c-DNA cloning of the extended lifespan gene for the nondividing human cells

衰老是大多数多细胞生物在发育和体内平衡过程中一个重要的衰老过程。在人体内，有些细胞，如神经元和骨骼肌细胞，根本不分裂；其他细胞，如肝细胞，通常每一两年才分裂一次；而肠道中的某些上皮细胞每天分裂两次以上。我们已经建立了一个工作假设，即非分裂细胞的良好维护对于延长寿命更为重要。为了鉴定延长细胞寿命的基因，我们开发了一种利用cDNA表达文库的差异筛选方法。这使我们能够从一个非分裂的年轻细胞来源的cDNA文库中分离出一个克隆（els-1），该克隆在引入并在神经细胞中表达时表现出优异的延长寿命。

Senescence is an important aging process both during development and for homeostasis in most multicellular organisms. In the human body, some cells such as neurons and skeletal muscle cells, do not divide at all ; others, such as liver cells, normally divide only once every year or two ; while certain epithelial cells in the gut divide more than twice aday. We have built up the working hypothesis that the excellent maintenance of nondivideing cells are more important for longer lifespan. To identify the genes for the extended lifespan of the cells, we developed a diffrential screening method using cDNA expression library. This allowed us to isolate from a nondividing young cells derived cDNA library one clone (els-1) that exhibited excellent extended lifespan when in troduced and expressed in neuronal cells.