Comparing the protective effects of ciprofloxacin, moxifloxacin and levofloxacin in mice with lipopolysaccharide-induced acute lung injuries

Background and objective:   Ciprofloxacin, moxifloxacin and levofloxacin are recognized immunomodulators. Their effects in acute lung injuries have not been tested. This study compared the immunoprotective effects of these agents in mice with lung injuries induced by LPS by measuring the cytokine profiles in the injured lung and the associated mortality.
Methods:   The development of lung injury and mortality was compared in mice pretreated with either ciprofloxacin, levofloxacin, moxifloxacin or saline (control group) after the intratracheal administration of LPS. BALF and serum were collected at 1, 3 and 6 h to measure the concentrations of tumour necrosis factor-α (TNF-α), IL-1β, IL-6, IL-10 and macrophage inflammatory protein-2 (MIP-2) using enzyme-linked immunoassay.
Results:   Levels of TNF-α, IL-1β and MIP-2 in the BAL of the ciprofloxacin group were significantly lower compared with those of controls (all P  < 0.0083) at 3 and 6 h after LPS challenge. There were no significant differences in the levels of these cytokines in the moxifloxacin and levofloxacin groups compared with controls. Overall, the 96-h survival for the mice pretreated with ciprofloxacin, but not for those pretreated with moxifloxacin or levofloxacin, was significantly greater than that of the control animals ( P  = 0.019).
Conclusions:   In the setting of LPS-induced lung injuries, ciprofloxacin appears to provide better anti-inflammatory properties and survival benefits than the other fluoroquinolones tested.     

Attenuation of lipopolysaccharide-induced acute lung injury by treatment with IL-10

Background and objective:   The aim of this study was to characterize the changes in neutrophils and cytokines in BAL fluid following acute lung injury (ALI), and to determine the protective effect of post-injury treatment with IL-10.
Methods:   A rat model of ALI was established by evenly spraying LPS (16 mg/kg) into the lungs followed by observation for 48 h. Histological changes and the kinetics of neutrophil infiltration were evaluated in the injured lungs. The cytokines (TNF-α, IL-6, IL-10 and interferon-γ) and macrophage-inflammatory protein (MIP-2) were measured in BAL fluid by ELISA. The activation of BAL fluid neutrophils was investigated after treatment with IL-10 in vitro . The protective effect on histology and MIP-2 levels of intra-tracheal instillation of IL-10 12 and 16 h after LPS treatment was studied in vivo.
Results:   Intra-tracheal instillation of LPS caused significant lung injury and the activation of neutrophils. The levels of TNF-α and IL-6 in BAL fluid peaked at 8 and 16 h after LPS instillation respectively. IL-10 levels reached a maximum at 16–24 h, at the beginning of resolution of tissue injury. IL-10 inhibited the activation of neutrophils in vitro and MIP-2 induction in vivo . IL-10 had a protective effect if it was administered 12 but not 16 h after LPS.
Conclusions:   Neutrophils appeared to play an important role in ALI. Time-dependent treatment with IL-10 after intra-tracheal instillation of LPS was effective in protecting rats from ALI, probably by suppressing pulmonary infiltration with activated neutrophils.     

Opposite effects of ANP receptors in attenuation of LPS-induced endothelial permeability and lung injury

Atrial natriuretic peptide (ANP) has been recently identified as a modulator of acute lung injury (ALI) induced by pro-inflammatory agonists. While previous studies tested effects of exogenous ANP administration, the role of endogenous ANP in the course of ALI remains unexplored. This study examined regulation of ANP and its receptors NPR-A, NPR-B and NPR-C by LPS and involvement of ANP receptors in the modulation of LPS-induced lung injury. Primary cultures of human pulmonary endothelial cells (EC) were used in the in vitro tests. Expression of ANP and its receptors was determined by quantitative RT-PCR analysis. Agonist-induced cytoskeletal remodeling was evaluated by immunofluorescence staining, and EC barrier function was characterized by measurements of transendothelial electrical resistance. In the murine model of ALI, LPS-induced lung injury was assessed by measurements of protein concentration and cell count in bronchoalveolar lavage fluid (BAL). LPS stimulation significantly increased mRNA expression levels of ANP and NPR-A in pulmonary EC. Pharmacological inhibition of NPR-A augmented LPS-induced EC permeability and blocked barrier protective effects of exogenous ANP on LPS-induced intercellular gap formation. In contrast, pharmacological inhibition of ANP clearance receptor NPR-C significantly attenuated LPS-induced barrier disruptive effects. Administration of NPR-A inhibitor in vivo exacerbated LPS-induced lung injury, whereas inhibition of NPR-C suppressed LPS-induced increases in BAL cell count and protein content. These results demonstrate for the first time opposite effects of NPR-A and NPR-C in the modulation of ALI and suggest a compensatory protective mechanism of endogenous ANP in the maintenance of lung vascular permeability in ALI.     

Protective effect of bicyclol on lipopolysaccharide-induced acute lung injury in mice

Bicyclol is synthesized based on schisandrin, which is one of the main active components of Chinese herb Fructus Schisandrae. The purpose of this study is to investigate whether bicyclol has a beneficial effect on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. Bicyclol was given to mice by gavage for three times. ALI was induced by vena caudalis injection of LPS. The last dose of bicyclol was administrated 1 h before LPS given. Mice in each group were sacrificed at different time point after LPS administration. As revealed by survival study, pretreatment with high doses of bicyclol reduced the mortality of mice from ALI. Bicyclol pretreatment significantly improved LPS-induced lung pathological changes, inhibited myeloperoxidase (MPO) activity, and reduced lung/body and lung wet/dry weight ratios. Bicyclol also inhibited the release of TNF-α, IL-1β and HMGB1, whereas simultaneously increased the expression of IL-10. Furthermore, the phosphorylation level of NF-κB p65 was markedly decreased by bicyclol. Taken together, our study showed that bicyclol improves survival rate and attenuates LPS-induced ALI. The protective mechanism may be due to the inhibition of NF-κB activation and regulation of cytokine secretion.     

Effects of free radical scavenger on acute liver injury induced by d-galactosamine and lipopolysaccharide in rats.

Aim: Acute severe liver injury still has a high mortality rate. Acute liver injury induced by a coadministration of d-galactosamine (GalN) and lipopolysaccharide (LPS) is an experimental model of fulminant hepatitis in rats. Our aim is to investigate the effects of free radical scavenger on the injury induced by GalN/LPS in rats. Methods: Free radical scavenger edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) was twice injected into rats 5 min before and 60 min after the GalN/LPS injection. Liver injury was biochemically and histologically assessed. The survival rate was examined 72 h after the intoxication. Results: In the GalN/LPS-treated rats, a marked elevation in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels was observed. On the other hand, edaravone significantly inhibited the elevation in serum AST and ALT levels. The efficacy of edaravone was also confirmedby histological analysis. Edaravone lowered the levels of proinflammatory cytokines TNF-alpha mRNA and interleukin-6 mRNA expression, antioxidative enzyme heme oxygenase-1 protein and myeloperoxidase activity, a marker of neutrophil infiltration, in rat livers. In addition, edaravone reduced the mortality rate in GalN/LPS-treated rats as compared to the rats without edaravone treatment. Conclusions: Free radical scavenger edaravone effectively ameliorated the liver injury induced by the GalN/LPS administration in rats, not only by attenuating oxidative stress, but also by reducing the expression of proinflammatory cytokines.     

Resolvin D1 protects mice from LPS-induced acute lung injury

Resolvin D1 (RvD1), an endogenous lipid molecule derived from docosahexaenoic acid (DHA), has been described to promote inflammatory resolution. The present study aimed to determine the protective effects and the underlying mechanisms of RvD1 on lipopolysaccharide (LPS)-induced acute lung injury (ALI). Pretreatment RvD1 to mice 30 min before inducing ALI by LPS decreased the mortality and improved lung pathological changes, inhibited LPS-induced increases in polymorphonulear and mononuclear leukocytes recruitment, total proteins content, tumor necrosis factor (TNF-α) and interleukin-6 (IL-6) production in the bronchoalveolar lavage fluids (BALFs). In addition, RvD1 markedly reduced LPS-induced the expression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and adhesion molecules, as well as myeloperoxidase (MPO) activity. Moreover, RvD1 markedly inhibited LPS-induced the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB). Furthermore, pretreatment with Boc, a lipoxin A4 receptor (ALX) antagonist, significantly reversed these beneficial effects of RvD1 on LPS-induced acute lung injury in mice. Taken together, our study showed that RvD1 improved survival rate and attenuated ALI in mice induced by LPS, and the protective mechanisms might be related to selective reaction with ALX, which inhibits MAPKs and NF-κB pathway.     

红景天苷对脂多糖所致急性肺损伤治疗作用的研究

目的:观察红景天苷（SDS）对脂多糖（LPS）引起的大鼠急性肺损伤（ALI）的治疗作用,并初步探讨其作用的机制。方法: 将36只SD大鼠随机分为生理盐水（NS）对照组、LPS组和LPS+SDS组(每组n=12),通过向气管内滴注LPS建立大鼠ALP模型。采用微量注射泵向大鼠右颈外静脉注射液体并留置的给药方法,NS组和LPS组注射NS并留置4 h;LPS+SDS组先于气管内滴注LPS,0.5 h后再注射SDS并留置4 h。4.5 h后处死实验动物,取肺组织观察其形态学改变,测定肺湿/干质量的比值（W/D）、肺泡灌洗液（BALF）中蛋白的含量及肺组织匀浆中TNF-α、IL-6、IL-10、乳酸脱氢酶(LDH)和髓过氧化物酶(MPO)的含量。结果: 形态学观察表明,LPS组肺组织水肿,有点、片状出血及大量的炎性细胞浸润,肺泡间隔显著增厚,肺泡腔变窄、结构消失。LPS+SDS组的肺组织损伤明显减轻,肺组织结构趋于正常,肺泡腔及支气管腔炎细胞及渗出物与LPS组相比明显减少。LPS组肺W/D与NS组相比明显增加（P<0.05）,BALF中蛋白的含量显著增加（P<0.05）,肺组织匀浆中TNF-α、IL-6、IL-10、LDH和MPO的含量显著增加（P<0.05）;而给予SDS治疗后,肺W/D、BALF中蛋白含量、肺组织匀浆中TNF-α、IL-6、LDH和MPO的含量与LPS组相比均明显减少（P<0.05）,IL-10含量显著增加（P<0.05）。结论: SDS对LPS所致ALI具有治疗作用,这种治疗作用可能与其通过抑制肺组织中炎症介质的作用有关。     

Effects of intratracheal tumor necrosis factor-alpha plasmid vector on lipopolysaccharide lethality and lung injury in mice

Bacterial lipopolysaccharide (LPS) causes acute lung injury (ALI) and contributes to inflammation in the acute respiratory distress syndrome (ARDS) and sepsis, making mechanisms of resistance to LPS critically important in clinical settings. The authors postulated that intratracheal administration of a plasmid (pcDNA3. 0-rTNFalpha) encoding rat tumor necrosis factor-alpha (TNF-alpha) would increase resistance of mice to LPS-induced ALI or mortality. They investigated the time course and dose-response for development of LPS-induced ALI in C57/BL6 mice and sought possible protective effects of 100 microg pcDNA3.0-rTNFalpha intratracheally 1, 2, or 3 weeks before LPS challenge. Lung myeloperoxidase (MPO) activity and alveolar lavage fluid (BALF) cell counts increased significantly 48 hours after intraperitoneal (IP) LPS challenges. After pcDNA3.0-rTNFalpha pretreatment, mice challenged with LPS had lower lung/body weight ratios than mice treated with pcDNA3.0; however, other indices of lung injury did not differ. Survival of mice challenged with lethal IP LPS 2 weeks after intratracheal pcDNA3.0-rTNFalpha vector improved significantly, compared to mice pretreated with the control vector, pcDNA3.0. However, pcDNA3.0-pretreated mice tolerated LPS challenge less well than saline-pretreated controls. LPS causes neutrophilic lung injury and mortality, but pcDNA3.0-TNFalpha does not prevent ALI due to LPS. Intratracheal pcDNA3.0-rTNFalpha pretreatment significantly improves survival of mice after LPS challenge, compared to those pretreated with pcDNA3.0.     

Electrical impedance tomography is able to track changes in respiratory function in endotoxin-challenged rodents

Background and objective:   In order to assess and optimize the effect of new therapies for acute lung injury (ALI) in rodent models, a monitoring technique that continuously assesses the functional state of the lung is mandatory. Electrical impedance tomography (EIT) has been suggested as a technique for quantifying lung inflammation in ALI. However, EIT has not been evaluated in a rodent model of ALI.
Methods:   EIT measurements were compared in ventilated Sprague–Dawley rats ( n  = 14), randomly subjected to intratracheal administration of endotoxin (LPS) or saline (control). Lung mechanics, lung weight wet/dry ratio and inflammatory markers in bronchoalveolar lavage fluid were also evaluated.
Results:   LPS caused a significant decrease in lung compliance and TLC as compared with control (−42.0%, P  = 0.04, and −27.9%, P  = 0.02, respectively). These changes were paralleled by differences in mean impedance changes as detected by EIT (Spearman's rank correlation coefficient: ρ = 0.66 and 0.73, respectively, P  < 0.01). LPS increased the lung weight wet/dry ratio (6.35 ± 0.42 vs 5.15 ± 0.07, P  = 0.003), and the bronchoalveolar lavage total WCC (8.96 ± 1.87 vs 1.16 ± 0.10 × 10⁹/L, P  = 0.002) as compared with control. The lung weight wet/dry ratio was inversely related to the mean impedance change (ρ = −0.76, P  < 0.01).
Conclusions:   This study has demonstrated for the first time that eight-electrode EIT readily tracks the inflammatory response of lung tissue in a rodent model of ALI. EIT may thus provide a promising, non-invasive technique for monitoring the time-course of ALI in rodent models, and for testing novel pharmacological strategies to counter it.     

lncRNA PACER促进脓毒症急性肺损伤炎症反应的实验研究

目的探讨lncRNA PACER对小鼠脓毒症急性肺损伤炎症反应的促进作用。 方法分离和培养急性肺损伤和健康非吸烟者的肺泡巨噬细胞,以及获取细菌脂多糖(LPS)诱导的急性肺损伤(ALI)小鼠肺组织,采用qRT-PCR方法检测lncRNA PACER的表达;过表达或敲低PACER后,ELISA方法检测THP-1和RAW264.7细胞炎性因子肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)的表达;对LPS所致ALI小鼠,尾静脉注射PACER siRNA慢病毒后,ELISA检测小鼠血清炎性因子TNF-α、IL-6的表达,HE染色观察肺组织病理学变化。 结果ALI患者肺泡巨噬细胞和ALI小鼠肺组织中lncRNA PACER表达均显著升高(P<0.01);细胞过表达PACER后,细胞炎性因子肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)的表达升高,而敲低PACER后,炎性因子TNF-α、IL-6的表达则降低(P<0.01);ALI小鼠敲低PACER后,小鼠肺组织和血清中炎性因子TNF-α、IL-6的表达均显著降低(P<0.01),肺组织损伤程度明显减弱。 结论lncRNA PACER可显著促进脓毒症急性肺损伤炎症反应,为明确lncRNA PACER作为ALI防治的靶标提供了依据。     

胰岛素对内毒素所致的急性肺损伤的防治作用

目的 观察胰岛素（insulin,ISL）对内毒素（LPS）引起的兔急性肺损伤（ALI）的预防与治疗作用,并初步探讨其作用机制。方法 将新西兰兔随机分为生理盐水（NS）对照组、LPS组、ISL+LPS组及LPS+ISL组,气管内滴注LPS建立兔ALI模型。采用微量注射泵经兔耳缘静脉滴注不同的液体,NS组和LPS组:滴注生理盐水;ISL+LPS组:滴注ISL混合液（ISL+葡萄糖+KCl）0.5 h后,再于气管内滴注LPS;LPS+ISL组:先经气管内滴注LPS 0.5 h后,再滴注ISL混合液。滴注时间持续4 h,期间监测兔平均颈总动脉压（mCAP）、血糖及血钾的变化。实验结束后处死实验动物,取肺组织观察形态学改变、测定肺湿/干质量的比值（W/D）,并分别用亚硝酸盐显色法和硫代巴比妥法测定肺组织匀浆中超氧化物歧化酶（SOD）和丙二醛（MDA）的含量及活性。结果 LPS组兔随时间 mCAP逐渐下降,实验结束时下降至(8.09±1.12)kPa,与NS组相比差异显著(P<0.05)。应用ISL预防和治疗后, mCAP下降的趋势缓慢,基本保持平稳,与LPS组相比有显著性差异（P<0.05）。LPS组兔的血糖随时间延长逐渐增高,实验结束时达峰值至(12.8±5.6)mmol/L,与NS组相比差异显著（P<0.05）。应用ISL预防和治疗后,兔的血糖随时间变化不明显,与LPS组相比差异明显（P<0.05）。实验期间各组兔的血钾基本保持平稳。形态学观察表明,LPS组肺组织水肿有点、片状出血,大量炎性细胞浸润,肺泡间隔显著增厚,肺泡腔变窄,结构消失。ISL+LPS组及LPS+ISL组的肺损伤明显减轻,肺组织结构均趋于正常;肺泡腔及支气管腔炎细胞及渗出物明显减少。与NS组相比,LPS组兔的肺W/D明显增加（P<0.05）,肺组织匀浆中SOD的活性显著降低（P<0.05）,MDA的含量显著升高（P<0.05）;而ISL+LPS组及LPS+ISL组兔的肺W/D明显减少（P<0.05）,肺组织匀浆中SOD的活性显著增加（P<0.05）,MDA的含量显著降低（P<0.05）。结论 ISL对LPS所致兔ALI具有预防与治疗的作用,其作用可能与抑制肺组织中的氧化应激作用有关。     

β-Nicotinamide adenine dinucleotide attenuates lipopolysaccharide-induced inflammatory effects in a murine model of acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) occur in approximately 200,000 patients per year. Studies indicate that lung endothelium plays a significant role in ALI. The authors' recent in vitro studies demonstrate a novel mechanism of β-nicotinamide adenine dinucleotide (β-NAD)-induced protection against gram-positive (pneumolysin, PLY) and gram-negative (lipopolysaccharide, LPS) toxin-induced lung endothelial cell (EC) barrier dysfunction. The objective of the current study was to evaluate the protective effect of β-NAD against LPS-induced ALI in mice. C57BL/6J mice were randomly divided into 4 groups: vehicle, β-NAD, LPS, and LPS/β-NAD. After surgery, mice were allowed to recover for 24 hours. Evans blue dye-albumin (EBA) was given through the internal jugular vein 2 hours prior to the termination of the experiments. Upon sacrificing the animals, bronchoalveolar lavage fluid (BALF) was collected and the lungs were harvested. β-NAD treatment significantly attenuated the inflammatory response by means of reducing the accumulation of cells and protein in BALF, blunting the parenchymal neutrophil infiltration, and preventing capillary leak. In addition, the histological examination demonstrated decreased interstitial edema in the LPS/β-NAD specimens, as compared to the LPS-only specimens. The mRNA levels of the anti-inflammatory cytokines were up-regulated in the LPS group treated with β-NAD compared to the LPS-only-treated group. β-NAD treatment down-regulated the mRNA levels of the proinflammatory cytokines. These findings suggest that β-NAD could be investigated as a therapeutic option against bacterial toxin-induced lung inflammation and ALI in mice.     

DAPK1在急性肺损伤小鼠肺组织中的表达及其作用

目的探讨死亡相关蛋白激酶1(DAPK1)在急性肺损伤小鼠肺组织中的表达及在炎症失控中的作用。方法将30只雄性C57小鼠按随机数字表法分为5组:正常对照组、LPS诱导急性肺损伤3、6、12、24 h组。应用2 mg/kg DAPK1抑制剂TC-DAPK 6预处理小鼠后,再用10 mg/kg LPS诱导小鼠肺损伤。HE染色光镜观察小鼠肺组织病理改变;免疫组化检测肺组织中DAPK1的表达和分布;应用RT-PCR和Western blot检测肺组织DAPK1和NF-κB p65的表达;ELISA检测血清炎症因子TNF-α、IL-6水平变化;Kaplan-Meier生存分析对各组小鼠存活时间进行分析。结果 LPS致伤组肺组织可见明显病理损伤改变且随时间进展加重,而DAPK1蛋白在正常对照组小鼠肺组织仅少量表达,在急性肺损伤小鼠肺组织中表达随时间进展明显增加;与正常对照组相比,LPS组肺组织DAPK1 mRNA蛋白表达水平均明显增高(P0.05),血浆炎症因子TNF-α、IL-6均明显升高(P0.05)。抑制小鼠肺DAPK1表达可明显降低LPS诱导的肺组织中DAPK1和NF-κB p65蛋白水平、血清炎症因子TNF-α、IL-6的水平(P0.05)。此外,抑制DAPK1可延长LPS致急性肺损伤小鼠的生存期(P0.01)。结论 DAPK1通过调控NF-κB炎症通路参与了LPS诱导的小鼠急性肺损伤,其可作为潜在的治疗靶点。     

1，6-二磷酸果糖对LPS急性肺损伤大鼠肺组织巨噬细胞炎症蛋白-2表达的影响

目的：观察1,6-二磷酸果糖（FDP）预先给药对内毒素性急性肺损伤（ALI）大鼠肺组织巨噬细胞炎症蛋白-2（MIP-2）表达的影响,探讨FDP可能的保护机制。方法：静脉注射脂多糖（LPS）5mg／kg,复制大鼠ALL模型。雄性SD大鼠30只随机分为3组,对照组、LPS组和LPS＋FDP组,其中LPS＋FDP组于静脉注射LPS前1h腹腔内注射FDP（250mg／kg）。3组于注射LPS或生理盐水后6h颈动脉取血测血气分析,并测定肺组织湿、干重量,计算湿／干重量比（W／D）,RT—PCR法测定肺组织MIP-2mRNA的表达;ELISA法测定肺组织TNF-a和IL-1β的含量。结果：与对照组相比,LPS组和LPS＋FDP组MIP-2mRNA表达增加,肺组织W／D、TNF-a和IL-1β含量上升（P〈0．05）;与LPS组相比,LPS＋FDP组MIP-2mRNA表达降低,肺组织W／D、TNF-a和IL-10含量降低（P〈0．05）。结论：FDP通过下调大鼠LPS诱导的MIP2表达,降低TNF-a和IL-1β的释放,减轻ALI大鼠肺部的炎症反应,保护肺组织。

Abstract：

Objective： To investigate the effects of fructose-1, 6 diphosphate （FDP） pretreatment on the expression of macrophage inflammatory protein 2 （MIP 2） in rats with acute lung injury （ALI） induced by lipopolysaccha ride （LPS）, and to explore its possible protective mechanism. Methods.. The rat models with acute lung injury were established via femoral vein injection of lipopolysaccharide （LPS, 5mg/kg）. Thirty male SD rats were randomly divided into 3 groups （n = 10） ： control group, LPS group and LPS ＋ FDP group. Rats in LPS ＋ FDP group pretreated with FDP （250 mg/kg） intrapentoneally 1 hour before LPS injection. Artery blood gases were analyzed 6 hours after LPS or normal saline administration. Samples of lung tissue were sent for the lung wet-to-dry weight ratio determination. The expression of MIP-2mRNA was detected by the method of RT-PCR; and content of TNF-a and IL-1β were detected by the method of ELISA. Results： Compared with those of control group, the expression of MIP- 2mRNA in the cytoplasm and the levels of TNF-a, IL-1β and D/W in the lung tissue were increased in LPS group and LPS＋ FDP group （P〈0. 05） ; while they were decreased in LPS ＋ FDP group compared with those of I.PS group （P〈0. 05）. Conclusions： FDP may decrease the contents of TNFa and IL-1β and alleviate the inflammation of acute lung injury in rat by down-regulating the expression of MIP-2 induced by LPS.     

Effects of MCI-186 (edaravone), a novel free radical scavenger, upon experimental atherosclerosis in apolipoprotein E-deficient mice.

BACKGROUND: Recent evidence suggests that oxidative stress may play a role in the development of atherosclerosis. MCI-186 (3-methyl-1-phenyl-1-phyrazolin-5-one, edaravone) is a novel free radical scavenger, but it remains unclear whether free radical scavengers would be effective for the prevention of the disease. METHODS AND RESULTS: Experimental atherosclerosis was induced in apolipoprotein E-deficient mice fed a high-fat diet containing 0.3% cholesterol. Mice were treated with an intraperitoneal injection of either MCI-186 1 mg/kg per day or MCI-186 10 mg/kg per day on alternate days over 4 weeks. Fatty streak lesion was suppressed by MCI-186 10 mg/kg per day administration, but not by mg/kg per day. Immunohistochemical analysis showed that macrophage and CD4+ T-cell accumulation and oxidative stress overload in the fatty streak lesion were suppressed in mice that received MCI-186 treatment. CONCLUSIONS: MCI-186 administration suppressed the development of atherosclerosis, associated with reduced expression of both immune-activated cells and oxidative stress in fatty streak plaques.     

Recombinant human erythropoietin reduces epithelial cell apoptosis and attenuates bleomycin-induced pneumonitis in mice

Background and objective:   Erythropoietin (EPO) has recently been demonstrated to have a tissue protective role by acting as an anti-apoptotic agent in various tissues, such as brain, spinal cord, heart and kidney. The purpose of this study was to determine whether human recombinant EPO reduces epithelial cell apoptosis and attenuates bleomycin-induced pneumonitis in mice.
Methods:   Bleomycin was instilled intratracheally into C57BL/6 mice. Recombinant human EPO or saline was injected intraperitoneally, daily from day 5 to day 13 after bleomycin instillation.
Results:   EPO receptor was expressed in bronchiolar and alveolar type II cells. At 14 days after instillation, the number of terminal uridine deoxynucleotidyl transferase nick end-labelled positive cells in the lung was decreased, and the histological degree of inflammation and fibrosis was attenuated in mice injected with EPO compared with controls. Expression of phosphorylated Akt and Erk, which are thought to mediate the survival signalling pathway induced by EPO, tended to be increased in lung tissues from mice treated with EPO compared with those from mice treated with saline after bleomycin instillation.
Conclusions:   As it is likely that EPO protects epithelial cells from injury and apoptosis, EPO administration could be a potential therapeutic strategy for the prevention of lung injury.     

地塞米松对急性损伤大鼠肺组织细胞凋亡及Fas基因与Fas基 …

目的 探讨细胞凋亡与急性肺损伤（ＡＬＩ）发生、发展的关系以及地塞米松在全身炎症反应及急性肺损伤中的作用机制及意义。方法 通过复制内毒素性大鼠ＡＬＩ模型,采用ＴＵＮＥＬ法、原位杂交、ＳｑＲＴ－ＰＣＲ以及免疫组化等技术观察ＡＬＩ肺组织细胞凋亡变化、Ｆａｓ基因与Ｆａｓ基因配体系统ｍＲＮＡ和蛋白质表达的改变以及地塞米松对细胞凋亡及Ｆａｓ、ＦａｓＬ表达的影响。结果 ＡＬＩ早期肺组织细胞凋亡明显增加;Ｆdispla     

Vascular endothelial growth factor in epithelial lining fluid of patients with acute respiratory distress syndrome

Background and objective:   Vascular endothelial growth factor (VEGF) is known to contribute to the development of pulmonary oedema, and has been suggested to have a protective role against lung injury. To determine the role of VEGF in acute lung injury (ALI) and ARDS, VEGF levels were measured in lung epithelial lining fluid (ELF) collected from patients with ALI/ARDS.
Methods:   Forty patients with ALI/ARDS underwent bronchoscopic microsampling to collect ELF on days 0 (onset of ALI/ARDS), 1, 3, 5, 7 and 10, unless the patient was extubated or had died. Twelve patients, who underwent bronchoscopy for examination of small, peripheral pulmonary nodules, served as controls.
Results:   The initial (day 0) levels of VEGF in ELF of the ALI/ARDS patients who survived and those who did not were 5.5 ng/mL (IQR: 2.3–19.7) and 1.7 ng/mL (IQR: 0.0–6.4), respectively. On days 0, 5, 7 and 10, the VEGF levels in ELF were significantly greater in survivors than in non-survivors ( P  < 0.05). VEGF levels on days 1 and 3 did not differ between survivors and non-survivors. There was no significant difference in ELF VEGF levels between control subjects and patients with ALI/ARDS at any time point. Lung injury score was inversely correlated with VEGF concentration in ELF ( P  < 0.001).
Conclusions:   In patients with ALI/ARDS, elevated VEGF levels in ELF may predict a better outcome. Increased production of VEGF in the injured lung may contribute to resolution of inflammation in the lung.     

一氧化碳吸入对急性肺损伤大鼠肺组织细胞凋亡的影响及其机制

目的观察吸入低浓度一氧化碳(CO)对脂多糖(LPS)致急性肺损伤(ALI)大鼠肺组织细胞凋亡的影响,探讨可能机制。方法18只雄性SD大鼠随机均分为3组。ALI组静脉滴注LPS5mg/kg,正常对照组注入生理盐水,CO吸入组在LPS诱导肺损伤后持续吸入体积分数为2.5×10-4CO。观察3h后放血处死,取肺组织,半定量逆转录聚合酶链反应(RT PCR)测定血红素氧化酶1(HO1)表达,酶联免疫吸附测定(ELISA)法检测肿瘤坏死因子α(TNFα)、白细胞介素6(IL6)和IL10的含量;化学比色法测定丙二醛(MDA)含量、髓过氧化物酶(MPO)和超氧化物歧化酶(SOD)活性;光镜观察并盲法评分比较肺组织学;流式细胞仪检测细胞凋亡。结果ALI组HO1mRNA、TNFα、IL6、IL10、MDA、MPO、SOD、细胞凋亡与正常对照组[1.002±0.004、(0.47±0.06)pg/mg蛋白、(0.49±0.12)pg/mg蛋白、(0.42±0.08)pg/mg蛋白、(0.79±0.14)nmol/mg蛋白、(6.0±1.0)U/mg蛋白、(74±7)U/mg蛋白、(0.12±0.03)%]比较差异均有统计学意义(P<0.05或<0.01),肺损伤严重。CO吸入组TNFα、IL6、MDA、MPO和细胞凋亡[(0.91±0.25)pg/mg蛋白、(0.64±0.05)pg/mg蛋白、(1.02±0.23)nmol/mg蛋白、(7.2±1.6)U/mg蛋白、(1.60±0.34)%]显著低于ALI组[(1.48±0.23)pg/mg蛋白、(1.16±0.26)pg/mg蛋白、(1.27±0.33)nmol/mg蛋白、(8.2±1.5)U/mg蛋白、(3.18±0.51)%,P均<0.05];HO1mRNA、IL10和SOD表达[5.433±0.921、(0.26±0.07)pg/mg蛋白、(60±10)U/mg蛋白]显著高于ALI组[3.081±0.823、(0.15±0.03)pg/mg蛋白、(51±7)U/mg蛋白,P均<0.05],肺损伤减轻。结论吸入CO通过调控氧化/抗氧化、促炎/抗炎反应、抑制过度细胞凋亡和上调HO1表达,可能对LPS诱导ALI起保护作用。