[Research progress on the proliferation and differentiation of type Ⅱ alveolar epithelial cells]

The alveolar epithelium consists of two types of cells: alveolar epithelial type Ⅱ cells (AT2) and alveolar epithelial type Ⅰ cells (AT1), which function to maintain lung compliance and gas exchange, respectively. AT2 can proliferate and differentiate into AT1 during lung development and repair, thus AT2 have been regarded very important stem cells in lung. However, impaired proliferation and differentiation of AT2 were observed in many chronic lung diseases, preventing the proper repair of alveolar and significantly impacting the life quality of patients. This review focuses on when AT2 proliferate and differentiate, and highlights the critical signaling pathways that influence these processes.