P2X7r antagonist suppressed hepatic stellate cells activation through NLPR3 inflammasome signaling

P2X7 receptor （P2X7r） is important in inflammation and fibrosis. The aim of the present study was to investigate the effect of P2X7r inhibition, using a specific inhibitor （A438079） to prevent the development of liver fibrosis on human hepatic stellate cells, LX-2. The supernatant from lipopolysaccharide （LPS）-stimulated RAW 264.7 mouse macrophages was supplemented to LX-2 cells for 24 h. LX-2 cells were primed with LPS for 4 h and subsequently stimulated for 30 rain with 3 mmol · L^-1 of adenosine 5＇-triphosphate （ATP）. A438079 （ 10 μmol · L^-1） was supplemented to LX-2 cells 10 rain prior to ATP. Directly treated with LPS on LX-2 cells, mRNA ex- pressions of IL-1β, IL-18 and IL-6 were increased, as well as P2X7r. And caspase-1, ASC and NLRP3 mRNA ex- pressions were increased with LPS stimulation. LPS stimulation also increased oL-SMA and collagen I mRNA expres- sions. Interestingly treatment of LX-2 cells with mediums from LPS-primed RAW 264.7 mouse macrophages exhibi- ted greater increase of mRNA expressions of above genes than those in LX-2 directly treated with LPS. Pretreatment of directly or indirectly LPS-stimulated LX-2 cells with A438079 both suppressed IL-1β mRNA expression. In addi- tion treatment of LPS-primed LX-2 cells with 3 mM ATP induced the significant increase of IL-1β, IL-6, caspase- 1, pannexin-1, α-SMA and collagen I mRNA expression, the increasing of oL-SMA protein expression and cleavage of IL-1β. These events were significantly suppressed by pretreatment with P2X7r antagonist A438079. P2XTr blockade also significantly reduced the protein expression of oL-SMA. Our results suggest that the involvement of the P2X7r-NLRP3 inflammasome pathway in the secretion of IL-1β from extracellular ATP/LPS-stimulated human he- patic stellate cells. This study demonstrated that repression of the P2XTr represents a novel potential therapeutic ap- proach to control liver fibrosis.

Effect of electroacupuncture on inflammatory signal expression in local tissues of rats with chronic pelvic pain syndrome based on purinergic 2X7 receptor/NOD-like receptor pyrin domaincontaining 3 signal pathway

OBJECTIVES: To study the expression of inflammatory signal in local prostate tissue of chronic pelvic pain syndrome(CPPS) rats by electroacupuncture(EA) of Guanyuan(CV4), Zhongji(CV3), Huiyang(BL35) and Sanyinjiao(SP6), and to explore the possible mechanism of anti-inflammatory and analgesic effects of EA. METHODS : A total of 36 Sprague-Dawley male rats were randomly divided into three groups: control, model and EA(n=12 rats/group). The CPPS model was made by injection of CFA into ventral lobes of the prostate(0.1 m L). Electric acupuncture apparatus was applied to stimulate Guanyuan(CV4), Zhongji(CV3), bilateral Huiyang(BL35) and Sanyinjiao(SP6) acupoints in EA group. The general condition of rats was observed and the prostate index(PI) was calculated. The thermal pain threshold was collected after each therapeutic course. Histopathological changes of the prostate tissue were examined by hematoxylin-eosin staining method. The expression levels of tumor necrosis factor α(TNF-α), interleukin-1β(IL-1β) and prostaglandin E2(PGE2) in prostatic homogenates were measured by enzyme linked immunosorbent assay(ELISA). Moreover, the expression levels of purinergic 2X7 receptor(P2X7R), NOD-like receptor pyrin domain-containing 3(NLRP3), caspase-1 and interleukin-18(IL-18) m RNA were quantified by quantitative real-time polymerase chain reaction. RESULTS: Compared with control group, the PI of rats increased, and the thermal pain threshold decreased significantly in model group. The morphological structure of prostate tissues of rats in model group was severely damaged with a large number of inflammatory cells infiltration. Additionally, the levels of TNF-α, IL-1β and PGE2 were higher, and the expressions of P2X7R, NLRP3, caspase-1 and IL-18 m RNA were higher than those in control group. After EA treatment, the PI was significantly decreased, the thermal pain threshold was significantly increased, and the tissue damage was significantly improved. The expressions of inflammatory cytokines were lower in EA group, and expression of P2X7R/NLRP3 pathway was down-regulated. CONCLUSION: The effect of EA at Guanyuan(CV4), Zhongji(CV3), Huiyang(BL35) and Sanyinjiao(SP6) can improve inflammation and pain symptoms of CPPS rats induced by Complete Freund’s adjuvant(CFA). This suggests that EA at Guanyuan(CV4), Zhongji(CV3), Huiyang(BL35) and Sanyinjiao(SP6) can produce antiinflammatory analgesia effect by preventing the activation of P2X7R/NLRP3 signal pathway, inhibit the release of inflammatory cytokines in CPPS rats, which may provide a putative novel target for the treatment of CPPS.

Sleep Deprivation Selectively Down-Regulates Astrocytic 5-HT2B Receptors and Triggers Depressive-Like Behaviors via Stimulating P2X7 Receptors in Mice

Chronic loss of sleep damages health and disturbs the quality of life.Long-lasting sleep deprivation(SD)as well as sleep abnormalities are substantial risk factors for major depressive disorder,although the underlying mechanisms are not clear.Here,we showed that chronic SD in mice promotes a gradual elevation of extracellular ATP,which activates astroglial P2X7 receptors(P2X7Rs).Activated P2X7Rs,in turn,selectively down-regulated the expression of 5-HT2B receptors(5-HT2BRs)in astrocytes.Stimulation of P2X7Rs induced by SD selectively suppressed the phosphorylation of AKT and FoxO3 a in astrocytes,but not in neurons.The overexpression of FoxO3a in astrocytes inhibited the expression of 5-HT2BRs.Down-regulation of 5-HT2BsRs instigated by SD suppressed the activation of STAT3 and relieved the inhibition of Ca2+-dependent phospholipase A2.This latter cascade promoted the release of arachidonic acid and prostaglandin E2.The depression-like behaviors induced by SD were alleviated in P2X7R-KO mice.Our study reveals the mechanism underlying chronic SD-induced depression-like behaviors and suggests 5-HT2BRs as a key target for exploring therapeutic strategies aimed at the depression evoked by sleep disorders.

P2X7 Receptor in Alcoholic Steatohepatitis and Alcoholic Liver Fibrosis

Alcoholic liver disease is one of the most common chronic liver diseases in the world.It is a liver disease caused by prolonged heavy drinking and its main clinical features are nausea,vomiting,enlargement of the liver,and jaundice.Recent studies suggest that Kupffer cell-mediated inflam-matory response is a core driver in the development of alco-holic steatohepatitis and alcoholic liver fibrosis.As a danger signal,extracellular ATP activates the assembly of NLPR3 inflammasome by acting on purine P2X7 receptor,the ac-tivated NLRP3 inflammasome prompts ASC to cleave pro-cCaspase-1 into active caspase-1in KCs.Active caspase-1 promotes the conversion of pro-IL-1βto IL-1β,which fur-ther enhances the inflammatory response.Here,we briefly review the role of the P2X7R-NLRP3 inflammasome axis in the pathogenesis of alcoholic liver disease and the evolution of alcoholic steatohepatitis and alcoholic liver fibrosis.Reg-ulation of the inflammasome axis of P2X7R-NLRP3 may be a new approach for the treatment of alcoholic liver disease.

Effects of moxibustion on the P2X7R/STAT3/VEGF pathway in rats with colitis-associated colon cancer

Objective:To observe the effects of herb-partitioned moxibustion and ginger-partitioned moxibustion on the growth of colon tumors in rats with colitis-associated colon cancer(CACC),and explore the mechanism of moxibustion intervening CACC through the purinergic receptor P2X ligand-gated ion channel 7(P2X7R)/signal transducer and activator of transcription 3(STAT3)/vascular endothelial growth factor(VEGF)pathway.Methods:A total of 26 male Sprague-Dawley rats were selected.According to the random number table method,6 rats were selected as the normal group.The remaining 20 rats were injected intraperitoneally with azoxymethane(AOM)combined with oral dextran sodium sulfate(DSS)to prepare the CACC model.After the model was successfully established,2 rats were randomly selected for model identification.The remaining 18 rats which were successfully modeled were randomly divided into a model group,a herb-partitioned moxibustion group and a ginger-partitioned moxibustion group,with 6 rats in each group.Moxibustion intervention was performed in the herb-partitioned moxibustion group and the ginger-partitioned moxibustion group at Qihai(CV 6)and bilateral Tianshu(ST 25).Moxibustion was performed twice at each point each time,once a day,at a 1-day interval after 6 consecutive interventions,for a total of 30 interventions.After intervention,the colon tumor load,pathological change and histopathological score were observed.Immunohistochemistry was used to detect the expressions of VEGF,P2X7R,phospho-STAT3(p-STAT3),and nuclear factor-kappa B p65(NF-κB p65)proteins in rat colon tissue.Western blot was used to detect the levels of p-STAT3 and NF-κB p65 proteins in rat colon tissue.Results:Compared with the normal group,the colon tumor load and histopathological score in the model group were significantly increased(both P<0.001),and different grades of dysplasia were observed in colon tissue from the model group,reaching the degree of adenocarcinoma;the expression level of P2X7R protein in colon tissue was significantly decreased(P<0.001),and the expression levels of p-STAT3,NF-κB p65 and VEGF proteins were significantly increased(all P<0.001)in the model group.Compared with the model group,the colon tumor load,colon histopathological score and the levels of p-STAT3,NF-κB p65 and VEGF proteins in colon tissue were significantly decreased(all P<0.05)in the herb-partitioned moxibustion group and the ginger-partitioned moxibustion group while the expression levels of P2X7R protein in colon tissue were significantly increased(both P<0.05).Conclusion:Both herb-partitioned moxibustion and ginger-partitioned moxibustion can reduce the colon tumor load in CACC rats and delay the progression of colon adenomas.The mechanism may be mediated by the P2X7R/STAT3 pathway to inhibit STAT3 phosphorylation,thereby reducing VEGF protein expression.

非诺贝特对糖尿病视网膜病变小鼠视网膜神经细胞的保护作用及机制

目的探讨嘌呤受体P2X7-NOD样受体蛋白-3(Nod-like receptor pyrin domain 3,NLRP3)炎性相关信号转导通路在糖尿病小鼠视网膜神经细胞中的表达情况,初步研究非诺贝特对糖尿病视网膜病变(diabetic retinopathy,DR)的保护作用。方法健康雄性小鼠60只,随机分为实验对照组(N组)、糖尿病组(D组)、非诺贝特治疗组(F组),D组及F组通过腹腔内注射链脲佐菌素制备DR模型,分别于造模后每天记录血糖情况,并于4周、8周、12周进行三组间血糖水平的比较。自造模成功后第2天起,F组每天口服非诺贝特100 mg·kg^-1连续喂养12周,4周后免疫荧光化学法观察视网膜神经胶质细胞及视网膜神经节细胞(retinal ganglion cell,RGC)的活化情况,Western blot检测视网膜组织中P2X7、NLRP3蛋白的表达情况。结果与N组相比,D组血糖水平在造模后4周、8周、12周随时间推移均有不同程度增长,差异均有统计学意义(均为P<0.05)。N组中,GFAP少量表达;D组4周时GFAP的表达主要分布于内界膜(inner limiting membrane,ILM)、RGC层和内丛状层(inner plexiform layer,IPL);非诺贝特治疗后,F组小鼠视网膜GFAP主要分布于ILM和RGC层,且密度与D组相比明显减弱。Western blot检测结果显示:N组中,视网膜P2X7和NLRP3蛋白仅有少量表达;D组中二者的表达水平在4周时明显升高,与N组相比,差异均有统计学意义(均为P<0.05);而此时F组经非诺贝特治疗后小鼠视网膜组织中P2X7和NLRP3蛋白的表达水平较D组明显降低,但仍高于N组,差异均有统计学意义(均为P<0.05)。结论非诺贝特可通过下调糖尿病小鼠视网膜组织中P2X7和NLRP3蛋白的表达从而发挥视网膜保护作用。