Mitochondria linked to the ageing process

Mitochondria are the little energy factories inside every cell in our body. They even have their own DNA, and its number can reach thousands of copies in a single cell. But not all mutations in mitochondrial DNA are immediately visible – some of them are very hidden and only show up in individual cells.

Researchers from Imperial College London for the first time were able to look at these ‘invisible’ mutations at the level of individual cells. They found that as we age, the number of these hidden changes in mitochondria increases – and this coincides with the times when our bodies start to show signs of ageing.

The peculiar thing is that aging is an uneven process. Sometimes it seems that we are still awake and full of vigour, and then suddenly we start to feel a decline. It is this non-linear development that scientists have found in mitochondrial mutations: their accumulation occurs intermittently, sharply increasing in those periods when the body begins to ‘age’.

Why exactly mitochondria? These ‘energy stations’ are responsible for the work of all tissues and organs. It is known that mutations in their DNA can cause serious diseases and accelerate the appearance of signs of aging. Mice with an increased rate of mitochondrial mutations, for example, lose their hair and wrinkle much earlier.

Until recently, scientists could not see these mutations in human cells – conventional methods of analysis showed only an ‘average picture’ of the whole organism. Now technologies allow to consider each cell separately and notice even the rarest and most hidden mutations.

It is worth noting that scientists do not yet claim that these mutations directly cause aging. Rather, their accumulation serves as a ‘predictor’ of how the body changes with age. Nevertheless, animal experiments confirm that mutations in mitochondria do affect the aging process. Interestingly, we are not talking about a single mutation, but about many different changes, which together form a hidden layer of aging at the cellular level.