Automated measurement of pulmonary emphysema and small airway remodeling in cigarette smoke-exposed mice.
Automated measurement of pulmonary emphysema and small airway remodeling in cigarette smoke-exposed mice.
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DOI：
10.3791/52236
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发表时间：
2015-01-16
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影响因子：
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通讯作者：
Owen, Caroline A
中科院分区：
文献类型：
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作者：
Laucho-Contreras, Maria E;Taylor, Katherine L;Owen, Caroline A
预计到2020年，慢性阻塞性肺病将成为全球第三大常见死亡原因((1))。慢性阻塞性肺疾病的动物模型被用来识别与疾病过程有关的分子，并测试治疗COPD的新疗法的疗效。研究人员使用了许多使用不同物种的COPD模型，包括啮齿动物、豚鼠、兔子和狗((2))。然而，最广泛使用的模型是小鼠暴露在香烟烟雾中。小鼠是建立COPD模型的一个特别有用的物种，因为它们的基因组可以很容易地被操纵，以产生缺乏或过度表达单个蛋白质的动物。对暴露在香烟烟雾中的基因靶标小鼠的研究提供了关于单个分子对COPD不同肺部病理的贡献的有价值的信息((3-5))。大多数研究都集中在与肺气肿发展有关的途径上，肺气肿是COPD特有的气流阻塞的原因。然而，小气道纤维化也是人类COPD患者气流阻塞的重要原因((6))，但对烟雾暴露动物的这种损害的发病机制知之甚少。为了解决这一知识差距，该方案对烟雾暴露小鼠的肺气肿发展和小气道纤维化进行了量化。该方案使用全身暴露技术将小鼠暴露在CS中，然后测量小鼠的呼吸力学，将小鼠的肺充气到标准压力，并将肺固定在福尔马林中。然后，研究人员对肺切片进行Gill‘s染色以测量平均肺泡弦长(作为肺气肿严重程度的读数)或Masson’s三色染色以测量小气道周围细胞外基质(ECM)蛋白的沉积(作为小气道纤维化的读数)。研究分子途径在这两种肺部病变中的作用将有助于更好地了解COPD的发病机制。
COPD is projected to be the third most common cause of mortality world-wide by 2020((1)). Animal models of COPD are used to identify molecules that contribute to the disease process and to test the efficacy of novel therapies for COPD. Researchers use a number of models of COPD employing different species including rodents, guinea-pigs, rabbits, and dogs((2)). However, the most widely-used model is that in which mice are exposed to cigarette smoke. Mice are an especially useful species in which to model COPD because their genome can readily be manipulated to generate animals that are either deficient in, or over-express individual proteins. Studies of gene-targeted mice that have been exposed to cigarette smoke have provided valuable information about the contributions of individual molecules to different lung pathologies in COPD((3-5)). Most studies have focused on pathways involved in emphysema development which contributes to the airflow obstruction that is characteristic of COPD. However, small airway fibrosis also contributes significantly to airflow obstruction in human COPD patients((6)), but much less is known about the pathogenesis of this lesion in smoke-exposed animals. To address this knowledge gap, this protocol quantifies both emphysema development and small airway fibrosis in smoke-exposed mice. This protocol exposes mice to CS using a whole-body exposure technique, then measures respiratory mechanics in the mice, inflates the lungs of mice to a standard pressure, and fixes the lungs in formalin. The researcher then stains the lung sections with either Gill's stain to measure the mean alveolar chord length (as a readout of emphysema severity) or Masson's trichrome stain to measure deposition of extracellular matrix (ECM) proteins around small airways (as a readout of small airway fibrosis). Studies of the effects of molecular pathways on both of these lung pathologies will lead to a better understanding of the pathogenesis of COPD.