肺脏的呼吸腺泡及其成体干细胞研究进展

Study on Respiratory Acinus of the Lung and Their Somatic Stem Cells

肺脏是机体与外界环境沟通的重要脏器之一,环境有害因子如病原微生物和致癌物可以直接损伤呼吸道上皮,对这类损伤的修复功能主要由呼吸道上皮内的肺干细胞或其祖细胞承担。呼吸系统的基本结构单位是呼吸腺泡,其表面积约占呼吸系统总面积的99%以上,是呼吸系统疾病包括恶性肿瘤发病的主要区域。现有证据显示,在肺脏的胚胎发育期,呼吸腺泡源自远端干细胞,在成体肺脏内此类肺干细胞主要分布在细支气管分叉处以及细支气管与肺泡导管的连接处,其恶性转化是肺癌的主要发病机理。因此,探讨呼吸腺泡中肺干细胞的生物学特性,有助于深入了解肺癌的癌变早期分子机制并为肺癌防治提供有效靶标。

The lung is one of the most important organs which connect to the environment. The environmental adverse factors, such as pathogenic microorganisms and carcinogens, can directly injure the respiratory epithelium, and the lung stem cells or their progenitor cells along with the respiratory epithelium assume the respiratory capacity for the injury. The basic structure unit of respiratory system is respiratory acinus. The surface area of the units constitutes of more than 99% of the total area of the respiratory system, so the respiratory acinus has an increased risk to develop respiratory diseases, especially malignant tumors. Evidence showed that, in the embryonic development of the lung, respiratory acinus originates from the distal stem cells which predominantly locate in the epithelium of bronchiole and the bronchioalveolar duct junction. Their malignant transformation represents a key mechanism for lung carcinogenesis. Because of this, exploring the biological characters of lung stem cells in the respiratory acinus can help to understand the molecular mechanisms underlying the oncogenesis in the lung and, therefore, facilitate to detect lung cancer at early stages and to develop potential targets for its prevention and treatment.