Platelet-Derived TGF (Transforming Growth Factor)-β1 Enhances the Aerobic Glycolysis of Pulmonary Arterial Smooth Muscle Cells by PKM2 (Pyruvate Kinase Muscle Isoform 2) Upregulation.

Abstract

Metabolic reprogramming is a hallmark of pulmonary arterial hypertension. Platelet activation has been implicated in pulmonary arterial hypertension (PAH), whereas the role of platelet in the pathogenesis of PAH remains unclear. First, we explored the platelet function of semaxanib' a inhibitor of VEGF receptor (SU5416)/hypoxia mice and monocrotaline-injected rats PAH model. Then we investigated pulmonary arterial smooth muscle cell aerobic glycolysis after being treated with platelet supernatant. TGF (transforming growth factor)-βRI, pyruvate kinase muscle 2, and other antagonists were applied to identify the underlying mechanism. In addition, platelet-specific deletion TGF-β1 mice were exposed to chronic hypoxia and SU5416. Cardiopulmonary hemodynamics, vascular remodeling, and aerobic glycolysis of pulmonary arterial smooth muscle cell were determined. Here, we demonstrate that platelet-released TGF-β1 enhances the aerobic glycolysis of pulmonary arterial smooth muscle cells after platelet activation via increasing pyruvate kinase muscle 2 expression. Mechanistically, platelet-derived TGF-β1 regulate spyruvate kinase muscle 2 expression through mTOR (mammalian target of rapamycin)/c-Myc/PTBP-1(polypyrimidine tract binding protein 1)/hnRNPA-1(heterogeneous nuclear ribonucleoprotein A1) pathway. Platelet TGF-β1 deficiency mice are significantly protected from SU5416 plus chronic hypoxia-induced PAH, including attenuated increases in right ventricular systolic pressure and less pulmonary vascular remodeling. Also, in Pf4cre+ Tgfb1fl/fl mice, pulmonary arterial smooth muscle cells showed lower glycolysis capacity and their pyruvate kinase muscle 2 expression decreased. Our data demonstrate that TGF-β1 released by platelet contributes to the pathogenesis of PAH and further highlights the role of platelet in PAH.