Related Experiment Video
Updated: Dec 15, 2025
Refined Murine Model of Idiopathic Pulmonary Fibrosis
Published on: June 17, 2025
CMH-Small Molecule Docks into SIRT1, Elicits Human IPF-Lung Fibroblast Cell Death, Inhibits Ku70-deacetylation, FLIP
Jenya Konikov-Rozenman1, Raphael Breuer1,2, Naftali Kaminski3
1Lung Cellular and Molecular Biology Laboratory, Institute of Pulmonary Medicine, Hadassah-Hebrew University Medical Center, POB 12000, Jerusalem 91120, Israel.
Abstract:
Regenerative capacity in vital organs is limited by fibrosis propensity. Idiopathic pulmonary fibrosis (IPF), a progressive lung disease linked with aging, is a classic example. In this study, we show that in flow cytometry, immunoblots (IB) and in lung sections, FLIP levels can be regulated, in vivo and in vitro, through SIRT1 activity inhibition by CMH (4-(4-Chloro-2-methylphenoxy)-N-hydroxybutanamide), a small molecule that, as we determined here by structural biology calculations, docked into its nonhistone substrate Ku70-binding site. Ku70 immunoprecipitations and immunoblots confirmed our theory that Ku70-deacetylation, Ku70/FLIP complex, myofibroblast resistance to apoptosis, cell survival, and lung fibrosis in bleomycin-treated mice, are reduced and regulated by CMH. Thus, small molecules associated with SIRT1-mediated regulation of Ku70 deacetylation, affecting FLIP stabilization in fibrotic-lung myofibroblasts, may be a useful strategy, enabling tissue regeneration.
Insights
CMH, a small molecule, inhibits SIRT1 activity to reduce FLIP stabilization in lung myofibroblasts. This finding offers a potential strategy for enhancing tissue regeneration by targeting fibrosis in diseases like idiopathic pulmonary fibrosis (IPF).
Area of Science:
- Molecular Biology
- Regenerative Medicine
- Pulmonary Fibrosis Research
Background:
- Fibrosis limits organ regeneration, with idiopathic pulmonary fibrosis (IPF) being a key example.
- Understanding molecular mechanisms regulating fibrosis is crucial for developing regenerative therapies.
Purpose of the Study:
- To investigate the role of SIRT1 activity and its regulation in lung fibrosis.
- To explore the therapeutic potential of small molecules targeting fibrosis pathways.
Main Methods:
- Utilized flow cytometry, immunoblots (IB), and lung sections for analysis.
- Employed structural biology calculations to determine small molecule binding.
- Conducted in vivo studies using bleomycin-treated mice.
Main Results:
- CMH, a small molecule, inhibits SIRT1 activity, reducing FLIP stabilization in myofibroblasts.
- CMH treatment decreased Ku70-deacetylation, Ku70/FLIP complex formation, and myofibroblast resistance to apoptosis.
- CMH treatment reduced lung fibrosis in a mouse model.
Conclusions:
- SIRT1-mediated regulation of Ku70 deacetylation impacts FLIP stabilization in fibrotic lung myofibroblasts.
- Targeting SIRT1 with small molecules like CMH may offer a novel strategy for treating fibrotic diseases and promoting tissue regeneration.
