Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The endogenous cannabimimetic anandamide is hydrolyzed by a fatty acid amide hydrolase to yield arachidonic acid and ethanolamine. In the present study, the regional distribution of the activity and its sensitivity to inhibition by the enantiomers of ibuprofen, ketorolac, and flurbiprofen has been investigated. The rate of [3H]anandamide hydrolysis was found in both 7-week-old and 90-week-old rats to be in the order hippocampus > cerebral cortex > cerebellum > striatum approximately midbrain, with higher rates of hydrolysis for the 7-week-old rats than for the 90-week-old rats. In whole brain (minus cerebellum), the R(-)-enantiomer of ibuprofen was a mixed-type inhibitor of anandamide hydrolysis and was approximately 2-3 times more potent than the S(+)-enantiomer, IC50 values of 230 and 750 microM, respectively, being found. A similar pattern of inhibition of anandamide hydrolysis was seen when intact C6 rat glioma cells were used. Ketorolac inhibited rat brain anandamide hydrolysis, with IC50 values of 50, 440, and 80 microM being found for the R-, S-, and R,S-forms, respectively. The IC50 value for R-flurbiprofen (60 microM) was similar to the IC50 value for the S-enantiomer (50 microM). These data demonstrate that there is no dramatic enantiomeric selectivity of NSAID compounds as inhibitors of fatty acid amide hydrolase enzyme(s) responsible for the hydrolysis of anandamide. The enantiomers of flurbiprofen and R-ketorolac are the most potent NSAID inhibitors of fatty acid amide hydrolase yet reported.
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PMID:Inhibition of anandamide hydrolysis by the enantiomers of ibuprofen, ketorolac, and flurbiprofen. 998 26

N-Arachidonoylethanolamine (AEA) is a proposed endogenous ligand of the central cannabinoid receptor (CB1). Previous studies indicate that AEA is translocated across membranes via a process that has the characteristics of carrier-mediated facilitated diffusion. To date, studies of this mechanism have relied on [(3)H]AEA as a substrate for the carrier. We have synthesized an analog of AEA, SKM 4-45-1, that is nonfluorescent in the extracellular environment. When SKM 4-45-1 is exposed to intracellular esterases, it is de-esterified and becomes fluorescent. We have carried out studies to demonstrate that SKM 4-45-1 accumulation in cells occurs via the AEA carrier. SKM 4-45-1 is accumulated by both cerebellar granule cells and C6 glioma cells. Uptake of SKM 4-45-1 into C6 glioma is inhibited by AEA (IC(50)=53.8 +/- 1.8 microM), arachidonoyl-3-aminopyridine amide (IC(50)=10.1 +/- 1.4 microM), and arachidonoyl-4-hydroxyanilineamide (IC(50)=6.1 +/- 1.3 microM), all of which also inhibit [(3)H]AEA accumulation. Conversely, [(3)H]AEA accumulation by cerebellar granule cells is inhibited by SKM 4-45-1 with an IC(50) of 7.8 +/- 1. 3 microM. SKM 4-45-1 is neither a substrate nor inhibitor of fatty acid amide hydrolase, an enzyme that catabolizes AEA. SKM 4-45-1 does not bind the CB1 cannabinoid receptor at concentrations <10 microM. In summary, the cellular accumulation of SKM 4-45-1 occurs via the same pathway as AEA uptake and provides an alternative substrate for the study of this important cellular process.
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PMID:Synthesis and characterization of a fluorescent substrate for the N-arachidonoylethanolamine (anandamide) transmembrane carrier. 1073 81

We reported previously that synthetic amides of polyunsaturated fatty acids with bioactive amines can result in substances that interact with proteins of the endogenous cannabinoid system (ECS). Here we synthesized a series of N-acyl-dopamines (NADAs) and studied their effects on the anandamide membrane transporter, the anandamide amidohydrolase (fatty acid amide hydrolase, FAAH) and the two cannabinoid receptor subtypes, CB(1) and CB(2). NADAs competitively inhibited FAAH from N18TG2 cells (IC(50)=19-100 microM), as well as the binding of the selective CB(1) receptor ligand, [(3)H]SR141716A, to rat brain membranes (K(i)=250-3900 nM). The arachidonoyl (20:4 omega 6), eicosapentaenoyl (20:5 omega 3), docosapentaenoyl (22:5 omega 3), alpha-linolenoyl (18:3 omega 3) and pinolenoyl (5c,9c,12c 18:3 omega 6) homologues were also found to inhibit the anandamide membrane transporter in RBL-2H3 basophilic leukaemia and C6 glioma cells (IC(50)=17.5-33 microM). NADAs did not inhibit the binding of the CB(1)/CB(2) receptor ligand, [(3)H]WIN55,212-2, to rat spleen membranes (K(i)>10 microM). N-arachidonyl-dopamine (AA-DA) exhibited 40-fold selectivity for CB(1) (K(i)=250 nM) over CB(2) receptors, and N-docosapentaenoyl-dopamine exhibited 4-fold selectivity for the anandamide transporter over FAAH. AA-DA (0.1-10 microM) did not displace D1 and D2 dopamine-receptor high-affinity ligands from rat brain membranes, thus suggesting that this compound has little affinity for these receptors. AA-DA was more potent and efficacious than anandamide as a CB(1) agonist, as assessed by measuring the stimulatory effect on intracellular Ca(2+) mobilization in undifferentiated N18TG2 neuroblastoma cells. This effect of AA-DA was counteracted by the CB(1) antagonist SR141716A. AA-DA behaved as a CB(1) agonist in vivo by inducing hypothermia, hypo-locomotion, catalepsy and analgesia in mice (1-10 mg/kg). Finally, AA-DA potently inhibited (IC(50)=0.25 microM) the proliferation of human breast MCF-7 cancer cells, thus behaving like other CB(1) agonists. Also this effect was counteracted by SR141716A but not by the D2 antagonist haloperidol. We conclude that NADAs, and AA-DA in particular, may be novel and useful probes for the study of the ECS.
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PMID:N-acyl-dopamines: novel synthetic CB(1) cannabinoid-receptor ligands and inhibitors of anandamide inactivation with cannabimimetic activity in vitro and in vivo. 1104 39

Stearoylethanolamide (SEA) is present in human, rat and mouse brain in amounts comparable with those of the endocannabinoid anandamide (arachidonoylethanolamide; AEA). Yet, the biological activity of SEA has never been investigated. We synthesized unlabelled and radiolabelled SEA to investigate its binding, degradation and biological activity in rat C6 glioma cells. We report that SEA binds to a specific site distinct from known cannabinoid or vanilloid receptors, and that AEA and capsazepine partly (approx. 50%) antagonized this binding. Treatment of C6 cells with SEA inhibits cellular nitric oxide synthase and does not affect adenylate cyclase, whereas treatment with cannabinoid type 1 agonist 2-arachidonoylglycerol activates the former enzyme and inhibits the latter. C6 cells also have a specific SEA membrane transporter, which is inhibited by NO, and a fatty acid amide hydrolase capable of cleaving SEA. In these cells, SEA shows pro-apoptotic activity, due to elevation of intracellular calcium, activation of the arachidonate cascade and mitochondrial uncoupling. NO further enhances SEA-induced apoptosis. Moreover, the cannabinoid type 1 receptor-mediated decrease in cAMP induced by AEA in C6 cells is potentiated by SEA, suggesting that this compound also has an 'entourage' effect. Taken together, this study shows that SEA is an endocannabinoid-like compound which binds to and is transported by new components of the endocannabinoid system. It seems noteworthy that degradation and pro-apoptotic activity of SEA are regulated by NO in a way opposite to that reported for AEA.
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PMID:Binding, degradation and apoptotic activity of stearoylethanolamide in rat C6 glioma cells. 1201 Jan 21

It has previously been shown that the endocannabinoids anandamide and 2-arachidonoylglycerol (2-AG) inhibit the proliferation of C6 glioma cells in a manner that can be prevented by a combination of capsazepine (Caps) and cannabinoid (CB) receptor antagonists. It is not clear whether the effect of 2-AG is due to the compound itself, due to the rearrangement to form 1-arachidonoylglycerol (1-AG) or due to a metabolite. Here, it was found that the effects of 2-AG can be mimicked with 1-AG, both in terms of its potency and sensitivity to antagonism by Caps and CB receptor antagonists. In order to determine whether the effect of Caps could be ascribed to actions upon vanilloid receptors, the effect of a more selective vanilloid receptor antagonist, SB366791 was investigated. This compound inhibited capsaicin-induced Ca(2+) influx into rVR1-HEK293 cells with a pK(B) value of 6.8+/-0.3. The combination of SB366791 and CB receptor antagonists reduced the antiproliferative effect of 1-AG, confirming a vanilloid receptor component in its action. 1-AG, however, showed no direct effect on Ca(2+) influx into rVR1-HEK293 cells indicative of an indirect effect upon vanilloid receptors. Identification of the mechanism involved was hampered by a large inter-experimental variation in the sensitivity of the cells to the antiproliferative effects of 1-AG. A variation was also seen with anandamide, which was not a solubility issue, since its water soluble phosphate ester showed the same variability. In contrast, the sensitivity to methanandamide, which was not sensitive to antagonism by the combination of Caps and CB receptor antagonists, but has similar physicochemical properties to anandamide, did not vary between experiments. This variation greatly reduces the utility of these cells as a model system for the study of the antiproliferative effects of anandamide. Nevertheless, it was possible to conclude that the antiproliferative effects of anandamide were not solely mediated by either its hydrolysis to produce arachidonic acid or its CB receptor-mediated activation of phospholipase A(2) since palmitoyltrifluoromethyl ketone did not prevent the response to anandamide. The same result was seen with the fatty acid amide hydrolase inhibitor palmitoylethylamide. Increasing intracellular arachidonic acid by administration of arachidonic acid methyl ester did not affect cell proliferation, and the modest antiproliferative effect of umbelliferyl arachidonate was not prevented by a combination of Caps and CB receptor antagonists.
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PMID:Inhibition of C6 glioma cell proliferation by anandamide, 1-arachidonoylglycerol, and by a water soluble phosphate ester of anandamide: variability in response and involvement of arachidonic acid. 1294 56

There is considerable debate at present as to whether the uptake of anandamide (AEA) into cells is by a facilitated transport process or by passive diffusion driven by fatty acid amide hydrolase (FAAH). The possibility that both processes occur, but to different extents depending upon the cell type used, has been difficult to investigate pharmacologically since available compounds show little selectivity between inhibition of AEA uptake and inhibition of FAAH. Recently, three compounds, UCM707 [N-(Fur-3-ylmethyl)arachidonamide], OMDM-1 and OMDM-2 [the 1'-(S)- and 1'-(R)-enantiomers of the 1'-4-hydroxybenzoyl analogue of oleoylethanolamide], selective for the uptake process, have been described and we have used these compounds, together with AM404 [(N-(4-hydroxyphenyl) arachidonoyl amide)] and VDM11 [(5Z,8Z,11Z,14Z)-N-(4-Hydroxy-2-methylphenyl)-5,8,11,14-eicosatetraenamide]), with the initial aim of determining which mechanism of uptake predominates in C6 glioma and RBL-2H3 cells. AM404 and VDM11 were both found to decrease the uptake of 2 microM AEA into cells (IC50 values 6-11 microM), but they also inhibited rat brain FAAH (IC50 values 1-6 microM). However, when using a different FAAH assay protocol, VDM11 was a much less potent FAAH inhibitor (IC50>50 microM) regardless of the cell type and animal species used. In contrast, we confirmed that UCM707, OMDM-1 and OMDM-2 were weak inhibitors of FAAH (IC50 values >50 microM) under all conditions used. However, their potency as inhibitors of AEA cellular accumulation appears to be largely dependent on the cell type and assay conditions used. In particular, the potency of UCM707 (IC50 value > or =25 microM) was considerably lower than the submicromolar potency previously reported for U937 cells. It is concluded that the cause/effect relationship between AEA uptake and hydrolysis cannot be investigated uniquely by using supposedly selective inhibitors of each process.
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PMID:Selective inhibition of anandamide cellular uptake versus enzymatic hydrolysis--a difficult issue to handle. 1514 99

N-Arachidonoyl (AA) derivatives of amino acids (glycine, phenylalanine, proline, valine, gamma-amino butyric acid (GABA), dihydroxyphenylalanine, tyrosine, tryptophan, and alanine) and peptides (Semax, MEHFPGP, and PGP) were synthesized in order to study the biological properties of acylamino acids. The mass spectra of all the compounds at atmospheric pressure electrospray ionization display the most intense peaks of protonated molecular ions; the detection limits for these compounds are 10 fmol per sample. AA-Gly showed the highest inhibitory activity toward fatty acid amide hydrolase from rat brain (IC50 6.5 microM) among all the acylamino acids studied. AA-Phe, AA-Tyr, and AA-GABA exhibited a weak but detectable inhibitory effect (IC50 55, 60, and 50 microM, respectively). The acylated amino acids themselves, except for AA-Gly, were stable to the hydrolysis by this enzyme. All the arachidonoylamino acids inhibited cabbage phospholipase D to various degrees; AA-GABA and AA-Phe proved to be the most active (IC50 20 and 27 microM, respectively). Attempts to detect the biosynthesis of AA-Tyr in homogenates of rat liver and nerve tissue showed no formation in vitro of either this acylamino acid or AA-dopamine and AA-Phe, the products of its metabolism. The highest contents of these metabolites were detected in liver homogenate and in the brain homogenate, respectively. Acylamino acids exert no cytotoxic effect toward the glioma C6 cells. It was shown that N-acylation of Semax with arachidonic acid results in enhancement of its hydrolytic stability and increases its affinity for the sites of specific binding in rat cerebellum membranes. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2006, vol. 32, no. 3; see also http://www.maik.ru.
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PMID:[Arachidonoyl amino acids and arachidonoyl peptides: synthesis and properties]. 1680 68

Inhibitors of the enzyme fatty acid amide hydrolase (FAAH), the principal enzyme involved in the metabolism of the endogenous cannabinoid anandamide, have potential utility in the treatment of disorders including inflammation and inflammatory pain. The carbamate compound URB597 (3'-carbamoyl-biphenyl-3-yl-cyclohexylcarbamate) potently and selectively inhibits FAAH by forming a covalent bond with a key serine residue of the enzyme. Little is known as to the pH dependency of this inhibition. Using a preincubation time of 10min, URB597 inhibited rat brain anandamide hydrolysis with pI(50) values of 7.19+/-0.02 and 7.75+/-0.06 at pH 6 and 8, respectively. The inhibition was time-dependent, and second order rate constants of approximately 0.15x10(6)M(-1)min(-1) (pH 6) and approximately 1.2x10(6)M(-1)min(-1) (pH 8) could be estimated. In intact C6 glioma cells and using a preincubation time of 10min, URB597 inhibited the hydrolysis of 250nM [(3)H]AEA hydrolysis with pI(50) values of 5.58+/-0.07 and 6.45+/-0.07 at extracellular pH values of 6 and 8, respectively. Since tissue pH is affected by inflammation, these data would suggest that the pH selectivity of the inhibition can contribute to the potency of the compound in vivo.
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PMID:The potency of the fatty acid amide hydrolase inhibitor URB597 is dependent upon the assay pH. 1699 68

Recently, we have shown that treatment of rat C6 glioma cells with the raft disruptor methyl-beta-cyclodextrin (MCD) doubles the binding of anandamide (AEA) to type-1 cannabinoid receptors (CB1R), followed by CB1R-dependent signaling via adenylate cyclase and p42/p44 MAPK activity. In the present study, we investigated whether type-2 cannabinoid receptors (CB2R), widely expressed in immune cells, also are modulated by MCD. We show that treatment of human DAUDI leukemia cells with MCD does not affect AEA binding to CB2R, and that receptor activation triggers similar [35S]guanosine-5'-O-(3-thiotriphosphate) binding in MCD-treated and control cells, similar adenylate cyclase and MAPK activity, and similar MAPK-dependent protection against apoptosis. The other AEA-binding receptor transient receptor potential channel vanilloid receptor subunit 1, the AEA synthetase N-acyl-phosphatidylethanolamine-phospholipase D, and the AEA hydrolase fatty acid amide hydrolase were not affected by MCD, whereas the AEA membrane transporter was inhibited (approximately 55%) compared with controls. Furthermore, neither diacylglycerol lipase nor monoacylglycerol lipase, which respectively synthesize and degrade 2-arachidonoylglycerol, were affected by MCD in DAUDI or C6 cells, whereas the transport of 2-arachidonoylglycerol was reduced to approximately 50%. Instead, membrane cholesterol enrichment almost doubled the uptake of AEA and 2-arachidonoylglycerol in both cell types. Finally, transfection experiments with human U937 immune cells, and the use of primary cells expressing CB1R or CB2R, ruled out that the cellular environment could account per se for the different modulation of CB receptor subtypes by MCD. In conclusion, the present data demonstrate that lipid rafts control CB1R, but not CB2R, and endocannabinoid transport in immune and neuronal cells.
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PMID:Effect of lipid rafts on Cb2 receptor signaling and 2-arachidonoyl-glycerol metabolism in human immune cells. 1701 79

There is evidence in the literature that the nonsteroidal anti-inflammatory drugs indomethacin and ibuprofen can interact with the cannabinoid system both in vitro and in vivo. In the present study, a series of analogues of ibuprofen and indomethacin have been investigated with respect to their ability to inhibit fatty acid amide hydrolase, the enzyme responsible for the hydrolysis of the endogenous cannabinoid anandamide. Of the fourteen compounds tested, the 6-methyl-pyridin-2-yl analogue of ibuprofen ("ibu-am5") was selected for further study. This compound inhibited rat brain anandamide hydrolysis in a non-competitive manner, with IC50 values of 4.7 and 2.5 microM being found at pH 6 and 8, respectively. By comparison, the IC50 values for ibuprofen were 130 and 750 microM at pH 6 and 8, respectively. There was no measurable N-acylethanolamine hydrolyzing acid amidase activity in rat brain membrane preparations. In intact C6 glioma cells, ibu-am5 inhibited the hydrolysis of anandamide with an IC50 value of 1.2 microM. There was little difference in the potencies of ibu-am5 and ibuprofen towards cyclooxygenase-1 and -2 enzymes, and neither compound inhibited the activity of monoacylglycerol lipase. Ibu-am5 inhibited the binding of [3H]-CP55,940 to rat brain CB1 and human CB2 cannabinoid receptors more potently than ibuprofen, but the increase in potency was less than the corresponding increase in potency seen for inhibition of FAAH activity. It is concluded that ibu-am5 is an analogue of ibuprofen with a greater potency towards fatty acid amide hydrolase but with a similar cyclooxygenase inhibitory profile, and may be useful for the study of the therapeutic potential of combined fatty acid amide hydrolase-cyclooxygenase inhibitors.
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PMID:Inhibition of fatty acid amide hydrolase, a key endocannabinoid metabolizing enzyme, by analogues of ibuprofen and indomethacin. 1739 26


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