Scientists at A*STAR'S Genome Institute of Singapore (GIS) and Institute of Molecular Biology (IMB), have made a breakthrough discovery in the understanding of lung regeneration. Their research showed for the first time that distal airway stem cells (DASCs), a specific type of stem cells in the lungs, are involved in forming new alveoli to replace and repair damaged lung tissue, providing a firm foundation for understanding lung regeneration.
Lung damage is caused by a wide range of lung diseases including influenza infections and chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD). Influenza infection induces acute respiratory distress syndrome (ARDS) which affects more than 150,000 patients a year in the US, with a death rate of up to 50 percent. COPD is the fifth biggest killer worldwide.
The team took a novel approach in tackling the question of lung regeneration. They cloned adult stem cells taken from three different parts of the lungs - nasal epithelial stem cells (NESCs), tracheal airway stem cells (TASCs) and distal airway stem cells (DASCs). Despite the three types of cells being nearly 99 percent genetically identical, the team made the surprising observation that only DASCs formed alveoli when cloned in vitro.
"We are the first researchers to demonstrate that adult stem cells are intrinsically committed and will only differentiate into the specific cell type they originated from. In this case, only DASCs formed alveoli because alveolar cells are found in the distal airways, not in the nasal epithelial or tracheal airway", said Dr Wa Xian, Principal Investigator at IMB. "This is a big advancement in the understanding of adult stem cells that will encourage further research into their potential for regenerative medicine."
Using a mouse model of influenza, the team showed that after infection, DASCs rapidly grow and migrate to influenza-damaged lung areas where they form "pods". These
|Contact: Siok Ming Ong|
Agency for Science, Technology and Research (A*STAR), Singapore