Metabolite-driven epigenetic modifications remodel immune cell functions in COPD: From Lactylation to Succinylation

Chronic obstructive pulmonary disease (COPD) is characterized by persistent airway inflammation, progressive immune dysfunction, and irreversible structural remodeling. Although cigarette smoke-induced oxidative stress has long been recognized as the predominant pathogenic driver, conventional inflammatory theories fail to fully account for the sustained inflammatory state that persists even after smoking cessation. Accumulating evidence indicates that COPD is governed by a metabolite-centered epigenetic regulatory network. Intracellular metabolic intermediates function not only as substrates for energy metabolism, but also as signaling molecules that directly modulate chromatin architecture and transcriptional programs. In this context, metabolic reprogramming emerges as a pivotal determinant of immune cell fate and inflammatory memory formation. This review systematically summarizes recent research advances in the "metabolite-redox-epigenetics" axis in COPD. We specifically discuss histone lactylation as a glycolysis-dependent inflammatory amplification mechanism and propose that histone succinylation represents a redox-sensitive epigenetic mechanism linked to mitochondrial dysfunction, bridging tricarboxylic acid (TCA) cycle dysregulation and persistent immune activation. We further integrate acetylation, crotonylation, β-hydroxybutyrylation, DNA methylation, and RNA m6A modification to construct a unified immunometabolic regulatory network. We propose that COPD is essentially a metabolically imprinted inflammatory memory disease, whose core mechanism resides in the chronic oxidative stress-triggered persistent remodeling of chromatin accessibility, which stably enforces pathogenic immune phenotypes. Targeting metabolite-driven epigenetic remodeling may offer novel therapeutic strategies to reverse chronic inflammatory memory and restore immune homeostasis. Recent evidence further suggests that cGAS-STING-mediated mitochondrial DNA sensing, inflammasome-dependent pyroptosis, gut-lung axis-derived metabolites, and AMPK/SIRT1/PGC-1α signaling may provide additional links between metabolic stress, epithelial injury, and immune dysfunction.