Novel gene fad104 is required for lung morphogenesis

Abstract

Previously, we identified fad104 (factor for adipocyte differentiation 104) as a novel gene whose expression was induced in the early stage of adipogenesis. Mouse fad104 encodes a 132‐kDa protein, which contains nine fibronectin type III domains and a transmembrane region. We have reported that fad104 promotes adipogenesis and that deletion of fad104 causes neonatal death. However, the cause of death in fad104‐deficient mice is unclear. Here, we attempted to clarify the cause of death in fad104‐deficient mice, and uncover the physiological role of fad104.□@ First, phenotypic and morphological analyses showed that fad104‐deficient pups displayed cyanosis and died from respiratory distress immediately after birth. In addition, fad104‐deficient lungs were small and its alveolar spaces were not dilated adequately. Furthermore, we revealed that FAD104 was expressed in alveolar epithelial type II (ATII) cells in the developing lungs. Moreover, the ATII cells in fad104‐deficient lungs were immature and attenuated the expression of surfactant‐associated proteins.In conclusion, this work demonstrated that fad104 has a crucial role in lung morphogenesis at least in part by regulating ATII cell maturation.