Organizing empyema induced in mice by Streptococcus pneumoniae: effects of plasminogen activator inhibitor-1 deficiency.
Organizing empyema induced in mice by Streptococcus pneumoniae: effects of plasminogen activator inhibitor-1 deficiency.
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DOI：
10.1186/s40169-016-0097-2
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发表时间：
2016-12
影响因子：
10.6
通讯作者：
Idell S
中科院分区：
文献类型：
--
作者：
Tucker TA;Jeffers A;Boren J;Quaid B;Owens S;Koenig KB;Tsukasaki Y;Florova G;Komissarov AA;Ikebe M;Idell S
在美国和英国，每年约有6.5万名患者受到胸膜感染的影响。在这种和其他形式的胸膜损伤中，间皮细胞(PMC)经历了一个称为间皮(MESO)间充质转化(MT)的过程，通过这个过程，PMC获得了促纤维化的表型，α-平滑肌肌动蛋白(α-SMA)和基质蛋白的表达增加。因此，MesoMT有助于胸膜组织的纤维化和肺限制。目前的小鼠脓胸模型的特点是早期死亡，限制了对胸膜组织的发病机制和感染后促进MesoMT的机制的分析。通过胸腔注射肺炎链球菌(D39，3×107-5×109CFU)，在C57BL/6/J小鼠体内建立了一种新的小鼠脓胸模型，以使使用转基因动物成为可能。CT扫描和肺功能测试用于描述机化性脓胸的生理后果。采用组织学、免疫组织化学和免疫荧光等方法评价胸膜损伤程度。采用酶联免疫吸附试验、细胞因子芯片和免疫印迹法检测胸腔积液介质和胸腔积液中的MesoMT标志物。脓胸的诱导是通过鼻腔或胸膜腔内注射肺炎链球菌来完成的。鼻腔给药损害了肺顺应性(P<0.05)，肺容量减少了7天(P<0.05)，但未能可靠地诱发脓胸，其特征是死亡率令人无法接受。胸膜腔内注射肺炎链球菌可引起24小时内脓胸，并伴有肺受限和胸膜纤维化，持续时间长达14天。肺炎链球菌感染小鼠内脏胸膜中的MesoMT标志物增加。感染后第7天，胸腔灌洗液中KC、IL-17A、MIP-1β、MCP-1、PGE_2和纤溶酶活性均升高。PAI-1−/−小鼠在4天内死亡，胸膜炎症加重，PGE_2水平高于WT小鼠。用uPA和纤溶酶诱导原代PMCs产生PGE2，并诱导MesoMT标志物。据我们所知，这是第一个亚急性组织性脓胸的小鼠模型。该模型可以用来识别像PAI-1缺乏这样的因素，改变结果，并剖析它们对胸膜组织、皮肤形成和肺限制的贡献。
Pleural infection affects about 65,000 patients annually in the US and UK. In this and other forms of pleural injury, mesothelial cells (PMCs) undergo a process called mesothelial (Meso) mesenchymal transition (MT), by which PMCs acquire a profibrogenic phenotype with increased expression of α-smooth muscle actin (α-SMA) and matrix proteins. MesoMT thereby contributes to pleural organization with fibrosis and lung restriction. Current murine empyema models are characterized by early mortality, limiting analysis of the pathogenesis of pleural organization and mechanisms that promote MesoMT after infection. A new murine empyema model was generated in C57BL/6 J mice by intrapleural delivery of Streptococcus pneumoniae (D39, 3 × 107–5 × 109 cfu) to enable use of genetically manipulated animals. CT-scanning and pulmonary function tests were used to characterize the physiologic consequences of organizing empyema. Histology, immunohistochemistry, and immunofluorescence were used to assess pleural injury. ELISA, cytokine array and western analyses were used to assess pleural fluid mediators and markers of MesoMT in primary PMCs. Induction of empyema was done through intranasal or intrapleural delivery of S. pneumoniae. Intranasal delivery impaired lung compliance (p < 0.05) and reduced lung volume (p < 0.05) by 7 days, but failed to reliably induce empyema and was characterized by unacceptable mortality. Intrapleural delivery of S. pneumoniae induced empyema by 24 h with lung restriction and development of pleural fibrosis which persisted for up to 14 days. Markers of MesoMT were increased in the visceral pleura of S. pneumoniae infected mice. KC, IL-17A, MIP-1β, MCP-1, PGE2 and plasmin activity were increased in pleural lavage of infected mice at 7 days. PAI-1−/− mice died within 4 days, had increased pleural inflammation and higher PGE2 levels than WT mice. PGE2 was induced in primary PMCs by uPA and plasmin and induced markers of MesoMT. To our knowledge, this is the first murine model of subacute, organizing empyema. The model can be used to identify factors that, like PAI-1 deficiency, alter outcomes and dissect their contribution to pleural organization, rind formation and lung restriction.