Scientists find a way of rejuvenating old cells to make them young again

Reversing aging could be a step closer after British scientists discovered what causes it.

For the first time Newcastle University scientists have found a possible way to rejuvenate old cells back into younger ones. They conclusively proved that mitochondria, the batteries of the cells, are essential for aging.

When mitochondria were eliminated from aging cells they became much more similar to younger cells.

The discovery that mitochondria are major triggers of cell aging brings scientists a step closer to developing therapies to counteract the ageing of cells by targeting it. Mitochondria are often referred to as the powerhouses of the cells as they generate the energy that our cells need to do their job.

The study noted as we grow old, cells in our bodies accumulate different types of damage and have increased inflammation, factors which are thought to contribute to the aging process.

A series of genetic experiments involving human cells grown in the laboratory successfully eliminated the majority, if not all, the mitochondria from ageing cells. Cells can normally eliminate mitochondria which are faulty by a process called mitophagy.

Scientists 'tricked' the cells into inducing this process in a grand scale, until all the mitochondria within the cells were physically removed. Surprisingly scientists then saw the aging cells, after losing their mitochondria, showed characteristics similar to younger cells, that is they became rejuvenated.

The levels of inflammatory molecules, oxygen free radicals and expression of genes which are among the makers of cellular ageing dropped to the level that would be expected in younger cells.

Lecturer Dr João Passos of the Institute for Aging said: 'This is a very exciting and surprising discovery.

'We already had some clues that mitochondria played a role in the ageing of cells, but scientists around the world have struggled to understand exactly how and to what extent these were involved.

'These new findings highlight that mitochondria are actually essential to the ageing of cells.'

The study led by Newcastle University and involved other UK and US teams also deciphered a new mechanism by which mitochondria contribute to aging. It identified that as cells grow old, mitochondrial biogenesis, the complex process by which mitochondria replicate themselves, is a major driver of cellular aging.

Research Associate Dr Clara Correia-Melo said: 'This is the first time that a study demonstrates that mitochondria are necessary for cellular ageing.

'Now we are a step closer to devising therapies which target mitochondria to counteract the ageing of cells.'

The study was published in the EMBO Journal.