敲除巨噬细胞移动抑制因子基因可减轻小鼠重症急性胰腺炎相关肺损伤

目的:探讨巨噬细胞移动抑制因子（macrophage migration inhibitory factor, MIF）在小鼠重症急性胰腺炎（severe acute pancreatitis, SAP）相关肺损伤中的作用。方法:32只小鼠随机（随机数字法）分为4组（每组8只）：野生型对照组（WT+CON组）、野生型SAP组（WT+SAP组）、MIF基因敲除对照组（KO+CON组）、MIF基因敲除SAP组（KO+SAP组）。通过腹腔注射L-精氨酸（4 mg/g）制备SAP模型。在末次注射后72 h取材,通过ELISA检测血清淀粉酶（AMY）、白细胞介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）、MIF表达,通过HE染色观察胰腺组织及肺组织病理变化,通过免疫组化检测肺组织中IL-6、TNF-α表达,通过Western blot检测肺组织核因子κB（NF-κB）表达。计量资料两组间比较采用 t检验,多组比较采用单因素方差分析。 结果:与WT+CON组相比,WT+SAP组小鼠胰腺及肺组织损伤病理评分、AMY,血清及肺组织TNF-α、IL-6表达明显增高（ P<0.05）,而KO+SAP组以上指标水平明显减低（ P<0.05）。此外,KO+SAP组肺组织中NF-κB蛋白表达较WT+SAP组显著降低（ P<0.05）。 结论:敲除MIF基因可减轻小鼠SAP相关肺损伤,其作用机制可能与NF-κB有关。     

阻断toll样受体对脂多糖致急性肺损伤的保护作用

目的：本文旨在探讨阻断toll样受体（TRL4）对脂多糖（LPS）致急性肺损伤（ALI）的保护作用。方法将60只健康雄性清洁级SD大鼠分为正常组、损伤组和阻断组,每组20只。损伤组大鼠采用尾静脉注射LPS（6mg/kg）复制ALI模型;阻断组同时注射TLR4抗体（10mg/mL）;正常组给予等容积生理盐水。3h后处死大鼠,采用凝胶滞留法检测核因子-κB（NF-κB）活性;Westernblot印记分析法检测抑制蛋白（IκB-α）水平;检测肺组织匀浆肿瘤坏死因子α细胞因子（TNF-α）、白细胞介素-1β（IL-1β）和白细胞介素-10（IL-10）水平。结果与正常组相比,损伤组和阻断组肺组织湿质量/干质量比值增高,NF-κB活性升高,IκB-α、TNF-α、IL-1β水平升高（P＜0．05）,而IL-10水平降低（P＜0．05）。而比较损伤组与阻断组发现,阻断组肺组织湿质量/干质量比值降低,NF-κB活性降低,IκB-α、TNF-α、IL-1β水平明显低于损伤组（P＜0．05）,IL-10水平高于损伤组（P＜0．05）。结论采用抗TLR4单克隆抗体阻断TLR4介导的信号传导可明显降低NF-κB活性和IκB-α、TNF-α、IL-1β水平,同时提高IL-10水平阻断TLR4,对LPS致ALI有一定的保护作用。     

萝卜硫素对脓毒症急性肺损伤大鼠肺组织Toll样受体4/核因子κB信号通路的影响

目的评价萝卜硫素对于脓毒症急性肺损伤（ALI）大鼠肺组织炎症反应以及Toll样受体4（TLR4）/核因子κB（NF-κB）信号通路的影响。 方法将30只雄性Sprague Dawley大鼠按随机数字表法分成假手术组、模型组和治疗组,每组各10只。模型组和治疗组大鼠采用盲肠结扎穿孔（CLP）法制备大鼠脓毒症模型,治疗组大鼠在术后立即腹腔注射50 mg/kg的萝卜硫素注射液,其余两组注入等量等渗NaCl溶液;于术后24 h大鼠右侧颈总动脉采集动脉血标本,然后处死大鼠取肺组织测定肺组织湿/干比。采用酶联免疫吸附测定（ELISA）法检测三组大鼠肺组织匀浆标本肿瘤坏死因子α（TNF-α）、白细胞介素1β（IL-1β）、NF-κB p65表达水平;荧光实时定量PCR检测三组大鼠肺组织TLR4 mRNA的表达。 结果假手术组、模型组及治疗组大鼠肺组织湿/干比[（4.00 ± 0.13）、（6.10 ± 0.05）、（5.80 ± 0.08）]、氧合指数[（315 ± 11）、（177 ± 7）、（200 ± 12）mmHg]、TNF-α[（6.05 ± 0.29）、（45.06 ± 0.52）、（27.09 ± 0.85）ng/L]、IL-1β[（8.02 ± 0.21）、（38.23 ± 0.81）、（32.73 ± 1.12）ng/L]及NF-κB p65[（0.375 ± 0.013）、（1.230 ± 0.045）、（0.988 ± 0.043）ng/L]表达水平比较,差异均有统计学意义（F = 480.891、255.309、4 245.262、1 918.168、564.842,P均< 0.001）。进一步两两比较发现,模型组和治疗组大鼠肺组织湿/干比、TNF-α、IL-1β、NF-κB p65表达水平均较假手术组大鼠显著升高（P均< 0.05）,治疗组大鼠肺组织湿/干比、TNF-α、IL-1β、NF-κB p65表达水平均较模型组大鼠显著降低（P均< 0.05）;而模型组和治疗组大鼠氧合指数均较假手术组大鼠显著降低（P均< 0.05）,治疗组大鼠氧合指数较模型组大鼠显著升高（P < 0.05）。荧光实时定量PCR结果显示,三组大鼠肺组织TLR4 mRNA表达水平比较,差异具有统计学意义（F= 224.538,P < 0.001）。进一步两两比较发现,与假手术组比较,模型组及治疗组大鼠肺组织TLR4 mRNA表达均显著升高（P均< 0.05）;而治疗组大鼠肺组织TLR4 mRNA表达较模型组显著降低（P < 0.05）。 结论萝卜硫素可减轻脓毒症急性肺损伤大鼠肺组织炎症反应、肺水肿程度,改善缺氧状态,对于肺组织具有一定保护作用,且其作用机制可能与干预TLR4/NF-κB信号途径相关。     

去甲斑蝥素通过NF-κB/IκBα途径增强阿霉素的抗骨髓瘤效应

目的 研究去甲斑蝥素(NCTD)联合阿霉素(ADR)对多发性骨髓瘤细胞增殖、凋亡的影响及其机制.方法 以U266细胞为研究对象,采用NCTD(10 μmol/L)和ADR(0.25 μmol/L)单独或联合处理细胞,MTT法观察细胞增殖活力,流式细胞术检测细胞凋亡率,Western blot法检测核因子-κB P65( NF-κB P65)、磷酸化NF-κB P65( p-NF-κB P65)、NF-κB抑制因子IκBα、磷酸化IκBα(p-IκBα)、survivin、Bcl-2和Bax蛋白水平,免疫组化法测定血管内皮细胞生长因子(VEGF)水平.结果 ①NCTD能增强ADR的细胞毒和诱导凋亡作用,二者具有协同作用;②与ADR单药组比较,联合用药组胞核NF-κB P65和胞质p-IκBα的表达量分别由2.08±0.29和0.39±0.07降至0.48±0.08和0.02±0.01,胞质NF-κB P65和IκBα表达无变化;③联合用药组与ADR单药比较,survivin和Bcl-2的表达水平分别由0.31±0.05和0.23±0.05降至0.03±0.02和0.05±0.02,而Bax的表达由0.46±0.06升至0.62±0.08;④ADR组和联合用药组VEGF的阳性率分别为(44.6±4.4)％和(27.0±2.1)％,NCTD增强ADR对VEGF表达的抑制作用.结论 NCTD通过抑制NF-κB/IκBα途径,调节下游信号分子survivin、Bcl-2、Bax和VEGF的表达,增强ADR的抗骨髓瘤效应.     

Effect of N-acetylcysteine (NAC) on acute lung injury and acute kidney injury in hemorrhagic shock

Aim of the study

N-acetylcysteine (NAC) has been investigated to attenuate organ injury in various experimental and clinical studies. However, results in hemorrhagic shock (HS) were controversial. We determined the effects of continuous administration of NAC on acute lung injury (ALI) and acute kidney injury (AKI) in HS model.

Methods

Twenty male Sprague-Dawley rats were used. Pressure controlled HS model defined by mean arterial pressure (MAP) 40 ± 2 mmHg for 90 min followed by resuscitation and observation was used. Rats (n = 10 per group) were randomized into 2 groups with NAC or dextrose. Intravenous NAC was given continuously from 15 min after induction of HS to the end of observation period (2 h). We measured serum IL-6, nitrite/nitrate concentration. NF-κB p65 DNA binding activity, expressions of cytoplasmic phosphorylated IκB-α (p-IκB-α) and IκB-α, malondialdehyde (MDA) and histopathological injury scores in lung and kidney were also evaluated.

Results

MAP did not show any difference during the study period. NAC decreased histopathologic scores in both lung and kidney. Lung and kidney MDA levels were significantly lower in the NAC group compared to control group. Serum nitrite/nitrate and IL-6 were also significantly lower in the NAC group. The levels of lung cytoplasmic p-IκB-α expression was mitigated by NAC, and NF-κB p65 DNA binding activity was also significantly decreased in the NAC group.

Conclusions

Continuous infusion of NAC attenuated inflammatory response and acute lung and kidney injury after hemorrhagic shock in rats.     

经中心静脉途径注入腺病毒转载的核转录因子-κB抑制因子基因治疗大鼠感染性急性肺损伤

目的 观察经中心静脉途径注入腺病毒转载的核转录因子-kB(NF-kB)抑制因子(IkB)基因对感染性急性肺损伤(ALI)的治疗作用。方法 按随机数字表法将30只SD大鼠分为假手术组、ALI模型组、IkB治疗组,每组10只。IkB治疗组经中心静脉注入滴度为1×109 pfu腺病毒转载的IkB基因1 ml,假手术组和模型组注人生理盐水1 ml;然后模型组和IκB治疗组经尾静脉注入脂多糖(LPS,5 mg/kg)1ml复制ALI模型,假手术组则注入生理盐水1 ml。观察7d后大鼠的动脉血气分析,肺湿/干重(W/D)比值,血浆肿瘤坏死因子-α (TNF-α)、白细胞介素-6(IL-6)含量,肺组织NF-κBp65蛋白表达及光镜下肺组织病理改变,并计算肺损伤评分。结果 模型组死亡1只大鼠,其余大鼠均存活。3组间pH值、动脉血二氧化碳分压(PaCO2)比较无明显差异;动脉血氧分压(PaO2)假手术组最高,模型组最低。模型组血浆TNF-α (μg/L)、IL-6(ng/L)含量明显高于假手术组(TNF-α：5.20±1.09比3.01±0.46;IL-6:540.28±100.78比214.45±61.37,均P＜0.05);IkB治疗组血浆TNF-α和IL-6含量明显低于模型组(TNF-α.3.70±0.96比5.20±1.09;IL-6:356.49±60.58比540.28±100.78,均P＜0.05),其中TNF-α含量已恢复至假手术组水平。肺W/D比值：假手术组最低(4.49±0.36),模型组最高(5.78±0.43),IκB治疗组居中(5.33±0.38);肺损伤评分（分）：假手术组最低（0.17±0.41）,模型组最高(2.29±0.76),IκB治疗组居中（1.57±0.53）;肺NF-κB免疫组化评分（分）：假手术组最低(1.00±0.89),模型组最高(9.43±1.13),IκB治疗组居中(4.00±1.15);上述指标3组间两两比较差异均有统计学意义(均P＜0.05)。结论 经中心静脉途径注入腺病毒转载的IκB基因,可降低ALI大鼠血中炎症因子TNF-α、II-6含量,抑制NF-κB活化,减少肺水含量和肺泡塌陷以及肺实变,从而减轻肺损伤。     

Burn-induced acute lung injury requires a functional Toll-like receptor 4

The role of the Toll-like receptor 4 (TLR4), a component of the innate immune system, in the development of burn-induced acute lung injury (ALI) has not been completely defined. Recent data suggested that an intact TLR4 plays a major role in the development of organ injury in sterile inflammation. We hypothesized that burn-induced ALI is a TLR4-dependent process. Male C57BL/6J (TLR4 wild-type [WT]) and C57BL/10ScN (TLR4 knockout [KO]) mice were subjected to a 30% total body surface area steam burn. Animals were killed at 6 and 24 h after the insult. Lung specimens were harvested for histological examination after hematoxylin-eosin staining. In addition, lung myeloperoxidase (MPO) and intercellular adhesion molecule 1 immunostaining was performed. Lung MPO was measured by an enzymatic assay. Total lung keratinocyte-derived chemoattractant (IL-8) content was measured by enzyme-linked immunosorbent assay. Western blot was performed to quantify phosphorylated IκBα, phosphorylated nuclear factor κB p65 (NF-κBp65), and high mobility group box 1 expression. Acute lung injury, characterized by thickening of the alveolar-capillary membrane, hyaline membrane formation, intraalveolar hemorrhage, and neutrophil infiltration, was seen in WT but not KO animals at 24 h. Myeloperoxidase and intercellular adhesion molecule 1 immunostaining of KO animals was also similar to sham but elevated in WT animals. In addition, a reduction in MPO enzymatic activity was observed in KO mice as well as a reduction in IL-8 levels compared with their WT counterparts. Burn-induced ALI develops within 24 h after the initial thermal insult in our model. Toll-like receptor 4 KO animals were clearly protected and had a much less severe lung injury. Our data suggest that burn-induced ALI is a TLR4-dependent process.     

Anticancer agent 2-methoxyestradiol improves survival in septic mice by reducing the production of cytokines and nitric oxide

Cytokine production is critical in sepsis. 2-Methoxyestradiol (2ME2), an endogenous metabolite of estradiol, inhibits hypoxia-inducible factor 1α (HIF-1α) and is an antiangiogenic and antitumor agent. We investigated the effect of 2ME2 on cytokine production and survival in septic mice. Using i.p. LPS or cecal ligation and puncture (CLP), sepsis was induced in BALB/c mice that were simultaneously or later treated with 2ME2 or vehicle. Twelve hours after the LPS injection, serum and peritoneal fluid cytokine and nitric oxide (NO) levels were analyzed using enzyme-linked immunosorbent assay and the Griess reaction. Lung injuries were histologically analyzed, and liver and kidney injuries were biochemically analyzed. Survival was determined 7 days after LPS injection or CLP procedure. In vivo and in vitro effects of 2ME2 on LPS-induced macrophage inflammation were determined. The effect of 2ME2 on HIF-1α expression, nuclear factor κB (NF-κB), and inducible NO synthase (iNOS) in LPS-treated RAW264.7 cells, a murine macrophage cell line, was determined using Western blotting. 2-Methoxyestradiol treatment reduced LPS-induced lung, liver, and kidney injury. Both early and late 2ME2 treatment prolonged survival in LPS- and CLP-induced sepsis. 2-Methoxyestradiol significantly reduced IL-1β, IL-6, TNF-α, and NO levels in septic mice as well as in LPS-stimulated peritoneal macrophages. 2-Methoxyestradiol treatment also reduced the LPS-induced expression of HIF-1α, iNOS, and pNF-κB in RAW264.7 cells, as well as iNOS and pNF-κB expression in siHIF-1α-RAW264.7 cells. 2-Methoxyestradiol prolongs survival and reduces lung, liver, and kidney injury in septic mice by inhibiting iNOS/NO and cytokines through HIF-1α and NF-κB signaling.     

甘草酸二铵对急性肺损伤大鼠肺组织糖皮质激素受体及核因子κB表达的影响

目的 观察甘草酸二铵(GL)对急性肺损伤(ALI)大鼠肺组织核因子κB(NF-κB)、糖皮质激素受体(GR)表达的调控作用及对血清肿瘤坏死因子α(TNF-α)、白细胞介素10(IL-10)表达的影响.方法 将24只雄性SD大鼠采用随机数字表法分为生理盐水对照组、ALI模型组和GL干预组,每组8只.ALI模型组、GL干预组分别给予内毒素(LPS)5 mg/kg尾静脉注射;IPS注射前1 h,GL干预组给予GL 20 mg/kg静脉注射.观察4 h后各组大鼠肺组织病理,测定肺湿干比(W/D)、PaO_2,并采用逆转录-PCR反应检测肺组织NF-κB mRNA,GR mRNA的表达,western blot法测定肺组织Nf-κB及GR蛋白的表达,ELISA法测定血清TNF-α,IL-10质量浓度.采用SPSS 13.0软件进行统计学分析,各组间均数比较采用单因素方差分析,均数两两比较采用q检验.结果 (1)ALI模型组TNF-α为(153.68±20.42)ng/L,明显高于生理盐水组(43.96±7.57)ng/L(P<0.01)和GL干预组(87.23±7.52)ng/L(P<0.01).ALI模型组IL-10为(42.48±6.81)ug/L,明显高于生理盐水组(24.72±8.03)ng/L(P<0.01),但低于GL干预组水平(58.33±9.62)ug/L(P<0.05).(2)ALI模型组NF-κBmRNA和蛋白的表达水平[分别为(3.414±0.521),(254.7±16.4)]明显高于生理盐水组[分别为(0.432±0.085),(45.6±7.3)](P<0.01),而GRmRNA和蛋白的表达[分别为(0.152±0.025),(11.5±2.3)]则明显低于生理盐水组[分别为(0.434±0.013),(54.6±6.5)](P<0.01);GL干预组NF-κB mRNA和蛋白的表达水平[分别为(1.894±0.272),(133.5±11.7)]明显低于ALI模型组(P<0.01),GR mRNA和蛋白的表达[分别为(0.308±0.033),(28.2±5.6)]则明显高于ALI模型组(P<0.05,P<0.01).(3)ALI模型组肺组织出现充血、水肿、中性粒细胞浸润,GL干预组肺部炎症较ALI模型组减轻.结论 甘草酸二铵可能通过下调NF-κB的表达,同时提高GR的表达,进而调节炎症因子TNF-α及抗炎介质IL-10的表达,从而起到减轻ALI的作用.     

Inducible nitric oxide synthase inhibitor reverses exacerbating effects of hypertonic saline on lung injury in burn

The use of hypertonic saline (HTS) resuscitation in major trauma patients is still controversial. The objective of this study is to determine if inhibition of inducible nitric oxide synthase (iNOS) to stabilize the endothelial permeability and to retain HTS in the vascular space will reverse its exacerbating effect on burn-induced lung damage. In Experiment 1, specific pathogen-free (SPF) rats underwent 35% total body surface area (TBSA) burn and were resuscitated with 7.5 mL/kg HTS (7.5% NaCl), 7.5 mL/kg saline, or 50 mL/kg saline (nearly equal sodium load as HTS) via femoral veins for 15 min immediately after the burn. In Experiment 2, S-methylisothiourea (SMT) (7.5 mg/kg, i.p.) was given immediately after the burn to rats from the different groups of Experiment 1. At 8 h after the burn, the permeability and myeloperoxidase (MPO) activity of lung tissues were determined, and plasma samples were assayed for peroxynitrite levels. Burn significantly induced lung MPO activity, lung permeability, and blood dihydrorhodamine 123 (DHR 123) oxidation in rats. HTS administration after burn significantly increased the blood DHR 123 oxidation level, lung MPO activity, lung permeability, and inflammatory cell infiltration in comparison with those of burn plus 7.5 mg/kg saline and burn plus 50 mL/kg saline rats. In contrast, burn plus SMT rats with HTS injection showed significant 54%, 11%, and 35% decreases in blood DHR 123 oxidation level, lung MPO activity, and lung permeability, respectively, in comparison with burn plus SMT plus 7.5 mg/kg saline rats. In conclusion, restoration of extracellular fluid in early burn shock with HTS supplementation significantly exacerbates burn-induced lung neutrophil deposition, lung hyperpermeability, and blood peroxynitrite production. Inhibition of iNOS before HTS supplementation reverses the deteriorating effects of HTS on thermal injury-induced lung damage to beneficial ones. Using HTS in thermal injury resuscitation without the inhibition of iNOS is dangerous.     

糖皮质激素对大潮气量机械通气大鼠肺组织巨噬细胞炎症蛋白-1 α和核因子-κB表达的影响

目的 观察大潮气量机械通气大鼠血浆和支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)巨噬细胞炎症蛋白-1α(MIP-1α)含量以及肺组织MIP-1α mRNA和NF-κBp65 mRNA表达水平.方法 32只健康雄性Wistar大鼠随机(随机数字法)分为对照组,机械通气致肺损伤(VILI)组、地塞米松干预(DEX)组和布地奈德干预(BUD)组.给与相应处理后分别采用ELISA法检测各组大鼠BALF和血浆MIP-1α含量,采用RT-PCR法检测其肺组织MIP-1αmRNA和NF-κB p65mRNA表达水平,比较4组之间的差异,并将VILI,DEX,BUD组间MIP-1α mRNA与MIP-1α含量,MIP-1α mRNA与NF-κB p65 mRNA表达水平间进行直线相关分析.结果 DEX组和BUD组BALF及血浆中MIP-1α含量及肺组织MIP-1αmRNA和NF-κBp65 mRNA表达水平均明显低于VILI组(P＜0.05),同时肺组织损伤程度明显减轻;BUD组BALF和血浆中MIP-1α含量及肺组织MIP-1α mRNA和NF-κB p65 mRNA表达水平虽高于DEX组,但差异无统计学意义(P＞0.05).相关分析结果表明,肺组织MIP-1α mRNA表达量与BALF中MIP-1α含量呈正相关(r=0.895,P＜0.05);肺组织MIP-1α mRNA表达量与NF-κB p65 mRNA表达量呈正相关(r=0.801,P＜0.05).结论 糖皮质激素可能通过抑制NF-κB的活性而下调肺组织MIP-1α的表达,对VILI有一定防治作用;局部应用糖皮质激素对VILI的保护作用与全身用药的作用相似,且副作用小.     

贝那鲁肽对高糖诱导的胰岛 β细胞功能障碍和凋亡的影响及机制研究

目的　探讨贝那鲁肽对高糖诱导的胰岛 β细胞功能障碍和凋亡的影响以及相关机制。方法　将 INS-1胰岛 β细胞随机分为对照组、高糖组、贝那鲁肽处理组、 MG-132预处理组和 ISO-1预处理组,对照组给予 5.5mmol/L葡萄糖处理,高糖组给予 30 mmol/L葡萄糖处理,贝那鲁肽处理组在高糖组的基础上给予 1 nmol/L贝那鲁肽处理, MG-132预处理组和 ISO-1预处理组分别在高糖的基础上给予 20 μmol/L MG-132和 50 μmol/L ISO-1预处理。培养 24h后噻唑蓝（ MTT）比色法评估细胞的活力,酶联免疫吸附法（ ELISA）检测 INS-1胰岛 β细胞胰岛素和巨噬细胞迁移抑制因子（ MIF）的分泌, Western blot检测凋亡相关蛋白（ Bax和 cleaved caspase 3）和 NF-κB通路相关蛋白（ p-IκB,IκB和 NF-κBp65）的表达。结果　与对照组相比,高糖组胰岛 β细胞的存活率（ t=4.949,P＜ 0.01）、胰岛素的分泌（ t=3.168, 4.273,均 P＜ 0.05）和 IκB的表达（ t=3.062,P＜ 0.05）明显降低,凋亡相关蛋白（ Bax和 cleaved caspase 3）的表达（ t=2.923, 3.141,均 P＜ 0.05）、p-IκB和 NF-κB p65表达（ t=3.544, 4.658,均 P＜ 0.01）以及 MIF分泌（ t=3.024,P＜ 0.05）明显增加 .与高糖组相比,贝那鲁肽处理组可逆转高糖组上述指标的变化（ t=2.415 ~ 4.290,均 P＜ 0.05）,差异均有统计学意义。进一步给予 NF-κB抑制剂 MG-132和 MIF抑制剂 ISO-1预处理后,与高糖组相比, MG-132预处理组和 ISO-1预处理组均可改善高糖诱导的 INS-1胰岛 β细胞胰岛素分泌功能（ t=2.515 ~ 6.867,均 P＜ 0.05）,还可降低凋亡相关蛋白 Bax（t=4.022,     

黄芪甲苷对病毒性心肌炎小鼠TLR4、NF-κB及TNF-α表达的影响

目的探讨黄芪甲苷对病毒性心肌炎小鼠Toll样受体4(TLR4) mRNA、核因子-κB(NF-κB) mRNA表达及血清肿瘤坏死因子(TNF-α)的影响。方法将80只雄性BALB/c小鼠随机分为柯萨奇病毒感染组(感染组,30只)、黄芪甲苷治疗组(治疗组,30只)和正常对照组(对照组,20只)。感染组和治疗组小鼠腹腔注射柯萨奇病毒B3(CVB3),建立病毒性心肌炎模型。治疗组于注射病毒后30min开始灌服黄芪甲苷,每日1次×7d;感染组以生理盐水灌胃;对照组用不含病毒的Eagle液腹腔注射、生理盐水灌胃。各组分别在7d、14d各随机抽取8只小鼠处死,HE染色后检测心肌病理积分、逆转录-聚合酶链反应(RT-PCR)检测心肌中TLR4 mRNA和NF-κB mRNA的表达,ELLSA法检测血清TNF-α的含量。结果感染组心肌病理积分、TLR4 mRNA、NF-κB mRNA表达及血清TNF-α的含量较对照组明显增加(P<0.01),治疗组心肌病理积分、TLR4 mRNA、NF-κB mRNA表达及血清TNF-α的含量较感染组明显降低(P<0.05)。结论黄芪甲苷可以通过调节TLR4、NF-κB及TNF-α在病毒性心肌炎中的表达,减轻心肌损伤。     

NF-κB和诱导型一氧化氮合酶在大鼠慢性阻塞性肺疾病中的作用

目的探讨NF-κB、诱导型一氧化氮合酶（iNOS）在慢性阻塞性肺疾病（COPD）发病机制中的作用。方法采用两次气管内注入脂多糖（LPS）和反复烟熏的方法制作COPD大鼠模型;采用免疫组织化学法检测NF-κB、iNOS在COPD大鼠支气管肺组织中的表达。结果大鼠模型的病理及病理生理学改变符合人类COPD的特点,模型组肺平均内衬间隔（MLI）、平均肺泡数（MAN）与对照组比较差异有统计学意义（P〈0.01）,模型组NF-κB、iNOS表达强度明显高于对照组（P〈0.05）。结论NF-κB、iNOS的过量表达引起气道炎症和肺部损伤,导致COPD的发生;同时NF-κB促进炎症细胞合成多种炎症因子,产生大量的iNOS,在COPD气道炎症和肺部损伤的持续和放大中起着重要作用。     

急性肺损伤大鼠肺组织肝脏X受体α表达的研究

目的 观察内毒素性急性肺损伤(ALI)大鼠肝脏X受体α(LXRα)的改变,探讨LXRα在ALI发病中的作用机制.方法 将48只Wistar大鼠随机均分为两组.采用尾静脉注射脂多糖(LPS)5 mg/kg复制大鼠ALI模型,对照组静脉注射生理盐水2.5 ml/kg.于致伤后1、2、4和8 h取大鼠动脉血进行血气分析及肿瘤坏死因子-α(TNF-α)水平检测;取肺测定肺湿/干重(W/D)比值、髓过氧化物酶(MPO)活性及肺组织病理学改变;用逆转录-聚合酶链反应(RT-PCR)检测肺组织LXRα mRNA、TNF-α mRNA表达;用酶联免疫吸附法(ELISA)检测TNF-α含量变化;用免疫组化法观察肺组织LXRα蛋白表达情况.结果 与对照组比较,ALI组致伤后各时间点动脉血氧分压(PaO2)均显著降低,肺W/D比值、MPO活性均显著升高(P均<0.05);病理观察显示肺组织受损;肺组织LXRα mRNA表达下降,TNF-α mRNA表达升高(p均<0.05),肺组织匀浆和动脉血清中TNF-α亦显著升高,4 h达高峰.免疫组化显示对照组肺组织表达较高水平LXRα蛋白,ALI组在LPS致伤后可见LXRα蛋白表达较对照组显著下降(P均<0.05).结论 正常大鼠肺组织可表达LXRα,LPS可引起ALI大鼠肺组织LXRα的基因和蛋白表达下降,这可能与ALI发病有关.     

慢性盆腔炎模型大鼠中miR-29 及炎症信号通路分子的表达水平及其作用机制研究

目的 探究微小核糖核酸(micro RNA,miR)-29 对大鼠慢性盆腔炎模型的作用并探究其作用机制。方法 将80 只SPF 级SD 大鼠随机分为四组,分别为对照组(n=20)、模型组(n=20)、阴性对照组(n=20)和试验组(n=20)。模型组、阴性对照组和试验组通过机械损伤及接种混合菌构建大鼠慢性盆腔炎模型,阴性对照组和试验组造模后通过尾静脉注射5nmol 阴性对照(negative control, NC)antagomiR 和miR-29 antagomiR。HE 染色检测大鼠子宫组织病理特性;酶联免疫吸附测定(enzyme linked immunosorbent assay,ELISA)法检测各组大鼠外周血炎症相关指标:白细胞介素(interleukin,IL)-1β,白细胞介素(IL)-6,白细胞介素(IL)-8 和肿瘤坏死因子(tumor necrosis factor,TNF)-α 水平;实时荧光定量PCR(quantitative real-time PCR,qPCR)检测子宫组织miR-29,Toll 样受体4(Toll-like receptors,TLR)4,核因子κB(nuclear factor,NF-κB)及NK-κB 抑制蛋白α(IκB α)表达水平;WesternBlot 检测子宫组织TLR4,NF-κB 和IκB α 蛋白表达水平。结果 HE 染色结果表明,与对照组相比,模型组、阴性对照组和试验组大鼠出现明显慢性盆腔炎症状,试验组子宫组织损伤显著缓解;ELISA 结果表明:模型组大鼠外周血IL-1β,IL-6,IL-8 和TNF-α 水平显著高于对照组,与模型组和阴性对照组相比,试验组炎症因子IL-1β,IL-6,IL-8 和TNF-α 释放显著降低,差异有统计学意义(t=3.021 ～ 6.878,均P ＜ 0.05);qPCR 结果表明,与对照组相比,模型组miR-29,TLR4,NF-κB 和IκB α 的mRNA 表达显著上升,与模型组和阴性对照组相比,试验组miR-29 ,TLR4,NF-κB 和IκB α的 mRNA 表达显著降低,差异有统计学意义(t=3.917 ～ 8.095,均P ＜ 0.05)。Western Blot 结果表明:与对照组相比,模型组TLR4,NF-κB 和IκB α 蛋白表达显著上升,与模型组和阴性对照组相比,试验组TLR4,NF-κB 和IκBα 蛋白表达显著降低,差异有统计学意义(t=2.987 ～ 8.045,均P ＜ 0.05)。结论 慢性盆腔炎模型大鼠子宫组织中miR-29 显著高表达,下调miR-29 具有对大鼠子宫的保护作用,其机制可能与抑制炎症因子释放及TLR4/NF-κB 信号通路的调控相关。     

褪黑素抑制大鼠急性肺损伤时核转录因子-κB的表达

目的 探讨褪黑素(MT)对大鼠急性肺损伤(ALI)时肺脏的保护作用及其可能机制.方法 将96只SD大鼠随机分为4组:对照组、脂多糖(LPS)组、地塞米松(DEX)和MT组,每组24只.采用气道内滴注LPS制备ALI大鼠模型;DEX和MT干预采用腹腔注射.分别于给药后3、6和12 h活杀各组大鼠取肺组织标本,检测肺组织中髓过氧化物酶(MPO)和超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量;用免疫组化方法检测核转录因子-κB(NF-κB)在肺组织的表达.结果 LPS组各时间点SOD活性较对照组明显降低(P<0.05或P<0.01),而MPO活性与MDA含量以及NF-κB的表达则显著升高(P<0.05或P<0.01);应用MT及DEX均能显著缓解上述变化(P<0.05或P<0.01);上述各指标以6 h变化最为显著,分别达到峰值或谷底.结论 MT对ALI时肺脏的保护作用可能与MT清除自由基及抑制NF-κB的激活有关.     

内皮源性toll样受体4在急性肺损伤中的作用

目的 探索内皮源性或髓源性细胞表面toll样受体4(TLR4)介入急性肺损伤(ALI)的作用. 方法 采用TLR4基因突变(C3H/HeJ品系,TLR4mut/mut)及野生型(C3H/HeN,TLB4+/+)小鼠,通过骨髓移植建立"内皮细胞TLR4+/+髓系细胞TLR4mut/mut"(WT/Mutant:受体/供体)及Mutant/WT嵌合体小鼠,尾静脉注射LPS(5 mg·kg-1)复制ALI模型,5 h后测肺组织湿干重比(W/D),肺通透指数(LPI),肺组织髓过氧化物酶(MPO)水平、炎症因子及黏附分子水平. 结果 TLR4mut/mut小鼠肺损伤较TLR4+/+小鼠较轻,WT/Mutant组小鼠肺组织损伤较Mutant/WT组重,且WT/Mutant组与WT/WT组差异无统计学意义.WT/Mutant组小鼠肺组织MPO水平、ICAM-1表达水平较Mutant/WT组高,且ICAM-1表达水平WT/Mutant组小鼠与WT/WT小鼠比较差异无统计学意义.炎症因子TNF-α、IL-1β的水平Mutant/WT组较WT/Mutant组高. 结论 内皮源性TLR4通过调控黏附分子表达而促进PMN肺组织招募,在介导LPS诱导的ALI中的发挥核心作用.