Kitsiouli Eirini, Antoniou Georgia, Gotzou Helen, Karagiannopoulos Michalis, Basagiannis Dimitris, Christoforidis Savvas, Nakos George, Lekka Marilena E
Laboratory of Biochemistry, Chemistry Department, School of Science, University of Ioannina, Greece.
Institute of Molecular Biology and Biotechnology, Biomedical Research, Foundation for Research and Technology, Ioannina, Greece; Laboratory of Biological Chemistry, Medical School, University of Ioannina, Greece.
Biochim Biophys Acta. 2015 Jul;1852(7):1288-97. doi: 10.1016/j.bbadis.2015.03.008. Epub 2015 Mar 17.
Azithromycin is a member of macrolides, utilized in the treatment of infections. Independently, these antibiotics also possess anti-inflammatory and immunomodulatory properties. Phospholipase A2 isotypes, which are implicated in the pathophysiology of inflammatory lung disorders, are produced by alveolar macrophages and other lung cells during inflammatory response and can promote lung injury by destructing lung surfactant. The aim of the study was to investigate whether in lung cells azithromycin can inhibit secretory and cytosolic phospholipases A2, (sPLA2) and (cPLA2), respectively, which are induced by an inflammatory trigger. In this respect, we studied the lipopolysaccharide (LPS)-mediated production or secretion of sPLA2 and cPLA2 from A549 cells, a cancer bronchial epithelial cell line, and alveolar macrophages, isolated from bronchoalveolar lavage fluid of ARDS and control patients without cardiopulmonary disease or sepsis. Pre-treatment of cells with azithromycin caused a dose-dependent decrease in the LPS-induced sPLA2-IIA levels in A549 cells. This inhibition was rather due to reduced PLA2G2A mRNA expression and secretion of sPLA2-IIA protein levels, as observed by western blotting and indirect immunofluorescence by confocal microscopy, respectively, than to the inhibition of the enzymic activity per se. On the contrary, azithromycin had no effect on the LPS-induced production or secretion of sPLA2-IIA from alveolar macrophages. The levels of LPS-induced c-PLA2 were not significantly affected by azithromycin in either cell type. We conclude that azithromycin exerts anti-inflammatory properties on lung epithelial cells through the inhibition of both the expression and secretion of LPS-induced sPLA2-IIA, while it does not affect alveolar macrophages.
阿奇霉素是大环内酯类药物的一种，用于治疗感染。这些抗生素还具有独立的抗炎和免疫调节特性。磷脂酶A2同工型参与炎症性肺部疾病的病理生理过程，在炎症反应期间由肺泡巨噬细胞和其他肺细胞产生，可通过破坏肺表面活性物质促进肺损伤。本研究的目的是调查在肺细胞中阿奇霉素是否能分别抑制由炎症触发诱导的分泌型和胞质型磷脂酶A2（sPLA2和cPLA2）。在这方面，我们研究了脂多糖（LPS）介导的sPLA2和cPLA2从A549细胞（一种癌性支气管上皮细胞系）以及从急性呼吸窘迫综合征（ARDS）患者和无心肺疾病或败血症的对照患者的支气管肺泡灌洗液中分离出的肺泡巨噬细胞中的产生或分泌情况。用阿奇霉素预处理细胞导致A549细胞中LPS诱导的sPLA2-IIA水平呈剂量依赖性下降。这种抑制作用更多是由于PLA2G2A mRNA表达降低和sPLA2-IIA蛋白水平分泌减少，分别通过蛋白质印迹法和共聚焦显微镜间接免疫荧光法观察到，而不是对酶活性本身的抑制。相反，阿奇霉素对LPS诱导的肺泡巨噬细胞中sPLA2-IIA的产生或分泌没有影响。在这两种细胞类型中，LPS诱导的c-PLA2水平均未受到阿奇霉素的显著影响。我们得出结论，阿奇霉素通过抑制LPS诱导的sPLA2-IIA的表达和分泌对肺上皮细胞发挥抗炎特性，而对肺泡巨噬细胞没有影响。
