Getting rid of senescent cells —— it's not just for the elderly

The accumulation of senescent cells has long been thought to be a phenomenon unique to old age, but is this really the case? To answer that question, we need to understand what causes senescence of cells. Hayflick limits point out that with the increase of cell division, telomere DNA gradually shorts, which eventually leads to the cell stopping division and proliferation and entering the senescence state (Figure 1). From this point of view, the increase of age is indeed the main cause of cellular senescence.

Figure 1. Senescence-Centric View of Aging [1].

 

However, cellular senescence is a complex process involving multiple factors. More and more research show that the accumulation of cellular senescence is not limited to the elderly. In addition to age, there are a number of other factors that can also cause cell aging. Some common factors include environmental factors, lifestyle, metabolic processes, and the development of chronic diseases. It is no exaggeration to say that there are "catalysts" that accelerate cellular senescence everywhere in our lives:

 

  • Environmental factors: Such as exposure to harmful chemicals or radiation, can cause damage to cells and accelerate the aging process. There are an intuitive example of photoaging, a truck driver exposed to sunlight on the left side of his face for years, it is evident that his left face has more wrinkles and more aging than the right [2] (Figure 2).