ZEB1-Driven GLS1 Transcription Promotes Macrophage Glutamine Metabolism in PAH

BACKGROUND: The transcriptional mechanisms governing macrophage glutamine metabolism in pulmonary arterial hypertension remain incompletely understood. We investigated the role of ZEB1 (zinc finger E-box-binding homeobox 1)-mediated transcriptional regulation in macrophage metabolic reprogramming and the development of pulmonary arterial hypertension. METHODS: Clinical samples and multiomics data sets were analyzed to characterize ZEB1 expression in pulmonary arterial hypertension. Myeloid-specific ZEB1 conditional knockout mice were subjected to hypoxia-induced pulmonary hypertension. Transcriptomic sequencing, metabolomic profiling, chromatin immunoprecipitation-quantitative polymerase chain reaction, dual-luciferase reporter assays, and coimmunoprecipitation were integrated to define ZEB1-dependent molecular, metabolic, and inflammatory programs in pulmonary and bone marrow-derived macrophages. Therapeutic potential was further evaluated using pharmacological interventions and adenoviral ZEB1 silencing in monocrotaline-induced pulmonary hypertension in rats. RESULTS: ZEB1 was upregulated in pulmonary arterial hypertension and enriched in recruited disease-associated macrophages. Myeloid-specific ZEB1 deletion attenuated macrophage inflammation, pulmonary vascular remodeling, and right ventricular dysfunction. Mechanistically, ZEB1 bound the GLS (glutaminase) promoter and recruited BRD4 (bromodomain-containing protein 4), enhancing histone H3 lysine 27 acetylation at the GLS promoter and promoting GLS transcription and glutamine metabolic reprogramming. Restoration of GLS partially reversed the metabolic and inflammatory effects of ZEB1 deficiency. Pharmacological targeting of ZEB1, combined BRD4 and GLS inhibition, and adenoviral ZEB1 silencing ameliorated experimental pulmonary hypertension. CONCLUSIONS: ZEB1 promotes macrophage glutamine metabolic reprogramming by recruiting BRD4 and enhancing histone H3 lysine 27 acetylation-dependent GLS transcription. This ZEB1-driven metabolic program promotes macrophage inflammation and pulmonary vascular remodeling, identifying the ZEB1-BRD4-GLS regulatory axis as a potential therapeutic target in pulmonary arterial hypertension.