Mole rats are now being studied with increased interest because of their unusual long life. Although not much larger than a standard rat, they boast an average lifespan that is 10 times larger than their counterparts. They were originally admired as the one of the few mammals to live within social groups but now scientists realise that they may start the research and development for the elixir for life.
Oxidative stress is thought to play a large part of the human ageing process and scientists think that it is this that the mole rats are countering to live so long. During oxidative stress, the telomeres on the end of DNA chromosomes react with some of the products from metabolism- free radicals. These are chemicals which, for you chemists out there, have an unpaired electron in the outer shell that makes them extremely reactive. Over time, typically 70 years in humans according to Wikipedia, the telomeres shorten and disintegrate as they react with the radicals. As a result the cell cannot replicate and cell death occurs which leads to ageing. Knowing this, It doesn't take a genius to work out the theory of eternal life- lengthen these telomeres then you lengthen your life. In spite of this, mole rats have actually been found to have even shorter telomeres in their own chromosomes than in mice of the same age who only live for a mere 3 years in captivity.
Maybe it is their immunity to cancer that allows them to reach such an elderly state- yes- mole rats have never developed the tumours that cause the death of 6.7 million people worldwide each year. Suddenly Mole Rats don't look so ugly.
It is due to the sensitivity of the mole rat cells that give it anti-tumour properties, scientists think. Human cells, and indeed mice cells, all show the phenomenon of contact inhibition whereby cell replication is disabled and is caused by cell-cell contact. This means that the cells are never too dense, something that would occur if the cells became cancerous. Cancerous cells have no contact inhibition, which means that they will replicate an infinite amount of times. As a result, humans cells will shut down when they are too densely packed and the cancer is prevented. In mole rats, however, the cells are hypersensitive to being dense and are observed as inhibiting cell growth earlier than human cells (aptly named "early contact inhibition") which makes them especially resistant to a tumour. Scientists think they will be able to turn on the phenomenon on in humans if they find out the physiological mechanism behind "early contact inhibition" is a extracellular molecule. This could then be implemented into an injection. That is a big "if" ,however, and there is still a long way to go to find out the elixir for immortality.
My question is- why don't scientists just ask Legolas?
No comments:
Post a Comment