Co-culture with bronchial epithelial cells and hypoxia promote ADAM33 expression to regulate activation, ferroptosis, proliferation, migration, and apoptosis of embryonic lung fibroblasts

Abstract

Asthma is a common chronic respiratory system disease, and thoroughly revealing its pathological mechanism is still a major challenge in the current biomedical field. Studies on embryonic lung fibroblasts have found that hypoxia promoted the expression and secretion of ADAM33 in a time-dependent manner. Co-culture with bronchial epithelial cells (co-BECs) also induced the expression of ADAM33, and hypoxia further enhanced the effect of co-culture on promoting ADAM33 expression. Western blot and/or immunofluorescence detection showed that co-BECs significantly enhanced the expression of α-SMA, vimentin, calponin, collagen I and vinculin, but the effect on promoting desmin expression was not significant; ADAM33 overexpression or hypoxia further enhanced these gene expression, and ADAM33 overexpression plus hypoxia had the most significant expression-promoting effect; however, ADAM33 knockout blocked the promotion effect of co-culture on these gene expression, indicating that co-culture promotes fibroblast activation through ADAM33. Further detection of ferroptosis showed that co-BECs promoted the expression of GPX4 and FPN, and inhibited the expression of ACSL4; ADAM33 knockout down-regulated the expression of GPX4, FPN, FTH1 and FTL, while ADAM33 overexpression or hypoxia enhanced the regulatory effect of co-culture on these gene expression, and the synergistic effect of ADAM33 overexpression and hypoxia on co-culture was more significant. In addition, co-BECs promoted fibroblast proliferation and migration, increased GSH content, and reduced MDA production and cell apoptosis; ADAM33 knockout significantly increased the accumulation of Fe2+, ROS and MDA, as well as cell apoptosis, while reducing GSH content, cell proliferation and migration; ADAM33 overexpression or hypoxia had opposite effects, and ADAM33 overexpression plus hypoxia had a more significant regulatory effect on these biological traits of fibroblasts. Therefore, epithelial cells can regulate the activation, ferroptosis, proliferation, migration and apoptosis of fibroblasts by enhancing the expression of ADAM33, indicating that ADAM33 plays an important role in fibroblasts.