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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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Objective:To evaluate the role of cannabinoid type 2 receptor (CB2R) in sevoflurane postconditioning-induced reduction of intestinal ischemia-reperfusion (I/R) injury in rats.Methods:Twenty-four clean-grade healthy male Sprague-Dawley rats, aged 8-10 weeks, weighing 220-270 g, were divided into 4 groups ( n=6 each) using a random number table method: sham operation group (group Sham), intestinal I/R group (group I/R), intestinal I/R+ sevoflurane postconditioning group (group Sevo) and intestinal I/R+ sevoflurane postconditioning+ CB2R antagonist AM630 group (group AM). The model of intestinal I/R injury was established by occluding the superior mesenteric artery for 45 min followed by 2 h reperfusion.In the group Sevo, 2% sevoflurane was inhaled immediately at the beginning of reperfusion for 30 min.In the group AM, CB2R antagonist AM630 3 mg/kg was intraperitoneally injected at 1 h before ischemia, and the other treatments were similar to those previously described in group Sevo.At 2 h of reperfusion, the animals were sacrificed after anesthesia, and small intestinal tissues were obtained for microscopic examination of the pathologic changes which was scored according to Chiu and for determination of wet/dry weight ratio (W/D ratio), for detection of malondialdehyde (MDA) content (by thiobarbituric acid colorimetry), for determination of myeloperoxidase (MPO) activity (by MPO assay) and cleaved caspase-3 protein expression (by Western blot). Results:Compared with group Sham, the Chui score, W/D ratio, MDA content and MPO activity in the intestinal tissues were significantly increased, cleaved caspase-3 expression was up-regulated in group I/R ( P<0.05). Compared with group I/R, the Chui score, W/D ratio, MDA content and MPO activity in the intestinal tissues were significantly decreased, cleaved caspase-3 expression was down-regulated in group Sevo ( P<0.05). Compared with group Sevo, the Chui score, W/D ratio, MDA content and MPO activity were significantly increased, cleaved caspase-3 expression was up-regulated in group AM ( P<0.05). Conclusion:CB2R is involved in the process of sevoflurane postconditioning-induced reduction of intestinal I/R injury in rats.
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Objective:To evaluate the relationship between the over-expression of endocannabinoid receptor 2 (CB2R) and macrophage pyroptosis in mice.Methods:Bone marrow-derived macrophages of mice were transfected by lentivirus vector and successfully screened out two stable cell lines: lentivirus LV5 negative control cells (LV5-NC) and lentivirus LV5CB2R overexpressing cells (OE). Two cell lines were respectively divided into 3 groups ( n=18 each) using a random number table method: control group (LV5-NC-C group, OE-C group), LPS/ATP group (LV5-NC-LPS/ATP group, OE-LPS/ATP group) and CB2R specific agonist HU308 group (LV5-NC-HU308 group, OE-HU308 group). Cells in group C were commonly cultured.In LPS/ATP group, cells were incubated with LPS at a final concentration of 0.5 μg/ml for 5 h, and then incubated with ATP at the final concentration of 5 mmol/L for 1 h. In group LPS/ATP+ HU308, cells were incubated for 5 h with LPS at the final concentration of 0.5 μg/ml and HU308 at the final concentration of 10 μmol/L and then with ATP at the final concentration of 5 mmol/L for 1 h. The expression of CB2R, nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3), caspase-1, and gasdermin D (GSDMD) mRNA was detected by real-time polymerase chain reaction, the expression of caspase-1 was detected by Western blot, and the concentrations of interleukin-18 (IL-18) and IL-1β in the culture medium were determined by enzyme-linked immunosorbent assay. Results:In each cell line, compared with group C, the expression of NLRP3, caspase-1 and GSDMD was significantly up-regulated, and the concentrations of IL-18 and IL-1β were increased in group LPS/ATP ( P<0.05). Compared with group LPS/ATP, the expression of NLRP3, caspase-1 and GSDMD was significantly down-regulated, the concentrations of IL-18 and IL-lβ were decreased in group HU308 ( P<0.05). There was no significant differences in the indicators mentioned above between group V5-NC-C and group OE-C, between group LV5-NC-LPS/ATP and group OE-LPS/ATP, and between group LV5-NC-HU308 and OE-HU308 ( P>0.05). Conclusion:Over-expression of CB2R gene cannot effectively inhibit the occurrence of macrophage pyroptosis, and only activation of CB2R can inhibit it in mice.
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Objective To evaluate the effect of activating cannabinoid receptor 2 (CB2R) on sepsis-induced acute lung injury and the role of autophagy in mice.Methods Twenty-four SPF male C57BL/6 mice,aged 8-10 weeks,weighing 20-25 g,were divided into 4 groups (n=6 each) using a random number table method:sham operation group (group Sham),sepsis group (group Sep),sepsis plus CB2R agonist HU308 group (group Sep+HU308) and sepsis plus HU308 plus autophagy inhibitor 3-methyladenine group (group Sep+HU308+3-MA).Sepsis was induced by cecal ligation and puncture in anesthetized mice.HU308 2.5 mg/kg was intraperitoneally injected at 15 min after surgery in Sep+HU308 and Sep+ HU308+3-MA groups,and 15 min later 3-MA 10 mg/kg was intraperitoneally injected in group Sep+ HU308+3-MA.Lung tissues were obtained at 12 h after surgery and stained with haematoxylin and eosin for examination of the pathological changes which were scored and for determination of the expression of tumornecrosis factor-alpha (TNF-α),interleukin-18 (IL-18) and IL-1β mRNA (by real-time polymerase chain reaction),expression of autophagy-related protein 5 (Atg5) (by immuno-histochemistry),and expression of microtubule-associated protein 1 light chain 3 (LC3),Beclin-1 and p62 (by Western blot).The ratio of LC3Ⅱ to LC3Ⅰ (LC3Ⅱ/LC3Ⅰ ratio) was calculated.Results Compared with group Sham,the expression of TNF-α,IL-18 and IL-1β mRNA was significantly up-regulated,and LC3 Ⅱ/LC3 Ⅰ ratio and lung injury score were increased in the other three groups,the expression of Beclin-1 was up-regulated,and the expression of p62 was down-regulated in group Sep and group Sep+HU308,and the expression of p62 was significantly up-regulated in group Sep+HU308+3-MA (P＜0.05).Compared with group Sep,the expression of TNF-α,IL-18 and IL-1β mRNA was significantly down-regulated,the expression of Atg5 was up-regulated,and lung injury score was decreased in group Sep+ HU308 and group Sep+ HU308 + 3-MA,LC3Ⅱ/LC3Ⅰ ratio was increased,the expression of Beclin-1 was up-regulated,and the expression of p62 was down-regulated in group Sep+HU308,and the expression of Beclin-1 was down-regulated,and the expression of p62 was up-regulated in group Sep + HU308 + 3-MA (P ＜ 0.05).Compared with group Sep+ HU308,the expression of TNF-α,IL-18 and IL-1β mRNA was significantly up-regulated,the expression of Atg5 and Beclin-1 was down-regulated,LC3Ⅱ/LC3Ⅰ ratio was decreased,the expression of p62 was up-regulated,and lung injury scores were increased in group Sep+HU308+3-MA (P＜0.05).Conclusion Activating CB2R can alleviate acute lung injury in septic mice,and the mechanism may be partially related to enhancing autophagy and reducing inflammatory responses.
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Objective To investigate the role of hippocampal cannabinoid receptor 2 (CB2R) in postoperative cognitive dysfunction (POCD) in mice.Methods Fifty-four healthy male C57BL/6 mice,aged 12-16 weeks,weighing 20-30 g,were divided into 3 groups (n=18 each) using a random number table:control group (group C),group POCD and POCD plus CB2R agonist JWH133 group (group POCD+J).The mice were subjected to an intramedullary fixation for tibial fracture under 1.5％ isoflurane anesthesia to establish POCD model.In group POCD+J,2 mg/kg JWH133 was injected intraperitoneally at a total volume of 10 ml/kg after emergence from anesthesia and then the injection was repeated once a day until the 7th day after surgery.Open field test was carried out on 1 day before surgery and 1,3 and 7 days after surgery to evaluate the locomotor activity.Fear conditioning test was carried out at 15 min after completion of open field test.Mice were sacrificed at 2 h after the end of behavioral test,and the hippocampus was harvested for determination of the expression of tumor necrosis factor-alpha (TNF-α),interleukin-1beta (IL-1β),monocyte chemotactic protein-1 (MCP-1) and CB2R (by Western blot) and expression of CD11b in hippocampal tissues (by immunofluorescence).Results There was no significant difference in the total exploring distance in open field test,percentage of freezing time in contextual fear conditioning test or percentage of freezing time in tone-fear conditioning text at each time point among the three groups (P＞0.05).Compared with group C,the percentage of freezing time in contextual fear conditioning test was significantly decreased,and the expression of TNF-α,IL-1β,MCP-1,CD11b and CB2R was up-regulated after surgery in group S (P＜0.05).Compared with group S,the percentage of freezing time in contextual fear conditioning test was significantly increased,and the expression of TNF-α,IL-1β,MCP-1,CD11band CB2R was down-regulated after surgery in group S+J (P＜ 0.05).Conclusion Activation of hippocampal CB2R may be involved in the endogenous protective mechanism of POCD in mice,and the mechanism is related to inhibiting activation of hippocampal microglia and attenuating central inflammatory responses.
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Objective To evaluate the role of excitatory amino acid transporter 2 ( EAAT2) in can-nabinoid receptor 2 ( CB2 receptor) activation-induced attenuation of microglial injury caused by glutamate. Methods N9 microglial cells were divided into 4 groups ( n=26 each) using a random number table meth-od: control group ( group Con) , glutamate group ( group Glu) , CB2 receptor agonist AM1241 plus gluta-mate group (group AM1241+Glu) and AM1241 plus EAAT inhibitor TBOA plus glutamate group (group AM1241+TBOA+Glu) . The cells were routinely cultured for 30 h in group Con. In group Glu, the cells were routinely cultured for 6 h, and then were incubated for 24 h in the culture medium containing gluta-mate 10 mmol∕L. In group AM1241+Glu, the cells were incubated for 4 h in the culture medium containing AM12412 μmol∕L, and then were routinely cultured for 2 h, and then were incubated for 24 h in the cul-ture medium containing glutamate 10 mmol∕L. In group AM1241+TBOA+Glu, the cells were incubated for 4 h in the culture medium containing AM12412 μmol∕L and TBOA 100 μmol∕L, and then were routinely cultured for 2 h, and then were incubated for 24 h in the culture medium containing glutamate 10 mmol∕L. The cell viability was measured by MTT assay, the activity of lactic dehydrogenase ( LDH) in supernatant was determined using colorimetric method, and the expression of EAAT2 was determined by Western blot. Results Compared with group Con, the cell viability was significantly decreased and LDH activity was in-creased in Glu, AM1241+Glu and AM1241+TBOA+Glu groups, and the expression of EAAT2 was signifi-cantly up-regulated in Glu and AM1241+Glu groups ( P<0. 05) . Compared with group Glu, the cell viabil-ity was significantly increased, LDH activity was decreased, and the expression of EAAT2 was up-regulated in group AM1241+Glu ( P<0. 05) , and no significant change was found in the parameters mentioned above in group AM1241+TBOA+Glu ( P>0. 05) . Compared with group AM1241+Glu, the cell viability was sig-nificantly decreased, LDH activity was increased, and the expression of EAAT2 was down-regulated in group AM1241+TBOA+Glu ( P<0. 05) . Conclusion The mechanism by which the activation of CB2 re-ceptor attenuates microglial injury caused by glutamate is related to up-regulating the expression of EAAT2.
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ObjectlveTo evaluate the role of cannabinoid receptor 2 (CB2 receptor) in microglial injury induced by glutamate.MethodsMicroglia cells were randomly divided into 4 grups:control group (group C),microglial injury group ( group Ⅰ),specific CB2 receptor agonist AM 1241 group ( group AM1241 ) and specific CB2 receptor antagonist AM630 group (group AM630).In group C,the cells were cultured routinely for 26 h.In group Ⅰ,the cells were incubated in the culture medium containing glutamate 10 mmol/L for 24 h.In group AM1241,the cells were incubated in the culture medium containing AM1241 2 μmol/L for 2 h,and then in the culture medium containing glutamate 10 mmol/L for 24 h.In group AM630,the cells were incubated in the culture medium containing AM630 2 μmol/L for 2 h,and then in the culture medium containing glutamate 10 mmol/L for 24 h.The cell viability and release of LDH were measured.Microglial morphology was observed under microscope.Results Compared with group C,the cell viability was significantly decreased,and the release of LDH was significantly increased in groups Ⅰ,AM1241 and AM630 (P ＜ 0.05).Compared with group Ⅰ,the cell viability was significantly increased,and the release of LDH was significantly decreased in group AM1241 ( P ＜ 0.05).There was no significant difference in the cell viability and the release of LDH between groups 1 and AM630 ( P ＞ 0.05).Conclusion Glutamate induces microglial injury through inhibiting the function of CB2 receptor.
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Objective To study the expression and distribution of CB2 in rat skin tissue. Method Immunohistochemistrial technics were employed to study the expression and distribution of CB2 in rat skin tissue. Results CB 2 receptors mostly presented in suprabasal layers of the epidermis and hair follicles in dermis by CB2 like immunoreactivity with a N terminal anti CB2 receptor antibody. The positive expression of CB2 appeared in rat spleen and a negative result occured in liver. Conclusion The CB2 receptors distributed mainly in the rats, epidermis and hair follicles, may involve in some of the dermic physiological and pathological process, such as the communication between central neural system and skin.