The role of alveolar epithelial type I cells in bleomycin-induced lung injury: Characterization of fibrosis-relevant signal pathways

I 型肺泡上皮细胞在博来霉素诱导的肺损伤中的作用：纤维化相关信号通路的表征

• 批准号: 373703964
• 负责人: Privatdozentin Dr. Kathrin Barth
• 金额: --
• 依托单位: Institut für Anatomie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/373703964?language=en
• 关键词: role; alveolar; epithelial; type; cells

At the beginning of this project, we studied signaling pathways associated with the purinergic receptor P2X7R in alveolar epithelial type I cells after bleomycin treatment of the human distal lung epithelial cell line, NCI-H441 and of mouse precision-cut lung slice cultures. We confirmed the evidence of the P2X7R-PKC-β-CaMKII axis during earliest stages after bleomycin exposure and we still investigate the importance of this pathway for the maintenance of the alveolar barrier function.Another important aspect of this project relates to the involvement of caveolin-1 in a proper maintaining alveolar barrier function. Here we could demonstrate that caveolin-1 is associated with the Src kinase Fyn. Fyn kinase was found to be selectively expressed in alveolar epithelial type I cells. Bleomycin reduces the transepithelial electrical resistance (TEER) in NCI-H441 cell monolayers and inhibition of Fyn attenuated the loss of TEER under these conditions. In addition, caveolin-1 knockout in mouse lungs presented with an altered cellular distribution of Fyn kinase.It is the main aim during the extension of this project to investigate the effect of pirfenidone, a recently approved anti-fibrosis agent, on anti-fibrotic pathways in alveolar epithelial cells. The planned experiments should clarify, whether p120 catenin, an important binding partner of the E-cadherin-catenin complex, is phosphorylated by Fyn and whether Fyn kinase is a target of pirfenidone. The pirfenidone-induced changes in caveolin-1 and E-cadherin expression, as already demonstrated in this project, emphasize the involvement of Fyn kinase and caveolin-1 in the regulation of intercellular communication in the alveolar epithelium.

在这个项目的开始，我们研究了与嘌呤能受体P2 X7 R在肺泡上皮I型细胞博莱霉素治疗后的人远端肺上皮细胞系，NCI-H441和小鼠精密切割肺切片培养物的信号通路。我们证实了博莱霉素暴露后早期阶段P2 X7 R-PKC-β-CaMKII轴的证据，并且我们仍在研究这一途径对维持肺泡屏障功能的重要性。在这里，我们可以证明小窝蛋白-1与Src激酶Fyn相关。发现Fyn激酶选择性地在肺泡上皮I型细胞中表达。博来霉素降低NCI-H441细胞单层中的跨上皮电阻（TEER），并且Fyn的抑制减弱了在这些条件下TEER的损失。此外，caveolin-1基因敲除后，Fyn激酶的细胞分布发生改变，本项目的主要目的是研究最近批准的抗纤维化药物吡非尼酮（pirfenidone）对肺泡上皮细胞抗纤维化途径的影响。计划的实验应阐明p120连环蛋白（E-钙粘蛋白-连环蛋白复合物的重要结合伴侣）是否被Fyn磷酸化，以及Fyn激酶是否是吡非尼酮的靶点。吡非尼酮诱导的小窝蛋白-1和E-cadherin表达的变化，正如本项目中已经证明的那样，强调了Fyn激酶和小窝蛋白-1参与肺泡上皮细胞间通讯的调节。