胆汁酸受体在消化道炎症和内脏感觉发生中的作用

胆汁酸除了辅助脂肪消化吸收外,还可作为一种信号分子作用于胆汁酸受体实现众多生物学效应。近来的研究表明,胆汁酸受体TGR5和FXR在消化道炎症和内脏感觉发生中发挥着重要作用。TGR5和FXR可以通过多种机制调控消化道炎症,并通过与TRP通道相关联从而对消化道内脏感觉进行调节。本文就TGR5和FXR在消化道炎症和内脏感觉发生中的作用作一概述。     

胆汁酸膜受体TGR5在胆道疾病中的研究进展

TGR5是一种胆汁酸激活的G蛋白偶联受体,在胆道系统生理及病理过程中发挥着重要作用。本文简述了在正常生理情况下,TGR5在肝脏及胆管中的正常表达情况,及发挥调节胆汁酸分泌、代谢,细胞保护作用等功能。归纳了在病理生理情况下,TGR5表达及功能的变化通过炎症反应、细胞增殖、凋亡等途径来影响疾病的发生与发展的机制。TGR5可能是未来治疗胆道疾病的潜在靶点。     

血管紧张素Ⅱ2型受体抑制小鼠骨髓源树突状细胞的成熟及活化

目的研究血管紧张素Ⅱ2型受体(AT2R)体外基因转染对小鼠骨髓源树突状细胞(BMDC)成熟活化及部分免疫功能的影响,探讨AT2R参与动脉粥样硬化斑块进展的免疫机制。方法取C57BL/6J小鼠骨髓,经分离、纯化、分化为BMDC,先转染带有绿色荧光蛋白报告基因的AT2R基因重组腺病毒载体(p Ad CMV/AT2R)或空病毒载体(p Ad-GFP),再用脂多糖刺激为成熟BMDC,分PBS对照组、脂多糖组、p Ad-GFP组、p Ad CMV/AT2R组及p Ad CMV/AT2R+PD123319组。采用RT-PCR、免疫荧光和激光共聚焦技术方法检测BMDC中AT2R mRNA及蛋白表达;流式细胞术检测BMDC表面标志CD86和MHCⅡ的表达率;液体闪烁计数检测BMDC刺激同源T淋巴细胞增殖的能力;ELISA法检测培养基中白细胞介素12(IL-12)和γ干扰素(IFNγ)的水平。结果 p Ad CMV/AT2R转染BMDC后48~72 h有AT2R mRNA表达,在激光共聚焦显微镜下胞浆及胞核有绿色荧光表达;同时在胞浆有红色荧光AT2R表达。与PBS对照组比较,p Ad CMV/AT2R组和p Ad CMV/AT2R+PD123319组CD86和MHCⅡ的表达、同源T淋巴细胞增殖和细胞因子分泌量都显著升高(P0.01),但p Ad CMV/AT2R组与脂多糖组比较显著降低(P0.01或P0.05),而p Ad CMV/AT2R+PD123319组与脂多糖组比较差异无显著性(P0.05)。结论体外基因转染BMDC能表达AT2R,AT2R能抑制BMDC成熟诱导的局部免疫炎性反应,且AT2R拮抗剂能阻断此效应,推测AT2R可能介导稳定斑块及抑制动脉粥样斑块进展的作用。     

三拗汤对人外周血来源的树突状细胞成熟的影响

目的探讨三拗汤对人外周血单核细胞来源的树突状细胞分化成熟的影响。方法采用体外培养人外周血单核细胞来源的未成熟树突状细胞,将细胞随机分为模型组和用药组,用药组加入三拗汤水煎液＋LPS;模型组加入相应体积的无菌双蒸水＋INS,在倒置相差显微镜下观察细胞的形态改变并计数。结果模型组成熟树突状细胞数量较多,细胞表面有许多毛刺状突起;而用药组未成熟树突状细胞较多,多数细胞仍为圆形,表面少有突起。两者比较有差异（P〈0．05）。结论三拗汤可抑制树突状细胞的分化和成熟。     

血吸虫抗原刺激小鼠骨髓来源的树突状细胞与DC2.4细胞的表型比较

目的 研究比较小鼠树突状细胞DC2.4和骨髓来源树突状细胞(bone marrow derived dendritic cell,BMDC)经血吸虫抗原谷胱甘肽转移酶(GST)刺激后表面分子的表达异同.方法 骨髓来源的细胞经白介素4(interleukin 4,IL-4)、粒细胞-巨噬细胞集落刺激因子(granuloc...     

小鼠骨髓成熟与未成熟树突状细胞的生物免疫学功能比较研究

目的比较成熟和未成熟状态小鼠骨髓树突状细胞（Dc）的生物免疫学功能的差异。方法粒细胞一巨噬细胞刺激因子（GM—CSF）和白细胞介素（IL）-4联合诱导培养小鼠骨髓未成熟Dc，经LPS刺激制备成熟Dc。分别收集培养第6天的两组Dc并用小鼠CD11c免疫磁珠纯化。电镜下观察成熟和未成熟DC的细胞形态。经流式细胞术检测两组细胞表面分子（MHC—Ⅱ、CD86和CD40）的表达水平。另将收集的DC分别与异基因小鼠脾脏T细胞共培养72h，四唑蓝（MTF）比色法检测T细胞增殖程度。取细胞上清液，液相芯片法检测Th1／Th2细胞因子表达水平。结果电镜下可见两组Dc在形态上存在很大差异。同成熟DC相比，未成熟DC细胞表面较光滑，细胞内存在大量的吞噬小泡。流式细胞术分析显示未成熟DC细胞表面3类分子（MHC—Ⅱ、CD86和CD40）的表达水平均明显低于成熟DC组。混合淋巴细胞反应（MLR）显示．未成熟DC刺激T细胞增殖显著低于相应反应比例的成熟DC，差异有统计学意义（P〈0．05）。细胞因子表达谱表明未成熟DC组分泌Th1细胞因子（IL-2和IFN-γ）较成熟DC组显著下降（P〈0．01）．Th2细胞因子相对占主导。结论未成熟DC倾向于诱导T细胞免疫耐受，有效抑制DC的成熟并维持DC的未成熟状态将有望用于治疗类风湿关节炎等由Th1细胞介导的自身免疫性疾病。     

小鼠泡型包虫囊液对小鼠骨髓来源树突状细胞表达IDO的影响

目的 探讨小鼠泡型包虫囊液(MCF)诱导小鼠骨髓来源树突状细胞(BMDCs)表达IDO的能力。方法 通过体外诱导培养获得BMDCs,分别与MCF(MCF组)、rmIFN-γ(阳性对照组)和RPMI-1640培养基(阴性对照组)进行共培养,在不同时间点收集各组BMDCs,采用Real-time PCR方法检测BMDCs表面IDO mRNA转录水平,Western blotting方法检测BMDCs表面IDO蛋白水平,ELISA方法检测BMDCs上清液中IDO浓度变化。结果 MCF组BMDCs表面IDO mRNA相对表达量和BMDCs上清液中IDO浓度在24 h达到峰值,明显高于阴性对照组(F=303.305,5752.473,P<0.01);而MCF组BMDCs表面IDO蛋白相对表达水平在48 h达到最高值,明显高于阴性对照组,差异有统计学意义(F=70.971,P<0.01)。结论 MCF具有上调BMDCs表面IDO表达的能力,为进一步揭示泡型包虫病的免疫耐受分子机制提供了理论依据。     

胆汁酸膜受体TGR5与代谢相关疾病的研究进展

随着人类生活水平的提高及生活方式的改变,与代谢相关的疾病患病率呈全球上升趋势。其发病机制不明,因而在治疗上还缺乏有效的手段.近来的研究发现胆汁酸膜受体TGR5为多种代谢性疾病的治疗提供了新的思路和方向。TGR5作为胆汁酸膜受体,对胆汁酸代谢、脂类及糖代谢、动脉粥样硬化具有重要的调控作用,对肝脏具有保护功能,故该因子有可能成为调控代谢紊乱的重要靶点。现将胆汁酸膜受体TGR5与代谢相关疾病的研究进展综述如下。     

快速老化模型小鼠树突状细胞的分化及其功能研究

目的研究机体老化对树突状细胞(DCs)分化和功能的影响,为抗衰老、老年性疾病的治疗提供新思路。方法体外培养快速老化小鼠(SAMP1)骨髓来源的DCs,同时用来自同一基因型的正常小鼠(C3H/HeJ)做对照,研究SAMP1小鼠的DCs分化能力及成熟DCs促淋巴细胞增殖的能力。结果流式细胞仪分析显示,SAMP1小鼠和C3H/HeJ小鼠骨髓来源的成熟DCs表达CD80和MHCⅡ类分子的能力无统计学差异。淋巴细胞的增殖实验结果提示伴刀豆球蛋白A(ConA)组和核苷酸(CPG)组差异无显著性,仅内毒素(LPS)组有显著差异,且老化小鼠具有更强的刺激能力。结论老化小鼠骨髓来源的DCs的分化及功能并无明显下降。     

Hepatoprotective impact of the bile acid receptor TGR5

During liver repair after injury, bile secretion has to be tightly modulated in order to preserve liver parenchyma from bile acid (BA)‐induced injury. The mechanisms allowing the liver to maintain biliary homeostasis during repair after injury are not completely understood. Besides their historical role in lipid digestion, bile acids (BA) and their receptors constitute a signalling network with multiple impacts on liver repair, both stimulating regeneration and protecting the liver from BA overload. BA signal through nuclear (mainly Farnesoid X Receptor, FXR) and membrane (mainly G Protein‐coupled BA Receptor 1, GPBAR‐1 or TGR5) receptors to elicit a wide array of biological responses. While a great number of studies have been dedicated to the hepato‐protective impact of FXR signalling, TGR5 is by far less explored in this context. Because the liver has to face massive and potentially harmful BA overload after partial ablation or destruction, BA‐induced protective responses crucially contribute to spare liver repair capacities. Based on the available literature, the TGR5 BA receptor protects the remnant liver and maintains biliary homeostasis, mainly through the control of inflammation, biliary epithelial barrier permeability, BA pool hydrophobicity and sinusoidal blood flow. Mouse experimental models of liver injury reveal that in the lack of TGR5, excessive inflammation, leaky biliary epithelium and hydrophobic BA overload result in parenchymal insult and compromise optimal restoration of a functional liver mass. Translational perspectives are thus opened to target TGR5 with the aim of protecting the liver in the context of injury and BA overload.     

The bile acid TGR5 membrane receptor: From basic research to clinical application

The TGR5 receptor (or GP-BAR1, or M-BAR) was characterized ten years ago as the first identified G-coupled protein receptor specific for bile acids. TGR5 gene expression is widely distributed, including endocrine glands, adipocytes, muscles, immune organs, spinal cord, and the enteric nervous system. The effect of TGR5 activation depends on the tissue where it is expressed and the signalling cascade that it induces. Animal studies suggest that TGR5 activation influences energy production and thereby may be involved in obesity and diabetes. TGR5 activation also influences intestinal motility. This review provides an overview of TGR5-bile acid interactions in health as well as the possible involvement of TGR5 in human disease.     

肝癌患者外周血树突状细胞免疫功能的研究

目的研究树突状细胞(DC)表面免疫分子 HLA-DR 及 B_7表达水平及其与 DC 免疫诱导能力相关性,并进一步探讨 DC 免疫功能在宿主免疫功能中的作用.方法以健康成人(n=10)作为对照,检测临床确诊肝癌患者(n=10)外周血 DC 表面免疫分子 HLA-DR 及 B_7表达水平及 DC 免疫诱导能力.结果肝癌患者 DC 表面 HLA-DR 及 B_7表达水平(6.7±1.6及6.1±1.1)明显低于对照组(10.7±1.4及9.6±1.2 VOF,P<0.05),其 DC 体外诱导 T细胞增殖能力(3100±120cpm)亦明显低于对照组(6200±90cpm,P<0.01);以抗 HLA-DR 单抗及抗 B_7单抗完全封闭对照组 DC 表面 HLA-DR 及 B_7。则该 DC 诱导 T 细胞增殖能力(3900±1.5cpm)亦明显低于对照组(6200±90cpm,P<0.05)。结论肝癌患者 DC 表面 HLA-DR 及 B_7表达水平下降与 DC 免疫功能低下密切相关,DC 免疫功能低下可能是肝癌(或许包括其它肿瘤)逃避宿主免疫监视的重要原因。     

TGR5 activation induces cytoprotective changes in the heart and improves myocardial adaptability to physiologic,inotropic, and pressure‐induced stress in mice

Introduction

Administration of cholic acid, or its synthetic derivative, 6‐alpha‐ethyl‐23(S)‐methylcholic acid (INT‐777), activates the membrane GPCR, TGR5, influences whole body metabolism, reduces atherosclerosis, and benefits the cardiovascular physiology in mice. Direct effects of TGR5 agonists, and the role for TGR5, on myocardial cell biology and stress response are unknown.

Methods

Mice were fed chow supplemented with 0.5% cholic acid (CA) or 0.025% INT‐777, a specific TGR5 agonist, or regular chow for 3 weeks. Anthropometric, biochemical, physiologic (electrocardiography and echocardiography), and molecular analysis was performed at baseline. CA and INT‐777 fed mice were challenged with acute exercise‐induced stress, acute catecholamine‐induced stress, and hemodynamic stress induced by transverse aortic constriction (TAC) for a period of 8 weeks. In separate experiments, mice born with constitutive deletion of TGR5 in cardiomyocytes (CM‐TGR5^del) were exposed to exercise, inotropic, and TAC‐induced stress.

Results

Administration of CA and INT‐777 supplemented diets upregulated TGR5 expression and activated Akt, PKA, and ERK1/2 in the heart. CA and INT‐777 fed mice showed improved exercise tolerance, improved sensitivity to catecholamine and attenuation in pathologic remodeling of the heart under hemodynamic stress. In contrast, CM‐TGR5^del showed poor response to exercise and catecholamine challenge as well as higher mortality and signs of accelerated cardiomyopathy under hemodynamic stress.

Conclusions

Bile acids, specifically TGR5 agonists, induce cytoprotective changes in the heart and improve myocardial response to physiologic, inotropic, and hemodynamic stress in mice. TGR5 plays a critical role in myocardial adaptability, and TGR5 activation may represent a potentially attractive treatment option in heart failure.

     

雷帕霉素对人树突状细胞功能的影响

目的　研究雷帕霉素 (RPM)对人树突状细胞 (DC)功能的影响。方法　分离外周血单个核细胞 (PBMC) ,在含粒细胞巨噬细胞集落刺激因子 (GM CSF)、白介素 4 (IL 4 )以及有或无RPM的培养条件下制备DC。用流式细胞仪检测DC表面共刺激分子CD86 (B7 2 )的表达 ;混合淋巴细胞反应(MLR)检测DC对同种异体T淋巴细胞的刺激能力 ;ELISA法测定MLR上清液中的细胞因子。结果　与对照组比较 ,经RPM处理的DC表面CD86的表达明显降低 ;对T淋巴细胞刺激的能力下降 ;MLR中致炎细胞因子 (IL 1β ,IL 6 ,TNF a)浓度降低。RPM的这些作用呈浓度依赖性。 结论　雷帕霉素对人树突状细胞功能有明显的抑制作用 ,可能是其防止支架术后再狭窄的机制之一     

Increased generation of pre-plasmacytoid dendritic cells in bone marrow of rheumatoid arthritis

Abstract

Objective. Plasmacytoid dendritic cells (pDCs) have been found to be accumulated in synovial tissues in rheumatoid arthritis (RA). Since pDCs originate from bone marrow (BM), we explored the differentiation of pDC in BM in RA and osteoarthritis (OA).

Methods. BM mononuclear cells (BMMNCs) of the posterior ileac crest from 25 RA patients and 22 OA patients were examined for the expression of BDCA2 and CD34 by flow cytometry. The degree of synovial proliferation was assessed on light microscopy in 10 of 25 RA patients.

Results. There were no significant differences in percentages of CD34 + cells or BDCA2 + cells within BMMNC between RA and OA. However, RA BMMNC contained higher percentages of BDCA2 + CD34 + cells (pre-pDCs) than OA BMMNCs. Accordingly, percentages of BDCA2 + CD34+ cells within BM CD34 + cells were significantly higher in RA than in OA. Finally, the percentages of BDCA2 + CD34+ cells within BM CD34 + cells were significantly correlated with the degree of synovial proliferation in RA.

Conclusion. These results indicate that the generation of pre-pDC from BM CD34 + cells is increased in RA compared with OA. Moreover, the data suggest that the increased output of pDC from BM might be involved in the synovial proliferation in RA.     

Expression and function of phosphoinositide 3-kinase delta in mesenchymal stromal cells from normal and leukaemic bone marrow

Within lymphoid tissues, chronic lymphocytic leukaemia (CLL) cells interact with mesenchymal stromal cells (MSC). Inhibitors of phosphoinositide 3-kinase delta (PI3Kδ) cause release of CLL cells from lymphoid tissues into blood. PI3Kδ inhibitors are thought to target only CLL and other immune cells because PI3Kδ expression is restricted to haematopoietic cells. We found that PI3Kδ is unexpectedly expressed in primary MSC derived from CLL patients and healthy donors. PI3Kδ inhibition in MSC using idelalisib or duvelisib significantly reduced their ability to support CLL migration and adhesion. These observations provide the first evidence that PI3Kδ is expressed and functional in CLL MSC.     

Intestinal dendritic cells in the pathogenesis of inflammatory bowel disease

The gastrointestinal tract harbors a large number and diverse array of commensal bacteria and is an important entry site for pathogens.For these reasons,the intestinal immune system is uniquely dedicated to protect against infections,while avoiding the development of destructive inflammatory responses to the microbiota.Several models have been proposed to explain how the immune system discriminates between,and appropriately responds to,commensal and pathogenic microorganisms.Dendritic cells(DCs)and regulato...