Endothelial H2S-AMPK dysfunction upregulates the angiocrine factor PAI-1 and contributes to lung fibrosis. 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 TGFβ for 24 hours and samples were collected for bulk RNA sequencing (n=3).

血管旁分泌（vascular angiocrine）系统功能异常，与受损器官的再生缺陷及纤维化进程密切相关。既往研究已鉴定出多种血管旁分泌因子，并发现衰老、代谢紊乱等危险因素可扰乱纤维化器官中的血管旁分泌系统。当前尚存的关键研究空白在于：纤维化相关风险因素究竟以何种机制调控器官纤维化进程中的血管旁分泌系统。本研究利用人类与小鼠样本数据，揭示了硫化氢（hydrogen sulfide, H2S）-腺苷酸活化蛋白激酶（AMP-activated protein kinase, AMPK）代谢通路可作为纤维化应激的感受器，并作为核心机制上调内皮细胞中的血管旁分泌因子纤溶酶原激活物抑制剂-1（plasminogen activator inhibitor-1, PAI-1），进而参与肺纤维化的发生发展。实验设计：为探究血管内皮细胞中腺苷酸活化蛋白激酶（AMPK）调控肺纤维化的具体分子机制，本研究采用慢病毒介导的短发夹RNA（shRNA）敲低人脐静脉内皮细胞（HUVECs）中的PRKAA1基因。随后用转化生长因子β（TGFβ）刺激HUVECs 24小时，收集样本进行批量RNA测序（n=3）。