Effects of pulmonary surfactant on macrophage migration: Suppression of chemokinesis by surfactant phospholipid and enhancement of chemotaxis by surfactant protein

Abstract We fractionated the bronchoalveolar lavage fluid (BALF) from normal rabbit lungs into several fractions by high speed centrifugation and ethanol-ether extraction. Random migration, chemokinesis and chemotaxis of freshly harvested alveolar macrophages (AM), 24 h cultured AM, and peritoneal exudate cells (PEC) were assayed in vitro using a modified, under agarose method and a blind well chemotactic chamber method. Freshly harvested AM demonstrated little random migration compared with PEC. However, when freshly harvested AM were pre-incubated in surfactant free medium for 24 h, the cells showed the same rate of migration as PEC. The increased migration of the 24 h cultured AM was partially suppressed by the presence of all BALF fractions containing high proportions of phospholipid. The inhibition by Fr-L (a fraction enriched in phospholipids) was reversed by normal serum, but not by heat-inactivated serum, cholesterol, synthetic dipalmitoyl phosphatidyl choline, or indomethacin. Fr-L markedly suppressed macrophage chemokinesis but did not affect on macrophage chemotaxis. Alternatively, Fr-P, a delipidated preparation of surfactant consisting mainly of protein, had no effect on macrophage chemokinesis but increased the chemotaxis of PEC to zymosan-activated serum. We conclude that surfactant phospholipid suppresses AM migration, while surfactant protein increases macrophage chemotaxis.     

Pulmonary stem cells and the induction of tissue regeneration in the treatment of emphysema

A common feature of lung disorders with poor treatment options, including emphysema, is a failure to initiate a repair process of the alveolar epithelium. Several putative stem cell niches in the lung thought to be involved in lung homeostasis have been described. Apparently, under pathophysiological conditions these resident progenitor cells are unable to recover damaged alveolar epithelium, in particular in emphysema. The potential therapeutic effect of retinoic acid receptor agonists on various resident lung progenitor cells is reviewed.     

Elevated serum surfactant protein A and D in pulmonary alveolar microlithiasis

Pulmonary alveolar microlithiasis (PAM) is a rare disease characterized by widespread localization of calcispherites in the alveolar spaces. The authors report two cases of PAM, with markedly elevated sera concentrations of surfactant protein-A and surfactant protein-D, which showed a tendency to increase as the disease progressed. Therefore, surfactant protein-A and surfactant protein-D may function as serum markers to monitor the disease activity and progression of PAM.     

Bilirubin influence on oxidative lung damage and surfactant surface tension properties

To study the hypothesis that hyperbilirubinemia might reduce in vivo oxidative lung damage while also diminishing lung surfactant surface tension properties during acute lung injury, we performed a randomized study in a rabbit model of acute lung injury. Twenty rabbits were randomized to receive bilirubin or saline intravenously. Acute lung injury was induced by lung lavages with saline. Lung tissue oxidation was evaluated by measuring total hydroperoxide (TH), advanced oxidation protein products (AOPP), and protein carbonyls (PC) in bronchial aspirate (BA) samples. Surface surfactant activity was studied in BA samples using a capillary surfactometer. Bilirubin BA concentration increased in bilirubin-treated rabbits, while it remained undetectable in controls. A similar increase in TH, AOPP, and PC bronchial aspirate concentrations was found in both the study and control groups, while surfactant surface activity was lower in the bilirubin than in the control group. We conclude that during hyperbilirubinemia, bilirubin enters the lung tissue, where it can be detected in BA fluid. Bilirubin is not effective as an antioxidant agent and exerts a detrimental effect on lung surfactant surface tension properties. These findings may have relevance to the management of premature neonates suffering from respiratory distress syndrome and hyperbilirubinemia.     

Genotoxic changes in the pulmonary alveolar macrophages of mice, rats and hamsters treated with tobacco smoke

To determine whether tobacco smoke (TS) is genotoxic for lung tissue macrophages (pulmonary alveolar macrophages, PAM) as a general result of its inhalatory action BD6 rats, Syrian golden hamsters and BDF1 (C57BlxDBA2) mice were subjected to wholebody exposure for 90 or 60 min daily (600 cm³ mainstream smoke in 16-1 glass chamber, 9 or 6 exposures of 15 min each, respectively), for different periods ranging up to 30 days. A significant enhancement of the frequency of polynucleated macrophages (BiN PAM) was observed in all animal species after more than 10-days of repeated exposure to TS. The increased level of BiN PAM (the number of bi- + poly-nucleated PAM) correlates with the duration of exposure to TS: on day 20 after the start of inhalation, more than 25 of mice PAM were polynucleated, while on day 30 this applied to approximately 50. Furthermore, a highly significant increase in the level of micronucleated PAM (MN PAM) was also established after 10 days TS treatment of mice and persisted to the end of these examinations. TS was effective in enhancing the micronucleated and polynucleated PAM levels in hamsters irrespective of their sex, as it was in male BD6 rats aged 2 or 11 months. It appears that TS induces a more pronounced elevation of polynucleated PAM frequency in rats than in hamsters and mice. These data suggest that inhaled TS is genotoxic in alveolar macrophages in all exposed species of laboratory animals. An attempt was made to trace the possible clastogenic effect of a single i.p. administration of cyclophosphamide (CP, 15 mg/kg) in mice simultaneously in bone marrow and in PAM. A definite clastogenic effect in bone marrow 24 h and 48 h after CP injection and a total absence of changes in PAM from the lungs during the 15-day period after clastogen exposure were established. These data may support the hypothesis of local production of PAM in the lung from their proliferative precursor. The results provide evidence that PAM in laboratory animals are a sensitive and useful target for assessing harmful effects associated with environmental chemical factors that can be inhaled, including TS.Supported by the Ministry of Education and Sciences of Bulgaria (grant no. L412)     

脂多糖对大鼠肺泡巨噬细胞分泌一氧化氮和氧化应激的影响

目的探讨细菌内毒素脂多糖（LPS）对SD大鼠肺泡巨噬细胞产生一氧化氮（NO）和氧化应激的影响。方法采用支气管肺泡灌洗和细胞差速贴壁的方法分离大鼠肺泡巨噬细胞（AM）,分别测定AM培养上清液NO含量、一氧化氮合酶（NOS）活性、丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性。结果在5,10,20,50mg/LLPS分别干预下,大鼠AM培养上清液NO含量、NOS活性和MDA含量均显著升高,SOD活性显著降低,并且具有浓度依赖性。结论LPS促进大鼠AM分泌NO,并诱导AM脂质过氧化损伤,这可能是内毒素诱发肺部炎症反应不易控制和急性肺损伤的机制之一。     

Natural surfactant combined with beclomethasone decreases oxidative lung injury in the preterm lamb

We performed a randomized study in preterm lambs to assess the hypothesis that the treatment with natural surfactant combined with beclomethasone might decrease pulmonary oxidative stress in an animal model of respiratory distress syndrome (RDS). Animals received 200 mg/kg of porcine natural surfactant or 200 mg/kg of natural surfactant combined with 400 or 800 µg/kg of beclomethasone. Lung tissue oxidation was studied by measuring total hydroperoxide (TH), advanced oxidation protein products (AOPP), and non‐protein bound iron (NPBI) in bronchial aspirate samples. In addition, lung mechanics was evaluated. TH was lower in the groups treated with surfactant plus 400 or 800 µg/kg of beclomethasone than in the surfactant group; AOPP was lower in the group treated with surfactant plus 800 µg/kg of beclomethasone than in the other groups; NPBI was similar in all groups. Surfactant treatment was followed by a sustained improvement of tidal volume (TV) and airway resistance, while dynamic compliance did not vary. However, the mean airway pressure needed to obtain similar values of TV was lower in the group treated with surfactant plus 800 µg/kg of beclomethasone than in other groups. We concluded that natural surfactant combined with beclomethasone at 800 µg/kg is effective in reducing the oxidative lung stress and improving the respiratory function in an animal model of RDS. Pediatr Pulmonol. 2009; 44:1159–1167. © 2009 Wiley‐Liss, Inc.     

The proteinase–antiproteinase theory of emphysema: A speculative analysis of recent advances into the pathogenesis of emphysema

This review concerns the reasons why only an estimated 10–15% of patients with alpha-1-antitrypsin (A1AT) deficiency develop the destructive lung disease known as emphysema. The arguments presented revolve around the proteinase-antiproteinase balance in the 'microenvironment' of the epithelial space of the lung. Attention is focused on the balance between destructive enzymes such as neutrophil elastase and protective proteins such as A1AT, secretory leucocyte proteinase inhibitor (SLPI), human elastase inhibitor (HEI) and elafin. When neutrophil elastase is already attached to the elastin fibres the smaller molecules SLPI and elafin appear to be better inhibitors of this enzyme than larger inhibitors such as A1AT and HEI. Furthermore, SLPI and elafin may provide the first line of defence against proteinase attack from neutrophil elastase. In trying to explain the variability in the clinical expression of A1AT-deficiency and the development of emphysema, the importance of changes to A1AT, SLPI and elafin molecules induced by smoking and/or oxygen free radicals has been considered. It is possible that emphysema only develops in patients who have SLPI/elafin deficiency as well as A1AT deficiency.     

基质金属蛋白酶在阻塞性肺气肿大鼠模型中的表达及部分细胞因子的水平

目的　观察基质金属蛋白酶 2 (MMP 2 )和MMP 9在阻塞性肺气肿大鼠模型中的表达及白细胞介素 (IL) 1 0和肿瘤坏死因子 (TNF)α的水平。方法　 2 4只雄性Wistar大鼠随机分为 2组 ,每组1 2只 ,阻塞性肺气肿模型组 :将大鼠置于自制有机玻璃染毒箱内进行被动吸烟 (金键牌香烟 ) ,每天 2次 ,每次 1 6支 ,持续 30min ,2次之间间隔 4h ,连续 75d。健康对照组大鼠 2级实验动物房内室温常规饲养。 2组大鼠行第 0 3秒钟用力呼气容积 (FEV0 3)、FEV0 3/用力肺活量 (FVC)、功能残气量 (FRC)的测定。大鼠处死后 ,行支气管肺泡灌洗 ,测支气管肺泡灌洗液 (BALF)中白细胞总数和各分类细胞数、MMP 2和MMP 9的活性及IL 1 0和TNFα的含量。免疫组化法检测支气管、肺组织中MMP 2和MMP 9的表达及其蛋白相对含量。Weigert弹力纤维染色观察弹力纤维的变化。结果　阻塞性肺气肿模型组大鼠支气管黏膜上皮大片脱落 ,管壁及周围大量的单核细胞和淋巴细胞浸润 ;肺泡结构紊乱 ,肺泡壁变薄或断裂 ,肺泡弹性减弱 ,呈囊状扩张 ,肺泡腔扩大 ,部分融合成肺大疱。与健康对照组相比 ,阻塞性肺气肿模型组大鼠FEV0 3[(5 1 2± 0 42 )ml]、(FEV0 3/FVC)× 1 0 0 % [(71 1 5± 9 84) ]显著降低 ,FRC[(7 2 2± 2 1 8)ml]显著增加 (P值均 <     

Different Doses of Lipopolysaccharides Regulate the Lung Inflammation of Asthmatic Mice via TLR4 Pathway in Alveolar Macrophages

Allergic asthma is a complicated genetic disorder caused by interaction of the acquired and innate immune responses. Acquired immune responses to protein antigens could induce type 2 T lymphocyte-driven responses and result in atopic asthma. Recent studies demonstrated that endotoxin, LPS and air pollution-induced innate immunity induce asthma through Toll-like receptors (TLR). However, the definite mechanism of LPS-induced asthma is still not known. Here, we investigated the effects of different doses of LPS in a mouse model of allergic asthma to define the molecular mechanism of LPS-induced asthma. We found that low doses of LPS in OVA induced significant inflammatory infiltration in lung tissue of asthmatic mice. Histologic studies demonstrated that lungs of these asthmatic mice were characterized by the recruitment of both eosinophils and neutrophils, increased airway mucus secretion and the elevated levels of Th2 cytokines. A high dose of LPS in OVA can induce a Th1 associated response, histologically characterized by neutrophil recruitment, the absence of airway mucus secretion and an increase of IFN-γ production. Regardless of high or low dose of LPS, TLR4 in alveolar macrophages (AM) was up-regulated in lungs of asthmatic mice. Our data demonstrated that the dose of LPS exposure determines the type of inflammatory response and a low dose of LPS together with OVA augments the antigen-induced lung inflammation in asthma. This study demonstrates that the TLR4 signaling pathway plays a vital role in the development of asthma and indicates the tight connection between endotoxin exposure and asthma prevalence in the clinic.     

Role of melatonin in regulating matrix metalloproteinase-9 via tissue inhibitors of metalloproteinase-1 during protection against endometriosis

Abstract:  Endometriosis is a gynecological disease of women and plausibly regulated by matrix metalloproteinases (MMPs). However, mechanisms of alterations in MMPs during endometriosis remain unclear. Human endometriotic tissues possessing varying degrees of severity were examined for expression of MMPs and tissue inhibitors of metalloproteinase (TIMP)-1. In addition, endometriosis was generated in mice and endometriotic tissues were tested for MMP-9 activity. Results show significant upregulation of secreted and synthesized proMMP-9 activity with duration and severity of endometriosis. Along with upregulation of activity, the expression of proMMP-9 was found increased while TIMP-1 expression followed an inverse trend. The effect of melatonin, a major secretory product of the pineal gland, on endometriosis was examined in preventive and therapeutic models in mice. The results show that melatonin arrested lipid peroxidation and protein oxidation and downregulated proMMP-9 activity and expression in a time and dose-dependent manner while protecting and regressing peritoneal endometriosis. Moreover, the attenuated activity and expression of proMMP-9 were associated with subsequent elevation in the expression of TIMP-1. Our study reveals for the first time the role of melatonin in arresting peritoneal endometriosis in mice and a novel marker, expression ratio of proMMP-9 versus TIMP-1, was identified for assessing severity and progression of endometriosis.     

肺纤维化合并肺气肿的临床研究进展

特发性肺纤维化（IPF）和肺气肿在影像学、病理生理、治疗及预后等方面各不相同,是两种疾病。然而,部分患者影像学表现同时存在肺纤维化和肺气肿,被称为肺纤维化合并肺气肿（CPFE）。CPFE的表现与单纯的肺气肿或IPF不同,因此被认为是一种独立的疾病,且越来越受到关注。本文对CPFE的病因与发病机制、临床表现、诊断、并发症、治疗和预后等方面进行了综述。     

Humic acid enhances cigarette smoke-induced lung emphysema in mice and IL-8 release of human monocytes

Tobacco smoke is the main factor in the etiology of lung emphysema. Generally prolonged, substantial exposure is required to develop the disease. Humic acid is a major component of cigarette smoke that accumulates in smokers’ lungs over time and induces tissue damage.

Objectives

To investigate whether humic acid pre-loading potentiates the development of cigarette smoke-induced lung emphysema in mice and increases IL-8 release by human monocytes.

Methods

C57BL/6J mice received humic acid or aqueous vehicle by tracheal installation on day 0 and day 7. From day 21 to day 84, the mice were exposed to cigarette smoke or clean air for 5 days/week. Twenty-four hours after the last exposure we determined leukocytes in lung lavage, heart hypertrophy and alveolar wall destruction. Human monocytes were incubated with cigarette smoke extract (CSE), humic acid or the combination overnight.

Results

Humic acid nor cigarette smoke caused alveolar wall destruction within two months. Interestingly, the combination did induce lung emphysema. Humic acid, cigarette smoke or the combination did not change leukocyte types and numbers in lung lavage fluid, but the combination caused peribronchiolar and perivascular lymphocyte infiltration. Humic acid treatment resulted in a high proportion of alveolar macrophages heavily loaded with intracellular granula. Humic acid also induces the release of IL-8 from human monocytes and enhances the CSE-induced IL-8 release.

Conclusions

Humic acid deposition in the lungs potentiates the development of cigarette smoke-induced interstitial inflammation and lung emphysema. Moreover, humic acid promotes IL-8 release from human monocytes. Since humic acid accumulates steadily in the lungs of smokers, this may provide an explanation for the natural history on late onset of this disease. The model described here offers a novel way to study emphysema and may direct the search for new therapeutic approaches.     

Alveolar Macrophage Phenotype and Compartmentalization Drive Different Pulmonary Changes in Mouse Strains Exposed to Cigarette Smoke

Abstract

COPD can manifest itself with different clinical phenotypes characterized by different disease progression and response to therapy. Although a remarkable number of studies have been carried out, little is known about the mechanisms underlying phenotypes that could guide the development of viable future therapies. Several murine strains mirror some human phenotypes after smoke exposure. It was of interest to investigate in these strains whether different pattern of activation of macrophages, and their distribution in lungs, is associated to changes characterizing different phenotypes. We chose C57Bl/6, and Lck deficient mice, which show significant emphysema, DBA/2 mice that develop changes similar to those of “pulmonary fibrosis/emphysema syndrome”, p66Shc ko mice that develop bronchiolitis with fibrosis but not emphysema, and finally ICR mice that do not develop changes at 7?months after smoke exposure. Unlike other strains, ICR mice show very few activated macrophages (Mac-3 positive) mostly negative to M1 or M2 markers. On the other hand, a large population of M1 macrophages predominates in the lung periphery of DBA/2, C57Bl/6 and in Lck deficient mice, where emphysema is more evident. M2 macrophages are mainly observed in subpleural and intraparenchymal areas of DBA/2 mice and around bronchioles of p66Shc ko mice where fibrotic changes are present. We observed slight but significant differences in mRNA expression of iNOS, ECF-L, arginase 1, IL-4, IL-13 and TGF-β between air- and smoke-exposed mice. These differences together with the different compartmentalization of macrophages may offer an explanation for the diversity of lesions and their distribution that we observed among the strains.     

CD4+白细胞介素-17+辅助性T细胞对香烟暴露小鼠肺部炎症及肺气肿的作用

Objective To evaluate the expression and the role of Th 17 in cigarette smoke-induced lung inflammation and emphysema in mice.Methods Forty male BALB/c mice were randomly divided into 4 groups, including a control group C12, a control group C24, a smoke-exposure 12 week group (S12) and a smoke-exposure 24 week group S24 (n = 10 each).Morphological changes were evaluated by mean linear intercepts and destructive index (DI).The proportion of CD4+ IL-17 + Th17, CD4+ IFN-γ+ Th1, CD4+ IL-17 +IFN-γ+ T( Th17/ Th1 ), CD8+ IFN-γ+ Tc1, CD8+ IL-21R + and CD4+ IL-17 + IL-21 + T cells in lungs of mice was determined by flow cytometry.The mRNA expressions of RORγt and IL-17 were evaluated by real-time PCR.Results Mean linear intercepts and DI were significantly higher in S12 and S24 groups [(39 ± 4)μm, (47 ±7) μm], (39.1 ± 1.6, 45.2 ±3.1 ) as compared to C12[(32 ±4) μm,28.2 ± 1.6] and C24groups [(33 ± 3 ) μm ,28.9 ± 2.1], all P ＜ O.05.The percentage of Th17 of S12 and S24 groups [(3.3 ±1.1 )%, (7.2 ±2.2)%] was significantly increased as compared with that of C12 and C24 groups [( 1.8± 0.8) %, (2.0 ± 0.6) %], all P ＜ 0.05.The mRNA levels of RORγt [( 25 ± 4), ( 35 ± 3 )] and IL-17 [(26 ± 3), (36 ± 3 )] in S12 and S24 groups were higher than in C12 [(10 ± 5 ), (13 ± 5 )] and C24 groups [( 11 ± 7 ), (8 ± 6)], all P ＜ 0.05.The percentage of Th 1, Th17/Th1 and Tc1 cells of S12 and S24 groups [(10.0 ±3.7)%, (26.2 ±6.0)%], [(0.61 ±0.30)%, (1.82 ±0.52)%], [(17.0±4.5 ) %, ( 26.8 ± 8.5 ) %] was significantly increased as compared with that of C12 [( 3.8 ± 1.7 ) %,(0.27±0.17)%, (4.8 ±1.9)%] and C24 groups [(4.2±1.3)%, (0.28±0.11)%, (5.2±1.0)%], all P＜0.05.Moreover, the frequency of Th17 cells had a positive correlation with Th1, Tc1 cells and emphysematous lesions ( r =0.519 - 0.797, all P ＜ 0.01 ).In addition, a positive correlation between Th17/Th1 cells and emphysematous lesions was also found (r =0.742, 0.802, all P ＜0.01 ).The percentage of CD4+ IL-17+ IL-21 +T cells was significantly increased in S12 and S24 groups [(0.19 ±0.04) %, (0.55 ± 0.24) %] compared to controls [(0.07 ± 0.03 ) %, (0.08 ± 0.03 ) %], all P ＜ 0.05.Meanwhile, as compared with that of the controls [( 1.22 ± 0.31 ), ( 1.34 ± 0.18 )], the percentage of CD8+ IL-21 R + T cells was also increased in SI 2 and S24 groups [( 2.94 ± 1.26 ), (4.12 ± 2.26 )], but there were no differences among smoke-exposure groups ( P ＞0.05 ).The frequency of CD4+ IL-17 + IL-21 + T cells had a positive correlation with Th 1, Tc1 cells and emphysematous lesions (r = 0.694 -0.754, all P ＜0.05).And the frequency of CD8+ IL-21R+ T cells also had a positive correlation with emphysematous lesions ( r = 0.516, 0.725, all P ＜ 0.05).Conclusions Cigarette smoke increased the expression and the activity of Th17 in mice.Th17 may play a potential (active) role in the development of lung inflammation through IL-21/IL-21R pathway.     

普伐他汀对培养巨噬细胞表达基质金属蛋白酶活性的影响

目的　探讨普伐他汀对基质金属蛋白酶 (matrixmetalloproteinases ,MMPs)活性的影响及其与粥样斑块稳定性的关系。方法　从SD大鼠腹腔取巨噬细胞体外培养 ,接种于 2 4孔板中 ,逐孔加入普伐他汀 ,终浓度分别为 10 - 3、10 - 4及 10 - 5mol L ,每种浓度 3孔 ,分别在 2 4、4 8及 72h收集上清液 ,未加药孔为空白对照 ,采用酶谱分析法测量上清液中MMPs的活性。结果　巨噬细胞上清液中有MMP 2及MMP 9的活性表达 ,以 2 4h时活性最强。普伐他汀可以降低其活性 ,随着浓度的增加 ,抑制作用越明显。结论　普伐他汀可以使巨噬细胞产生的MMPs活性降低 ,可能使纤维帽中胶原的降解减少 ,从而增加粥样斑块的稳定性