DOT1L Drives Endothelial-to-Mesenchymal Transition and Fibrotic Vascular Remodeling via H3K79 Methylation.
Summary
This mechanistic study identifies DOT1L-mediated H3K79 methylation as a central epigenetic driver of EndoMT and pulmonary fibrosis. TGFβ-SMAD2 upregulates DOT1L, increasing H3K79me2 at fibrosis genes; endothelial Dot1L deletion attenuates bleomycin-induced fibrosis in mice.
Key Findings
- TGFβ stimulation increases DOT1L and H3K79me2 during EndoMT in endothelial cells.
- SMAD2 directly binds the DOT1L promoter, promoting H3K79me2 deposition at fibrosis gene loci.
- Endothelial-specific Dot1L deletion reduces fibrotic remodeling and collagen deposition in bleomycin-induced pulmonary fibrosis.
Clinical Implications
While preclinical, DOT1L inhibition could emerge as a novel antifibrotic strategy in idiopathic pulmonary fibrosis and related conditions, informing biomarker-guided trials targeting EndoMT.
Why It Matters
It reveals a druggable epigenetic axis linking TGFβ signaling to transcriptional activation of fibrotic programs via H3K79me2, providing a concrete target (DOT1L) for antifibrotic therapy.
Limitations
- Sample sizes and detailed quantitative effect sizes are not reported in the abstract
- Translatability to human disease and on-target safety of DOT1L inhibition remain to be established
Future Directions
Develop selective DOT1L inhibitors; define EndoMT biomarkers of target engagement; test combination strategies with TGFβ/SMAD modulators in preclinical fibrosis models and early-phase trials.
Study Information
- Study Type
- Basic/mechanistic study
- Research Domain
- Pathophysiology
- Evidence Level
- V - Preclinical mechanistic evidence from in vitro and animal models
- Study Design
- OTHER