Endothelial H2S-AMPK dysfunction upregulates the angiocrine factor PAI-1 and contributes to lung fibrosis

Dysfunction of the vascular angiocrine system is critically involved in regenerative defects and fibrosis of injured organs. Previous studies have identified various angiocrine factors and found that risk factors such as aging and metabolic disorders can disturb the vascular angiocrine system in fibrotic organs. One existing key gap is what sense the fibrotic risk to modulate the vascular angiocrine system in organ fibrosis. Here, using human and mouse data, we discovered that the metabolic pathway hydrogen sulfide (H2S)-AMP-activated protein kinase (AMPK) is a sensor of fibrotic stress and serves as a key mechanism upregulating the angiocrine factor plasminogen activator inhibitor-1 (PAI-1) in endothelial cells to participate in lung fibrosis. Overall design: In order to investigate the specific mechanisms underlying the regulation of pulmonary fibrosis by AMPK in vascular endothelial cells, we utilized lentiviral-mediated short hairpin RNA (shRNA) to knockdown PRKAA1 in human umbilical vein endothelial cells (HUVECs). Subsequently, HUVECs were stimulated with TGFß for 24 hours and samples were collected for bulk RNA sequencing (n=3).