Advisory Committee Chair
Advisory Committee Members
Date of Award
Degree Name by School
Master of Science (MS) Heersink School of Medicine
Idiopathic pulmonary fibrosis (IPF) is an age-related chronic disease with a me-dian survival period of 3-4 years . Although FDA has approved two drugs that may slow the disease process, there is no effective treatment . IPF is characterized by the excessive deposition of collagen, which leads to deformation of alveolar structure, loss of lung function, and ultimately death . Anti-fibrotic genes such as cyclooxygenase-2 (COX-2) and Heme Oxygenase 1 (HMOX-1) are usually suppressed in the pathogenesis of IPF [4-6], while the mechanisms responsible for the repression of anti-fibrotic genes in IPF are incompletely understood. More evidence has shown that altered epigenetic marks such as histone methylation are involved in silencing anti-fibrosis genes . H3K27Me3 is a key repressive histone mark that mediates gene repression, catalyzed by the methyl-transferase enhancer of Zeste homolog 2 (EZH2) . EZH2 expression is increased in lung fibrosis  and its levels/activity is regulated by the post-translational modifications, such as phosphorylation, acetylation, methylation, ubiquitination, sumoylation, and O-GlcNAcylation . In this study, we investigate the effects of O-GlcNAcylation on anti-fibrotic gene expression via the EZH2-H3K27Me3 axis. Our results indicate that O-Glc-NAc levels are increased in IPF lung tissue compared to control human lungs by IHC IV staining and western blots. In primary human lung fibroblasts, inhibition of OGT (O-Glc-NAc transferase) with the OGT inhibitor, OSMI-1, reduced O-GlcNAc levels and EZH2 protein expression as determined by Western blot analysis. In addition, we noticed the significantly increased expression of anti-fibrotic genes, COX-2 and HMOX-1, at the mRNA level in lung fibroblasts with OGT inhibition. Our ChIP assay confirmed that COX-2 and HMOX1 are regulated by H3K27Me3. This indicates that O-GlcNAc can regulate anti-fibrotic genes in lung fibrosis through EZH2-H3K27Me3 axis. Our results support a central role of O-GlcNAc for EZH2-mediated histone hypermethylation in anti-fibrotic genes epigenetic silencing in IPF.
Wu, Qiuming, "Epigenetic Regulation by O-GlcNAc Alters Anti-Fibrotic Gene Expression in IPF Fibroblasts" (2022). All ETDs from UAB. 510.