【文献导读】 人体机能经过长期进化可以说已臻尽善尽美,竟然让很多人怀疑自己的身体是否上帝的“杰作”?不管你信不信,人体的绝大多数机能都是建立在对自身“有益无害”的原则之上,唯有免疫功能除外。为什么这么说呢?因为免疫系统在负责消灭“来犯之敌”的过程中无可避免地要“损兵折将”,这就像在战场上打仗一样,要打胜仗没有战士牺牲是不可能的。人体的免疫功能是一把名副其实的“双刃剑”,它有时对人体有益,有时又对人体有害。 免疫功能是通过体液免疫和细胞免疫来实现的,体液免疫通过抗原刺激B细胞产生抗体直接触发抗原-抗体结合反应并清除之,细胞免疫则通过刺激T细胞分泌细胞因子杀伤病原体。有人可能不知道细胞因子是怎样“杀敌”的,其实它们并不是正面“迎敌”。被抗原激活的T细胞释放促炎症细胞因子后,通过刺激巨噬细胞产生一氧化氮(NO)及各种活性氧(ROS)杀伤病原体,其效率之高令人惊叹!免疫细胞不仅要消灭“外敌”——病毒、细菌、真菌、寄生虫,而且还要清除“内鬼”——癌细胞。 原来,免疫功能的双重性正是源于NO的双重性。我们知道,短期接触NO或低浓度NO对身体无害或有益,长期接触NO或高浓度NO对身体无益或有害。从目前的观点来看,病原体长期感染引发的慢性炎症不仅是癌症的病因,而且也是衰老及衰老相关疾病(包括糖尿病、自身免疫病、心血管病、神经退行性疾病)的致病因素。最近,PLoS ONE上发表的一篇文章揭示了肠道慢性细菌感染在诱发类风湿性关节炎(RA)中的关键作用,初步肯定NO就是RA的致病因子。 用活细菌饲喂小鼠一个月后,其足与爪皆出现明显的红肿现象;关节切片显示滑膜细胞增生及淋巴细胞浸润;抗体芯片数据表明促炎症细胞因子INFγ、TNFα、IL-1β、IL-6普遍上调。同时,血液中NO含量升高,血氧饱和度下降,而且NO含量与血氧饱和度成反相关,说明NO爆发可能导致缺氧。缺氧的后果是有氧代谢减弱,无氧代谢增强,这可从乳酸含量升高体现出来。在基因表达水平上,缺氧通过诱导HIF-1α转录因子激活血管内皮生长因子(VEGF)导致血管增生和细胞增殖,而毛细血管的不断延伸又将促炎症细胞因子带到滑膜组织深处引起淋巴浸润。 为什么断定NO可引起缺氧而且是导致RA的肇因呢?将NO供体化合物——硝普钠(SNP)注射到小鼠关节腔,只需一天时间就能使小鼠关节出现红肿现象,而红肿部位的血氧饱和度也随之下降。因此,NO通过诱导缺氧引发RA,但真正的“元凶”是肠道细菌感染,NO只是充当发病的媒介。为此,用抗生素抗感染、雷帕霉素抑制免疫激活、青蒿琥酯抑制NO合成等方法进行处理,结果发现它们都能缓解或阻断RA的病情进展。 从以上研究结果可知,防治RA的最佳方法应该是抗感染,而当前的常规疗法都注重消炎,如抗TNFα 抗体是用来阻断促炎症细胞因子的广泛激活,显然属于“治标”未“治本”的疗法。另外,在包括873位RA患者和1004位健康志愿者的供试人群中发现,长期少量饮酒可以减少RA的发作或减低其严重程度(Maxwell JR et al.Alcohol consumption is inversely associated with risk and severity of rheumatoid arthritis. Rheumatology 42: 508-514)。我们推测这一结果可能来自低度酒精的消炎作用,而不是抗感染作用。 本研究仅涉及RA的早期——滑膜炎阶段,当滑膜炎进一步恶化将出现骨骼及软骨受损,经过损伤-修复-再损伤-再修复的病理循环,最终可导致关节畸形和运动功能丧失。我们相信,经过抗感染治疗的患者肯定不会发展到RA的终末阶段。至于在RA患者体内检测到的各种自身抗体,应当是RA致病的结果,而不是致病原因。随着感染的消除和炎症的终止,这些自身抗体也就会慢慢消失。因此,建议有RA患者的家庭应该尽快让患者看看传染科医生,找到患者体内的感染源和炎症发作部位(包括肺结核、前列腺炎、阴道炎、慢性肝炎等),并对症治疗,就会大大减轻RA病情甚至治愈。 该文为开放获取,点击链接下载: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0034494
《BMC免疫学》:醉酒会使免疫功能下降 一项最新研究显示,酩酊大醉带来的不仅是酒醒后的头痛,还有免疫系统功能下降,酒精对一些免疫功能的抑制会超过24小时。 美国科研人员在新一期英国《BMC免疫学》( BMC Immunology )杂志上报告说,他们检测了实验鼠在短时间内饮下大量酒精后其免疫系统所受影响。结果发现,酒精会抑制名为TLR4的蛋白质的作用,而这种蛋白质是许多有免疫作用的细胞因子的信号员,这些细胞因子被激活后会引发炎症等免疫反应,以帮助机体对抗细菌和病毒等。 实验显示,这些信号员在人醉酒后不能好好站岗,即便在醉酒24小时后,一些细胞因子仍然不能被激活。 研究人员因此提醒,大醉一场至少会带来24小时的免疫功能低下期,经常醉酒的人要警惕感染各种疾病的风险。 http://www.sciencenet.cn/htmlnews/2009/9/223536.shtm 更多阅读 物理学家组织网相关报道(英文) 《BMC免疫学》发表论文摘要(英文) http://www.biomedcentral.com/1471-2172/10/49/abstract Ethanol inhibits LPS-induced signaling and modulates cytokine production in peritoneal macrophages in vivo in a model for binge drinking Stephen B Pruett and Ruping Fan BMC Immunology 2009, 10:49 doi:10.1186/1471-2172-10-49 Published: 18September2009 Abstract (provisional) Background Previous reports indicate that ethanol, in a binge drinking model in mice, inhibits the production of pro-inflammatory cytokines in vivo. However, the inhibition of signaling through TLR4 has not been investigated in this experimental model in vivo. Considering evidence that signaling can be very different in vitro and in vivo, the present study was conducted to determine if effects of ethanol on TLR4 signaling reported for cells in culture or cells removed from ethanol treated mice and stimulated in culture also occur when ethanol treatment and TLR4 activation occur in vivo. Results Phosphorylated p38, ERK, and c-Jun (nuclear) were quantified with kits or by western blot using samples taken 15, 30, and 60 min after stimulation of peritoneal macrophages with lipopolysaccharide in vivo. Effects of ethanol were assessed by administering ethanol by gavage at 6 g/kg 30 min before administration of lipopolysaccharide (LPS). Cytokine concentrations in the samples of peritoneal lavage fluid and in serum were determined at 1, 2, and 6 hr after lipopolysaccharide administration. All of these data were used to measure the area under the concentration vs time curve, which provided an indication of the overall effects of ethanol in this system. Ethanol suppressed production of most pro-inflammatory cytokines to a similar degree as it inhibited key TLR4 signaling events. However, NF-kappaB (p65) translocation to the nucleus was not inhibited by ethanol. To determine if NF-kappaB composed of other subunits was inhibited, transgenic mice with a luciferase reporter were used. This revealed a reproducible inhibition of NF-kappaB activity, which is consistent with the observed inhibition of cytokines whose expression is known to be NF-kappaB dependent. Conclusions Overall, the effects of ethanol on signalling in vivo were similar to those reported for in vivo exposure to ethanol and/or lipopolysaccharide. However, inhibition of the activation of NF-kappaB was not detected as translocation of p65 to the nucleus but was detected using transgenic reporter mice. The observation that ethanol given 24 hr before dosing with LPS modulated production of some cytokines indicates a persistent effect which does not require continued presence of ethanol. 信息分析平台: http://www.gopubmed.org/web/gopubmed/WEB1mOWEB10O00d000j10020001000d000j100300.y 检索策略:TLR4 and drinking 相关文献计量分析结果: Top Years Publications 2008 6 2007 3 2004 3 2009 2 2006 1 2005 1 2001 1 Top Countries Publications USA 7 Japan 3 Israel 3 Canada 1 Taiwan 1 South Korea 1 France 1 Top Cities Publications Shreveport 2 Haifa 2 Osaka 1 Kyoto 1 Toronto 1 Cleveland 1 Taipei 1 Anyang, South Korea 1 Lille 1 Worcester 1 Boston 1 Sapporo 1 Urbana 1 Bethesda 1 Top Journals Publications Clin Exp Immunol 3 Am J Physiol Gastrointest Liver Physiol 1 J Gastroenterol Hepatol 1 J Immunotoxicol 1 Am J Reprod Immunol 1 Methods Mol Biol 1 Shock 1 Digest Dis Sci 1 Med Mycol 1 Pancreatology 1 Infect Immun 1 Alcohol 1 Physiol Behav 1 Gastroenterology 1 Alcohol Clin Exp Res 1 1 2 3 4 5 Top Authors Publications Pruett S 2 Sukhotnik I 2 Mogilner J 2 Lurie M 2 Takeda K 2 Akira S 2 Arakawa T 1 Watanabe T 1 Nishio H 1 Tanigawa T 1 Yamagami H 1 Okazaki H 1 Watanabe K 1 Tominaga K 1 Fujiwara Y 1 Oshitani N 1 Asahara T 1 Nomoto K 1 Higuchi K 1 Takeuchi K 1 1 2 3 4 5 1 2 3 ... 22 Top Terms Publications tlr4 14 Animals 14 Mice 12 Toll-Like Receptor 4 11 Toll-Like Receptors 11 Tumor Necrosis Factor-alpha 8 Lipopolysaccharides 8 tlr 7 Cytokines 7 Macrophages 7 gut development 6 RNA, Messenger 6 Proteins 6 Intestines 6 Wounds and Injuries 5 Necrosis 5 Evaluation Studies as Topic 5 signal transduction 5 programmed cell death 5 Monocytes 5 1 2 3 ... 22 相关研究报道: Title: Probiotic Lactobacillus casei strain Shirota prevents indomethacin-induced small intestinal injury: involvement of lactic acid. PMID: 19589943 Related Articles Authors: Watanabe, T , et.al. Journal: Am J Physiol Gastrointest Liver Physiol , Vol. 297 (3): G506-13 , 2009 Snippet: One-week treatment with viable LcS prevented indomethacin-induced intestinal injury with increase in the concentration of lactic acid in small intestinal content and inhibited increases in myeloperoxidase activity and expression of mRNA for tumor necrosis factor-alpha ( TNF-alpha ) while affecting neither TLR4 expression nor the number of gram-negative bacteria in intestinal content, whereas neither heat-killed LcS nor a single dose of viable LcS inhibited intestinal injury. Affiliation: Dept. of Gastroenterology, Osaka City Univ. Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan . watanabet@med.osaka-cu.ac.jp Title: Isoflavones regulate innate immunity and inhibit experimental colitis. PMID: 19220665 Related Articles Authors: Morimoto, M , et.al. Journal: J Gastroenterol Hepatol , Vol. 24 (6): 1123-9 , 2009 Snippet: METHODS: We administered daidzein-rich isoflavone aglycones (DRIA) to mice for 1 week and then treated them with 2% dextran sodium sulfate (DSS) in drinking water for 4 days to induce colitis. Affiliation: Department of Clinical Bio-regulatory Science, Kyoto University Graduate School of Medicine, Kyoto , Japan . Title: Different Effects of Acute and Chronic Ethanol on LPS-Induced Cytokine Production and TLR4 Receptor Behavior in Mouse Peritoneal Macrophages. PMID: 18958703 Related Articles Authors: Dai, Q , et.al. Journal: J Immunotoxicol , Vol. 3 (4): 217-25 , 2006 Snippet: Both binge and chronic heavy drinking can adversely affect the immune system, but the effects seem to be at least partly dependent on the manner of ethanol (EtOH) consumption. Affiliation: Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport , LA , USA . Title: LPS -induced murine abortions require C5 but not C3 , and are prevented by upregulating expression of the CD200 tolerance signaling molecule. PMID: 18705840 Related Articles Authors: Yu, G , et.al. Journal: Am J Reprod Immunol , Vol. 60 (2): 135-40 , 2008 Snippet: PROBLEM: Lipopolysaccharide (LPS) acts via tlr4 to promote Th1 cytokine secretion and abortions. Affiliation: Toronto General Research Institute CIHR Group on Cellular and Molecular Mechanisms of Organ Injury, Institute of Medical Sciences, University of Toronto, Toronto , Ontario , Canada . Title: Isolation of Kupffer cells from rats fed chronic ethanol. PMID: 18369921 Related Articles Authors: McMullen, M R , et.al. Journal: Methods Mol Biol , Vol. 447 , 2008 Snippet: Activation of Kupffer cells leads to an increased production of proinflammatory cytokines, such as tumor necrosis factor-alpha and also reactive oxygen species, a process mediated in part by changes in lipopolysaccharide-induced TLR4 -dependent signal transduction. Affiliation: Department Pathobiology, Cleveland Clinic, Cleveland , OH , USA . Title: TLR ligand decreases mesenteric ischemia and reperfusion injury-induced gut damage through TNF-alpha signaling. PMID: 18317407 Related Articles Authors: Chen, L , et.al. Journal: Shock , Vol. 30 (5): 563-70 , 2008 Snippet: We hypothesize that LPS, a ligand for TLR4 , decreases mesenteric I/R injury-induced gut damage through tumor necrosis factor alpha ( TNF-alpha ) signaling. Affiliation: Institute of Emergency and Critical Care Medicine, National Yang-Ming University, Taipei . chenlw2001@yahoo.com.tw Title: Treatment with glutamine is associated with down-regulation of Toll-like receptor-4 and myeloid differentiation factor 88 expression and decrease in intestinal mucosal injury caused by lipopolysaccharide endotoxaemia in a rat. PMID: 18070149 Related Articles Authors: Kessel, A , et.al. Journal: Clin Exp Immunol , Vol. 151 (2): 341-7 , 2008 Snippet: For this purpose, male Sprague-Dawley rats were assigned randomly to one of three experimental groups of 10 rats each: (i) control rats underwent intraperitoneal (i.p.) injection of sterile saline once a day; (ii) rats were treated with LPS given i.p. once a day at a dose of 10 mg/kg for 48 h (two doses); and (iii) rats were pretreated with oral Gln given in drinking water (2%) 48 h before and following injection of LPS. Affiliation: Allergy and Clinical Immunology, Bnai Zion Medical Center, The Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa , Israel . aharon.kessel@b-zion.org.il Title: Lactobacillus casei prevents the development of dextran sulphate sodium-induced colitis in Toll-like receptor 4 mutant mice. PMID: 18005362 Related Articles Authors: Chung, Y W , et.al. Journal: Clin Exp Immunol , Vol. 151 (1): 182-9 , 2008 Snippet: TLR -4(lps-/lps-) and wild-type (WT) mice were given 2.5% dextran sulphate sodium (DSS) in drinking water to induce colitis with or without Lactobacillus casei pretreatment. Affiliation: Department of Gastroenterology, Hallym University Sacred Heart Hospital, Anyang , Korea . Title: Oral insulin up-regulates Toll-like receptor 4 expression and enhances intestinal recovery following lipopolysaccharide-induced gut injury in a rat. PMID: 17934814 Related Articles Authors: Sukhotnik, I , et.al. Journal: Dig Dis Sci , Vol. 53 (5): 1231-9 , 2008 Snippet: Male Sprague-Dawley rats were divided into three experimental groups: Sham rats, LPS-rats that were treated with lipopolysaccharide (LPS), and LPS-INS rats that were treated with OI given in drinking water 72 h before and following injection of LPS. Affiliation: Department of Pediatric Surgery B, Bnai Zion Medical Center, Haifa , Israel . igor-dr@internet-zahav.net Title: Saccharomyces boulardii decreases inflammation and intestinal colonization by Candida albicans in a mouse model of chemically-induced colitis. PMID: 17885943 Related Articles Authors: Jawhara, S , et.al. Journal: Med Mycol , Vol. 45 (8): 691-700 , 2007 Snippet: A 1.5% solution of DSS was administered in drinking water 1 h after C. albicans oral challenge, while 10(7) cells of S. boulardii was inoculated daily by oral gavage for 1 week. Affiliation: Inserm U 799, Physiopathologie des Candidoses, Facult de Mdecine, CHRU Lille , France . Effect of ethanol on inflammatory responses. Implications for pancreatitis. PMID: 17592223 Related Articles Authors: Szab, G , et.al. Journal: Pancreatology , Vol. 7 (2-3): 115-23 , 2007 Snippet: In contrast, acute alcohol treatment augmented NF -kappaB activation and TNFalpha production and inhibited IL-10 levels in the presence of complex stimulation with combined TLR2 and TLR4 ligands. Affiliation: Department of Medicine, University of Massachusetts Medical School, Worcester , Massachusetts , USA . gyongyi.szabo@umassmed.edu Title: Resistance to Pseudomonas aeruginosa chronic lung infection requires cystic fibrosis transmembrane conductance regulator-modulated interleukin-1 ( IL-1 ) release and signaling through the IL-1 receptor . PMID: 17283089 Related Articles Authors: Reiniger, N , et.al. Journal: Infect Immun , Vol. 75 (4): 1598-608 , 2007 Snippet: We found neither Toll-like receptor 2 ( TLR2 ) nor TLR4 nor TLR5 were required for this response. Affiliation: Channing Laboratory, Brigham and Women's Hospital, Harvard Medical School, 181 Longwood Avenue, Boston , MA 02115, USA . Title: Macrophage migration inhibitory factor contributes to the development of acute dextran sulphate sodium-induced colitis in Toll-like receptor 4 knockout mice. PMID: 16045730 Related Articles Authors: Ohkawara, T , et.al. Journal: Clin Exp Immunol , Vol. 141 (3): 412-21 , 2005 Snippet: TLR4 (-/-) mice were given 2% dextran sulphate sodium (DSS) in drinking water to induce colitis, which was clinically and histologically as severe as that seen in wild-type (WT) mice. Affiliation: Department of Gastroenterology and Hematology, Hokkaido University Graduate School of Medicine, Sapporo , Japan . tokawara@med.hokudai.ac.jp Title: Ethanol suppresses cytokine responses induced through Toll -like receptors as well as innate resistance to Escherichia coli in a mouse model for binge drinking . PMID: 15528012 Related Articles Authors: Pruett, S B , et.al. Journal: Alcohol , Vol. 33 (2): 147-55 , 2004 Snippet: It has been reported that acute administration of ethanol suppresses responses mediated through TLR3 and TLR4 . Affiliation: Department of Cellular Biology and Anatomy, LSU Health Sciences Center, 1501 Kings Highway, Shreveport , LA 71130, USA . spruet@LSUHSC.edu Title: Dehydroepiandrosterone-sulfate did not mitigate sickness behavior in mice. PMID: 15327921 Related Articles Authors: Chen, J , et.al. Journal: Physiol Behav , Vol. 82 (4): 713-9 , 2004 Snippet: Mice were provided drinking water with 0% or 0.01% DHEA-S for 2 weeks and then injected intraperitoneally with saline or LPS (1 microg). Affiliation: Division of Nutritional Sciences, Department of Animal Sciences, University of Illinois, 1207 West Gregory Drive, Urbana , IL 61801, USA . Title: Toll-like receptor 9 signaling mediates the anti-inflammatory effects of probiotics in murine experimental colitis. PMID: 14762789 Related Articles Authors: Rachmilewitz, D , et.al. Journal: Gastroenterology , Vol. 126 (2): 520-8 , 2004 Snippet: Viable or gamma-irradiated probiotics were administered i.g. to wild-type mice and mice deficient in different TLR or in the adaptor protein MyD88, 10 days prior to administration of dextran sodium sulfate (DSS) to their drinking water and for 7 days thereafter. Affiliation: Division of Medicine, Shaare Zedak Medical Center, Jerusalem, Israel . Title: Pro- and anti-inflammatory gene expression in the murine small intestine and liver after chronic exposure to alcohol . PMID: 11329499 Related Articles Authors: Fleming, S D , et.al. Journal: Alcohol Clin Exp Res , Vol. 25 (4): 579-89 , 2001 Snippet: In the current study, we hypothesized that alcohol would alter cytokine expression within the small intestine of mice exposed to ethanol and that LPS would alter levels of cytokine expression even more dramatically. Affiliation: Department of Microbiology, Uniformed Services University of the Health Sciences, Bethesda , MD 20814, USA .