Logan Catriona Y, Desai Tushar J
Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA.
Department of Internal Medicine, Pulmonary and Critical Care, Stanford University School of Medicine, Stanford, CA, USA.
Bioessays. 2015 Sep;37(9):1028-37. doi: 10.1002/bies.201500031. Epub 2015 Jul 22.
The application of in vivo genetic lineage tracing has advanced our understanding of cellular mechanisms for tissue renewal in organs with slow turnover, like the lung. These studies have identified an adult stem cell with very different properties than classically understood ones that maintain continuously cycling tissues such as the intestine. A portrait has emerged of an ensemble of cellular programs that replenish the cells that line the gas exchange (alveolar) surface, enabling a response tailored to the extent of cell loss. A capacity for differentiated cells to undergo direct lineage transitions allows for local restoration of proper cell balance at sites of injury. We present these recent findings as a paradigm for how a relatively quiescent tissue compartment can maintain homeostasis throughout a lifetime punctuated by injuries ranging from mild to life-threatening, and discuss how dysfunction or insufficiency of alveolar repair programs produce serious health consequences like cancer and fibrosis.
体内遗传谱系追踪技术的应用，加深了我们对肺等更新缓慢的器官中组织更新细胞机制的理解。这些研究已鉴定出一种成年干细胞，其特性与维持肠道等持续循环组织的传统认知干细胞截然不同。一幅由细胞程序组成的图景浮现出来，这些程序补充气体交换（肺泡）表面的细胞，从而能够根据细胞损失程度做出相应反应。分化细胞进行直接谱系转换的能力，使得损伤部位能够局部恢复适当的细胞平衡。我们将这些最新发现作为一个范例，展示相对静止的组织区室如何在一生中经历从轻度到危及生命的各种损伤时维持体内平衡，并讨论肺泡修复程序的功能障碍或不足如何导致癌症和纤维化等严重健康后果。
