How is cellular senescence related to aging?
As normal cells approach the end of their ability to divide, they incur hundreds of biological changes that affect virtually all of their activities. Many of these changes are similar, if not identical, to the kinds of changes that we see occurring in aging humans themselves. Thus, the study of cellular senescence continues to provide important clues to the aging process at the most fundamental level?the cell and even the pathways within the cell. One of those clues came in 2004 when Dr. Bernhard Maier and his colleagues at the University of Virginia demonstrated a direct link between p53, a tumor-suppression pathway that triggers senescence, and the insulin-like growth factor-1 (IGF-1), an important pathway linked to aging in mammals. The researchers actually focused on p44, which is expressed at low levels in mouse and human cells and is thought to interact with p53. They created transgenic mice that overexpress p44 and discovered that these animals showed signs of premature aging af
