小剂量羟乙基淀粉对脓毒症大鼠的肺保护作用研究

目的研究小剂量羟乙基淀粉130/0.4(HES)对脓毒症模型大鼠肺毛细血管通透性以及全身及局部炎症细胞因子水平的影响。方法 40只雄性SD大鼠,随机分为小剂量组(S组)、大剂量组(L组)、脓毒症对照组(SC组)及假手术对照组(C组)4组,每组10只。S组、L组及SC组均采用盲肠结扎穿孔的方法建立脓毒症大鼠模型;分别于CLP后4h时静脉输注HES 5ml/kg+生理盐水25ml/kg、HES 30ml/kg,SC组于相应时点输注生理盐水30ml/kg。CLP后6h处死大鼠,取肺组织计算含水量,测定毛细血管通透性、炎症细胞因子肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)水平及外周血炎症细胞因子水平。结果与C组比较,S组、L组及SC组肺含水量、毛细血管通透性均明显增高,肺组织及外周血TNF-α、IL-1β、IL-6水平增高(P0.05)。与SC组比较,S组与L组肺含水量、毛细血管通透性均有降低,肺组织及外周血TNF-α、IL-1β、IL-6水平降低(P0.05);与S组比较,L组TNF-α、IL-1β、IL-6水平有所降低,但无统计学差异。结论小剂量羟乙基淀粉130/0.4具有一定肺保护作用。     

栀子苷元通过抑制内质网应激改善脾细胞凋亡治疗脓毒症的机制研究

目的 评估栀子苷元 (Genipin) 对盲肠结扎穿孔术 (Cecal Ligation and Puncture,CLP) 诱导的脓毒症小鼠模型的治疗效果,并探讨其潜在的作用机制。方法 将雄性 C57BL/6 小鼠分为假手术组 (Sham组)、脓毒症模型组 (CLP组)、栀子苷元治疗脓毒症组 (Genipin+CLP组)。栀子苷元治疗组在建模后0 h和20 h经尾静脉注射2.5 mg/kg栀子苷元,而Sham组和CLP组注射等体积生理盐水。实验1,观察栀子苷元对脓毒症小鼠120 h生存率的影响;实验2,基于生存率的结果选取建模后36 h为采样时间点,并行以下方法检测：利用酶联免疫吸附法 (Enzym-linked Immunosorbent Assay,ELISA) 检测肿瘤坏死因子α (Tumor Necrosis Factor α,TNF-α) 和白细胞介素6(Interleukin 6,IL-6) 含量;常规苏木精-伊红 (Hematoxylineosin,HE) 染色法检测肺和肝组织病理损害;Western Blot法检测脾脏内质网应激相关蛋白的表达变化,包括葡萄糖调节蛋白 78 (Glucose Regulated Protein 78,GRP78)、蛋白激酶 R 样内质网激酶 (Protein Kinase R-like Endoplasmic Reticulum Ki‐ nase,PERK)、磷酸化真核翻译起始因子2α (p-eukaryotic Initation Factor 2α,p-eIF2α) 和C/EBP同源蛋白 (C/EBP Homolo‐ gous Protein,CHOP);脱氧核糖核苷酸末端转移酶介导的缺口末端标记法 (Terminal-deoxynucleotidyl Transferase-mediated dUTP Nick End-labeling,TUNEL) 检测脾细胞凋亡变化。结果 与 CLP组相比,栀子苷元治疗提高了脓毒症小鼠 120 h生存率 (P＜0.05),降低了血清 TNF-α和 IL-6含量 (P＜0.05),并减轻肺和肝脏组织病理学损伤。另外,栀子苷元显著下调了脾脏GRP78、PERK、p-eIF2α和CHOP蛋白的表达水平 (P＜0.05),并进而减少内质网应激诱导的脾细胞凋亡数量 (P＜0.05)。 结论 栀子苷元能够明显减轻脓毒症所导致的脏器损害和过度炎症反应,改善脓毒症预后。该效应的作用机制可能与栀子苷元减轻脾脏内质网应激导致其凋亡机制的启动被阻断,进而减轻脾细胞凋亡有关。     

胶原诱导的关节炎小鼠脾脏单个核细胞TLR8的表达及其与相关细胞因子的关系

目的:观察Toll样受体8(TLR8)在鸡Ⅱ型胶原诱导的关节炎模型小鼠脾脏单个核细胞中的表达及其与IL-10等细胞因子表达的关系.方法:12只DBA/1J小鼠随机分成造模组和阴性对照组.造模组小鼠采用鸡Ⅱ型胶原诱导,在诱导后的第27天出现关节红肿时处死所有小鼠.用ELISA测定小鼠外周血的TNF-α,HE染色观察小鼠关节的炎症变化,Real-time PCR检测脾脏单个核细胞表达IL-10、IL-17A、IL-1β及TLR8的水平.结果:HE染色结果显示,造模组小鼠关节部位与阴性对照组相比出现明显的炎症细胞浸润;造模组小鼠的外周血血清TNF-α水平较阴性对照组明显升高(P< 0.01);模型小鼠脾脏单个核细胞表达IL-10、IL-17A、TLR8和IL-1β的水平也明显高于阴性对照组(P<0.01或P<0.05).相关性分析表明,TLR8的表达与IL-10的表达呈负相关(r=0.945;P<0.01),而与IL-17A、IL-1β无明显相关性(P>0.05).结论:TLR8在鸡Ⅱ型胶原诱导的关节炎模型小鼠脾脏单个核细胞中的表达水平明显升高.尽管IL-10的表达水平也高于对照组,但其与TLR8的表达呈现明显负相关.     

菊粉增加非酒精性脂肪肝病小鼠外周血、肝脏及脾脏单核细胞型髓源性抑制细胞比例并调节炎症因子的分泌

目的探讨菊粉(INU)对非酒精性脂肪肝病(NAFLD)小鼠单核细胞型髓源性抑制细胞(M-MDSC)和血浆炎症因子的影响。方法 C57BL/6小鼠随机分为正常饮食组、 INU对照组、 NAFLD模型组和INU处理的NAFLD模型组。正常饮食组和INU对照组给予普通饲料,NAFLD模型组和INU处理的NAFLD模型组给予高脂饲料(含60%脂肪)。同时INU对照组和INU处理的NAFLD模型组给予INU(5 g/kg),喂养14周后,处死小鼠并收集小鼠外周血、肝脏和脾脏细胞。采用流式细胞术检测外周血、肝脏和脾脏中M-MDSC比例。细胞因子流式微球阵列检测技术(CBA)检测血浆中肿瘤坏死因子α(TNF-α)和白细胞介素10(IL-10)表达水平。Pearson统计分析各组织M-MDSC比例和血浆炎症因子水平的相关性。结果与正常饮食组相比,NAFLD模型组外周血、肝脏和脾脏中M-MDSC的比例明显增加,血浆中TNF-α水平显著升高,IL-10水平变化不明显。与NAFLD模型组相比,INU处理的NAFLD模型组外周血、肝脏和脾脏中M-MDSC的比例明显增加,TNF-α水平显著降低、 IL-10水平显著升高。NAFLD小鼠外周血、肝脏及脾脏中M-MDSC分别与TNF-α呈负相关,与IL-10呈正相关。结论 INU可募集NAFLD小鼠外周血、肝脏及脾脏中M-MDSC,发挥抗炎作用,延缓NAFLD的发生发展。     

PD-L1阻断对脓毒症小鼠T淋巴细胞凋亡及单核细胞功能的影响北大核心CSCD

目的:探讨程序性死亡受体-1配体(PD-L1)阻断对脓毒症小鼠T淋巴细胞凋亡及单核细胞功能的影响。方法:30只8~10周龄清洁级C57BL/6雄性小鼠随机分为3组:sham组、模型组、PD-L1拮抗组,每组10只,模型组、PD-L1拮抗组小鼠采用盲肠结扎穿孔手术(CLP)构建脓毒症小鼠模型,sham组小鼠暴露盲肠后即进行伤口缝合,不结扎。PD-L1拮抗组小鼠术后腹腔注射抗PD-L1抗体(50μg/只),每6 h注射1次,连续4次,sham组和模型组小鼠腹腔注射等剂量生理盐水。流式标记法检测各组小鼠CD3+T细胞表面PD-1和单核细胞CD11b+表面PD-L1表达,HE染色观察组织病理学改变,电镜下观察脾脏和胸腺超微病理结构改变,TUNEL染色检测脾脏和胸腺组织细胞凋亡、流式细胞术检测胸腺组织T淋巴细胞凋亡,ELISA检测Caspase-3和TNF-α、IL-6及IL-10表达。结果:与sham组相比,模型组小鼠CD3^(+)、CD11b^(+)表面PD-1和PD-L1表达、脾脏和胸腺组织细胞凋亡率、T淋巴细胞凋亡率、Caspase-3、TNF-α、IL-6、IL-10蛋白表达显著升高(P<0.05);与模型组相比,PD-L1拮抗组小鼠CD3^(+)、CD11b^(+)表面PD-1和PD-L1表达、脾脏和胸腺组织细胞凋亡率、T淋巴细胞凋亡率、Caspase-3、TNF-α、IL-6蛋白表达明显降低,IL-10表达明显升高(P<0.05)。结论:PD-L1阻断可有效降低脓毒症小鼠T细胞凋亡率,改善其单核细胞功能。     

ITP患者脾切除前后外周血Th亚群细胞因子的变化及意义

目的: 探讨辅助性T淋巴细胞(T helper lymphocyte,Th)亚群细胞因子在原发性免疫性血小板减少症(ITP)患者脾切除术前后的表达及意义。方法: 采用QuantiGene Plex (QGP)方法检测22例ITP患者腹腔镜脾切除术前后外周血Th1(IL-2和IFN-γ)、Th2(IL-4、IL-5、IL-6和IL-10)、Th3(TGF-β₁)和Th17(IL-17)细胞因子mRNA表达水平的变化。30例健康体检者作为对照组。结果: (1)术前组IL-2表达水平较对照组明显降低(P<0.05),IL-17表达水平较对照组明显升高(P<0.05),其它细胞因子表达水平在术前组和对照组之间无显著差异(P>0.05)。术后组TGF-β₁表达较术前组和正常对照组均明显升高(P<0.05);术后组IL-2 表达较术前有所升高(P<0.05),但仍低于对照组(P<0.05)。其它细胞因子表达水平在术前组和术后组之间无显著性差异(P>0.05)。(2)术前IL-2与IFN-γ之间成正相关(r=0.647,P<0.01),术前其它细胞因子之间均无明显相关性(P>0.05)。术后3对细胞因子之间成正相关,分别是IL-2与IFN-γ(r=0.787, P<0.01),IL-17与IL-2(r=0.554,P<0.01),IL-17与IFN-γ(r=0.461,P<0.05);术后其它细胞因子之间均无明显相关性(P>0.05)。 结论: ITP患者存在Th亚群细胞因子失衡,脾切除术可改善ITP患者部分Th亚群细胞因子的失衡。     

亚麻籽油对动脉粥样硬化ApoE~(-/-)小鼠M-MDSC及炎症因子的影响

目的分析富含α-亚麻酸(α-linolenic acid,ALA)的亚麻籽油(flaxseed oil,FO)干预动脉粥样硬化症(atherosclerosis,AS)ApoE~(-/-)小鼠髓源抑制性细胞(myeloid-derived suppressor cells,MDSCs)中单核细胞样MDSCs(M-MDSCs)比例的变化,检测血浆和主动脉炎症因子及其与M-MDSCs的相关性。方法将30只雄性ApoE~(-/-)小鼠随机分为3组(10只/组):空白对照组(CON)、AS模型组(MOD)和亚麻籽油干预组(MOD/FO)。干预10周后,采用流式细胞术检测外周血和脾脏中M-MDSCs含量,采用流式微球阵列检测技术(CBA)检测血浆及主动脉组织肿瘤坏死因子(tumor necrosis factor,TNF)-α、白细胞介素(interleukin,IL)-1β、IL-6和IL-10的水平;采用Pearson方法分析M-MDSCs与炎症因子的相关性。结果 FO干预后的AS斑块减轻(P0.05),且外周血和脾脏M-MDSCs比例显著高于MOD组(P0.05);此外,外周血IL-1β和TNF-α水平较MOD组显著降低,主动脉组织TNF-α、IL-1β和IL-6水平较MOD组均显著降低(P均0.05),IL-10虽有升高,但无统计学差异。相关性分析发现外周血MMDSCs与主动脉组织TNF-α、IL-1β、IL-6呈负相关,与主动脉组织IL-10呈正相关,并与血浆TNF-α、IL-1β呈负相关。结论富含ALA的FO能够升高AS小鼠M-MDSCs比例并抑制炎症。     

疏肝健脾方对NASH大鼠肝组织IKKβmRNA和蛋白表达的影响

目的:探讨疏肝健脾方对非酒精性脂肪性肝炎(NASH)大鼠肝组织核因子κB(NF-κB)抑制蛋白激酶β(IKKβ)mRNA和蛋白表达的影响。方法:采用高脂饲料喂养建立NASH大鼠实验模型,在施以造模因素的同时各药物干预组大鼠分别灌服疏肝方(柴胡疏肝散)、健脾方(参苓白术散)和综合方(柴胡疏肝散和参苓白术散的合方)的高、低剂量进行干预,16周后各组大鼠腹主动脉采血,全自动生化分析仪检测血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)及肝组织TC、TG的含量;ELISA检测血清肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)及白细胞介素1(IL-1)的水平;HE染色观察肝组织病理变化;实时荧光定量RT-PCR检测肝组织IKKβmRNA的表达水平;Westernblotting检测肝组织IKKβ蛋白磷酸化水平的变化。结果:肝组织病理染色提示大鼠NASH造模成功,与正常组比较,模型组大鼠血清TC、LDL-C、肝组织TC、TG及炎症细胞因子TNF-α、IL-1、IL-6水平均显著升高(P<0.01,P<0.05),肝组织IKKβmRNA及其磷酸化蛋白的表达水平均明显升高(P<0.01)。与模型组相比,肝组织TC、TG含量及血清TNF-α的含量以综合方高、低剂量组、健脾方高剂量组及疏肝方高剂量组下降显著(P<0.01,P<0.05);IL-1和IL-6含量均以综合方高剂量组降低显著(P<0.05),IKKβmRNA的表达水平以综合方高组及健脾方高组下调明显(P<0.05),磷酸化IKKβ蛋白的表达水平以健脾方高剂量组及综合方高、低剂量组下降最为显著(P<0.01,P<0.05)。结论:血清炎症细胞因子TNF-α、IL-1和IL-6水平的显著升高、肝组织IKKβmRNA及其磷酸化蛋白的高表达可能参与NASH的发病。降低相关炎症细胞因子的含量、抑制IKKβmRNA及蛋白磷酸化可能是疏肝健脾方抗NASH的重要机制之一。     

菊粉对多囊卵巢综合征小鼠外周血、脾脏、肝脏髓源抑制性细胞及血浆炎症因子的影响

目的分析菊粉对多囊卵巢综合征(polycystic ovary syndrome,PCOS)小鼠髓源抑制性细胞(myeloid-derived suppressor cells,MDSCs)、单核细胞样MDSCs(monocytic-MDSCs,M-MDSCs)比例的变化和意义及其与血浆炎症因子的相关关系。方法采用60%高脂饮食联合颈背部皮下注射脱氢表雄酮6 mg/100 g+0.1 ml芝麻油制备PCOS小鼠模型,选取21～27日龄的雌性C57BL/6J小鼠30只,随机分为正常对照组、模型组、菊粉干预组,每组10只。流式细胞仪检测各组小鼠外周血、脾脏、肝脏中MDSCs和M-MDSCs的比例变化以及炎症因子TNF-α、IL-17A和IL-10的水平。结果对MDSCs和M-MDSCs分析发现:与正常对照组小鼠相比,模型组小鼠外周血、脾脏、肝脏中MDSCs和M-MDSCs显著增加,与模型组小鼠相比,菊粉干预组小鼠外周血、脾脏和肝脏MDSCs及M-MDSCs也显著增加。对血浆炎症因子分析发现:TNF-α、IL-17A在模型组与正常对照组小鼠中相比显著增加,而在模型组与菊粉干预组中相比显著降低,IL-10在模型组与正常对照组小鼠中相比显著降低,而在模型组与菊粉干预组中相比增加,但是没有统计学意义。对MDSCs和M-MDSCs与血浆炎症因子TNF-α, IL-17A相关性分析发现:PCOS小鼠外周血、脾脏、肝脏中MDSCs和M-MDSCs与血浆炎症因子TNF-α、IL-17A均呈负相关。结论菊粉能够诱导MDSCs、M-MDSCs在外周血、脾脏和肝脏中募集,减少促炎因子TNF-α、IL-17A的生成,从而延缓疾病的进展。     

钩藤碱降低内毒素血症小鼠死亡率的机制研究

目的： 观察钩藤碱对内毒素血症小鼠死亡率及器宫损伤的影响，并探讨其作用机制。方法: 雄性小鼠随机分为对照组、脂多糖（LPS）组、钩藤碱（Rhy）防治组和Rhy对照组，分别予以生理盐水、Rhy皮下注射，1 time/d，连续3 d，第3 d皮下注射后1 h，腹腔注射生理盐水或LPS（20 mg/kg）。观察各组小鼠的死亡率，肺、小肠组织病理改变；测定注射LPS后12 h各组肺湿/干重比值 (W/D)及血清丙氨酸氨基转移酶（ALT）、门冬氨酸氨基转移酶（AST）、尿素氮（BUN）和肌酐（Cr）的水平；用酶联免疫吸附法（ELISA）测定血清肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）及白细胞介素-10（IL-10）的含量，用硝酸还原酶法试剂盒测定血清一氧化氮（NO）的含量。进一步复制盲肠结扎穿孔的脓毒症模型， 观察钩藤碱对脓毒症小鼠生存率的影响。结果: LPS攻击后24 h小鼠的生存率明显低于对照组，8、16 mg/kg的钩藤碱防治组小鼠生存率高于LPS组。但钩藤碱并不能降低CLP小鼠的死亡率，而且，8 mg/kg钩藤碱治疗组小鼠的死亡率反而高于CLP小鼠的死亡率。LPS攻击后12 h病理检查发现LPS组小鼠肺及小肠组织均有严重的炎症表现；肺W/D、血清ALT、AST、BUN、Cr水平显著高于对照组；LPS攻击后2 h血清TNF-α、IL-1β及IL-10含量及8 h血清NO水平显著高于对照组。LPS攻击后12 h， Rhy防治组肺及小肠组织损伤无明显改善；肺W/D、血清ALT、AST、BUN、Cr水平与LPS组比较无显著差异；LPS攻击后2 h血清TNF-α水平显著低于LPS组，但2 h血清IL-1β及IL-10含量及8 h血清NO水平与LPS组比较无显著差异。结论: 钩藤碱能降低内毒素血症小鼠的死亡率，但不能降低脓毒症小鼠的死亡率，抑制TNF-α的生成可能是钩藤碱降低内毒素血症小鼠死亡率的机制之一。     

Modulation of inflammatory response in sepsis by proteasome inhibition

The Ubiquitin-proteasome system has recently been shown to be involved in the regulation of cytokine expression. We tested the hypothesis of whether the in vivo administration of proteasome inhibitor MG-132 can modulate cytokine response and mortality in sepsis. Sepsis was induced in mice by caecal ligation and puncture (CLP). Animals were divided into four groups: control, CLP, CLP and 1 microg MG-132/g of b.w. intraperitoneally, and CLP and 10 microg MG-132/g of b.w. Plasma levels of interleukin (IL)-1, tumour necrosis factor-alpha (TNF-alpha, IL-6 and IL-10 were determined by ELISA 6 h after the induction of sepsis. CLP induced significant increase in plasma levels of all measured cytokines. MG-132 treatment resulted in lower increase in IL-1, TNF-alpha and IL-10 levels. IL-6 was not significantly affected. A mortality study revealed prolonged survival in MG-132 treated mice. We conclude that MG-132 treatment decreases inflammatory response and prolongs survival in the CLP model of sepsis.     

Effects of simvastatin on the function of splenic CD4<Superscript>+</Superscript> and CD8<Superscript>+</Superscript> T cells in sepsis mice

Simvastatin may be beneficial for treating sepsis due to its immune-regulating properties, although the mechanisms remain elusive. Herein, we hypothesized simvastatin may attenuate T cell dysfunction induced by sepsis. To test this hypothesis, we used a model based on cecal ligation and puncture (CLP) to induce sepsis in mice. Male C57BL/6 mice were pre-treated with simvastatin (0.2 μg/g of body weight) before CLP. The expression of B and T lymphocyte attenuator (BTLA) on splenic CD4⁺ T cells and T cell apoptosis, CD4⁺ and CD8⁺ T cells were quantified by flow cytometry. Immunohistochemical staining was performed to evaluate the loss of immune effector cells. Formation of TNF-α and interleukin 10 (IL-10) in the spleen and plasma levels of presepsin, IL-1β, and IL-6 were determined using enzyme-linked immunosorbent assay. Simvastatin markedly inhibited the reduction in cytokine secretion from lipopolysaccharide (LPS)-stimulated splenocytes. Simvastatin-treated mice had significantly decreased the percentages of negative costimulatory receptor BTLA on CD4 T cell expression. Simvastatin markedly reduced T cell apoptosis through downregulating the Fas/FasL expression and decrease the percentage of caspase-3 activity in spleen tissue. There was significantly less depletion of splenic CD4⁺ and CD8⁺ T cells in simvastatin-treated mice. Simvastatin reduced plasma levels of presepsin, IL-1β, and IL-6. Simvastatin can be a powerful regulator of immune function under sepsis conditions by improving T cell function in sepsis.     

Increased inflammation and lethality of Dusp1−/− mice in polymicrobial peritonitis models

The mitogen-activated protein kinase phosphatase Dusp1 (also known as MKP-1) is essential for control of the inflammatory response to systemic challenge with the lipopolysaccharide of Gram-negative bacteria. Here, we have investigated the consequences of Dusp1-deficiency in colon ascendens stent peritonitis (CASP) and caecal ligation and puncture (CLP), two mouse models of septic peritonitis. Following CASP, Dusp1^−/− mice had increased serum levels of CCL4, interleukin-10 (IL-10) and IL-6, with differences from wild-type mice being dependent on severity of sepsis. These cytokines, along with inducible nitric oxide synthase messenger RNA, were also expressed at higher levels in spleen and liver. Similar over-production of these cytokines was detected in the CLP model, with even larger differences from wild-type mice. Despite the increased inflammatory response, bacterial clearance was impaired in Dusp1^−/− mice subjected to CASP and CLP. Dusp1^−/− mice suffered increased lethality in both peritonitis models. Together our data indicate that exaggerated inflammatory responses to gut bacteria introduced into the peritoneum in the absence of Dusp1 do not help to control bacterial replication but are detrimental for the host.     

Interleukin-10 controls the onset of irreversible septic shock

Lethality from sepsis is believed to be mediated by a proinflammatory cytokine cascade, yet blocking the proinflammatory cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin-1 (IL-1) fails to prevent mortality in human disease and a mouse model of sepsis induced by cecal ligation and puncture (CLP). The role of the antiinflammatory cytokine IL-10 in the CLP model of sepsis is unclear, with either protective or harmful effects demonstrated, depending upon the time of intervention. We therefore hypothesize that IL-10 functions as a temporal regulator of the transition from early reversible sepsis to the late phase of irreversible shock. Transition from reversible sepsis to irreversible shock in the CLP model was defined as the time when removal of the necrotic cecum by rescue surgery is no longer effective. We subjected IL-10-deficient (IL-10(-/-)) and wild-type (IL-10(+/+)) mice to CLP and monitored the progression of sepsis, the onset of irreversible shock, and mortality. Onset of lethality in IL-10(-/-) mice occurred significantly earlier than in IL-10(+/+) mice and was associated with 15-fold-higher serum levels of TNF-alpha and IL-6. Consistent with these findings, the efficacy of rescue surgery after lethal CLP is lost 10 h earlier in IL-10(-/-) mice than in IL-10(+/+) mice. Treatment with recombinant human IL-10 5 h after CLP significantly improved survival and lengthened the therapeutic window for rescue surgery in both strains of mice. These results demonstrate that IL-10 controls the onset of irreversible septic shock after CLP.     

Resolvin D1 improves survival in experimental sepsis through reducing bacterial load and preventing excessive activation of inflammatory response

Sepsis is characterized as an uncontrolled inflammatory response. Spite et al. (Nature 461(7268):1287–1291, 2009) had demonstrated that resolvin D2, which is derived from docosahexaenoic acid (DHA), improves survival in cecal ligation and puncture (CLP)-initiated sepsis and enhances bacterial clearance without immune suppression. Resolvin D1, which is also derived from DHA and homologous with resolvin D2, is an endogenous anti-inflammatory and proresolving lipid molecule. We sought to investigate the effects of resolvin D1 on sepsis and to explore the mechanism of action. Six-to-eight-week-old male C57BL/6 mice were randomly divided into three groups: the sham group underwent the sham operation followed by tail vein injection of vehicle (0.1 % ethanol); the CLP group received vehicle (0.1 % ethanol) after CLP; the resolvin D1 group received resolvin D1 (100 ng) after CLP. Blood, peritoneal lavage fluid, and organs of mice were harvested 24 h after treatment for cytokine analysis, cell counts, bacterial cultures, histopathological studies, and apoptosis quantification. Compared with the vehicle control group, the survival rate and bacterial clearance of mice with sepsis induced by CLP were improved after resolvin D1 treatment, but the numbers of neutrophils in peritoneal lavage fluid, the inflammatory cytokines, the phosphorylation of the nuclear factor-κB (NF-κB) (P65) pathway, and the apoptosis rate of CD3⁺?T lymphocytes of the thymus were suppressed. Resolvin D1 treatment improved survival in mice with sepsis induced by CLP, enhanced organism bacterial clearance, suppressed the increase of the numbers of neutrophils in peritoneal lavage fluid, reduced the release of inflammatory cytokines, and decreased the apoptosis rate of CD3⁺?T lymphocytes of the thymus. These results suggest that resolvin D1 may attenuate the degree of inflammatory reaction in sepsis caused by CLP, without harming the host defense response.     

Protective effect of Ulinastatin against murine models of sepsis: Inhibition of TNF-α and IL-6 and augmentation of IL-10 and IL-13

AimExcessive production of inflammatory mediators during invasive infection plays a key role in the pathogenesis of sepsis. In an attempt to improve survival of patients with this lethal syndrome, agents were developed to selectively inhibit mediators in this inflammatory response. Ulinastatin (UTI), a human protease inhibitor, inhibits the enhanced production of pro-inflammatory molecules. However, it is unknown if Ulinastatin treatment could result in protective effects for sepsis. The aim of this study was to investigate the role of Ulinastatin on septic rats.MethodsSixty male Wistar rats were divided into six groups, 10 of each: sham-operation plus PBS (5 ml), cecal ligation and puncture (CLP) plus PBS (5 ml), CLP plus UTI (5000 U/kg), CLP plus UTI (10,000 U/kg), CLP plus UTI (20,000 U/kg) and sham-operation plus UTI (10,000 U/kg). Rats in the UTI groups after CLP operation were treated with Ulinastatin by intraperitoneal injection at different doses and then compared with untreated sepsis control animals.ResultsThe intestinal concentrations of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), and interleukin-13 (IL-13) were significantly higher in septic rats than those in normal rats. Ulinastatin administration effectively suppressed the levels of TNF-α and IL-6, whereas it markedly enhanced the levels of IL-10 and IL-13.ConclusionUlinastatin may possess a protective role in the septic process by inhibiting TNF-α and IL-6, and augmenting IL-10 and IL-13 concentrations in intestine of septic rats.     

The effect of sRAGE-Fc fusion protein attenuates inflammation and decreases mortality in a murine cecal ligation and puncture model

Objective

Inhibition of the receptor for advanced glycation end products (RAGE) may attenuate the systemic inflammatory response and ensuing severe sepsis. We report an investigation into the effect of soluble RAGE (sRAGE)-Fc fusion protein in severe sepsis induced by a cecal ligation and puncture (CLP) procedure.

Materials and methods

The experiment was performed using CLP control mice, mice treated with 0.5 or 1.0?μg sRAGE-Fc fusion protein, and sham surgery mice.

Results

Survival benefits over the CLP control group were evident (P?=?0.036) in mice given 1.0?μg sRAGE-Fc fusion protein. In addition, the pulmonary inflammation score in the sRAGE-Fc fusion protein-treated group was significantly lower than that in the CLP control group (P?<?0.05). Lung tissue in the sRAGE-Fc fusion protein-treated group revealed a significant decrease in the expression of inflammatory cytokines. Furthermore, levels of interleukin (IL)-1β and tumor necrosis factor-α were significantly lower in sRAGE-Fc fusion protein treated groups (P?<?0.001). Moreover, IL-6 levels showed a significant difference between CLP control and sRAGE-Fc fusion protein treated groups (P?<?0.01).

Conclusions

sRAGE-Fc fusion protein has beneficial effects in a standard murine model of polymicrobial, intra-abdominal severe sepsis.     

Pattern of cytokines and pharmacomodulation in sepsis induced by cecal ligation and puncture compared with that induced by endotoxin.

The production of tumor necrosis factor alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and IL-6 and their pharmacomodulation were evaluated in a model of polymicrobial sepsis induced in mice by cecal ligation and puncture (CLP) and were compared with the effects of endotoxin (lipopolysaccharide [LPS]) treatment. LPS levels rose as early as 1 h after CLP and increased further after 2 and 21 h. TNF-alpha was detectable in serum, spleen, liver, and lungs during the first 4 h, with a peak 2 h after CLP. IL-1 beta was measurable in serum after 24 h, and levels increased significantly in spleen and liver 4 and 8 h after CLP. IL-6 levels increased significantly in serum throughout the first 16 h after CLP. These cytokines were detectable after LPS injection, with kinetics similar to those after CLP but at a significantly higher level. To cast more light on the differences between these two animal models of septic shock, we studied the effects of different reference drugs. Pretreatment with dexamethasone (DEX); ibuprofen (IBU), an inhibitor of cyclooxygenase; and NG-nitro-L-arginine, an inhibitor of nitric oxide synthase, significantly reduced survival, while chlorpromazine (CPZ) and TNF did not affect it. Only the antibiotics and pentoxifylline significantly increased survival in mice with CLP. However, CPZ and DEX protected the mice from LPS mortality. On inhibiting TNF-alpha with DEX, CPZ, or pentoxifylline, survival was reduced, unchanged, and increased, respectively, and on increasing TNF-alpha with IBU and TNF, survival was decreased or unchanged, respectively, suggesting that the modulation of this cytokine does not play a significant role in sepsis induced by CLP, unlike treatment with LPS. The negative effects of IBU and N(G)-nitro-L-arginine suggest a protective role by prostaglandins and nitric oxide in sepsis induced by CLP.     

Rho Kinase Regulates Induction of T-Cell Immune Dysfunction in Abdominal Sepsis

T-cell dysfunction increases susceptibility to infections in patients with sepsis. In the present study, we hypothesized that Rho kinase signaling might regulate induction of T-cell dysfunction in abdominal sepsis. Male C57BL/6 mice were treated with the specific Rho kinase inhibitor Y-27632 (5 mg/kg of body weight) prior to cecal ligation and puncture (CLP). Spleen CD4 T-cell apoptosis, proliferation, and percentage of regulatory T cells (CD4⁺ CD25⁺ Foxp3⁺) were determined by flow cytometry. Formation of gamma interferon (IFN-γ) and interleukin 4 (IL-4) in the spleen and plasma levels of HMBG1, IL-17, and IL-6 were quantified by use of enzyme-linked immunosorbent assay (ELISA). It was found that CLP evoked apoptosis and decreased proliferation in splenic CD4 T cells. Inhibition of Rho kinase activity decreased apoptosis and enhanced proliferation of CD4 T cells in septic animals. In addition, CLP-evoked induction of regulatory T cells in the spleen was abolished by Rho kinase inhibition. CLP reduced the levels of IFN-γ and IL-4 in the spleen. Pretreatment with Y-27632 inhibited the sepsis-induced decrease in IFN-γ but not IL-4 formation in the spleen. CLP increased plasma levels of high-mobility group box 1 (HMGB1) by 20-fold and IL-6 by 19-fold. Inhibition of Rho kinase decreased this CLP-evoked increase of HMGB1, IL-6, and IL-17 levels in the plasma by more than 60%, suggesting that Rho kinase regulates systemic inflammation in sepsis. Moreover, we observed that pretreatment with Y-27632 abolished CLP-induced bacteremia. Together, our novel findings indicate that Rho kinase is a powerful regulator of T-cell immune dysfunction in abdominal sepsis. Thus, targeting Rho kinase signaling might be a useful strategy to improve T-cell immunity in patients with abdominal sepsis.     

Alveolar macrophage deactivation in murine septic peritonitis: role of interleukin 10

Sepsis predisposes the host to a number of infectious sequelae, particularly the development of nosocomial pneumonia. Mechanisms by which sepsis results in impairment of lung antibacterial host defense have not been well defined. Alveolar macrophages (AM) represent important immune effector cells of the lung airspace. In this study, we examined the effects of cecal ligation and puncture (CLP) on murine AM function ex vivo, including the expression of proinflammatory cytokines and AM phagocytic activity. AM were harvested from mice subjected to a sham operation and CLP 24 h after laparotomy, adherence purified, and challenged with lipopolysaccharide (LPS) or left unstimulated. Both unstimulated and LPS-stimulated AM from mice subjected to CLP (CLP mice) produced significantly smaller amounts of proinflammatory cytokines tumor necrosis factor alpha and interleukin (IL-12) and C-X-C chemokines KC and macrophage inflammatory protein 2 than similarly treated AM from animals subjected to a sham operation. Furthermore, AM isolated from CLP mice displayed a marked impairment in phagocytic activity, as determined by flow cytometry, with this defect persisting to 48 h post-CLP. Induction of peritoneal sepsis syndrome resulted in a time-dependent increase in IL-10 in plasma and peritoneal fluid. Interestingly, the impairment in AM proinflammatory-cytokine production and phagocytic activity observed in AM from CLP mice was partially reversed by the in vivo neutralization of IL-10 prior to AM harvest. These observations suggest that abdominal sepsis syndrome results in significant impairment in AM effector cell function, which is mediated, in part, by sepsis-induced expression of IL-10.