Pulmonary Department, Meir Medical Center, Kfar Saba 4428164, Israel.
Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
Int J Mol Sci. 2021 Mar 24;22(7):3331. doi: 10.3390/ijms22073331.
Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with poor prognosis. The IPF-conditioned matrix (IPF-CM) system enables the study of matrix-fibroblast interplay. While effective at slowing fibrosis, nintedanib has limitations and the mechanism is not fully elucidated. In the current work, we explored the underlying signaling pathways and characterized nintedanib involvement in the IPF-CM fibrotic process. Results were validated using IPF patient samples and bleomycin-treated animals with/without oral and inhaled nintedanib. IPF-derived primary human lung fibroblasts (HLFs) were cultured on Matrigel and then cleared using NHOH, creating the IPF-CM. Normal HLF-CM served as control. RNA-sequencing, PCR and western-blots were performed. HIF1α targets were evaluated by immunohistochemistry in bleomycin-treated rats with/without nintedanib and in patient samples with IPF. HLFs cultured on IPF-CM showed over-expression of 'HIF1α signaling pathway' (KEGG, < 0.0001), with emphasis on (PAI-1), and . IPF patient samples showed high HIF1α staining, especially in established fibrous tissue. PAI-1 was overexpressed, mainly in alveolar macrophages. Nintedanib completely reduced HIF1α upregulation in the IPF-CM and rat-bleomycin models. IPF-HLFs alter the extracellular matrix, thus creating a matrix that further propagates an IPF-like phenotype in normal HLFs. This pro-fibrotic loop includes the HIF1α pathway, which can be blocked by nintedanib.
特发性肺纤维化（IPF）是一种预后不良的进行性肺部疾病。IPF 条件基质（IPF-CM）系统可用于研究基质-成纤维细胞相互作用。尼达尼布虽然能有效减缓纤维化，但存在局限性，其机制尚未完全阐明。在本研究中，我们探索了潜在的信号通路，并研究了尼达尼布在 IPF-CM 纤维化过程中的作用。使用 IPF 患者样本和博来霉素处理的动物（口服和吸入尼达尼布）验证了结果。从 IPF 患者中分离出的原代人肺成纤维细胞（HLFs）在 Matrigel 上培养，然后用 NHOH 清除，从而构建 IPF-CM。正常 HLF-CM 作为对照。进行了 RNA 测序、PCR 和 Western blot 分析。通过免疫组化评估了缺氧诱导因子 1α（HIF1α）在博来霉素处理的大鼠（有无尼达尼布）和 IPF 患者样本中的靶标。在 IPF-CM 上培养的 HLFs 显示“HIF1α 信号通路”（KEGG，<0.0001）过度表达，重点是 （PAI-1） 和 。IPF 患者样本中 HIF1α 染色高，尤其是在已形成的纤维组织中。PAI-1 过度表达，主要在肺泡巨噬细胞中。尼达尼布完全抑制了 IPF-CM 和大鼠博来霉素模型中 HIF1α 的上调。IPF-HLFs 改变细胞外基质，从而在正常 HLFs 中产生类似于 IPF 的表型。这个促纤维化循环包括 HIF1α 途径，该途径可被尼达尼布阻断。
