Targeting ALDOA Lactylation Reverses Vascular Remodeling in Pulmonary Hypertension by Disrupting Actin Polymerization and YAP Activation

BACKGROUND: Maladaptive vascular remodeling is a hallmark of pulmonary hypertension (PH), and therapeutic strategies directly targeting the pathological activity of smooth muscle cells remain limited. Metabolic and epigenetic dysregulation are established drivers of PH, and lysine lactylation has emerged as a novel posttranslational modification implicated in diverse diseases; however, its direct contribution to PH progression remains undefined. METHODS: Integrated lactylomic and proteomic profiling was performed in hypoxic human pulmonary arterial smooth muscle cells. The functional role of ALDOA (aldolase A) lactylation at lysine 42 (K42) was assessed using site-specific mutant virus and smooth muscle cell-specific inducible ALDOA knockout mice in 2 established PH models: SU5416+hypoxia in mice and monocrotaline in rats. RESULTS: We identified ALDOA as a prominent lactylation target in hypoxic pulmonary arterial smooth muscle cells, with K42 lactylation consistently elevated in primary pulmonary arterial smooth muscle cells derived from PH rodent models and human PH tissues. Mechanistically, AARS1 (alanyl-tRNA synthetase 1)-mediated ALDOA K42 lactylation enhanced its binding to γ-actin, independent of glycolytic activity. This lactylation-enhanced interaction promoted F-actin polymerization and activated YAP (Yes-associated protein) signaling via LATS1 (large tumor suppressor kinase 1) inhibition, thereby driving pulmonary arterial smooth muscle cell proliferation and phenotypic switching. Moreover, YAP/TEAD4 (TEA domain transcription factor 4)-mediated transcriptional upregulation of AARS1 established a positive feedback loop reinforcing ALDOA K42 lactylation under hypoxia. In vivo, ALDOA inducible knockout or reconstitution with the lactylation-deficient K42R (lysine 42 mutant to arginine) mutant attenuated experimental PH progression, with suppressed F-actin/YAP activation and reduced vascular remodeling. Furthermore, competitive inhibition of lactylation through β‑alanine reduced ALDOA K42 lactylation and ameliorated vascular remodeling in ALDOA-overexpressing rodent PH models. Translationally, pharmacological disruption of the ALDOA/γ-actin interaction by raltegravir suppressed cytoskeletal reorganization and YAP signaling, mitigating PH progression in both mouse and rat models. CONCLUSIONS: AARS1-mediated ALDOA K42 lactylation drives pulmonary vascular remodeling through a mechanism independent of ALDOA's catalytic activity, promoting F-actin polymerization and YAP activation. Precision targeting of this modification selectively inhibits pathological signaling while preserving metabolic homeostasis, highlighting a translational potential for precision intervention in PH.