Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC V6Z 1Y6, Canada; Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC V5Z 1M9, Canada.
Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC V6Z 1Y6, Canada; Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC V5Z 1M9, Canada.
Matrix Biol. 2024 Sep;132:47-58. doi: 10.1016/j.matbio.2024.06.007. Epub 2024 Jul 4.
Lung fibroblasts play a central role in maintaining lung homeostasis and facilitating repair through the synthesis and organization of the extracellular matrix (ECM). This study investigated the cross-talk between interleukin-1 alpha (IL-1α) and transforming growth factor-β (TGF-β) signaling, two key regulators in tissue repair and fibrosis, in the context of lung fibroblast repair in the healthy lung.
Stimulation of lung fibroblasts with TGF-β1 and TGF-β2 induced collagen-I and fibronectin protein expression (p < 0.05), a response inhibited with co-treatment with IL-1α (p < 0.05). Additionally, TGF-β1 and TGF-β2 induced myofibroblast differentiation, and collagen-I gel contraction, which were both suppressed by IL-1α (p < 0.05). In contrast, interleukin (IL)-6, IL-8 and thymic stromal lymphopoietin induced by IL-1α, were unaffected by TGF-β1 or TGF-β2. Mechanistically, IL-1α administration led to the suppression of TGF-β1 and TGF-β2 signaling, through downregulation of mRNA and protein for TGF-β receptor II and the downstream adaptor protein TRAF6, but not through miR-146a that is known to be induced by IL-1α.
IL-1α acts as a master regulator, modulating TGF-β1 and TGF-β2-induced ECM production, remodeling, and myofibroblast differentiation in human lung fibroblasts, playing a vital role in balancing tissue repair versus fibrosis. Further research is required to understand the dysregulated cross-talk between IL-1α and TGF-β signaling in chronic lung diseases and the exploration of therapeutic opportunities.
Primary human lung fibroblasts (PHLF) were treated with media control, or 1 ng/ml IL-1α with or without 50 ng/ml TGF-β1 or TGF-β2 for 1, 6 and 72 h. Cell lysates were assessed for the expression of ECM proteins and signaling molecules by western blot, miRNA by qPCR, mRNA by RNA sequencing and cell supernatants for cytokine production by ELISA. PHLFs were also seeded in non-tethered collagen-I gels to measure contraction, and myofibroblast differentiation using confocal microscopy.
肺成纤维细胞在维持肺内稳态和促进修复方面发挥着核心作用，其通过细胞外基质（ECM）的合成和组织来实现这一功能。本研究旨在探讨白细胞介素-1α（IL-1α）和转化生长因子-β（TGF-β）信号通路之间的相互作用，这两种信号通路是组织修复和纤维化的关键调节因子，同时也是健康肺组织中成纤维细胞修复的重要调节因子。
TGF-β1 和 TGF-β2 刺激肺成纤维细胞后，可诱导胶原-I 和纤连蛋白蛋白的表达（p < 0.05），而 IL-1α 的共同处理则可抑制这一反应（p < 0.05）。此外，TGF-β1 和 TGF-β2 可诱导肌成纤维细胞分化和胶原-I 凝胶收缩，而 IL-1α 可抑制这两种作用（p < 0.05）。相反，IL-1α 诱导的白细胞介素（IL）-6、IL-8 和胸腺基质淋巴细胞生成素（thymic stromal lymphopoietin）不受 TGF-β1 或 TGF-β2 的影响。从机制上讲，IL-1α 通过下调 TGF-β 受体 II 和下游衔接蛋白 TRAF6 的 mRNA 和蛋白表达，而非通过已知可被 IL-1α 诱导的 miR-146a，抑制 TGF-β1 和 TGF-β2 信号通路。
IL-1α 作为一种主要的调节因子，调节人肺成纤维细胞中 TGF-β1 和 TGF-β2 诱导的 ECM 产生、重塑和肌成纤维细胞分化，在平衡组织修复与纤维化方面发挥着至关重要的作用。需要进一步研究以了解慢性肺部疾病中 IL-1α 和 TGF-β 信号转导的失调，并探索治疗机会。
用含或不含 1ng/mlIL-1α 的培养基或 50ng/mlTGF-β1 或 TGF-β2 处理原代人肺成纤维细胞（PHLF）1、6 和 72 小时。通过 Western blot 检测细胞裂解物中 ECM 蛋白和信号分子的表达、qPCR 检测 miRNA、RNA 测序检测 mRNA，以及通过 ELISA 检测细胞上清液中细胞因子的产生。还将 PHLF 接种于非束缚胶原-I 凝胶中，通过共聚焦显微镜测量收缩和肌成纤维细胞分化。
