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ABSTRACT Objective To verify the involvement of the endocannabinoid system in the immunomodulatory profile of stem cells from human exfoliated deciduous teeth, in the presence or absence of TNF-α, and agonist and antagonists of CB1 and CB2. Methods Stem cells from human exfoliated deciduous teeth were cultured in the presence or absence of an agonist, anandamide, and two antagonists, AM251 and SR144528, of CB1 and CB2 receptors, with or without TNF-α stimulation. For analysis of immunomodulation, surface molecules linked to immunomodulation, namely human leukocyte antigen-DR isotype (HLA-DR), and programmed death ligands 1 (PD-L1) and 2 (PD-L2) were measured using flow cytometry. Results The inhibition of endocannabinoid receptors together with the proinflammatory effect of TNF-α resulted in increased HLA-DR expression in stem cells from human exfoliated deciduous teeth, as well as, in these cells acquiring an anti-inflammatory profile by enhancing the expression of PD-L1 and PD-L2. Conclusion Stem cells from human exfoliated deciduous teeth respond to the endocannabinoid system and TNF-α by altering key immune response molecules.
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Epilepsy,a group of chronic neurological disorders characterized by spontaneous and recurrent seizures and learning and memory impairments,results in transient brain dysfunction due to sudden abnormal discharge of brain neurons.The pathogenesis of epilepsy is very complicated and has not yet been fully elucidated.The imbalance between excitatory glutamate and inhibitory gamma-aminobutyric acid (GABA) neurotransmitters in the central nervous system and changes in ionic functions of N-methyl-D-aspartate receptors directly induce epileptic seizures.The endocannabinoid system plays an important role in retrograde synaptic transmission and exerts the anti-epileptic effect in cannabinoid receptor 1 (CBR1) dependent manner by regulating the synaptic transmission of glutamatergic and GABAergic neurons and homeostatsis of ionic channel function.Elucidating the specific mechanism of action of CBR1 signaling pathway in epilepsy,can provide an effective theoretical basis and novel drug's target for clinical treatment of epilepsy.
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Objective To study the effect of rimonabant, cannabinoid receptor 1(CB1) antagonist, on the expressions of CB1 andα-smooth muscle actin (α-SMA) in C57 mice with experimental hepatic fibrosis, and their mechanisms in liver fibrosis progression thereof. Methods Thirty C57 mice were randomly divided into three groups, normal control group, mod-el control group and model+rimonabant group, 10 mice for each group. The mouse model of experimental hepatic fibrosis was induced by intraperitoneal injection with 10%CCl4 for two weeks. The normal saline was delivered by gavage daily in normal control group and model control group. Rimonabant was given to mice in model+rimonabant group. Mice were sacri-ficed at the end of eight weeks. Samples of liver tissue were collected. The expressions of CB1 andα-SMA in liver tissue of mice were observed by immunohistochemical staining. The score of fibrosis stage (S) in liver tissue was also analyzed. Re-sults The positive expressions of CB1 andα-SMA and the score S were significantly higher in model control group and model+rimonabant group than those in normal control group (P<0.05). The positive expressions of CB1 andα-SMA and the score S were significantly lower in rimonabant group than those in model control group (P<0.05). There were positive corre-lations in CB1,α-SMA and S scores between normal control group, model control group and model+rimonabant group (P<0.05). Conclusion The activation of CB1 can promote the formation of liver fibrosis. The anti-fibrotic effect of rimonabant, CB1 antagonist, related with the inhibiting of the proliferation and activation of hepatic stellate cells (HSC), and the inhibit-ing of the expression of CB1.
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BACKGROUND/AIMS: This study was designed to investigate the possibility that the enhanced nociceptive responsiveness associated with canabonoid type 1 receptors (CB1Rs) and identify its role in mediating visceral hypersensitivity induced by chronic restraint stress. METHODS: Rats were exposed to daily partial restraint stress or sham partial restraint stress with intraperitoneal injection of the vehicle, CB1R agonist or antagonist for 4 consecutive days. We tested the visceromotor reflex to colorectal distention at day 0 and 5. Reverse-transcription polymerase chain reaction and Western blot were used to assess the expression of CB1Rs. RESULTS: Intraperitoneal CB1 agonist (ACEA) injection significantly diminished (p < 0.05) the enhanced visceromotor reflex to colorectal distention at day 5 in stressed rats. Change in electromyogram response after ACEA over baseline, at pressure of 40 mmHg (+13.3 +/- 2.2), 60 mmHg (+15.3 +/- 2.8) and 80 mmHg (+17.0 +/- 4.0) were much lower than in the control animals, which were +35.9 +/- 5.1, +41.1 +/- 6.3 and +54.1 +/- 9.6, respectively. Whereas, CB1 antagonist (SR141716A) had an opposite effect. Compared with control group, the change in electromyogram response after SR141716A over baseline was significantly enhanced (p < 0.05) for the distending pressure of 40 mmHg (+56.0 +/- 10.3), 60 mmHg (+74.6 +/- 12.3) and 80 mmHg (+82.9 +/- 11.0), respectively. Reverse-transcription polymerase chain reaction and Western blotting demonstrated the stress-induced up-regulation of colon CB1Rs (p < 0.05). CONCLUSIONS: Our results suggest there is a key contribution of peripheral CB1Rs involved in the maintenance of visceral hyperalgesia after repeated restraint stress, providing a novel mechanism for development of peripheral visceral sensitization.