Excessive deposition of fibrillar collagen in the interstitial extracellular matrix (ECM) of human lung tissue causes fibrosis, which can ultimately lead to organ failure. Despite our understanding of the molecular mechanisms underlying the disease, no cure for pulmonary fibrosis has yet been found. We screened a drug library and found that dextromethorphan (DXM), a cough expectorant, reduced the amount of excess fibrillar collagen deposited in the ECM in cultured primary human lung fibroblasts, a bleomycin mouse model, and a cultured human precision-cut lung slice model of lung fibrosis. The reduced extracellular fibrillar collagen upon DXM treatment was due to reversible trafficking inhibition of collagen type I (COL1) in the endoplasmic reticulum (ER) in TANGO1- and HSP47-positive structures. Mass spectrometric analysis showed that DXM promoted hyperhydroxylation of proline and lysine residues on various collagens (COL1, COL3, COL4, COL5, COL7, and COL12) and latent transforming growth factor–β–binding protein (LTBP1 and LTBP2) peptides, coinciding with their secretion block. Additionally, proteome profiling of DXM-treated cells showed increased thermal stability of prolyl-hydroxylases P3H2, P3H3, P3H4, P4HA1, and P4HA2, suggesting a change in their activity. Transcriptome analysis of profibrotic stimulated primary human lung fibroblasts and human ex vivo lung slices after DXM treatment showed activation of an antifibrotic program through regulation of multiple pathways, including the MMP-ADAMTS axis, WNT signaling, and fibroblast-to-myofibroblast differentiation. Together, these data obtained from in vitro, in vivo, and ex vivo models of lung fibrogenesis show that DXM has the potential to limit fibrosis through inhibition of COL1 membrane trafficking in the ER.

中文翻译：

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右美沙芬抑制胶原蛋白和胶原样货物分泌，改善肺纤维化


纤维状胶原蛋白在人肺组织的间质细胞外基质 （ECM） 中过度沉积会导致纤维化，最终导致器官衰竭。尽管我们了解了这种疾病背后的分子机制，但尚未找到治愈肺纤维化的方法。我们筛选了一个药物库，发现右美沙芬 （DXM） 是一种止咳祛痰药，可减少培养的原代人肺成纤维细胞、博来霉素小鼠模型和培养的人精确切割肺纤维化模型 ECM 中沉积的过量纤维胶原的数量。DXM 处理后细胞外纤维胶原减少是由于 TANGO1 和 HSP47 阳性结构中内质网 （ER） 中 I 型胶原 （COL1） 的可逆运输抑制。质谱分析显示，DXM 促进各种胶原蛋白 （COL1、COL3、COL4、COL5、COL7 和 COL12） 和潜在转化生长因子-β结合蛋白 （LTBP1 和 LTBP2） 肽上脯氨酸和赖氨酸残基的高羟基化，与它们的分泌阻滞一致。此外，DXM 处理细胞的蛋白质组分析显示脯氨酰羟化酶 P3H2、P3H3、P3H4、P4HA1 和 P4HA2 的热稳定性增加，表明它们的活性发生了变化。DXM 处理后促纤维化刺激的原代人肺成纤维细胞和人离体肺切片的转录组分析显示，通过调节多种途径激活抗纤维化程序，包括 MMP-ADAMTS 轴、WNT 信号传导和成纤维细胞到肌成纤维细胞分化。总之，从肺纤维化的体外、体内和离体模型获得的这些数据表明，DXM 有可能通过抑制 ER 中的 COL1 膜运输来限制纤维化。