Nuclear respiratory factor-1 negatively regulates TGF-β1 and attenuates pulmonary fibrosis
Hagir B. Suliman,
Zachary Healy,
Fabio Zobi,
Bryan D. Kraft,
Karen Welty-Wolf,
Joshua Smith,
Christina Barkauskas,
Claude A. Piantadosi
Affiliations
Hagir B. Suliman
Department of Medicine, Duke University School of Medicine, 200 Trent Drive, Durham, NC 27710, USA; Department of Anaesthesiology, Duke University School of Medicine, Durham, NC, USA; Department of Pathology, Duke University School of Medicine, Durham, NC, USA; Corresponding author
Zachary Healy
Department of Medicine, Duke University School of Medicine, 200 Trent Drive, Durham, NC 27710, USA
Fabio Zobi
Department of Chemistry, University of Fribourg, Fribourg, Switzerland
Bryan D. Kraft
Department of Medicine, Duke University School of Medicine, 200 Trent Drive, Durham, NC 27710, USA
Karen Welty-Wolf
Department of Medicine, Duke University School of Medicine, 200 Trent Drive, Durham, NC 27710, USA
Joshua Smith
Department of Medicine, Duke University School of Medicine, 200 Trent Drive, Durham, NC 27710, USA
Christina Barkauskas
Department of Medicine, Duke University School of Medicine, 200 Trent Drive, Durham, NC 27710, USA
Claude A. Piantadosi
Department of Medicine, Duke University School of Medicine, 200 Trent Drive, Durham, NC 27710, USA; Department of Anaesthesiology, Duke University School of Medicine, Durham, NC, USA; Department of Pathology, Duke University School of Medicine, Durham, NC, USA
Summary: The preclinical model of bleomycin-induced lung fibrosis is useful to study mechanisms related to human pulmonary fibrosis. Using BLM in mice, we find low HO-1 expression. Although a unique Rhenium-CO-releasing molecule (ReCORM) up-regulates HO-1, NRF-1, CCN5, and SMAD7, it reduces TGFβ1, TGFβr1, collagen, α-SMA, and phosphorylated Smad2/3 levels in mouse lung and in human lung fibroblasts. ChIP assay studies confirm NRF-1 binding to the promoters of TGFβ1 repressors CCN5 and Smad7. ReCORM did not blunt lung fibrosis in Hmox1-deficient alveolar type 2 cell knockout mice, suggesting this gene participates in lung protection. In human lung fibroblasts, TGFβ1-dependent production of α-SMA is abolished by ReCORM or by NRF-1 gene transfection. We demonstrate effective HO-1/NRF-1 signaling in lung AT2 cells protects against BLM induced lung injury and fibrosis by maintaining mitochondrial health, function, and suppressing the TGFβ1 pathway. Thus, protection of AT2 cell mitochondrial integrity via HO-1/NRF-1 presents an innovative therapeutic target.
