Scientists have found a way to reverse signs of ageing, including wrinkles and hair loss, in mice.
The mice's mitochondrial DNA had been artificially depleted, to mimic the ordinary loss of this DNA during the ageing process. The loss of mitochondrial DNA is linked to many of the external and internal signs of ageing. As a result, the mice lost much of their fur coats and developed pronounced wrinkles within weeks. But when scientists restored their mitochondrial DNA, the mice's skin once again became smooth and their coats grew back.
'To our knowledge, this observation is unprecedented,' said authors, led by Professor Keshav Singh from the University of Alabama at Birmingham in the US, in their paper published in Cell Death & Disease.
The recovery to healthy skin and coat was almost as rapid as the loss of condition had been. After two months of having artificially low levels of mitochondrial DNA, the mice regained their youthful appearance within a month.
'These experiments show that mitochondria are regulators of skin aging and loss of hair,' the authors write.
In addition to the visible signs of ageing, depleting the mice's mitochondrial DNA had several other harmful effects. The level of inflammation in the skin rose, with white blood cell presence boosted around the damaged and ailing skin cells and hair follicles. This inflammation decreased again when mitochondrial DNA was restored.
Other organs showed less dramatic changes, with an overall reduction in cell size the most consistent observation. The researchers now plan to test whether these shrunken cells can also be boosted back to normal size by reversing mitochondrial DNA depletion.
'This mouse model should provide an unprecedented opportunity for the development of preventive and therapeutic drug development strategies to augment the mitochondrial functions for the treatment of aging-associated skin and hair pathology and other human diseases in which mitochondrial dysfunction plays a significant role,' the authors concluded.