social contact behavior towards the unknown conspecific was found to be decreased, whereas social withdrawal was increased in CB1-R animals and they showed an inadequate increase in exploratory behavior compared to control animals. In the ASST, impaired reversal learning abilities were detected in CB1-R animals compared to controls, indicating reduced behavioral flexibility. In conclusion, upregulation of the CB1 receptor specifically in the rat mPFC induces alterations in emotional reactivity, leads to inadequate social behavior and impairs cognitive flexibility. These findings might be relevant for neuropsychiatric disorders, since higher cortical CB1 receptor expression levels as well as similar behavioral impairments as observed in the present study have been described in schizophrenic patients.

  12. Opposite regulation of cannabinoid CB1 and CB2 receptors in the prefrontal cortex of rats treated with cocaine during adolescence.

    Science.gov (United States)

    García-Cabrerizo, Rubén; García-Fuster, M Julia

    2016-02-26

    The endocannabinoid system is implicated in the neurobiology of cocaine addiction, although it is not clear how cocaine regulates brain CB1 and CB2 receptors, especially during adolescence, a critical moment for shaping adult response to drug use. This study evaluated CB1 and CB2 protein levels in prefrontal cortex (PFC) and hippocampus (HC) by western blot analysis with specific and validated antibodies: (1) basally during adolescence (post-natal day PND 40, PND 47, PND 54), (2) by a sensitizing regimen of cocaine (15mg/kg, 7 days, i.p.) during different windows of adolescence vulnerability (PND 33-39, PND 40-46, PND 47-53), and (3) following repeated cocaine administration during adolescence (PND 33-39) in adulthood (PND 64). The results demonstrated a dynamic and opposite basal modulation of CB1 and CB2 receptors in PFC and HC during adolescence. CB1 receptor levels were increased while CB2 receptors were decreased as compared to adulthood with asymptotes values around mid adolescence (PND 47) both in PFC (CB1: +45±22, pCB1: +53±23, pCB1 (+55±10%, p<0.05) and CB2 (-25±10%, p<0.05) receptors when administered during early adolescence and only in PFC. However, the changes observed in PFC by repeated cocaine administration in adolescence were transient and did not endure into adulthood. These results identified a period of vulnerability during adolescence at which cocaine dysregulated the content of CB receptors in PFC, suggesting an opposite role for these receptors in the effects mediated by cocaine.

  13. Altered CB1 receptor coupling to G-proteins in the post-mortem caudate nucleus and cerebellum of alcoholic subjects.

    Science.gov (United States)

    Erdozain, Amaia M; Rubio, Marina; Meana, J Javier; Fernández-Ruiz, Javier; Callado, Luis F

    2015-11-01

    Biochemical, pharmacological and genetic evidence suggests the involvement of the endocannabinoid system in alcohol dependence. The aim of the present study was to evaluate the state of CB1 receptors in post-mortem caudate nucleus, hippocampus and cerebellum of alcoholic subjects.CB1 protein levels were measured by Western blot, CB1 receptor density and affinity by [(3)H]WIN55,212-2 saturation assays and CB1 functionality by [(35)S]GTPγS binding assays. Experiments were performed in samples from 24 subjects classified as non-suicidal alcoholics (n = 6), suicidal alcoholics (n = 6), non-alcoholic suicide victims (n = 6) and control subjects (n = 6).Alcoholic subjects presented hyperfunctional CB1 receptors in the caudate nucleus resulting in a higher maximal effect in both alcoholic groups compared to the non-alcoholic groups (p CB1 protein expression in either region. In the hippocampus of alcoholic subjects, no changes were observed either in the functionality, density or protein levels.Our data support an association between endocannabinoid system activity and alcoholism. The modifications reported here could be either a consequence of high lifetime ethanol consumption or a vulnerability factor to develop alcohol addiction.

  14. Effects of targeted deletion of cannabinoid receptors CB1 and CB2 on immune competence and sensitivity to immune modulation by Delta9-tetrahydrocannabinol.

    Science.gov (United States)

    Springs, Alison E B; Karmaus, Peer W F; Crawford, Robert B; Kaplan, Barbara L F; Kaminski, Norbert E

    2008-12-01

    The role of cannabinoid receptors, CB1 and CB2, in immune competence and modulation by Delta9-tetrahydrocannabinol (Delta9-THC) was investigated in CB1(-/-)/CB2(-/-) mice. Immunofluorescence analysis of splenic leukocytes showed no significant differences in the percentage of T cell subsets, B cells, or macrophages between wild-type and CB1(-/-)/CB2(-/-) mice. Lymphoproliferative control responses to PHA, phorbol ester plus ionomycin, or LPS and sensitivity to suppression by Delta9-THC showed no profound differences between the two genotypes, although some differences were observed in control baseline responses. Likewise, similar control responses and sensitivity to Delta9-THC were observed in mixed lymphocyte responses (MLR) and in IL-2 and IFN-gamma production in both genotypes. Conversely, humoral immune responses showed a markedly different profile of activity. Delta9-THC suppressed the in vivo T cell-dependent, anti-sheep RBC (anti-sRBC) IgM antibody-forming cell (AFC) response in wild-type but not in CB1(-/-)/CB2(-/-) mice, and the in vitro anti-sRBC IgM response in CB1(-/-)/CB2(-/-) splenocytes was too low to rigorously assess CB1/CB2 involvement in modulation by Delta9-THC. Conversely, comparable in vitro IgM AFC control responses to LPS and CD40 ligand (CD40L) activation were observed in the two genotypes. Interestingly, LPS-induced IgM responses were refractory to suppression by Delta9-THC, regardless of genotype, and CD40L-induced IgM responses were only suppressed by Delta9-THC in wild-type but not in CB1(-/-)/CB2(-/-) B cells. Collectively, we demonstrate differential involvement of CB1 and/or CB2 in immune modulation by Delta9-THC and in some control responses. Moreover, CB1/CB2 involvement was observed in humoral responses requiring CD40-initiated signaling for suppression by Delta9-THC.

  15. The Cannabinoid Receptor CB1 Interacts with the WAVE1 Complex and Plays a Role in Actin Dynamics and Structural Plasticity in Neurons.

    Science.gov (United States)

    Njoo, Christian; Agarwal, Nitin; Lutz, Beat; Kuner, Rohini

    2015-10-01

    The molecular composition of the cannabinoid type 1 (CB1) receptor complex beyond the classical G-protein signaling components is not known. Using proteomics on mouse cortex in vivo, we pulled down proteins interacting with CB1 in neurons and show that the CB1 receptor assembles with multiple members of the WAVE1 complex and the RhoGTPase Rac1 and modulates their activity. Activation levels of CB1 receptor directly impacted on actin polymerization and stability via WAVE1 in growth cones of developing neurons, leading to their collapse, as well as in synaptic spines of mature neurons, leading to their retraction. In adult mice, CB1 receptor agonists attenuated activity-dependent remodeling of dendritic spines in spinal cord neurons in vivo and suppressed inflammatory pain by regulating the WAVE1 complex. This study reports novel signaling mechanisms for cannabinoidergic modulation of the nervous system and demonstrates a previously unreported role for the WAVE1 complex in therapeutic applications of cannabinoids.

  16. Altered dendritic distribution of dopamine D2 receptors and reduction in mitochondrial number in parvalbumin-containing interneurons in the medial prefrontal cortex of cannabinoid-1 (CB1) receptor knockout mice

    OpenAIRE

    2012-01-01

    The prelimbic prefrontal cortex (PL) is a brain region integral to complex behaviors that are highly influenced by cannabinoids and by dopamine D2 receptor (D2R)-mediated regulation of fast-firing parvalbumin-containing interneurons. We have recently shown that constitutive deletion of the cannabinoid CB1 receptor (CB1R) greatly reduces parvalbumin levels in these neurons. The effects of CB1R deletion on PL parvalbumin interneurons may be ascribed to loss of CB1R-mediated retrograde signaling...

  17. Cannabinoid receptor CB1 is involved in nicotine-induced protection against Aβ1-42 neurotoxicity in HT22 cells.

    Science.gov (United States)

    Wu, Mingchun; Jia, Ji; Lei, Chong; Ji, Ling; Chen, Xiaodan; Sang, Hanfei; Xiong, Lize

    2015-03-01

    Emerging evidences suggest that nicotine exerts a neuroprotective effect on Alzheimer's disease (AD), yet the precise mechanism is not fully elucidated. Here, HT22 cells were exposed to amyloid beta protein fragment (Aβ)1-42 to mimic the pathological process of neuron in AD. We hypothesized that cannabinoid receptor CB1 is involved in the nicotine-induced neuroprotection against Aβ1-42 injury in HT22 cells. CB1 expression in HT22 cells was investigated by immunocytochemistry and Western blot. The injury of HT22 cells was evaluated by cellular morphology, cell viability, and lactate dehydrogenase (LDH) release. The apoptosis of HT22 cells was assessed by flow cytometry and expressions of Bcl-2 and Bax. The results demonstrated that nicotine markedly upregulated CB1 expression, increased cell viability, ameliorated cellular morphology, decreased LDH release, and reduced the apoptotic rate of HT22 cells exposed to Aβ1-42 for 24 h, while the blockade of CB1 or the inhibition of protein kinase C (PKC) partially reversed the neuroprotection. Furthermore, the blockade of CB1 reversed nicotine-induced PKC activation in HT22 cells exposed to Aβ1-42. These results suggest that CB1 is involved in the nicotine-induced neuroprotection against Aβ1-42 neurotoxicity, and the neuroprotection may be dependent on the activation of PKC.

  18. CB1 Cannabinoid Receptor-Dependent and -Independent Inhibition of Depolarization-Induced Calcium Influx in Oiigodendrocytes

    Institute of Scientific and Technical Information of China (English)

    SUSANA MATO; ELENA ALBERDI; CATHERINE LEDENT; MASAHIKO WATANABE; AND CARLOS MATUTE

    2009-01-01

    Regulation of Ca2+ homeostasis plays a critical role in oligodendrocyte function and survival. Canna-binoid CB2 and CB2 receptors have been shown to regulate Ca2+ levels and/or K+ currents in a variety of cell types. In this study we investigated the effect of cannabinoid compounds on the Ca2+ influx elicited in cultured oligodendro-cytes by transient membrane depolarization with an elevated extracellular K+ concentration (50 mM). The CB2 re-ceptor agonist arachidonoyl-chloro-ethanolamide (ACEA) elicited a concentration-dependent inhibition of depolariza-tion-evoked Ca2+ transients in oligodendroglial somata with a maximal effect (94 ± 3)% and an EC50 of 1.3 ±0.03 μM. This activity was mimicked by the CB2/CB2 agonist CP55,940, as well as by the endocannabinoids N-arachidonoyl-ethanolamine (anandamide, AEA) and 2-arachidonoylglycerol (2-AG), whereas the CB2 receptor se-lective agonist JWH133 was ineffective. The CB2 receptor antagonist AM251 (1 μM) also reduced the Ca2+ response evoked by high extracellular K+ and did not prevent the inhibition elicited by ACEA (3 μM). Nevertheless, the a-bility of ACEA and AEA to reduce depolarization-evoked Ca2+ transients was significantly reduced in oligodendro-cytes from CB2 receptor knockout mice, as well as by pretreatment with pertussis toxin. Bath application of the in-wardly rectifying K+ channels (Kir channels) blockers BaCl2 (300 μM) and CsCl2 (1 mM) reduced the size of volt-age-induced Ca2+ influx and partially prevented the inhibitory effect of ACEA. Our results indicate that eannabinoids inhibit depolarization-evoked Ca2+ transients in oligodendrocytes via CB2 receptor-independent and -dependent mech-anisms that involve the activation of PTX-sensitive Gi/o proteins and the blockade of Kir channels. C 2008 Wiley-Liss, Inc.%Ca2+稳态平衡的调节在少突胶质细胞功能和存活中起重要作用.大麻素CB1和CB2受体在许多细胞中调节Ca2+水平和/或K+电流.本文利用培养的少突胶质细

  19. Deletion of G-protein-coupled receptor 55 promotes obesity by reducing physical activity

    Science.gov (United States)

    Cannabinoid receptor 1 (CB1) is the best-characterized cannabinoid receptor, and CB1 antagonists are used in clinical trials to treat obesity. Because of the wide range of CB1 functions, the side effects of CB1 antagonists pose serious concerns. G-protein-coupled receptor 55 (GPR55) is an atypical c...

  20. CB1 and CB2 cannabinoid receptor expression during development and in epileptogenic developmental pathologies

    NARCIS (Netherlands)

    Zurolo, E.; Iyer, A.M.; Spliet, W.G.M.; van Rijen, P.C.; Troost, D.; Gorter, J.A.; Aronica, E.

    2010-01-01

    Recent data support the involvement of the endocannabinoid signaling in early brain development, as well as a key role of cannabinoid receptors (CBR) in pathological conditions associated with unbalanced neuronal excitability and inflammation. Using immunocytochemistry, we explored the expression an

  1. The CB2-preferring agonist JWH015 also potently and efficaciously activates CB1 in autaptic hippocampal neurons.

    Science.gov (United States)

    Murataeva, N; Mackie, K; Straiker, A

    2012-11-01

    The G protein coupled receptors CB(1) and CB(2) are targets for the psychoactive constituents of cannabis, chief among them Δ(9)-THC. They are also key components of the multifunctional endogenous cannabinoid signaling system. CB(1) and CB(2) receptors modulate a wide variety of physiological systems including analgesia, memory, mood, reward, appetite and immunity. Identification and characterization of selective CB(1) and CB(2) receptor agonists and antagonists will facilitate understanding the precise physiological and pathophysiological roles of cannabinoid receptors in these systems. This is particularly necessary in the case of CB(2) because these receptors are sparsely expressed and problematic to detect using traditional immunocytochemical approaches. 1-Propyl-2-methyl-3-(1-naphthoyl)indole (JWH015) is an aminoalkylindole that has been employed as a "CB(2)-selective" agonist in more than 40 published papers. However, we have found that JWH015 potently and efficaciously activates CB(1) receptors in neurons. Using murine autaptic hippocampal neurons, which express CB(1), but not CB(2) receptors, we find that JWH015 inhibits excitatory postsynaptic currents with an EC50 of 216nM. JWH015 inhibition is absent in neurons from CB(1)(-/-) cultures and is reversed by the CB(1) antagonist, SR141716 [200nM]. Furthermore, JWH015 partially occludes CB(1)-mediated DSE (∼35% remaining), an action reversed by the CB(2) antagonist, AM630 [1 and 3μM], suggesting that high concentrations of AM630 also antagonize CB(1) receptors. We conclude that while JWH015 is a CB(2)-preferring agonist, it also activates CB(1) receptors at experimentally encountered concentrations. Thus, CB(1) agonism of JWH015 needs to be considered in the design and interpretation of experiments that use JWH015 to probe CB(2)-signaling.

  2. Role of pre-junctional CB1, but not CB2 , TRPV1 or GPR55 receptors in anandamide-induced inhibition of the vasodepressor sensory CGRPergic outflow in pithed rats.

    Science.gov (United States)

    Marichal-Cancino, Bruno A; Altamirano-Espinoza, Alain H; Manrique-Maldonado, Guadalupe; MaassenVanDenBrink, Antoinette; Villalón, Carlos M

    2014-03-01

    Stimulation of the perivascular sensory outflow in pithed rats produces vasodepressor responses mediated by CGRP release. Interestingly, endocannabinoids such as anandamide (which interacts with CB1 , CB2 , TRPV1 and GPR55 receptors) can regulate the activity of perivascular sensory nerves in dural blood vessels by modulating CGRP release. Yet, as no publication has reported whether this mechanism is operative in the healthy systemic vasculature, this study has specifically analysed the receptors mediating the potential inhibitory effects of the cannabinoid (CB) receptor agonists anandamide (non-selective), JWH-015 (CB2 ) and lysophosphatidylinositol (GPR55) on the rat vasodepressor sensory CGRPergic outflow (an index of systemic vasodilatation). Healthy pithed rats were pre-treated with consecutive i.v. continuous infusions of hexamethonium, methoxamine and the above agonists. Electrical spinal (T9 -T12 ) stimulation of the vasodepressor sensory CGRPergic outflow or i.v. injections of α-CGRP produced frequency-dependent or dose-dependent vasodepressor responses. The infusions of anandamide in a dose-dependent manner inhibited the vasodepressor responses by electrical stimulation (remaining unaffected by JWH-015 or lysophosphatidylinositol), but not those by α-CGRP. After i.v. administration of antagonists, the inhibition by 3.1 μg/kg min anandamide was: (i) potently blocked by 31-100 μg/kg NIDA41020 (CB1 ), (ii) unaffected by 180 μg/kg AM630 (CB2 ), 31 μg/kg cannabidiol (GPR55) or 31-100 μg/kg capsazepine (TRPV1) and (iii) slightly blocked by 310 μg/kg AM630. The above doses of antagonists were enough to block their respective receptors. These results suggest that anandamide-induced inhibition of the vasodepressor sensory CGRPergic outflow is mainly mediated by pre-junctional activation of CB1 receptors, with no pharmacological evidence for the role of CB2 , TRPV1 or GPR55 receptors.

  3. CB1 cannabinoid receptor enrichment in the ependymal region of the adult human spinal cord

    OpenAIRE

    Beatriz Paniagua-Torija; Angel Arevalo-Martin; Isidro Ferrer; Eduardo Molina-Holgado; Daniel Garcia-Ovejero

    2015-01-01

    Cannabinoids are involved in the regulation of neural stem cell biology and their receptors are expressed in the neurogenic niches of adult rodents. In the spinal cord of rats and mice, neural stem cells can be found in the ependymal region, surrounding the central canal, but there is evidence that this region is largely different in adult humans: lacks a patent canal and presents perivascular pseudorosettes, typically found in low grade ependymomas. Using Laser Capture Microdissection, Taqma...

  4. Evaluation of cannabinoid CB1 and CB2 receptors expression in mobile tongue squamous cell carcinoma: associations with clinicopathological parameters and patients' survival.

    Science.gov (United States)

    Theocharis, Stamatios; Giaginis, Constantinos; Alexandrou, Paraskevi; Rodriguez, Jose; Tasoulas, Jason; Danas, Eugene; Patsouris, Efstratios; Klijanienko, Jerzy

    2016-03-01

    Cannabinoid receptors (CB1R and CB2R) constitute essential members of the endocannabinoid system (ECS) which participates in many different functions indispensable to homeostatic regulation in several tissues, exerting also antitumorigenic effects. The present study aimed to assess the clinical significance of CB1R and CB2R protein expression in mobile tongue squamous cell carcinoma (SCC). CB1R and CB2R expression was assessed immunohistochemically on 28 mobile tongue SCC tissue samples and was analyzed in relation with clinicopathological characteristics and overall and disease-free patients' survival. CB1R, CB2R, and concomitant CB1R/CB2R expression was significantly increased in older compared to younger mobile tongue SCC patients (p = 0.0243, p = 0.0079, and p = 0.0366, respectively). Enhanced CB2R and concomitant CB1R/CB2R expression was significantly more frequently observed in female compared to male mobile tongue SCC patients (p = 0.0025 and p = 0.0016, respectively). Elevated CB2R expression was significantly more frequently observed in mobile tongue SCC patients presenting well-defined tumor shape compared to those with diffuse (p = 0.0430). Mobile tongue SCC patients presenting enhanced CB1R, CB2R, or concomitant CB1R/CB2R expression showed significantly longer overall (log-rank test, p = 0.004, p = 0.011, p = 0.018, respectively) and disease-free (log-rank test, p = 0.003, p = 0.007, p = 0.027, respectively) survival times compared to those with low expression. In multivariate analysis, CB1R was identified as an independent prognostic factor for disease-free patients' survival (Cox-regression analysis, p = 0.032). The present study provides evidence that CB1R and CB2R may play a role in the pathophysiological aspects of the mobile tongue SCC and even each molecule may constitute a potential target for the development of novel anti-cancer drugs for this type of malignancy.

  5. Negative inotropic effect of a CB2 agonist A-955840 in isolated rabbit ventricular myocytes is independent of CB1 and CB2 receptors.

    Science.gov (United States)

    Su, Zhi; Preusser, Lee; Diaz, Gilbert; Green, Jonathon; Liu, Xiaoqin; Polakowski, James; Dart, Michael; Yao, Betty; Meyer, Michael; Limberis, James T; Martin, Ruth L; Cox, Bryan F; Gintant, Gary A

    2011-11-01

    A-955840, a selective CB2 agonist, has been shown to elicit concentration-dependent decreases in cardiac contractility in the anesthetized dog (decreased maximal velocity of left ventricular pressure development [LV dP/dt max]). However, it is unknown whether this represents a direct effect or a response dependent on other factors (such as autonomic tone and neurohumoral factors) present in vivo. This study examined if A-955840 had a direct effect on contractility of isolated cardiac myocytes, and if so to determine the potential mechanisms. Contractility was assessed in vitro using percent changes in maximal shortening velocity of sarcomeres (dL/dt max) and fractional shortening of sarcomere length (FS) in rabbit left ventricular myocytes. L-type calcium current in myocytes was recorded using wholecell voltage-clamp techniques. A-955840 reduced dL/dt max and FS in a reversible and concentration-dependent manner with an IC50 of 11.4 μg/mL (based on dL/dt max) which is similar to the estimated IC50 value of 9.8 μg/mL based on the effects of A-955840 on LV dP/dt max in anesthetized dogs. A-955840 (4.1 μg/mL) reduced myocyte contractility (%FS) to a similar extent in the absence and presence of a CB2 antagonist, SR-2 (24.0 ± 3.4 vs 23.1 ± 3.0 %, n=5) or a CB1 antagonist, Rimonabant (18.8 ± 2.3 vs 19.8 ± 2.7 %, n=5). A-955840 (4.1 μg/mL) also reduced L-type calcium current of rabbit ventricular myocytes (1.05 ± 0.11 vs 0.70 ± 0.12 nA, n=5, P CB2 nor CB1 receptors, and consistent with off-target negative inotropy mediated by inhibition of the cardiac L-type calcium current.

  6. Subchronic nicotine exposure in adolescence induces long-term effects on hippocampal and striatal cannabinoid-CB1 and mu-opioid receptors in rats.

    Science.gov (United States)

    Marco, Eva M; Granstrem, Oleg; Moreno, Enrique; Llorente, Ricardo; Adriani, Walter; Laviola, Giovanni; Viveros, Maria-Paz

    2007-02-14

    There is evidence for the existence of functional interactions between nicotine and cannabinoids and opioid compounds in adult experimental animals. However, there is scarce information about these relationships in young animals. In the present study we evaluated short and long-term effects of a subchronic nicotine treatment [0.4 mg/kg daily i.p. injections from postnatal day (PND) 34 to PND 43], upon hippocampal and striatal cannabinoid-CB(1) and mu-opioid receptors in Wistar rats of both genders. Rats were sacrificed 2 h after the last nicotine injection (short-term effects, PND 43) or one month later (long-term effects, PND 75). Hippocampal and striatal cannabinoid CB(1) and mu-opioid receptors were quantified by Western blotting. The subchronic nicotine treatment induced a region-dependent long-lasting effect in cannabinoid CB(1) receptor: a significant increase in hippocampal cannabinoid CB(1) receptors and a significant decrease in striatal cannabinoid CB(1) receptors, with these effects being similar in males and females. With respect to mu-opioid receptors, subchronic nicotine induced a significant down-regulation in hippocampal and striatal mu-opioid receptors in the long-term, and within the striatum the effects were more marked in adult males than in females. The present results indicate that juvenile nicotine taking may have implications for the endocannabinoid and endogenous opioid function and for the behaviors served by those systems, this includes possible modification of the response of adults to different psychotropic drugs, i.e. cannabis and morphine/heroin when taken later in life.

  7. Arachidonic acid mediates non-capacitative calcium entry evoked by CB1-cannabinoid receptor activation in DDT1 MF-2 smooth muscle cells

    NARCIS (Netherlands)

    Demuth, D.G.; Gkoumassi, Effimia; Droge, M.J.; Dekkers, B.G.J.; Esselink, H.J.; van Ree, Rutger; Parsons, M.E.; Zaagsma, Hans; Molleman, A; Nelemans, Herman

    2005-01-01

    Cannabinoid CB1-receptor stimulation in DDT1 MF-2 smooth muscle cells induces a rise in [Ca2+](i), which is dependent on extracellular Ca2+ and modulated by thapsigargin-sensitive stores, suggesting capacitative Ca2+ entry (CCE), and by MAP kinase. Non-capacitative Ca2+ entry (NCCE) stimulated by ar

  8. Cannabinoid CB1 receptor expression in relation to visceral adipose depots, endocannabinoid levels, microvascular damage, and the presence of the Cnr1 A3813G variant in humans.

    Science.gov (United States)

    Bordicchia, Marica; Battistoni, Ilaria; Mancinelli, Lucia; Giannini, Elena; Refi, Giada; Minardi, Daniele; Muzzonigro, Giovanni; Mazzucchelli, Roberta; Montironi, Rodolfo; Piscitelli, Fabiana; Petrosino, Stefania; Dessì-Fulgheri, Paolo; Rappelli, Alessandro; Di Marzo, Vincenzo; Sarzani, Riccardo

    2010-05-01

    Dysregulation of the endocannabinoid system in the visceral adipose tissue (VAT) is associated with metabolic and cardiovascular complications of obesity. We studied perirenal VAT CB1 receptor expression in relation to anthropometry, VAT area and endocannabinoid levels, kidney microvascular damage (MVDa), and the presence of the CB1 gene A3813G variant, the frequency of which was also evaluated in a large population of obese-hypertensive (OH) patients with or without the metabolic syndrome (MetS). Perirenal VAT and kidney samples were obtained from 30 patients undergoing renal surgery. Total and perirenal VAT areas were determined by computed tomography. CB1 messenger RNA expression and endocannabinoid levels in perirenal VAT were determined by quantitative reverse transcriptase polymerase chain reaction and liquid chromatography-mass spectrometry, respectively. The MVDa was evaluated in healthy portions of kidney cortex. The A3813G alleles were identified by genotyping in these patients and in 280 nondiabetic OH patients (age endocannabinoid anandamide. A 2-fold higher CB1 expression was associated with MVDa. The OH patients with the A3813G allele had lower prevalence of MetS in both unadjusted and adjusted models. Genetics influence perirenal VAT CB1 expression and the prevalence of MetS in OH. Increased VAT is associated with increased perirenal VAT endocannabinoid tone, which in turn correlates with increased MVDa. Endocannabinoid overactivity might be involved in human visceral obesity and its renal complications.

  9. Localization of the CB1 type cannabinoid receptor in the rat basolateral amygdala: high concentrations in a subpopulation of cholecystokinin-containing interneurons.

    Science.gov (United States)

    McDonald, A J; Mascagni, F

    2001-01-01

    The neuronal localization of the CB1 cannabinoid receptor in the rat basolateral amygdala was studied using peroxidase and fluorescence immunohistochemical techniques. All nuclei of the basolateral amygdala contained a large number of lightly stained pyramidal neurons and a small number of more intensely stained non-pyramidal neurons. Most of the latter cells had medium-sized to large multipolar somata and three to four aspiny dendrites, but some exhibited smaller oval somata. The axon initial segments of some of these non-pyramidal neurons exhibited large swollen varicosities in colchicine-injected animals, suggesting that much of the CB1 receptor protein is transported down the axons of these cells. Double-labeling studies using immunofluorescence histochemistry combined with confocal laser scanning microscopy revealed that the great majority of non-pyramidal neurons with CB1 receptor immunoreactivity belonged to a cholecystokinin-containing subpopulation. Whereas none of the other subpopulations of non-pyramidal neurons (exhibiting immunoreactivity for calretinin, parvalbumin, or somatostatin) expressed high levels of CB1 receptor immunoreactivity, a small percentage of these cells exhibited low levels of immunoreactivity. The results indicate that cannabinoids may modulate the activity of pyramidal projection neurons as well as a subpopulation of cholecystokinin-containing non-pyramidal neurons in the basolateral amygdala. Previous studies indicate that most of the latter are inhibitory interneurons that utilize GABA as a neurotransmitter. The intense staining of the cholecystokinin-containing interneurons and the evidence that large amounts of CB1 receptor protein are transported down the axons of these cells suggests that, as in the hippocampus, cannabinoids may inhibit the release of GABA from the axon terminals of these neurons.

  10. 2-Arachidonoylglycerol modulates human endothelial cell/leukocyte interactions by controlling selectin expression through CB1 and CB2 receptors.

    Science.gov (United States)

    Gasperi, Valeria; Evangelista, Daniela; Chiurchiù, Valerio; Florenzano, Fulvio; Savini, Isabella; Oddi, Sergio; Avigliano, Luciana; Catani, Maria Valeria; Maccarrone, Mauro

    2014-06-01

    Accumulated evidence points to a key role for endocannabinoids in cell migration, and here we sought to characterize the role of these substances in early events that modulate communication between endothelial cells and leukocytes. We found that 2-arachidonoylglycerol (2-AG) was able to initiate and complete the leukocyte adhesion cascade, by modulating the expression of selectins. A short exposure of primary human umbilical vein endothelial cells (HUVECs) to 2-AG was sufficient to prime them towards an activated state: within 1h of treatment, endothelial cells showed time-dependent plasma membrane expression of P- and E-selectins, which both trigger the initial steps (i.e., capture and rolling) of leukocyte adhesion. The effect of 2-AG was mediated by CB1 and CB2 receptors and was long lasting, because endothelial cells incubated with 2-AG for 1h released the pro-inflammatory cytokine tumour necrosis factor-α (TNF-α) for up to 24h. Consistently, TNF-α-containing medium was able to promote leukocyte recruitment: human Jurkat T cells grown in conditioned medium derived from 2-AG-treated HUVECs showed enhanced L-selectin and P-selectin glycoprotein ligand-1 (PSGL1) expression, as well as increased efficiency of adhesion and trans-migration. In conclusion, our in vitro data indicate that 2-AG, by acting on endothelial cells, might indirectly promote leukocyte recruitment, thus representing a potential therapeutic target for treatment of diseases where impaired endothelium/leukocyte interactions take place.

  11. The endocannabinoid system and rimonabant: a new drug with a novel mechanism of action involving cannabinoid CB1 receptor antagonism--or inverse agonism--as potential obesity treatment and other therapeutic use.

    Science.gov (United States)

    Xie, S; Furjanic, M A; Ferrara, J J; McAndrew, N R; Ardino, E L; Ngondara, A; Bernstein, Y; Thomas, K J; Kim, E; Walker, J M; Nagar, S; Ward, S J; Raffa, R B

    2007-06-01

    There is considerable evidence that the endocannabinoid (endogenous cannabinoid) system plays a significant role in appetitive drive and associated behaviours. It is therefore reasonable to hypothesize that the attenuation of the activity of this system would have therapeutic benefit in treating disorders that might have a component of excess appetitive drive or over-activity of the endocannabinoid system, such as obesity, ethanol and other drug abuse, and a variety of central nervous system and other disorders. Towards this end, antagonists of cannabinoid receptors have been designed through rational drug discovery efforts. Devoid of the abuse concerns that confound and impede the use of cannabinoid receptor agonists for legitimate medical purposes, investigation of the use of cannabinoid receptor antagonists as possible pharmacotherapeutic agents is currently being actively investigated. The compound furthest along this pathway is rimonabant, a selective CB(1) (cannabinoid receptor subtype 1) antagonist, or inverse agonist, approved in the European Union and under regulatory review in the United States for the treatment of obesity. This article summarizes the basic science of the endocannabinoid system and the therapeutic potential of cannabinoid receptor antagonists, with emphasis on the treatment of obesity.

  12. Tonic endocannabinoid-mediated modulation of GABA release is independent of the CB1 content of axon terminals.

    Science.gov (United States)

    Lenkey, Nora; Kirizs, Tekla; Holderith, Noemi; Máté, Zoltán; Szabó, Gábor; Vizi, E Sylvester; Hájos, Norbert; Nusser, Zoltan

    2015-04-20

    The release of GABA from cholecystokinin-containing interneurons is modulated by type-1 cannabinoid receptors (CB1). Here we tested the hypothesis that the strength of CB1-mediated modulation of GABA release is related to the CB1 content of axon terminals. Basket cell boutons have on average 78% higher CB1 content than those of dendritic-layer-innervating (DLI) cells, a consequence of larger bouton surface and higher CB1 density. The CB1 antagonist AM251 caused a 54% increase in action potential-evoked [Ca(2+)] in boutons of basket cells, but not in DLI cells. However, the effect of AM251 did not correlate with CB1 immunoreactivity of individual boutons. Moreover, a CB1 agonist decreased [Ca(2+)] in a cell type- and CB1-content-independent manner. Replica immunogold labelling demonstrated the colocalization of CB1 with the Cav2.2 Ca(2+) channel subunit. Our data suggest that only a subpopulation of CB1s, within nanometre distances from their target Cav2.2 channels, are responsible for endocannabinoid-mediated modulation of GABA release.

  13. Inhibitory signaling by CB1 receptors in smooth muscle mediated by GRK5/β-arrestin activation of ERK1/2 and Src kinase.

    Science.gov (United States)

    Mahavadi, Sunila; Sriwai, Wimolpak; Huang, Jiean; Grider, John R; Murthy, Karnam S

    2014-03-01

    We examined whether CB1 receptors in smooth muscle conform to the signaling pattern observed with other Gi-coupled receptors that stimulate contraction via two Gβγ-dependent pathways (PLC-β3 and phosphatidylinositol 3-kinase/integrin-linked kinase). Here we show that the anticipated Gβγ-dependent signaling was abrogated. Except for inhibition of adenylyl cyclase via Gαi, signaling resulted from Gβγ-independent phosphorylation of CB1 receptors by GRK5, recruitment of β-arrestin1/2, and activation of ERK1/2 and Src kinase. Neither uncoupling of CB1 receptors from Gi by pertussis toxin (PTx) or Gi minigene nor expression of a Gβγ-scavenging peptide had any effect on ERK1/2 activity. The latter was abolished in muscle cells expressing β-arrestin1/2 siRNA. CB1 receptor internalization and both ERK1/2 and Src kinase activities were abolished in cells expressing kinase-deficient GRK5(K215R). Activation of ERK1/2 and Src kinase endowed CB1 receptors with the ability to inhibit concurrent contractile activity. We identified a consensus sequence (102KSPSKLSP109) for phosphorylation of RGS4 by ERK1/2 and showed that expression of a RGS4 mutant lacking Ser103/Ser108 blocked the ability of anandamide to inhibit acetylcholine-mediated phosphoinositide hydrolysis or enhance Gαq:RGS4 association and inactivation of Gαq. Activation of Src kinase by anandamide enhanced both myosin phosphatase RhoA-interacting protein (M-RIP):RhoA and M-RIP:MYPT1 association and inhibited Rho kinase activity, leading to increase of myosin light chain (MLC) phosphatase activity and inhibition of sustained muscle contraction. Thus, unlike other Gi-coupled receptors in smooth muscle, CB1 receptors did not engage Gβγ but signaled via GRK5/β-arrestin activation of ERK1/2 and Src kinase: ERK1/2 accelerated inactivation of Gαq by RGS4, and Src kinase enhanced MLC phosphatase activity, leading to inhibition of ACh-stimulated contraction.

  14. 3D-QSAR/CoMFA-Based Structure-Affinity/Selectivity Relationships of Aminoalkylindoles in the Cannabinoid CB1 and CB2 Receptors

    Directory of Open Access Journals (Sweden)

    Jaime Mella-Raipán

    2014-03-01

    Full Text Available A 3D-QSAR (CoMFA study was performed in an extensive series of aminoalkylindoles derivatives with affinity for the cannabinoid receptors CB1 and CB2. The aim of the present work was to obtain structure-activity relationships of the aminoalkylindole family in order to explain the affinity and selectivity of the molecules for these receptors. Major differences in both, steric and electrostatic fields were found in the CB1 and CB2 CoMFA models. The steric field accounts for the principal contribution to biological activity. These results provide a foundation for the future development of new heterocyclic compounds with high affinity and selectivity for the cannabinoid receptors with applications in several pathological conditions such as pain treatment, cancer, obesity and immune disorders, among others.

  15. 3D-QSAR/CoMFA-based structure-affinity/selectivity relationships of aminoalkylindoles in the cannabinoid CB1 and CB2 receptors.

    Science.gov (United States)

    Mella-Raipán, Jaime; Hernández-Pino, Santiago; Morales-Verdejo, César; Pessoa-Mahana, David

    2014-03-05

    A 3D-QSAR (CoMFA) study was performed in an extensive series of aminoalkylindoles derivatives with affinity for the cannabinoid receptors CB1 and CB2. The aim of the present work was to obtain structure-activity relationships of the aminoalkylindole family in order to explain the affinity and selectivity of the molecules for these receptors. Major differences in both, steric and electrostatic fields were found in the CB1 and CB2 CoMFA models. The steric field accounts for the principal contribution to biological activity. These results provide a foundation for the future development of new heterocyclic compounds with high affinity and selectivity for the cannabinoid receptors with applications in several pathological conditions such as pain treatment, cancer, obesity and immune disorders, among others.

  16. Synthetic and endogenous cannabinoids protect retinal neurons from AMPA excitotoxicity in vivo, via activation of CB1 receptors: Involvement of PI3K/Akt and MEK/ERK signaling pathways.

    Science.gov (United States)

    Kokona, Despina; Thermos, Kyriaki

    2015-07-01

    Cannabinoids have been suggested to protect retinal ganglion cells in different models of toxicity, but their effects on other retinal neurons are poorly known. We investigated the neuroprotective actions of the endocannabinoid N-arachidonoyl ethanolamine (Anandamide/AEA) and the synthetic cannabinoids R1-Methanandamide (MethAEA) and HU-210, in an in vivo retinal model of AMPA excitotoxicity, and the mechanisms involved in the neuroprotection. Sprague-Dawley rats were intravitreally injected with PBS or AMPA in the absence or presence of the cannabinoid agonists. Brain nitric oxide synthase (bNOS) and choline acetyltransferase (ChAT) immunoreactivity (IR), as well as TUNEL staining, assessed the AMPA-induced retinal amacrine cell loss and the dose-dependent neuroprotection afforded by cannabinoids. The CB1 receptor selective antagonist AM251 and the PI3K/Akt inhibitor wortmannin reversed the cannabinoid-induced neuroprotection, suggesting the involvement of CB1 receptors and the PI3K/Akt pathway in cannabinoids' actions. Experiments with the CB2 agonist JWH015 and [(3)H]CP55940 radioligand binding suggested that the CB2 receptor is not involved in the neuroprotection. AEA and HU-210 induced phosphorylation of Akt but only AEA induced phosphorylation of ERK1/2 kinases, as revealed by western blot analysis. To investigate the role of caspase-3 in the AMPA-induced cell death, the caspase-3 inhibitor Z-DEVD-FMK was co-injected with AMPA. Z-DEVD-FMK had no effect on AMPA excitotoxicity. Moreover, no difference was observed in the phosphorylation of SAPK/JNK kinases between PBS- and AMPA-treated retinas. These results suggest that endogenous and synthetic cannabinoids protect retinal amacrine neurons from AMPA excitotoxicity in vivo via a mechanism involving the CB1 receptors, and the PI3K/Akt and/or MEK/ERK1/2 signaling pathways.

  17. Activation of Both CB1 and CB2 Endocannabinoid Receptors Is Critical for Masculinization of the Developing Medial Amygdala and Juvenile Social Play Behavior

    Science.gov (United States)

    Falvo, David J; Whitaker, Allison R

    2017-01-01

    Abstract Juvenile social play behavior is a shared trait across a wide variety of mammalian species. When play is characterized by the frequency or duration of physical contact, males usually display more play relative to females. The endocannabinoid system contributes to the development of the sex difference in social play behavior in rats. Treating newborn pups with a nonspecific endocannabinoid agonist, WIN55,212-2, masculinizes subsequent juvenile rough-and-tumble play behavior by females. Here we use specific drugs to target signaling through either the CB1 or CB2 endocannabinoid receptor (CB1R or CB2R) to determine which modulates the development of sex differences in play. Our data reveal that signaling through both CB1R and CB2R must be altered neonatally to modify development of neural circuitry regulating sex differences in play. Neonatal co-agonism of CB1R and CB2R masculinized play by females, whereas co-antagonism of these receptors feminized rates of male play. Because of a known role for the medial amygdala in the sexual differentiation of play, we reconstructed Golgi-impregnated neurons in the juvenile medial amygdala and used factor analysis to identify morphological parameters that were sexually differentiated and responsive to dual agonism of CB1R and CB2R during the early postnatal period. Our results suggest that sex differences in the medial amygdala are modulated by the endocannabinoid system during early development. Sex differences in play behavior are loosely correlated with differences in neuronal morphology. PMID:28144625

  18. Synthesis and biological evaluation of indole-2-carboxamides bearing photoactivatable functionalities as novel allosteric modulators for the cannabinoid CB1 receptor.

    Science.gov (United States)

    Qiao, Chang-Jiang; Ali, Hamed I; Ahn, Kwang H; Kolluru, Srikanth; Kendall, Debra A; Lu, Dai

    2016-10-04

    5-Chloro-3-ethyl-N-(4-(piperidin-1-yl)phenethyl)-1H-indole-2-carboxamide (ORG27569, 1) is a prototypical allosteric modulator for the cannabinoid CB1 receptor. Based on this indole-2-carboxamide scaffold, we designed and synthesized novel CB1 allosteric modulators that possess photoactivatable functionalities, which include benzophenone, phenyl azide, aliphatic azide and phenyltrifluoromethyldiazrine. To assess their allosteric effects, the dissociation constant (KB) and allosteric binding cooperativity factor (α) were determined and compared to their parent compounds. Within this series, benzophenone-containing compounds 26 and 27, phenylazide-containing compound 28, and the aliphatic azide containing compound 36b showed allosteric binding parameters (KB and α) comparable to their parent compound 1, 7, 8, and 9, respectively. We further assessed these modulators for their impact on G-protein coupling activity. Interestingly, these compounds exhibited negative allosteric modulator properties in a manner similar to their parent compounds, which antagonize agonist-induced G-protein coupling. These novel CB1 allosteric modulators, possessing photoactivatable functionalities, provide valuable tools for future photo-affinity labeling and mapping the CB1 allosteric binding site(s).

  19. Genetic rescue of CB1 receptors on medium spiny neurons prevents loss of excitatory striatal synapses but not motor impairment in HD mice.

    Science.gov (United States)

    Naydenov, Alipi V; Sepers, Marja D; Swinney, Katie; Raymond, Lynn A; Palmiter, Richard D; Stella, Nephi

    2014-11-01

    Huntington's disease (HD) is caused by an expanded polyglutamine repeat in huntingtin protein that disrupts synaptic function in specific neuronal populations and results in characteristic motor, cognitive and affective deficits. Histopathological hallmarks observed in both HD patients and genetic mouse models include the reduced expression of synaptic proteins, reduced medium spiny neuron (MSN) dendritic spine density and decreased frequency of spontaneous excitatory post-synaptic currents (sEPSCs). Early down-regulation of cannabinoid CB1 receptor expression on MSN (CB1(MSN)) is thought to participate in HD pathogenesis. Here we present a cell-specific genetic rescue of CB1(MSN) in R6/2 mice and report that treatment prevents the reduction of excitatory synaptic markers in the striatum (synaptophysin, vGLUT1 and vGLUT2), of dendritic spine density on MSNs and of MSN sEPSCs, but does not prevent motor impairment. We conclude that loss of excitatory striatal synapses in HD mice is controlled by CB1(MSN) and can be uncoupled from the motor phenotype.

  20. Comparison of Cannabinoid CB1 Receptor Binding in Adolescent and Adult Rats: A Positron Emission Tomography Study Using [18F]MK-9470

    Directory of Open Access Journals (Sweden)

    Mathieu Verdurand

    2011-01-01

    Full Text Available Despite the important role of cannabinoid CB1 receptors (CB1R in brain development, little is known about their status during adolescence, a critical period for both the development of psychosis and for initiation to substance abuse. In the present study, we assessed the ontogeny of CB1R in adolescent and adult rats in vivo using positron emission tomography with [18F]MK-9470. Analysis of covariance (ANCOVA to control for body weight that would potentially influence [18F]MK-9470 values between the two groups revealed a main effect of age (F(1,109=5.0, P=0.02 on [18F]MK-9470 absolute binding (calculated as percentage of injected dose with adult estimated marginal means being higher compared to adolescents amongst 11 brain regions. This finding was confirmed using in vitro autoradiography with [3H]CP55,940 (F(10,99=140.1, P<0.0001. This ontogenetic pattern, suggesting increase of CB1R during the transition from adolescence to adulthood, is the opposite of most other neuroreceptor systems undergoing pruning during this period.

  1. Benzophenanthridine alkaloid, piperonyl butoxide and (S)-methoprene action at the cannabinoid-1 receptor (CB1-receptor) pathway of mouse brain: Interference with [(3)H]CP55940 and [(3)H]SR141716A binding and modification of WIN55212-2-dependent inhibition of synaptosomal l-glutamate release.

    Science.gov (United States)

    Dhopeshwarkar, Amey Sadashiv; Nicholson, Russell Alfred

    2014-01-15

    Benzophenanthridine alkaloids (chelerythrine and sanguinarine) inhibited binding of [(3)H]SR141716A to mouse brain membranes (IC50s: CB1 receptors versus spleen CB2 receptors. All compounds reduced Bmax of [(3)H]SR141716A binding to CB1 receptors, but only methoprene and piperonyl butoxide increased Kd (3-5-fold). Benzophenanthridines increased the Kd of [(3)H]CP55940 binding (6-fold), but did not alter Bmax. (S)-methoprene increased the Kd of [(3)H]CP55940 binding (by almost 4-fold) and reduced Bmax by 60%. Piperonyl butoxide lowered the Bmax of [(3)H]CP55940 binding by 50%, but did not influence Kd. All compounds reduced [(3)H]SR141716A and [(3)H]CP55940 association with CB1 receptors. Combined with a saturating concentration of SR141716A, only piperonyl butoxide and (S)-methoprene increased dissociation of [(3)H]SR141716A above that of SR141716A alone. Only piperonyl butoxide increased dissociation of [(3)H]CP55940 to a level greater than CP55940 alone. Binding results indicate predominantly allosteric components to the study compounds action. 4-Aminopyridine-(4-AP-) evoked release of l-glutamate from synaptosomes was partially inhibited by WIN55212-2, an effect completely neutralized by AM251, (S)-methoprene and piperonyl butoxide. With WIN55212-2 present, benzophenanthridines enhanced 4-AP-evoked l-glutamate release above 4-AP alone. Modulatory patterns of l-glutamate release (with WIN-55212-2 present) align with previous antagonist/inverse agonist profiling based on [(35)S]GTPγS binding. Although these compounds exhibit lower potencies compared to many classical CB1 receptor inhibitors, they may have potential to modify CB1-receptor-dependent behavioral/physiological outcomes in the whole animal.

  2. Mutation of putative GRK phosphorylation sites in the cannabinoid receptor 1 (CB1R) confers resistance to cannabinoid tolerance and hypersensitivity to cannabinoids in mice.

    Science.gov (United States)

    Morgan, Daniel J; Davis, Brian J; Kearn, Chris S; Marcus, David; Cook, Alex J; Wager-Miller, Jim; Straiker, Alex; Myoga, Michael H; Karduck, Jeffrey; Leishman, Emma; Sim-Selley, Laura J; Czyzyk, Traci A; Bradshaw, Heather B; Selley, Dana E; Mackie, Ken

    2014-04-09

    For many G-protein-coupled receptors (GPCRs), including cannabinoid receptor 1 (CB1R), desensitization has been proposed as a principal mechanism driving initial tolerance to agonists. GPCR desensitization typically requires phosphorylation by a G-protein-coupled receptor kinase (GRK) and interaction of the phosphorylated receptor with an arrestin. In simple model systems, CB1R is desensitized by GRK phosphorylation at two serine residues (S426 and S430). However, the role of these serine residues in tolerance and dependence for cannabinoids in vivo was unclear. Therefore, we generated mice where S426 and S430 were mutated to nonphosphorylatable alanines (S426A/S430A). S426A/S430A mutant mice were more sensitive to acutely administered delta-9-tetrahydrocannabinol (Δ(9)-THC), have delayed tolerance to Δ(9)-THC, and showed increased dependence for Δ(9)-THC. S426A/S430A mutants also showed increased responses to elevated levels of endogenous cannabinoids. CB1R desensitization in the periaqueductal gray and spinal cord following 7 d of treatment with Δ(9)-THC was absent in S426A/S430A mutants. Δ(9)-THC-induced downregulation of CB1R in the spinal cord was also absent in S426A/S430A mutants. Cultured autaptic hippocampal neurons from S426A/S430A mice showed enhanced endocannabinoid-mediated depolarization-induced suppression of excitation (DSE) and reduced agonist-mediated desensitization of DSE. These results indicate that S426 and S430 play major roles in the acute response to, tolerance to, and dependence on cannabinoids. Additionally, S426A/S430A mice are a novel model for studying pathophysiological processes thought to involve excessive endocannabinoid signaling such as drug addiction and metabolic disease. These mice also validate the approach of mutating GRK phosphorylation sites involved in desensitization as a general means to confer exaggerated signaling to GPCRs in vivo.

  3. Preparation of iodine-123 labeled AM251: a potential SPECT radioligand for the brain cannabinoid CB1 receptor

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    Lan, Ruoxi; Makriyannis, Alexandros [Connecticut Univ., Molecular and Cell Biology Dept., Storrs, CT (United States); Gatley, S.J. [Brookhaven National Lab., Medical Dept., Upton, NY (United States)

    1996-10-01

    We report the synthesis and labeling with iodine-123 of N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2, 4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251). This compound is an analog of the recently described cannabinoid receptor antagonist, SR141716A, in which a 4-chlorophenyl group is replaced by 4-iodophenyl. Labeling in good yield (62%) and radiochemical purity (> 95%), and high specific activity (> 2500 Ci/mmol) was achieved by an iododestannylation reaction using the tributyltin precursor, no carrier added I-123 iodide, and chloramine-T. (author).

  4. The Ratio of 2-AG to Its Isomer 1-AG as an Intrinsic Fine Tuning Mechanism of CB1 Receptor Activation

    Science.gov (United States)

    Dócs, Klaudia; Mészár, Zoltán; Gonda, Sándor; Kiss-Szikszai, Attila; Holló, Krisztina; Antal, Miklós; Hegyi, Zoltán

    2017-01-01

    Endocannabinoids are pleiotropic lipid messengers that play pro-homeostatic role in cellular physiology by strongly influencing intracellular Ca2+ concentration through the activation of cannabinoid receptors. One of the best-known endocannabinoid ‘2-AG’ is chemically unstable in aqueous solutions, thus its molecular rearrangement, resulting in the formation of 1-AG, may influence 2-AG-mediated signaling depending on the relative concentration and potency of the two isomers. To predict whether this molecular rearrangement may be relevant in physiological processes and in experiments with 2-AG, here we studied if isomerization of 2-AG has an impact on 2-AG-induced, CB1-mediated Ca2+ signaling in vitro. We found that the isomerization-dependent drop in effective 2-AG concentration caused only a weak diminution of Ca2+ signaling in CB1 transfected COS7 cells. We also found that 1-AG induces Ca2+ transients through the activation of CB1, but its working concentration is threefold higher than that of 2-AG. Decreasing the concentration of 2-AG in parallel to the prevention of 1-AG formation by rapid preparation of 2-AG solutions, caused a significant diminution of Ca2+ signals. However, various mixtures of the two isomers in a fix total concentration – mimicking the process of isomerization over time – attenuated the drop in 2-AG potency, resulting in a minor decrease in CB1 mediated Ca2+ transients. Our results indicate that release of 2-AG into aqueous medium is accompanied by its isomerization, resulting in a drop of 2-AG concentration and simultaneous formation of the similarly bioactive isomer 1-AG. Thus, the relative concentration of the two isomers with different potency and efficacy may influence CB1 activation and the consequent biological responses. In addition, our results suggest that 1-AG may play role in stabilizing the strength of cannabinoid signal in case of prolonged 2-AG dependent cannabinoid mechanisms. PMID:28265242

  5. Effects of CP 55,940 — agonist of CB1 cannabinoid receptors on ghrelin and somatostatin producing cells in the rat pancreas

    Directory of Open Access Journals (Sweden)

    Alicja Lewandowska

    2012-04-01

    Full Text Available Cannabinoids participate in the modulation of numerous functions in the human organism, increasing the sense of hunger, affecting carbohydrate and lipid metabolism, and controlling systemic energy balance mechanisms. Moreover, they influence the endocrine system functions, acting via two types of receptors, CB1 and CB2. The aim of the present study was to examine the number, distribution and activity of ghrelin and somatostatin producing endocrine cells in the pancreas of rats after a single administration of selective CP 55,940 agonist of CB1 receptor. The study was performed on 20 rats. Neuroendocrine cells were identified by immunohistochemical reactions, involving specific antibodies against ghrelin and somatostatin. The distribution and number of ghrelin- and somatostatin-immunoreactive cells were separately studied in five pancreas islets of each section. A performed analysis showed a decreased number of somatostatin-immunoreactive cells and a weak immunoreactivity of ghrelin and somatostatin containing neuroendocrine cells in the pancreatic islets of experimental rats, compared to control animals. The obtained results suggest that a single administration of a selective CP 55,940 agonist of CB1 receptor influences the immunoreactivity of endocrine cells with ghrelin and somatostatin expression in the pancreas islets.

  6. Evaluation of selective cannabinoid CB(1) and CB(2) receptor agonists in a mouse model of lipopolysaccharide-induced interstitial cystitis.

    Science.gov (United States)

    Tambaro, Simone; Casu, Maria Antonietta; Mastinu, Andrea; Lazzari, Paolo

    2014-04-15

    Interstitial cystitis is a debilitating bladder inflammation disorder. To date, the understanding of the causes of interstitial cystitis remains largely fragmentary and there is no effective treatment available. Recent experimental results have shown a functional role of the endocannabinoid system in urinary bladder. In this study, we evaluated the anti-inflammatory effect of selective cannabinoid CB1 and CB2 receptor agonists in a mouse model of interstitial cystitis. Bladder inflammation was induced in mice by lipopolysaccharide (LPS) and whole bladders were removed 24h later. LPS induced a significant increase of the contractile amplitude in spontaneous activity and a hypersensitivity to exogenous acetylcholine-induced contraction of whole-isolated bladder. Next, we evaluated the anti-inflammatory activity of cannabinoidergic compounds by pretreating mice with CB1 or CB2 selective agonist compounds, respectively ACEA and JWH015. Interestingly, JWH015, but not ACEA, antagonized LPS-induced bladder inflammation. Additionally, anti-inflammatory activity was studied by evaluation, leukocytes mucosa infiltration, myeloperoxidase activity, and mRNA expression of pro-inflammatory interleukin (IL-1α and IL-1β), tumor necrosis factor-alpha (TNF-α) and cannabinoid CB1 and CB2 receptors. JWH015 significantly decreased leukocytes infiltration in both submucosa and mucosa, as well as the myeloperoxydase activity, in LPS treated mice. JWH015 reduced mRNA expression of IL-1α, IL-1β, and TNF-α. LPS treatment increased expression of bladder CB2 but not CB1 mRNA. Taken together, these findings strongly suggest that modulation of the cannabinoid CB2 receptors might be a promising therapeutic strategy for the treatment of bladder diseases and conditions characterized by inflammation, such as interstitial cystitis.

  7. ACEA (a highly selective cannabinoid CB1 receptor agonist) stimulates hippocampal neurogenesis in mice treated with antiepileptic drugs.

    Science.gov (United States)

    Andres-Mach, Marta; Haratym-Maj, Agnieszka; Zagaja, Miroslaw; Rola, Radoslaw; Maj, Maciej; Chrościńska-Krawczyk, Magdalena; Luszczki, Jarogniew J

    2015-10-22

    Hippocampal neurogenesis plays a very important role in learning and memory functions. In a search for best neurological drugs that protect neuronal cells and stimulate neurogenesis with no side effects, cannabinoids proved to be a strong group of substances having many beneficial properties. The aim of this study was to evaluate the impact of ACEA (arachidonyl-2'-chloroethylamide--a highly selective cannabinoid CB1 receptor agonist) combined with a classical antiepileptic drug sodium valproate (VPA) on neural precursor cells' proliferation and differentiation in the mouse brain. All experiments were performed on adolescent CB57/BL male mice injected i.p. with VPA (10mg/kg), ACEA (10mg/kg) and PMSF (30 mg/kg) (phenylmethylsulfonyl fluoride--a substance protecting ACEA against degradation by the fatty-acid amidohydrolase) for 10 days. Next an acute response of proliferating neural precursor cells to ACEA and VPA administration was evaluated with Ki-67 staining (Time point 1). Next, in order to determine whether acute changes translated into long-term alterations in neurogenesis, proliferating cells were labeled with 5-bromo-2deoxyuridine (BrdU) followed by confocal microscopy used to determine the percentage of BrdU-labeled cells that showed mature cell phenotypes (Time point 2). Results indicate that ACEA with PMSF significantly increase the total number of Ki-67-positive cells when compared to the control group. Moreover, ACEA in combination with VPA increased the number of Ki-67-positive cells, whereas VPA administered alone had no impact on proliferating cells' population. Accordingly, neurogenesis study results indicate that the combination of ACEA+PMSF administered alone and in combination with VPA considerably increases the total number of BrdU-positive cells in comparison to the control group while ACEA+PMSF alone and in combination with VPA increased total numbers of BrdU-positive cells, newly born neurons and astrocytes as compared to VPA group but not to

  8. (4-(Bis(4-fluorophenyl)methyl)piperazin-1-yl)(cyclohexyl)methanone hydrochloride (LDK1229): a new cannabinoid CB1 receptor inverse agonist from the class of benzhydryl piperazine analogs.

    Science.gov (United States)

    Mahmoud, Mariam M; Olszewska, Teresa; Liu, Hui; Shore, Derek M; Hurst, Dow P; Reggio, Patricia H; Lu, Dai; Kendall, Debra A

    2015-02-01

    Some inverse agonists of cannabinoid receptor type 1 (CB1) have been demonstrated to be anorectic antiobesity drug candidates. However, the first generation of CB1 inverse agonists, represented by rimonabant (SR141716A), otenabant, and taranabant, are centrally active, with a high level of psychiatric side effects. Hence, the discovery of CB1 inverse agonists with a chemical scaffold distinct from these holds promise for developing peripherally active CB1 inverse agonists with fewer side effects. We generated a new CB1 inverse agonist, (4-(bis(4-fluorophenyl)methyl)piperazin-1-yl)(cyclohexyl)methanone hydrochloride (LDK1229), from the class of benzhydryl piperazine analogs. This compound binds to CB1 more selectively than cannabinoid receptor type 2, with a Ki value of 220 nM. Comparable CB1 binding was also observed by analogs 1-[bis(4-fluorophenyl)methyl]-4-cinnamylpiperazine dihydrochloride (LDK1203) and 1-[bis(4-fluorophenyl)methyl]-4-tosylpiperazine hydrochloride (LDK1222), which differed by the substitution on the piperazine ring where the piperazine of LDK1203 and LDK1222 are substituted by an alkyl group and a tosyl group, respectively. LDK1229 exhibits efficacy comparable with SR141716A in antagonizing the basal G protein coupling activity of CB1, as indicated by a reduction in guanosine 5'-O-(3-thio)triphosphate binding. Consistent with inverse agonist behavior, increased cell surface localization of CB1 upon treatment with LDK1229 was also observed. Although docking and mutational analysis showed that LDK1229 forms similar interactions with the receptor as SR141716A does, the benzhydryl piperazine scaffold is structurally distinct from the first-generation CB1 inverse agonists. It offers new opportunities for developing novel CB1 inverse agonists through the optimization of molecular properties, such as the polar surface area and hydrophilicity, to reduce the central activity observed with SR141716A.

  9. Novel insights into CB1 cannabinoid receptor signaling: a key interaction identified between the extracellular-3 loop and transmembrane helix 2.

    Science.gov (United States)

    Marcu, Jahan; Shore, Derek M; Kapur, Ankur; Trznadel, Megan; Makriyannis, Alexandros; Reggio, Patricia H; Abood, Mary E

    2013-05-01

    Activation of the cannabinoid CB1 receptor (CB1) is modulated by aspartate residue D2.63(176) in transmembrane helix (TMH) 2. Interestingly, D2.63 does not affect the affinity for ligand binding at the CB1 receptor. Studies in class A G protein-coupled receptors have suggested an ionic interaction between residues of TMH2 and 7. In this report, modeling studies identified residue K373 in the extracellular-3 (EC-3) loop in charged interactions with D2.63. We investigated this possibility by performing reciprocal mutations and biochemical studies. D2.63(176)A, K373A, D2.63(176)A-K373A, and the reciprocal mutant with the interacting residues juxtaposed D2.63(176)K-K373D were characterized using radioligand binding and guanosine 5'-3-O-(thio)triphosphate functional assays. None of the mutations resulted in a significant change in the binding affinity of N-(piperidiny-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichloro-phenyl)-4-methyl-1H-pyrazole-3-carboxamide hydrochloride (SR141716A) or (-)-3cis -[2-hydroxyl-4-(1,1-dimethyl-heptyl)phenyl]-trans-4-[3-hydroxyl-propyl] cyclohexan-1-ol (CP55,940). Modeling studies indicated that binding-site interactions and energies of interaction for CP55,940 were similar between wild-type and mutant receptors. However, the signaling of CP55,940, and (R)-(+)-[2,3-dihydro-5-methyl-3-[(4-morpholinyl)methyl]-pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl](1-naphthalenyl)-methanone mesylate (WIN55,212-2) was impaired at the D2.63(176)A-K373A and the single-alanine mutants. In contrast, the reciprocal D2.63(176)K-K373D mutant regained function for both CP55,940 and WIN55,212-2. Computational results indicate that the D2.63(176)-K373 ionic interaction strongly influences the conformation(s) of the EC-3 loop, providing a structure-based rationale for the importance of the EC-3 loop to signal transduction in CB1. The putative ionic interaction results in the EC-3 loop pulling over the top (extracellular side) of the receptor; this EC-3 loop conformation may serve

  10. THC (Δ9-Tetrahydrocannabinol) Exerts Neuroprotective Effect in Glutamate-affected Murine Primary Mesencephalic Cultures Through Restoring Mitochondrial Membrane Potential and Anti-apoptosis Involving CB1 Receptor-dependent Mechanism.

    Science.gov (United States)

    Nguyen, Chi Huu; Krewenka, Christopher; Radad, Khaled; Kranner, Barbara; Huber, Alexandra; Duvigneau, Johanna Catharina; Miller, Ingrid; Moldzio, Rudolf

    2016-12-01

    Aging-related neurodegenerative diseases, such as Parkinson's disease (PD) or related disorders, are an increasing societal and economic burden worldwide. Δ9-Tetrahydrocannabinol (THC) is discussed as a neuroprotective agent in several in vitro and in vivo models of brain injury. However, the mechanisms by which THC exhibits neuroprotective properties are not completely understood. In the present study, we investigated neuroprotective mechanisms of THC in glutamate-induced neurotoxicity in primary murine mesencephalic cultures, as a culture model for PD. Glutamate was administered for 48 h with or without concomitant THC treatment. Immunocytochemistry staining and resazurin assay were used to evaluate cell viability. Furthermore, superoxide levels, caspase-3 activity, and mitochondrial membrane potential were determined to explore the mode of action of this compound. THC protected dopaminergic neurons and other cell types of primary dissociated cultures from glutamate-induced neurotoxicity. Moreover, THC significantly counteracted the glutamate-induced mitochondrial membrane depolarization and apoptosis. SR141716A, a CB1 receptor antagonist, concentration-dependently blocked the protective effect of THC in primary mesencephalic cultures. In conclusion, THC exerts anti-apoptotic and restores mitochondrial membrane potential via a mechanism dependent on CB1 receptor. It strengthens the fact that THC has a benefit on degenerative cellular processes occurring, among others, in PD and other neurodegenerative diseases by slowing down the progression of neuronal cell death. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Altered dendritic distribution of dopamine D2 receptors and reduction in mitochondrial number in parvalbumin-containing interneurons in the medial prefrontal cortex of cannabinoid-1 (CB1) receptor knockout mice.

    Science.gov (United States)

    Fitzgerald, Megan L; Chan, June; Mackie, Kenneth; Lupica, Carl R; Pickel, Virginia M

    2012-12-01

    The prelimbic prefrontal cortex (PL) is a brain region integral to complex behaviors that are highly influenced by cannabinoids and by dopamine D2 receptor (D2R)-mediated regulation of fast-firing parvalbumin-containing interneurons. We have recently shown that constitutive deletion of the cannabinoid-1 receptor (CB1R) greatly reduces parvalbumin levels in these neurons. The effects of CB1R deletion on PL parvalbumin interneurons may be ascribed to loss of CB1R-mediated retrograde signaling on mesocortical dopamine transmission, and, in turn, altered expression and/or subcellular distribution of D2R in the PL. Furthermore, diminished parvalbumin expression could indicate metabolic changes in fast-firing interneurons that may be reflected in changes in mitochondrial density in this population. We therefore comparatively examined electron microscopic dual labeling of D2R and parvalbumin in CB1 (-/-) and CB1 (+/+) mice to test the hypothesis that absence of CB1R produces changes in D2R localization and mitochondrial distribution in parvalbumin-containing interneurons of the PL. CB1 (-/-) mice had a significantly lower density of cytoplasmic D2R-immunogold particles in medium parvalbumin-labeled dendrites and a concomitant increase in the density of these particles in small dendrites. These dendrites received both excitatory and inhibitory-type synapses from unlabeled terminals and contained many mitochondria, whose numbers were significantly reduced in CB1 (-/-) mice. Non-parvalbumin dendrites showed no between-group differences in either D2R distribution or mitochondrial number. These results suggest that cannabinoid signaling provides an important determinant of dendritic D2 receptor distribution and mitochondrial availability in fast-spiking interneurons.

  12. Identification of CB1/CB2 ligands from Zanthoxylum bungeanum.

    Science.gov (United States)

    Dossou, Katina S S; Devkota, Krishna P; Morton, Cynthia; Egan, Josephine M; Lu, Guanghua; Beutler, John A; Moaddel, Ruin

    2013-11-22

    In order to study cannabinoid receptor ligands, a novel plate-based assay was developed previously to measure internalization of CB1/CB2 receptors by determining the change in the intracellular levels of the radiolabeled agonists. This plate-based assay was also used for screening against complex matrices, specifically, in the present study screening for CB1/CB2 receptor activity of extracts for several species of the plant genus Zanthoxylum. The objective of this screen was to identify novel antagonists of the CB1 receptor, which simultaneously displayed agonist activity against the CB2 receptor, since compounds matching this criterion could be potential candidates for the treatment of type-1 diabetes. As a result, two Z. bungeanum extracts were deemed active, leading to the identification of eight compounds, of which compound 7 [(2E,4E,8E,10E,12E)-N-isobutyl-2,4,8,10,12-tetradecapentaenamide, γ-sanshool] was obtained as a promising lead compound.

  13. The CB1 cannabinoid receptor agonist reduces L-DOPA-induced motor fluctuation and ERK1/2 phosphorylation in 6-OHDA-lesioned rats.

    Science.gov (United States)

    Song, Lu; Yang, Xinxin; Ma, Yaping; Wu, Na; Liu, Zhenguo

    2014-01-01

    The dopamine precursor L-3,4-dihydroxyphenylalanine (L-DOPA) has been used as an effective drug for treating dopamine depletion-induced Parkinson's disease (PD). However, long-term administration of L-DOPA produces motor complications. L-DOPA has also been found to modify the two key signaling cascades, protein kinase A/dopamine- and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32) and extracellular signal-regulated kinases 1 and 2 (ERK1/2), in striatal neurons, which are thought to play a pivotal role in forming motor complications. In the present study, we tested the possible effect of a CB1 cannabinoid receptor agonist on L-DOPA-stimulated abnormal behavioral and signaling responses in vivo. Intermittent L-DOPA administration for 3 weeks induced motor fluctuation in a rat model of PD induced by intrastriatal infusion of dopamine-depleting neurotoxin 6-hydroxydopamine (6-OHDA). A single injection of a CB1 cannabinoid receptor agonist WIN-55,212-2 had no effect on L-DOPA-induced motor fluctuation. However, chronic injections of WIN-55,212-2 significantly attenuated abnormal behavioral responses to L-DOPA in 6-OHDA-lesioned rats. Similarly, chronic injections of WIN-55,212-2 influence the L-DOPA-induced alteration of DARPP-32 and ERK1/2 phosphorylation status in striatal neurons. These data provide evidence for the active involvement of CB1 cannabinoid receptors in the regulation of L-DOPA action during PD therapy.

  14. CB1 Knockout Mice Unveil Sustained CB2-Mediated Antiallodynic Effects of the Mixed CB1/CB2 Agonist CP55,940 in a Mouse Model of Paclitaxel-Induced Neuropathic Pain.

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    Deng, Liting; Cornett, Benjamin L; Mackie, Ken; Hohmann, Andrea G

    2015-07-01

    Cannabinoids suppress neuropathic pain through activation of cannabinoid CB1 and/or CB2 receptors; however, unwanted CB1-mediated cannabimimetic effects limit clinical use. We asked whether CP55,940 [(-)-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-4-(3-hydroxypropyl)cyclohexanol], a potent cannabinoid that binds with similar affinity to CB1 and CB2 in vitro, produces functionally separable CB1- and CB2-mediated pharmacological effects in vivo. We evaluated antiallodynic effects, possible tolerance, and cannabimimetic effects (e.g., hypothermia, catalepsy, CB1-dependent withdrawal signs) after systemic CP55,940 treatment in a mouse model of toxic neuropathy produced by a chemotherapeutic agent, paclitaxel. The contribution of CB1 and CB2 receptors to in vivo actions of CP55,940 was evaluated using CB1 knockout (KO), CB2KO, and wild-type (WT) mice. Low-dose CP55,940 (0.3 mg/kg daily, i.p. ) suppressed paclitaxel-induced allodynia in WT and CB2KO mice, but not CB1KO mice. Low-dose CP55,940 also produced hypothermia and rimonabant-precipitated withdrawal in WT, but not CB1KO, mice. In WT mice, tolerance developed to CB1-mediated hypothermic effects of CP55,940 earlier than to antiallodynic effects. High-dose CP55,940 (10 mg/kg daily, i.p.) produced catalepsy in WT mice, which precluded determination of antiallodynic efficacy but produced sustained CB2-mediated suppression of paclitaxel-induced allodynia in CB1KO mice; these antiallodynic effects were blocked by the CB2 antagonist 6-iodopravadoline (AM630). High-dose CP55,940 did not produce hypothermia or rimonabant-precipitated withdrawal in CB1KO mice. Our results using the mixed CB1/CB2 agonist CP55,940 document that CB1 and CB2 receptor activations produce mechanistically distinct suppression of neuropathic pain. Our study highlights the therapeutic potential of targeting cannabinoid CB2 receptors to bypass unwanted central effects associated with CB1 receptor activation.

  15. Early maternal deprivation induces gender-dependent changes on the expression of hippocampal CB(1) and CB(2) cannabinoid receptors of neonatal rats.

    Science.gov (United States)

    Suárez, Juan; Llorente, Ricardo; Romero-Zerbo, Silvana Y; Mateos, Beatriz; Bermúdez-Silva, Francisco J; de Fonseca, Fernando Rodríguez; Viveros, María-Paz

    2009-07-01

    Early maternal deprivation (MD) in rats (24 h, postnatal day 9-10) is a model for neurodevelopmental stress. There are some data proving that MD affects the endocannabinoid system (ECS) in a gender-dependent manner, and that these changes may account for the proposed schizophrenia-like phenotype of MD rats. The impact of MD on cannabinoid receptor distribution in the hippocampus is unknown. The aim of this study is to evaluate the expression of CB(1) and CB(2) receptors in diverse relevant subregions (DG, CA1, and CA3) of the hippocampus in 13-day-old rats by immunohistochemistry and densitometry. MD induced a significant decrease in CB(1) immunoreactivity (more marked in males than in females), which was mainly associated with fibers in the strata pyramidale and radiatum of CA1 and in the strata oriens, pyramidale, and radiatum of CA3. In contrast, MD males and females showed a significant increase in CB(2) immunoreactivity in the three hippocampal areas analyzed that was detected in neuropil and puncta in the stratum oriens of CA1 and CA3, and in the polymorphic cell layer of the dentate gyrus. A marked sex dimorphism was observed in CA3, with females exhibiting higher CB(1) immunoreactivity than males, and in dentate gyrus, with females exhibiting lower CB(2) immunoreactivity than males. These results point to a clear association between developmental stress and dysregulation of the ECS. The present MD procedure may provide an interesting experimental model to further address the role of the ECS in neurodevelopmental mental illnesses such as schizophrenia.

  16. Antinociceptive effects of the non-selective cannabinoid receptor agonist CP 55,940 are absent in CB1(-/-) and not CB2(-/-) mice in models of acute and persistent pain.

    Science.gov (United States)

    Sain, Nova M H; Liang, Annie; Kane, Stefanie A; Urban, Mark O

    2009-09-01

    Previous studies have suggested a role for both CB1 and CB2 cannabinoid receptors in modulation of nociception. To further examine the role of CB1 and CB2 receptors in antinociception, we evaluated the efficacy of the non-selective cannabinoid receptor agonist, CP 55,940, in models of acute, inflammatory, and neuropathic pain in control mice, CB1 receptor knockout mice, and CB2 receptor knockout mice. In control C57BL/6 mice, administration of CP 55,940 (0.03-0.3 mg/kg, i.p.) reversed complete Freund's adjuvant-induced tactile allodynia, reversed tactile allodynia in the spinal nerve ligation model and inhibited the noxious heat-evoked tail withdrawal response. In addition to its antinociceptive effects, CP 55,940 produced an impairment of motor coordination in the rotarod test. The antinociceptive effects produced by CP 55,940 and associated motor deficits were found to be completely abolished in CB1 receptor knockout mice. In contrast, the antinociceptive effects of CP 55,940 in all pain models were fully retained in CB2 receptor knockout mice, along with the associated motor deficits. The results suggest that the antinociceptive effects of CP 55,940 in models of acute and persistent pain, along with the associated motor deficits, are mediated by CB1 receptors, and likely not CB2 receptors.

  17. FAAH inhibitor, URB-597, promotes extinction and CB(1) antagonist, SR141716, inhibits extinction of conditioned aversion produced by naloxone-precipitated morphine withdrawal, but not extinction of conditioned preference produced by morphine in rats.

    Science.gov (United States)

    Manwell, Laurie A; Satvat, Elham; Lang, Stefan T; Allen, Craig P; Leri, Francesco; Parker, Linda A

    2009-11-01

    Converging evidence suggests that the endogenous cannabinoid (eCB) system is involved in extinction of learned behaviours. Using operant and classical conditioning procedures, the potential of the fatty acid amide (FAAH) inhibitor, URB-597, and the CB(1) antagonist/inverse agonist, SR141716, to promote and inhibit (respectively) extinction of learned responses previously motivated by either rewarding or aversive stimuli was investigated. In the operant conditioning procedure (Expt. 1), rats previously trained to lever press for sucrose reward were administered URB-597 (0.3 mg/kg) or the CB(1) antagonist/inverse agonist SR141716 (2.5 mg/kg) prior to each of three extinction trials. In the conditioned floor preference procedure (Expts 2a-d), rats trained to associate morphine with one of two distinctive floors were administered one of several doses of the CB(1) antagonist/inverse agonist, AM-251 (Expt 2a) or URB-597 (Expt 2b and 2d) prior to each extinction/test trial wherein a choice of both floors was presented and prior to forced exposure to each floor (Expt 2c). In the conditioned floor aversion procedure (Expt. 3), rats trained to associate a naloxone-precipitated morphine withdrawal with a floor cue were administered URB-597 or SR141716 prior to each of 24 extinction/testing trials. URB-597 did not promote and SR141716 did not reduce extinction rates for sucrose reward-induced operant responding (Expt. 1) or morphine-induced conditioned floor preference (Expts. 2a-d). In contrast, URB-597 facilitated, whereas SR141716 impaired, extinction of the conditioned floor aversion (Expt. 3). These data support previous reports that the eCB system selectively facilitates extinction of aversive memories. URB-597 may prove useful in targeting extinction of aversively motivated behaviours.

  18. Cannabinoid receptors are widely expressed in goldfish: molecular cloning of a CB2-like receptor and evaluation of CB1 and CB2 mRNA expression profiles in different organs.

    Science.gov (United States)

    Cottone, Erika; Pomatto, Valentina; Cerri, Fulvio; Campantico, Ezio; Mackie, Ken; Delpero, Massimiliano; Guastalla, Alda; Dati, Claudio; Bovolin, Patrizia; Franzoni, Maria Fosca

    2013-10-01

    Cannabinoids, the bioactive constituents of Cannabis sativa, and endocannabinoids, among which the most important are anandamide and 2-arachidonoylglycerol, control various biological processes by binding to specific G protein-coupled receptors, namely CB1 and CB2 cannabinoid receptors. While a vast amount of information on the mammalian endocannabinoid system does exist, few data have been reported on bony fish. In the goldfish, Carassius auratus, the CB1 receptor has been cloned and its distribution has been analyzed in the retina, brain and gonads, while CB2 had not yet been isolated. In the present paper, we cloned the goldfish CB2 receptor and show that it presents a quite high degree of amino acid identity with zebrafish Danio rerio CB2A and CB2B receptors, while the percentage of identity is lower with the puffer fish Fugu rubripes CB2, as also confirmed by the phylogenetic analysis. The sequence identity becomes much lower when comparing the goldfish and the mammalian CB2 sequences; as for other species, goldfish CB2 and CB1 amino acid sequences share moderate levels of identity. Western-blotting analysis shows the CB2 receptor as two major bands of about 53 and 40 kDa and other faint bands with apparent molecular masses around 70, 57 and 55 kDa. Since the distribution of a receptor could give information on its physiological role, we evaluated and compared CB1 and CB2 mRNA expression in different goldfish organs by means of qReal-Time PCR. Our results show that both CB1 and CB2 receptors are widely expressed in the goldfish, displaying some tissue specificities, thus opening the way for further functional studies on bony fish and other nonmammalian vertebrates.

  19. Comparative molecular dynamics simulations of the potent synthetic classical cannabinoid ligand AMG3 in solution and at binding site of the CB1 and CB2 receptors.

    Science.gov (United States)

    Durdagi, Serdar; Reis, Heribert; Papadopoulos, Manthos G; Mavromoustakos, Thomas

    2008-08-01

    The C-1'-dithiolane Delta(8)-tetrahydrocannabinol (Delta(8)-THC) amphiphilic analogue (-)-2-(6a,7,10,10a-tetrahydro-6,6,9-trimethylhydroxy-6H-dibenzo[b,d]pyranyl)-2-hexyl-1,3-dithiolane (AMG3) is considered as one of the most potent synthetic analgesic cannabinoid (CB) ligands. Its structure is characterized by rigid tricyclic and flexible alkyl chain segments. Its conformational properties have not been fully explored. Structure-activity relationship (SAR) studies on classical CBs showed that the alkyl side chain is the most critical structural part for the receptor activation. However, reported low energy conformers of classical CB analogues vary mainly in the conformation of their alkyl side chain segment. Therefore, comparative molecular dynamics (MD) simulations of low energy conformers of AMG3 were performed in order to investigate its structural and dynamical properties in two different systems. System-I includes ligand and amphoteric solvent DMSO, simulating the biological environment and system-II includes ligand at active site of the homology models of CB1 and CB2 receptors in the solvent. The trajectory analysis results are compared for the systems I and II. In system-I, the dihedral angle defined between aromatic ring and dithiolane ring of AMG3 shows more resistance to be transformed into another torsional angle and the dihedral angle adjacent to dithiolane ring belonging in the alkyl chain has flexibility to adopt gauche+/- and trans dihedral angles. The rest of the dihedral angles within the alkyl chain are all trans. These results point out that wrapped conformations are dynamically less favored in solution than linear conformations. Two possible plane angles defined between the rigid and flexible segments are found to be the most favored and adopting values of approximately 90 degrees and approximately 140 degrees. In system-II, these values are approximately 90 degrees and approximately 120 degrees. Conformers of AMG3 at the CB1 receptor favor to

  20. Maternal deprivation and adolescent cannabinoid exposure impact hippocampal astrocytes, CB1 receptors and brain-derived neurotrophic factor in a sexually dimorphic fashion.

    Science.gov (United States)

    López-Gallardo, M; López-Rodríguez, A B; Llorente-Berzal, Á; Rotllant, D; Mackie, K; Armario, A; Nadal, R; Viveros, M-P

    2012-03-01

    We have recently reported that early maternal deprivation (MD) for 24 h [postnatal day (PND) 9-10] and/or an adolescent chronic treatment with the cannabinoid agonist CP-55,940 (CP) [0.4 mg/kg, PND 28-42] in Wistar rats induced, in adulthood, diverse sex-dependent long-term behavioral and physiological modifications. Here we show the results obtained from investigating the immunohistochemical analysis of CB1 cannabinoid receptors, glial fibrillary acidic protein (GFAP) positive (+) cells and brain-derived neurotrophic factor (BDNF) expression in the hippocampus of the same animals. MD induced, in males, a significant increase in the number of GFAP+ cells in CA1 and CA3 areas and in the polymorphic layer of the dentate gyrus (DG), an effect that was attenuated by CP in the two latter regions. Adolescent cannabinoid exposure induced, in control non-deprived males, a significant increase in the number of GFAP+ cells in the polymorphic layer of the DG. MD induced a decrease in CB1 expression in both sexes, and this effect was reversed in males by the cannabinoid treatment. In turn, the drug "per se" induced, in males, a general decrease in CB1 immunoreactivity, and the opposite effect was observed in females. Cannabinoid exposure tended to reduce BDNF expression in CA1 and CA3 of females, whereas MD counteracted this trend and induced an increase of BDNF in females. As a whole, the present results show sex-dependent long-term effects of both MD and juvenile cannabinoid exposure as well as functional interactions between the two treatments.

  1. Localization of the cannabinoid CB1 receptor and the 2-AG synthesizing (DAGLα) and degrading (MAGL, FAAH) enzymes in cells expressing the Ca2+-binding proteins calbindin, calretinin, and parvalbumin in the adult rat hippocampus

    OpenAIRE

    Patricia eRivera; Sergio eArrabal; Manuel eCifuentes; Grondona, Jesús M; Margarita ePérez-Martín; Leticia eRubio; Antonio eVargas Fuentes; Antonia eSerrano; Francisco Javier ePavon; Juan eSuarez; Fernando eRodríguez de Fonseca

    2014-01-01

    The retrograde suppression of the synaptic transmission by the endocannabinoid sn-2-arachidonoylglycerol (2-AG) is mediated by the cannabinoid CB1 receptors and requires the elevation of intracellular Ca2+ and the activation of specific 2-AG synthesizing (i.e., DAGLα) enzymes. However, the anatomical organization of the neuronal substrates that express 2-AG/CB1 signaling system-related molecules associated with selective Ca2+-binding proteins (CaBPs) is still unknown. For this purpose, we use...

  2. The Combined Inhibitory Effect of the Adenosine A1 and Cannabinoid CB1 Receptors on cAMP Accumulation in the Hippocampus Is Additive and Independent of A1 Receptor Desensitization

    Directory of Open Access Journals (Sweden)

    André Serpa

    2015-01-01

    Full Text Available Adenosine A1 and cannabinoid CB1 receptors are highly expressed in hippocampus where they trigger similar transduction pathways. We investigated how the combined acute activation of A1 and CB1 receptors modulates cAMP accumulation in rat hippocampal slices. The CB1 agonist WIN55212-2 (0.3–30 μM decreased forskolin-stimulated cAMP accumulation with an EC50 of 6.6 ± 2.7 μM and an Emax⁡ of 31% ± 2%, whereas for the A1 agonist, N6-cyclopentyladenosine (CPA, 10–150 nM, an EC50 of 35 ± 19 nM, and an Emax⁡ of 29% ± 5 were obtained. The combined inhibitory effect of WIN55212-2 (30 μM and CPA (100 nM on cAMP accumulation was 41% ± 6% (n=4, which did not differ (P>0.7 from the sum of the individual effects of each agonist (43% ± 8% but was different (P<0.05 from the effects of CPA or WIN55212-2 alone. Preincubation with CPA (100 nM for 95 min caused desensitization of adenosine A1 activity, which did not modify the effect of WIN55212-2 (30 μM on cAMP accumulation. In conclusion, the combined effect of CB1 and A1 receptors on cAMP formation is additive and CB1 receptor activity is not affected by short-term A1 receptor desensitization.

  3. The combined inhibitory effect of the adenosine A1 and cannabinoid CB1 receptors on cAMP accumulation in the hippocampus is additive and independent of A1 receptor desensitization.

    Science.gov (United States)

    Serpa, André; Correia, Sara; Ribeiro, Joaquim A; Sebastião, Ana M; Cascalheira, José F

    2015-01-01

    Adenosine A1 and cannabinoid CB1 receptors are highly expressed in hippocampus where they trigger similar transduction pathways. We investigated how the combined acute activation of A1 and CB1 receptors modulates cAMP accumulation in rat hippocampal slices. The CB1 agonist WIN55212-2 (0.3-30 μM) decreased forskolin-stimulated cAMP accumulation with an EC50 of 6.6±2.7 μM and an Emax of 31%±2%, whereas for the A1 agonist, N6-cyclopentyladenosine (CPA, 10-150 nM), an EC50 of 35±19 nM, and an Emax of 29%±5 were obtained. The combined inhibitory effect of WIN55212-2 (30 μM) and CPA (100 nM) on cAMP accumulation was 41%±6% (n=4), which did not differ (P>0.7) from the sum of the individual effects of each agonist (43%±8%) but was different (Peffects of CPA or WIN55212-2 alone. Preincubation with CPA (100 nM) for 95 min caused desensitization of adenosine A1 activity, which did not modify the effect of WIN55212-2 (30 μM) on cAMP accumulation. In conclusion, the combined effect of CB1 and A1 receptors on cAMP formation is additive and CB1 receptor activity is not affected by short-term A1 receptor desensitization.

  4. Population-based input function modeling for [(18F]FMPEP-d 2, an inverse agonist radioligand for cannabinoid CB1 receptors: validation in clinical studies.

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    Paolo Zanotti-Fregonara

    Full Text Available BACKGROUND: Population-based input function (PBIF may be a valid alternative to full blood sampling for quantitative PET imaging. PBIF is typically validated by comparing its quantification results with those obtained via arterial sampling. However, for PBIF to be employed in actual clinical research studies, its ability to faithfully capture the whole spectrum of results must be assessed. The present study validated a PBIF for [(18F]FMPEP-d 2, a cannabinoid CB1 receptor radioligand, in healthy volunteers, and also attempted to utilize PBIF to replicate three previously published clinical studies in which the input function was acquired with arterial sampling. METHODS: The PBIF was first created and validated with data from 42 healthy volunteers. This PBIF was used to assess the retest variability of [(18F]FMPEP-d 2, and then to quantify CB1 receptors in alcoholic patients (n = 18 and chronic daily cannabis smokers (n = 29. Both groups were scanned at baseline and after 2-4 weeks of monitored drug abstinence. RESULTS: PBIF yielded accurate results in the 42 healthy subjects (average Logan-distribution volume (V T was 13.3±3.8 mL/cm(3 for full sampling and 13.2±3.8 mL/cm(3 for PBIF; R(2 = 0.8765, p<0.0001 and test-retest results were comparable to those obtained with full sampling (variability: 16%; intraclass correlation coefficient: 0.89. PBIF accurately replicated the alcoholism study, showing a widespread ∼20% reduction of CB1 receptors in alcoholic subjects, without significant change after abstinence. However, a small PBIF-V T bias of -9% was unexpectedly observed in cannabis smokers. This bias led to substantial errors, including a V T decrease in regions that had shown no downregulation in the full input function. Simulated data showed that the original findings could only have been replicated with a PBIF bias between -6% and +4%. CONCLUSIONS: Despite being initially well validated in healthy subjects, PBIF may

  5. Effects of CB1 receptor agonism and antagonism on behavioral fear and physiological stress responses in adult intact, ovariectomized, and estradiol-replaced female rats.

    Science.gov (United States)

    Simone, J J; Malivoire, B L; McCormick, C M

    2015-10-15

    There is growing interest in the development of cannabis-based therapies for the treatment of fear and anxiety disorders. There are a few studies, but none in females, of the effects of the highly selective cannabinoid receptor type 1 (CB1) agonist, arachidonyl 2'-chlorethylamide (ACEA), on behavioral fear. In experiment 1 involving gonadally-intact females, ACEA (either 0.1 or 0.01 mg/kg) was without effect in the elevated plus maze (EPM), and the lower dose decreased anxiety in the open field test (OFT). AM251 increased anxiety in the EPM and decreased locomotor activity in the OFT. Twenty-four hours after fear conditioning, neither ACEA nor AM251 affected generalized fear or conditioned fear recall. AM251 and 0.1 mg/kg ACEA impaired, and 0.01 mg/kg ACEA enhanced, within-session fear extinction. AM251 increased plasma corticosterone concentrations after the fear extinction session, whereas ACEA was without effect. Based on evidence that estradiol may moderate the effects of CB1 receptor signaling in females, experiment 2 involved ovariectomized (OVX) rats provided with 10-μg 17β-Estradiol and compared with OVX rats without hormone replacement (oil vehicle). Irrespective of hormone treatment, AM251 increased anxiety in the EPM, whereas ACEA (0.01 mg/kg) was without effect. Neither hormone nor drug altered anxiety in the OFT, but estradiol increased and AM251 decreased distance traveled. After fear conditioning, AM251 decreased generalized fear. Neither hormone nor drug had any effect on recall or extinction of conditioned fear, however, ACEA and AM251 increased fear-induced plasma corticosterone concentrations. Further, when results with intact rats were compared with those from OVX rats, gonadal status did not moderate the effects of either AM251 or ACEA, although OVX displayed greater anxiety and fear than did intact rats. Thus, the effects of CB1 receptor antagonism and agonism in adult female rats do not depend on ovarian estradiol.

  6. Prolonged exposure to WIN55,212-2 causes downregulation of the CB1 receptor and the development of tolerance to its anticonvulsant effects in the hippocampal neuronal culture model of acquired epilepsy.

    Science.gov (United States)

    Blair, Robert E; Deshpande, Laxmikant S; Sombati, Sompong; Elphick, Maurice R; Martin, Billy R; DeLorenzo, Robert J

    2009-09-01

    Cannabinoids have been shown to cause CB1-receptor-dependent anticonvulsant activity in both in vivo and in vitro models of status epilepticus (SE) and acquired epilepsy (AE). It has been further demonstrated in these models that the endocannabinoid system functions in a tonic manner to suppress seizure discharges through a CB1-receptor-dependent pathway. Although acute cannabinoid treatment has anticonvulsant activity, little is known concerning the effects of prolonged exposure to CB1 agonists and development of tolerance on the epileptic phenotype. This study was carried out to evaluate the effects of prolonged exposure to the CB1 agonist WIN55,212-2 on seizure activity in a hippocampal neuronal culture model of low-Mg(2+) induced spontaneous recurrent epileptiform discharges (SREDs). Following low-Mg(2+) induced SREDs, cultures were returned to maintenance media containing 10, 100 or 1000 nM WIN55,212-2 from 4 to 24 h. Whole-cell current-clamp analysis of WIN55,212-2 treated cultures revealed a concentration-dependent increase in SRED frequency. Immunocytochemical staining revealed that WIN55,212-2 treatment induced a concentration-dependent downregulation of the CB1 receptor in neuronal processes and at both glutamatergic and GABAergic presynaptic terminals. Prolonged exposure to the inactive enantiomer WIN55,212-3 in low-Mg(2+) treated cultures had no effect on the frequency of SREDs or CB1 receptor staining. The results from this study further substantiate a role for a tonic CB1-receptor-dependent endocannabinoid regulation of seizure discharge and suggest that prolonged exposure to cannabinoids results in the development of tolerance to the anticonvulsant effects of cannabinoids and an exacerbation of seizure activity in the epileptic phenotype.

  7. Prolonged exposure to WIN55,212-2 causes down-regulation of the CB1 receptor and the development of tolerance to its anticonvulsant effects in the hippocampal neuronal culture model of acquired epilepsy

    Science.gov (United States)

    Blair, Robert E.; Deshpande, Laxmikant S.; Sombati, Sompong; Elphick, Maurice R.; Martin, Billy R.; DeLorenzo, Robert J.

    2009-01-01

    Summary Cannabinoids have been shown to cause CB1-receptor dependent anticonvulsant activity in both in vivo and in vitro models of status epilepticus (SE) and acquired epilepsy (AE). It has been further demonstrated in these models that the endocannabinoid system functions in a tonic manner to suppress seizure discharges through a CB1-receptor dependent pathway. Although acute cannabinoid treatment has anticonvulsant activity, little is known concerning the effects of prolonged exposure to CB1 agonists and development of tolerance on the epileptic phenotype. This study was carried out to evaluate the effects of prolonged exposure to the CB1 agonist WIN55,212-2 on seizure activity in a hippocampal neuronal culture model of low-Mg2+ induced spontaneous recurrent epileptiform discharges (SREDs). Following low-Mg2+ induced SREDs, cultures were returned to maintenance media containing 10, 100 or 1000 nM WIN55,212-2 from 4 to 24 hours. Whole-cell current-clamp analysis of WIN55,212-2 treated cultures revealed a concentration-dependent increase in SRED frequency. Immunocytochemical staining revealed that WIN55,212-2 treatment induced a concentration-dependent down-regulation of the CB1 receptor in neuronal processes and at both glutamatergic and GABAergic presynaptic terminals. Prolonged exposure to the inactive enantiomer WIN55,212-3 in low-Mg2+ treated cultures had no effect on the frequency of SREDs or CB1 receptor staining. The results from this study further substantiate a role for a tonic CB1 receptor-dependent endocannabinoid regulation of seizure discharge and suggest that prolonged exposure to cannabinoids results in the development of tolerance to the anticonvulsant effects of cannabinoids and an exacerbation of seizure activity in the epileptic phenotype. PMID:19540252

  8. Enhanced self-administration of the CB1 receptor agonist WIN55,212-2 in olfactory bulbectomized rats: evaluation of possible serotonergic and dopaminergic underlying mechanisms

    Directory of Open Access Journals (Sweden)

    Petra eAmchova

    2014-03-01

    Full Text Available Depression has been associated with drug consumption, including heavy or problematic cannabis use. According to an animal model of depression and substance use disorder comorbidity, we combined the olfactory bulbectomy model of depression with intravenous drug self-administration procedure to verify whether depressive-like rats displayed higher voluntary intake of the CB1 receptor agonist WIN55,212-2 (WIN, 12.5 µg/kg/infusion. To this aim, olfactory-bulbectomized (OBX and sham-operated (SHAM Lister Hooded rats were allowed to self-administer WIN by lever-pressing under a continuous (FR-1 schedule of reinforcement in 2h daily sessions. Data showed that both OBX and SHAM rats developed stable WIN intake; yet, responses in OBX were constantly higher than in SHAM rats soon after the first week of training. In addition, OBX rats took significantly longer to extinguish the drug-seeking behaviour after vehicle substitution. Acute pre-treatment with serotonin 5HT1B receptor agonist, CGS-12066B (2.5-10 mg/kg, did not significantly modify WIN intake in OBX and SHAM Lister Hooded rats. Furthermore, acute pre-treatment with CGS-12066B (10 and 15 mg/kg did not alter responses in parallel groups of OBX and SHAM Sprague Dawley rats self-administering methamphetamine under higher (FR-2 reinforcement schedule with nose-poking as operandum. Finally, dopamine levels in the nucleus accumbens of OBX rats did not increase in response to a WIN challenge, as in SHAM rats, indicating a dopaminergic dysfunction in bulbectomized rats. Altogether, our findings suggest that a depressive state may alter cannabinoid CB1 receptor agonist-induced brain reward function and that a dopaminergic rather than a 5-HT1B mechanism is likely to underlie enhanced WIN self-administration in OBX rats.

  9. Neuroprotective effect of WIN55,212-2 against 3-nitropropionic acid-induced toxicity in the rat brain: involvement of CB1 and NMDA receptors

    Science.gov (United States)

    Maya-López, Marisol; Colín-González, Ana Laura; Aguilera, Gabriela; de Lima, María Eduarda; Colpo-Ceolin, Ana; Rangel-López, Edgar; Villeda-Hernández, Juana; Rembao-Bojórquez, Daniel; Túnez, Isaac; Luna-López, Armando; Lazzarini-Lechuga, Roberto; González-Puertos, Viridiana Yazmín; Posadas-Rodríguez, Pedro; Silva-Palacios, Alejandro; Königsberg, Mina; Santamaría, Abel

    2017-01-01

    The endocannabinoid system (ECS), and agonists acting on cannabinoid receptors (CBr), are known to regulate several physiological events in the brain, including modulatory actions on excitatory events probably through N-methyl-D-aspartate receptor (NMDAr) activity. Actually, CBr agonists can be neuroprotective. The synthetic CBr agonist WIN55,212-2 acts mainly on CB1 receptor. In turn, the mitochondrial toxin 3-nitropropionic acid (3-NP) produces striatal alterations in rats similar to those observed in the brain of Huntington’s disease patients. Herein, the effects of WIN55,212-2 were tested on different endpoints of the 3-NP-induced toxicity in rat brain synaptosomes and striatal tissue. Motor activity was also evaluated. The 3-NP (1 mM)-induced mitochondrial dysfunction and lipid peroxidation was attenuated by WIN55,212-2 (1 µM) in synaptosomal fractions. The intrastriatal bilateral injection of 3-NP (500 nmol/µL) to rats increased lipid peroxidation and locomotor activity, augmented the rate of cell damage, and decreased the striatal density of neuronal cells. These alterations were accompanied by transcriptional changes in the NMDA (NR1 subunit) content. The administration of WIN55212-2 (1 mg/kg, i.p.) to rats for six consecutive days, before the 3-NP injection, exerted preventive effects on all alterations elicited by the toxin. The prevention of the 3-NP-induced NR1 transcriptional alterations by the CBr agonist together with the increase of CB1 content suggest an early reduction of the excitotoxic process via CBr activation. Our results demonstrate a protective role of WIN55,212-2 on the 3-NP-induced striatal neurotoxicity that could be partially related to the ECS stimulation and induction of NMDAr hypofunction, representing an effective therapeutic strategy at the experimental level for further studies.

  10. Enhanced humoral immunity in mice lacking CB1 and CB2 receptors (Cnr1-/-/Cnr2-/- mice) is not due to increased splenic noradrenergic neuronal activity.

    Science.gov (United States)

    Simkins, Tyrell; Crawford, Robert B; Goudreau, John L; Lookingland, Keith J; Kaplan, Barbara L F

    2014-09-01

    Peripheral sympathetic noradrenergic neurons originating in the celiac mesenteric plexus have axons that terminate in close proximity to antibody-producing B cells in the spleen. Norepinephrine (NE) released from these neurons is reported to augment antibody production in response to an immune challenge via an action at the β2-adrenergic receptor (β2AR). Cannabinoids are immunosuppressive, and mice lacking CB1 and CB2 receptors (Cnr1(-/-)/Cnr2(-/-) mice) have augmented cell-mediated immune responses. The purpose of this study was to determine if Cnr1(-/-)/Cnr2(-/-) mice also exhibit enhanced humoral immunity and if that is associated with corresponding changes in noradrenergic neurons terminating in the spleen. The results reveal that IgM and IgG are enhanced in Cnr1(-/-)/Cnr2(-/-) mice as compared to WT both in immunologically naïve and lipopolysaccharide (LPS)-treated mice. While the elevated antibody production was correlated with increased expression of β2AR on splenic B cells and increased splenic capsule NE concentrations, the activity of noradrenergic neurons was suppressed in spleens from Cnr1(-/-)/Cnr2(-/-) mice as compared with WT controls. Together, these results suggest that Cnr1(-/-)/Cnr2(-/-) mice exhibit enhanced NE vesicular storage in axon terminals in these neurons, which might limit the NE available to bind β2AR on target cells, such as B cells. The results also demonstrate that enhanced antibody responses in the absence of CB1 and CB2 receptors are not due to increased sympathetic noradrenergic neuronal activity in the spleen.

  11. Effects of endocannabinoid 1 and 2 (CB1; CB2) receptor agonists on luteal weight, circulating progesterone, luteal mRNA for luteinizing hormone (LH) receptors, and luteal unoccupied and occupied receptors for LH in vivo in ewes.

    Science.gov (United States)

    Tsutahara, Nicole M; Weems, Yoshie S; Arreguin-Arevalo, J Alejandro; Nett, Torrance M; LaPorte, Magen E; Uchida, Janelle; Pang, Janelle; McBride, Tonya; Randel, Ronald D; Weems, Charles W

    2011-02-01

    Thirty to forty percent of ruminant pregnancies are lost during the first third of gestation due to inadequate progesterone secretion. During the estrous cycle, luteinizing hormone (LH) regulates progesterone secretion by small luteal cells (SLC). Loss of luteal progesterone secretion during the estrous cycle is increased via uterine secretion of prostaglandin F(2α) (PGF(2α)) starting on days 12-13 post-estrus in ewes with up to 4-6 pulses per day. Prostaglandin F(2α) is synthesized from arachidonic acid, which is released from phospholipids by phospholipase A2. Endocannabinoids are also derived from phospholipids and are associated with infertility. Endocannabinoid-induced infertility has been postulated to occur primarily via negative effects on implantation. Cannabinoid (CB) type 1 (CB1) or type 2 (CB2) receptor agonists and an inhibitor of the enzyme fatty acid amide hydrolase, which catabolizes endocannabinoids, decreased luteal progesterone, prostaglandin E (PGE), and prostaglandin F(2α) (PGF(2α)) secretion by the bovine corpus luteum in vitro by 30 percent. The objective of the experiment described herein was to determine whether CB1 or CB2 receptor agonists given in vivo affect circulating progesterone, luteal weights, luteal mRNA for LH receptors, and luteal occupied and unoccupied LH receptors during the estrous cycle of ewes. Treatments were: Vehicle, Methanandamide (CB1 agonist; METH), or 1-(4-chlorobenzoyl)-5-methoxy-1H-indole-3-acetic acid morpholineamide (CB2 agonist; IMMA). Ewes received randomized treatments on day 10 post-estrus. A single treatment (500 μg; N=5/treatment group) in a volume of 1 ml was given into the interstitial tissue of the ovarian vascular pedicle adjacent to the luteal-containing ovary. Jugular venous blood was collected at 0 h and every 6-48 h for the analysis of progesterone by radioimmunoassay (RIA). Corpora lutea were collected at 48 h, weighed, bisected, and frozen in liquid nitrogen until analysis of unoccupied and

  12. AM-251 and rimonabant act as direct antagonists at mu-opioid receptors: implications for opioid/cannabinoid interaction studies.

    Science.gov (United States)

    Seely, Kathryn A; Brents, Lisa K; Franks, Lirit N; Rajasekaran, Maheswari; Zimmerman, Sarah M; Fantegrossi, William E; Prather, Paul L

    2012-10-01

    Mu-opioid and CB1-cannabinoid agonists produce analgesia; however, adverse effects limit use of drugs in both classes. Additive or synergistic effects resulting from concurrent administration of low doses of mu- and CB1-agonists may produce analgesia with fewer side effects. Synergism potentially results from interaction between mu-opioid receptors (MORs) and CB1 receptors (CB1Rs). AM-251 and rimonabant are CB1R antagonist/inverse agonists employed to validate opioid-cannabinoid interactions, presumed to act selectively at CB1Rs. Therefore, the potential for direct action of these antagonists at MORs is rarely considered. This study determined if AM-251 and/or rimonabant directly bind and modulate the function of MORs. Surprisingly, AM-251 and rimonabant, but not a third CB1R inverse agonist AM-281, bind with mid-nanomolar affinity to human MORs with a rank order of affinity (K(i)) of AM-251 (251 nM) > rimonabant (652 nM) > AM281 (2135 nM). AM-251 and rimonabant, but not AM-281, also competitively antagonize morphine induced G-protein activation in CHO-hMOR cell homogenates (K(b) = 719 or 1310 nM, respectively). AM-251 and rimonabant block morphine inhibition of cAMP production, while only AM-251 elicits cAMP rebound in CHO-hMOR cells chronically exposed to morphine. AM-251 and rimonabant (10 mg/kg) attenuate morphine analgesia, whereas the same dose of AM-281 produces little effect. Therefore, in addition to high CB1R affinity, AM-251 and rimonabant bind to MORs with mid-nanomolar affinity and at higher doses may affect morphine analgesia via direct antagonism at MORs. Such CB1-independent of these antagonists effects may contribute to reported inconsistencies when CB1/MOR interactions are examined via pharmacological methods in CB1-knockout versus wild-type mice.

  13. CB1 Cannabinoid Agonist (WIN55,212-2) Within the Basolateral Amygdala Induced Sensitization to Morphine and Increased the Level of μ-Opioid Receptor and c-fos in the Nucleus Accumbens.

    Science.gov (United States)

    Molaei, Marzieh; Fatahi, Zahra; Zaringhalam, Jalal; Haghparast, Abbas

    2016-04-01

    The basolateral amygdala (BLA) is rich of CB1 cannabinoid receptors (CB1R) and has reciprocal connections with the nucleus accumbens (NAc) which is involved in opioid sensitization. In this study, effects of intra-BLA administration of CB1R agonist on sensitization to antinociceptive effect of morphine and changes in the levels of μ-opioid receptor (MOR), p-CREB, and c-fos in the NAc were investigated. Animals received intra-BLA microinjection of CB1R agonist (WIN55,212-2) once daily for 3 days consecutively (sensitization period). After 5 days free of drug, tail-flick test was performed before and after the administration of an ineffective dose of morphine. Afterward, the levels of MOR, p-CREB, and c-fos proteins were measured in the NAc by Western blot analysis. The results indicated that intra-BLA injection of WIN55,212-2 during sensitization period resulted in the induction of antinociceptive responses by ineffective dose of morphine and caused a significant increase in the MOR and c-fos levels but not p-CREB/CREB ratio in the NAc. These finding revealed that CB1 receptor agonist in the BLA induces development of morphine sensitization and increases expression of MOR in the NAc. It seems that c-fos is one of the important factors involved in the induction of sensitization to antinociceptive effect of morphine.

  14. Excitatory amino acid receptor antagonists

    DEFF Research Database (Denmark)

    Johansen, T N; Frydenvang, Karla Andrea; Ebert, B

    1997-01-01

    We have previously shown that (RS)-2-amino-2-(5-tert-butyl-3-hydroxyisoxazol-4-yl)acetic acid (ATAA) is an antagonist at N-methyl-D-aspartic acid (NMDA) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors. We have now resolved ATAA via diastereomeric salt formation......)-phenylethylamine salt of N-BOC-(R)-ATAA. Like ATAA, neither (R)- nor (S)-ATAA significantly affected (IC50 > 100 microM) the receptor binding of tritiated AMPA, kainic acid, or (RS)-3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid, the latter being a competitive NMDA antagonist. Electrophysiological experiments......, using the rat cortical wedge preparation, showed the NMDA antagonist effect as well as the AMPA antagonist effect of ATAA to reside exclusively in the (R)-enantiomer (Ki = 75 +/- 5 microM and 57 +/- 1 microM, respectively). Neither (R)- nor (S)-ATAA significantly reduced kainic acid-induced excitation...

  15. Activation of CB1 and CB2 receptors attenuates the induction and maintenance of inflammatory pain in the rat.

    Science.gov (United States)

    Elmes, Steven J R; Winyard, Lisa A; Medhurst, Stephen J; Clayton, Nick M; Wilson, Alex W; Kendall, David A; Chapman, Victoria

    2005-12-01

    The aim of the present study was to investigate the effects of cannabinoid agonists on established inflammatory hyperalgesia. We have compared the effects of pre-administration versus post-administration of a potent non-selective cannabinoid agonist HU210 and a selective CB2 receptor agonist JWH-133 on hindpaw weight bearing and paw oedema in the carrageenan model of inflammatory hyperalgesia. For comparative purposes we also determined the effects of the mu-opioid receptor agonist morphine and the COX2 inhibitor rofecoxib in this model. At 3 h following intraplantar injection of carrageenan (2%, 100 microl) there was a significant (P pain responses.

  16. Localization of the cannabinoid CB1 receptor and the 2-AG synthesizing (DAGLα) and degrading (MAGL, FAAH) enzymes in cells expressing the Ca2+-binding proteins calbindin, calretinin, and parvalbumin in the adult rat hippocampus

    Science.gov (United States)

    Rivera, Patricia; Arrabal, Sergio; Cifuentes, Manuel; Grondona, Jesús M.; Pérez-Martín, Margarita; Rubio, Leticia; Vargas, Antonio; Serrano, Antonia; Pavón, Francisco J.; Suárez, Juan; Rodríguez de Fonseca, Fernando

    2014-01-01

    The retrograde suppression of the synaptic transmission by the endocannabinoid sn-2-arachidonoylglycerol (2-AG) is mediated by the cannabinoid CB1 receptors and requires the elevation of intracellular Ca2+ and the activation of specific 2-AG synthesizing (i.e., DAGLα) enzymes. However, the anatomical organization of the neuronal substrates that express 2-AG/CB1 signaling system-related molecules associated with selective Ca2+-binding proteins (CaBPs) is still unknown. For this purpose, we used double-label immunofluorescence and confocal laser scanning microscopy for the characterization of the expression of the 2-AG/CB1 signaling system (CB1 receptor, DAGLα, MAGL, and FAAH) and the CaBPs calbindin D28k, calretinin, and parvalbumin in the rat hippocampus. CB1, DAGLα, and MAGL labeling was mainly localized in fibers and neuropil, which were differentially organized depending on the hippocampal CaBPs-expressing cells. CB+1 fiber terminals localized in all hippocampal principal cell layers were tightly attached to calbindin+ cells (granular and pyramidal neurons), and calretinin+ and parvalbumin+ interneurons. DAGLα neuropil labeling was selectively found surrounding calbindin+ principal cells in the dentate gyrus and CA1, and in the calretinin+ and parvalbumin+ interneurons in the pyramidal cell layers of the CA1/3 fields. MAGL+ terminals were only observed around CA1 calbindin+ pyramidal cells, CA1/3 calretinin+ interneurons and CA3 parvalbumin+ interneurons localized in the pyramidal cell layers. Interestingly, calbindin+ pyramidal cells expressed FAAH specifically in the CA1 field. The identification of anatomically related-neuronal substrates that expressed 2-AG/CB1 signaling system and selective CaBPs should be considered when analyzing the cannabinoid signaling associated with hippocampal functions. PMID:25018703

  17. Localization of the cannabinoid CB1 receptor and the 2-AG synthesizing (DAGLα and degrading (MAGL, FAAH enzymes in cells expressing the Ca2+-binding proteins calbindin, calretinin and parvalbumin in the adult rat hippocampus

    Directory of Open Access Journals (Sweden)

    Patricia eRivera

    2014-06-01

    Full Text Available The retrograde suppression of the synaptic transmission by the endocannabinoid sn-2-arachidonoylglycerol (2-AG is mediated by the cannabinoid CB1 receptors and requires the elevation of intracellular Ca2+ and the activation of specific 2-AG synthesizing (i.e. DAGLα enzymes. However, the anatomical organization of the neuronal substrates that express 2-AG/CB1 signaling system-related molecules associated with selective Ca2+-binding proteins (CaBPs is still unknown. For this purpose, we used double-label immunofluorescence and confocal laser scanning microscopy for the characterization of the expression of the 2-AG/CB1 signaling system (CB1 receptor, DAGLα, MAGL and FAAH and the CaBPs calbindin D28k, calretinin and parvalbumin in the rat hippocampus. CB1, DAGLα and MAGL labeling was mainly localized in fibers and neuropil, which were differentially organized depending on the hippocampal CaBPs-expressing cells. CB1+ fiber terminals localized in all hippocampal principal cell layers were tightly attached to calbindin+ cells (granular and pyramidal neurons, and calretinin+ and parvalbumin+ interneurons. DAGLα neuropil labeling was selectively found surrounding calbindin+ principal cells in the dentate gyrus and CA1, and in the calretinin+ and parvalbumin+ interneurons in the pyramidal cell layers of the CA1/3 fields. MAGL+ terminals were only observed around CA1 calbindin+ pyramidal cells, CA1/3 calretinin+ interneurons and CA3 parvalbumin+ interneurons localized in the pyramidal cell layers. Interestingly, calbindin+ pyramidal cells expressed FAAH specifically in the CA1 field. The identification of anatomically related-neuronal substrates that expressed 2-AG/CB1 signaling system and selective CaBPs should be considered when analyzing the cannabinoid signaling associated with hippocampal functions.

  18. Localization of the cannabinoid CB1 receptor and the 2-AG synthesizing (DAGLα) and degrading (MAGL, FAAH) enzymes in cells expressing the Ca(2+)-binding proteins calbindin, calretinin, and parvalbumin in the adult rat hippocampus.

    Science.gov (United States)

    Rivera, Patricia; Arrabal, Sergio; Cifuentes, Manuel; Grondona, Jesús M; Pérez-Martín, Margarita; Rubio, Leticia; Vargas, Antonio; Serrano, Antonia; Pavón, Francisco J; Suárez, Juan; Rodríguez de Fonseca, Fernando

    2014-01-01

    The retrograde suppression of the synaptic transmission by the endocannabinoid sn-2-arachidonoylglycerol (2-AG) is mediated by the cannabinoid CB1 receptors and requires the elevation of intracellular Ca(2+) and the activation of specific 2-AG synthesizing (i.e., DAGLα) enzymes. However, the anatomical organization of the neuronal substrates that express 2-AG/CB1 signaling system-related molecules associated with selective Ca(2+)-binding proteins (CaBPs) is still unknown. For this purpose, we used double-label immunofluorescence and confocal laser scanning microscopy for the characterization of the expression of the 2-AG/CB1 signaling system (CB1 receptor, DAGLα, MAGL, and FAAH) and the CaBPs calbindin D28k, calretinin, and parvalbumin in the rat hippocampus. CB1, DAGLα, and MAGL labeling was mainly localized in fibers and neuropil, which were differentially organized depending on the hippocampal CaBPs-expressing cells. CB(+) 1 fiber terminals localized in all hippocampal principal cell layers were tightly attached to calbindin(+) cells (granular and pyramidal neurons), and calretinin(+) and parvalbumin(+) interneurons. DAGLα neuropil labeling was selectively found surrounding calbindin(+) principal cells in the dentate gyrus and CA1, and in the calretinin(+) and parvalbumin(+) interneurons in the pyramidal cell layers of the CA1/3 fields. MAGL(+) terminals were only observed around CA1 calbindin(+) pyramidal cells, CA1/3 calretinin(+) interneurons and CA3 parvalbumin(+) interneurons localized in the pyramidal cell layers. Interestingly, calbindin(+) pyramidal cells expressed FAAH specifically in the CA1 field. The identification of anatomically related-neuronal substrates that expressed 2-AG/CB1 signaling system and selective CaBPs should be considered when analyzing the cannabinoid signaling associated with hippocampal functions.

  19. Activation of CB1 inhibits NGF-induced sensitization of TRPV1 in adult mouse afferent neurons.

    Science.gov (United States)

    Wang, Z-Y; McDowell, T; Wang, P; Alvarez, R; Gomez, T; Bjorling, D E

    2014-09-26

    Transient receptor potential vanilloid 1 (TRPV1)-containing afferent neurons convey nociceptive signals and play an essential role in pain sensation. Exposure to nerve growth factor (NGF) rapidly increases TRPV1 activity (sensitization). In the present study, we investigated whether treatment with the selective cannabinoid receptor 1 (CB1) agonist arachidonyl-2'-chloroethylamide (ACEA) affects NGF-induced sensitization of TRPV1 in adult mouse dorsal root ganglion (DRG) afferent neurons. We found that CB1, NGF receptor tyrosine kinase A (trkA), and TRPV1 are present in cultured adult mouse small- to medium-sized afferent neurons and treatment with NGF (100ng/ml) for 30 min significantly increased the number of neurons that responded to capsaicin (as indicated by increased intracellular Ca(2 +) concentration). Pretreatment with the CB1 agonist ACEA (10nM) inhibited the NGF-induced response, and this effect of ACEA was reversed by a selective CB1 antagonist. Further, pretreatment with ACEA inhibited NGF-induced phosphorylation of AKT. Blocking PI3 kinase activity also attenuated the NGF-induced increase in the number of neurons that responded to capsaicin. Our results indicate that the analgesic effect of CB1 activation may in part be due to inhibition of NGF-induced sensitization of TRPV1 and also that the effect of CB1 activation is at least partly mediated by attenuation of NGF-induced increased PI3 signaling.

  20. Possible Therapeutic Doses of Cannabinoid Type 1 Receptor Antagonist Reverses Key Alterations in Fragile X Syndrome Mouse Model

    Directory of Open Access Journals (Sweden)

    Maria Gomis-González

    2016-08-01

    Full Text Available Fragile X syndrome (FXS is the most common monogenetic cause of intellectual disability. The cognitive deficits in the mouse model for this disorder, the Fragile X Mental Retardation 1 (Fmr1 knockout (KO mouse, have been restored by different pharmacological approaches, among those the blockade of cannabinoid type 1 (CB1 receptor. In this regard, our previous study showed that the CB1 receptor antagonist/inverse agonist rimonabant normalized a number of core features in the Fmr1 knockout mouse. Rimonabant was commercialized at high doses for its anti-obesity properties, and withdrawn from the market on the bases of mood-related adverse effects. In this study we show, by using electrophysiological approaches, that low dosages of rimonabant (0.1 mg/kg manage to normalize metabotropic glutamate receptor dependent long-term depression (mGluR-LTD. In addition, low doses of rimonabant (from 0.01 mg/kg equally normalized the cognitive deficit in the mouse model of FXS. These doses of rimonabant were from 30 to 300 times lower than those required to reduce body weight in rodents and to presumably produce adverse effects in humans. Furthermore, NESS0327, a CB1 receptor neutral antagonist, was also effective in preventing the novel object-recognition memory deficit in Fmr1 KO mice. These data further support targeting CB1 receptors as a relevant therapy for FXS.

  1. Possible Therapeutic Doses of Cannabinoid Type 1 Receptor Antagonist Reverses Key Alterations in Fragile X Syndrome Mouse Model

    Science.gov (United States)

    Gomis-González, Maria; Busquets-Garcia, Arnau; Matute, Carlos; Maldonado, Rafael; Mato, Susana; Ozaita, Andrés

    2016-01-01

    Fragile X syndrome (FXS) is the most common monogenetic cause of intellectual disability. The cognitive deficits in the mouse model for this disorder, the Fragile X Mental Retardation 1 (Fmr1) knockout (KO) mouse, have been restored by different pharmacological approaches, among those the blockade of cannabinoid type 1 (CB1) receptor. In this regard, our previous study showed that the CB1 receptor antagonist/inverse agonist rimonabant normalized a number of core features in the Fmr1 knockout mouse. Rimonabant was commercialized at high doses for its anti-obesity properties, and withdrawn from the market on the bases of mood-related adverse effects. In this study we show, by using electrophysiological approaches, that low dosages of rimonabant (0.1 mg/kg) manage to normalize metabotropic glutamate receptor dependent long-term depression (mGluR-LTD). In addition, low doses of rimonabant (from 0.01 mg/kg) equally normalized the cognitive deficit in the mouse model of FXS. These doses of rimonabant were from 30 to 300 times lower than those required to reduce body weight in rodents and to presumably produce adverse effects in humans. Furthermore, NESS0327, a CB1 receptor neutral antagonist, was also effective in preventing the novel object-recognition memory deficit in Fmr1 KO mice. These data further support targeting CB1 receptors as a relevant therapy for FXS. PMID:27589806

  2. Muscarinic Receptor Agonists and Antagonists

    Directory of Open Access Journals (Sweden)

    David R. Kelly

    2001-02-01

    Full Text Available A comprehensive review of pharmacological and medical aspects of the muscarinic class of acetylcholine agonists and antagonists is presented. The therapeutic benefits of achieving receptor subtype selectivity are outlined and applications in the treatment of Alzheimer’s disease are discussed. A selection of chemical routes are described, which illustrate contemporary methodology for the synthesis of chiral medicinal compounds (asymmetric synthesis, chiral pool, enzymes. Routes to bicyclic intrannular amines and intramolecular Diels-Alder reactions are highlighted.

  3. Localization of cannabinoid CB1 receptor mRNA using ribonucleotide probes: methods for double- and single-label in situ hybridization.

    Science.gov (United States)

    Hohmann, Andrea G

    2006-01-01

    This chapter presents a reliable, detailed method for performing double-label in situ hybridization (ISH) that has been validated for use in studies identifying the co-localization of cannabinoid CB1 receptor mRNA with other distinct species of mRNAs. This method permits simultaneous detection of two different species of mRNA within the same tissue section. Double-label ISH may be accomplished by hybridizing tissue sections with a combination of radiolabeled and digoxigenin-labeled RNA probes that are complementary to their target mRNAs. Single-label ISH may be accomplished by following the procedures described for use with radioisotopic probes (here [35S]-labeled) only. Silver grains derived from conventional emulsion autoradiography are used to detect the radiolabeled cRNA probe. An alkaline phosphatase-dependent chromogen reaction product is used to detect the nonisotopic (here, digoxigenin-labeled) cRNA probe. Necessary controls that are required to document the specificity of the labeling of the digoxigenin and radiolabeled probes are described. The methods detailed herein may be employed to detect even low levels of a target mRNA. These methods may be utilized to study co-localization and coregulation of expression of a particular gene within identified neurons in multiple systems.

  4. CB1基因的生物信息学分析%Bioinformatics Analysis on Cannabinoid Receptors 1 of Swine

    Institute of Scientific and Technical Information of China (English)

    魏星灿; 贾青; 陶隽; 胡慧艳

    2013-01-01

    运用生物信息学方法分析了猪和其他21个物种 CB1基因CDs序列的系统进化关系和猪C B1基因编码蛋白质的理化性质与结构。结果显示,C B1基因同源性较高,且在进化中受到纯化选择的作用。猪CB1蛋白为疏水性跨膜蛋白,包含472个氨基酸残基,不含信号肽。其一级结构含有23个磷酸化位点、6个糖基化位点;二级结构含有47.67%的α螺旋、39.62%的无规则卷曲、12.71%的延长链;三级结构由7个α螺旋和无规则卷曲组成。研究结果表明,C B1基因可能是哺乳动物的看家基因,7条相连的α螺旋结构是猪CB1的活性位点。%In the study ,the phylogenetic relationship of the coding sequences (CDS) of CB1 gene between swine and other 21 species ,and the physicochemical characters and structural properties of CB1-encoding protein in swine were analyzed with bioinformatics methods .The results showed that the homology of CB1 gene was high as purifying selection could exist in its evolution .The CB1 protein was a hydrophobic transmembrane protein consisting of 472 amino acid residues without signal peptide .The primary structure of the protein CB1 contained 23 phosphorylation sites and 6 glycosylation sites ,the secondary structure was made up of 47 .67% of α-helix , 39 .62% of random coil ,12 .71% of extended strand ,the tertiary structure was composed of 7α-heli-ces and random coil .The results indicate that CB1 maybe is a housekeeping gene of mammals and the 7 connected α-helices are active sites of CB1 in swine .

  5. Benzodiazepine receptor antagonists for hepatic encephalopathy

    DEFF Research Database (Denmark)

    Als-Nielsen, B; Gluud, L L; Gluud, C

    2004-01-01

    Hepatic encephalopathy may be associated with accumulation of substances that bind to a receptor-complex in the brain resulting in neural inhibition. Benzodiazepine receptor antagonists may have a beneficial effect on patients with hepatic encephalopathy.......Hepatic encephalopathy may be associated with accumulation of substances that bind to a receptor-complex in the brain resulting in neural inhibition. Benzodiazepine receptor antagonists may have a beneficial effect on patients with hepatic encephalopathy....

  6. A Theoretical Study of the Relationships between Electronic Structure and CB1 and CB2 Cannabinoid Receptor Binding Affinity in a Group of 1-Aryl-5-(1-H-pyrrol-1-yl-1-H-pyrazole-3-carboxamides

    Directory of Open Access Journals (Sweden)

    Francisco Salgado-Valdés

    2014-01-01

    Full Text Available We report the results of a search for model-based relationships between hCB1 and hCB2 receptor binding affinity and molecular structure for a group of 1-aryl-5-(1-H-pyrrol-1-yl-1-H-pyrazole-3-carboxamides. The wave functions and local atomic reactivity indices were obtained at the B3LYP/6-31G(d,p levels of theory with full geometry optimization. Interaction pharmacophores were generated for both receptors. The main conclusions of this work are as follows. (1 We obtained statistically significant equations relating the variation of hCB1 and hCB2 receptor binding affinities with the variation of definite sets of local atomic reactivity indices. (2 The interaction of the molecules with the hCB1 and hCB2 receptors seems to be highly complex and mainly orbital controlled. (3 The interaction mechanisms seem to be different for each type of receptor. This study, contrarily to the statistically backed ones, is able to provide a microscopic insight of the mechanisms involved in the binding process.

  7. Pharmacokinetic/pharmaco-dynamic modelling and simulation of the effects of different cannabinoid receptor type 1 antagonists on (9)-tetrahydrocannabinol challenge tests

    NARCIS (Netherlands)

    Guan, Zheng; Klumpers, Linda E.; Oyetayo, Olubukayo-Opeyemi; Heuberger, Jules; van Gerven, Joop M. A.; Stevens, Jasper

    2016-01-01

    Aim: The severe psychiatric side effects of cannabinoid receptor type 1 (CB1) antagonists hampered their wide development but this might be overcome by careful management of drug development with pharmacokinetic/pharmacodynamic (PK/PD) analyses. PK/PD models suitable for direct comparison of differe

  8. Pharmacokinetic/pharmaco-dynamic modelling and simulation of the effects of different cannabinoid receptor type 1 antagonists on (9)-tetrahydrocannabinol challenge tests

    NARCIS (Netherlands)

    Guan, Zheng; Klumpers, Linda E.; Oyetayo, Olubukayo-Opeyemi; Heuberger, Jules; van Gerven, Joop M. A.; Stevens, Jasper

    2016-01-01

    AimThe severe psychiatric side effects of cannabinoid receptor type 1 (CB1) antagonists hampered their wide development but this might be overcome by careful management of drug development with pharmacokinetic/pharmacodynamic (PK/PD) analyses. PK/PD models suitable for direct comparison of different

  9. Adolescent exposure to nicotine and/or the cannabinoid agonist CP 55,940 induces gender-dependent long-lasting memory impairments and changes in brain nicotinic and CB(1) cannabinoid receptors.

    Science.gov (United States)

    Mateos, B; Borcel, E; Loriga, R; Luesu, W; Bini, V; Llorente, R; Castelli, M P; Viveros, M-P

    2011-12-01

    We have analysed the long-term effects of adolescent (postnatal day 28-43) exposure of male and female rats to nicotine (NIC, 1.4 mg/kg/day) and/or the cannabinoid agonist CP 55,940 (CP, 0.4 mg/kg/day) on the following parameters measured in the adulthood: (1) the memory ability evaluated in the object location task (OL) and in the novel object test (NOT); (2) the anxiety-like behaviour in the elevated plus maze; and (3) nicotinic and CB(1) cannabinoid receptors in cingulated cortex and hippocampus. In the OL, all pharmacological treatments induced significant decreases in the DI of females, whereas no significant effects were found among males. In the NOT, NIC-treated females showed a significantly reduced DI, whereas the effect of the cannabinoid agonist (a decrease in the DI) was only significant in males. The anxiety-related behaviour was not changed by any drug. Both, nicotine and cannabinoid treatments induced a long-lasting increase in CB(1) receptor activity (CP-stimulated GTPγS binding) in male rats, and the nicotine treatment also induced a decrease in nicotinic receptor density in the prefrontal cortex of females. The results show gender-dependent harmful effects of both drugs and long-lasting changes in CB(1) and nicotinic receptors.

  10. O receptor canabinoide CB1 no córtex retrosplenial modula as fases de consolidação, reconsolidação e extinção da memória emocional

    OpenAIRE

    Ricardo Marcelo Sachser

    2015-01-01

    O receptor canabinoide CB1, altamente expresso em várias regiões do sistema límbico, possui um importante papel na regulação da plasticidade sináptica implicada nas diferentes fases da memória emocional. Em roedores, embora já estejam bem caracterizados os efeitos da manipulação farmacológica do receptor CB1 na amígdala, no hipocampo e no córtex pré-frontal medial sobre a modulação de memórias aversivas, sua função no córtex retrosplenial (RSC) permanece desconhecida. Neste trabalho, usando o...

  11. Evaluation of (Z)-2-((1-benzyl-1H-indol-3-yl)methylene)-quinuclidin-3-one analogues as novel, high affinity ligands for CB1 and CB2 cannabinoid receptors.

    Science.gov (United States)

    Madadi, Nikhil Reddy; Penthala, Narsimha Reddy; Brents, Lisa K; Ford, Benjamin M; Prather, Paul L; Crooks, Peter A

    2013-04-01

    A small library of N-benzyl indolequinuclidinone (IQD) analogs has been identified as a novel class of cannabinoid ligands. The affinity and selectivity of these IQDs for the two established cannabinoid receptor subtypes, CB1 and CB2, was evaluated. Compounds 8 (R=R(2)=H, R(1)=F) and 13 (R=COOCH3, R(1)=R(2)=H) exhibited high affinity for CB2 receptors with Ki values of 1.33 and 2.50 nM, respectively, and had lower affinities for the CB1 receptor (Ki values of 9.23 and 85.7 nM, respectively). Compound 13 had the highest selectivity of all the compounds examined, and represents a potent cannabinoid ligand with 34-times greater selectivity for CB2R over CB1R. These findings are significant for future drug development, given recent reports demonstrating beneficial use of cannabinoid ligands in a wide variety of human disease states including drug abuse, depression, schizophrenia, inflammation, chronic pain, obesity, osteoporosis and cancer.

  12. Receptors and Channels Targeted by Synthetic Cannabinoid Receptor Agonists and Antagonists

    OpenAIRE

    Pertwee, R. G.

    2010-01-01

    It is widely accepted that non-endogenous compounds that target CB1 and/or CB2 receptors possess therapeutic potential for the clinical management of an ever growing number of disorders. Just a few of these disorders are already treated with Δ9-tetrahydrocannabinol or nabilone, both CB1/CB2 receptor agonists, and there is now considerable interest in expanding the clinical applications of such agonists and also in exploiting CB2-selective agonists, peripherally restricted CB1/CB2 receptor ago...

  13. Anandamide capacitates bull spermatozoa through CB1 and TRPV1 activation.

    Directory of Open Access Journals (Sweden)

    María Gracia Gervasi

    Full Text Available Anandamide (AEA, a major endocannabinoid, binds to cannabinoid and vanilloid receptors (CB1, CB2 and TRPV1 and affects many reproductive functions. Nanomolar levels of anandamide are found in reproductive fluids including mid-cycle oviductal fluid. Previously, we found that R(+-methanandamide, an anandamide analogue, induces sperm releasing from bovine oviductal epithelium and the CB1 antagonist, SR141716A, reversed this effect. Since sperm detachment may be due to surface remodeling brought about by capacitation, the aim of this paper was to investigate whether anandamide at physiological concentrations could act as a capacitating agent in bull spermatozoa. We demonstrated that at nanomolar concentrations R(+-methanandamide or anandamide induced bull sperm capacitation, whereas SR141716A and capsazepine (a TRPV1 antagonist inhibited this induction. Previous studies indicate that mammalian spermatozoa possess the enzymatic machinery to produce and degrade their own AEA via the actions of the AEA-synthesizing phospholipase D and the fatty acid amide hydrolase (FAAH respectively. Our results indicated that, URB597, a potent inhibitor of the FAAH, produced effects on bovine sperm capacitation similar to those elicited by exogenous AEA suggesting that this process is normally regulated by an endogenous tone. We also investigated whether anandamide is involved in bovine heparin-capacitated spermatozoa, since heparin is a known capacitating agent of bovine sperm. When the spermatozoa were incubated in the presence of R(+-methanandamide and heparin, the percentage of capacitated spermatozoa was similar to that in the presence of R(+-methanandamide alone. The pre-incubation with CB1 or TRPV1 antagonists inhibited heparin-induced sperm capacitation; moreover the activity of FAAH was 30% lower in heparin-capacitated spermatozoa as compared to control conditions. This suggests that heparin may increase endogenous anandamide levels. Our findings indicate

  14. Effects of the cannabinoid CB1 receptor antagonist rimonabant on distinct measures of impulsive behavior in rats

    NARCIS (Netherlands)

    Pattij, Tommy; Janssen, Mieke; Schepers, Inga; González-Cuevas, Gustavo; Vries, de Taco; Schoffelmeer, Anton

    2007-01-01

    Rationale Pathological impulsivity is a prominent feature in several psychiatric disorders, but detailed understanding of the specific neuronal processes underlying impulsive behavior is as yet lacking. Objectives As recent findings have suggested involvement of the brain cannabinoid syste

  15. CB1大麻素受体激动剂抑制基质金属蛋白酶参与脊髓损伤后血-脊髓屏障通透性调节%Involvement of CB1 cannabinoid receptor agonist in the permeability of blood spinal cord barrier after acute spinal cord in-jury in rat model

    Institute of Scientific and Technical Information of China (English)

    董宝铁; 李泓; 费良健; 王岩峰

    2015-01-01

    目的:探讨CB1大麻素受体激动剂在大鼠脊髓损伤后对血-脊髓屏障通透性调节的作用。方法将150只雌性SD大鼠随机分为假手术组( Sham组)、脊髓损伤组( SCI组)和CB1激动剂处理组( ACEA组)。采用改良Allen法建立T9脊髓损伤实验动物模型。 Sham组仅行T9椎板切除术,SCI组和ACEA组以30 g·cm致伤力制作模型。 ACEA组建模成功后,每日腹腔给药ACEA 3mg/(kg·d);Sham组和SCI组以生理盐水代替。建模术后12、24、72 h分时段处死动物,取T8~T10脊髓节段,Evans蓝含量测定法检测SCI后血-脊髓屏障通透性变化,定量RT-PCR法检测脊髓组织基质金属蛋白酶9(MMP9)表达水平。结果 Sham组脊髓通透性无改变,脊髓组织中无Evans蓝渗入,ACEA组Evans蓝通过血-脊髓屏障渗漏至脊髓,但渗漏量明显低于SCI组。 ACEA组MMP9表达水平显著低于Sci组。结论 CB1受体激动剂ACEA能降低Allen′s大鼠脊髓损伤模型血-脊髓屏障的破坏,其作用机制可能与MMP9的表达下调相关。%Objective To investigate whether the CB1 cannabinoid receptor agonist has regulating effect on permeability of blood spi-nal cord barrier( BSCB) after spinal cord injury( SCI) in rat model. Methods Totally 150 female SD rats were randomly divided into three groups,including sham operation group(Sham group),spinal cord injury group(SCI group)and ACEA treatment group(ACEA group). Modified Allen′s method was carried out at T9 level spinal segment for SCI group and ACEA group to induce acute SCI. While Sham group only underwent laminectomy. Rats in ACEA group were treated with ACEA 3 mg/( kg·d) after surgery until killed. After modeling,the animals were sacrificed at 12,24 and 72 hours,and the level of permeability for BSC was detected by Evans blue assay at T8-T10. The expression level of MMP9 was detected by quantitative RT-PCR method. Results There was no change in the permeabil-ity of BSCB for the Sham group,no Evans blue in the

  16. Involvement of ERK1/2, cPLA2 and NF-κB in microglia suppression by cannabinoid receptor agonists and antagonists.

    Science.gov (United States)

    Ribeiro, Rachel; Wen, Jie; Li, Shihe; Zhang, Yumin

    2013-01-01

    Cannabinoids have been consistently shown to suppress microglia activation and the release of cytotoxic factors including nitric oxide, superoxide and proinflammatory cytokines. However, the underlying molecular mechanisms and whether the action of cannabinoids is coupled to the activation of cannabinoid type 1 (CB1) and type 2 (CB2) receptors are still poorly defined. In this study we observed that the CB1 and CB2 receptor non-selective or selective agonists dramatically attenuate iNOS induction and ROS generation in LPS-activated microglia. These effects are due to their reduction of phosphorylation of extracellular signal regulated kinase 1/2 (ERK1/2), cytosolic phospholipase A (cPLA) and activation of NF-κB. Surprisingly, instead of reversing the effect of the respective CB1 and CB2 receptor agonists, the antagonists also suppress iNOS induction and ROS generation in activated microglia by similar mechanisms. Taken together, these results indicate that both cannabinoid receptor agonists and antagonists might suppress microglia activation by CB1 and CB2 receptor independent mechanisms, and provide a new insight into the mechanisms of microglia inhibition by cannabinoids.

  17. CB1 receptor agonist WIN55212-2 improves motor complications in Parkinson's disease%CB1受体激动剂WIN55212-2改善帕金森病运动并发症的实验研究

    Institute of Scientific and Technical Information of China (English)

    马雅萍; 宋璐; 刘振国; 巴茂文; 卞雷斯

    2011-01-01

    目的 探讨CB1受体激动剂WIN55212-2对左旋多巴诱发的运动并发症的行为学及细胞学作用.方法通过6-OHDA立体定向注射至大鼠右侧前脑内侧束建立PD动物模型,成功的PD大鼠模型分别接受左旋多巴/苄丝肼(50mg/kg加12.5mg/kg苄丝肼,每天2次)+溶剂、左旋多巴/苄丝肼+WIN55212-2(1 mg/kg)腹腔注射,共持续21d.评估用药后大鼠的旋转反应时间、剂峰旋转圈数变化和关期发生率;采用Western blot方法检测纹状体信号转导蛋白DARPP-32(Thr75)和ERK1/2 (Thr202/Tyr204)的磷酸化表达.结果长期联合应用WIN55212-2和左旋多巴,缓解了左旋多巴单独用药所致的PD大鼠旋转反应时间缩短、剂峰旋转圈数增加的趋势,并明显降低关期发生频率.WIN55212-2与左旋多巴合用显著降低了纹状体内DARPP-32(Thr75)的磷酸化;但未使ERK1/2磷酸化表达降低至对照组水平.结论激动CB1受体可能有益于预防帕金森病运动并发症.%Objective To investigate cellular and behavioural effects of CB1 receptor agonist WIN55212-2 in a rat model of levodopa-induced motor complications. Methods The hemi-Parkinsonian rat model was produced by stereotaxically injecting 6-OHDA to right medial forebrain bundle( MFB). Animals were intraperitoneally treated with levodopa/ benserazide (50mg/kg levodopa plus 12.5mg/kg benserazide) or WIN55212-2( lmg/kg) + levodopa/benserazide twice a day for 21 days. Rotational duration,peak rotation and the frequency of failures to L-dopa were estimated. After sacrificed,the phosphorylation of dopamine and cAMP- regulated phosphoprotein of Mr 32,000( DARPP-32) at Thr75 site and extracellular signal-regulated kinase (ERK) at Thr202 and Tyr204 site was observed by Western blot. Results W1N55212-2 plus L-dopa treatment prolonged the duration of the motor response and reduced peak turning. WIN55212-2 plus L-dopa also decreased the frequency of failures to L-dopa. The long-term use of L-dopa reduced the

  18. Modulation of pilocarpine-induced seizures by cannabinoid receptor 1.

    Directory of Open Access Journals (Sweden)

    Rebecca L Kow

    Full Text Available Administration of the muscarinic agonist pilocarpine is commonly used to induce seizures in rodents for the study of epilepsy. Activation of muscarinic receptors has been previously shown to increase the production of endocannabinoids in the brain. Endocannabinoids act at the cannabinoid CB1 receptors to reduce neurotransmitter release and the severity of seizures in several models of epilepsy. In this study, we determined the effect of CB1 receptor activity on the induction in mice of seizures by pilocarpine. We found that decreased activation of the CB1 receptor, either through genetic deletion of the receptor or treatment with a CB1 antagonist, increased pilocarpine seizure severity without modifying seizure-induced cell proliferation and cell death. These results indicate that endocannabinoids act at the CB1 receptor to modulate the severity of pilocarpine-induced seizures. Administration of a CB1 agonist produced characteristic CB1-dependent behavioral responses, but did not affect pilocarpine seizure severity. A possible explanation for the lack of effect of CB1 agonist administration on pilocarpine seizures, despite the effects of CB1 antagonist administration and CB1 gene deletion, is that muscarinic receptor-stimulated endocannabinoid production is acting maximally at CB1 receptors to modulate sensitivity to pilocarpine seizures.

  19. Pharmacological blockade of either, cannabinoid CB1 or CB2 receptors, prevents both cocaine-induced conditioned locomotion and cocaine-induced reduction of cell proliferation in the hippocampus of adult male rats.

    Directory of Open Access Journals (Sweden)

    EDUARDO eBLANCO-CALVO

    2014-01-01

    Full Text Available Addiction to major drugs of abuse such as cocaine has been recently linked to alterations on adult neurogenesis in the hippocampus. The endogenous cannabinoid system modulated this proliferative response since pharmacological activation/blockade of cannabinoid CB1 and CB2 receptors by modulating not only neurogenesis but also cell death in the brain. In the present study, we evaluated whether the endogenous cannabinoid system affects cocaine-induced alterations in cell proliferation . To this end we examined if pharmacological blockade of either CB1 (Rimonabant, 3 mg/kg or CB2 receptors (AM630, 3 mg/kg affects cell proliferation (labeled with BrdU, found in the subventricular zone (SVZ of the lateral ventricles and the dentate subgranular zone (SGZ. In addition, we measured cell apoptosis (monitored by the expression of cleaved caspase-3 and glial activation ( by analizing the expression of GFAP and Iba-1 in the striatum and hippocampus, during acute or repeated (4 days cocaine administration (20 mg/kg. Results showed that acute cocaine decreased the number of BrdU+ cells in SVZ and SGZ. In contrast, repeated cocaine reduced the number of BrdU+ cells in SVZ only. Both acute and repeated cocaine increased the number of cleaved caspase-3+, GFAP+ and Iba1+ cells in the hippocampus, an effect counteracted by AM630 or Rimonabant that increased the number of BrdU+, GFAP+ and Iba1+ cells in the hippocampus. These results indicate that changes on neurogenic, apoptotic and gliosis processes, which were produced as a consequence of repeated cocaine administration, were normalized by the pharmacological blockade of CB1 and CB2. The restoring effects of cannabinoid receptor blockade on hippocampal cell proliferation were associated with a prevention of the induction of conditioned locomotion, but not of cocaine-induced sensitization.

  20. Pharmacological blockade of either cannabinoid CB1 or CB2 receptors prevents both cocaine-induced conditioned locomotion and cocaine-induced reduction of cell proliferation in the hippocampus of adult male rat.

    Science.gov (United States)

    Blanco-Calvo, Eduardo; Rivera, Patricia; Arrabal, Sergio; Vargas, Antonio; Pavón, Francisco Javier; Serrano, Antonia; Castilla-Ortega, Estela; Galeano, Pablo; Rubio, Leticia; Suárez, Juan; Rodriguez de Fonseca, Fernando

    2014-01-01

    Addiction to major drugs of abuse, such as cocaine, has recently been linked to alterations in adult neurogenesis in the hippocampus. The endogenous cannabinoid system modulates this proliferative response as demonstrated by the finding that pharmacological activation/blockade of cannabinoid CB1 and CB2 receptors not only modulates neurogenesis but also modulates cell death in the brain. In the present study, we evaluated whether the endogenous cannabinoid system affects cocaine-induced alterations in cell proliferation. To this end, we examined whether pharmacological blockade of either CB1 (Rimonabant, 3 mg/kg) or CB2 receptors (AM630, 3 mg/kg) would affect cell proliferation [the cells were labeled with 5-bromo-2'-deoxyuridine (BrdU)] in the subventricular zone (SVZ) of the lateral ventricle and the dentate subgranular zone (SGZ). Additionally, we measured cell apoptosis (as monitored by the expression of cleaved caspase-3) and glial activation [by analyzing the expression of glial fibrillary acidic protein (GFAP) and Iba-1] in the striatum and hippocampus during acute and repeated (4 days) cocaine administration (20 mg/kg). The results showed that acute cocaine exposure decreased the number of BrdU-immunoreactive (ir) cells in the SVZ and SGZ. In contrast, repeated cocaine exposure reduced the number of BrdU-ir cells only in the SVZ. Both acute and repeated cocaine exposure increased the number of cleaved caspase-3-, GFAP- and Iba1-ir cells in the hippocampus, and this effect was counteracted by AM630 or Rimonabant, which increased the number of BrdU-, GFAP-, and Iba1-ir cells in the hippocampus. These results indicate that the changes in neurogenic, apoptotic and gliotic processes that were produced by repeated cocaine administration were normalized by pharmacological blockade of CB1 and CB2. The restorative effects of cannabinoid receptor blockade on hippocampal cell proliferation were associated with the prevention of the induction of conditioned locomotion

  1. Effects of Repeated Electroacupuncture on Gene Expression of Cannabinoid Receptor-1 and Dopamine 1 Receptor in Nucleus Accumbens-Caudate Nucleus Region in Inflammatory-pain Rats%反复电针对佐剂性关节炎大鼠伏隔核-尾状核区大麻素CB1受体与多巴胺Dl受体基因表达的影响

    Institute of Scientific and Technical Information of China (English)

    寿鉴; 赵颖倩; 徐鸣曙; 葛林宝

    2011-01-01

    Objective To observe the effect of repeated electroacupuncture (EA) on the expression of cannabinoid receptor-1 (CB 1 ) mRNA and dopamine 1 receptor (D 1 ) mRNA in Nucleus Accumbens (NAC)-Caudate Nucleus (CN) region in inflammatory-pain rats, so as to study its underlying mechanism in analgesia. Methods A total of 30 SD rats were randomized into normal control, model, EA, EA + AM 251 and WIN 552 12-2 groups, with 6 cases in each group. EA (2 Hz/100 Hz, 1 - 3 mA)was applied to "Zusanli"(ST 36) and "Kunlun"(BL 60) for 30 min, once every other day, and 4 sessions all together. Arthritis model was established by injection of Freund's complete adjuvant 0.05 mL in the rat's left ankle. Thermal pain threshold (paw withdrawal latency, PWL) was detected before and after modeling and after repeated EA and/or intraperitoneal injection of AM 251 (an inverse antagonist at the CB 1 cannabinoid receptor, 0. 1 mg/1 00 g) and WIN 55212-2 (a potent cannabinoid receptor agonist, 0.2 mg/100 g). The expression of CB 1 receptor mRNA and D 1 receptor mRNA in the NAC-CN region was measured by real time fluorescence quantitative-polymerase chain reaction. Results Compared with the control group, the pain threshold values of the model group was decreased significantly (P<0.01). In comparison with the model group, the pain threshold values of the EA group and WIN 55212-2 group were increased considerably on day 10 (P<0.01). No significant differences were found between the EA+AM 251 and model groups and between the EA and WIN 55212-2 groups in PWL after the treatment (P>0.05).Compared with the control group, both CB 1 R mRNA and D 1 R mRNA expression levels in the model group were increased slightly, while in comparison with the model group and EA+ AM 251 group, CB 1 R mRNA and D 1 R mRNA expression levels in the EAgroup and WIN 55212-2 group were upregulated obviously. No significant differences were found between the EA+ AM 251 and model groups and between the EA and WIN 55212

  2. Why are mineralocorticoid receptor antagonists cardioprotective?

    NARCIS (Netherlands)

    W. Chai (Wenxia); A.H.J. Danser (Jan)

    2006-01-01

    textabstractTwo clinical trials, the Randomized ALdosterone Evaluation Study (RALES) and the EPlerenone HEart failure and SUrvival Study (EPHESUS), have recently shown that mineralocorticoid receptor (MR) antagonists reduce mortality in patients with heart failure on top of ACE inhibition. This effe

  3. Endocannabinoid System Contributes to Liver Injury and Inflammation by Activation of Bone Marrow-Derived Monocytes/Macrophages in a CB1-Dependent Manner.

    Science.gov (United States)

    Mai, Ping; Yang, Le; Tian, Lei; Wang, Lin; Jia, Shuangshuang; Zhang, Yuanyuan; Liu, Xin; Yang, Lin; Li, Liying

    2015-10-01

    Hepatic injury undergoes significant increases in endocannabinoidsand infiltrations of macrophages, yet the concrete mechanisms of changes in endocannabinoids and the functions of macrophage-expressed cannabinoid receptors (CBs) are unclear. Biosynthetic and degradative enzymes of endocannabinoids revealed a significant change in human fibrotic liver. Meanwhile, we showed dynamic changes of these enzymes and CBs (CB1 and CB2) from 1 to 56 d in carbon tetrachloride-induced murine liver injury. Biosynthetic enzymes (N-acylphosphatidyl-ethanolamine selective phospholipase D and diacylglycerol lipase-α) and CBs were markedly increased, whereas degradative enzymes (fatty acid amidohydrolase and monoacylglycerol lipase) were downregulated. Moreover, these enzymes intimately correlated with the fibrosis parameter [procollagen α1(III)]. Bone marrow-derived monocytes/macrophages (BMM) expressed CBs. Interestingly, CB1 but not CB2 mediated BMM migration through a Boyden chambers assay, and the effect depended on the G(α)i/o/RhoA/ROCK signaling pathway. ICR mice were lethally irradiated and received BM transplants from enhanced GFP transgenic mice. Four weeks later, mice of BM reconstruction were subjected to carbon tetrachloride-induced liver injury. In the chimeric murine model, we found that blockade of CB1 by administration of a CB1 antagonist inhibited the recruitment of BMM into injured liver using immunofluorescence staining and FACS, but it did not have effects on migration of T cells and dendritic cells without CB1 expression. Furthermore, activation of CB1 enhanced cytokine expression of BMM. In vivo, inhibition of CB1 attenuated the inflammatory cytokine level through real-time RT-PCR and cytometric bead array, ameliorating hepatic inflammation and fibrosis. In this study, we identify inactivation of BMM-expressed CB1 as a therapeutic strategy for reducing hepatic inflammation and fibrosis.

  4. GABAA receptor partial agonists and antagonists

    DEFF Research Database (Denmark)

    Krall, Jacob; Balle, Thomas; Krogsgaard-Larsen, Niels;

    2015-01-01

    A high degree of structural heterogeneity of the GABAA receptors (GABAARs) has been revealed and is reflected in multiple receptor subtypes. The subunit composition of GABAAR subtypes is believed to determine their localization relative to the synapses and adapt their functional properties...... to the local temporal pattern of GABA impact, enabling phasic or tonic inhibition. Specific GABAAR antagonists are essential tools for physiological and pharmacological elucidation of the different type of GABAAR inhibition. However, distinct selectivity among the receptor subtypes (populations) has been shown...

  5. EFFECT OF ANGIOTENSIN II RECEPTOR ANTAGONIST AND ENDOTHELIN RECEPTOR ANTAGONIST ON NITROGLYCERIN TOLERANCE IN RATS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective. To investigate whether angiotensin II receptor antagonist and endothelin receptor antagonist can improve the nitroglycerin (Nit) tolerance in vivo. Methods. Twenty-four rats were divided into 4 groups (n=6,each): Control group, Nitroglycerin (Nit) group, Nit+ bosentan group and Nit+ losartan group. Nitroglycerin tolerance was induced by 2-day treatment of nitroglycerin patch (0.05 mg/h). AngiotensinⅡ receptor antagonist losartan ( 10 mg· kg- 1· d- 1 ) and endothelin receptor antagonist bosentan ( 100 mg· kg- 1· d- 1 ) were given by gavage for 2 days respectively. Results. The least hypotensive response to sodium nitroprusside (SNP) was observed in Nit group . The effective percentages of hypotensive response to SNP were increased in both Nit+ losartan group and Nit+ bosentan group compared with Nit group [(31.95± 4.45 ) % vs (21.00± 3.69 ) % , P Conclusion. Endothelin receptor antagonist and angiotensin Ⅱ receptor antagonist could prevent against the Nit tolerance .

  6. Pharmacological blockade of either cannabinoid CB1 or CB2 receptors prevents both cocaine-induced conditioned locomotion and cocaine-induced reduction of cell proliferation in the hippocampus of adult male rat

    Science.gov (United States)

    Blanco-Calvo, Eduardo; Rivera, Patricia; Arrabal, Sergio; Vargas, Antonio; Pavón, Francisco Javier; Serrano, Antonia; Castilla-Ortega, Estela; Galeano, Pablo; Rubio, Leticia; Suárez, Juan; Rodriguez de Fonseca, Fernando

    2014-01-01

    Addiction to major drugs of abuse, such as cocaine, has recently been linked to alterations in adult neurogenesis in the hippocampus. The endogenous cannabinoid system modulates this proliferative response as demonstrated by the finding that pharmacological activation/blockade of cannabinoid CB1 and CB2 receptors not only modulates neurogenesis but also modulates cell death in the brain. In the present study, we evaluated whether the endogenous cannabinoid system affects cocaine-induced alterations in cell proliferation. To this end, we examined whether pharmacological blockade of either CB1 (Rimonabant, 3 mg/kg) or CB2 receptors (AM630, 3 mg/kg) would affect cell proliferation [the cells were labeled with 5-bromo-2′-deoxyuridine (BrdU)] in the subventricular zone (SVZ) of the lateral ventricle and the dentate subgranular zone (SGZ). Additionally, we measured cell apoptosis (as monitored by the expression of cleaved caspase-3) and glial activation [by analyzing the expression of glial fibrillary acidic protein (GFAP) and Iba-1] in the striatum and hippocampus during acute and repeated (4 days) cocaine administration (20 mg/kg). The results showed that acute cocaine exposure decreased the number of BrdU-immunoreactive (ir) cells in the SVZ and SGZ. In contrast, repeated cocaine exposure reduced the number of BrdU-ir cells only in the SVZ. Both acute and repeated cocaine exposure increased the number of cleaved caspase-3-, GFAP- and Iba1-ir cells in the hippocampus, and this effect was counteracted by AM630 or Rimonabant, which increased the number of BrdU-, GFAP-, and Iba1-ir cells in the hippocampus. These results indicate that the changes in neurogenic, apoptotic and gliotic processes that were produced by repeated cocaine administration were normalized by pharmacological blockade of CB1 and CB2. The restorative effects of cannabinoid receptor blockade on hippocampal cell proliferation were associated with the prevention of the induction of conditioned

  7. Orchestrated activation of mGluR5 and CB1 promotes neuroprotection.

    Science.gov (United States)

    Batista, Edleusa M L; Doria, Juliana G; Ferreira-Vieira, Talita H; Alves-Silva, Juliana; Ferguson, Stephen S G; Moreira, Fabricio A; Ribeiro, Fabiola M

    2016-08-20

    The metabotropic glutamate receptor 5 (mGluR5) and the cannabinoid receptor 1 (CB1) exhibit a functional interaction, as CB1 regulates pre-synaptic glutamate release and mGluR5 activation increases endocannabinoid synthesis at the post-synaptic site. Since both mGluR5 and CB1 promote neuroprotection, we delineated experiments to investigate a possible link between CB1 and mGluR5 activation in the induction of neuroprotection using primary cultured corticostriatal neurons. We find that either the pharmacological blockade or the genetic ablation of either mGluR5 or CB1 can abrogate both CB1- and mGluR5-mediated neuroprotection against glutamate insult. Interestingly, decreased glutamate release and diminished intracellular Ca(2+) do not appear to play a role in CB1 and mGluR5-mediated neuroprotection. Rather, these two receptors work cooperatively to trigger the activation of cell signaling pathways to promote neuronal survival, which involves MEK/ERK1/2 and PI3K/AKT activation. Interestingly, although mGluR5 activation protects postsynaptic terminals and CB1 the presynaptic site, intact signaling of both receptors is required to effectively promote neuronal survival. In conclusion, mGluR5 and CB1 act in concert to activate neuroprotective cell signaling pathways and promote neuronal survival.

  8. ETA-receptor antagonists or allosteric modulators?

    DEFF Research Database (Denmark)

    De Mey, Jo G R; Compeer, Matthijs G; Lemkens, Pieter

    2011-01-01

    The paracrine signaling peptide endothelin-1 (ET1) is involved in cardiovascular diseases, cancer and chronic pain. It acts on class A G-protein-coupled receptors (GPCRs) but displays atypical pharmacology. It binds tightly to ET receptor type A (ET(A)) and causes long-lasting effects. In resista......The paracrine signaling peptide endothelin-1 (ET1) is involved in cardiovascular diseases, cancer and chronic pain. It acts on class A G-protein-coupled receptors (GPCRs) but displays atypical pharmacology. It binds tightly to ET receptor type A (ET(A)) and causes long-lasting effects....... In resistance arteries, the long-lasting contractile effects can only be partly and reversibly relaxed by low-molecular-weight ET(A) antagonists (ERAs). However, the neuropeptide calcitonin-gene-related peptide selectively terminates binding of ET1 to ET(A). We propose that ET1 binds polyvalently to ET(A......) and that ERAs and the physiological antagonist allosterically reduce ET(A) functions. Combining the two-state model and the two-domain model of GPCR function and considering receptor activation beyond agonist binding might lead to better anti-endothelinergic drugs. Future studies could lead to compounds...

  9. Mineralocorticoid and glucocorticoid receptor antagonists in animal models of anxiety

    NARCIS (Netherlands)

    Korte, SM; KorteBouws, GAH; Koob, GF; DeKloet, ER; Bohus, B

    1996-01-01

    The behavioral effects of intracerebroventricular (ICV) administration of a specific mineralocorticoid receptor (MR) antagonist [RU28318 (10-50 ng/2 mu l)], a glucocorticoid receptor (GR) antagonist [RU38486 (1-50 ng/2 mu l)], or both antagonists (50 ng/2 mu l), were studied in two different animal

  10. Presynaptic cannabinoid CB1 receptors are involved in the inhibition of the neurogenic vasopressor response during septic shock in pithed rats

    OpenAIRE

    Godlewski, Grzegorz; Malinowska, Barbara; Schlicker, Eberhard

    2004-01-01

    Our study was undertaken to investigate whether bacterial endotoxin/lipopolysaccharide (LPS) affects the neurogenic vasopressor response in rats in vivo by presynaptic mechanisms and, if so, to characterize the type of presynaptic receptor(s) operating in the initial phase of septic shock.In pithed and vagotomized rats treated with pancuronium, electrical stimulation (ES) (1 Hz, 1 ms, 50 V for 10 s) of the preganglionic sympathetic nerve fibers or intravenous bolus injection of noradrenaline ...

  11. Human lung-resident macrophages express CB1 and CB2 receptors whose activation inhibits the release of angiogenic and lymphangiogenic factors.

    Science.gov (United States)

    Staiano, Rosaria I; Loffredo, Stefania; Borriello, Francesco; Iannotti, Fabio Arturo; Piscitelli, Fabiana; Orlando, Pierangelo; Secondo, Agnese; Granata, Francescopaolo; Lepore, Maria Teresa; Fiorelli, Alfonso; Varricchi, Gilda; Santini, Mario; Triggiani, Massimo; Di Marzo, Vincenzo; Marone, Gianni

    2016-04-01

    Macrophages are pivotal effector cells in immune responses and tissue remodeling by producing a wide spectrum of mediators, including angiogenic and lymphangiogenic factors. Activation of cannabinoid receptor types 1 and 2 has been suggested as a new strategy to modulate angiogenesis in vitro and in vivo. We investigated whether human lung-resident macrophages express a complete endocannabinoid system by assessing their production of endocannabinoids and expression of cannabinoid receptors. Unstimulated human lung macrophage produce 2-arachidonoylglycerol,N-arachidonoyl-ethanolamine,N-palmitoyl-ethanolamine, and N-oleoyl-ethanolamine. On LPS stimulation, human lung macrophages selectively synthesize 2-arachidonoylglycerol in a calcium-dependent manner. Human lung macrophages express cannabinoid receptor types 1 and 2, and their activation induces ERK1/2 phosphorylation and reactive oxygen species generation. Cannabinoid receptor activation by the specific synthetic agonists ACEA and JWH-133 (but not the endogenous agonist 2-arachidonoylglycerol) markedly inhibits LPS-induced production of vascular endothelial growth factor-A, vascular endothelial growth factor-C, and angiopoietins and modestly affects IL-6 secretion. No significant modulation of TNF-α or IL-8/CXCL8 release was observed. The production of vascular endothelial growth factor-A by human monocyte-derived macrophages is not modulated by activation of cannabinoid receptor types 1 and 2. Given the prominent role of macrophage-assisted vascular remodeling in many tumors, we identified the expression of cannabinoid receptors in lung cancer-associated macrophages. Our results demonstrate that cannabinoid receptor activation selectively inhibits the release of angiogenic and lymphangiogenic factors from human lung macrophage but not from monocyte-derived macrophages. Activation of cannabinoid receptors on tissue-resident macrophages might be a novel strategy to modulate macrophage-assisted vascular remodeling

  12. EFFECTS OF REPEATED ELECTRO-ACUPUNCTURE ON PROTEIN AND GENE EXPRESSION OF CANNABINOID CB1 RECEPTOR IN NUCLEUS ACCUMBENS AND CAUDATE NUCLEUS IN INFLAMMATORY-PAIN RATS%反复电针对佐剂性关节炎大鼠伏膈核尾状核内大麻素CB1受体表达的影响

    Institute of Scientific and Technical Information of China (English)

    寿崟; 赵颖倩; 徐鸣曙; 葛林宝

    2010-01-01

    目的:研究大麻素CB1受体是否参与电针镇痛.方法:以完全弗氏佐剂造成AA大鼠模型,在电针治疗四次后以大麻素CB1受体拮抗剂AM251进行干预,检测各组大鼠缩爪反射潜伏期(PWL)的变化,并应用实时荧光定量PCR(FQ-PCR)和Western blot检测伏膈核、尾状核内CB1受体mRNA和蛋白质表达情况.结果:(1)电针治疗后大鼠PWL延长,电针+AM251组的电针镇痛效果显著弱于电针组(P<0.01);(2)电针+AM251组较电针组大鼠伏膈核、尾状核内CB1受体mRNA表达水平显著降低(P<0.01),但与假模型组和模型组比较,无显著性差异(P>0.05).(3)Western blot结果与FQ-PCR结果一致:电针+AM251组较电针组大鼠伏膈核、尾状核内CB1受体蛋白质表达水平显著降低(P<0.01).但与假模型组和模型组比较,无显著性差异(P>0.05).结论:AM251能够翻转电针后大鼠伏膈核、尾状核内CB1受体的高表达,减弱电针镇痛作用,提示CB1受体可能参与电针镇痛作用.

  13. EFFECT OF ANGIOTENSIN II RECEPTOR ANTAGONIST AND ENDOTHELIN RECEPTOR ANTAGONIST ON NITROGLYCERIN TOLERANCE IN RATS

    Institute of Scientific and Technical Information of China (English)

    张建梅; 陈永红; 王晓红; 唐朝枢

    2001-01-01

    Objective. To investigate whether angiotensin II receptor antagonist and endothelin receptor antagonist can improve the nitroglycerin (Nit) tolerance in vivo. Methods. Twenty-four rats were divided into 4 groups (n =6, each): Control group, Nitroglycerin (Nit) group, Nit + bosentan group and Nit + losartan group. Nitroglycerin tolerance was induced by 2-day treatment ofnitroglycerin patch (0. 05mg/h). Angiotensin I1 receptor antagonist losartan (10mg ·kg-1·d-1) and endothe-lin receptor antagonist bosentan ( 100 mg·kg-1· d-1 ) were given by gavage for 2 days respectively. Results. The least hypotensive response to sodium nitroprusside (SNP) was observed in Nit group. The effec-tive percentages of hypotensive response to SNP were increased in both Nit + losartan group and Nit + bosentangroup compared with Nit group [(31.95±4.45) % vs (21.00±3.69) %, P <0.01and (33. 18±6. 16)% vs (21.00±3.69 ) %, P < 0. 01 , respectivelyl. The maximal vessel relaxation induced by SNP was thesame in 4 different groups but the highest EC50 (concentration which produces 50% of the maximal response toSNP) was found in tolerant group[ (34 ±10) nmol/L, P < 0. 01 ]. The ET-1 amounts in plasma and vasculartissue were markedly increased by 54% and 60% in Nit group compared with those in control group( P<0. 01). The ET-1 amounts in plasma and vascular tissue were decreased by 30% and 37% in Nit + losartangroup compared with those in Nit group ( P < 0.01 ). Conclusion. Endothelin receptor antagonist and angiotensin Ⅱ receptor antagonist could prevent against the Nit tolerance.

  14. Role of systemic endocannabinoid CB-1 receptor antagonism in the acquisition and expression of fructose-conditioned flavor–flavor preferences in rats

    OpenAIRE

    Miner, Patricia; Abayev, Yana; Kandova, Ester; Gerges, Meri; Styler, Esther; Wapniak, Rachel; Touzani, Khalid; Sclafani, Anthony; Bodnar, Richard J.

    2008-01-01

    Rats learn to prefer a flavor mixed into a fructose–saccharin solution over a different flavor mixed into a saccharin-only solution which is considered to be a form of flavor–flavor conditioning. Fructose-conditioned flavor preferences are impaired by systemic dopamine D1 and to a lesser degree, D2 receptor antagonism as well as by NMDA, but not opioid, receptor antagonism. Given the emerging role of the endocannabinoid system in mediating hedonically-driven food intake, the present study exa...

  15. Cell type-specific long-term plasticity at glutamatergic synapses onto hippocampal interneurons expressing either parvalbumin or CB1 cannabinoid receptor.

    Science.gov (United States)

    Nissen, Wiebke; Szabo, Andras; Somogyi, Jozsef; Somogyi, Peter; Lamsa, Karri P

    2010-01-27

    Different GABAergic interneuron types have specific roles in hippocampal function, and anatomical as well as physiological features vary greatly between interneuron classes. Long-term plasticity of interneurons has mostly been studied in unidentified GABAergic cells and is known to be very heterogeneous. Here we tested whether cell type-specific plasticity properties in distinct GABAergic interneuron types might underlie this heterogeneity. We show that long-term potentiation (LTP) and depression (LTD), two common forms of synaptic plasticity, are expressed in a highly cell type-specific manner at glutamatergic synapses onto hippocampal GABAergic neurons. Both LTP and LTD are generated in interneurons expressing parvalbumin (PV+), whereas interneurons with similar axon distributions but expressing cannabinoid receptor-1 show no lasting plasticity in response to the same protocol. In addition, LTP or LTD occurs in PV+ interneurons with different efferent target domains. Perisomatic-targeting PV+ basket and axo-axonic interneurons express LTP, whereas glutamatergic synapses onto PV+ bistratified cells display LTD. Both LTP and LTD are pathway specific, independent of NMDA receptors, and occur at synapses with calcium-permeable (CP) AMPA receptors. Plasticity in interneurons with CP-AMPA receptors strongly modulates disynaptic GABAergic transmission onto CA1 pyramidal cells. We propose that long-term plasticity adjusts the synaptic strength between pyramidal cells and interneurons in a cell type-specific manner and, in the defined CA1 interneurons, shifts the spatial pattern of inhibitory weight from pyramidal cell dendrites to the perisomatic region.

  16. Prenatal exposure to the CB1 and CB2 cannabinoid receptor agonist WIN 55,212-2 alters migration of early-born glutamatergic neurons and GABAergic interneurons in the rat cerebral cortex.

    Science.gov (United States)

    Saez, Trinidad M M; Aronne, María P; Caltana, Laura; Brusco, Alicia H

    2014-05-01

    The endocannabinoid system, composed of cannabinoid receptors, endocannabinoids, and synthesis and degradation enzymes, is present since early stages of brain development. During this period, the endocannabinoid system is involved in the regulation of neural progenitor proliferation and specification as well as the migration and differentiation of pyramidal neurons and interneurons. Marijuana consumption during pregnancy represents a serious risk in relation to the fetal brain development since Δ(9) -tetrahidrocannabinol, the main active compound of cannabis, can reach the fetus through placenta and hemato-encephalic barrier. Cohort studies performed on children and adolescents of mothers who consumed marijuana during pregnancy reported cognitive and comportamental abnormalities. In the present study, we examined the expression of the cannabinoid receptor CB1 R during corticogenesis in radially and tangentially migrating post-mitotic neurons. We found that prenatal exposure to WIN impaired tangential and radial migration of post-mitotic neurons in the dorsal pallium. In addition, we described alterations of two transcription factors associated with proliferating and newly post-mitotic glutamatergic cells in the dorsal pallium, Tbr1 and Tbr2, and disruption in the number of Cajal-Retzius cells. The present results contribute to the knowledge of neurobiological substrates that determine neuro-comportamental changes that will persist through post-natal life.

  17. Sperm Release From the Oviductal Epithelium Depends on Ca(2+) Influx Upon Activation of CB1 and TRPV1 by Anandamide.

    Science.gov (United States)

    Gervasi, M G; Osycka-Salut, C; Sanchez, T; Alonso, C A I; Llados, C; Castellano, L; Franchi, A M; Villalón, M; Perez-Martinez, S

    2016-02-01

    The oviduct acts as a functional sperm reservoir in many mammalian species. Both binding and release of spermatozoa from the oviductal epithelium are mainly modulated by sperm capacitation. Several molecules from oviductal fluid are involved in the regulation of sperm function. Anandamide is a lipid mediator involved in reproductive physiology. Previously, we demonstrated that anandamide, through activation of the cannabinoid receptor type 1 (CB1), promotes sperm release from bovine oviductal epithelial cells, and through CB1 and the transient receptor potential vanilloid 1 (TRPV1), induces sperm capacitation. Herein we investigate co-activation between CB1 and TRPV1, and Ca(2+) influx as part of the mechanism of action of anandamide during sperm release from oviductal cells. Our results indicate that in the absence of Ca(2+) anandamide failed to release spermatozoa from oviductal epithelial cells. Additionally, sperm release promoted by cannabinoid and vanilloid agonists was abolished when the spermatozoa were preloaded with BAPTA-AM, a Ca(2+) chelator. We also determined Ca(2+) levels in spermatozoa preloaded with FURA2-AM co-cultured with oviductal cells and incubated with different cannabinoid and vanilloid agonists. The incubation with different agonists induced Ca(2+) influx, which was abolished by CB1 or TRPV1 antagonists. Our results also suggest that a phospholypase C (PLC) might mediate the activation of CB1 and TRPV1 in sperm release from the bovine oviduct. Therefore, our findings indicate that anandamide, through CB1 and TRPV1 activation, is involved in sperm release from the oviductal reservoir. An increase of sperm Ca(2+) levels and the PLC activation might be involved in anandamide signaling pathway.

  18. Pro-epileptic effects of the cannabinoid receptor antagonist SR141716 in a model of audiogenic epilepsy

    NARCIS (Netherlands)

    Vinogradova, L.V.; Shatskova, A.B.; Rijn, C.M. van

    2011-01-01

    Endocannabinoid system and its CB1 receptors are suggested to provide endogeneous protection against seizures. The present study examines whether CB1 receptors contribute to resistance to seizures and kindling epileptogenesis in a model of audiogenic epilepsy. Three groups of Wistar rats were used:

  19. High affinity retinoic acid receptor antagonists: analogs of AGN 193109.

    Science.gov (United States)

    Johnson, A T; Wang, L; Gillett, S J; Chandraratna, R A

    1999-02-22

    A series of high affinity retinoic acid receptor (RAR) antagonists were prepared based upon the known antagonist AGN 193109 (2). Introduction of various phenyl groups revealed a preference for substitution at the para-position relative to the meta-site. Antagonists with the highest affinities for the RARs possessed hydrophobic groups, however, the presence of polar functionality was also well tolerated.

  20. Effects of WIN 55,212-2 (a synthetic cannabinoid CB1 and CB2 receptor agonist) on the anticonvulsant activity of various novel antiepileptic drugs against 6 Hz-induced psychomotor seizures in mice.

    Science.gov (United States)

    Florek-Luszczki, Magdalena; Wlaz, Aleksandra; Zagaja, Mirosław; Andres-Mach, Marta; Kondrat-Wrobel, Maria W; Luszczki, Jarogniew J

    2015-03-01

    The purpose of this study was to determine the influence of WIN 55,212-2 mesylate (WIN-a non-selective cannabinoid CB1 and CB2 receptor agonist) on the anticonvulsant activity of various second- and third-generation antiepileptic drugs (i.e., gabapentin, lacosamide, levetiracetam, oxcarbazepine, pregabalin and tiagabine) in the mouse 6 Hz-induced psychomotor seizure model. Psychomotor seizures were evoked in albino Swiss mice by a current (32 mA, 6 Hz, 3s stimulus duration) delivered via ocular electrodes. Additionally, total brain antiepileptic drug concentrations were measured. Results indicate that WIN (5 mg/kg, administered i.p.) significantly potentiated the anticonvulsant action of gabapentin (P < 0.05) and levetiracetam (P < 0.01), but not that of lacosamide, oxcarbazepine, pregabalin or tiagabine in the mouse psychomotor seizure model. Moreover, WIN (2.5 mg/kg) had no significant effect on the anticonvulsant activity of all tested antiepileptic drugs in the 6 Hz test in mice. Measurement of total brain antiepileptic drug concentrations revealed that WIN (5 mg/kg) had no impact on gabapentin or levetiracetam total brain concentrations, indicating the pharmacodynamic nature of interaction between these antiepileptic drugs in the mouse 6Hz model. In conclusion, WIN in combination with gabapentin and levetiracetam exerts beneficial anticonvulsant pharmacodynamic interactions in the mouse psychomotor seizure model.

  1. Influence of arachidonyl-2'-chloroethylamide, a selective cannabinoid CB1 receptor agonist, on the anticonvulsant and acute side-effect potentials of clobazam, lacosamide, and pregabalin in the maximal electroshock-induced seizure model and chimney test in mice.

    Science.gov (United States)

    Florek-Luszczki, Magdalena; Zagaja, Miroslaw; Luszczki, Jarogniew J

    2015-08-01

    The influence of arachidonyl-2'-chloroethylamide (ACEA - a selective cannabinoid CB1 receptor agonist) on the anticonvulsant potency and acute adverse-effect potentials of clobazam, lacosamide, and pregabalin was determined in the maximal electroshock-induced seizure model and chimney test in mice. ACEA (2.5 mg/kg, i.p.) significantly enhanced the anticonvulsant potency of pregabalin in the mouse maximal electroshock-induced seizure model by decreasing the median effective dose (ED50 ) of pregabalin from 125.39 to 78.06 mg/kg (P clobazam and lacosamide in the mouse maximal electroshock-induced seizure model. On the other hand, ACEA (2.5 mg/kg) did not affect acute adverse effects of clobazam, lacosamide or pregabalin, and the median toxic doses (TD50 ) for the studied anti-epileptic drugs in combination with ACEA did not differ from the TD50 values as determined for the drugs administered alone in the chimney test. In conclusion, ACEA ameliorates the pharmacological profile of pregabalin, when considering both the anticonvulsant and the acute adverse effects of the drug in preclinical study on animals. The combination of pregabalin with ACEA can be of pivotal importance for patients with epilepsy as a potentially advantageous combination if the results from this study translate into clinical settings.

  2. Reversible disruption of pre-pulse inhibition in hypomorphic-inducible and reversible CB1-/- mice.

    Directory of Open Access Journals (Sweden)

    Maria Franca Marongiu

    Full Text Available Although several genes are implicated in the pathogenesis of schizophrenia, in animal models for such a severe mental illness only some aspects of the pathology can be represented (endophenotypes. Genetically modified mice are currently being used to obtain or characterize such endophenotypes. Since its cloning and characterization CB1 receptor has increasingly become of significant physiological, pharmacological and clinical interest. Recently, its involvement in schizophrenia has been reported. Among the different approaches employed, gene targeting permits to study the multiple roles of the endocannabinoid system using knockout ((-/- mice represent a powerful model but with some limitations due to compensation. To overcome such a limitation, we have generated an inducible and reversible tet-off dependent tissue-specific CB1(-/- mice where the CB1R is re-expressed exclusively in the forebrain at a hypomorphic level due to a mutation (IRh-CB1(-/- only in absence of doxycycline (Dox. In such mice, under Dox(+ or vehicle, as well as in wild-type (WT and CB1(-/-, two endophenotypes motor activity (increased in animal models of schizophrenia and pre-pulse inhibition (PPI of startle reflex (disrupted in schizophrenia were analyzed. Both CB1(-/- and IRh-CB1(-/- showed increased motor activity when compared to WT animals. The PPI response, unaltered in WT and CB1(-/- animals, was on the contrary highly and significantly disrupted only in Dox(+ IRh-CB1(-/- mice. Such a response was easily reverted after either withdrawal from Dox or haloperidol treatment. This is the first Inducible and Reversible CB1(-/- mice model to be described in the literature. It is noteworthy that the PPI disruption is not present either in classical full CB1(-/- mice or following acute administration of rimonabant. Such a hypomorphic model may provide a new tool for additional in vivo and in vitro studies of the physiological and pathological roles of cannabinoid system in

  3. Multiple Targeting Approaches on Histamine H3 Receptor Antagonists.

    Science.gov (United States)

    Khanfar, Mohammad A; Affini, Anna; Lutsenko, Kiril; Nikolic, Katarina; Butini, Stefania; Stark, Holger

    2016-01-01

    With the very recent market approval of pitolisant (Wakix®), the interest in clinical applications of novel multifunctional histamine H3 receptor antagonists has clearly increased. Since histamine H3 receptor antagonists in clinical development have been tested for a variety of different indications, the combination of pharmacological properties in one molecule for improved pharmacological effects and reduced unwanted side-effects is rationally based on the increasing knowledge on the complex neurotransmitter regulations. The polypharmacological approaches on histamine H3 receptor antagonists on different G-protein coupled receptors, transporters, enzymes as well as on NO-signaling mechanism are described, supported with some lead structures.

  4. Multiple Targeting Approaches on Histamine H3 Receptor Antagonists

    Directory of Open Access Journals (Sweden)

    Mohammad eKhanfar

    2016-05-01

    Full Text Available With the very recent market approval of pitolisant (Wakix®, the interest in clinical applications of novel multifunctional histamine H3 receptor antagonists has clearly increased. Since histamine H3 receptor antagonists in clinical development have been tested for a variety of different indications, the combination of pharmacological properties in one molecule for improved pharmacological effects and reduced unwanted side-effects is rationally based on the increasing knowledge on the complex neurotransmitter regulations. The polypharmacological approaches on histamine H3 receptor antagonists on different G-protein coupled receptors, transporters, enzymes as well as on NO-signaling mechanism are described, supported with some lead structures.

  5. Antagonistic and inverse agonistic effect of M J15 on cannabinoid receptors Ⅰ%MJ15对大麻素Ⅰ型受体的阻滞及反相激动作用的研究

    Institute of Scientific and Technical Information of China (English)

    曹宁; 杨洋; 周晓棉; 徐成; 王莉莉

    2011-01-01

    Objective: To observe the antagonistic and inverse agonistic effect of MJ15 on cannabinoid receptors Ⅰ (CB1). Methods: The samples of the ileum smooth muscle isolated from guinea pigs and vas deferens isolated from mice were put into the Magnus' bath, and the contractive activities were investigated. Results: The CB1 receptor agonist WIN55212-2 ( 10 - 10 ~ 10 - 6 mol · L - 1 ) inhibited electrically induced contraction of mouse vas deferens; the concentration-dependency was significant. The concentration-response curse was completely inhibited by SR141716A and MJ15(l0-7 mol· L-1). WIN55212-2 inhibited contraction of mouse vas deferens and guinea pig ileum smooth muscle; while SR141716A and MJ15 accelerated the contraction. Conclusion: MJ15 is an antagonist of CB1 receptor with inverse agonistic activity.%目的:观察MJ15对大麻素Ⅰ型(cannabinoid receptors Ⅰ,CB1)受体的阻滞及反相激动作用.方法:制备小鼠输精管和豚鼠回肠平滑肌的离体标本,观察CB1受体激动剂WIN55212-2以及阻滞剂利莫那班(SR141716A)和MJ15对其收缩特性的影响.结果:CB1受体激动剂WIN55212-2(10-10~10-6 mol·L-1)可抑制电刺激所引起小鼠输精管的收缩作用,呈现明显的剂量依赖性,而SR141716A和MJ15(10-7mol·L-1)能阻滞WIN55212-2的抑制作用;CB1受体激动剂WIN55212-2可抑制豚鼠回肠和小鼠输精管平滑肌的收缩,而SR141716A和MJ15能促进豚鼠回肠和小鼠输精管平滑肌的收缩.结论:MJ15是CB1受体的阻滞剂,同时具有反相激动作用.

  6. Cannabinoid-1 receptor antagonists in type-2 diabetes.

    Science.gov (United States)

    Scheen, André J

    2007-12-01

    Type-2 diabetes is closely related to abdominal obesity and is generally associated with other cardiometabolic risk factors, resulting in a risk of major cardiovascular disease. Several animal and human observations suggest that the endocannabinoid system is over-active in the presence of abdominal obesity and/or diabetes. Both central and peripheral endocannabinoid actions, via the activation of CB1 receptors, promote weight gain and associated metabolic changes. Rimonabant, the first selective CB(1) receptor blocker in clinical use, has been shown to reduce body weight, waist circumference, triglycerides, blood pressure, insulin resistance index and C-reactive protein levels, and to increase high-density lipoprotein (HDL) cholesterol and adiponectin concentrations in both non-diabetic and diabetic overweight/obese patients. In addition, a 0.5-0.7% reduction in HbA1c levels was observed in metformin- or sulphonylurea-treated patients with type-2 diabetes and in drug-naïve diabetic patients. Almost half of the metabolic changes, including HbA1c reduction, could not be explained by weight loss, suggesting that there are direct peripheral effects. Rimonabant was generally well-tolerated, and the safety profile was similar in diabetic and non-diabetic patients, with a higher incidence of depressed mood disorders, nausea and dizziness. In conclusion, the potential role of rimonabant in overweight/obese patients with type-2 diabetes and at high risk of cardiovascular disease deserves much consideration.

  7. A pharmacophore model for dopamine D4 receptor antagonists

    Science.gov (United States)

    Boström, Jonas; Gundertofte, Klaus; Liljefors, Tommy

    2000-11-01

    A pharmacophore model for dopamine D4 antagonists has been developed on the basis of a previously reported dopamine D2 model. By using exhaustive conformational analyses (MM3* force field and the GB/SA hydration model) and least-squares molecular superimposition studies, a set of eighteen structurally diverse high affinity D4 antagonists have successfully been accommodated in the D4 pharmacophore model. Enantioselectivities may be rationalized by conformational energies required for the enantiomers to adopt their proposed bioactive conformations. The pharmacophore models for antagonists at the D4 and D2 receptor subtypes have been compared in order to get insight into molecular properties of importance for D2/D4 receptor selectivity. It is concluded that the bioactive conformations of antagonists at the two receptor subtypes are essentially identical. Receptor essential volumes previously identified for the D2 receptor are shown to be present also in the D4 receptor. In addition, a novel receptor essential volume in the D4 receptor, not present in the D2 receptor, has been identified. This feature may be exploited for the design of D4 selective antagonists. However, it is concluded that the major determinant for D2/D4 selectivity is the nature of the interactions between the receptor and aromatic ring systems. The effects of the electronic properties of these ring systems on the affinities for the two receptor subtypes differ substantially.

  8. Impaired cannabinoid receptor type 1 signaling interferes with stress-coping behavior in mice.

    Science.gov (United States)

    Steiner, M A; Wanisch, K; Monory, K; Marsicano, G; Borroni, E; Bächli, H; Holsboer, F; Lutz, B; Wotjak, C T

    2008-06-01

    Dysregulation of the endocannabinoid system is known to interfere with emotional processing of stressful events. Here, we studied the role of cannabinoid receptor type 1 (CB1) signaling in stress-coping behaviors using the forced swim test (FST) with repeated exposures. We compared effects of genetic inactivation with pharmacological blockade of CB1 receptors both in male and female mice. In addition, we investigated potential interactions of the endocannabinoid system with monoaminergic and neurotrophin systems of the brain. Naive CB1 receptor-deficient mice (CB1-/-) showed increased passive stress-coping behaviors as compared to wild-type littermates (CB1+/+) in the FST, independent of sex. These findings were partially reproduced in C57BL/6N animals and fully reproduced in female CB1+/+ mice by pharmacological blockade of CB1 receptors with the CB1 receptor antagonist SR141716. The specificity of SR141716 was confirmed in female CB1-/- mice, where it failed to affect behavioral performance. Sensitivity to the antidepressants desipramine and paroxetine was preserved, but slightly altered in female CB1-/- mice. There were no genotype differences between CB1+/+ and CB1-/- mice in monoamine oxidase A and B activities under basal conditions, nor in monoamine content of hippocampal tissue after FST exposure. mRNA expression of vesicular glutamate transporter type 1 was unaffected in CB1-/- mice, but mRNA expression of brain-derived neurotrophic factor (BDNF) was reduced in the hippocampus. Our results suggest that impaired CB1 receptor function promotes passive stress-coping behavior, which, at least in part, might relate to alterations in BDNF function.

  9. The PVH as a site of CB1-mediated stimulation of thermogenesis by MC4R agonism in male rats.

    Science.gov (United States)

    Monge-Roffarello, Boris; Labbe, Sebastien M; Roy, Marie-Claude; Lemay, Marie-Laurence; Coneggo, Estelle; Samson, Pierre; Lanfray, Damien; Richard, Denis

    2014-09-01

    The present study was designed to investigate the involvement of the cannabinoid receptor 1 (CB1) in the stimulating effects of the melanocortin-4 receptor (MC4R) agonism on whole-body and brown adipose tissue (BAT) thermogenesis. In a first series of experiments, whole-body and BAT thermogenesis were investigated in rats infused in the third ventricle of the brain with the MC4R agonist melanotan II (MTII) and the CB1 agonist δ9-tetrahydrocannabinol (δ(9)-THC) or the CB1 antagonist AM251. Whole-body thermogenesis was measured by indirect calorimetry and BAT thermogenesis assessed from interscapular BAT (iBAT) temperature. δ(9)-THC blunted the effects of MTII on energy expenditure and iBAT temperature, whereas AM251 tended to potentiate the MTII effects. δ(9)-THC also blocked the stimulating effect of MTII on (14)C-bromopalmitate and (3)H-deoxyglucose uptakes in iBAT. Additionally, δ(9)-THC attenuated the stimulating effect of MTII on the expression of peroxisome proliferator-activated receptor-γ coactivator 1-α (Pgc1α), type II iodothyronine deiodinase (Dio2), carnitine palmitoyltransferase 1B (Cpt1b), and uncoupling protein 1 (Ucp1). In a second series of experiments, we addressed the involvement of the paraventricular hypothalamic nucleus (PVH) in the CB1-mediated effects of MTII on iBAT thermogenesis, which were assessed following the infusion of MTII in the PVH and δ(9)-THC or AM251 in the fourth ventricle of the brain. We demonstrated the ability of δ(9)-THC to blunt MTII-induced iBAT temperature elevation. δ(9)-THC also blocked the PVH effect of MTII on (14)C-bromopalmitate uptake as well as on Pgc1α and Dio2 expression in iBAT. Altogether the results of this study demonstrate the involvement of the PVH in the CB1-mediated stimulating effects of the MC4R agonist MTII on whole-body and BAT thermogenesis.

  10. A SELECTIVE ANTAGONIST OF MINERALOCORTICOID RECEPTOR EPLERENONE IN CARDIOLOGY PRACTICE

    Directory of Open Access Journals (Sweden)

    B. B. Gegenava

    2015-09-01

    Full Text Available The role of aldosterone in pathophysiological processes is considered. The effects of the selective antagonist of mineralocorticoid receptor eplerenone are analyzed. The advantages of eplerenone compared with spironolactone are discussed.

  11. New antagonist agents of neuropeptide y receptors

    Directory of Open Access Journals (Sweden)

    Ignacio Aldana

    2000-12-01

    Full Text Available In the CNS, NPY has been implicated in obesity and feeding, endocrine function and metabolism. Potent and selective rNPY antagonists will be able to probe the merits of this approach for the treatment of obesity. We report the synthesis and preliminary evaluation of some hydrazide derivatives as antagonists of rNPY.

  12. Histamine-2 receptor antagonists as immunomodulators: new therapeutic views?

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen

    1996-01-01

    from such studies are currently accumulating and suggest that the histamine-2 receptor antagonists have potential beneficial effects in the treatment of certain malignant, autoimmune and skin diseases, either alone or in combination with other drugs. The beneficial effect of histamine-2 receptor...... antagonists as adjuvant single drugs to reduce trauma-, blood transfusion- and sepsis-induced immunosuppression has led to research in combined treatment regimens in major surgery, particularly, of patients operated on for malignant diseases....

  13. Deficiency of interleukin-1 receptor antagonist responsive to anakinra.

    Science.gov (United States)

    Schnellbacher, Charlotte; Ciocca, Giovanna; Menendez, Roxanna; Aksentijevich, Ivona; Goldbach-Mansky, Raphaela; Duarte, Ana M; Rivas-Chacon, Rafael

    2013-01-01

    We describe a 3-month-old infant who presented to our institution with interleukin (IL)-1 receptor antagonist deficiency (DIRA), which consists of neutrophilic pustular dermatosis, periostitis, aseptic multifocal osteomyelitis, and persistently high acute-phase reactants. Skin findings promptly improved upon initiation of treatment with anakinra (recombinant human IL-1 receptor antagonist), and the bony lesions and systemic inflammation resolved with continued therapy.

  14. Multiple Targeting Approaches on Histamine H3 Receptor Antagonists

    OpenAIRE

    Mohammad eKhanfar; Anna eAffini; Kiril eLutsenko; Katarina eNikolic; Stefania eButini; Holger eStark

    2016-01-01

    With the very recent market approval of pitolisant (Wakix®), the interest in clinical applications of novel multifunctional histamine H3 receptor antagonists has clearly increased. Since histamine H3 receptor antagonists in clinical development have been tested for a variety of different indications, the combination of pharmacological properties in one molecule for improved pharmacological effects and reduced unwanted side-effects is rationally based on the increasing knowledge on the complex...

  15. Interleukin-2 receptor antagonists as induction therapy after heart transplantation

    DEFF Research Database (Denmark)

    Møller, Christian H; Gustafsson, Finn; Gluud, Christian;

    2008-01-01

    About half of the transplantation centers use induction therapy after heart transplantation. Interleukin-2 receptor antagonists (IL-2Ras) are used increasingly for induction therapy. We conducted a systematic review of randomized trials assessing IL-2Ras.......About half of the transplantation centers use induction therapy after heart transplantation. Interleukin-2 receptor antagonists (IL-2Ras) are used increasingly for induction therapy. We conducted a systematic review of randomized trials assessing IL-2Ras....

  16. CB1 Knockout Mice Unveil Sustained CB2-Mediated Antiallodynic Effects of the Mixed CB1/CB2 Agonist CP55,940 in a Mouse Model of Paclitaxel-Induced Neuropathic Pain

    OpenAIRE

    Deng, Liting; Cornett, Benjamin L.; Mackie, Ken; Hohmann, Andrea G.

    2015-01-01

    Cannabinoids suppress neuropathic pain through activation of cannabinoid CB1 and/or CB2 receptors; however, unwanted CB1-mediated cannabimimetic effects limit clinical use. We asked whether CP55,940 [(−)-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-4-(3-hydroxypropyl)cyclohexanol], a potent cannabinoid that binds with similar affinity to CB1 and CB2 in vitro, produces functionally separable CB1- and CB2-mediated pharmacological effects in vivo. We evaluated antiallodynic effects, possible toler...

  17. Aspirin-triggered lipoxin induces CB1-dependent catalepsy in mice.

    Science.gov (United States)

    Pamplona, Fabrício A; Menezes-de-Lima, Octávio; Takahashi, Reinaldo N

    2010-02-05

    Evidence are that inhibition of cyclooxygenase 2 (COX-2) enhances endocannabinoid signaling, indicating a crosstalk between these two eicosanoid pathways. Aspirin, a non-selective COX inhibitor, acetylates COX-2 with generation of a lipoxygenase (LOX) substrate, whose end product is the 15-epi-lipoxin A(4) (15-epi-LXA(4)), an aspirin-triggered lipoxin. Our objective was to investigate whether 15-epi-LXA(4) would potentiate in vivo effects of the endocannabinoid anandamide (AEA). Catalepsy was selected as a behavioral parameter and tested 5 min after AEA injection in all experiments. AEA induced dose-dependent (200 pmol/2 microl, i.c.v.) catalepsy. A sub-dose of AEA (10 pmol/2 microl, i.c.v.) was potentiated by aspirin (300 mg/kg, p.o.) via a 5-LOX-dependent step. The cataleptic effect induced by the interaction between sub-doses of 15-epi-LXA(4) (0.01 pmol/2 microl, i.c.v.) and AEA (10 pmol/2 microl, i.c.v.) was prevented by the cannabinoid CB(1) receptors antagonist SR141716A (1mg/kg, i.p.), but not by the antagonist of lipoxin ALX receptors Boc-2 (10 microg/kg, i.p.). While previous studies have shown that COX inhibition itself may enhance endocannabinoid effects, here we add another piece of evidence revealing that a LOX-derivative produced in consequence of COX-2 acetylation participates in this process.

  18. Targeting Cannabinoid CB2 Receptors in the Central Nervous System. Medicinal Chemistry Approaches with Focus on Neurodegenerative Disorders

    OpenAIRE

    Gema Navarro; Paula Morales; Carmen Rodríguez-Cueto; Javier Fernández-Ruiz; Nadine Jagerovic; Rafael Franco

    2016-01-01

    Endocannabinoids activate two types of specific G-protein-coupled receptors (GPCRs), namely cannabinoid CB1 and CB2. Contrary to the psychotropic actions of agonists of CB1 receptors, and serious side effects of the selective antagonists of this receptor, drugs acting on CB2 receptors appear as promising drugs to combat CNS diseases (Parkinson's disease, Huntington's chorea, cerebellar ataxia, amyotrohic lateral sclerosis). Differential localization of CB2 receptors in neural cell types and u...

  19. Identification of a novel conformationally constrained glucagon receptor antagonist.

    Science.gov (United States)

    Lee, Esther C Y; Tu, Meihua; Stevens, Benjamin D; Bian, Jianwei; Aspnes, Gary; Perreault, Christian; Sammons, Matthew F; Wright, Stephen W; Litchfield, John; Kalgutkar, Amit S; Sharma, Raman; Didiuk, Mary T; Ebner, David C; Filipski, Kevin J; Brown, Janice; Atkinson, Karen; Pfefferkorn, Jeffrey A; Guzman-Perez, Angel

    2014-02-01

    Identification of orally active, small molecule antagonists of the glucagon receptor represents a novel treatment paradigm for the management of type 2 diabetes mellitus. The present work discloses novel glucagon receptor antagonists, identified via conformational constraint of current existing literature antagonists. Optimization of lipophilic ligand efficiency (LLE or LipE) culminated in enantiomers (+)-trans-26 and (-)-trans-27 which exhibit good physicochemical and in vitro drug metabolism profiles. In vivo, significant pharmacokinetic differences were noted with the two enantiomers, which were primarily driven through differences in clearance rates. Enantioselective oxidation by cytochrome P450 was ruled out as a causative factor for pharmacokinetic differences.

  20. Antagonists of the kappa opioid receptor.

    Science.gov (United States)

    Urbano, Mariangela; Guerrero, Miguel; Rosen, Hugh; Roberts, Edward

    2014-05-01

    The research community has increasingly focused on the development of OPRK antagonists as pharmacotherapies for the treatment of depression, anxiety, addictive disorders and other psychiatric conditions produced or exacerbated by stress. Short-acting OPRK antagonists have been recently developed as a potential improvement over long-acting prototypic ligands including nor-BNI and JDTic. Remarkably the short-acting LY2456302 is undergoing phase II clinical trials for the augmentation of the antidepressant therapy in treatment-resistant depression. This Letter reviews relevant chemical and pharmacological advances in the identification and development of OPRK antagonists.

  1. Approaches to the rational design of selective melanocortin receptor antagonists

    Science.gov (United States)

    Hruby, Victor J; Cai, Minying; Nyberg, Joel; Muthu, Dhanasekaran

    2015-01-01

    Introduction When establishing the physiological roles of specific receptors in normal and disease states, it is critical to have selective antagonist ligands for each receptor in a receptor system with several subtypes. The melanocortin receptors have five subtypes referred to as the melanocortin 1 receptor, melanocortin 2 receptor, melanocortin 3 receptor, melanocortin 4 receptor and melanocortin 5 receptor, and they are of critical importance for many aspects of human health and disease. Areas covered This article reviews the current efforts to design selective antagonistic ligands for the five human melanocortin receptors summarizing the currently published orthosteric and allosteric antagonists for each of these receptors. Expert opinion Though there has been progress, there are still few drugs available that address the many significant biological activities and diseases that are associated with these receptors, which is possibly due to the lack of receptor selectivity that these designed ligands are currently showing. The authors believe that further studies into the antagonists’ 3D conformational and topographical properties in addition to future mutagenesis studies will provide greater insight into these ligands which could play a role in the treatment of various diseases in the future. PMID:22646078

  2. 选择性1型大麻素受体阻滞剂利莫那班%Rimonabant-a selective CB1 endocannabinoid receptor antagonist

    Institute of Scientific and Technical Information of China (English)

    史爱欣

    2006-01-01

    利莫那班是选择性大麻素受体1(CBR1)阻滞剂,在对肥胖、戒烟以及代谢综合征治疗中具有良好作用,是惟一用于临床控制食欲和降低体重的内源性大麻素受体阻滞剂.现对其药理作用以及临床评价做一综述.

  3. GPR55: a new member of the cannabinoid receptor clan?

    OpenAIRE

    Pertwee, R. G.

    2007-01-01

    In this issue of the British Journal of Pharmacology, Ryberg et al. present convincing in vitro evidence that the orphan GPCR, GPR55, is a cannabinoid receptor. GPR55 was activated by a range of plant, synthetic and endogenous cannabinoids and blocked by the non-psychoactive phytocannabinoid, cannabidiol. Their experiments have revealed several differences between the pharmacology of GPR55 and the established cannabinoid CB1 and CB2 receptors. For example, the CB1 receptor antagonist, AM251, ...

  4. Expression of cannabinoid receptor 1 in hippocampus of sleep deprived rats following epilepsy%癫(癎)诱发后CB1受体在睡眠剥夺大鼠海马表达的研究

    Institute of Scientific and Technical Information of China (English)

    江佩芳; 夏哲智; 江克文; 杨翠薇; 水泉祥

    2007-01-01

    目的 探讨癫(癎)诱发后大麻素CB1受体在睡眠剥夺大鼠海马的表达变化及其意义.方法 50只Sprague-Dawlev大鼠随机分为癫(癎)诱发前和癫闡诱发后2组,每组25只.每组大鼠又随机分为空白对照组(CC),环境对照组(TC)和睡眠剥夺1 d、3 d、5 d组(SD1d、SD3d、SD5d).用改良多平台睡眠剥夺法建立快速眼球运动(REM)睡眠剥夺模型,戊四氮诱发癫(癎).应用RT-PCR方法检测癫(癎)诱发前后大麻素CB1受体mRNA表达,并电镜观察其海马的超微结构改变.结果 SD1d组神经元轻度固缩,染色质轻度边聚,SD3d组神经元凋亡,SD5d组超微结构改变基本同SD3d组.癫(癎)诱发后发现CC组与TC组大鼠无抽搐,CB1受体mRNA表达较癫(癎)诱发前明显升高(P<0.01).SD1d、SD3d、SD5d组大鼠抽搐严重,CB1受体mRNA表达与癫(癎)诱发前相比差异无统计学意义(P>0.05).结论 睡眠剥夺能够造成神经元凋亡,影响大麻素CB1受体mRNA表达.大麻素CB1受体表达增高可能是一种自身稳定调节的保护机制,能抑制癫(癎)发作.

  5. The cannabinoid receptor 1 expression in rat hippocampus and brainstem after rapid eye movement sleep deprivation%睡眠剥夺对大鼠脑干和海马大麻素CB-1受体的影响

    Institute of Scientific and Technical Information of China (English)

    朱涛; 江佩芳; 夏哲智; 水泉祥; 潘孔寒; 王丽

    2006-01-01

    目的 探讨快速眼动(REM)睡眠剥夺(SD)对大鼠脑干和海马大麻素CB-1受体的影响.方法 采用改良多平台睡眠剥夺法建立REM睡眠剥夺模型.将40只Sprague-Dawley大鼠随机分为空白对照组(CC)、环境对照组(TC),以及睡眠剥夺1 d(SD1 d)、3 d(SD3 d)和5 d(SD5 d)组,每组8只.应用逆转录-聚合酶链反应方法检测大鼠脑干及海马CB-1受体mRNA的表达,电镜观察其超微结构的改变.结果 SD各组大鼠脑干与海马超微结构均有神经元凋亡,SD3 d和SD5 d组尤著.(1)脑干CB-1受体mRNA表达值:SD1 d组(0.789±0.139)和SD3 d组(1.264±0.182)均高于CC组(0.420±0.054),且SD3 d组高于SD1 d组(P<0.05),SD5 d组(0.678±0.145)与CC组的差异无统计学意义(P>0.05).(2)海马CB-1受体mRNA表达值:SD1 d组(0.598±0.098)高于CC组(0.374±0.064),SD3 d组(0.258±0.072)低于CC组,且SD3 d组低于SD1 d组(P<0.05);SD5 d组(0.448±0.177)与CC组的差异无统计学意义(P>0.05).结论 REM睡眠剥夺能造成脑干及海马神经元的损伤,在不同睡眠剥夺时期CB-1受体mRNA表达不同,其中CB-1受体表达增强可能是一种自身稳定调节的保护机制.

  6. Endogenous vs Exogenous Allosteric Modulators in GPCRs: A dispute for shuttling CB1 among different membrane microenvironments

    Science.gov (United States)

    Stornaiuolo, Mariano; Bruno, Agostino; Botta, Lorenzo; Regina, Giuseppe La; Cosconati, Sandro; Silvestri, Romano; Marinelli, Luciana; Novellino, Ettore

    2015-10-01

    A Cannabinoid Receptor 1 (CB1) binding site for the selective allosteric modulator ORG27569 is here identified through an integrate approach of consensus pocket prediction, mutagenesis studies and Mass Spectrometry. This unprecedented ORG27569 pocket presents the structural features of a Cholesterol Consensus Motif, a cholesterol interacting region already found in other GPCRs. ORG27569 and cholesterol affects oppositely CB1 affinity for orthosteric ligands. Moreover, the rise in cholesterol intracellular level results in CB1 trafficking to the axonal region of neuronal cells, while, on the contrary, ORG27568 binding induces CB1 enrichment at the soma. This control of receptor migration among functionally different membrane regions of the cell further contributes to downstream signalling and adds a previously unknown mechanism underpinning CB1 modulation by ORG27569 , that goes beyond a mere control of receptor affinity for orthosteric ligands.

  7. Tricyclic pyrazoles. Part 8. Synthesis, biological evaluation and modelling of tricyclic pyrazole carboxamides as potential CB2 receptor ligands with antagonist/inverse agonist properties.

    Science.gov (United States)

    Deiana, Valeria; Gómez-Cañas, María; Pazos, M Ruth; Fernández-Ruiz, Javier; Asproni, Battistina; Cichero, Elena; Fossa, Paola; Muñoz, Eduardo; Deligia, Francesco; Murineddu, Gabriele; García-Arencibia, Moisés; Pinna, Gerard A

    2016-04-13

    Previous studies have investigated the relevance and structure-activity relationships (SARs) of pyrazole derivatives in relation with cannabinoid receptors, and the series of tricyclic 1,4-dihydroindeno[1,2-c]pyrazoles emerged as potent CB2 receptor ligands. In the present study, novel 1,4-dihydroindeno[1,2-c]pyrazole and 1H-benzo[g]indazole carboxamides containing a cyclopropyl or a cyclohexyl substituent were designed and synthesized to evaluate the influence of these structural modifications towards CB1 and CB2 receptor affinities. Among these derivatives, compound 15 (6-cyclopropyl-1-(2,4-dichlorophenyl)-N-(adamantan-1-yl)-1,4-dihydroindeno[1,2-c]pyrazole-3-carboxamide) showed the highest CB2 receptor affinity (Ki = 4 nM) and remarkable selectivity (KiCB1/KiCB2 = 2232), whereas a similar affinity, within the nM range, was seen for the fenchyl derivative (compound 10: Ki = 6 nM), for the bornyl analogue (compound 14: Ki = 38 nM) and, to a lesser extent, for the aminopiperidine derivative (compound 6: Ki = 69 nM). Compounds 10 and 14 were also highly selective for the CB2 receptor (KiCB1/KiCB2 > 1000), whereas compound 6 was relatively selective (KiCB1/KiCB2 = 27). The four compounds were also subjected to GTPγS binding analysis showing antagonist/inverse agonist properties (IC50 for compound 14 = 27 nM, for 15 = 51 nM, for 10 = 80 nM and for 6 = 294 nM), and this activity was confirmed for the three more active compounds in a CB2 receptor-specific in vitro bioassay consisting in the quantification of prostaglandin E2 release by LPS-stimulated BV2 cells, in the presence and absence of WIN55,212-2 and/or the investigated compounds. Modelling studies were also conducted with the four compounds, which conformed with the structural requirements stated for the binding of antagonist compounds to the human CB2 receptor.

  8. Effects of a Cannabinoid1 receptor antagonist and Serotonin2C receptor agonist alone and in combination on motivation for palatable food: a dose-addition analysis study in mice.

    Science.gov (United States)

    Ward, Sara Jane; Lefever, Timothy W; Jackson, Cavario; Tallarida, Ronald J; Walker, Ellen A

    2008-05-01

    The cannabinoid and serotonin systems modulate feeding behavior in humans and laboratory animals. The present study assessed whether a cannabinoid (CB)(1) receptor antagonist and a serotonin (5-HT)(2C) receptor agonist alone and in combination attenuate motivation for the liquid nutritional drink Ensure as measured by a progressive ratio (PR) schedule of reinforcement in male C57BL/6 mice. Pretreatment (15 min i.p.) with either the CB(1) receptor antagonist N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboximide hydrochloride (SR141716) (SR; Rimonabant or Acomplia) or the 5-HT(2C) receptor agonist m-chlorophenylpiperazine (mCPP) dose-dependently decreased the maximum ratio completed under the PR schedule (break point) in mice. ED(25) values for SR and mCPP to decrease break point were determined, and the relative potency of each drug alone was quantified. Fixed dose-ratio pairs of SR/mCPP based on their relative potency were then administered. Dose-addition analysis comparing the experimentally determined potency for SR/mCPP combinations with their predicted additive potency revealed that SR/mCPP combinations in 1:1 and 2:1 ratios based on relative potency produced significant synergistic attenuation of break point for Ensure. The ED(25) values for decreasing break point were consistently lower than ED(25) values for decreasing response rate, and synergistic effects of SR/mCPP combinations on break point were seen independent of synergistic effects on response rate. These results indicate that cannabinoid CB(1) and serotonin 5-HT(2C) receptors are involved in motivated feeding behavior in mice and that these compounds can synergistically modulate motivation for palatable food with the synergy dependent upon the ratio of SR/mCPP in the combination.

  9. Cannabinoid-based drugs targeting CB1 and TRPV1, the sympathetic nervous system, and arthritis.

    Science.gov (United States)

    Lowin, Torsten; Straub, Rainer H

    2015-09-06

    Chronic inflammation in rheumatoid arthritis (RA) is accompanied by activation of the sympathetic nervous system, which can support the immune system to perpetuate inflammation. Several animal models of arthritis already demonstrated a profound influence of adrenergic signaling on the course of RA. Peripheral norepinephrine release from sympathetic terminals is controlled by cannabinoid receptor type 1 (CB1), which is activated by two major endocannabinoids (ECs), arachidonylethanolamine (anandamide) and 2-arachidonylglycerol. These ECs also modulate function of transient receptor potential channels (TRPs) located on sensory nerve fibers, which are abundant in arthritic synovial tissue. TRPs not only induce the sensation of pain but also support inflammation via secretion of pro-inflammatory neuropeptides. In addition, many cell types in synovial tissue express CB1 and TRPs. In this review, we focus on CB1 and transient receptor potential vanilloid 1 (TRPV1)-mediated effects on RA since most anti-inflammatory mechanisms induced by cannabinoids are attributed to cannabinoid receptor type 2 (CB2) activation. We demonstrate how CB1 agonism or antagonism can modulate arthritic disease. The concept of functional antagonism with continuous CB1 activation is discussed. Since fatty acid amide hydrolase (FAAH) is a major EC-degrading enzyme, the therapeutic possibility of FAAH inhibition is studied. Finally, the therapeutic potential of ECs is examined since they interact with cannabinoid receptors and TRPs but do not produce central side effects.

  10. Dissociation between the panicolytic effect of cannabidiol microinjected into the substantia nigra, pars reticulata, and fear-induced antinociception elicited by bicuculline administration in deep layers of the superior colliculus: The role of CB1-cannabinoid receptor in the ventral mesencephalon.

    Science.gov (United States)

    da Silva, Juliana Almeida; Biagioni, Audrey Francisco; Almada, Rafael Carvalho; de Souza Crippa, José Alexandre; Cecílio Hallak, Jaime Eduardo; Zuardi, Antônio Waldo; Coimbra, Norberto Cysne

    2015-07-05

    Many studies suggest that the substantia nigra, pars reticulata (SNpr), a tegmental mesencephalic structure rich in γ-aminobutyric acid (GABA)- and cannabinoid receptor-containing neurons, is involved in the complex control of defensive responses through the neostriatum-nigral disinhibitory and nigro-tectal inhibitory GABAergic pathways during imminently dangerous situations. The aim of the present work was to investigate the role played by CB1-cannabinoid receptor of GABAergic pathways terminal boutons in the SNpr or of SNpr-endocannabinoid receptor-containing interneurons on the effect of intra-nigral microinjections of cannabidiol in the activity of nigro-tectal inhibitory pathways. GABAA receptor blockade in the deep layers of the superior colliculus (dlSC) elicited vigorous defensive behaviour. This explosive escape behaviour was followed by significant antinociception. Cannabidiol microinjection into the SNpr had a clear anti-aversive effect, decreasing the duration of defensive alertness, the frequency and duration of defensive immobility, and the frequency and duration of explosive escape behaviour, expressed by running and jumps, elicited by transitory GABAergic dysfunction in dlSC. However, the innate fear induced-antinociception was not significantly changed. The blockade of CB1 endocannabinoid receptor in the SNpr decreased the anti-aversive effect of canabidiol based on the frequency and duration of defensive immobility, the frequency of escape expressed by running, and both the frequency and duration of escape expressed by jumps. These findings suggest a CB1 mediated endocannabinoid signalling in cannabidiol modulation of panic-like defensive behaviour, but not of innate fear-induced antinociception evoked by GABAA receptor blockade with bicuculline microinjection into the superior colliculus, with a putative activity in nigro-collicular GABAergic pathways.

  11. Activation of the sympathetic nervous system mediates hypophagic and anxiety-like effects of CB₁ receptor blockade.

    Science.gov (United States)

    Bellocchio, Luigi; Soria-Gómez, Edgar; Quarta, Carmelo; Metna-Laurent, Mathilde; Cardinal, Pierre; Binder, Elke; Cannich, Astrid; Delamarre, Anna; Häring, Martin; Martín-Fontecha, Mar; Vega, David; Leste-Lasserre, Thierry; Bartsch, Dusan; Monory, Krisztina; Lutz, Beat; Chaouloff, Francis; Pagotto, Uberto; Guzman, Manuel; Cota, Daniela; Marsicano, Giovanni

    2013-03-19

    Complex interactions between periphery and the brain regulate food intake in mammals. Cannabinoid type-1 (CB1) receptor antagonists are potent hypophagic agents, but the sites where this acute action is exerted and the underlying mechanisms are not fully elucidated. To dissect the mechanisms underlying the hypophagic effect of CB1 receptor blockade, we combined the acute injection of the CB1 receptor antagonist rimonabant with the use of conditional CB1-knockout mice, as well as with pharmacological modulation of different central and peripheral circuits. Fasting/refeeding experiments revealed that CB1 receptor signaling in many specific brain neurons is dispensable for the acute hypophagic effects of rimonabant. CB1 receptor antagonist-induced hypophagia was fully abolished by peripheral blockade of β-adrenergic transmission, suggesting that this effect is mediated by increased activity of the sympathetic nervous system. Consistently, we found that rimonabant increases gastrointestinal metabolism via increased peripheral β-adrenergic receptor signaling in peripheral organs, including the gastrointestinal tract. Blockade of both visceral afferents and glutamatergic transmission in the nucleus tractus solitarii abolished rimonabant-induced hypophagia. Importantly, these mechanisms were specifically triggered by lipid-deprivation, revealing a nutrient-specific component acutely regulated by CB1 receptor blockade. Finally, peripheral blockade of sympathetic neurotransmission also blunted central effects of CB1 receptor blockade, such as fear responses and anxiety-like behaviors. These data demonstrate that, independently of their site of origin, important effects of CB1 receptor blockade are expressed via activation of peripheral sympathetic activity. Thus, CB1 receptors modulate bidirectional circuits between the periphery and the brain to regulate feeding and other behaviors.

  12. Serotonin 2A receptor antagonists for treatment of schizophrenia

    DEFF Research Database (Denmark)

    Ebdrup, Bjørn Hylsebeck; Rasmussen, Hans; Arnt, Jørn;

    2011-01-01

    Introduction: All approved antipsychotic drugs share an affinity for the dopamine 2 (D2) receptor; however, these drugs only partially ameliorate the symptoms of schizophrenia. It is, therefore, of paramount importance to identify new treatment strategies for schizophrenia. Areas covered: Preclin......Introduction: All approved antipsychotic drugs