Alveolar epithelial cell (AEC)

Alveolar epithelial cells (AECs) are the specialized cells that line the pulmonary alveoli, facilitating the vital process of gas exchange. They are categorized into two main types: Type I (AT1) cells, which cover approximately 95% of the alveolar surface area and are essential for the blood-air barrier, and Type II (AT2) cells, which secrete pulmonary surfactant and serve as progenitor cells for the alveolar epithelium (StatPearls, 2023). AT2 cells also play a critical role in ion transport and immune regulation within the lung microenvironment (Nature Reviews Molecular Cell Biology, 2022). In diseases such as Idiopathic Pulmonary Fibrosis (IPF) and Acute Respiratory Distress Syndrome (ARDS), AEC dysfunction or depletion leads to impaired gas exchange and structural remodeling (American Journal of Respiratory and Critical Care Medicine, 2020). While the cell itself is not a single molecular target, it expresses various receptors and transporters, such as the epithelial sodium channel (ENaC) and ACE2, which are targeted by pharmacological agents to manage fluid balance or viral entry (Journal of Biological Chemistry, 2019; Cell, 2020). Consequently, AECs are a focal point for pulmonary drug delivery and regenerative medicine research.

Other names

PneumocyteAlveolar cellType I alveolar cellType II alveolar cellAT1 cellAT2 cell

Drugs interact with alveolar epithelial cells by replacing deficient surfactant, inhibiting ion channels like the epithelial sodium channel (ENaC) to regulate fluid clearance, or activating beta-2 adrenergic receptors to stimulate surfactant secretion and fluid reabsorption (StatPearls, 2023; PubMed, 2021).