OSA Initiates Histone Lactylation That Drives PDE4B/FUS/AGT Axis to Pulmonary Hypertension.

Obstructive sleep apnea (OSA) is strongly associated with an increased risk of hypertension; however, the molecular mechanisms linking these two conditions remain incompletely understood. In this study, we identified phosphodiesterase 4B (PDE4B) as a key mediator in the development of OSA-related hypertension. Using integrated bioinformatics analysis and experimental validation, we found that PDE4B expression was significantly elevated in both cell and animal models of OSA combined with pulmonary hypertension. Functional studies demonstrated that PDE4B promotes pulmonary artery smooth muscle cell (PASMC) proliferation and migration, contributing to vascular remodelling. Mechanistically, we uncovered that lactate accumulation under hypoxic conditions induces histone lactylation at the PDE4B promoter, enhancing its transcriptional activity. Furthermore, PDE4B was shown to regulate the phosphorylation and nuclear translocation of FUS, which binds to the angiotensinogen (AGT) promoter and enhances AGT expression, thereby promoting pulmonary hypertension. These findings reveal a novel PDE4B-FUS-AGT signalling axis driven by epigenetic modifications in OSA-induced hypertension, offering potential therapeutic targets for patients with this comorbidity.