Role of P2X4R in maintenance of trigeminal neuralgia in rats: relationship with p38 MAPK/BDNF signaling pathway / 中华麻醉学杂志

Objective:To evaluate the role of P2X4 receptor (P2X4R) in the maintenance of trigeminal neuralgia and the relationship with p38 mitogen-activated protein kinase (p38 MAPK)/brain-derived neurotrophic factor (BDNF) signaling pathway in rats.Methods:Forty-eight clean-grade healthy adult male Sprague-Dawley rats, weighing 190-230 g, aged 2-3 months, were divided into 4 groups ( n=12 each) using a random number table method: sham operation group (S group), trigeminal neuralgia group (TN group), trigeminal neuralgia+ dimethylsulfoxide (DMSO) group (TN+ DMSO group), and trigeminal neuralgia+ P2X4R specific antagonist 5-BDBD group (TN+ 5-BDBD group). The model was developed by chronic constriction of the infraorbital nerve. The infraorbital nerve was only exposed without ligation in group S. At 3, 7, 10 and 14 days after developing the model, 5 μg/μl 5-BDBD 10 μl was intrathecally injected in TN+ 5-BDBD group, and 2% DMSO 10 μl was intrathecally injected in TN+ DMSO group. The facial mechanical pain withdrawal threshold (MWT) was measured at 1 day before developing the model and 1, 3, 7, 10, 14 and 28 days after developing the model (T 0-6). The rats were sacrificed and the trigeminal ganglia were taken for determination of the expression of P2X4R, p38 MAPK, phosphorylated p38 MAPK (p-p38 MAPK) and BDNF (by Western blot) and contents of tumor necrosis factor (TNF)-α and interleukin (IL)-1β and IL-6 (by enzyme-linked immunosorbent assay). Results:Compared with group S, the MWT was significantly decreased at T 1-6, the expression of P2X4R, p-p38 MAPK and BDNF in trigeminal ganglion was up-regulated, and the contents of TNF-α, IL-1β and IL-6 were increased in TN group ( P<0.05). Compared with TN group, the MWT was significantly increased at T 3-6, and the expression of P2X4R, p-p38 MAPK and BDNF in trigeminal ganglion was down-regulated, and the contents of TNF-α, IL-1β and IL-6 were decreased in TN+ 5-BDBD group ( P<0.05), and no significant change was found in the indexes mentioned above in TN+ DMSO group ( P>0.05). Conclusions:P2X4R is involved in the maintenance of trigeminal neuralgia in rats, which may be related to the activation of p38 MAPK/BDNF signaling pathway and the increase in inflammatory mediator release.

Effect of lappaconitine on neuropathic pain mediated by retrograde transport of P2X3 receptor in dorsal root ganglion neurons of rats with chronic constriction injury of the sciatic nerve / 中华创伤杂志

Objective:To investigate the effect of lappaconitine (LA) on neuropathic pain (NPP) mediated by retrograde transport of purinergic P2X3 receptor (P2X3R) in dorsal root ganglion (DRG) neurons of rats with chronic constriction injury (CCI) of the sciatic nerve.Methods:Seventy-two male healthy SD rats were selected to construct the NPP model following CCI of the sciatic nerve by ligating the right sciatic nerve. according to the random number table method. The rats were divided into CCI group, CCI+LA group and normal control group according to the random number table method, with 24 rats in each group. In normal control group, the right sciatic nerve was exposed without ligation. In CCI+LA group, the rats were given 2 g/L LA (ie, 4 mg/kg intravenously for once a day for one day only) after the same treatment as CCI group. Other two groups were injected with the identical amount of normal saline in the same way. The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were evaluated before injury and at 2, 6, 12 and 24 hours after injury to evaluate the symptoms of neuralgia caused by nerve injury. The proximal and distal nerve fragments were collected in the three groups at 2, 6, 12 and 24 hours after injury. Western blotting was applied to analyze the expression of P2X3R at 2, 6, 12 and 24 hours after injury and the expression of neurotrophic factor (NGF) and tyrosine kinase receptor A (TrkA) at 24 hours after injury to evaluate the effect of LA on P2X3R, NGF and TrkA.Results:There were insignificant differences in MWT and TWL among all groups before injury (all P>0.05). Compared with normal control group, MWT and TWL were significantly decreased in CCI group and CCI+LA group at 2, 6, 12 and 24 hours after injury (all P<0.05 or 0.01). There were insignificant differences in MWT and TWL between CCI group and CCI+LA group at 2 and 6 hours after injury (all P>0.05), while MWT and TWL were significantly higher in CCI+LA group than those in CCI group at 12 and 24 hours after injury (all P<0.05 or 0.01). In the proximal sciatic nerve segment, Western blotting showed similar levels of P2X3R among all groups at 2, 6, 12 and 24 hours after injury (all P>0.05). In the distal sciatic nerve segment, Western blotting showed higher expression of P2X3R in CCI group than that in normal control group at 2, 6, 12, 24 hours after injury (all P<0.01), higher expression of P2X3R in CCI+LA group than that in normal control group at 2, 6 and 12 hours after injury (all P<0.05), similar expression of P2X3R expression between CCI+LA group and normal control group at 24 hours after injury ( P>0.05), similar expression of P2X3R between CCI group and CCI+LA group at 2 and 6 hours after injury (all P>0.05), and lower expression of P2X3R in CCI+LA group than that in CCI group at 12 and 24 hours after injury ( P<0.05 or 0.01). In the proximal and distal nerve fragments, the expression of NGF was lower in normal control group than that in CCI group and CCI+LA group ( P<0.05 or 0.01), but was similar between CCI group and CCI+LA group at 24 hours after injury ( P>0.05). In the proximal and distal nerve fragments, there were insignificant differences in the expression of TrkA among all groups at 24 hours after injury (all P>0.05). Conclusion:Early LA treatment after injury can alleviate mechanical and thermal hyperalgesia in NPP rats, which may be related to the reduction of P2X3R retrograde transport in DRG neuron axonal.

Role of spinal P2Y1R in development of remifentanil-induced hyperalgesia in rats with incisional pain: relationship with function of NR1 and NR2B in spinal cord / 中华麻醉学杂志

Objective:To evaluate the role of spinal P2Y1R in the development of remifentanil-induced hyperalgesia in rats with incisional pain (IP) and the relationship with the function of NR1 and NR2B in spinal cord.Methods:Forty-eight healthy adult male Sprague-Dawley rats, aged 10-12 weeks, weighing 250-280 g, in which intrathecal catheters were successfully placed, were divided into 6 groups ( n=8 each) using a random number table method: control group (group C), P2Y1R antagonist MRS2179 group (group M), remifentanil group (group R), remifentanil plus MRS2179 group (group R+ M), IP plus remifentanil group (group I+ R) and IP plus remifentanil plus MRS2179 group (group I+ R+ M). In group C, normal saline 10 μl was intrathecally injected, and 10 min later normal saline was infused for 60 min via the tail vein at a rate of 0.1 ml·kg -1·min -1.In group M, MRS2179 0.6 nmol/kg was intrathecally injected, and 10 min later normal saline was infused for 60 min via the tail vein at a rate of 0.1 ml·kg -1·min -1.In group R, normal saline 10 μl was intrathecally injected, and 10 min later remifentanil was infused for 60 min via the tail vein at a rate of 1 μg·kg -1·min -1.In group R+ M, MRS2179 0.6 nmol/kg was intrathecally injected, and 10 min later remifentanil was infused for 60 min at a rate of 1 μg·kg -1·min -1 via the tail vein.In group I+ R, normal saline 10 μl was intrathecally injected, 10 min later remifentanil was infused for 60 min via the tail vein at a rate of 1 μg·kg -1·min -1, and IP was established at 10 min after onset of remifentanil infusion.In group I+ R+ M, MRS2179 0.6 nmol/kg was intrathecally injected, 10 min later remifentanil was infused via the tail vein for 60 min at a rate of 1 μg·kg -1·min -1, and IP was established at 10 min after onset of remifentanil infusion.The mechanical paw withdrawal threshold (MWT), thermal paw withdrawal latency (TWL), and the number of paw lifts on the cold plate were measured at 24 h before infusion of remifentanil or normal saline and at 2, 6, 24, and 48 h after the end of infusion.The animals were sacrificed after the last measurement of the pain threshold, L 4-6 segments of the spinal cord were removed for determination of the expression of P2Y1R, phosphorylated NR1 (p-NR1), NR1, phosphorylated NR2B (p-NR2B) and NR2B (by Western blot), for calculation of the ratios of p-NR1/NR1 and p-NR2B/NR2B, and for detection of expression of P2Y1R mRNA, NR1 mRNA and NR2B mRNA (by real-time polymerase chain reaction). Results:Compared with group C, MWT was significantly decreased, TWL was shortened, the number of paw lifts on the cold plate was increased, the expression of P2Y1R protein and mRNA, NR1 protein and mRNA, p-NR1, NR2B protein and mRNA and p-NR2B was up-regulated, and p-NR1/NR1 ratio and p-NR2B/NR2B ratio were increased in group R ( P<0.01). Compared with group R, MWT was significantly increased, TWL was prolonged, the number of paw lifts on the cold plate was decreased, the expression of P2Y1R, p-NR1, NR1 protein and mRNA, p-NR2B, NR2B protein and mRNA was down-regulated, and p-NR1/NR1 ratio and p-NR2B/NR2B ratio were decreased in group R+ M ( P<0.05 or 0.01). Compared with group I+ R, MWT was significantly increased, TWL was prolonged, the number of paw lifts on the cold plate was decreased, the expression of P2Y1R, p-NR1, NR1 protein and mRNA, p-NR2B, NR2B protein and mRNA was down-regulated, and p-NR1/NR1 ratio and p-NR2B/NR2B ratio were decreased in group I+ R+ M ( P<0.01). Conclusion:Spinal P2Y1R can enhance the function of NR1 and NR2B, which may be involved in the development of remifentanil-induced hyperalgesia in rats with IP.

Role of P2X7 receptor in colon cancer progression / 国际肿瘤学杂志

P2X7 receptor is an ion channel receptor with adenosine triphosphate (ATP) as its ligand, which is widely expressed in various immune cells and tissues. Activated P2X7 receptor is involved in a variety of physiological and pathological processes. P2X7 receptor is abnormally expressed in colon cancer, and plays a duel role of cancer-promoting and cancer-suppressing in colon cancer progression. When P2X7 receptor is activated by extracellular ATP, it can effectively inhibit proliferation and induce apoptosis of colon cancer cells through various mechanisms. In addition, P2X7 receptor can also promote the growth, invasion and metastasis of colon cancer. Understanding the activation of P2X7 receptor and its effect mechanism is of great significance for the treatment of colon cancer.

Role of P2X 7 receptor in microglia in medial prefrontal cortex in neuropathic pain in rats: relationship with autophagy / 中华麻醉学杂志

Objective:To evaluate the role of P2X 7 receptor in microglia in the medial prefrontal cortex (mPFC) in neuropathic pain (NP) and the relationship with autophagy in rats. Methods:Sixty-four healthy SPF male Sprague-Dawley rats, aged 6-8 weeks, weighing 200-250 g, were divided into 4 groups ( n=16 each) using a random number table method: sham operation group (S group), NP group, sham operation+ P2X 7 receptor blocking group (SP group), and NP+ P2X 7 receptor blocking group (NP+ P group). The NP model was established by ligation of the sciatic nerve.Fourteen days later a cannula was placed in the mPFC with a brain stereotactic instrument, P2X 7 receptor blocker A-740003 0.5 μg/0.5 μl was injected into bilateral mPFC for 3 consecutive days starting from the 14th day in SP and NP+ P groups, and DMSO 0.5 μl was injected instead of A-740003 in S and NP groups.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured at 3, 7 and 10 days after establishing the model and 14, 15 and 16 days after administration.Then the rats were sacrificed, and the mPFC was removed for determination of the expression of P2X 7 receptor and mRNA and autophagy-related proteins Beclin1 and LC3Ⅱ/Ⅰ (by quantitative real-time polymerase chain reaction or by Western blot) and co-expression of P2X 7R and microglia (by immunofluorescence) and the number of autophagosomes in mPFC (with a transmission electron microscope). Results:Compared with group S, MWT was significantly decreased, and TWL was shortened at 3, 7 and 10 days after establishing the model, the expression of P2X 7 receptor and mRNA, Beclin1 and LC3Ⅱ/Ⅰ was up-regulated at 30 min after administration on 16 days after establishing the model, and the number of cells co-expressing P2X 7 receptor and IBA-1 and the number of autophagosomes were increased in NP and NP+ P groups ( P<0.05), and no significant change was found in the indexes mentioned above in group SP ( P>0.05). Compared with group NP, MWT was significantly increased, and TWL was prolonged at 30 min after administration on 14, 15 and 16 days after establishing the model, the expression of P2X 7 receptor and mRNA, Beclin1 and LC3Ⅱ/Ⅰ was down-regulated, and the number of cells co-expressing P2X 7 receptor and Iba-1 and the number of autophagosome were decreased in group NP+ P ( P<0.05). Conclusion:Up-regulation of P2X 7 receptor expression in microglia in mPFC is involved in the process of NP in rats, which is associated with the promotion of autophagy.

Dexmedetomidine attenuates P2X4 and NLRP3 expression in the spine of rats with diabetic neuropathic pain

Abstract Purpose: To evaluate the effects of Dexmedetomidine (Dex) on spinal pathology and inflammatory factor in a rat model of Diabetic neuropathic pain (DNP). Methods: The rats were divided into 3 groups (eight in each group): normal group (N group), diabetic neuropathic pain model group (DNP group), and DNP model with dexmedetomidine (Dex group). The rat model of diabetes was established with intraperitoneal streptozotocin (STZ) injections. Nerve cell ultrastructure was evaluated with transmission electron microscopy (TEM). The mechanical withdrawal threshold (MWT) and motor nerve conduction velocity (MNCV) tests documented that DNP rat model was characterized by a decreased pain threshold and nerve conduction velocity. Results: Dex restored the phenotype of neurocytes, reduced the extent of demyelination and improved MWT and MNCV of DNP-treated rats (P=0.01, P=0.038, respectively). The expression of three pain-and inflammation-associated factors (P2X4, NLRP3, and IL-IP) was significantly upregulated at the protein level in DNP rats, and this change was reversed by Dex administration (P=0.0022, P=0.0092, P=0.0028, respectively). Conclusion: The P2X4/NLRP3 signaling pathway is implicated in the development and presence of DNP in vivo, and Dex protects from this disorder.

Asociación entre el volumen plaquetario medio y la resistencia a aspirina e inhibidores del receptor p2y12 en pacientes ancianos con síndrome coronario agudo / Association between Mean Platelet Volume and Resistance to Aspirin and P2Y12 Receptor Inhibitors in Elderly Patients with Acute Coronary Syndrome

RESUMEN Introducción: La resistencia a antiagregantes y el volumen plaquetario medio (VPM) son predictores de eventos en el síndrome coronario agudo (SCA). La asociación entre ambos ha sido poco estudiada. Objetivos: Evaluar si existe asociación entre la resistencia a la aspirina (AAS) e inhibidores del receptor P2Y12 (iP2Y12) y el VPM en pacientes mayores de 65 años con SCA. Material y métodos: Se incluyeron pacientes mayores de 65 años con diagnóstico de SCA. Se dividieron en: grupo 1 (resistencia a ambos antiagregantes), grupo 2 (a uno de los antiagregantes) y grupo 3 (a ningún antiagregante). Se midió la agregación plaquetaria entre las 12 y 24 horas poscarga (por light transmission aggregometry). Se consideró resistencia a iP2Y12 a un porcentaje máximo de agregación (PMA) con ADP > 60% y a la AAS a un PMA con ARA > 20%. En el seguimiento se consi-deró el punto final combinado de muerte global y reinternación cardiovascular. Resultados: Se incluyeron 195 pacientes que recibieron AAS e iP2y12 (120 recibieron clopidogrel y 75 ticagrelor); grupo 1 (19%), grupo 2 (34,4%) y grupo 3 (46,6%). El VPM se asoció a la resistencia a ambos antiagregantes (OR 1,02 (IC 95% 1,01-1,05), p = 0,03. A su vez, el VPM y el GRACE fueron predictores independientes del punto combinado (HR 1,03 (IC 95% 1,01-1,07), p = 0,04 y HR 1,02 (IC 95% 1,01-1,04), p = 0,02), respectivamente. Conclusiones: El VPM se asoció a la presencia de resistencia a ambos antiagregantes. En el seguimiento el VPM y el score GRACE fueron predictores del punto combinado.

ABSTRACT Background: Antiplatelet resistance and mean platelet volume (MPV) are event predictors in acute coronary syndrome (ACS). However, the association between both has been poorly studied. Objective: The aim of this study was to evaluate the association between MPV and resistance to aspirin (ASA) and P2Y12 receptor inhibitors (P2Y12i) in elderly patients with ACS. Methods: Patients over 65 years old with diagnosis of ACS were included in the study. They were divided into group 1 (re-sistance to both antiplatelet agents), group 2 (resistance to one antiplatelet agent) and group 3 (no resistance to antiplatelet agents). Platelet aggregation was measured between 12 and 24 hours postload (by light transmission aggregometry). Resis-tance to P2Y12i was considered as maximum percentage of aggregation (MPA) with adenosine diphosphate (ADP) >60% and resistance to ASA as MPA with arachidonic acid (ARA) >20%. The composite endpoint of global death and cardiovascular re-hospitalization was considered during follow-up. Results: One hundred and ninety five patients included in the study received ASA and P2Y12i (120 received clopidogrel and 75 ticagrelor). Nineteen percent of patients belonged to group 1, 34.4% to group 2 and 46.6% to group 3. Mean platelet volume was associated with resistance to both antiplatelet agents [OR 1.02 (95% CI 1.01-1.05), p=0.03], while MPV and the GRACE score were independent predictors of the composite endpoint [HR 1.03 (95% CI 1.01-1.07), p=0.04] and [HR 1.02 (95% CI 1.01-1.04), p=0.02], respectively. Conclusions: Mean platelet volume was associated with the presence of resistance to both antiplatelet agents. During follow-up, MPV and the GRACE score were predictors of the composite endpoint.

Study on the best concentration of miRNA-22 agomir in the treatment of temporal lobe epilepsy by single injection of lateral ventricle / 中国医师杂志

Objective To investigate the optimal initial concentration of microRNA22 agomir in epilepsy model induced by lithium chloride-pilocarpine after single injection of lateral ventricle.Methods 36 rats with acute temporal lobe epilepsy were randomly divided into 6 groups:the control group and the other five groups were the experimental group.All epilepsy rats were selected for right lateral ventricle injection.The control group was given negative control reagent,while the experimental group were given 0.1 mmol/L,2.5 mmol/L,5 mmol/L,10 mmol/L,20 mmol/L different concentrations of miRNA22agomir reagent.6 rats in each group were randomly selected for acute phase experiment after 3 days of administration.The expression of P2X7 in hippocampus of epilepsy rats was determined by Western blot and quantitative real-time polymerase chain reaction (qRT-PCR).Results Compared with control group,the protein and mRNA expression of P2X7 reduced in all of the model group.The protein and mRNA expression level of P2X7 protein in hippocampus of rats injected with 2.5 mmol/L,5 mmol/L and 10 mmol/L in each experimental group were significantly lower than that in the other two groups (P ＜ 0.05).Moreover,the protein and mRNA expression level of P2X7 were the lowest at 2.5 mmol/L injection and 10 mmol/L,and there was no significant difference between the two groups (P ＞ 0.05).Conclusions The optimal onset concentration for unilateral lateral ventricle injection miRNA22 agomir treatment of temporal lobe epilepsy is 2.5 mmol/L.

Correlations of P2Y12 gene polymorphism with clopidogrel resistance and long -term outcome in patients with acute ischemic stroke / 国际脑血管病杂志

Objective To investigate the correlations of P2Y12 gene polymorphisms with clopidogrel resistance and long-term outcome in patients with acute ischemic stroke. Methods From June 2015 to June 2017, consecutive patients with acute ischemic stroke admitted to the Department of Neurology, Nanjing Jiangbei People's Hospital were enrolled. Thromboelastography was used to measure platelet inhibition rate and assess clopidogrel resistance. Polymerase chain reaction was used to assay C34T and G52T polymorphisms of P2Y12 gene. The patients were followed up at 12 months after discharge. The primary outcome was combined outcome of stroke recurrence, myocardial infarction, and death due to cardiocerebrovascular events. Results A total of 214 patients were enrolled, 51 (23.8%) had clopidogrel re-sistance and 29 (13.4%) had major outcome events. One hundred twenty-eight (59.8%) patients were C34T CC genotype and 86 (40.2%) were CT+TT genotype. The proportion of clopidogrel resistance in patients with CT+TT genotype was significantly higher than that with CC genotype ( 76.5% vs.28.8%;χ2=25.672, P=0.001). There were 131 patients (61.2%) with G52T GG genotype and 83 (38.8%) with GT+TT genotype. There was no significant difference in the proportion of clopidogrel resistance between the GT+TT genotype and the GG genotype (43.1% vs.37.4%; χ2=0.534, P=0.465). Multiple logistic regression analysis indicated that age (odds ratio [OR] 1.064, 95%confidence interval [CI] 1.009-1.115;P=0.021), diabetes ( OR 3.773, 95%CI 1.672-8.475; P=0.004), and C34T CT+TT genotype ( OR 9.087, 95%CI 4.416-22.665; P=0.002) were the independent risk factors fot clopidogrel resistance. Cox proportional hazards model analysis showed that age (Hazard ratio [HR] 1.058, 95%CI 1.001-1.121; P=0.049), hypertension ( HR 3.105, 95%CI 1.149-9.523; P=0.028), homocysteine ( HR 1.101, 95%CI 1.020-1.190; P=0.014), and C34T CT+TT genotype ( HR 2.588, 95%CI 1.121-5.967; P=0.026) were independent risk factors for the composite outcome. Conclusion C34T polymorphism of P2Y12 gene in patients with acute ischemic stroke may be a risk factor for clopidogrel resistance and is independently associated with the risk of long-term recurrence of vascular events.

Role of P2X7 receptor in ventrolateral periaqueductal gray in tramadol-induced reduction of neuropathic pain in rats / 中华麻醉学杂志

Objective To evaluate the role of P2X7 receptor in the ventrolateral periaqueductal gray (vlPAG) in tramadol-induced reduction of neuropathic pain (NP) in rats.Methods Fifty-four male clean-grade healthy Sprague-Dawley rats,aged 7 days,weighing 190-230 g,were studied.NP was induced by chronic constrictive injury (CCI) to sciatic nerve.Experiment Ⅰ Thirty-six rats were divided into 3 groups (n =12 each) using a random number table method:sham operation group (group S),group NP1 and NP plus tramadol group (group NP1 +T).Tramadol 15 mg/kg was intraperitoneally injected once a day from day 7 to day 14 after CCI in group NP1+T.The mechanical and thermal pain thresholds of the nerve-injured hindlimb were measured before CCI and on 1,5,7,10,12 and 14 days after CCI.Rats were sacrificed after measurement of pain threshold on day 14 after CCI,and the expression of P2X7 receptor in vlPAG was detected by immunohistochemistry and Western blot assay.Experiment Ⅱ Eighteen rats were divided into 3 groups (n =6 each) using a random number table method:group NP2,NP plus tramadol group (group NP2+T) and NP plus tramadol plus a specific P2X7 receptor antagonist A-438079 group (group NP2+T+A).In NP2+T+A group,a catheter was implanted in vlPAG,and the NP model was established on 5th day after successful catheterization.Tramadol 15 mg/kg was intraperitoneally injected once a day from day 7 to day 14 after CCI in group NP2+T.In group NP2+T+A,tramadol 15 mg/kg was intraperitoneally injected once a day from day 7 to day 14 after CCI,followed by a microinjection of A-438079 100 pmol (0.3 μl) via vlPAG before giving tramadol on day 14.The mechanical and thermal pain thresholds were measured at the end of the last tramadol administration and within 1 h after the end of the last tramadol administration.Results Experiment Ⅰ Compared with group S,the mechanical and thermal pain thresholds were significantly decreased at each time point after CCI,the number of P2X7 receptor positive cells was increased,and the expression of P2X7 receptor was up-regulated in the other two groups (P＜0.01).Compared with group NP1,the mechanical and thermal pain thresholds were significantly increased at days 7-14 after CCI,the number of P2X7 receptor positive cells was increased,and the expression of P2X7 receptor was up-regulated in group NP1 +T (P＜0.01).Experiment Ⅱ Compared with group NP2,the mechanical and thermal pain threshold were significantly increased at each time point after CCI in NP2+T and NP2 +T+A groups (P＜0.01).Compared with group NP2 +T,the mechanical and thermal pain thresholds were significantly decreased at each time point after CCI in group NP2+T+A (P＜ 0.01).Conclusion The mechanism by which tramadol mitigates NP is partially related to enhanced function of P2X7 receptors in vlPAG of rats.

Expression of P2X7 receptor in RGC-5 cell line and selection of an effective siRNA sequence down-regulating P2X7 receptor / 中国医师杂志

Objective This study aims to investigate the gene expression of P2X7 receptor in retinal ganglion cell line (RGC-5),and to design and select the small interfering RNA (siRNA) which can specifically and effectively downregulate P2X7 receptor expression.Methods The mRNA and protein expressions of P2X7 receptor in RGC-5 cells were examined by real-time polymerase chain reaction (qRT-PCR),Western blot and Immunofluorescence,and compared with those of mouse retina and other tissues.Three P2X7 receptor-specific double stranded siRNAs (P2X7-siRNA-1-3) were designed and delivered into RGC-5 cells by riboFECTTM CP.60 hours after transfection,the expression level of P2X7 receptor was analyzed by qRT-PCR,Western blot and Immunofluorescence.Results The expression of P2X7 receptor was detected in both RGC-5 cell line and mouse retina,and the receptor was mainly expressed in the nucleus and cytoplasm of RGC-5 cells.P2X7-siRNA-3 can effectively down-regulate the mRNA and protein expression of P2X7 at the same time.Conclusions RGC-5 cell line can serve as a good model for studying the biological function of P2X7 receptor in retinal ganglion cells in vitro.We have managed to design and synthesize the siRNA pair that specifically and effectively lowering P2X7 receptor expression.The current study has laid the foundation for future investigations on treating glaucomatous retinopathy by downregulation of P2X7 receptor.

Correlations of P2Y1 and ITGB3 polymorphisms with aspirin resistance in patients with large artery atherosclerotic stroke / 国际脑血管病杂志

Objective To investigate the correlations of P2Y1 and ITGB3 single nucleotide polymorphisms (SNP) with aspirin resistance (AR) in patients with large atherosclerotic stroke (LAA) in a Chinese Han population.Methods Patients with first-ever LAA from Anhui stroke registration system were enrolled.Thrombus elasticity diagram was used to detect the platelet function.TaqMan technology was used to detect the P2Y1 and ITGB3 genotypes.Results A total of 206 patients with LAA were enrolled.Thirty-one patients (15.0％) had AR and 175 (85.0％) were aspirin sensitive (AS).The frequency of P2Y1 rs701265 G allele in the AR group was significantly higher than that in the AS group (43.5％ vs.26.9％;x2 =7.074,P=0.008).The frequency of P2Y1 rs701265 AA genotype in the AR group was significantly lower than that in the AS group (32.3％ vs.53.7％;x2 =4.850,P=0.028).There were no significant significances in the frequencies of P2Y1 rs1065776 and ITGB3 rs5918 alleles and genotypes between the AR group and the AS group.Multivariate logistic regression analysis showed that P2Y1 rs701265 G allele was an independent risk factor for AR in patients with LAA (odds ratio 2.186,95％ confidence interval 1.190-4.016;P=0.012).Conclusion The P2Y1 rs701265 polymorphism is associated with AR in Chinese Han patients with LAA,while the P2Y1 rs1065776 and ITGB3 rs5918 polymorphisms are not.

Effect of dexmedetomidine on spinal P2X4/NLRP3 pathway in a rat model of diabetic neuropathic pain / 中华麻醉学杂志

Objective To evaluate the effect of dexmedetomidine on spinal purinergic receptor 2X-4 (P2X4)/nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) pathway in a rat model of diabetic neuropathic pain (DNP).Methods Twenty-four pathogenfree adult male Sprague-Dawley rats,weighing 200-220 g,aged 8 weeks,were allocated into 3 groups (n =8 each) using a random number table:control group (C group),DNP group and DNP plus dexmedetomidine group (DNP+D group).Diabetes mellitus was induced by intraperitoneal 1％ streptozotocin 60 mg/kg and confirmed by blood glucose ≥ 16.7 mmol/L 3 days later.In group DNP+D,dexmedetomidine 50 μg/kg was intraperitoneally injected once a day for 6 consecutive weeks starting from 3 days after the model was successfully established.The mechanical paw withdrawal threshold (MWT) and sciatic nerve conduction velocity (SNCV) were measured at 2,4 and 6 weeks after injection of dexmedetomidine.The rats were sacrificed at 6 weeks after injection of dexmedetomidine,and the L4-6 segments of the spinal cord were removed for examination of the pathological changes (with a light microscope) and for determination of P2X4,NLRP3 and interleukin-lbeta (IL-1β3) expression (by Western blot).The sural nerve was obtained for examination of the ultrastructure by electron microscopy.Results Compared with group C,the MWT was significantly decreased at 2,4 and 6 weeks after injection of dexmedetomidine,the SNCV was decreased at 6 weeks after injection of dexmedetomidine,the expression of P2X4,NLRP3 and IL-1β in the spinal cord was up-regulated (P＜0.05),and the pathological changes of the spinal cord and sural nerve were marked in DNP and DNP+D groups.Compared with group DNP,the MWT was significantly increased at 2,4 and 6 weeks after injection of dexmedetomidine,the SNCV was increased at 6 weeks after injection of dexmedetomidine,the expression of P2X4,NLRP3 and IL-1β in the spinal cord was down-regulated (P＜0.05),and the pathological changes of the spinal cord and sural nerve were significantly attenuated in group DNP+D.Conclusion The mechanism by which dexmedetomidine mitigates DNP is probably related to inhibition of P2X4/NLRP3 pathway in rats.

Effects of lappaconitine on pain and inflammatory response of severely burned rats and the mechanism / 中华烧伤杂志

Objective@#To explore the effects of lappaconitine (LA) on pain and inflammatory response of severely burned rats and the mechanism.@*Methods@#Forty SD rats were divided into healthy+ normal saline group, sham injury+ normal saline group, pure burn group, burn+ LA group, and healthy+ LA group according to the random number table (the same dividing method below), with 8 rats in each group. Rats in pure burn and burn+ LA groups were inflicted with about 32% total body surface area deep partial-thickness scald (hereinafter referred to as burn) on the back and right hind. Rats in sham injury+ normal saline group were sham injured. Rats in burn+ LA group were intraperitoneally injected with 1 g/L LA solution in the dosage of 4 mL/kg at 2.0 h before injury and post injury hour (PIH) 0 (immediately), 24.0, 48.0, and 72.0. Rats in healthy+ LA group were intraperitoneally injected with LA solution in the same dose at the same time points as above, and rats in healthy+ normal saline and sham injury+ normal saline groups were intraperitoneally injected with normal saline in the dose of 4 mL/kg at the same time points as above. At 1.5 h before injury and PIH 12.5, 24.5, 36.5, 48.5, and 72.5, the paw withdrawal mechanical threshold (PWMT) of injured rats was detected, and their pain behaviors were observed. The same observation and detection were conducted in rats without injury in the two groups at the same time points as above. Another 32 SD rats were divided into normal saline group, trinitrophenyl (TNP)-ATP group, minocyline group, pyridoxal-phosphate-6-azophenyl-2', 4'-disulfonic acid (PPADS) group, with 8 rats in each group, and all the rats were inflicted with the same burn injury as above. At PIH 48.0, rats in normal saline group were intrathecally injected with 10 μL normal saline; rats in TNP-ATP group were intrathecally injected with 10 μL TNP-ATP in the concentration of 30 nmol/μL; rats in minocyline group were intrathecally injected with 10 μL minocyline in the concentration of 5 g/L; rats in PPADS group were intrathecally injected with 10 μL PPADS in the concentration of 10 nmol/μL. The PWMT of rats was detected at 0.5 h before injection and 0.5 h after. At PIH 72.5, the tissue in the dorsal horn of spinal cord of rats in sham injury+ normal saline, pure burn, and burn+ LA groups was harvested to observe the co-expression of P2X4 receptor and OX42 receptor with immunofluorescent staining and to observe the expression of P2X4 receptor and count the positive cells with immunohistochemical staining. The venous blood was harvested for determination of serum content of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) with enzyme-linked immunosorbent assay. The same observation and determination were conducted in rats without injury in the two groups at the same time point as above. Data were processed with one-way analysis of variance, analysis of variance for repeated measurement, SNK test, paired t test, and Bonferroni correction.@*Results@#(1) There were no abnormal activity in rats of healthy+ normal saline, sham injury+ normal saline, healthy+ LA groups at all time points. Until PIH 72.5, rats in pure burn group were in poor mental state; red and swollen manifestation and blister were observed in burn wounds on the back and right hind; imbalance in gait, lick, bite, and scratch were observed occasionally. Fewer behaviors such as lick, bite, and limp were observed in rats in burn+ LA group than in pure burn group, and the red and swollen manifestation in wounds of rats in burn+ LA group dissipated faster than that in pure burn group. (2) At 1.5 h before injury, there were no significant differences in the PWMT values of rats in healthy+ normal saline, sham injury+ normal saline, pure burn, burn+ LA, and healthy+ LA groups (F=0.106, P>0.05). PWMT values of rats in pure burn group were significantly lower than those in the other 4 groups at all post injury time points (with P values below 0.05). PWMT values of rats in burn+ LA group were significantly lower than those in healthy+ normal saline, sham injury+ normal saline, and healthy+ LA groups at all post injury time points (with P values below 0.05). (3) At 0.5 h before injection, PWMT values of rats in normal saline, TNP-ATP, PPADS, and minocyline groups were close, respectively 15.3±0.8, 15.1±1.0, 15.3±0.9, and 15.6±1.1 (F=0.343, P>0.05). At 0.5 h after injection, PWMT values of rats in normal saline group and PPADS group were respectively 15.2±1.2 and 14.8±1.0, which were significantly lower than 20.8±1.4 and 26.3±1.0 in TNP-ATP group and minocyline group respectively (with P values below 0.05). PWMT values of rats in normal saline and PPADS groups were similar before and after injection (with t values respectively 0.073 and -0.772, P values above 0.05), while those of rats in TNP-ATP and minocyline groups were higher after injection than before injection (with t values respectively -10.180 and -20.813, P values below 0.01). (4) At PIH 72.5, co-expression of P2X4 receptor and OX42 receptor was observed in a few microglias of rats in healthy+ normal saline, sham injury+ normal saline, and healthy+ LA groups, while co-expression of P2X4 receptor and OX42 receptor was observed in a large number of microglias of rats in pure burn and burn+ LA groups. At PIH 72.5, more P2X4 receptor positive cells were observed in rats in pure burn group than in the other 4 groups (with P values below 0.05), and more P2X4 receptor positive cells were observed in rats in burn+ LA group than in healthy+ normal saline, sham injury+ normal saline, and healthy+ LA groups (with P values below 0.05). (5) At PIH 72.5, the serum content of TNF-α and IL-1β of rats in pure burn group was significantly higher than that in the other 4 groups (with P values below 0.001). The serum content of TNF-α and IL-1β of rats in burn+ LA group was significantly lower than that in healthy+ normal saline, sham injury+ normal saline, and healthy+ LA groups (with P values below 0.001).@*Conclusions@#LA has significant analgesic effects on severely burned rats, and it can ameliorate the excessive inflammational situation. The mechanism may be related to its inhibition of expression of P2X4 receptor in microglias in the dorsal horn of spinal cord and reduction in the release of inflammatory factors TNF-α and IL-1β.

Inhibidores del receptor plaquetario P2Y12. Parte 1 de 2: escenario de acción, farmacología, aplicación clínica y limitaciones de su uso / Platelet P2Y12 receptor inhibitors. Part 1 of 2: Scenario of action, pharmacology, clinical application, and limitations of its use

Resumen: las enfermedades cardiovasculares, incluidas las afecciones del corazón, del cerebro y de los vasos sanguíneos en general, representan la primera causa de muerte a nivel mundial, con diecisiete millones y medio de muertes cada año. La prevención primaria y secundaria de las enfermedades aterotrombóticas, como el infarto agudo de miocardio, el accidente cerebrovascular y las enfermedades trombóticas, además de las medidas generales para el control de los factores de riesgo tales como la obesidad, el sedentarismo, el tabaquismo, la hipertensión arterial y la diabetes, se han centrado en el control de la agregación plaquetaria. El antiagregante plaquetario por excelencia o universal, sobre todo en la prevención primaria, es la aspirina y la terapia dual con la combinación de aspirina y un inhibidor del receptor plaquetario P2Y12, principalmente el clopidogrel, es usada en la prevención secundaria y en los casos de resistencia a la aspirina. En el momento, se dispone para uso clínico de seis inhibidores del receptor plaquetario P2Y12: la ticlopidina, el clopidogrel, el prasugrel, el ticagrelor, el cangrelor y el elinogrel. En este primer módulo, de dos que serán presentados, se abordará el uso de los inhibidores del receptor plaquetario P2Y12 en la práctica del día a día en la prevención primaria y secundaria de las enfermedades aterotrombóticas, enfocado en el análisis del papel de las plaquetas en la fisiopatología de la enfermedad aterotrombótica y la descripción de los seis inhibidores del receptor plaquetario P2Y12 disponibles ahora y en el futuro. En un segundo módulo se hará una aproximación al concepto de la resistencia a los inhibidores del receptor plaquetario P2Y12, su diagnóstico desde el punto de vista del laboratorio y las diferentes alternativas de manejo cuando se presenta resistencia a uno de estos medicamentos. (AU)

Abstract: Cardiovascular diseases, including in general heart diseases, brain, and blood vessels are the leading cause of death worldwide with 17.000.000 of deaths each year. Primary and secondary prevention of atherothrombotic diseases, as acute myocardial infarction, stroke, and thrombotic disorders, besides to the general measures for risk factors control such as obesity, sedentary lifestyle, smoke, high blood pressure, and diabetes, have focused on platelet aggregation control. The antiplatelet agent par excellence or universal, especially in primary prevention, is aspirin, and dual therapy with the combination of aspirin and a platelet receptor inhibitor P2Y12, with clopidogrel as the most used, for secondary prevention and in cases of aspirin resistance. Currently, six P2Y12 platelet receptor inhibitors are available for clinical use: ticlopidine, clopidogrel, prasugrel, ticagrelor, cangrelor, and elinogrel. In this first of two modules, the use of P2Y12 receptor inhibitors in daily practice in the primary and secondary prevention of atherothrombotic diseases will be addressed focused on the analysis of the platelets role in atherothrombotic disease pathophysiology and description of the six P2Y12 platelet receptor inhibitors available now and in the future. In a second module, we will approach the concept of resistance to platelet P2Y12 receptor inhibitors, its diagnosis from the laboratory point of view and the different management alternatives when resistance to one of these drugs is present. (AU)

Comparison of the Infarct Size between the Loading of Ticagrelor and Clopidogrel in Patients with Acute Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND AND OBJECTIVES: Ticagrelor is considered a potent antiplatelet agent compared to clopidogrel. However, there are no studies regarding the effect of ticagrelor loading on infarct size in patients with ST-segment elevation myocardial infarction (STEMI) in a primary percutaneous coronary intervention (PCI) setting. SUBJECTS AND METHODS: In this single-center, randomized, open-label study, 188 patients who underwent primary PCI for STEMI were enrolled (92 patients in the clopidogrel group and 96 in the ticagrelor group) and compared the infarct size by technetium-99m (Tc-99m) tetrofosmin single-photon emission computed tomography (SPECT) and serial cardiac biomarker levels between the groups. SPECT was performed at a median of 2 days after PCI. RESULTS: Baseline clinical and procedural characteristics were similar between the groups. Infarct size on SPECT, was similar between the 2 groups (28.1%±34.5% vs. 32.8%±29.2%; p=0.169). At all time-points after PCI (8, 24, and 48 hours), the peak levels of creatine kinase-myocardial band (CK-MB) and troponin T were lower in the clopidogrel group. The clopidogrel group showed lower cumulative troponin T levels than the ticagrelor group (12.59±10.66 vs. 17.67±19.51 ng/mL; p=0.029). CONCLUSION: Ticagrelor loading before primary PCI was not associated with reduced myocardial infarct size during the first 48 hours, compared to clopidogrel loading.

P2X7 receptor and relationship with the death of retinal neurons / 中华眼底病杂志

Retinal neuronal cells are crucial in the formation of vision.Injury or death of these cells may lead to irreversible damage to visual function due to their low regenerative capacity.The P2X7 receptor is a trimeric adenosine triphosphate (ATP)-gated cation channel.Recent studies have shown that P2X7 receptor plays a role in retinal neuronal death.In a series of animal models,when exposed to conditions of hypoxia or ischemia,elevated ocular pressure,trauma and exogenous agonists,P2X7 receptor activated by extracellular ATP can cause death of retinal neuronal cells such as retinal ganglion cells and photoreceptor cells through direct or indirect pathways.Blocking the expression and function of P2X7 receptor by its specific antagonist and gene knocking-out,the loss of retinal neuronal cells is significantly attenuated.P2X7 receptor may become a potential novel neuroprotective target for diseases related to the loss of retinal neurons.

Effects of hyperbaric oxygen post-conditioning on expression of P2X4 receptor in spinal dorsal horn and hippocampus of rats with neuropathic pain / 中华麻醉学杂志

Objective To evaluate the effects of hyperbaric oxygen post-conditioning on the expression of P2X4 receptors in the spinal dorsal horn and hippocampus of rats with neuropathic pain (NP).Methods Seventytwo male Sprague-Dawley rats,aged 8-10 weeks,weighing 300-350 g,were randomly divided into 3 groups (n =24 each) using a random number table:sham operation group (group S),NP group and hyperbaric oxygen postconditioning group (group H).NP was induced by chronic constrictive injury.The rats in group H underwent hyperbaric oxygen treatment once a day for 7 consecutive days starting from 1 day after NP was successfully induced.After the rats were placed in the hyperbaric oxygen chamber,the pressure was increased at a rate of 10 kPa/min until the hyperbaric oxygen was at 2.0 atmosphere absolute,and maintained at this level for 60 min,and then the pressure was decreased at a rate of 10 kPa/min until the normal pressure was reached.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured at 1 day before NP was induced and 1,3,7 and 14 days after NP was induced.After the end of measurement,6 rats were randomly chosen from each group and then sacrificed and the L4-6 segments of the spinal cord and hippocampal tissues were removed for determination of the expression of P2X4 receptors (by immunohistochemistry).Results Compared with group S,the MWT was significantly decreased,TWL was shortened,and P2X4 receptor expression in the spinal dorsal horn and hippocampus was up-regulated in NP and H groups.Compared with group NP,the MWT was significantly increased and TWL was prolonged,and P2X4 receptor expression in the spinal dorsal horn and hippocampus was down-regulated in group H.Conclusion Hyperbaric oxygen post-conditioning mitigates NP by down-regulating the expression of P2X4 receptors in the spinal dorsal horn and hippocampus of rats.

P2X7 Receptor Expression in Coexistence of Papillary Thyroid Carcinoma with Hashimoto's Thyroiditis

BACKGROUND: This study was aimed at investigating the relation of P2X7 receptor (P2X7R) expression with the clinicopathological features of papillary thyroid carcinoma (PTC) coexisting with Hashimoto's thyroiditis (HT). METHODS: We examined 170 patients (84, PTC with HT; 86, PTC without HT). P2X7R expression was examined by immunohistochemical methods. The staining intensity and patterns were evaluated and scored using a semi-quantitative method. RESULTS: The PTC with HT group was more likely to contain women and had less extrathyroid extension, lymph node (LN) metastasis, lymphovascular invasion, and recurrence than the PTC without HT group. Patients positive for P2X7R had significantly higher frequencies of lymphovascular invasion, extrathyroid extension, LN metastasis, and absence of HT. As shown by multivariate analysis, the expression of P2X7R was significantly higher if HT was absent and extrathyroid extension was present. In the PTC with HT group, the expression of P2X7R was significantly higher in patients with tumor multifocality, lymphovascular invasion, and extrathyroid extension. In the PTC without HT group, the expression of P2X7R was significantly higher in women and those having tumor multifocality. CONCLUSIONS: Coexistence of PTC with HT is associated with good prognostic factors, and P2X7R expression in PTC was correlated with poor prognostic factors and the absence of HT.

P2X7 receptor mediates activation of microglial cells in prostate of chemically irritated rats

Purpose Evidence shows that adenosine triphosphate (ATP) is involved in the transmission of multiple chronic pain via P2X7 receptor. This study was to investigate the P2X7 and microglial cells in the chronic prostatitis pain. Materials and Methods Rats were divided into control group and chronic prostatitis group (n = 24 per group). A chronic prostatitis animal model was established by injecting complete Freund's adjuvant (CFA) to the prostate of rats, and the thermal withdrawal latency (TWL) was detected on days 0, 4, 12 and 24 (n = 6 at each time point in each group). Animals were sacrificed and the pathological examination of the prostate, detection of mRNA expression of P2X7 and ionized calcium binding adaptor molecule 1 (IBA-1) and measurement of content of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the dorsal horn of L5-S2 spinal cord were performed on days 0, 4, 12 and 24. In addition, the content of TNF-α and IL-1β in the dorsal horn of L5-S2 spinal cord was measured after intrathecal injection of inhibitors of microglial cells and/or P2X7 for 5 days. Results The chronic prostatitis was confirmed by pathological examination. The expression of P2X7 and IBA-1 and the content of TNF-α and IL-1β in rats with chronic prostatitis were significantly higher than those in the control group. On day 4, the expressions of pro-inflammatory cytokines became to increase, reaching a maximal level on day 12 and started to reduce on day 24, but remained higher than that in the control group. Following suppression of microglial cells and P2X7 receptor, the secretion of TNF-α and IL-1β was markedly reduced. Conclusion In chronic prostatitis pain, the microglial cells and P2X7 receptor are activated resulting in the increased expression of TNF-α and IL-1β in the L5-S2 spinal cord, which might attribute to the maintenance and intensification of pain in chronic prostatitis. .