3-Bromopyruvate ameliorates pulmonary arterial hypertension by improving mitochondrial metabolism

Aims: Abnormal mitochondrial metabolism is an essential factor for excessive proliferation of pulmonary artery smooth muscle cells (PASMCs), which drives the pathological process of pulmonary arterial hypertension (PAH). 3-Bromopyruvate (3-BrPA) is an effective glycolytic inhibitor that improves mitochondrial metabolism, thereby repressing anomalous cell proliferation. Main methods: An experimental PAH model was established by injection of monocrotaline (MCT) in male Sprague Dawley rats, following which rats were assigned to three groups: control, MCT, and 3-BrPA groups. Three days post injection of MCT, rats were treated with 3-BrPA or vehicle for 4 weeks. At the end of the study, hemodynamic data were measured to confirm PAH condition. Indicators of pulmonary arterial and right ventricular (RV) remodeling as well as the proliferative ability of PASMCs were assayed. Additionally, mitochondrial morphology and function, and antiglycolytic and antiproliferative pathways and genes were analyzed. Key findings: Treatment with 3-BrPA effectively improved pulmonary vascular remodeling and right ventricular function, inhibited PASMC proliferation, and preserved mitochondrial morphology and function. Besides, 3-BrPA treatment inhibited the PI3K/AKT/mTOR pathway and regulated the expression of antiproliferative genes in PASMCs. However, bloody ascites, bloating, and cirrhosis of organs were observed in some 3-BrPA treated rats. Significance: 3-BrPA acts as an important glycolytic inhibitor to improve energy metabolism and reverse the course of PAH. However, 3-BrPA is associated with side effects in MCT-induced rats, indicating that it should be caution in drug delivery dosage, and further studies are needed to evaluate this toxicological mechanism.