What causes cells to age?

What causes cells to age? 

Scientists have recently discovered an unexpected role for a protein that they associate with premature aging. They have shown that it is a main regulator of cellular senescence and have argued that its loss leads to normal aging.
Aging is an inevitable part of our life. But an increasingly aging population poses challenges to public health.

According to the Centers for Disease Control and Prevention (CDC), the number of people in the United States over the age of 65 will reach about 71 million over the next 10 years.

But what really happens when we age? Scientists are working on a number of theories.

Researchers at the Institut Pasteur in Paris, France, studied a protein called Cockayne B Syndrome (CSB), which is involved in repairing damaged DNA and premature aging.

Writing in the journal Nature Communications, the team explains that the levels of this protein naturally decrease with cell aging, starting a process known as cell senescence.