Type II alveolar epithelial cell (AT2 cell or AEC2)

Type II alveolar epithelial cells (AT2/AEC2) are cuboidal cells in the lung alveoli responsible for synthesizing and secreting pulmonary surfactant, which is essential for lowering surface tension and preventing alveolar collapse. Critically, they serve as the principal resident stem/progenitor cell population for the alveolar epithelium, capable of self-renewal and differentiation into type I alveolar epithelial cells (AT1) following lung injury. These cells are regulated by a complex interplay of intrinsic factors (e.g., transcription factors like NKX2-1) and extrinsic niche signaling (e.g., Wnt, FGF, HGF, EGF, S1P pathways). Damage to the alveolar epithelial barrier is implicated in diseases such as ARDS and pulmonary fibrosis. Promotion of AT2 cell regeneration is a central therapeutic goal in lung injury, but it is not a single molecular target, and the process involves multiple molecular pathways, cell types, and paracrine interactions[1][2][3][4][5].

Other names

alveolar epithelial progenitor cellAEC2AT2 celltype II pneumocytealveolar stem cell

Promotion of AT2 cell proliferation and differentiation into AT1 cells (by niche factor modulation or pathway inhibitors/activators)[1][4][5]