Abstract：
BACKGROUND: 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.
RESULTS: 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.
CONCLUSIONS: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.
METHODS: 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.
摘要：
背景：肺成纤维细胞在维持肺稳态和通过细胞外基质（ECM）的合成和组织促进修复中起着核心作用。这项研究调查了白细胞介素-1α（IL-1α）和转化生长因子-β（TGF-β）信号之间的串扰，组织修复和纤维化的两个关键调节剂，在健康肺的肺成纤维细胞修复的背景下。
结果：用TGF-β1和TGF-β2刺激肺成纤维细胞诱导I型胶原和纤连蛋白表达（p<0.05），与IL-1α共同治疗抑制了反应(p<0.05)。此外,TGF-β1和TGF-β2诱导肌成纤维细胞分化,胶原蛋白-I凝胶收缩，均被IL-1α抑制(p<0.05)。相比之下,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，不受TGF-β1或TGF-β2的影响。机械上,IL-1α给药导致TGF-β1和TGF-β2信号的抑制，通过下调TGF-β受体II和下游衔接蛋白TRAF6的mRNA和蛋白质，但不通过已知由IL-1α诱导的miR-146a。
结论：IL-1α作为主调节因子，调节TGF-β1和TGF-β2诱导的ECM产生，重塑，和人肺成纤维细胞的肌成纤维细胞分化，在平衡组织修复和纤维化中起着至关重要的作用。需要进一步的研究来了解慢性肺部疾病中IL-1α和TGF-β信号传导之间失调的串扰以及探索治疗机会。
方法：用培养基对照处理原代人肺成纤维细胞（PHLF），或1ng/mlIL-1α，含或不含50ng/mlTGF-β1或TGF-β2，持续1、6和72小时。通过蛋白质印迹评估细胞裂解物的ECM蛋白和信号分子的表达，miRNA通过qPCR,通过RNA测序的mRNA和通过ELISA用于细胞因子产生的细胞上清液。还将PHLF接种在非束缚的胶原蛋白I凝胶中以测量收缩，和肌成纤维细胞分化使用共聚焦显微镜。
结果：用TGF-β1和TGF-β2刺激肺成纤维细胞诱导I型胶原和纤连蛋白表达（p<0.05），与IL-1α共同治疗抑制了反应(p<0.05)。此外,TGF-β1和TGF-β2诱导肌成纤维细胞分化,胶原蛋白-I凝胶收缩，均被IL-1α抑制(p<0.05)。相比之下,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，不受TGF-β1或TGF-β2的影响。机械上,IL-1α给药导致TGF-β1和TGF-β2信号的抑制，通过下调TGF-β受体II和下游衔接蛋白TRAF6的mRNA和蛋白质，但不通过已知由IL-1α诱导的miR-146a。
结论：IL-1α作为主调节因子，调节TGF-β1和TGF-β2诱导的ECM产生，重塑，和人肺成纤维细胞的肌成纤维细胞分化，在平衡组织修复和纤维化中起着至关重要的作用。需要进一步的研究来了解慢性肺部疾病中IL-1α和TGF-β信号传导之间失调的串扰以及探索治疗机会。
方法：用培养基对照处理原代人肺成纤维细胞（PHLF），或1ng/mlIL-1α，含或不含50ng/mlTGF-β1或TGF-β2，持续1、6和72小时。通过蛋白质印迹评估细胞裂解物的ECM蛋白和信号分子的表达，miRNA通过qPCR,通过RNA测序的mRNA和通过ELISA用于细胞因子产生的细胞上清液。还将PHLF接种在非束缚的胶原蛋白I凝胶中以测量收缩，和肌成纤维细胞分化使用共聚焦显微镜。
