Role of neuregulin-1β in dexamethasone-enhanced surfactant phospholipid synthesis in rat fetal type ii pneumocytes

Surfactant production is known to involve a cellular communication between lung fibroblasts and the type II pneumocytes. Glucocorticoids induce the production of a peptide by lung fibroblasts, fibroblast-pneumocyte factor (FPF), which sequentially acts on type II cells to enhance the synthesis of surfactant phospholipid. Our findings show that fibroblast-conditioned medium (FCM), generated in the presence of dexamethasone, not only enhanced surfactant phospholipid synthesis in type II cells but also contained an elevated concentration of neuregulin-1β (NRG1β). Even though it has been earlier proposed that leptin has many of the characteristics of FPF, recent research has revealed that NRG1β also has many similar attributes. In the current study, exposure of the type II cells to a commercially available form of NRG1β (heregulin-1β) directly stimulated by more than three-fold the rate of phospholipid synthesis (p