Background:The nucleotide-binding and oligomerization domain-like receptor protein 3 (NLRP3) inflammasome composed of NLRP3,apoptosis-associated speck-like protein containing CARD (ASC),and caspase-1 is engaged in the...Background:The nucleotide-binding and oligomerization domain-like receptor protein 3 (NLRP3) inflammasome composed of NLRP3,apoptosis-associated speck-like protein containing CARD (ASC),and caspase-1 is engaged in the inflammatory response of many kidney diseases and can be activated by purinergic 2X7 receptor (P2X7R).This study was conducted to explore whether P2X7R plays a pathogenic role in the podocyte damage of obesity-related glomerulopathy (ORG) and whether this role is mediated by the activation ofNLRP3 inflammasome.Methods:A mouse model of ORG was established by high-fat diet feeding.The conditionally immortalized mouse podocytes were cultured with leptin or with leptin and P2X7R antagonist (KN-62 or A438079).The mRNA and protein expression of the P2X7R and NLRP3 inflammasome components including NLRP3,ASC,and caspase-1,as well as the podocyte-associated molecules including nephrin,podocin,and desmin in mouse renal cortex or cultured mouse podocytes were tested by real-time-polymerase chain reaction and Westem blot analysis,respectively.Results:The significantly upregulated expression of P2X7R and NLRP3 inflammasome components and the NLRP3 inflammasome activation were observed in the renal cortex (in fact their location in podocytes was proved by confocal microscopy) of ORG mice in vivo,which were accompanied with the morphological changes of podocyte damage and the expression changes of podocyte-associated molecules.Similar changes in the expression of P2X7R and NLRP3 inflammasome components as well as in the expression ofpodocyte-associated molecules were also observed in the cultured podocyte studies treated by leptin in vitro,and all of the above changes were significantly attenuated by the P2X7R antagonist KN-62 or A438079.Conclusions:P2X7R could trigger the activation ofNLRP3 inflammasome,and the activated P2X7R/NLRP3 inflammasome in podocytes might be involved in the podocyte damage of ORG.展开更多
The brain lymphatic system plays a crucial role in maintaining homeostasis,clearing metabolic waste,and regulating neuroinflammation.Its dysfunction is strongly linked to neurodegenerative diseases such as Alzheimer&#...The brain lymphatic system plays a crucial role in maintaining homeostasis,clearing metabolic waste,and regulating neuroinflammation.Its dysfunction is strongly linked to neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease.In this study,we employed dual-contrast functionalphotoacoustic microscopy to evaluate the impact of lipopolysaccharide-induced central nervous system inflammation on brain lymphatic function and to explore the protective effects of the P2X7 receptor(P2X7R)antagonist.Our findings demonstrated that lipopolysac-charide intervention led to impaired function of the meningeal lymphatic vessels,which was par-tially restored by the P2X7R antagonist,whereas its effects on the glymphatic system and cerebral vessels were minimal.This study further supports the feasibility of photoacoustic microscopy for assessing brain lymphatic function and highlights the therapeutic potential of P2X7R antagonism.These findings suggest that P2X7R may serve as a key target for modulating brain-lymphatic interactions,providing an experimental foundation for developing intervention strategies for neuroinflammatory and neurodegenerative diseases.展开更多
OBJECTIVE:to investigate the anti-arthritic effects of lappaconitine(LA)on adjuvant-induced arthritis in Sprague-Dawley rats and its possible involvement in the regulation of M1/M2 macrophage balance through the P2X7 ...OBJECTIVE:to investigate the anti-arthritic effects of lappaconitine(LA)on adjuvant-induced arthritis in Sprague-Dawley rats and its possible involvement in the regulation of M1/M2 macrophage balance through the P2X7 receptor(P2X7r).METHODS:Rats were immunized with complete Freund's adjuvant and then intraperitoneally administered LA(2,4,or 8 mg·kg^(-1)·d^(-1))or methotrexate(0.5 mg/kg per 3 d)for 14 d.The anti-arthritic effects of LA were evaluated through arthritis index(AI)assessment,ankle diameter measurement,and histopathological staining analysis.The analgesic effect of LA on arthritis was measured using mechanical withdrawal threshold testing and gait scoring.The impacts of LA on macrophage polarization,the expression of pro-/anti-inflammatory cytokines and P2X7r were analyzed using quantitative real-time polymerase chain reaction,enzyme-linked immunosorbent assay,and Western blotting.RESULTS:LA treatment significantly reduced AI scores,paw swelling,joint destruction,and inflammatory cell infiltration,and alleviated arthritis pain.Additionally,LA promoted a balanced M1/M2 ratio by increasing the m RNA expression level of M2 marker arginase 1 and decreasing those of M1 markers inducible nitric oxide synthase and interleukin(IL)-1βin synovial tissues.Furthermore,LA lowered the levels of three M1-related cytokines,namely tumor necrosis factor-α,IL-1βand IL-18,and raised the level of the M2-related cytokine IL-10.Further research showed that treatment with LA inhibited the expression of P2X7r.CONCLUSION:Our findings indicate that the notable therapeutic and analgesic effects of LA on AIA rats are exerted through balancing the M1/M2 ratio,probably via P2X7r.展开更多
OBJECTIVE To investigate the effect of P2X7receptor(P2X7r)inhibition,using a specific inhibitor(A438079)to prevent the development of liver fibrosis on human hepatic stellate cells,LX-2.METHODS The supernatant from li...OBJECTIVE To investigate the effect of P2X7receptor(P2X7r)inhibition,using a specific inhibitor(A438079)to prevent the development of liver fibrosis on human hepatic stellate cells,LX-2.METHODS The supernatant from lipopolysaccharide(LPS)-stimulated RAW264.7 mouse macrophages was supplemented to LX-2 cells for 24 h.LX-2cells were primed with LPS for 4h and subsequently stimulated for 30 min with 3mmol·L-1 of adenosine 5′-triphosphate(ATP).A438079(10μmol·L-1)was supplemented to LX-2 cells 10 min prior to ATP.RESULTS Directly treated with LPS on LX-2 cells,mRNA expressions of IL-1β,IL-18 and IL-6 were increased,as well as P2X7 r.And caspase-1,ASC and NLRP3 mRNA expressions were increased with LPS stimulation.LPS stimulation also increasedα-SMA and collagenⅠ mRNA expressions.Interestingly treatment of LX-2cells with mediums from LPS-primed RAW264.7mouse macrophages exhibited greater increase of mRNA expressions of above genes than those in LX-2directly treated with LPS.Pretreatment of directly or indirectly LPS-stimulated LX-2 cells with A438079 both suppressed IL-1βmRNA expression.In addition treatment of LPS-primed LX-2 cells with 3mmol·L-1 ATP induced the significant increase of IL-1β,IL-6,caspase-1,pannexin-1,α-SMA and collagenⅠ mRNA expression,the increasing ofα-SMA protein expression and cleavage of IL-1β.These events were significantly suppressed by pretreatment with P2X7 rantagonist A438079.P2X7 rblockade also significantly reduced the protein expression ofα-SMA.CONCLUSION Our results suggest that the involvement of the P2X7r-NLRP3 inflammasome pathway in the secretion of IL-1βfrom extracellular ATP/LPS-stimulated human hepatic stellate cells.This study demonstrated that repression of the P2X7 rrepresents a novel potential therapeutic approach to control liver fibrosis.展开更多
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...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.展开更多
Interleukin-1α and interleukin-1β aggravate neuronal injury by mediating the inf1αmmatory reaction following ischemic/hypoxic brain injury. It remains unclear whether interleukin-1α and interleukin-1β are release...Interleukin-1α and interleukin-1β aggravate neuronal injury by mediating the inf1αmmatory reaction following ischemic/hypoxic brain injury. It remains unclear whether interleukin-1α and interleukin-1β are released by microglia or astrocytes. This study prepared hippocampal slices that were subsequently subjected to oxygen and glucose deprivation. Hematoxylin-eosin staining verified that neurons exhibited hypoxic changes. Results of enzyme-linked immunosorbent assay found that interleukin-1α and interleukin-1β participated in this hypoxic process. Moreover, when hypoxic injury occurred in the hippocampus, the release of interleukin-1α and interleukin-1β was mediated by the P2X4 receptor and P2X7 receptor. Immunofluorescence staining revealed that during ischemia/hypoxia, the P2X4 receptor, P2X7 receptor, interleukin-1α and interleukin-1β expression was detectable in rat hippocampal microglia, but only P2X4 receptor and P2X7 receptor expression was detected in astrocytes. Results suggested that the P2X4 receptor and P2X7 receptor, respectively, mediated interleukin-1α and interleukin-1β released by microglia, resulting in hippocampal ischemic/hypoxic injury. Astrocytes were activated, but did not synthesize or release interleukin-1α and interleukin-1β.展开更多
Cerebral ischemia is one of the most common diseases resulting in death and disability in aged people. It leads immediately to rapid energy failure, ATP depletion, and ionic imbalance, which increase extracellular ATP...Cerebral ischemia is one of the most common diseases resulting in death and disability in aged people. It leads immediately to rapid energy failure, ATP depletion, and ionic imbalance, which increase extracellular ATP levels and accordingly activate P2X7 receptors. These receptors are ATP-gated cation channels and widely distributed in nerve cells, especially in the immunocompetent cells of the brain. Currently, interest in the roles of P2Xz receptors in ischemic brain injury is growing. In this review, we discuss recent research progress on the actions of P2X7 receptors, their possible mechanisms in cerebral ischemia, and the potential therapeutic value of P2X7 receptor antagonists which may provide a new target both for clinical and for research purposes.展开更多
The present study aimed to explore the mechanism underlying the protective effects of hydrogen sulfide against neuronal damage caused by cerebral ischemia/reperfusion. We established the middle cerebral artery occlusi...The present study aimed to explore the mechanism underlying the protective effects of hydrogen sulfide against neuronal damage caused by cerebral ischemia/reperfusion. We established the middle cerebral artery occlusion model in rats via the suture method. Ten minutes after middle cerebral artery occlusion, the animals were intraperitoneally injected with hydrogen sulfide donor compound sodium hydrosulfide. Immunofluorescence revealed that the immunoreactivity of P2X7 in the cerebral cortex and hippocampal CA1 region in rats with cerebral ischemia/reperfusion injury decreased with hydrogen sulfide treatment. Furthermore, treatment of these rats with hydrogen sulfide significantly lowered mortality, the Longa neurological deficit scores, and infarct volume. These results indicate that hydrogen sulfide may be protective in rats with local cerebral ischemia/reperfusion injury by down-regulating the expression of P2X7 receptors.展开更多
Acute kidney injury(AKI)is a common clinical serious illness.Esculin(ES)is a coumarin compound of traditional Chinese medicine Cortex Fraxini.Our previous study has found that ES protects against inflammation and rena...Acute kidney injury(AKI)is a common clinical serious illness.Esculin(ES)is a coumarin compound of traditional Chinese medicine Cortex Fraxini.Our previous study has found that ES protects against inflammation and renal damage in diabetic rats.In the present study,we aimed to investigate the effects and the possible mechanism of ES against lipopolysaccharides(LPS)-induced AKI in mice.Renal morphology was observed by H&E staining.Renal function was evaluated by blood urea nitrogen(BUN)level and creatinine content in serum.Inflammatory factor levels were measured by ELISA assay.The inflammatory proteins were analyzed by RT-PCR and Western blotting analysis.The results showed that ES alleviated LPS-induced pathological injury and renal dysfunction,and decreased BUN level and creatinine content in serum.In addition,ES significantly reduced the release of pro-inflammatory factors,including IL-1β,IL-6 and TNF-α,chemokine MCP-1 and cell adhesion molecule ICAM-1.Furthermore,the expressions of inflammatory pathway proteins P2 X7,HMGB1,TLR4 and MyD88 both at the mRNA and protein levels were all down-regulated by ES in the kidney tissue of LPS-challenged mice.These results suggested ES protected against LPS-induced AKI through inhibiting P2 X7 expression and HMGB1/TLR4 inflammatory pathway.展开更多
The intestinal mucosa is a highly compartmentalized structure that forms a directbarrier between the host intestine and the environment, and its dysfunction couldresult in a serious disease. As T cells, which are impo...The intestinal mucosa is a highly compartmentalized structure that forms a directbarrier between the host intestine and the environment, and its dysfunction couldresult in a serious disease. As T cells, which are important components of themucosal immune system, interact with gut microbiota and maintain intestinalhomeostasis, they may be involved in the process of intestinal barrier dysfunction.P2X7 receptor (P2X7R), a member of the P2X receptors family, mediates the effectsof extracellular adenosine triphosphate and is expressed by most innate or adaptiveimmune cells, including T cells. Current evidence has demonstrated thatP2X7R is involved in inflammation and mediates the survival and differentiationof T lymphocytes, indicating its potential role in the regulation of T cell function.In this review, we summarize the available research about the regulatory role andmechanism of P2X7R on the intestinal mucosa-derived T cells in the setting ofintestinal barrier dysfunction.展开更多
The present study was designed to investigate the mechanisms by which P2X7 receptors(P2X7Rs)mediate the activation of vasopressinergic neurons thereby increasing sympathetic hyperactivity in the paraventricular nucleu...The present study was designed to investigate the mechanisms by which P2X7 receptors(P2X7Rs)mediate the activation of vasopressinergic neurons thereby increasing sympathetic hyperactivity in the paraventricular nucleus(PVN) of the hypothalamus of rats with acute myocardial ischemia(AMI). The left anterior descending branch of the coronary artery was ligated to induce AMI in rats. The rats were pretreated with BBG(brilliant blue G, a P2X7R antagonist), nelivaptan(a vasopressin V1b receptor antagonist), or diphenyleneiodonium(DPI) [an nicotinamide adenine dinucleotide phosphate(NADPH)oxidase inhibitor]. Hemodynamic parameters of the heart were monitored. Myocardial injury and cardiomyocyte apoptosis were assessed. In the PVN of AMI rats, P2X7R mediated microglial activation, while reactive oxygen species(ROS) and NADPH oxidase 2(NOX2) were higher than in the sham group. Intraperitoneal injection of BBG effectively reduced ROS production and vasopressin expression in the PVN of AMI rats. Moreover, both BBG and DPI pretreatment effectively reduced sympathetic hyperactivity and ameliorated AMI injury, as represented by reduced inflammation and apoptosis of cardiomyocytes.Furthermore, microinjection of nelivaptan into the PVN improved cardiac function and reduced the norepinephrine(AE) levels in AMI rats. Collectively, the results suggest that, within the PVN of AMI rats, P2X7R upregulation mediates microglial activation and the overproduction of ROS, which in turn activates vasopressinergic neuron V1b receptors and sympathetic hyperactivity, hence aggravating myocardial injury in the AMI setting.展开更多
Painful diabetic neuropathy(PDN)is a diabetes mellitus complication.Unfortunately,the mechanisms underlying PDN are still poorly understood.Adenosine triphosphate(ATP)-gated P2X7 receptor(P2X7R)plays a pivotal role in...Painful diabetic neuropathy(PDN)is a diabetes mellitus complication.Unfortunately,the mechanisms underlying PDN are still poorly understood.Adenosine triphosphate(ATP)-gated P2X7 receptor(P2X7R)plays a pivotal role in non-diabetic neuropathic pain,but little is known about its effects on streptozotocin(STZ)-induced peripheral neuropathy.Here,we explored whether spinal cord P2X7R was correlated with the generation of mechanical allodynia(MA)in STZ-induced type 1 diabetic neuropathy in mice.MA was assessed by measuring paw withdrawal thresholds and western blotting.Immunohistochemistry was applied to analyze the protein expression levels and localization of P2X7R.STZ-induced mice expressed increased P2X7R in the dorsal horn of the lumbar spinal cord during MA.Mice injected intrathecally with a selective antagonist of P2X7R and P2X7R knockout(KO)mice both presented attenuated progression of MA.Double-immunofluorescent labeling demonstrated that P2X7R-positive cells were mostly co-expressed with Iba1(a microglia marker).Our results suggest that P2X7R plays an important role in the development of MA and could be used as a cellular target for treating PDN.展开更多
We hypothesized that the P2X7 receptor may be the target of isoflurane, so we investigated the roles of the P2X7 receptor and inositol triphosphate receptor in calcium overload and neuronal apoptosis induced by isoflu...We hypothesized that the P2X7 receptor may be the target of isoflurane, so we investigated the roles of the P2X7 receptor and inositol triphosphate receptor in calcium overload and neuronal apoptosis induced by isoflurane in cultured embryonic rat hippocampal neurons. Results showed that isoflurane induced widespread neuronal apoptosis and significantly increased cytoplasmic Ca^2＋ Blockade of P2X7 receptors or removal of extracellular Ca^2＋ combined with blockade of inositol triphosphate receptors completely inhibited apoptosis or increase in cytoplasmic Ca^2＋. Removal of extracellular Ca^2＋ or blockade of inositol triphosphate receptor alone could partly inhibit these effects of isoflurane. Isoflurane could directly activate P2X7-gated channels and induce inward currents, but did not affect the expression of P2X7 receptor protein in neurons. These findings indicate that the mechanism by which isoflurane induced neuronal apoptosis in rat developing brain was mediated by intracellular calcium overload, which was caused by P2X7 receptor mediated calcium influx and inositol triphosphate receptor mediated calcium release.展开更多
The enteric nervous system(ENS)consists of thousands of small ganglia arranged in the submucosal and myenteric plexuses,which can be negatively affected by Crohn’s disease and ulcerative colitis-inflammatory bowel di...The enteric nervous system(ENS)consists of thousands of small ganglia arranged in the submucosal and myenteric plexuses,which can be negatively affected by Crohn’s disease and ulcerative colitis-inflammatory bowel diseases(IBDs).IBDs are complex and multifactorial disorders characterized by chronic and recurrent inflammation of the intestine,and the symptoms of IBDs may include abdominal pain,diarrhea,rectal bleeding,and weight loss.The P2X7 receptor has become a promising therapeutic target for IBDs,especially owing to its wide expression and,in the case of other purinergic receptors,in both human and model animal enteric cells.However,little is known about the actual involvement between the activation of the P2X7 receptor and the cascade of subsequent events and how all these activities associated with chemical signals interfere with the functionality of the affected or treated intestine.In this review,an integrated view is provided,correlating the structural organization of the ENS and the effects of IBDs,focusing on cellular constituents and how therapeutic approaches through the P2X7 receptor can assist in both protection from damage and tissue preservation.展开更多
Previous studies have confirmed that oxidized adenosine triphosphate, a P2X7 receptor antagonist, attenuates lipopolysaccharide-mediated microglial activation and inflammatory expression following neuronal damage in r...Previous studies have confirmed that oxidized adenosine triphosphate, a P2X7 receptor antagonist, attenuates lipopolysaccharide-mediated microglial activation and inflammatory expression following neuronal damage in rat brain. NaCI and temperature may affect the potency of oxidized adenosine triphosphate. Brilliant blue G is a derivative of a widely used food additive and has little toxicity. This study explored the effects of brilliant blue G, a selective P2X7 receptor antagonist, on microglial activation and inflammation. Results demonstrated that brilliant blue G inhibited the release of cydooxygenase-2 and interleukin-6 in BV2 cells. Immunofluorescence displayed that brilliant blue G could suppress lipopolysaccharide-induced microglial activation. This study used RNA interference to block P2X7 receptor expression and found that small interfering RNA also suppressed the release of cyclooxygenase-2 and interleukin-6 in BV2 cells. These results suggested that downregulation of the P2X7 receptor by brilliant blue G was involved in the inhibition of microglial activation and inflammation.展开更多
Acknowledgments： I would like to express my appreciation to Professor Puro DG for leading me to this research topic during my stay as a research fellow in his laboratory at the University of Michigan in 2001, and als...Acknowledgments： I would like to express my appreciation to Professor Puro DG for leading me to this research topic during my stay as a research fellow in his laboratory at the University of Michigan in 2001, and also to Professor Ikeda T forgiving me the opportunity to study abroad and then to continue to investigate this topic in the Department of Ophthalmology at Osaka Medical College, lapan.展开更多
BACKGROUND The P2X7 receptor is expressed by enteric neurons and enteric glial cells.Studies have demonstrated that administration of a P2X7 receptor antagonist,brilliant blue G(BBG),prevents neuronal loss.AIM To repo...BACKGROUND The P2X7 receptor is expressed by enteric neurons and enteric glial cells.Studies have demonstrated that administration of a P2X7 receptor antagonist,brilliant blue G(BBG),prevents neuronal loss.AIM To report the effects of BBG in ileum enteric neurons immunoreactive(ir)following experimental ulcerative colitis in Rattus norvegicus albinus.METHODS 2,4,6-trinitrobenzene sulfonic acid(TNBS group,n=5)was injected into the distal colon.BBG(50 mg/kg,BBG group,n=5)or vehicle(sham group,n=5)was given subcutaneously 1 h after TNBS.The animals were euthanized after 24 h,and the ileum was removed.Immunohistochemistry was performed on the myenteric plexus to evaluate immunoreactivity for P2X7 receptor,neuronal nitric oxide synthase(nNOS),choline acetyltransferase(ChAT),HuC/D and glial fibrillary acidic protein.RESULTS The numbers of nNOS-,ChAT-,HuC/D-ir neurons and glial fibrillary acidic protein-ir glial cells were decreased in the TNBS group and recovered in the BBG group.The neuronal profile area(μm^2)demonstrated that nNOS-ir neurons decreased in the TNBS group and recovered in the BBG group.There were no differences in the profile areas of ChAT-and HuC/D-ir neurons.CONCLUSION Our data conclude that ileum myenteric neurons and glial cells were affected by ulcerative colitis and that treatment with BBG had a neuroprotective effect.Thus,these results demonstrate that the P2X7 receptor may be an important target in therapeutic strategies.展开更多
A family of novel squaramides/sulfamides based on 1,2-alkamine was developed as chiral bifunctional catalysts to promote the asymmetric alcoholysis of meso cyclic anhydrides. The hemiesters were obtained in high yield...A family of novel squaramides/sulfamides based on 1,2-alkamine was developed as chiral bifunctional catalysts to promote the asymmetric alcoholysis of meso cyclic anhydrides. The hemiesters were obtained in high yield with up to 93% ee. The usefulness of this methodology was demonstrated in the asymmetric synthesis of the key intermediate of P2X7 receptor antagonists.展开更多
BACKGROUND The literature indicates that the enteric nervous system is affected in inflammatory bowel diseases(IBDs)and that the P2X7 receptor triggers neuronal death.However,the mechanism by which enteric neurons are...BACKGROUND The literature indicates that the enteric nervous system is affected in inflammatory bowel diseases(IBDs)and that the P2X7 receptor triggers neuronal death.However,the mechanism by which enteric neurons are lost in IBDs is unknown.AIM To study the role of the caspase-3 and nuclear factor kappa B(NF-κB)pathways in myenteric neurons in a P2X7 receptor knockout(KO)mouse model of IBDs.METHODS Forty male wild-type(WT)C57BL/6 and P2X7 receptor KO mice were euthanized 24 h or 4 d after colitis induction by 2,4,6-trinitrobenzene sulfonic acid(colitis group).Mice in the sham groups were injected with vehicle.The mice were divided into eight groups(n=5):The WT sham 24 h and 4 d groups,the WT colitis 24 h and 4 d groups,the KO sham 24 h and 4 d groups,and the KO colitis 24 h and 4 d groups.The disease activity index(DAI)was analyzed,the distal colon was collected for immunohistochemistry analyses,and immunofluorescence was performed to identify neurons immunoreactive(ir)for calretinin,P2X7 receptor,cleaved caspase-3,total caspase-3,phospho-NF-κB,and total NF-κB.We analyzed the number of calretinin-ir and P2X7 receptor-ir neurons per ganglion,the neuronal profile area(μm^(2)),and corrected total cell fluorescence(CTCF).RESULTS Cells double labeled for calretinin and P2X7 receptor,cleaved caspase-3,total caspase-3,phospho-NF-κB,or total NF-κB were observed in the WT colitis 24 h and 4 d groups.The number of calretinin-ir neurons per ganglion was decreased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(2.10±0.13 vs 3.33±0.17,P<0.001;2.92±0.12 vs 3.70±0.11,P<0.05),but was not significantly different between the KO groups.The calretinin-ir neuronal profile area was increased in the WT colitis 24 h group compared to the WT sham 24 h group(312.60±7.85 vs 278.41±6.65,P<0.05),and the nuclear profile area was decreased in the WT colitis 4 d group compared to the WT sham 4 d group(104.63±2.49 vs 117.41±1.14,P<0.01).The number of P2X7 receptor-ir neurons per ganglion was decreased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(19.49±0.35 vs 22.21±0.18,P<0.001;20.35±0.14 vs 22.75±0.51,P<0.001),and no P2X7 receptor-ir neurons were observed in the KO groups.Myenteric neurons showed ultrastructural changes in the WT colitis 24 h and 4 d groups and in the KO colitis 24 h group.The cleaved caspase-3 CTCF was increased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(485949±14140 vs 371371±16426,P<0.001;480381±11336 vs 378365±4053,P<0.001),but was not significantly different between the KO groups.The total caspase-3 CTCF,phospho-NF-κB CTCF,and total NF-κB CTCF were not significantly different among the groups.The DAI was recovered in the KO groups.Furthermore,we demonstrated that the absence of the P2X7 receptor attenuated inflammatory infiltration,tissue damage,collagen deposition,and the decrease in the number of goblet cells in the distal colon.CONCLUSION Ulcerative colitis affects myenteric neurons in WT mice but has a weaker effect in P2X7 receptor KO mice,and neuronal death may be associated with P2X7 receptor-mediated caspase-3 activation.The P2X7 receptor can be a therapeutic target for IBDs.展开更多
Clostridioides difficile(C.difficile)is the most common pathogen causing health care-associated infections.C.difficile TcdA and TcdB have been shown to activate enteric neurons;however,what population of these cells i...Clostridioides difficile(C.difficile)is the most common pathogen causing health care-associated infections.C.difficile TcdA and TcdB have been shown to activate enteric neurons;however,what population of these cells is more profoundly influenced and the mechanism underlying these effects remain unknown.AIM To characterize a specific population of TcdA-affected myenteric neurons and investigate the role of the P2X7 receptor in TcdA-induced ileal inflammation,cell death,and the changes in the enteric nervous system in mice.METHODS Swiss mice were used to model TcdA-induced ileitis in ileal loops exposed to TcdA(50μg/Loop)for 4 h.To investigate the role of the P2X7 receptor,Brilliant Blue G(50 mg/kg,i.p.),which is a nonspecific P2X7 receptor antagonist,or A438079(0.7μg/mouse,i.p.),which is a competitive P2X7 receptor antagonist,were injected one hour prior to TcdA challenge.Ileal samples were collected to analyze the expression of the P2X7 receptor(by quantitative real-time polymerase chain reaction and immunohistochemistry),the population of myenteric enteric neurons(immunofluorescence),histological damage,intestinal inflammation,cell death(terminal deoxynucleotidyltransferasemediated dUTP-biotin nick end labeling),neuronal loss,and S100B synthesis(immunohistochemistry).RESULTS TcdA upregulated(P<0.05)the expression of the P2X7 receptor gene in the ileal tissues,increasing the level of this receptor in myenteric neurons compared to that in control mice.Comparison with the control mice indicated that TcdA promoted(P<0.05)the loss of myenteric calretinin+(Calr)and choline acetyltransferase+neurons and increased the number of nitrergic+and Calr+neurons expressing the P2X7 receptor.Blockade of the P2X7 receptor decreased TcdAinduced intestinal damage,cytokine release[interleukin(IL)-1β,IL-6,IL-8,and tumor necrosis factor-α],cell death,enteric neuron loss,and S100B synthesis in the mouse ileum.CONCLUSION Our findings demonstrated that TcdA induced the upregulation of the P2X7 receptor,which promoted enteric neuron loss,S100B synthesis,tissue damage,inflammation,and cell death in the mouse ileum.These findings contribute to the future directions in understanding the mechanism involved in intestinal dysfunction reported in patients after C.difficile infection.展开更多
基金grants from the National Natural Science Foundation of China (No.81573745and No.8160140274)Beijing Municipal Natural Science Foundation (No.7172066) Beijing Development Foundation of Traditional Chinese Medicine (QN2016-23).
文摘Background:The nucleotide-binding and oligomerization domain-like receptor protein 3 (NLRP3) inflammasome composed of NLRP3,apoptosis-associated speck-like protein containing CARD (ASC),and caspase-1 is engaged in the inflammatory response of many kidney diseases and can be activated by purinergic 2X7 receptor (P2X7R).This study was conducted to explore whether P2X7R plays a pathogenic role in the podocyte damage of obesity-related glomerulopathy (ORG) and whether this role is mediated by the activation ofNLRP3 inflammasome.Methods:A mouse model of ORG was established by high-fat diet feeding.The conditionally immortalized mouse podocytes were cultured with leptin or with leptin and P2X7R antagonist (KN-62 or A438079).The mRNA and protein expression of the P2X7R and NLRP3 inflammasome components including NLRP3,ASC,and caspase-1,as well as the podocyte-associated molecules including nephrin,podocin,and desmin in mouse renal cortex or cultured mouse podocytes were tested by real-time-polymerase chain reaction and Westem blot analysis,respectively.Results:The significantly upregulated expression of P2X7R and NLRP3 inflammasome components and the NLRP3 inflammasome activation were observed in the renal cortex (in fact their location in podocytes was proved by confocal microscopy) of ORG mice in vivo,which were accompanied with the morphological changes of podocyte damage and the expression changes of podocyte-associated molecules.Similar changes in the expression of P2X7R and NLRP3 inflammasome components as well as in the expression ofpodocyte-associated molecules were also observed in the cultured podocyte studies treated by leptin in vitro,and all of the above changes were significantly attenuated by the P2X7R antagonist KN-62 or A438079.Conclusions:P2X7R could trigger the activation ofNLRP3 inflammasome,and the activated P2X7R/NLRP3 inflammasome in podocytes might be involved in the podocyte damage of ORG.
基金supported by STI2030-Major Projects(No.2022ZD0212200)National Natural Science Foundation of China(No.62305118)+1 种基金Guangdong Basic and Applied Basic Research Foundation(No.2025A1515010953)China Postdoctoral Science Foundation(No.2022M721223).
文摘The brain lymphatic system plays a crucial role in maintaining homeostasis,clearing metabolic waste,and regulating neuroinflammation.Its dysfunction is strongly linked to neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease.In this study,we employed dual-contrast functionalphotoacoustic microscopy to evaluate the impact of lipopolysaccharide-induced central nervous system inflammation on brain lymphatic function and to explore the protective effects of the P2X7 receptor(P2X7R)antagonist.Our findings demonstrated that lipopolysac-charide intervention led to impaired function of the meningeal lymphatic vessels,which was par-tially restored by the P2X7R antagonist,whereas its effects on the glymphatic system and cerebral vessels were minimal.This study further supports the feasibility of photoacoustic microscopy for assessing brain lymphatic function and highlights the therapeutic potential of P2X7R antagonism.These findings suggest that P2X7R may serve as a key target for modulating brain-lymphatic interactions,providing an experimental foundation for developing intervention strategies for neuroinflammatory and neurodegenerative diseases.
文摘OBJECTIVE:to investigate the anti-arthritic effects of lappaconitine(LA)on adjuvant-induced arthritis in Sprague-Dawley rats and its possible involvement in the regulation of M1/M2 macrophage balance through the P2X7 receptor(P2X7r).METHODS:Rats were immunized with complete Freund's adjuvant and then intraperitoneally administered LA(2,4,or 8 mg·kg^(-1)·d^(-1))or methotrexate(0.5 mg/kg per 3 d)for 14 d.The anti-arthritic effects of LA were evaluated through arthritis index(AI)assessment,ankle diameter measurement,and histopathological staining analysis.The analgesic effect of LA on arthritis was measured using mechanical withdrawal threshold testing and gait scoring.The impacts of LA on macrophage polarization,the expression of pro-/anti-inflammatory cytokines and P2X7r were analyzed using quantitative real-time polymerase chain reaction,enzyme-linked immunosorbent assay,and Western blotting.RESULTS:LA treatment significantly reduced AI scores,paw swelling,joint destruction,and inflammatory cell infiltration,and alleviated arthritis pain.Additionally,LA promoted a balanced M1/M2 ratio by increasing the m RNA expression level of M2 marker arginase 1 and decreasing those of M1 markers inducible nitric oxide synthase and interleukin(IL)-1βin synovial tissues.Furthermore,LA lowered the levels of three M1-related cytokines,namely tumor necrosis factor-α,IL-1βand IL-18,and raised the level of the M2-related cytokine IL-10.Further research showed that treatment with LA inhibited the expression of P2X7r.CONCLUSION:Our findings indicate that the notable therapeutic and analgesic effects of LA on AIA rats are exerted through balancing the M1/M2 ratio,probably via P2X7r.
基金The project supported by National Natural Science Foundation of China(81260664,81160538)
文摘OBJECTIVE To investigate the effect of P2X7receptor(P2X7r)inhibition,using a specific inhibitor(A438079)to prevent the development of liver fibrosis on human hepatic stellate cells,LX-2.METHODS The supernatant from lipopolysaccharide(LPS)-stimulated RAW264.7 mouse macrophages was supplemented to LX-2 cells for 24 h.LX-2cells were primed with LPS for 4h and subsequently stimulated for 30 min with 3mmol·L-1 of adenosine 5′-triphosphate(ATP).A438079(10μmol·L-1)was supplemented to LX-2 cells 10 min prior to ATP.RESULTS Directly treated with LPS on LX-2 cells,mRNA expressions of IL-1β,IL-18 and IL-6 were increased,as well as P2X7 r.And caspase-1,ASC and NLRP3 mRNA expressions were increased with LPS stimulation.LPS stimulation also increasedα-SMA and collagenⅠ mRNA expressions.Interestingly treatment of LX-2cells with mediums from LPS-primed RAW264.7mouse macrophages exhibited greater increase of mRNA expressions of above genes than those in LX-2directly treated with LPS.Pretreatment of directly or indirectly LPS-stimulated LX-2 cells with A438079 both suppressed IL-1βmRNA expression.In addition treatment of LPS-primed LX-2 cells with 3mmol·L-1 ATP induced the significant increase of IL-1β,IL-6,caspase-1,pannexin-1,α-SMA and collagenⅠ mRNA expression,the increasing ofα-SMA protein expression and cleavage of IL-1β.These events were significantly suppressed by pretreatment with P2X7 rantagonist A438079.P2X7 rblockade also significantly reduced the protein expression ofα-SMA.CONCLUSION Our results suggest that the involvement of the P2X7r-NLRP3 inflammasome pathway in the secretion of IL-1βfrom extracellular ATP/LPS-stimulated human hepatic stellate cells.This study demonstrated that repression of the P2X7 rrepresents a novel potential therapeutic approach to control liver fibrosis.
基金the National Natural Science Foundation of China(81871852,81200935,81671862,and 81871529)Liaoning Revitalization Talents Program(XLYC1807137)+1 种基金the Scientific Research Foundation for Overseas Scholars of the Education Ministry of China(20151098)the Natural Science Foundation of Liaoning Province,China(20170541030)。
文摘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.
基金supported by the Natural Science Foundation of Guangdong Province,No.S2011010004096
文摘Interleukin-1α and interleukin-1β aggravate neuronal injury by mediating the inf1αmmatory reaction following ischemic/hypoxic brain injury. It remains unclear whether interleukin-1α and interleukin-1β are released by microglia or astrocytes. This study prepared hippocampal slices that were subsequently subjected to oxygen and glucose deprivation. Hematoxylin-eosin staining verified that neurons exhibited hypoxic changes. Results of enzyme-linked immunosorbent assay found that interleukin-1α and interleukin-1β participated in this hypoxic process. Moreover, when hypoxic injury occurred in the hippocampus, the release of interleukin-1α and interleukin-1β was mediated by the P2X4 receptor and P2X7 receptor. Immunofluorescence staining revealed that during ischemia/hypoxia, the P2X4 receptor, P2X7 receptor, interleukin-1α and interleukin-1β expression was detectable in rat hippocampal microglia, but only P2X4 receptor and P2X7 receptor expression was detected in astrocytes. Results suggested that the P2X4 receptor and P2X7 receptor, respectively, mediated interleukin-1α and interleukin-1β released by microglia, resulting in hippocampal ischemic/hypoxic injury. Astrocytes were activated, but did not synthesize or release interleukin-1α and interleukin-1β.
基金supported by a grant from the Natural Science Foundation of Liaoning Province, China (201202050)
文摘Cerebral ischemia is one of the most common diseases resulting in death and disability in aged people. It leads immediately to rapid energy failure, ATP depletion, and ionic imbalance, which increase extracellular ATP levels and accordingly activate P2X7 receptors. These receptors are ATP-gated cation channels and widely distributed in nerve cells, especially in the immunocompetent cells of the brain. Currently, interest in the roles of P2Xz receptors in ischemic brain injury is growing. In this review, we discuss recent research progress on the actions of P2X7 receptors, their possible mechanisms in cerebral ischemia, and the potential therapeutic value of P2X7 receptor antagonists which may provide a new target both for clinical and for research purposes.
基金financially supported by grants from the National Natural Science Foundation of China,No.81371346,81271376Outstanding Postgraduate Fund of Xinxiang Medical UniversityScience and Technology Key Research Project of Henan Provincial Education Department of China,No.14A310019
文摘The present study aimed to explore the mechanism underlying the protective effects of hydrogen sulfide against neuronal damage caused by cerebral ischemia/reperfusion. We established the middle cerebral artery occlusion model in rats via the suture method. Ten minutes after middle cerebral artery occlusion, the animals were intraperitoneally injected with hydrogen sulfide donor compound sodium hydrosulfide. Immunofluorescence revealed that the immunoreactivity of P2X7 in the cerebral cortex and hippocampal CA1 region in rats with cerebral ischemia/reperfusion injury decreased with hydrogen sulfide treatment. Furthermore, treatment of these rats with hydrogen sulfide significantly lowered mortality, the Longa neurological deficit scores, and infarct volume. These results indicate that hydrogen sulfide may be protective in rats with local cerebral ischemia/reperfusion injury by down-regulating the expression of P2X7 receptors.
基金The National Key Research&Development Plan(Grant No.2018YFC0311005)the National Natural Science Foundation of China(Grant No.81473383)+2 种基金the Significant New-Drugs Creation of Science and Technology Major Projects(Grant No.2012ZX09103101-078)the Medical and Health Innovation Project of Chinese Academy of Medical Sciences(Grant No.2016-I2M-3-007)Innovation Fund for Doctoral Students of Beijing Union Medical College(Grant No.2018-1007-04).
文摘Acute kidney injury(AKI)is a common clinical serious illness.Esculin(ES)is a coumarin compound of traditional Chinese medicine Cortex Fraxini.Our previous study has found that ES protects against inflammation and renal damage in diabetic rats.In the present study,we aimed to investigate the effects and the possible mechanism of ES against lipopolysaccharides(LPS)-induced AKI in mice.Renal morphology was observed by H&E staining.Renal function was evaluated by blood urea nitrogen(BUN)level and creatinine content in serum.Inflammatory factor levels were measured by ELISA assay.The inflammatory proteins were analyzed by RT-PCR and Western blotting analysis.The results showed that ES alleviated LPS-induced pathological injury and renal dysfunction,and decreased BUN level and creatinine content in serum.In addition,ES significantly reduced the release of pro-inflammatory factors,including IL-1β,IL-6 and TNF-α,chemokine MCP-1 and cell adhesion molecule ICAM-1.Furthermore,the expressions of inflammatory pathway proteins P2 X7,HMGB1,TLR4 and MyD88 both at the mRNA and protein levels were all down-regulated by ES in the kidney tissue of LPS-challenged mice.These results suggested ES protected against LPS-induced AKI through inhibiting P2 X7 expression and HMGB1/TLR4 inflammatory pathway.
基金Supported by The National Natural Science Foundation of China,No. 81801943Shanghai Pujiang Program,No. 21PJD009The Research Grant for Public Health Key Discipline of Shanghai Municipality,China,No. GWV-10.1-XK26
文摘The intestinal mucosa is a highly compartmentalized structure that forms a directbarrier between the host intestine and the environment, and its dysfunction couldresult in a serious disease. As T cells, which are important components of themucosal immune system, interact with gut microbiota and maintain intestinalhomeostasis, they may be involved in the process of intestinal barrier dysfunction.P2X7 receptor (P2X7R), a member of the P2X receptors family, mediates the effectsof extracellular adenosine triphosphate and is expressed by most innate or adaptiveimmune cells, including T cells. Current evidence has demonstrated thatP2X7R is involved in inflammation and mediates the survival and differentiationof T lymphocytes, indicating its potential role in the regulation of T cell function.In this review, we summarize the available research about the regulatory role andmechanism of P2X7R on the intestinal mucosa-derived T cells in the setting ofintestinal barrier dysfunction.
基金supported by grants from the National Natural Science Foundation of China (31271215, 81770423, 81973945, and 81673766)the Health Vocational and Technical Education Research Program of Jiangsu Province, China (J201506)。
文摘The present study was designed to investigate the mechanisms by which P2X7 receptors(P2X7Rs)mediate the activation of vasopressinergic neurons thereby increasing sympathetic hyperactivity in the paraventricular nucleus(PVN) of the hypothalamus of rats with acute myocardial ischemia(AMI). The left anterior descending branch of the coronary artery was ligated to induce AMI in rats. The rats were pretreated with BBG(brilliant blue G, a P2X7R antagonist), nelivaptan(a vasopressin V1b receptor antagonist), or diphenyleneiodonium(DPI) [an nicotinamide adenine dinucleotide phosphate(NADPH)oxidase inhibitor]. Hemodynamic parameters of the heart were monitored. Myocardial injury and cardiomyocyte apoptosis were assessed. In the PVN of AMI rats, P2X7R mediated microglial activation, while reactive oxygen species(ROS) and NADPH oxidase 2(NOX2) were higher than in the sham group. Intraperitoneal injection of BBG effectively reduced ROS production and vasopressin expression in the PVN of AMI rats. Moreover, both BBG and DPI pretreatment effectively reduced sympathetic hyperactivity and ameliorated AMI injury, as represented by reduced inflammation and apoptosis of cardiomyocytes.Furthermore, microinjection of nelivaptan into the PVN improved cardiac function and reduced the norepinephrine(AE) levels in AMI rats. Collectively, the results suggest that, within the PVN of AMI rats, P2X7R upregulation mediates microglial activation and the overproduction of ROS, which in turn activates vasopressinergic neuron V1b receptors and sympathetic hyperactivity, hence aggravating myocardial injury in the AMI setting.
基金Project supported by the National Natural Science Foundation of China(Nos.81771208 and 81971043)the Health and Family Planning Commission of Wuxi(No.YGZXM1406)+3 种基金the Wuxi Municipal Bureau on Science and Technology(No.CSE31N1614)the Fundamental Research Fund of Wuxi People’s Hospital(No.RKA201720)the Technology for Social Development Project of Kunshan(No.KS1539)China.
文摘Painful diabetic neuropathy(PDN)is a diabetes mellitus complication.Unfortunately,the mechanisms underlying PDN are still poorly understood.Adenosine triphosphate(ATP)-gated P2X7 receptor(P2X7R)plays a pivotal role in non-diabetic neuropathic pain,but little is known about its effects on streptozotocin(STZ)-induced peripheral neuropathy.Here,we explored whether spinal cord P2X7R was correlated with the generation of mechanical allodynia(MA)in STZ-induced type 1 diabetic neuropathy in mice.MA was assessed by measuring paw withdrawal thresholds and western blotting.Immunohistochemistry was applied to analyze the protein expression levels and localization of P2X7R.STZ-induced mice expressed increased P2X7R in the dorsal horn of the lumbar spinal cord during MA.Mice injected intrathecally with a selective antagonist of P2X7R and P2X7R knockout(KO)mice both presented attenuated progression of MA.Double-immunofluorescent labeling demonstrated that P2X7R-positive cells were mostly co-expressed with Iba1(a microglia marker).Our results suggest that P2X7R plays an important role in the development of MA and could be used as a cellular target for treating PDN.
基金supported by the National Natural Science Foundation of China,No.30471657
文摘We hypothesized that the P2X7 receptor may be the target of isoflurane, so we investigated the roles of the P2X7 receptor and inositol triphosphate receptor in calcium overload and neuronal apoptosis induced by isoflurane in cultured embryonic rat hippocampal neurons. Results showed that isoflurane induced widespread neuronal apoptosis and significantly increased cytoplasmic Ca^2＋ Blockade of P2X7 receptors or removal of extracellular Ca^2＋ combined with blockade of inositol triphosphate receptors completely inhibited apoptosis or increase in cytoplasmic Ca^2＋. Removal of extracellular Ca^2＋ or blockade of inositol triphosphate receptor alone could partly inhibit these effects of isoflurane. Isoflurane could directly activate P2X7-gated channels and induce inward currents, but did not affect the expression of P2X7 receptor protein in neurons. These findings indicate that the mechanism by which isoflurane induced neuronal apoptosis in rat developing brain was mediated by intracellular calcium overload, which was caused by P2X7 receptor mediated calcium influx and inositol triphosphate receptor mediated calcium release.
基金Supported by the Sao Paulo Research (FAPESP, Brazil),No. 2014/25927-2 and No. 2018/07862-1the National Council for Scientific and Technological Development (CNPq, Brazil)
文摘The enteric nervous system(ENS)consists of thousands of small ganglia arranged in the submucosal and myenteric plexuses,which can be negatively affected by Crohn’s disease and ulcerative colitis-inflammatory bowel diseases(IBDs).IBDs are complex and multifactorial disorders characterized by chronic and recurrent inflammation of the intestine,and the symptoms of IBDs may include abdominal pain,diarrhea,rectal bleeding,and weight loss.The P2X7 receptor has become a promising therapeutic target for IBDs,especially owing to its wide expression and,in the case of other purinergic receptors,in both human and model animal enteric cells.However,little is known about the actual involvement between the activation of the P2X7 receptor and the cascade of subsequent events and how all these activities associated with chemical signals interfere with the functionality of the affected or treated intestine.In this review,an integrated view is provided,correlating the structural organization of the ENS and the effects of IBDs,focusing on cellular constituents and how therapeutic approaches through the P2X7 receptor can assist in both protection from damage and tissue preservation.
基金supported by the National Natural Science Foundation of China, No. 81072242the Excellent Supervisor & Yat-Sen Creative Talent Development Program of Sun Yat-sen University
文摘Previous studies have confirmed that oxidized adenosine triphosphate, a P2X7 receptor antagonist, attenuates lipopolysaccharide-mediated microglial activation and inflammatory expression following neuronal damage in rat brain. NaCI and temperature may affect the potency of oxidized adenosine triphosphate. Brilliant blue G is a derivative of a widely used food additive and has little toxicity. This study explored the effects of brilliant blue G, a selective P2X7 receptor antagonist, on microglial activation and inflammation. Results demonstrated that brilliant blue G inhibited the release of cydooxygenase-2 and interleukin-6 in BV2 cells. Immunofluorescence displayed that brilliant blue G could suppress lipopolysaccharide-induced microglial activation. This study used RNA interference to block P2X7 receptor expression and found that small interfering RNA also suppressed the release of cyclooxygenase-2 and interleukin-6 in BV2 cells. These results suggested that downregulation of the P2X7 receptor by brilliant blue G was involved in the inhibition of microglial activation and inflammation.
文摘Acknowledgments： I would like to express my appreciation to Professor Puro DG for leading me to this research topic during my stay as a research fellow in his laboratory at the University of Michigan in 2001, and also to Professor Ikeda T forgiving me the opportunity to study abroad and then to continue to investigate this topic in the Department of Ophthalmology at Osaka Medical College, lapan.
基金Supported by Foundation Sao Paulo Research,No.2014/25927-2 and No.2018/07862-1Coordenacao de Aperfeicoamento de Pessoal de Nível SuperiorConselho Nacional de Desenvolvimento Científico e Tecnológico。
文摘BACKGROUND The P2X7 receptor is expressed by enteric neurons and enteric glial cells.Studies have demonstrated that administration of a P2X7 receptor antagonist,brilliant blue G(BBG),prevents neuronal loss.AIM To report the effects of BBG in ileum enteric neurons immunoreactive(ir)following experimental ulcerative colitis in Rattus norvegicus albinus.METHODS 2,4,6-trinitrobenzene sulfonic acid(TNBS group,n=5)was injected into the distal colon.BBG(50 mg/kg,BBG group,n=5)or vehicle(sham group,n=5)was given subcutaneously 1 h after TNBS.The animals were euthanized after 24 h,and the ileum was removed.Immunohistochemistry was performed on the myenteric plexus to evaluate immunoreactivity for P2X7 receptor,neuronal nitric oxide synthase(nNOS),choline acetyltransferase(ChAT),HuC/D and glial fibrillary acidic protein.RESULTS The numbers of nNOS-,ChAT-,HuC/D-ir neurons and glial fibrillary acidic protein-ir glial cells were decreased in the TNBS group and recovered in the BBG group.The neuronal profile area(μm^2)demonstrated that nNOS-ir neurons decreased in the TNBS group and recovered in the BBG group.There were no differences in the profile areas of ChAT-and HuC/D-ir neurons.CONCLUSION Our data conclude that ileum myenteric neurons and glial cells were affected by ulcerative colitis and that treatment with BBG had a neuroprotective effect.Thus,these results demonstrate that the P2X7 receptor may be an important target in therapeutic strategies.
文摘A family of novel squaramides/sulfamides based on 1,2-alkamine was developed as chiral bifunctional catalysts to promote the asymmetric alcoholysis of meso cyclic anhydrides. The hemiesters were obtained in high yield with up to 93% ee. The usefulness of this methodology was demonstrated in the asymmetric synthesis of the key intermediate of P2X7 receptor antagonists.
基金Supported by the National Council for Scientific and Technological Development,No.168015/2018-8the São Paulo Research Foundation,No.2014/25927-2 and No.2018/07862-1.
文摘BACKGROUND The literature indicates that the enteric nervous system is affected in inflammatory bowel diseases(IBDs)and that the P2X7 receptor triggers neuronal death.However,the mechanism by which enteric neurons are lost in IBDs is unknown.AIM To study the role of the caspase-3 and nuclear factor kappa B(NF-κB)pathways in myenteric neurons in a P2X7 receptor knockout(KO)mouse model of IBDs.METHODS Forty male wild-type(WT)C57BL/6 and P2X7 receptor KO mice were euthanized 24 h or 4 d after colitis induction by 2,4,6-trinitrobenzene sulfonic acid(colitis group).Mice in the sham groups were injected with vehicle.The mice were divided into eight groups(n=5):The WT sham 24 h and 4 d groups,the WT colitis 24 h and 4 d groups,the KO sham 24 h and 4 d groups,and the KO colitis 24 h and 4 d groups.The disease activity index(DAI)was analyzed,the distal colon was collected for immunohistochemistry analyses,and immunofluorescence was performed to identify neurons immunoreactive(ir)for calretinin,P2X7 receptor,cleaved caspase-3,total caspase-3,phospho-NF-κB,and total NF-κB.We analyzed the number of calretinin-ir and P2X7 receptor-ir neurons per ganglion,the neuronal profile area(μm^(2)),and corrected total cell fluorescence(CTCF).RESULTS Cells double labeled for calretinin and P2X7 receptor,cleaved caspase-3,total caspase-3,phospho-NF-κB,or total NF-κB were observed in the WT colitis 24 h and 4 d groups.The number of calretinin-ir neurons per ganglion was decreased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(2.10±0.13 vs 3.33±0.17,P<0.001;2.92±0.12 vs 3.70±0.11,P<0.05),but was not significantly different between the KO groups.The calretinin-ir neuronal profile area was increased in the WT colitis 24 h group compared to the WT sham 24 h group(312.60±7.85 vs 278.41±6.65,P<0.05),and the nuclear profile area was decreased in the WT colitis 4 d group compared to the WT sham 4 d group(104.63±2.49 vs 117.41±1.14,P<0.01).The number of P2X7 receptor-ir neurons per ganglion was decreased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(19.49±0.35 vs 22.21±0.18,P<0.001;20.35±0.14 vs 22.75±0.51,P<0.001),and no P2X7 receptor-ir neurons were observed in the KO groups.Myenteric neurons showed ultrastructural changes in the WT colitis 24 h and 4 d groups and in the KO colitis 24 h group.The cleaved caspase-3 CTCF was increased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(485949±14140 vs 371371±16426,P<0.001;480381±11336 vs 378365±4053,P<0.001),but was not significantly different between the KO groups.The total caspase-3 CTCF,phospho-NF-κB CTCF,and total NF-κB CTCF were not significantly different among the groups.The DAI was recovered in the KO groups.Furthermore,we demonstrated that the absence of the P2X7 receptor attenuated inflammatory infiltration,tissue damage,collagen deposition,and the decrease in the number of goblet cells in the distal colon.CONCLUSION Ulcerative colitis affects myenteric neurons in WT mice but has a weaker effect in P2X7 receptor KO mice,and neuronal death may be associated with P2X7 receptor-mediated caspase-3 activation.The P2X7 receptor can be a therapeutic target for IBDs.
基金Supported by PRONEX CNPq/FUNCAP,No.PR2-0101-00060.01.00/15Sao Paulo Research Foundation(FAPESP),No.2014/25927-2 and No.2018/07862-1.
文摘Clostridioides difficile(C.difficile)is the most common pathogen causing health care-associated infections.C.difficile TcdA and TcdB have been shown to activate enteric neurons;however,what population of these cells is more profoundly influenced and the mechanism underlying these effects remain unknown.AIM To characterize a specific population of TcdA-affected myenteric neurons and investigate the role of the P2X7 receptor in TcdA-induced ileal inflammation,cell death,and the changes in the enteric nervous system in mice.METHODS Swiss mice were used to model TcdA-induced ileitis in ileal loops exposed to TcdA(50μg/Loop)for 4 h.To investigate the role of the P2X7 receptor,Brilliant Blue G(50 mg/kg,i.p.),which is a nonspecific P2X7 receptor antagonist,or A438079(0.7μg/mouse,i.p.),which is a competitive P2X7 receptor antagonist,were injected one hour prior to TcdA challenge.Ileal samples were collected to analyze the expression of the P2X7 receptor(by quantitative real-time polymerase chain reaction and immunohistochemistry),the population of myenteric enteric neurons(immunofluorescence),histological damage,intestinal inflammation,cell death(terminal deoxynucleotidyltransferasemediated dUTP-biotin nick end labeling),neuronal loss,and S100B synthesis(immunohistochemistry).RESULTS TcdA upregulated(P<0.05)the expression of the P2X7 receptor gene in the ileal tissues,increasing the level of this receptor in myenteric neurons compared to that in control mice.Comparison with the control mice indicated that TcdA promoted(P<0.05)the loss of myenteric calretinin+(Calr)and choline acetyltransferase+neurons and increased the number of nitrergic+and Calr+neurons expressing the P2X7 receptor.Blockade of the P2X7 receptor decreased TcdAinduced intestinal damage,cytokine release[interleukin(IL)-1β,IL-6,IL-8,and tumor necrosis factor-α],cell death,enteric neuron loss,and S100B synthesis in the mouse ileum.CONCLUSION Our findings demonstrated that TcdA induced the upregulation of the P2X7 receptor,which promoted enteric neuron loss,S100B synthesis,tissue damage,inflammation,and cell death in the mouse ileum.These findings contribute to the future directions in understanding the mechanism involved in intestinal dysfunction reported in patients after C.difficile infection.
