Department of Molecular Pharmacology, Groningen Research Institute for Asthma and COPD, University of Groningen , Groningen , The Netherlands.
Lung Repair and Regeneration Unit, Helmholtz-Zentrum München, Ludwig-Maximilians-University, University Hospital Grosshadern, Member of the German Center of Lung Research , Munich , Germany.
Am J Physiol Lung Cell Mol Physiol. 2019 Jul 1;317(1):L14-L28. doi: 10.1152/ajplung.00400.2018. Epub 2019 Apr 10.
Transforming growth factor-β (TGF-β)-induced fibroblast-to-myofibroblast differentiation contributes to remodeling in chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis, but whether this impacts the ability of fibroblasts to support lung epithelial repair remains little explored. We pretreated human lung fibroblasts [primary (phFB) or MRC5 cells] with recombinant human TGF-β to induce myofibroblast differentiation, then cocultured them with adult mouse lung epithelial cell adhesion molecule-positive cells (EpCAM) to investigate their capacity to support epithelial organoid formation in vitro. While control phFB and MRC5 lung fibroblasts supported organoid formation of mouse EpCAM cells, TGF-β pretreatment of both phFB and MRC5 impaired organoid-supporting ability. We performed RNA sequencing of TGF-β-treated phFB, which revealed altered expression of key Wnt signaling pathway components and Wnt/β-catenin target genes, and modulated expression of secreted factors involved in mesenchymal-epithelial signaling. TGF-β profoundly skewed the transcriptional program induced by the Wnt/β-catenin activator CHIR99021. Supplementing organoid culture media recombinant hepatocyte growth factor or fibroblast growth factor 7 promoted organoid formation when using TGF-β pretreated fibroblasts. In conclusion, TGF-β-induced myofibroblast differentiation results in Wnt/β-catenin pathway skewing and impairs fibroblast ability to support epithelial repair likely through multiple mechanisms, including modulation of secreted growth factors.
转化生长因子-β（TGF-β）诱导的成纤维细胞向肌成纤维细胞分化有助于慢性阻塞性肺疾病和特发性肺纤维化的重塑，但这种分化是否会影响成纤维细胞支持肺上皮修复的能力仍知之甚少。我们用重组人 TGF-β预处理人肺成纤维细胞（原代 [phFB] 或 MRC5 细胞）以诱导肌成纤维细胞分化，然后将其与成年小鼠肺上皮细胞黏附分子阳性细胞（EpCAM）共培养，以研究它们在体外支持上皮类器官形成的能力。虽然对照 phFB 和 MRC5 肺成纤维细胞支持小鼠 EpCAM 细胞的类器官形成，但 phFB 和 MRC5 的 TGF-β预处理均损害了类器官支持能力。我们对 TGF-β处理的 phFB 进行了 RNA 测序，结果显示关键 Wnt 信号通路成分和 Wnt/β-catenin 靶基因的表达发生改变，并调节了参与间质-上皮信号的分泌因子的表达。TGF-β 严重改变了 Wnt/β-catenin 激活剂 CHIR99021 诱导的转录程序。在使用 TGF-β预处理的成纤维细胞时，在类器官培养物中补充重组肝细胞生长因子或成纤维细胞生长因子 7 可促进类器官形成。总之，TGF-β诱导的肌成纤维细胞分化导致 Wnt/β-catenin 途径的倾斜，并通过多种机制损害成纤维细胞支持上皮修复的能力，包括调节分泌生长因子。
