Purinergic receptors are among the first cell surface receptors expressed during embryonic development （Burnstock and Ulrich, 2011）. These are characterized based on their pharmacological properties of being activat...Purinergic receptors are among the first cell surface receptors expressed during embryonic development （Burnstock and Ulrich, 2011）. These are characterized based on their pharmacological properties of being activated by adenosine or purine/pyrimidine nucleotides as P1 and P2 receptors. P2 receptors are further classified by their structure as P2Y metabotropic and P2X ionotropic receptors.展开更多
Adenosine triphosphate(ATP)is well-known as a universal source of energy in living cells.Less known is that this molecule has a variety of important signaling func-tions:it activates a variety of specific metabotropic...Adenosine triphosphate(ATP)is well-known as a universal source of energy in living cells.Less known is that this molecule has a variety of important signaling func-tions:it activates a variety of specific metabotropic(P2Y)and ionotropic(P2X)receptors in neuronal and non-neu-ronal cell membranes.So,a wide variety of signaling func-tions well fits the ubiquitous presence of ATP in the tissues.Even more ubiquitous are protons.Apart from the unspe-cific interaction of protons with any protein,many physi-ological processes are affected by protons acting on specific ionotropic receptors--acid-sensing ion channels(ASICs).Both protons(acidification)and ATP are locally elevated in various pathological states.Using these fundamentally important molecules as agonists,ASICs and P2X receptors signal a variety of major brain pathologies.Here we briefly outline the physiological roles of ASICs and P2X receptors,focusing on the brain pathologies involving these receptors.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 expression of P2X receptors on rat intracardiac and paratracheal ganglion neurons. Methods： For preparation of intracardiac neurons, hearts were excised, the atria were separated and th...Objective： To investigate the expression of P2X receptors on rat intracardiac and paratracheal ganglion neurons. Methods： For preparation of intracardiac neurons, hearts were excised, the atria were separated and the medial region containing intracardiac ganglia was isolated and cut into pieces. For preparation of paratracheal neurons, the tracheas were removed and the superficial membranous layer containing paratracheal ganglia was rapidly isolated. Intracardiac and paratracheal ganglion neurons were dissociated after digestion by collagenase and trypsin. Whole-cell patch clamp recording was used to identify the pharmacological properties of P2X receptors in cultured neurons. Results：Neurons from these two ganglia responded to ATP with a rapidly activating, sustained inward current, αβ-meATP failed to evoke any re- sponses in paratracheal ganglion neurons while a few of intracardiac ganglion neurons responded to αβ- meATP with a tiny sustained inward current. ADP and UTP had no effect on intracardiac neurons. Lowering pH potentiated ATP responses in neurons from these two ganglia whereas increasing pH inhibited ATP responses. Co-application of Zn^2＋ potentiated ATP responses in intracardiac and paratracheal ganglion neurons. Conclusion： The receptor subtypes involved in intracardiac and paratracheal ganglia appear to be homomeric P2X2, while heteromeric P2X2/3 could not be completely excluded from intracardiac neurons.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
Electroacupuncture at Shangjuxu （ST37） and Tianshu （ST25） was reported to improve visceral hypersensitivity in rats, Colorectal distension was utilized to generate a rat model of chronic visceral hypersensitivity ...Electroacupuncture at Shangjuxu （ST37） and Tianshu （ST25） was reported to improve visceral hypersensitivity in rats, Colorectal distension was utilized to generate a rat model of chronic visceral hypersensitivity in irritable bowel syndrome, Results showed that abdominal withdrawal reflex scores noticeably increased after model establishment. Simultaneously, P2X4 receptor immunore- activity significantly increased in the colon and spinal cord. Electroacupuncture and pinaverium bromide therapy both markedly decreased abdominal withdrawal reflex scores in rats with visceral hypersensitivity, and significantly decreased P2X4 receptor immunoreactivity in the colon and spinal cord. These data suggest that electroacupuncture treatment can improve visceral hypersensitivity in rats with irritable bowel syndrome by diminishing P2X4 receptor immunoreactivity in the colon and spinal cord,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 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
AIM:To investigate the colocalization,density and profile of neuronal areas of enteric neurons in the ileum of male obese mice.METHODS:The small intestinal samples of male mice in an obese group(OG)(C57BL/6J ob/ob)and...AIM:To investigate the colocalization,density and profile of neuronal areas of enteric neurons in the ileum of male obese mice.METHODS:The small intestinal samples of male mice in an obese group(OG)(C57BL/6J ob/ob)and a control group(CG)(+/+)were used.The tissues were analyzed using a double immunostaining technique for immunoreactivity(ir)of the P2X2 receptor,nitric oxide synthase(NOS),choline acetyl transferase(ChAT)and calretinin(Calr).Also,we investigated the density and profile of neuronal areas of the NOS-,ChAT-and Calrir neurons in the myenteric plexus.Myenteric neurons were labeled using an NADH-diaphorase histochemical staining method.RESULTS:The analysis demonstrated that the P2X2receptor was expressed in the cytoplasm and in the nuclear and cytoplasmic membranes only in the CG.Neuronal density values(neuron/cm2)decreased 31%(CG:6579±837;OG:4556±407)and 16.5%(CG:7796±528;OG:6513±610)in the NOS-ir and calretininir neurons in the OG,respectively(P<0.05).Density of ChAT-ir(CG:6200±310;OG:8125±749)neurons significantly increased 31%in the OG(P<0.05).Neuron size studies demonstrated that NOS,ChAT,and Calr-ir neurons did not differ significantly between the CG and OG groups.The examination of NADH-diaphorase-positive myenteric neurons revealed an overall similarity between the OG and CG.CONCLUSION:Obesity may exert its effects by promoting a decrease in P2X2 receptor expression and modifications in the density of the NOS-ir,ChAT-ir and CalR-ir myenteric neurons.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
AIM:To examine whether the ob/ob mouse model of obesity is accompanied by enteric nervous system ab-normalities such as altered motility METHODS:The study examined the distribution of the P2X 2 receptor (P2X 2 R) in m...AIM:To examine whether the ob/ob mouse model of obesity is accompanied by enteric nervous system ab-normalities such as altered motility METHODS:The study examined the distribution of the P2X 2 receptor (P2X 2 R) in myenteric neurons of female ob/ob mice. Specifically, we used immunohistochemistry to analyze the co-expression of the P2X 2 R with neuronal nitric oxide synthase (nNOS), choline acetyltrans-ferase (ChAT), and calretinin (CalR) in neurons of the small intestine myenteric plexus in ob/ob and control female mice In these sections, we used scanning confocal microscopy to analyze the co-localization of these markers as well as the neuronal density (cm 2 ) and area profile (μm2) of P2X 2 R-positive neurons In addition, enteric neurons were labeled using the nicotinamide adenine dinucleotide (NA H) diaphorase method and analyzed with light microscopy as an alternate means by which to analyze neuronal density and areaRESULTS:In the present study, we observed a 29 6% increase in the body weight of the ob/ob animals (OG) compared to the control group (CG) In addition, the average small intestine area was increased by approxi-mately 29 6% in the OG compared to the CG Immu-noreactivity (IR) for the P2X 2 R, nNOS, ChAT and CalR was detectable in the myenteric plexus, as well as in the smooth muscle, in both groups This IR appeared to be mainly cytoplasmic and was also associated with the cell membrane of the myenteric plexus neurons, where it outlined the neuronal cell bodies and their processes P2X 2 R-IR was observed to co-localize 100% with that for nNOS, ChAT and CalR in neurons of both groups In the ob/ob group, however, we observed that the neuronal density (neuron/cm 2 ) of P2X 2 R-IR cells was in-creased by 62% compared to CG, while that of NOS-IR and ChAT-IR neurons was reduced by 49% and 57%, respectively, compared to control mice The neuronal density of CalR-IR neurons was not different between the groups Morphometric studies further demonstrated that the cell body profile area (μm2) of nNOS-IR, ChAT-IR and CalR-IR neurons was increased by 34%, 20% and 55%, respectively, in the OG compared to controls Staining for NA H diaphorase activity is widely used to detect alterations in the enteric nervous system; however, our qualitative examination of NA H-diaphorase positive neurons in the myenteric ganglia revealed an overall similarity between the two groups CONCLUSION:We demonstrate increases in P2X2R expression and alterations in nNOS, ChAT and CalR IR in ileal myenteric neurons of female ob/ob mice compared to wild-type controls.展开更多
Purinergic receptors have been reported to be involved in brain disorders.In this study,we explored their roles and mechanisms underlying the memory impairment in rats with type 2 diabetes mellitus(T2 DM).T2 DM rats e...Purinergic receptors have been reported to be involved in brain disorders.In this study,we explored their roles and mechanisms underlying the memory impairment in rats with type 2 diabetes mellitus(T2 DM).T2 DM rats exhibited a worse performance in the T-maze and Morris water maze(MWM) than controls.Microglia positive for P2 X purinoceptor 4(P2 X4 R) in the hippocampus were reduced and activated microglia were increased in T2 DM rats.Long Amplicon PCR(LA-PCR) showed that DNA amplification of the p2 x4 r gene in the hippocampus was lower in T2 DM rats.Minocycline significantly reduced the number of activated microglia and the mean distance traveled by T2 DM rats in the MWM.Most importantly,P2 X4 R overexpression suppressed the activated microglia and rescued the memory impairment of T2 DM rats.Overall,T2 DM led to excessive activation of microglia in the hippocampus,partly through the DNA damagemediated downregulation of P2 X4 Rs,thus contributing to memory impairment.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
Objective:To investigate whether the activation of p38MAPK is involved in the neuropathic pain induced by P2X4 receptor,and the effects of activated P2X4 receptor and p38MAPK on expression of brain-derived neurotrophi...Objective:To investigate whether the activation of p38MAPK is involved in the neuropathic pain induced by P2X4 receptor,and the effects of activated P2X4 receptor and p38MAPK on expression of brain-derived neurotrophic factor (BDNF) in the chronic neuropathic pain.Methods:Lumbar intrathecal catheters were chronically implanted in male Sprague-Dawley rats.The right sciatic nerve was loosely ligated proximal to the sciatica's trifurcation at approximately 1.0 mm intervals with 4-0 silk sutures.The microglia inhibitor minocycline,P2X4 antagonist (TNP-ATP) and p38MAPK inhibitor (SB203580) were intrathecally administered every 12 h,3 d post-chronic constriction injury (CCI).Mechanical nociceptive thresholds were assessed with the paw withdrawal threshold (PWT) to von Frey filaments.The expression of P2X4 and BDNF were assessed by both immunohistochemical analysis and RT-PCR.Results:Intrathecal injection of minocycline or TNP-ATP or SB203580 significantly attenuated CCI-induced mechanical allodynia.The time courses of P2X4 receptor and BDNF expression were increased at all points after CCI and reached a peak level on postoperative d 7.Intrathecal injection of minocycline or TNP-ATP or SB203580 markedly suppressed the increase of CCI-induced P2X4 receptor and BDNF expression in the spinal cord.Conclusion:The activation of P2X4 receptor BDNF pathways contributes to neuropathic pain in CCI rats,and the activation of p38MAPK is involved in the neuropathic pain induced by P2X4 receptor.展开更多
Schwann cell transplantation is a promising method to promote neural repair, and can be used for peripheral nerve protection and myelination. Microcapsule technology largely mitigates immune rejection of transplanted ...Schwann cell transplantation is a promising method to promote neural repair, and can be used for peripheral nerve protection and myelination. Microcapsule technology largely mitigates immune rejection of transplanted cells. We previously showed that microencapsulated olfactory ensheathing cells can reduce neuropathic pain and we hypothesized that microencapsulated Schwann cells can also inhibit neuropathic pain. Rat Schwann cells were cultured by subculture and then microencapsulated and were tested using a rat chronic constriction injury（CCI） neuropathic pain model. CCI rats were treated with Schwann cells or microencapsulated Schwann cells and were compared with sham and CCI groups. Mechanical withdrawal threshold and thermal withdrawal latency were assessed preoperatively and at 1, 3, 5, 7, 9, 11 and 14 days postoperatively. The expression of P2X3 receptors in L4-5 dorsal root ganglia of the different groups was detected by double-label immunofluorescence on day 14 after surgery. Compared with the chronic constriction injury group, mechanical withdrawal threshold and thermal withdrawal latency were higher, but the expression of P2X3 receptors was remarkably decreased in rats treated with Schwann cells and microencapsulated Schwann cells, especially in the rats transplanted with microencapsulated Schwann cells. The above data show that microencapsulated Schwann cell transplantation inhibits P2X3 receptor expression in L4-5 dorsal root ganglia and neuropathic pain.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
基金support from Fundacao de Amparo à Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)+2 种基金the Provost’s Office for Research of the University of Sao Paulo, Grant number: 2011.1.9333.1.3 (NAPNA-USP)support from the German Research Council (IL 20/182, RI 2092/1-2, IL 20/21-1)the Sino-German Centre for the Support of Science (GZ 919)
文摘Purinergic receptors are among the first cell surface receptors expressed during embryonic development （Burnstock and Ulrich, 2011）. These are characterized based on their pharmacological properties of being activated by adenosine or purine/pyrimidine nucleotides as P1 and P2 receptors. P2 receptors are further classified by their structure as P2Y metabotropic and P2X ionotropic receptors.
基金supported by the National Research Foundation of Ukraine(https:/nrfu.org.ua/en/,2020.02/0263)Die Deutsche Forschungsgemeinschaft(https://www.dfg.del,441694049).
文摘Adenosine triphosphate(ATP)is well-known as a universal source of energy in living cells.Less known is that this molecule has a variety of important signaling func-tions:it activates a variety of specific metabotropic(P2Y)and ionotropic(P2X)receptors in neuronal and non-neu-ronal cell membranes.So,a wide variety of signaling func-tions well fits the ubiquitous presence of ATP in the tissues.Even more ubiquitous are protons.Apart from the unspe-cific interaction of protons with any protein,many physi-ological processes are affected by protons acting on specific ionotropic receptors--acid-sensing ion channels(ASICs).Both protons(acidification)and ATP are locally elevated in various pathological states.Using these fundamentally important molecules as agonists,ASICs and P2X receptors signal a variety of major brain pathologies.Here we briefly outline the physiological roles of ASICs and P2X receptors,focusing on the brain pathologies involving these receptors.
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Supported by the National Natural Foundation of China (No. 30570597)
文摘Objective： To investigate the expression of P2X receptors on rat intracardiac and paratracheal ganglion neurons. Methods： For preparation of intracardiac neurons, hearts were excised, the atria were separated and the medial region containing intracardiac ganglia was isolated and cut into pieces. For preparation of paratracheal neurons, the tracheas were removed and the superficial membranous layer containing paratracheal ganglia was rapidly isolated. Intracardiac and paratracheal ganglion neurons were dissociated after digestion by collagenase and trypsin. Whole-cell patch clamp recording was used to identify the pharmacological properties of P2X receptors in cultured neurons. Results：Neurons from these two ganglia responded to ATP with a rapidly activating, sustained inward current, αβ-meATP failed to evoke any re- sponses in paratracheal ganglion neurons while a few of intracardiac ganglion neurons responded to αβ- meATP with a tiny sustained inward current. ADP and UTP had no effect on intracardiac neurons. Lowering pH potentiated ATP responses in neurons from these two ganglia whereas increasing pH inhibited ATP responses. Co-application of Zn^2＋ potentiated ATP responses in intracardiac and paratracheal ganglion neurons. Conclusion： The receptor subtypes involved in intracardiac and paratracheal ganglia appear to be homomeric P2X2, while heteromeric P2X2/3 could not be completely excluded from intracardiac neurons.
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 National Natural Science Foundation of China,No.30973783the Open Research Fund of Zhejiang First-foremost Key Subject--Acupuncture & Moxibustion,No.ZTK2010A01the scientific research grants of Shanghai Health Bureau,No.2009209
文摘Electroacupuncture at Shangjuxu （ST37） and Tianshu （ST25） was reported to improve visceral hypersensitivity in rats, Colorectal distension was utilized to generate a rat model of chronic visceral hypersensitivity in irritable bowel syndrome, Results showed that abdominal withdrawal reflex scores noticeably increased after model establishment. Simultaneously, P2X4 receptor immunore- activity significantly increased in the colon and spinal cord. Electroacupuncture and pinaverium bromide therapy both markedly decreased abdominal withdrawal reflex scores in rats with visceral hypersensitivity, and significantly decreased P2X4 receptor immunoreactivity in the colon and spinal cord. These data suggest that electroacupuncture treatment can improve visceral hypersensitivity in rats with irritable bowel syndrome by diminishing P2X4 receptor immunoreactivity in the colon and spinal cord,
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Supported by Sao Paulo Research Foundation(FAPESP/Sao Paulo Research Foundation/Proc:05/04752-0)and CAPES Fellowship
文摘AIM:To investigate the colocalization,density and profile of neuronal areas of enteric neurons in the ileum of male obese mice.METHODS:The small intestinal samples of male mice in an obese group(OG)(C57BL/6J ob/ob)and a control group(CG)(+/+)were used.The tissues were analyzed using a double immunostaining technique for immunoreactivity(ir)of the P2X2 receptor,nitric oxide synthase(NOS),choline acetyl transferase(ChAT)and calretinin(Calr).Also,we investigated the density and profile of neuronal areas of the NOS-,ChAT-and Calrir neurons in the myenteric plexus.Myenteric neurons were labeled using an NADH-diaphorase histochemical staining method.RESULTS:The analysis demonstrated that the P2X2receptor was expressed in the cytoplasm and in the nuclear and cytoplasmic membranes only in the CG.Neuronal density values(neuron/cm2)decreased 31%(CG:6579±837;OG:4556±407)and 16.5%(CG:7796±528;OG:6513±610)in the NOS-ir and calretininir neurons in the OG,respectively(P<0.05).Density of ChAT-ir(CG:6200±310;OG:8125±749)neurons significantly increased 31%in the OG(P<0.05).Neuron size studies demonstrated that NOS,ChAT,and Calr-ir neurons did not differ significantly between the CG and OG groups.The examination of NADH-diaphorase-positive myenteric neurons revealed an overall similarity between the OG and CG.CONCLUSION:Obesity may exert its effects by promoting a decrease in P2X2 receptor expression and modifications in the density of the NOS-ir,ChAT-ir and CalR-ir myenteric neurons.
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 So Paulo Research Foundation (FAPESP), Proc 05/04752-0
文摘AIM:To examine whether the ob/ob mouse model of obesity is accompanied by enteric nervous system ab-normalities such as altered motility METHODS:The study examined the distribution of the P2X 2 receptor (P2X 2 R) in myenteric neurons of female ob/ob mice. Specifically, we used immunohistochemistry to analyze the co-expression of the P2X 2 R with neuronal nitric oxide synthase (nNOS), choline acetyltrans-ferase (ChAT), and calretinin (CalR) in neurons of the small intestine myenteric plexus in ob/ob and control female mice In these sections, we used scanning confocal microscopy to analyze the co-localization of these markers as well as the neuronal density (cm 2 ) and area profile (μm2) of P2X 2 R-positive neurons In addition, enteric neurons were labeled using the nicotinamide adenine dinucleotide (NA H) diaphorase method and analyzed with light microscopy as an alternate means by which to analyze neuronal density and areaRESULTS:In the present study, we observed a 29 6% increase in the body weight of the ob/ob animals (OG) compared to the control group (CG) In addition, the average small intestine area was increased by approxi-mately 29 6% in the OG compared to the CG Immu-noreactivity (IR) for the P2X 2 R, nNOS, ChAT and CalR was detectable in the myenteric plexus, as well as in the smooth muscle, in both groups This IR appeared to be mainly cytoplasmic and was also associated with the cell membrane of the myenteric plexus neurons, where it outlined the neuronal cell bodies and their processes P2X 2 R-IR was observed to co-localize 100% with that for nNOS, ChAT and CalR in neurons of both groups In the ob/ob group, however, we observed that the neuronal density (neuron/cm 2 ) of P2X 2 R-IR cells was in-creased by 62% compared to CG, while that of NOS-IR and ChAT-IR neurons was reduced by 49% and 57%, respectively, compared to control mice The neuronal density of CalR-IR neurons was not different between the groups Morphometric studies further demonstrated that the cell body profile area (μm2) of nNOS-IR, ChAT-IR and CalR-IR neurons was increased by 34%, 20% and 55%, respectively, in the OG compared to controls Staining for NA H diaphorase activity is widely used to detect alterations in the enteric nervous system; however, our qualitative examination of NA H-diaphorase positive neurons in the myenteric ganglia revealed an overall similarity between the two groups CONCLUSION:We demonstrate increases in P2X2R expression and alterations in nNOS, ChAT and CalR IR in ileal myenteric neurons of female ob/ob mice compared to wild-type controls.
基金supported by grants from the National Natural Science Foundation of China (31730040,81801115, and 81920108016)the China Postdoctoral Science Foundation (2018M642304)the Priority Academic Program Development of Jiangsu Higher Education Institutions of China。
文摘Purinergic receptors have been reported to be involved in brain disorders.In this study,we explored their roles and mechanisms underlying the memory impairment in rats with type 2 diabetes mellitus(T2 DM).T2 DM rats exhibited a worse performance in the T-maze and Morris water maze(MWM) than controls.Microglia positive for P2 X purinoceptor 4(P2 X4 R) in the hippocampus were reduced and activated microglia were increased in T2 DM rats.Long Amplicon PCR(LA-PCR) showed that DNA amplification of the p2 x4 r gene in the hippocampus was lower in T2 DM rats.Minocycline significantly reduced the number of activated microglia and the mean distance traveled by T2 DM rats in the MWM.Most importantly,P2 X4 R overexpression suppressed the activated microglia and rescued the memory impairment of T2 DM rats.Overall,T2 DM led to excessive activation of microglia in the hippocampus,partly through the DNA damagemediated downregulation of P2 X4 Rs,thus contributing to memory impairment.
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 Natural Science Foundation of Shanghai,China(No. 08ZR1405000)
文摘Objective:To investigate whether the activation of p38MAPK is involved in the neuropathic pain induced by P2X4 receptor,and the effects of activated P2X4 receptor and p38MAPK on expression of brain-derived neurotrophic factor (BDNF) in the chronic neuropathic pain.Methods:Lumbar intrathecal catheters were chronically implanted in male Sprague-Dawley rats.The right sciatic nerve was loosely ligated proximal to the sciatica's trifurcation at approximately 1.0 mm intervals with 4-0 silk sutures.The microglia inhibitor minocycline,P2X4 antagonist (TNP-ATP) and p38MAPK inhibitor (SB203580) were intrathecally administered every 12 h,3 d post-chronic constriction injury (CCI).Mechanical nociceptive thresholds were assessed with the paw withdrawal threshold (PWT) to von Frey filaments.The expression of P2X4 and BDNF were assessed by both immunohistochemical analysis and RT-PCR.Results:Intrathecal injection of minocycline or TNP-ATP or SB203580 significantly attenuated CCI-induced mechanical allodynia.The time courses of P2X4 receptor and BDNF expression were increased at all points after CCI and reached a peak level on postoperative d 7.Intrathecal injection of minocycline or TNP-ATP or SB203580 markedly suppressed the increase of CCI-induced P2X4 receptor and BDNF expression in the spinal cord.Conclusion:The activation of P2X4 receptor BDNF pathways contributes to neuropathic pain in CCI rats,and the activation of p38MAPK is involved in the neuropathic pain induced by P2X4 receptor.
基金supported by the National Natural Science Foundation of China,No.81760418 and 81260190the Natural Science Foundation of Jiangxi Province,No.20132BAB205023,20151BAB205022+1 种基金a grant from Science and Technology Research Project of Jiangxi Education Department,No.GJJ13159a grant from the Science and Technology Program of Department of Health of Jiangxi Province,No.20173010
文摘Schwann cell transplantation is a promising method to promote neural repair, and can be used for peripheral nerve protection and myelination. Microcapsule technology largely mitigates immune rejection of transplanted cells. We previously showed that microencapsulated olfactory ensheathing cells can reduce neuropathic pain and we hypothesized that microencapsulated Schwann cells can also inhibit neuropathic pain. Rat Schwann cells were cultured by subculture and then microencapsulated and were tested using a rat chronic constriction injury（CCI） neuropathic pain model. CCI rats were treated with Schwann cells or microencapsulated Schwann cells and were compared with sham and CCI groups. Mechanical withdrawal threshold and thermal withdrawal latency were assessed preoperatively and at 1, 3, 5, 7, 9, 11 and 14 days postoperatively. The expression of P2X3 receptors in L4-5 dorsal root ganglia of the different groups was detected by double-label immunofluorescence on day 14 after surgery. Compared with the chronic constriction injury group, mechanical withdrawal threshold and thermal withdrawal latency were higher, but the expression of P2X3 receptors was remarkably decreased in rats treated with Schwann cells and microencapsulated Schwann cells, especially in the rats transplanted with microencapsulated Schwann cells. The above data show that microencapsulated Schwann cell transplantation inhibits P2X3 receptor expression in L4-5 dorsal root ganglia and neuropathic pain.
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.
