A Superoxide Anion-Responsive NIR Fluorogenic Probe Unravels Aucubin’s Dual-Axis Therapeutic Mechanism in Hypoxic Pulmonary Hypertension via Ferroptosis Suppression and Oxidative Injury Mitigation

Hypoxic pulmonary hypertension (HPH) is a class of severe pulmonary vascular diseases characterized by structural remodeling and functional disorders of the pulmonary vasculature induced by chronic hypoxia, which involves Reactive oxygen species (ROS) as a crucial regulatory role. As the primary signaling molecule within the ROS family, the dynamic monitoring of superoxide anion (O 2 · – ) can offer a significant scientific basis for the early diagnosis and timely intervention of HPH. However, specific in vivo detection of HPH-related O 2 · – remains challenging. In this study, we present a near-infrared emissive imaging probe, M534, using a Halogenation-driven molecular engineering strategy that enables highly specific imaging detection of the O 2 · – . M534 not only visualizes the upregulation of the O 2 · – during HPH pathogenesis but also facilitates high-throughput screening and mechanistic investigation of natural antihypertensive agents. In vivo imaging studies revealed that the natural product aucubin (AU), acting through the “Keap1/Nrf2-HO-1-SLC7A11-GPX4” multilevel regulatory axis, integrates multiple mechanisms, including antioxidant enzyme activation and ROS scavenging, to inhibit ferroptosis and superoxide-induced oxidative damage, thereby markedly attenuating hypoxic pulmonary vascular remodeling. Collectively, this work provides a versatile molecular imaging tool for screening HPH preventive and therapeutic agents and further elucidates O 2 · – -related pathological mechanisms in HPH, offering a theoretical basis and potential drug targets for antioxidant therapeutic strategies targeting the Nrf2 pathway.