Multi-omics and experimental validation reveal the proliferative mechanism of ACSL4 in pulmonary hypertension and identify potential FDA-approved drugs via in silico screening.
BACKGROUND Pulmonary hypertension (PH) is a life-threatening blood vessel disorder marked by remodeling of the pulmonary arteries. A key feature of this process is the uncontrolled growth of pulmonary artery smooth muscle cells (PASMCs). Although changes in fatty acid metabolism are thought to drive this abnormal cell growth, the exact molecular mechanisms behind it are still not fully understood. OBJECTIVE This study aimed to identify key regulators of fatty acid metabolism in PH using multi-omics data and lab experiments, and to explore how they contribute to PASMC overgrowth, with the goal of uncovering new treatment targets. METHODS We analyzed PH-related transcriptome data (GSE113439) and protein interaction networks to pinpoint central fatty acid metabolism genes. Functional enrichment, immune cell infiltration, and single-cell RNA sequencing (GSE210248) were used to explore the role of a key gene, ACSL4. We then screened FDA-approved drugs for potential ACSL4 inhibitors using molecular docking and dynamics simulations. Finally, in a rat model of PH induced by chronic low oxygen and in primary PASMCs, we tested how blocking ACSL4 (with the inhibitor PRGL493 or siRNA) affected cell growth and the pathways involved. RESULTS ACSL4 stood out as a central player in fatty acid metabolism in PH. Its high expression was linked to changes in the immune environment and early disease stages. Functional analysis showed that ACSL4 and its related networks are involved in lipid metabolism, PPAR signaling, and ferroptosis. Virtual screening and molecular dynamics pointed to three FDA-approved drugs that bind tightly and steadily to ACSL4. In lab and animal studies, ACSL4 levels went up in lung tissue and PASMCs exposed to low oxygen, along with shifts in fatty acid profiles and increased PASMC growth. Blocking or silencing ACSL4 eased this overgrowth by helping restore normal VGLL4/YAP levels and reversing the suppression of the Hippo pathway. CONCLUSION This study uncovers a novel mechanism by which ACSL4 fuels PASMC growth in PH through reshaping fatty acid metabolism and targeting the VGLL4/YAP signaling axis. Although the role of ACSL4 in pulmonary hypertension has been previously reported, its function via the VGLL4/YAP axis is a novel finding. These findings highlight a key pathway in PH progression and point to ACSL4 as a possible target for new treatments.