TET2重塑CXCR4 DNA甲基化对急性心肌梗死小鼠心肌组织自噬、炎症反应及凋亡的影响

目的:探究急性心肌梗死(AMI)过程中内皮细胞tet甲基胞嘧啶双加氧酶2(TET2)对趋化因子受体4(CXCR4)DNA甲基化的影响以及对AMI小鼠心肌组织自噬、炎症反应及组织细胞凋亡的影响机制,为临床探究AMI发展的分子机制提供理论依据。方法:8周龄雄性C57/BL6小鼠50只,制备AMI模型,尾部注射TET2、CXCR4过表达质粒;蛋白免疫印迹(Western Blot)法检测心肌组织TET2、CXCR4、微管相关蛋白3(LC3)、P62、B细胞淋巴瘤/白血病-2基因(Bcl-2)关联X蛋白(Bax)、半胱氨酸蛋白酶3(Caspase-3)、Bcl-2表达;甲基化检测CXCR4 DNA甲基化水平;酶联免疫吸附法(ELISA)检测心肌组织内炎性因子白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)水平;原位末端转移酶标记技术(TUNEL)检测各组心肌组织细胞凋亡指数。结果:与假手术组比较,模型组心肌组织内TET2、CXCR4均表达上调,TET2、CXCR4均在心肌组织内过表达,TET2过表达促进CXCR4表达,差异有统计学意义(P<0.05);与模型组比较,TET2 mimic组CXCR4启动子区域DNA甲基化程度降低,CXCR4蛋白表达升高,差异有统计学意义(P<0.05);与假手术组比较,模型组小鼠心肌组织自噬蛋白LC3、抑制细胞凋亡蛋白Bcl-2表达下调,炎性因子IL-6、TNF-α、IL-1β水平、自噬蛋白P62、促细胞凋亡蛋白Bax、cleaved Caspase-3表达上调,差异有统计学意义(P<0.05);TET2、CXCR4过表达进一步下调LC3、Bcl-2蛋白表达,上调炎性因子IL-6、TNF-α、IL-1β水平,P62、Bax、cleaved Caspase-3蛋白表达;TET2、CXCR4二者联合体现出最低LC3、Bcl-2蛋白表达,最高炎性因子IL-6、TNF-α、IL-1β水平以及P62、Bax、cleaved Caspase-3蛋白表达,差异有统计学意义(P<0.05)。结论:AMI发展中,TET2通过降低CXCR4 DNA甲基化,促进CXCR4基因表达,进而抑制AMI小鼠心肌组织自噬,上调炎症反应及细胞凋亡程度,促进疾病发展。

PXR基因单核苷酸多态性与2型糖尿病患病风险的关系

目的探讨孕烷X受体(PXR)基因单核苷酸多态性(SNP)与2型糖尿病(T2DM)患病风险的关系。方法选择T2DM患者285例(观察组)、同期体检健康的志愿者230例(对照组),采集所有研究对象空腹外周静脉血,提取基因组DNA,然后对PXR基因rs1523127、rs3814055、rs6785049位点进行测序和基因分型;采用ELISA法检测血清PXR、葡萄糖转运体2(GLUT2)、葡萄糖激酶(GCK)。比较两组PXR基因rs1523127、rs3814055、rs6785049位点基因型及等位基因频率,以及血清PXR、GLUT2、GCK水平。分析PXR基因SNP与T2DM患病风险的关系。结果经Hardy-Weinberg遗传平衡检验,两组PXR基因不同位点基因型、等位基因频率均符合遗传平衡定律。两组PXR基因rs1523127、rs6785049位点基因型及等位基因频率比较差异均无统计学意义(P均>0.05)。观察组PXR基因rs3814055位点CT/TT基因型及T等位基因频率均高于对照组(P均<0.05),携带CT、TT基因型者罹患T2DM的优势比(OR)分别为携带CC基因型者的1.591、2.398倍,携带T等位基因者罹患T2DM的OR为携带C等位基因者的1.638倍。观察组血清PXR水平高于对照组,血清GLUT2、GCK水平低于对照组(P均<0.05)。T2DM患者PXR基因rs3814055位点CT/TT基因型者血清PXR水平高于CC基因型者,血清GLUT2、GCK水平低于CC基因型者(P均<0.05)。结论PXR基因rs3814055位点C等位基因突变为T等位基因能够增加其转录活性,抑制血清GLUT2、GCK水平,使其糖耐量受损,进而增加T2DM的患病风险。

C-X-C趋化因子受体4增强Toll样受体2在肺炎衣原体感染促进动脉粥样硬化病变形成中的作用

[目的]探究C-X-C趋化因子受体4(CXCR4)在肺炎衣原体(C.pn)感染促进动脉粥样硬化(As)病变形成中的作用。[方法]以高脂饮食为基础,建立C.pn感染诱导ApoE^(-/-)、ApoE^(-/-)+Toll样受体2(TLR2)^(-/-)、ApoE^(-/-)+TLR2^(-/-)+AMD3100小鼠As模型,ELISA检测ApoE^(-/-)小鼠血清C.pn IgG、IgM抗体水平,PCR检测肺组织C.pn特异性DNA,油红O染色和HE染色观察主动脉及主动脉根部脂质沉积和As病变面积,比色法测定血清总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDLC)和高密度脂蛋白胆固醇(HDLC)水平,ELISA检测血清白细胞介素1β(IL-1β)和白细胞介素6(IL-6)含量。[结果]ApoE^(-/-)小鼠C.pn感染模型成功建立。与对照组相比,C.pn感染后ApoE^(-/-)小鼠主动脉及主动脉根部脂质沉积量增加89.08%和71.83%,As病变面积增加34.12%(均P<0.05);与C.pn感染组相比,TLR2^(-/-)+C.pn感染组主动脉及主动脉根部脂质沉积量减少46.16%和75.73%,As病变面积减少63.37%(均P<0.05);与TLR2^(-/-)+C.pn感染组相比,TLR2^(-/-)+AMD3100+C.pn感染组主动脉及主动脉根部脂质沉积量减少26.19%和56.94%,As病变面积则减少22.24%(均P<0.05)。与对照组相比,C.pn感染后血清TC、TG和LDLC水平分别升高0.62倍、1.43倍和1.34倍,血清IL-1β和IL-6含量分别增加4.10倍和6.00倍(均P<0.05);与C.pn感染组相比,TLR2^(-/-)+C.pn感染组血清TC、TG和LDLC水平分别降低56.96%、50.41%和66.64%,血清IL-1β和IL-6含量分别减少66.72%和69.54%(均P<0.05);与TLR2^(-/-)+C.pn感染组相比,TLR2^(-/-)+AMD3100+C.pn感染组血清TC、TG和LDLC水平分别降低52.18%、58.56%和60.61%,血清IL-1β和IL-6含量分别减少28.84%和43.18%(均P<0.05)。[结论]CXCR4可增强TLR2在升高血脂水平及炎症因子含量中的作用,进而参与C.pn感染诱导的As病变形成。

Study of the roles of caspase-3 and nuclear factor kappa B in myenteric neurons in a P2X7 receptor knockout mouse model of ulcerative colitis

BACKGROUND The literature indicates that the enteric nervous system is affected in inflammatory bowel diseases(IBDs)and that the P2X7 receptor triggers neuronal death.However,the mechanism by which enteric neurons are lost in IBDs is unknown.AIM To study the role of the caspase-3 and nuclear factor kappa B(NF-κB)pathways in myenteric neurons in a P2X7 receptor knockout(KO)mouse model of IBDs.METHODS Forty male wild-type(WT)C57BL/6 and P2X7 receptor KO mice were euthanized 24 h or 4 d after colitis induction by 2,4,6-trinitrobenzene sulfonic acid(colitis group).Mice in the sham groups were injected with vehicle.The mice were divided into eight groups(n=5):The WT sham 24 h and 4 d groups,the WT colitis 24 h and 4 d groups,the KO sham 24 h and 4 d groups,and the KO colitis 24 h and 4 d groups.The disease activity index(DAI)was analyzed,the distal colon was collected for immunohistochemistry analyses,and immunofluorescence was performed to identify neurons immunoreactive(ir)for calretinin,P2X7 receptor,cleaved caspase-3,total caspase-3,phospho-NF-κB,and total NF-κB.We analyzed the number of calretinin-ir and P2X7 receptor-ir neurons per ganglion,the neuronal profile area(μm^(2)),and corrected total cell fluorescence(CTCF).RESULTS Cells double labeled for calretinin and P2X7 receptor,cleaved caspase-3,total caspase-3,phospho-NF-κB,or total NF-κB were observed in the WT colitis 24 h and 4 d groups.The number of calretinin-ir neurons per ganglion was decreased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(2.10±0.13 vs 3.33±0.17,P<0.001;2.92±0.12 vs 3.70±0.11,P<0.05),but was not significantly different between the KO groups.The calretinin-ir neuronal profile area was increased in the WT colitis 24 h group compared to the WT sham 24 h group(312.60±7.85 vs 278.41±6.65,P<0.05),and the nuclear profile area was decreased in the WT colitis 4 d group compared to the WT sham 4 d group(104.63±2.49 vs 117.41±1.14,P<0.01).The number of P2X7 receptor-ir neurons per ganglion was decreased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(19.49±0.35 vs 22.21±0.18,P<0.001;20.35±0.14 vs 22.75±0.51,P<0.001),and no P2X7 receptor-ir neurons were observed in the KO groups.Myenteric neurons showed ultrastructural changes in the WT colitis 24 h and 4 d groups and in the KO colitis 24 h group.The cleaved caspase-3 CTCF was increased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(485949±14140 vs 371371±16426,P<0.001;480381±11336 vs 378365±4053,P<0.001),but was not significantly different between the KO groups.The total caspase-3 CTCF,phospho-NF-κB CTCF,and total NF-κB CTCF were not significantly different among the groups.The DAI was recovered in the KO groups.Furthermore,we demonstrated that the absence of the P2X7 receptor attenuated inflammatory infiltration,tissue damage,collagen deposition,and the decrease in the number of goblet cells in the distal colon.CONCLUSION Ulcerative colitis affects myenteric neurons in WT mice but has a weaker effect in P2X7 receptor KO mice,and neuronal death may be associated with P2X7 receptor-mediated caspase-3 activation.The P2X7 receptor can be a therapeutic target for IBDs.

应用BP人工神经网络探讨PPAR-γ和RXR-α基因多态性与汉族人群2型糖尿病遗传易感性的关系

目的:探讨BP人工神经网络(BPANN)在研究过氧化物酶体增殖物激活受体γ(PPAR-γ)和视黄醛α受体(RXR-α)基因单核苷酸多态性(SNP)位点与中国南方地区汉族人群2型糖尿病(T2DM)易感性关系中的应用特点。方法:采用BPANN分析方法,对591例2型糖尿病患者和724例正常对照者的基因多态性位点的分型结果、血清脂联素水平以及其他所有可能的影响因素按照平均影响值(MIV)的绝对值大小排序,并与Logistic回归模型的分析结果相比较,用多因子降维法(MDR)分析基因间的交互作用。结果:BPANN多因素分析中,2型糖尿病危险因子的顺位为血清脂联素浓度、高血压史、腰围、rs4240711、rs3132291、rs3856806、2型糖尿病家族史、饮酒、高脂血症史、吸烟、年龄、BMI指数、rs1045570、性别、rs2920502、rs6537944、rs4842194、rs17827276、rs1801282;而多因素Logistic回归分析中只有8个变量入选最终模型,因子顺位为高血压史、T2DM家族史、腰围、饮酒、吸烟、rs4240711、rs4842194、血清脂联素浓度;多因子降维法(MDR)分析结果显示模型X1X2X3(rs3856806,rs3132291,rs4240711)为最佳模型(交叉验证一致性10/10,P=0.0107)。结论:PPAR-γ和RXR-α基因多态性改变的交互作用对于中国南方汉族T2DM遗传易感性可能具有一定的作用。BPANN用于筛选T2DM等复杂多病因疾病的影响因素,可能提供更切合实际情况的模型。

联合多期增强CT纹理分析及血液学指标术前预测胃癌VEGFR2表达状态

目的探讨多期动态增强CT纹理分析参数联合血液学指标术前预测胃癌血管内皮生长因子受体2(vascu‐lar endothelial growth factor receptor2,VEGFR2)表达状态的价值。方法选取本院148例胃癌患者资料,获得术前血液学指标和三期增强CT纹理分析参数。基于组内相关系数和差异性检验对参数进行特征筛选。基于二元Logistic回归构建血液学模型、CT纹理分析模型及综合模型来预测VEGFR2表达状态。通过受试者工作特征曲线评估三个模型的诊断效能,并通过列线图来可视化地预测胃癌患者VEGFR2的表达状态。结果基于血液学指标构建的血液学模型曲线下面积(area under the curve,AUC)为0.687。由静脉期纹理分析参数构建的CT纹理分析模型的AUC值为0.624。联合血液学模型和CT纹理分析模型构建的综合模型AUC值为0.723。结论联合多期动态增强CT纹理分析参数及血液学指标有助于术前预测胃癌VEGFR2表达状态。

Transcriptome profiling and RXR gene family identification reveals the molecular mechanism of rapid aging after spawning of cuttlefish Sepiella japonica

Sepiella japonica is a worldwide marine cuttlefish species of high economic value.S.japonica routinely modifying behaviors in reproductive life,such as rapid aging until death after spawning,has been recognized in artificial breeding.However,reproductive behavior at the level of genes is rarely reported,thus,the research on the genetic basis of behavior,reproduction,and artificial breeding was limited.We applied RNA-seq in different stages of reproduction to investigate the reason of rapid aging after spawning,pre-maturity,pre-spawning after maturity,and post-spawning.The retinoid X receptor(RXR)gene family in S.japonica was identified,and 1343–1452 differentially expressed genes(DEGs)in all 3 stages of reproductive life were identified from pairwise m RNA comparisons.Furthermore,through the GO term and KEGG analysis,S.japonica could handle neuronal development and network formation before maturity and have a functional degradation of neural communication,signal transduction,vision,and gene expression after spawning.Eight Sj RXRαs have been identified and they played different roles in growth development or reproduction.Therefore,the regulation of several channels and receptors is the intrinsic molecular mechanism of rapid aging after spawning in S.japonica.This study revealed the survival strategy and provided fundamental data on the level of genes for understanding the reproductive behavior and the reproduction of S.japonica.

CT评分及白细胞介素34、可溶性白细胞介素2受体对活动性肺结核的诊断及预后预测价值

目的:探讨CT评分及白细胞介素34(IL-34)、可溶性白细胞介素2受体(SIL-2R)对活动性肺结核(ATB)的诊断价值及预后预测价值。方法:选取ATB患者2000例作为ATB组,同期选取500例非ATB患者为非ATB组。ATB组行抗结核治疗6个月,随访3年,其中预后不良538例和预后良好1462例。分析CT评分及IL-34、SIL-2R对ATB的诊断及预后预测价值。结果:ATB组CT评分、IL-34、SIL-2R均明显高于非ATB组(均P<0.05)。ROC曲线显示,CT评分、IL-34、SIL-2R及三者联合诊断ATB的AUC分别为0.859、0.820、0.876、0.932,CT评分最佳临界值对应的敏感度、特异度分别为64.2%、100.0%,IL-34为61.7%、100.0%,SIL-2R为72.7%、90.2%,三者联合为82.9%、90.6%。ATB组中预后不良患者的CT评分、IL-34、SIL-2R均明显高于预后良好患者(均P<0.05)。ROC曲线显示,CT评分、IL-34、SIL-2R、三者联合预测ATB预后不良的AUC分别为0.851、0.838、0.847、0.908,CT评分最佳临界值对应的敏感度、特异度分别为67.8%、90.1%,IL-34为54.8%、100.0%,SIL-2R为65.6%、88.4%,三者联合为84.8%、89.7%。结论:ATB患者CT评分、IL-34、SIL-2R呈高表达;预后越差,CT评分、IL-34、SIL-2R越高。CT评分、IL-34、SIL-2R三者联合对ATB具有较高的诊断价值及预后预测价值。

Gefapixant,a Novel P2X3 Antagonist,Protects against Post Myocardial Infarction Cardiac Dysfunction and Remodeling Via Suppressing NLRP3 Inflammasome

Objective The ATP responsive P2 purinergic receptors can be subdivided into metabotropic P2X family and ionotropic P2Y family.Among these,P2X3 is a type of P2X receptor which is specifically expressed on nerves,especially on pre-ganglionic sensory fibers.This study investigates whether gefapixant possesses the potential of inhibiting cardiac sympathetic hypersensitivity to protect against cardiac remodeling in the context of myocardial infarction.Methods The Sprague-Dawley rats were divided randomly into three groups:sham group-myocardial infarction group,and myocardial infarction with gefapixant treatment group.Myocardial infarction was induced by left anterior descending branch ligation.The gefapixant solution was intraperitoneally injected each time per day for 7 days and the appropriate dosage of gefapixant was determined according to the results of hematoxylin-eosin(HE)staining and myocardial injury biomarkers.Conditions of cardiac function were assessed by echocardiograph and cardiac fibrosis was evaluated by Western blotting and immunofluorescence staining of collagen I and collagen III.The sympathetic innervation was detected by norepinephrine concentration(pg/mL),in-vivo electrophysiology,and typical sympathetic biomarkers.Inflammatory cell infiltration was shown from immunofluorescence staining and pro-inflammatory signaling pathway activation was checked by immunohistology,quantitative realtime PCR(qPCR)and Western blotting.Results It was found that gefapixant injection of 10 mg/kg per day had the highest dosage-efficacy ratio.Furthermore,gefapixant treatment improved cardiac pump function as shown by increased LVEF and LVFS,and decreased LVIDd and LVIDs.The expression levels of collagen I and collagen III,and TNF-αwere all decreased by P2X3 inhibition.Mechanistically,the decreased activation of nucleotide-binding and oligomerization domain-like receptors family pyrin-domain-containing 3(NLRP3)inflammasome and subsequent cleavage of caspase-1 which modulated interleukin-1β(IL-1β)and IL-18 level in heart after gefapixant treatment were associated with the suppressed cardiac inflammation.Conclusion It is suggested that P2X3 inhibition by gefapixant ameliorates post-infarct autonomic nervous imbalance,cardiac dysfunction,and remodeling possibly via inactivating NLRP3 inflammasome.

Electroacupuncture diminishes P2X_2 and P2X_3 purinergic receptor expression in dorsal root ganglia of rats with visceral hypersensitivity

Electroacupuncture at Shangjuxu （ST37） and Tianshu （ST25） can improve visceral hypersensitivity in rats. Colorectal distension was used to establish a rat model of chronic visceral hypersensitivity. Immunohistochemistry was used to detect P2X2 and P2X3 receptor expression in dorsal root ganglia from rats with chronic visceral hypersensitivity. Results demonstrated that abdominal withdrawal reflex scores obviously increased following establishment of the model, indicating visceral hypersensitivity. Simultaneously, P2X2 and P2X3 receptor expression increased in dorsal root ganglia. After bilateral electroacupuncture at Shangjuxu and Tianshu, abdominal withdrawal reflex scores and P2X2 and P2X3 receptor expression decreased in rats with visceral hypersensitivity. These results indicated that electroacupuncture treatment improved visceral hypersensitivity in rats with irritable bowel syndrome by reducing P2X2 and P2X3 receptor expression in dorsal root ganglia.

Tagging single nucleotide polymorphisms in the PPAR-γ and RXR-α gene and type 2 diabetes risk:a case-control study of a Chinese Han population

Peroxisome proliferator-activated receptor （PPAR-γ）,which is mainly involved in adipocyte differentiation, has been suggested to play an important role in the pathogenesis of insulin resistance and atherosclerosis. We investigated the frequencies of two common tagging polymorphisms of the PPAR-γ gene and two of PPAR-α with minor allele frequency （MAF）≥ 0.05 in the Chinese Han population and analyzed the correlation between the different genotypes and the risk of type 2 diabetes mellitus （T2DM）. TaqMan assay was performed to test the genotypes in T2DM patients （n = 1,105） and normal controls （n = 1,107）. Serum adiponectin concentration was measured by ELISA kit. The variant genotypes rs17817276GG, rs3856806CT and rs3856806CT/TT of PPAR-γ were associated with T2DM, P = 0.023,0.037 and 0.018, respectively. Furthermore, the prevalence of haplotype GT in PPAR-γ was less frequent in the case subjects （0.3%） than in the controls （1.9%） [P 0.001,OR（95%CI）=0.13 （0.06-0.31）]. Patients with genotype TT of rs3856806 had a higher serum level of adiponectin than those with the genotype CC and CT （P = 0.031 and 0.038, respectively）. There was no statistically significant difference between patients and controls in genotype distribution of rs6537944 and rs1045570 of the RXR-α gene. The present study suggests that the variant genotypes in the PPAR-γ gene could decrease the risk for the development of T2DM in the Chinese Han population.

GW4064, a farnesoid X receptor agonist, upregulates adipokine expression in preadipocytes and HepG2 cells

AIM: To investigate the effect of GW4064 on the expression of adipokines and their receptors during differentiation of 3T3-L1 preadipocytes and in HepG2 cells.

Neural stem cell transplantation inhibits glial cell proliferation and P2X receptor-mediated neuropathic pain in spinal cord injury rats

P2X4 and P2X7 receptors play an important role in neuropathic pain after spinal cord injury. Regulation of P2X4 and P2X7 receptors can obviously reduce pain hypersensitivity after injury. To investigate the role of neural stem cell transplantation on P2X receptor-mediated neuropathic pain and explore related mechanisms, a rat model of spinal cord injury was prepared using the free-falling heavy body method with spinal cord segment 10 as the center. Neural stem cells were injected into the injured spinal cord segment using a micro-syringe. Expression levels of P2X4 and P2X7 receptors, neurofilament protein, and glial fibrillary acidic protein were determined by immunohistochemistry and western blot assay. In addition, sensory function was quantitatively assessed by current perception threshold. The Basso-Beattie-Bresnahan locomotor rating scale was used to assess neuropathological pain. The results showed that 4 weeks after neural stem cell transplantation, expression of neurofilament protein in the injured segment was markedly increased, while expression of glial fibrillary acidic protein and P2X4 and P2X7 receptors was decreased. At this time point, motor and sensory functions of rats were obviously improved, and neuropathic pain was alleviated. These findings demonstrated that neural stem cell transplantation reduced overexpression of P2X4 and P2X7 receptors, activated locomotor and sensory function reconstruction, and played an important role in neuropathic pain regulation after spinal cord injury. Therefore, neural stem cell transplantation is one potential option for relieving neuropathic pain mediated by P2X receptors.

Electroacupuncture at He-Mu points reduces P2X_4 receptor expression in 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,

Distribution of the P2X2 receptor and chemical coding in ileal enteric neurons of obese male mice(ob/ob)

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.

Role of P2X_7 receptors in the development of diabetic retinopathy

The P2X7 receptor is one of the members of the family of purinoceptors which are ligand-gated membrane ion channels activated by extracellular adenosine 5'-triphosphate. A unique feature of the P2X7 receptor is that its activation can result in the formation of large plasma membrane pores that allow not only the flux of ions but also of hydrophilic molecules of up to 900 Da. Recent studies indicate that P2X7-mediated signaling can trigger apoptotic cell death after ischemia and during the course of certain neurodegenerative disorders. Expression of the P2X7 receptor has been demonstrated in most types of cells in the retina. This purinoceptor mediates the contraction of pericytes and regulates the spatial and temporal dynamics of the vasomotor response through cell-to-cell electrotonic transmission within the microvascular networks. Of potential clinical significance, investigators have found that diabetes markedly boosts the vulnerability of retinal microvessels to the lethal effect of P2X7 receptor activation. This purinergic vasotoxicity may result in reduced retinal blood flow and disrupted vascular function in the diabetic retina. With recent reports indicating an association between P2X7 receptor activation and inflammatory cytokine expression in the retina, this receptor may also exacerbate the development of diabetic retinopathy by a mechanism involving inflammation.

Expression of the P2X_2 receptor in different classes of ileum myenteric neurons in the female obese ob/ob mouse

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.

Enteric nervous system and inflammatory bowel diseases:Correlated impacts and therapeutic approaches through the P2X7 receptor

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.

P2X7 receptor as the regulator of T-cell function in intestinal barrier disruption

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.

P2X4 receptor and brain-derived neurotrophic factor in neuropathic pain

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.