Department of Medical Biology, Institute of Rural Health, Lublin, Poland.
Department of Medical Biology, Institute of Rural Health, Lublin, Poland; Department of Functional Anatomy and Cytobiology, Maria Curie-Skłodowska University, Lublin, Poland.
Ecotoxicol Environ Saf. 2020 May;194:110416. doi: 10.1016/j.ecoenv.2020.110416. Epub 2020 Mar 5.
Pantoea agglomerans is gram-negative bacteria widely distributed in nature. It predominates in inhalable dust from grain, herbs, and flax, and was identified as the most important cause of hypersensitivity pneumonitis (HP) in eastern Poland. To better understand the molecular mechanism of HP development studies focused on the interactions between P. agglomerans and alveolar epithelial cells as well as lung tissue with particular emphasis on the epithelial-mesenchymal transition (EMT). The studies were conducted on human normal lung epithelial NL20 cells and mice strain C57BL/6J. Cells and mice underwent chronic exposure to saline extract of P. agglomerans (SE-PA). Morphological changes were evaluated under light microscopy, the concentration of fibrosis markers was examined by the ELISA method, while the expression of genes involved in EMT was evaluated by RealTime PCR. During incubation with SE-PA epithelial cells underwent conversion and assumed fibroblast phenotype characterized by a decrease in epithelial cells markers (CDH1, CLDN1, JUP) and increase in mesenchymal cells markers (FN1, VIM, CDH2). Mice lungs collected after 14 days of SE-PA treatment revealed inflammation with marked lymphocytes infiltration. The intensified inflammatory process accompanied by increased proliferation of fibrous connective tissue was noted in mice lungs after 28 days of SE-PA exposure. Histological changes correlated with an increase of fibrosis markers (hydroxyproline, collagens), downregulation of epithelial markers (Cdh1, Cldn1, Jup, Ocln) and upregulation of myofibroblasts markers (Acta2, Cdh2, Fn1, Vim). Obtained results revealed SE-PA ability to induce EMT in human lung epithelial cells and mice lung tissue, with the scale of changes proportional to the time of treatment.
成团泛菌是一种广泛分布于自然界中的革兰氏阴性细菌。它主要存在于谷物、草药和亚麻的可吸入粉尘中，被确定为波兰东部最重要的过敏性肺炎（HP）病因。为了更好地了解 HP 发展的分子机制，研究集中在成团泛菌与肺泡上皮细胞以及肺组织之间的相互作用上，特别强调上皮-间充质转化（EMT）。这些研究是在人正常肺上皮 NL20 细胞和 C57BL/6J 小鼠品系上进行的。细胞和小鼠经历了成团泛菌盐水提取物（SE-PA）的慢性暴露。在光镜下评估形态变化，通过 ELISA 法检查纤维化标志物的浓度，同时通过 RealTime PCR 评估参与 EMT 的基因的表达。在与 SE-PA 孵育期间，上皮细胞发生转化并呈现出成纤维细胞表型，特征是上皮细胞标志物（CDH1、CLDN1、JUP）减少和间充质细胞标志物（FN1、VIM、CDH2）增加。在 SE-PA 处理后 14 天收集的小鼠肺中，发现有明显淋巴细胞浸润的炎症。在 SE-PA 暴露 28 天后，小鼠肺部的炎症过程加剧，伴有纤维结缔组织增生。组织学变化与纤维化标志物（羟脯氨酸、胶原蛋白）的增加、上皮标志物（Cdh1、Cldn1、Jup、Ocln）的下调和肌成纤维细胞标志物（Acta2、Cdh2、Fn1、Vim）的上调相关。这些结果表明 SE-PA 能够诱导人肺上皮细胞和小鼠肺组织发生 EMT，其变化的规模与治疗时间成正比。
