Toll样受体(TLR)2、TLR4和TLR9在大鼠结肠炎模型结肠组织中的表达及其意义

Toll样受体（TLRs）家族可能在一系列免疫性疾病中发挥重要作用。目的：观察TLR2、TLR4和TLR9在大鼠结肠炎模型结肠组织中的表达，探讨三者在炎症性肠病（IBD）发病机制中的作用。方法：以三硝基苯磺酸（TNBS）＋乙醇灌肠制备大鼠结肠炎模型，观察和评估结肠黏膜的大体和组织学变化。分别以黄嘌呤氧化酶法和紫外分光光度法测定超氧化物歧化酶（SOD）和髓过氧化物酶（MPO）活性；以免疫组化方法检测TLR2、TLR4和TLR9的表达，以逆转录聚合酶链反应（RT-PCR）检测三者mRNA的表达。结果：造模后结肠组织中可见大量炎性细胞浸润，累及黏膜下层和固有层。与正常对照组相比，模型组结肠组织SOD活性显著降低（P〈0．01），MPO活性显著升高（P〈0．01）。正常对照组结肠黏膜下层和固有层炎性细胞胞膜和胞质仅有少量TLR2、TLR4表达，未见TLR9表达；模型组三者表达均显著增加（P〈0．01），此外还可见TLR2表达于肠上皮近肠腔侧胞膜，TLR4表达于肠上皮近肠腔侧胞膜和腺上皮近腺腔侧胞膜。模型组结肠组织可见TLR2、TLR4、TLR9 mRNA表达，而正常对照组未检出三者mRNA的表达。TLR2、TLR4、TLR9的表达与MPO活性呈正相关（P〈0．05），与SOD活性呈负相关（P〈0．01）。结论：大鼠结肠炎模型结肠组织中TLR2、TLR4和TLR9表达明显增加，可能与结肠的自身免疫损伤有关。     

β-arrestin 2对急性支气管哮喘小鼠模型脾CD4^＋T细胞T-bet表达的影响

目的探讨β-arrestin 2在急性支气管哮喘（简称哮喘）小鼠模型脾CD4＋T细胞中的表达及对T-bet表达的影响。方法建立急性哮喘小鼠模型,免疫磁珠分离小鼠脾源性CD4＋T细胞,RNA干扰β-arrestin 2的表达后,检测CD4＋T细胞β-arrestin 2、T-bet mRNA和蛋白的表达。结果 siRNA-β-arrestin 2-1123沉默效果最佳,相对于未转染siRNA的哮喘组及其他siRNAβ--arrestin 2转染组,β-arrestin 2 mRNA明显降低（P〈0.01）;哮喘小鼠模型脾CD4＋T细胞β-arrestin 2蛋白的表达明显高于正常组（P〈0.01）;β-arrestin 2沉默后,哮喘小鼠脾CD4＋T细胞T-bet mRNA和蛋白的表达明显升高（P〈0.05）。结论β-arrestin 2可能通过抑制小鼠CD4＋T细胞T-bet的表达参与哮喘的发病。     

三硝基苯磺酸和噁唑酮诱导肠炎小鼠脾脏中Th1/Th2类细胞因子基因表达的动态研究

目的 对比研究三硝基苯磺酸（TNBS）和 唑酮（OXZ）诱导的实验性小鼠肠炎模型脾脏中Th1／Th2类细胞因子基因表达的动态变化。方法 雌性BALB／c小鼠，随机分为50％乙醇对照组，OXZ诱导肠炎模型组，TNBS诱导肠炎模型组（保证每组小鼠取材时6只以上）。采用RT—PCR方法观察OXZ和TNBS诱导肠炎后小鼠脾脏于3及7d IFN-γ、IL-4 mRNA的表达变化。结果 TNBS模型组小鼠在造模后3及7d脾脏中IFN-γ mRNA的表达量均高于OXZ模型组（P〈0．05），IL-4 mRNA的表达量低于OXZ模型组（P〈0．05）。结论 在造模后3和7d TNBS模型小鼠的外周免疫皆以Th1型为主，OXZ模型小鼠的外周免疫以Th2型为主，可代表肠道局部免疫类型。     

白介素23受体在支气管哮喘小鼠脾源性CD4^＋T细胞中的表达及意义

-23R）的表达及在哮喘发病中的作用。方法建立急性哮喘小鼠模型,免疫磁珠分离小鼠脾源性CD4^＋T细胞,培养24h后,检测CD4^＋T细胞表面IL-23R的表达、Th17细胞的阳性率及细胞培养上清液中的IL-17水平。结果哮喘小鼠脾脏CD4^＋T细胞表面IL-23R的表达明显高于正常组（P〈0．01）;哮喘小鼠脾脏CD4^＋T细胞中Th17细胞的阳性率明显高于正常组（P〈0．01）;哮喘小鼠脾脏CD4^＋T细胞分泌IL-17浓度明显高于正常组（P〈O．01）;小鼠脾脏CD4^＋T细胞表面IL-23R的表达与Th17细胞的阳性率和IL-17的浓度呈正相关。结论IL-23R在急性哮喘的发病机制中可能起重要作用。     

支气管哮喘小鼠模型中维生素D相关分子的表达

目的探讨维生素D相关分子在支气管哮喘（简称哮喘）小鼠模型中的表达及地塞米松的干预效果。方法用卵白蛋白作为致敏原制备小鼠哮喘模型,随机分为两组（n=6）,分别为地塞米松处理组和生理盐水处理组（对照组）,收集各组小鼠的支气管肺泡灌洗液和支气管组织,计数总细胞数和白细胞分类数,采用real—time RT-PCR技术检测支气管组织中维生素D3上调蛋白1（VDUP1）、维生素D受体（VDR）和1口羟化酶CYP27B1的mRNA表达水平。结果哮喘组支气管组织中VDUP,mRNA、VDRmRNA和CYP27B1mRNA水平分别为（2．74±0．99）、（7．06±4．05）和（3．40±2．16）,明显高于对照组（分别为1．01±0．18、1．28±0．76、1．45±1．39,P〈0．05）和地塞米松治疗组（分别为0．94±0．34、0．76±0．18、0．27±0．17,P〈0．01）。结论维生素D相关分子可能参与了哮喘的发病过程。     

吡格列酮对NOD鼠糖尿病的预防作用及其机制探讨

目的探讨吡格列酮（PIO）对NOD鼠糖尿病发病率和胰岛炎的影响及其作用机制。方法4周龄NOD雌鼠随机分为2组，分别摄食0．02％PIO混合饲料（PIO，n=26）和普通饲料（对照组，n=25），观察30周龄时的糖尿病累积发病率。各组另取12周龄未患病NOD鼠（n=15）胰腺H～E染色观察胰岛炎；ELISA法测血清、脾细胞培养上清干扰素γ（IFN-γ）和白细胞介素4（IL～4）水平；RT-PCR检测脾脏IL-4、IFN～γmRNA的表达水平。结果30周龄时，PIO组发病率较对照组明显降低（P〈0．05）。12周龄时，PIO组胰岛炎平均积分低于对照组（P〈0．05）；血清、脾上清IL～4水平，脾脏IL-4mRNA表达水平显著性高于对照组（P〈0．05）；PIO血清、脾上清IL-4／IFN-γ比值水平高于对照组（P〈0．05）。结论PIO通过上调IL～4水平，促使免疫平衡向Th2方向偏移，从而使NOD鼠胰岛炎减轻，而在一定程度上预防和延缓NOD鼠糖尿病的发生。     

肺炎支原体感染小鼠Th1／Th2平衡状况及Tim-3mRNA的表达

目的通过检测Tim-3mRNA的表达水平及IFN-7、IL-4的含量,初步探讨肺炎支原体感染鼠Th1／Th2细胞的动态变化及Tim～3的免疫调控作用。方法通过滴鼻感染建立肺炎支原体肺炎小鼠模型,观察小鼠的一般状况,分别于感染后3d、5d、7d、14d、21d取材,应用RT—PCR方法检测肺组织和脾脏Tim-3mRNA的表达;采用ELISA法检测肺泡灌洗液中细胞因子IFN～γ、IL-4的含量。结果实验组IFN-γ于3d出现升高（t=2．309,P〈0．05）,5dIFNY开始下降,而IL-4于3d开始升高并一直持续到7d（t-6．436,P〈0．05）,之后逐渐恢复正常,肺组织和脾脏Tim-3mRNA的表达均于5d达到峰值（t=4．727,P〈0．05;t=7．962,P〈0．05）,且肺组织和脾脏Tim-3mRNA表达量与L-4呈正相关（r=0．561,P〈0．05;r=0．462,P〈0．05）,从5d开始与IFN-γ呈负相关（r=0．379,P〈0．05;r=0．431,P〈0．05）。结论小鼠感染肺炎支原体后Th1／Th2失衡,以Th2介导的免疫反应为主;Tim3可能参与了感染后对Th1细胞的负调控。     

大黄牡丹汤含药血清对 LPS 刺激的小鼠肺巨噬细胞 TLR4和 MyD88表达的影响

目的：探讨大黄牡丹汤含药血清（以下简称含药血清）对脓毒症的治疗机制。方法体外培养小鼠肺巨噬细胞株RAW264．7并随机分为空白组,模型组,含药血清高、中、低浓度组,每组3个复孔。除空白组外,其余四组均予细菌脂多糖（ LPS）5μg/mL刺激24 h,含药血清高、中、低浓度组分别同时给予高、中、低浓度的含药血清进行干预。干预后于37℃、5％CO2培养箱中培养24 h。分别采用半定量RT-PCR和Western blot法测定Toll样受体4（TLR4）及髓样分化因子88（MyD88）mRNA和蛋白表达。结果模型组TLR4和MyD88 mRNA和蛋白表达均显著高于空白组（P＜0．01）;含药血清中浓度组与高浓度组TLR4和MyD88表达无显著差异,但均显著低于模型组（P＜0．01）。结论含药血清治疗脓毒症的机制可能为抑制TLR4和下游MyD88表达。     

感染旋毛虫小鼠不同时期TLR2/TLR4 mRNA表达量及血清炎性因子的变化

目的 探讨旋毛虫感染对小鼠不同组织细胞TLR2/ TLR4（Toll样受体）表达量及血清炎性因子的影响.方法 分别取感染前、后不同时期小鼠心肌、肺及腹腔巨噬细胞,应用半定量PCR方法检测TLR2/ TLR4 mRNA相对表达量,同时应用ELISA方法对血清相关炎性因子进行检测.结果 随着旋毛虫感染时间的变化,TLR4和TLR2在心肌、肺和腹腔巨噬细胞上的表达略有不同,但大致呈双峰状.旋毛虫感染初期4d左右,TLR2/ TLR4 mRNA表达均有不同程度升高,之后降低,14 d左右,心肌与肺TLR升高,巨噬细胞TLR则继续下降,在21 d左右,心肌TLR表达量达到最高值,且与对照组差异显著（P＜0.05）,肺组织TLR呈下降趋势,巨噬细胞TLR表达升高,之后下降并趋于稳定.感染鼠的血清中炎性因子IL 2和NO的表达量显著升高（P＜0.05）,而TNF-α、IL-10和IL-12的表达量则显著降低（P＜0.05）,IL-6的表达量变化不明显.结论 旋毛虫感染可引起小鼠心肌、肺和巨噬细胞上的Toll样受体TLR2/TLR4表达发生变化,继而调节相关细胞因子分泌也发生变化,这种变化与旋毛虫生活史不同阶段抗原及其引起的宿主免疫反应和组织器官损伤具有一定相关性.     

变应性鼻炎和哮喘患者血清IL-9、IL-4、IL-5变化及临床意义

目的探讨血清IL-9、IL-4、IL-5在变应性鼻炎、支气管哮喘（哮喘）、变应性鼻炎合并哮喘中的作用。方法采用双抗体夹心ELISA法检测哮喘组、过敏性鼻炎组、过敏性鼻炎合并哮喘（合并组）患者及查体健康者（对照组）的血清IL-9、IL-4、IL-5。结果与对照组比较,三组患者的血清IL-4、IL-5、IL-9均明显升高（P均〈0．01）;其中血清IL-5合并组高于哮喘组及过敏性鼻炎组（P〈0．01,〈0．05）,过敏性鼻炎组高于哮喘组（P〈0．01）;IL-4合并组高于哮喘组（P〈0．05）。结论IL-4、IL-5、IL-9参与过敏性鼻炎和哮喘的发病,三组患者均表现为Th2型细胞因子过度表达;变应性鼻炎合并哮喘的炎症程度较高,哮喘和鼻炎也有不同炎症反应。     

TLR4-dependent hepcidin expression by myeloid cells in response to bacterial pathogens

Hepcidin is an antimicrobial peptide secreted by the liver during inflammation that plays a central role in mammalian iron homeostasis. Here we demonstrate the endogenous expression of hepcidin by macrophages and neutrophils in vitro and in vivo. These myeloid cell types produced hepcidin in response to bacterial pathogens in a toll-like receptor 4 (TLR4)-dependent fashion. Conversely, bacterial stimulation of macrophages triggered a TLR4-dependent reduction in the iron exporter ferroportin. In vivo, intraperitoneal challenge with Pseudomonas aeruginosa induced TLR4-dependent hepcidin expression and iron deposition in splenic macrophages, findings mirrored in subcutaneous infection with group A Streptococcus where hepcidin induction was further observed in neutrophils migrating to the tissue site of infection. Hepcidin expression in cultured hepatocytes or in the livers of mice infected with bacteria was independent of TLR4, suggesting the TLR4-hepcidin pathway is restricted to myeloid cell types. Our findings identify endogenous myeloid cell hepcidin production as a previously unrecognized component of the host response to bacterial pathogens.     

模拟代谢性内毒素血症对肝损伤小鼠肝组织TLR4信号通路的影响

目的：观察持续4 w的模拟代谢性内毒素血症对小鼠肝脏组织病理和4型Toll样受体（TLR4）信号通路的影响。方法将30只雄性C57BL/6J 小鼠随机分为正常组（n=10）和内毒素组（n=10）,均予以普通饲料喂养,和高脂组（n=10）,予以高脂饲料喂养。内毒素组小鼠同时经腹部皮下植入的微泵注入内毒素300μg·kg-1·d-1,连续4 w,正常组小鼠皮下微泵持续注入生理盐水作为对照。4 w后测定小鼠血清内毒素水平,对肝组织切片行HE染色后进行非酒精性脂肪性肝病评分（NAS）,采样Real time PCR法测定小鼠肝组织TLR4及其下游的MyD88和TRIF-related adaptor molecule （TRAM） mRNA水平。结果内毒素组小鼠血清内毒素水平（0.62±0.04 EU/ml）显著高于正常组（0.50±0.06 EU/ml,P〈0.05）和高脂组（0.49±0.05 EU/ml,P〈0.05）;内毒素组小鼠肝组织主要表现为单纯性脂肪变性,NAS积分为（2.30±0.49）,高脂组小鼠肝组织炎症较明显,NAS积分为（4.20±1.61）,显著高于内毒素组（P〈0.05）;与正常组相比,内毒素组小鼠肝组织TLR4 mRNA 水平上调5.12倍（P＜0.01）,TRAM mRNA水平上调3.46倍（P＜0.01）,而MyD88 mRNA水平与正常组比,无显著差别。结论持续4 w的模拟代谢性内毒素血症可诱导小鼠肝脏单纯性脂肪变性,TLR4 mRNA 和TRAM mRNA水平上调,而MyD88 mRNA水平无显著变化。     

白蛋白治疗对小鼠脑缺血早期脑组织Toll样受体4和骨髓分化因子88 mRNA表达的影响

目的研究人血白蛋白治疗对局灶性脑缺血再灌注小鼠脑组织Toll样受体4(TLR4)和骨髓分化因子88(MyD88)mRNA表达的影响。方法健康雄性成年昆明小鼠54只,随机分为假手术组(14只)、生理盐水组(20只)和白蛋白组(20只),每组又均分为再灌后6、24 h 2个时间点。采用左侧大脑中动脉线栓法制备小鼠局灶性脑缺血再灌注模型,RT-PCR法检测左侧脑组织TLR4、MyD88 mRNA的表达水平,并进行神经功能缺损评分。结果生理盐水组和白蛋白组脑缺血再灌注后6、24 h TLR4、MyD88 mRNA表达水平明显高于假手术组,且24 h表达水平升高更明显(P<0.05);但白蛋白组6、24 h TLR4、MyD88 mRNA表达量明显低于生理盐水组(P<0.05);24 h白蛋白组小鼠的神经功能缺损评分与生理盐水组比较有明显改善(P<0.05);24 h TLR4、MyD88 mRNA表达水平与神经功能缺损评分呈正相关(r=0.92,r=0.85,P<0.05)。结论白蛋白治疗可以下调脑缺血早期脑组织高表达的TLR4、MyD88 mRNA的水平,改善脑缺血后小鼠神经功能缺损。     

TLR2/6 and TLR4-activated macrophages contribute to islet inflammation and impair beta cell insulin gene expression via IL-1 and IL-6

Aims/hypothesis

Inflammation contributes to pancreatic beta cell dysfunction in type 2 diabetes. Toll-like receptor (TLR)-2 and -4 ligands are increased systemically in recently diagnosed type 2 diabetes patients, and TLR2- and TLR4-deficient mice are protected from the metabolic consequences of a high-fat diet. Here we investigated the role of macrophages in TLR2/6- and TLR4-mediated effects on islet inflammation and beta cell function.

Methods

Genetic and pharmacological approaches were used to determine the effects of TLR2/6 and TLR4 ligands on mouse islets, human islets and purified rat beta cells. Islet macrophages were depleted and sorted by flow cytometry and the effects of TLR2/6- and TLR4-activated bone-marrow-derived macrophages (BMDMs) on beta cell function were assessed.

Results

Macrophages contributed to TLR2/6- and TLR4-induced islet Il1a/IL1A and Il1b/IL1B mRNA expression in mouse and human islets and IL-1β secretion from human islets. TLR2/6 and TLR4 ligands also reduced insulin gene expression; however, this occurred in a non-beta cell autonomous manner. TLR2/6- and TLR4-activated BMDMs reduced beta cell insulin secretion partly via reducing Ins1, Ins2, and Pdx1 mRNA expression. Antagonism of the IL-1 receptor and neutralisation of IL-6 completely reversed the effects of activated macrophages on beta cell gene expression.

Conclusions/interpretation

We conclude that islet macrophages are major contributors to islet IL-1β secretion in response to TLR2/6 and TLR4 ligands. BMDMs stimulated with TLR2/6 and TLR4 ligands reduce insulin secretion from pancreatic beta cells, partly via IL-1β- and IL-6-mediated decreased insulin gene expression.     

The role of toll-like receptor (TLR) 2 and TLR4 in the host defense against disseminated candidiasis

Toll-like receptors (TLRs) represent the main class of pattern-recognition receptors involved in sensing pathogenic microorganisms. The aim of the present study was to assess the role of TLR4 in the defense against Candida albicans infection. The outgrowth of C. albicans was 10-fold higher in TLR4-defective C3H/HeJ mice, compared with that in control C3H/HeN mice (P<.05). Production of tumor necrosis factor (TNF) and interleukin (IL)-1alpha and IL-1beta by mouse macrophages in response to C. albicans stimulation was not affected by TLR4, and the candidacidal capacities of the neutrophils and macrophages of C3H/HeJ mice were normal. In contrast, production of the CXC chemokines KC and macrophage inhibitory protein-2 was 40%-60% lower by the macrophages of C3H/HeJ mice (P<.05), which resulted in a 40% decrease in neutrophil recruitment to the site of infection. Candida-induced TNF and IL-1beta production by human peripheral blood mononuclear cells was significantly inhibited by blocking anti-TLR2 antibodies in vitro. In conclusion, TLR4-defective C3H/HeJ mice are more susceptible to C. albicans infection, and this is associated with impaired chemokine expression and neutrophil recruitment.     

Selective priming to Toll-like receptor 4 (TLR4), not TLR2, ligands by P. acnes involves up-regulation of MD-2 in mice

Lipopolysaccharide (LPS) triggers cytokine production through Toll-like receptor 4 (TLR4), which shares downstream signaling pathways with TLR2. We investigated the roles of TLR2 and TLR4 in Propionibacterium acnes (P. acnes)-primed, LPS-induced liver damage using selective TLR ligands. Stock LPS induced interleukin 8 in both TLR4- and TLR2-expressing human embryonic kidney (HEK) 293 cells. Purified LPS (TLR4 ligand) activated HEK/TLR4 cells, while peptidoglycan and lipoteichoic acid (TLR2 ligands) activated HEK/TLR2 cells, respectively. In mice, P. acnes priming resulted in increased liver messenger RNA (mRNA) and serum levels of tumor necrosis factor alpha, interleukin 12, and interferon gamma (IFN-gamma) by both stock LPS and purified LPS challenges compared with nonprimed controls. In contrast, P. acnes failed to sensitize to TLR2 ligands (peptidoglycan + lipoteichoic acid). In the liver, P. acnes-priming was associated with up-regulation of TLR4 and MD-2 proteins, and subsequent LPS challenge further increased MD-2 and CD14 mRNA levels. The lack of sensitization to TLR2 ligands by P. acnes correlated with no increase in hepatic TLR1 or TLR6 mRNA. In vitro, P. acnes pretreatment desensitized RAW macrophages to a secondary stimulation via both TLR2 and TLR4. However, IFN-gamma could selectively prevent desensitization to TLR4 but not to TLR2 ligands. Furthermore, P. acnes induced production of IFN-gamma in vivo as well as in isolated splenocytes. In vitro, P. acnes-primed Hepa 1-6 hepatocytes but not RAW macrophages produced increased MD-2 and CD14 mRNA levels after an LPS challenge. In conclusion, P. acnes priming to selective TLR4-mediated liver injury is associated with up-regulation of TLR4 and MD-2 and is likely to involve IFN-gamma and prevent TLR4 desensitization by P. acnes.     

库普弗细胞Toll样受体2在小鼠肝脏缺血再灌注损伤中的表达及意义

目的探索库普弗细胞Toll样受体2(TLR2)在肝脏缺血再灌注损伤中的表达变化,分析库普弗细胞TLR2信号通路参与肝脏缺血再灌注损伤的机制。方法动物分假手术对照(SH)组、缺血再灌注(I/R)组及氯化钆处理(Gd)组,复制小鼠肝脏部分缺血1 h再灌注4 h损伤模型,结束再灌注后,取缺血叶肝脏组织及其库普弗细胞,提取总RNA及膜蛋白质分析TLR 2 mRNA及蛋白的表达,同时提取缺血肝叶组织核蛋白分析核因子(NF—κB),并检测门静脉血中肿瘤坏死因子(TNF α)、丙氨酸氨基转移酶(ALT) 及内毒素水平。结果再灌注4 h,(1)I/R组缺血肝叶TLR2 mRNA及蛋白表达水平较SH组高,△Ct值分别为1.06±0.91和5.08±1.32,t=7.80,P<0.01;A值分别为433.91±25.53和102.86±13.58,t=28.04, P<0.01。Gd组缺血肝叶TLR2 mRNA及蛋白表达水平较I/R组下降,△Ct值分别为4.22±0.84和1.06±0.91,t=7.56,P<0.01;A值分别为125.89±15.49和433.91±25.53,t=25.27,P<0.01。(2)I/R组缺血肝叶库普弗细胞中TLR2 mRNA及蛋白表达水平较SH组高,△Ct值分别为0.52±0.23和2.61±0.1 8, t=17.47,P<0.01;A值分别为379.70±34.16和114.98±21.90,t=15.98,P<0.01。Gd组缺血肝叶库普弗细胞中TLR2 mRNA及蛋白表达水平则较I/R组下降,△Ct值分别为1.90±0.14和0.52±0.23,t= 12.     

萝卜硫素对慢阻肺患者TLR4、MyD88以及下游炎性因子的影响分析

目的探讨萝卜硫素对慢性阻塞性肺病(简称:慢阻肺)患者Toll样受体(TLR4)、髓样分化因子88(My D88)及炎性因子的影响作用。方法选取40例稳定期慢阻肺患者作为病例组,同期健康体检者40例作为健康组,采集患者外周静脉血,分离单核细胞,诱导形成单核细胞源性巨噬细胞(MDM),将MDM分为脂多糖、萝卜硫素、萝卜硫素+脂多糖、及不处理(空白组)。健康组不给予任何处理措施,采用实时荧光聚合酶链反应(PCR)检测TLR4 mRNA、My D88 mRNA,免疫荧光染色法检测TLR4、My D88蛋白,采用ELISA法检测炎性因子肿瘤坏死因子-ɑ(TNF-ɑ)、白细胞介素-6(IL-6)。结果慢阻肺患者的TLR4 mRNA、My D88 mRN、蛋白表达到水平显著高于健康组(P0.05),不同处理方式下慢阻肺患者TLR4 mRNA、My D88 mRNA、蛋白表达水平组间比较为脂多糖组空白组萝卜硫素+脂多糖萝卜硫素组且差异均具有统计学意义(P0.05)。慢阻肺患者的TNF-ɑ、IL-6表达水平显著的高于健康组(P0.05),不同处理方式下慢阻肺患者TNF-ɑ、IL-6表达水平组间比较结果为脂多糖组空白组萝卜硫素+脂多糖萝卜硫素组且差异均具有统计学意义(P0.05)。结论慢阻肺患者的外周血巨噬细胞Toll样受体(TLR4)、髓样分化因子88(My D88)高表达,萝卜硫素可以降低TLR4、My D88、高表达,从而减轻慢阻肺患者的炎症反应。     

细胞表面Toll样受体4在小鼠急性坏死性胰腺炎中的作用

目的 探索髓系细胞(中性粒细胞、血小板)及内皮细胞表面Toll样受体4(toll-like receptor 4,TLR4)表达在小鼠急性坏死性胰腺炎(ANP)中性粒细胞招募中的作用.方法 将C3H/He-J和C3H/He-N小鼠通过骨髓移植的方法制作髓系细胞TLR4-/一和内皮细胞TLR4+/+、髓系细胞TLR4+/+和内皮细胞TLR4+/+、髓系细胞TLR4+/+和内皮细胞TLR4-/-、髓系细胞TLR4-/-和内皮细胞TLR4-/-4组嵌入体或纯合体小鼠,另设1个对照组.腹腔注射蛙皮素、尾静脉注射脂多糖复制ANP模型.榆测血清淀粉酶含量,行胰腺病理检查、胰腺组织萘酚AS-D氯乙酸脂酶染色计数、髓过氧化物酶(MPO)活性测定、TLR4蛋白表达检测及RT-PCR检测外周血粒细胞TLR4 mRNA表达.结果 各实验组小鼠血清淀粉酶均较对照组显著升高,但组间无显著性差异.4个实验组胰腺病理分值分别为5.52±1.21、5.18±1.02、2.03±0.82、1.92±0.78;胰腺MPO水平分别为(1.834±0.170)U/g、(2.596±0.138)U/g、(0.367±0.018)U/g、(0.202±0.018)U/g;AS-D计数分别为(66.88±2.17)个、(75.00±2.43)个、(21.50±2.38)个、(20.00±2.19)个;外周血粒细胞TLR4 mRNA表达量分别为0.037±1.047E-2、1.489±8.084 E-2、1.470±5.210E-2、0.017±6.668 E-3;内皮细胞TLR4+/+的2组小鼠胰腺内血管内皮细胞TLR4蛋白强阳性表达,内皮细胞TLR4-/-的2组不表达.内皮细胞TLR4+/+的2组小鼠的胰腺损伤、MPO活性、AS-D计数及TLR4蛋白表达均显著高于内皮细胞TLR4-/-的2组小鼠.结论 内皮细胞而非外周血粒细胞在ANP中性粒细胞聚集及病理损伤中起关键作用.     

Increased lipopolysaccharide sensitivity in alcoholic fatty livers is independent of leptin deficiency and toll-like receptor 4 (TLR4) or TLR2 mRNA expression

BACKGROUND: Both alcoholic (AFL) and nonalcoholic (NAFL) fatty livers show increased sensitivity to endotoxin-induced injury. Lipopolysaccharide (LPS) is recognized by toll-like receptor 4 (TLR4), whereas lipopeptide triggers TLR2 to induce common downstream activation of nuclear factor (NF)-kappaB and pro-inflammatory pathways that are activated in AFL and NAFL. METHODS: Serum alanine aminotransferase (ALT), tumor necrosis factor (TNF)-alpha, and interleukin (IL)-6 levels; hepatic NF-kappaB activity; and expression of TLR2, TLR4, inducible nitric oxide synthase (iNOS), and heme oxygenase (HO)-1 mRNAs were investigated in lean and leptin-deficient ob/ob mice after LPS challenge in combination with acute or chronic alcohol feeding. RESULTS: Increased LPS sensitivity in AFL and NAFL was characterized by elevated serum TNF-alpha and IL-6 induction. However, there was no difference in TLR2 and TLR4 mRNA levels between lean and ob/ob livers at baseline and after acute or chronic alcohol treatment. LPS increased TLR2, but not TLR4, mRNA levels in all groups. Chronic alcohol feeding and LPS increased serum ALT and TNF-alpha levels in lean but not in ob/ob mice compared with pair-fed controls. Hepatic NF-kappaB activation was increased in both ob/ob and lean mice after chronic alcohol feeding compared with pair-fed controls. Expression of iNOS, an inducer of oxidative stress, and HO-1, a cytoprotective protein, were higher in ob/ob compared with lean mice after chronic alcohol feeding. However, LPS-induced HO-1, but not iNOS, expression was attenuated in ob/ob compared with lean mice. CONCLUSION: These results imply that the increased sensitivity of AFL to LPS occurs without up-regulation of TLR2 or TLR4 genes and may be related to an imbalance of pro-inflammatory/oxidative and cytoprotective mechanisms.