Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P21554 (cannabinoid receptor)
3,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Anandamide (arachidonoylethanolamide), an endogenous cannabinoid receptor ligand has been suggested to have physiological role in mammalian nervous system. However, little is known about the role of anandamide on neuronal cells. Here, we demonstrate that anandamide causes death of PC-12 cells, showing marked DNA condensation and fragmentation, appearance of cells at sub-G(0)/G(1) and redistribution of phosphatidyl serine, the hallmark features of apoptosis. Anandamide raised intracellular superoxide level and CPP32-like protease activity in PC-12 cells markedly. Furthermore, antioxidant N-acetyl cysteine prevented anandamide-induced superoxide anion formation and cell death, implying that intracellular superoxide is a novel mediator of anandamide-induced apoptosis of PC-12 cells.
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PMID:Anandamide induces apoptosis of PC-12 cells: involvement of superoxide and caspase-3. 1078 1

Delta(9)-tetrahydrocannabinol (THC), the principal psychoactive component of marijuana, is associated with impaired cognition and altered cortical function. THC transduces its central effects via activation of the G-protein linked cannabinoid receptor CB1. In this study we report that THC induces morphological degenerative changes in cultured cortical neurones, such as membrane blebbing and formation of apoptotic bodies, that are consistent with the apoptotic pathway of cell death. The THC-induced apoptosis was blocked by the CB1 receptor antagonist AM251 and pertussis toxin (PTX), suggesting that this effect of THC involves receptor-mediated activation of the G-protein subtypes G(i) or G(o). THC also promoted translocation of mitochondrial cytochrome c to the cytosol and increased the activity of the cysteine protease caspase-3, in a PTX-sensitive manner. The results from this study suggest that coupling of THC to a PTX-sensitive G-protein promotes cytochrome c release, caspase-3 activation and subsequent degeneration of cultured cortical neurones. This apoptotic pathway may underlie the compromised neuronal function that is associated with marijuana usage.
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PMID:Tetrahydrocannabinol-induced apoptosis of cultured cortical neurones is associated with cytochrome c release and caspase-3 activation. 1131 98

Delta 9-tetrahydrocannabinol, the principal psychoactive component of marijuana, exerts a variety of effects on the CNS, including impaired cognitive function and neurobehavioural deficits. The mechanisms underlying these neuronal responses to tetrahydrocannabinol are unclear but may involve alterations in neuronal viability. Tetrahydrocannabinol has been shown to influence neuronal survival but the role of the cannabinoid receptors in the regulation of neuronal viability has not been fully clarified. In this study we demonstrate that tetrahydrocannabinol promotes the release of cytochrome c, activates caspase-3, promotes cleavage of the DNA repair enzyme poly-ADP ribose polymerase and induces DNA fragmentation in cultured cortical neurones. These effects of tetrahydrocannabinol were completely abrogated by the CB(1) receptor antagonist AM-251. The findings of this study demonstrate that tetrahydrocannabinol induces apoptosis in cortical neurones in a manner involving the CB1 subtype of cannabinoid receptor.
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PMID:Delta 9-tetrahydrocannabinol induces the apoptotic pathway in cultured cortical neurones via activation of the CB1 receptor. 1174 22

Delta9-Tetrahydrocannabinol (THC), the main psychoactive ingredient of marijuana, induces apoptosis in cultured cortical neurons. THC exerts its apoptotic effects in cortical neurons by binding to the CB1 cannabinoid receptor. The CB1 receptor has been shown to couple to the stress-activated protein kinase, c-Jun N-terminal kinase (JNK). However, the involvement of specific JNK isoforms in the neurotoxic properties of THC remains to be established. The present study involved treatment of rat cultured cortical neurons with THC (0.005-50 microM), and combinations of THC with the CB1 receptor antagonist, AM 251 (10 microM) and pertussis toxin (PTX; 200 ng ml-1). Antisense oligonucleotides (AS) were used to deplete neurons of JNK1 and JNK2 in order to elucidate their respective roles in THC signalling. Here we report that THC induces the activation of JNK via the CB1 receptor and its associated G-protein, Gi/o. Treatment of cultured cortical neurons with THC resulted in a differential timeframe of activation of the JNK1 and JNK2 isoforms. Use of specific JNK1 and JNK2 AS identified activation of caspase-3 and DNA fragmentation as downstream consequences of JNK1 and JNK2 activation. The results from this study demonstrate that activation of the CB1 receptor induces JNK and caspase-3 activation, an increase in Bax expression and DNA fragmentation. The data demonstrate that the activation of both JNK1 and JNK2 isoforms is central to the THC-induced activation of the apoptotic pathway in cortical neurons.
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PMID:Tetrahydrocannabinol-induced neurotoxicity depends on CB1 receptor-mediated c-Jun N-terminal kinase activation in cultured cortical neurons. 1452 39

We have recently shown that cannabinoids induce growth inhibition and apoptosis in mantle cell lymphoma (MCL), a malignant B-cell lymphoma that expresses high levels of cannabinoid receptor types 1 and 2 (CB(1) and CB(2)). In the current study, the role of each receptor and the signal transduction triggered by receptor ligation were investigated. Induction of apoptosis after treatment with the synthetic agonists R(+)-methanandamide [R(+)-MA] and Win55,212-2 (Win55; (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl) pyrrolo-[1,2,3-d,e]-1,4-benzoxazin-6-yl]-1-naphthalenyl-methanone) was dependent on both cannabinoid receptors, because pretreatment with N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboximide hydrochloride (SR141716A) and N-((1S)-endo-1,3,3-trimethyl bicyclo heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide) (SR144528), specific antagonists to CB(1) and CB(2), respectively, abrogated caspase-3 activity. Preincubation with the inhibitors 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB203580) and 4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)-1H-imidazole (SB202190) showed that phosphorylation of MAPK p38 was implicated in the signal transduction leading to apoptosis. Treatment with R(+)-MA and Win55 was associated with accumulation of ceramide, and pharmacological inhibition of ceramide synthesis de novo prevented both p38 activation and mitochondria depolarization assessed by binding of 3,3'-dihexyloxacarbocyanine iodide (DiOC(6)). In contrast, the pancaspase inhibitor z-Val-Ala-Asp(Ome)-CH(2)F (z-VAD-FMK) did not protect the mitochondrial integrity. Taken together, these results suggest that concurrent ligation of CB(1) and CB(2) with either R(+)-MA or Win55 induces apoptosis via a sequence of events in MCL cells: accumulation of ceramide, phosphorylation of p38, depolarization of the mitochondrial membrane, and caspase activation. Although induction of apoptosis was observed in both MCL cell lines and primary MCL, normal B cells remained unaffected. The present data suggest that targeting CB(1)/CB(2) may have therapeutic potential for the treatment of mantle cell lymphoma.
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PMID:Cannabinoid receptor-mediated apoptosis induced by R(+)-methanandamide and Win55,212-2 is associated with ceramide accumulation and p38 activation in mantle cell lymphoma. 1693 28

Cannabis is the most commonly used illegal drug of abuse in Western society. Delta(9)-tetrahydrocannabinol, the psychoactive ingredient of marijuana, regulates a variety of neuronal processes including neurotransmitter release and synaptic transmission. An increasing body of evidence suggests that cannabinoids play a key role in the regulation of neuronal viability. In cortical neurons tetrahydrocannabinol has a neurodegenerative effect, the mechanisms of which are poorly understood, but involve the cannabinoid receptor subtype, CB(1). In this study we report that tetrahydrocannabinol (5 muM) evokes a rapid phosphorylation, and thus activation, of the tumour suppressor protein, p53, in a manner involving the cannabinoid CB(1) receptor, and the stress-activated protein kinase, c-jun N-terminal kinase, in cultured cortical neurons. Tetrahydrocannabinol increased expression of the p53-transcriptional target, Bax and promoted Bcl phosphorylation. These events were abolished by the p53 inhibitor, pifithrin-alpha (100 nM). The tetrahydrocannabinol-induced activation of the pro-apoptotic cysteine protease, caspase-3, and DNA fragmentation was also blocked by pifithrin-alpha. A siRNA knockdown of p53 further verified the role of p53 in tetrahydrocannabinol-induced apoptosis. This study demonstrates a novel cannabinoid signalling pathway involving p53 that culminates in neuronal apoptosis.
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PMID:The tumour suppressor protein, p53, is involved in the activation of the apoptotic cascade by Delta9-tetrahydrocannabinol in cultured cortical neurons. 1737 9

Colorectal cancer is an increasingly important cause of death in Western countries. Endocannabinoids inhibit colorectal carcinoma cell proliferation in vitro. In this paper, we investigated the involvement of endocannabinoids on the formation of aberrant crypt foci (ACF, earliest preneoplastic lesions) in the colon mouse in vivo. ACF were induced by azoxymethane (AOM); fatty acid amide hydrolase (FAAH) and cannabinoid receptor messenger ribonucleic acid (mRNA) levels were analyzed by the quantitative reverse transcription polymerase chain reaction (RT-PCR); endocannabinoid levels were measured by liquid chromatography-mass spectrometry; caspase-3 and caspase-9 expressions were measured by Western blot analysis. Colonic ACF formation after AOM administration was associated with increased levels of 2-arachidonoylglycerol (with no changes in FAAH and cannabinoid receptor mRNA levels) and reduction in cleaved caspase-3 and caspase-9 expression. The FAAH inhibitor N-arachidonoylserotonin increased colon endocannabinoid levels, reduced ACF formation, and partially normalized cleaved caspase-3 (but not caspase-9) expression. Notably, N-arachidonoylserotonin completely prevented the formation of ACF with four or more crypts, which have been show to be best correlated with final tumor incidence. The effect of N-arachidonoylserotonin on ACF formation was mimicked by the cannabinoid receptor agonist HU-210. No differences in ACF formation were observed between CB(1) receptor-deficient and wild-type mice. It is concluded that pharmacological enhancement of endocannabinoid levels (through inhibition of endocannabinoid hydrolysis) reduces the development of precancerous lesions in the mouse colon. The protective effect appears to involve caspase-3 (but not caspase-9) activation.
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PMID:Increased endocannabinoid levels reduce the development of precancerous lesions in the mouse colon. 1782 81

The maternal use of cannabis during pregnancy results in a number of cognitive deficits in the offspring that persist into adulthood. The endocannabinoid system has a role to play in neurodevelopmental processes such as neurogenesis, migration and synaptogenesis. However, exposure to phytocannabinoids, such as Delta(9)-tetrahydrocannabinol, during gestation may interfere with these events to cause abnormal patterns of neuronal wiring and subsequent cognitive impairments. Aberrant cell death evoked by Delta(9)-tetrahydrocannabinol may also contribute to cognitive deficits and in cultured neurones Delta(9)-tetrahydrocannabinol induces apoptosis via the CB(1) cannabinoid receptor. In this study we report that Delta(9)-tetrahydrocannabinol (5-50 microM) activates the stress-activated protein kinase, c-jun N-terminal kinase, and the pro-apoptotic protease, caspase-3, in in vitro cerebral cortical slices obtained from the neonatal rat brain. The proclivity of Delta(9)-tetrahydrocannabinol to impact on these pro-apoptotic signalling molecules was not observed in in vitro cortical slices obtained from the adult rat brain. In vivo, subcutaneous administration of Delta(9)-tetrahydrocannabinol (1-30 mg/kg) activated c-jun N-terminal kinase, caspase-3 and cathepsin-D, and induced DNA fragmentation in the cerebral cortex of neonatal rats. In contrast, in vivo administration of Delta(9)-tetrahydrocannabinol to adult rats was not associated with the apoptotic pathway in the cerebral cortex. The data provide evidence which supports the hypothesis that the neonatal rat brain is more vulnerable to the neurotoxic influence of Delta(9)-tetrahydrocannabinol, suggesting that the cognitive deficits that are observed in humans exposed to marijuana during gestation may be due, in part, to abnormal engagement of the apoptotic cascade during brain development.
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PMID:A comparison of the apoptotic effect of Delta(9)-tetrahydrocannabinol in the neonatal and adult rat cerebral cortex. 1788 22

Macrophage apoptosis is an important process in the pathophysiology of atherosclerosis. Oxidized low-density lipoproteins (OxLDL) are a major component of lesions and potently induce macrophage apoptosis. Cannabinoid receptor 2 (CB2), the predominant macrophage cannabinoid receptor, modulates several macrophage processes associated with ongoing atherosclerosis; however, the role of CB2 in macrophage apoptosis is unknown. To determine if CB2 influences a macrophage apoptotic pathway relevant to atherosclerosis, we examined the effect of CB2 deficiency on OxLDL-induced macrophage apoptosis. In situ terminal transferase-mediated dUTP nick end labeling (TUNEL) analysis of resident peritoneal macrophages detected significantly fewer apoptotic CB2(-/-) macrophages than CB2(+/+) macrophages after incubation with OxLDL (27.9 +/- 4.7% vs. 61.9 +/- 8.5%, P < 0.001) or 7-ketocholesterol (7KC) (18.9 +/- 10.5% vs. 54.1 +/- 6.9%, P < 0.001), an oxysterol component of OxLDL. Caspase-3 activity; proteolytic conversion of procaspase-3; and cleavage of a caspase-3 substrate, PARP, were also diminished in 7KC-treated CB2(-/-) macrophages. Furthermore, the deactivation of the prosurvival kinase, Akt, in response to 7KC was impaired in CB2(-/-) macrophages. These results suggest that CB2 expression increases the susceptibility of macrophages to OxLDL-induced apoptosis, in part, by modulating the effect of oxysterols on the Akt survival pathway and that CB2 may influence atherosclerosis by modulating lesional macrophage apoptosis.
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PMID:Cannabinoid (CB2) receptor deficiency reduces the susceptibility of macrophages to oxidized LDL/oxysterol-induced apoptosis. 1861 16

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.
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PMID:The CB1/CB2 receptor agonist WIN-55,212-2 reduces viability of human Kaposi's sarcoma cells in vitro. 1953 19


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