第二群塵螨過敏原Der p 2 誘發致敏小鼠肺組織上皮-間質轉換之研究

Investigation of epithelial-to-mesenchymal transition in lung tissues of mice sensitized by house dust mite allergen Der p 2

林席菻(Hsi-Lin Lin)

指導教授 ： 高紹軒 博士

中山醫學大學/醫學院/生化暨生物科技研究所/碩士(2013年)

摘要

氣喘是一個全球性的健康問題，在各年齡組均有分佈，尤其近年來氣喘的發生率更是節節上升，它是呼吸道常見疾病之一，會引起呼吸道過度敏感及可恢復性的呼吸道阻塞現象，經由過敏源刺激呼吸道使產生慢性氣道炎症，不但產生了病理學變化如：呼吸道平滑肌功能喪失與增生、發炎及氣道壁增厚導致肺臟結構及功能上有異常，進而發生上皮-間質轉化Epithelial-to-mesenchymal transition（EMT）使得肺臟纖維化。
歐洲室塵蟎第二群過敏原(Dermatophagoides pteronyssinus group 2 allergen, Der p 2)是主要塵蟎過敏原之一，研究有顯示經由過敏原刺激後從急性發炎轉變成慢性發炎不但肺臟裡炎症細胞分部會有所改變、也會誘發黏液之產生，趨使呼吸道上皮之改變，使得細胞migration，進而產生上皮-間質轉化Epithelial-to-mesenchymal transition（EMT），影響在細胞內分子的表現量和細胞的內的分布。本研究利用HE stain觀察過敏原對肺臟病理學方面的變化，發現過敏原刺激之後血管擴張、通透性增加使得肺臟紅血球數量上升，肺泡壁也明顯增厚，但是對於炎症細胞分佈從實驗中結果看來並無明顯改變，還是以巨噬細胞為主，少數淋巴球；接著利用的特殊染色Silver、Masson來觀察肺臟纖維化及Mucin來觀察支氣管黏液產生之現象，發現肺臟之纖維化現象並無明顯變化，也並無黏液之產生；再利用免疫化學染色法觀察上皮-間質轉化Epithelial-to-mesenchymal transition（EMT）相關分子之表現，發現Vimentin會增強、E-cadherin表現量下降和ß-catenin表現會增強。本研究我們利用Der p 2來誘發的老鼠的過敏反應其結果顯示會促使血管不等程度擴張及肺泡壁增厚，在發炎反應方面，炎症細胞以巨噬細胞和淋巴球為主，在纖維化及黏液產生並無明顯的變化，但對於上皮-間質轉化Epithelial-to-mesenchymal transitio（EMT）相關分子之表現包含E-cadherin, vimentin and ß-catenin方面我們發現Der p 2會誘發老鼠肺臟上皮-間質轉化Epithelial-to- mesenchymaltransition（EMT）現象的產生 。

關鍵字

上皮-間質轉化

並列摘要

Asthma is a chronic airway diseases affecting globe population and distributing in every age. Prevalence of asthma has been dramatically increasing in Taiwan and developed nations over the past decades. Allergic asthma is the major type of the respiratory disease. Its major clinical properties of airway include hypersensitiveness, chronic inflammation, dysfunction and proliferation of smooth muscle cell, and fibrosis. Previous studies have been demonstrated that epithelial-to-mesenchymal transition (EMT) plays important roles in pathogenesis of asthma; however, roles of aeroallergens in developing airway EMT remain unclear.
House dust mite (HDM) is the major cause of asthma. Literature has shown that HDM allergens are able to induce chronic airway inflammation, increase mucus production, enhance epithelial cell migration, and EMT of respiratory epithelium. Der p 2 is a major allergen derived from a HDM Dermatophagoides pteronyssinus. In the present study, we aimed to investigate the roles of Der p 2 in EMT on lung tissue. After a 10-day consecutive sensitization with recombinant Der p 2 (rDer p 2), lung tissues from sensitized Balb/c mice were obtained and fixed. The fixed tissues were sectioned and individually reacted with hematoxylin and eosin (HE) stain, mucicarmine stain, Mason’s trichrome stain, silver stain, and immunohistochemical (IHC) stain. Our results revealed that the short rDer p 2 sensitization enlarged blood vessels and enhanced their permeability, resulting in increased red blood cells (RBC) in lung tissues. In contrast to increased RBC, numbers of invaded inflammatory cells in lung tissues were insignificantly changed in rDer p 2-sensitized mice as compared to sham control. Fibrosis and mucin production in lung tissues were insignificantly altered in rDer p 2-sensitized mice as compared to sham control by using Masson staining and silver staining. Interestingly, IHC stains using specific antibodies showed that levels of mesenchymal markers vimentin and

並列關鍵字

Epithelial-to-mesenchymal transition（EMT）

參考文獻

1.Nawijn, M.C., et al., E-cadherin: gatekeeper of airway mucosa and allergic sensitization. Trends Immunol, 2011. 32(6): p. 248-55.

2.Elias, J.A., et al., Airway remodeling in asthma. J Clin Invest, 1999. 104(8): p. 1001-6.

3.Johnson, J.R., et al., Chronic respiratory aeroallergen exposure in mice induces epithelial-mesenchymal transition in the large airways. PLoS One, 2011. 6(1): p. e16175.

4.Heijink, I.H., et al., House dust mite-promoted epithelial-to-mesenchymal transition in human bronchial epithelium. Am J Respir Cell Mol Biol, 2010. 42(1): p. 69-79.

5.Holgate, S.T., The airway epithelium is central to the pathogenesis of asthma. Allergol Int, 2008. 57(1): p. 1-10.