Abstract
This study aimed to examine the influence of the Neuregulin-1 (NRG1)/ERBB4 signaling pathway on the function of human pulmonary artery endothelial cells (HPAECs) and investigate the underlying mechanisms. Enzyme-linked immunosorbent assay indicated that ERBB4 levels in the serum of patients with pulmonary embolism (PE) were significantly higher than those of healthy controls (p < 0.05). In cellular studies, thrombin stimulation for 6 h led to a significant decrease in cell viability and overexpression of ERBB4 compared to control (p < 0.05). In the NRG1 group, apoptosis of HPAECs was reduced (p < 0.05), accompanied by a decrease in ERBB4 expression and an increase in p-ERBB4, phosphorylated serine/threonine kinase proteins (Akt) (p-Akt), and p-phosphoinositide 3-kinase (PI3K) expression (p < 0.05). In the AG1478 group, there was a significant increase in HPAEC apoptosis and a significant decrease in p-ERBB4 and ERBB4 expression compared to the Con group (p < 0.05). In the AG1478 + NRG1 group, there was an increase in the apoptosis rate and a significant decrease in the expression of p-ERBB4, ERBB4, p-Akt, and phosphorylated PI3K compared to the NRG1 group (p < 0.05). In animal studies, the PE group showed an increase in the expression of ERBB4 and p-ERBB4 compared to the Con group (p < 0.05). NRG1 treatment led to a significant reduction in embolism severity with decreased ERBB4 expression and increased p-ERBB4 expression (p < 0.05). Gene set enrichment analysis identified five pathways that were significantly associated with high ERBB4 expression, including CHOLESTEROL HOMEOSTASIS, OXIDATIVE PHOSPHORYLATION, and FATTY ACID METABOLISM (p < 0.05). Therefore, NRG1 inhibits apoptosis of HPAECs, accompanied by a decrease in ERBB4 and an increase in p-ERBB4. NRG1 inhibition in HPAECs apoptosis can be partially reversed by inhibiting ERBB4 expression with AG1478. ERBB4 has the potential to be a novel biological marker of PE.