scholarly journals The FGF receptor uses the endocannabinoid signaling system to couple to an axonal growth response

2003 ◽  
Vol 160 (4) ◽  
pp. 481-486 ◽  
Author(s):  
Emma-Jane Williams ◽  
Frank S. Walsh ◽  
Patrick Doherty
Keyword(s):  
Lipase Activity ◽  
Growth Response ◽  
Cannabinoid Receptor ◽  
Calcium Influx ◽  
Axonal Growth ◽  
Receptor Activation ◽  
Cb1 Receptor ◽  
Neurotrophin Receptor ◽  
Fgf Receptor ◽  
Hydrolysis Of

Akey role for DAG lipase activity in the control of axonal growth and guidance in vitro and in vivo has been established. For example, DAG lipase activity is required for FGF-stimulated calcium influx into neuronal growth cones, and this response is both necessary and sufficient for an axonal growth response. The mechanism that couples the hydrolysis of DAG to the calcium response is not known. The initial hydrolysis of DAG at the sn-1 position (by DAG lipase) will generate 2-arachidonylglycerol, and this molecule is well established as an endogenous cannabinoid receptor agonist in the brain. In the present paper, we show that in rat cerebellar granule neurons, CB1 cannabinoid receptor antagonists inhibit axonal growth responses stimulated by N-cadherin and FGF2. Furthermore, three CB1 receptor agonists mimic the N-cadherin/FGF2 response at a step downstream from FGF receptor activation, but upstream from calcium influx into cells. In contrast, we could find no evidence for the CB1 receptor coupling the TrkB neurotrophin receptor to an axonal growth response in the same neurons. The observation that the CB1 receptor can couple the activated FGF receptor to an axonal growth response raises novel therapeutic opportunities.

scholarly journals Marijuana smoke induces severe pulmonary hyperresponsiveness, inflammation, and emphysema in a predictive mouse model not via CB1 receptor activation

2017 ◽  
Vol 313 (2) ◽  
pp. L267-L277 ◽  
Author(s):  
Z. Helyes ◽  
Á. Kemény ◽  
K. Csekő ◽  
É. Szőke ◽  
K. Elekes ◽  
...  
Keyword(s):  
Tobacco Smoke ◽  
Airway Hyperresponsiveness ◽  
Inflammatory Cell ◽  
Cannabinoid Receptor ◽  
Receptor Activation ◽  
Cb1 Receptor ◽  
Whole Body ◽  
Myeloperoxidase Activity ◽  
Tissue Destruction ◽  
Cell Hyperplasia

Sporadic clinical reports suggested that marijuana smoking induces spontaneous pneumothorax, but no animal models were available to validate these observations and to study the underlying mechanisms. Therefore, we performed a systematic study in CD1 mice as a predictive animal model and assessed the pathophysiological alterations in response to 4-mo-long whole body marijuana smoke with integrative methodologies in comparison with tobacco smoke. Bronchial responsiveness was measured with unrestrained whole body plethysmography, cell profile in the bronchoalveolar lavage fluid with flow cytometry, myeloperoxidase activity with spectrophotometry, inflammatory cytokines with ELISA, and histopathological alterations with light microscopy. Daily marijuana inhalation evoked severe bronchial hyperreactivity after a week. Characteristic perivascular/peribronchial edema, atelectasis, apical emphysema, and neutrophil and macrophage infiltration developed after 1 mo of marijuana smoking; lymphocyte accumulation after 2 mo; macrophage-like giant cells, irregular or destroyed bronchial mucosa, goblet cell hyperplasia after 3 mo; and severe atelectasis, emphysema, obstructed or damaged bronchioles, and endothelial proliferation at 4 mo. Myeloperoxidase activity, inflammatory cell, and cytokine profile correlated with these changes. Airway hyperresponsiveness and inflammation were not altered in mice lacking the CB1 cannabinoid receptor. In comparison, tobacco smoke induced hyperresponsiveness after 2 mo and significantly later caused inflammatory cell infiltration/activation with only mild emphysema. We provide the first systematic and comparative experimental evidence that marijuana causes severe airway hyperresponsiveness, inflammation, tissue destruction, and emphysema, which are not mediated by the CB1 receptor.

Inhibition of Inflammatory Hyperalgesia by Activation of Peripheral CB2Cannabinoid Receptors

2003 ◽  
Vol 99 (4) ◽  
pp. 955-960 ◽  
Author(s):  
Aline Quartilho ◽  
Heriberto P. Mata ◽  
Mohab M. Ibrahim ◽  
Todd W. Vanderah ◽  
Frank Porreca ◽  
...  
Keyword(s):  
Cannabinoid Receptor ◽  
Thermal Hyperalgesia ◽  
Receptor Activation ◽  
Cb1 Receptor ◽  
Cb2 Receptor ◽  
Inflammatory Hyperalgesia ◽  
Selective Antagonist ◽  
Receptor Agonists ◽  
Cb2 Receptors ◽  
Cns Effects

Background Cannabinoid receptor agonists inhibit inflammatory hyperalgesia in animal models. Nonselective cannabinoid receptor agonists also produce central nervous system (CNS) side effects. Agonists selective for CB2 cannabinoid receptors, which are not found in the CNS, do not produce the CNS effects typical of nonselective cannabinoid receptor agonists but do inhibit acute nociception. The authors used the CB2 receptor-selective agonist AM1241 to test the hypothesis that selective activation of peripheral CB2 receptors inhibits inflammatory hyperalgesia. Methods Rats were injected in the hind paw with carrageenan or capsaicin. Paw withdrawal latencies were measured using a focused thermal stimulus. The effects of peripheral CB2 receptor activation were determined by using local injection of AM1241. CB2 receptor mediation of the actions of AM1241 was shown by using the CB2 receptor-selective antagonist AM630 and the CB1 receptor-selective antagonist AM251. Results AM1241 fully reversed carrageenan-induced inflammatory thermal hyperalgesia when injected into the inflamed paw. In contrast, AM1241 injected into the contralateral paw had no effect, showing that its effects were local. AM1241 also reversed the local edema produced by hind paw carrageenan injection. The effects of AM1241 were reversed by the CB2 receptor-selective antagonist AM630, but not by the CB1 receptor-selective antagonist AM251. AM1241 also inhibited flinching and thermal hyperalgesia produced by hind paw capsaicin injection. Conclusions Local, peripheral CB2 receptor activation inhibits inflammation and inflammatory hyperalgesia. These results suggest that peripheral CB2 receptors may be an appropriate target for eliciting relief of inflammatory pain without the CNS effects of nonselective cannabinoid receptor agonists.

scholarly journals CB1 Cannabinoid Receptor Signaling and Biased Signaling

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5413
Author(s):  
Luciana M. Leo ◽  
Mary E. Abood
Keyword(s):  
Adverse Effects ◽  
G Protein ◽  
Conformational Changes ◽  
Cannabinoid Receptor ◽  
Therapeutic Potential ◽  
Receptor Activation ◽  
Cb1 Receptor ◽  
Cb1 Cannabinoid Receptor ◽  
Biased Signaling ◽  
G Protein Coupled

The CB1 cannabinoid receptor is a G-protein coupled receptor highly expressed throughout the central nervous system that is a promising target for the treatment of various disorders, including anxiety, pain, and neurodegeneration. Despite the wide therapeutic potential of CB1, the development of drug candidates is hindered by adverse effects, rapid tolerance development, and abuse potential. Ligands that produce biased signaling—the preferential activation of a signaling transducer in detriment of another—have been proposed as a strategy to dissociate therapeutic and adverse effects for a variety of G-protein coupled receptors. However, biased signaling at the CB1 receptor is poorly understood due to a lack of strongly biased agonists. Here, we review studies that have investigated the biased signaling profile of classical cannabinoid agonists and allosteric ligands, searching for a potential therapeutic advantage of CB1 biased signaling in different pathological states. Agonist and antagonist bound structures of CB1 and proposed mechanisms of action of biased allosteric modulators are used to discuss a putative molecular mechanism for CB1 receptor activation and biased signaling. Current studies suggest that allosteric binding sites on CB1 can be explored to yield biased ligands that favor or hinder conformational changes important for biased signaling.

scholarly journals Contribution of Hypothermia and CB1 Receptor Activation to Protective Effects of TAK-937, a Cannabinoid Receptor Agonist, in Rat Transient MCAO Model

PLoS ONE ◽  
2012 ◽  
Vol 7 (7) ◽  
pp. e40889 ◽  
Author(s):  
Noriko Suzuki ◽  
Motohisa Suzuki ◽  
Kazuhiro Hamajo ◽  
Koji Murakami ◽  
Tetsuya Tsukamoto ◽  
...  
Keyword(s):  
Receptor Agonist ◽  
Cannabinoid Receptor ◽  
Receptor Activation ◽  
Cb1 Receptor ◽  
Protective Effects

Cannabinoids Modulate the P-Type High-Voltage-Activated Calcium Currents in Purkinje Neurons

2006 ◽  
Vol 96 (3) ◽  
pp. 1267-1277 ◽  
Author(s):  
Alexander Fisyunov ◽  
Vera Tsintsadze ◽  
Rogier Min ◽  
Nail Burnashev ◽  
Natalia Lozovaya
Keyword(s):  
Calcium Influx ◽  
Direct Action ◽  
Similar Efficacy ◽  
Receptor Activation ◽  
Cb1 Receptor ◽  
Calcium Currents ◽  
Purkinje Neurons ◽  
Presynaptic Calcium ◽  
Central Synapses ◽  
P Type

Endocannabinoids released by postsynaptic cells inhibit neurotransmitter release in many central synapses by activating presynaptic cannabinoid CB1 receptors. In particular, in the cerebellum, endocannabinoids inhibit synaptic transmission at granule cell to Purkinje cell synapses by modulating presynaptic calcium influx via N-, P/Q-, and R-type calcium channels. Using whole cell patch-clamp techniques, we show that in addition to this presynaptic action, both synthetic and endogenous cannabinoids inhibit P-type calcium currents in isolated rat Purkinje neurons independent of CB1 receptor activation. The IC50 for the anandamide (AEA)-induced inhibition of P-current peak amplitude was 1.04 ± 0.04 μM. In addition, we demonstrate that all the tested cannabinoids in a physiologically relevant range of concentrations strongly accelerate inactivation of P currents. The effects of AEA cannot be attributed to the metabolism of AEA because a nonhydrolyzing analogue of AEA, methanandamide inhibited P-type currents with a similar efficacy. All effects of cannabinoids on P-type Ca2+ currents were insensitive to antagonists of CB1 cannabinoid or vanilloid TRPV1 receptors. In cerebellar slices, WIN 55,212–2 significantly affected spontaneous firing of Purkinje neurons in the presence of CB1 receptor antagonist, in a manner similar to that of a specific P-type channel antagonist, indicating a possible functional implication of the direct effects of cannabinoids on P current. Taken together these findings demonstrate a functionally important direct action of cannabinoids on P-type calcium currents.

Cannabinoid Receptor Modulation of Synapses Received by Cerebellar Purkinje Cells

2000 ◽  
Vol 83 (3) ◽  
pp. 1167-1180 ◽  
Author(s):  
Kanji A. Takahashi ◽  
David J. Linden
Keyword(s):  
Neurotransmitter Release ◽  
Cannabinoid Receptors ◽  
Cannabinoid Receptor ◽  
Receptor Activation ◽  
Cb1 Receptor ◽  
Vesicle Release ◽  
Voltage Gated ◽  
Postsynaptic Currents ◽  
Voltage Gated Channels ◽  
Release Processes

The high density of cannabinoid receptors in the cerebellum and the degradation of motor coordination produced by cannabinoid intoxication suggest that synaptic transmission in the cerebellum may be strongly regulated by cannabinoid receptors. Therefore the effects of exogenous cannabinoids on synapses received by Purkinje cells were investigated in rat cerebellar slices. Parallel fiber–evoked (PF) excitatory postsynaptic currents (EPSCs) were strongly inhibited by bath application of the cannabinoid receptor agonist WIN 55212-2 (5 μM, 12% of baseline EPSC amplitude). This effect was completely blocked by the cannabinoid CB1 receptor antagonist SR 141716. It is unlikely that this was the result of alterations in axonal excitability because fiber volley velocity and kinetics were unchanged and a cannabinoid-induced decrease in fiber volley amplitude was very minor (93% of baseline). WIN 55212-2 had no effect on the amplitude or frequency of spontaneously occurring miniature EPSCs (mEPSCs), suggesting that the effect of CB1 receptor activation on PF EPSCs was presynaptically expressed, but giving no evidence for modulation of release processes after Ca2+influx. EPSCs evoked by climbing fiber (CF) stimulation were less powerfully attenuated by WIN 55212-2 (5 μM, 74% of baseline). Large, action potential–dependent, spontaneously occurring inhibitory postsynaptic currents (sIPSCs) were either severely reduced in amplitude (<25% of baseline) or eliminated. Miniature IPSCs (mIPSCs) were reduced in frequency (52% of baseline) but not in amplitude, demonstrating suppression of presynaptic vesicle release processes after Ca2+ influx and suggesting an absence of postsynaptic modulation. The decrease in mIPSC frequency was not large enough to account for the decrease in sIPSC amplitude, suggesting that presynaptic voltage-gated channel modulation was also involved. Thus, while CB1 receptor activation reduced neurotransmitter release at all major classes of Purkinje cell synapses, this was not accomplished by a single molecular mechanism. At excitatory synapses, cannabinoid suppression of neurotransmitter release was mediated by modulation of voltage-gated channels in the presynaptic axon terminal. At inhibitory synapses, in addition to modulation of presynaptic voltage-gated channels, suppression of the downstream vesicle release machinery also played a large role.

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