Feeling old? Telomere about it…..
2 months on from turning 24, I’m still finding it difficult to come to terms with the ordeal. It feels like yesterday when a younger friend turned to me and said “Jeees Phil tomorrow you’re seventeen! Gettin’ old man….” and now after a quick head-to-toe examination in the mirror, I take in the battle-wounds accumulated since; A freckle on my nose from when I squeezed a spot in earnest (probably a little too hard); A couple of shaving scars from whenever I obliterate my admirable attempt of a Confucius beard; A lower left leg scar gifted from the door of a deluded Taxi driver……..and a pair of ‘not-quite-fully-recovered’ ankles from when I battered the streets of London in the Marathon of 2009. Not a great deal to report on the exteriors to be honest. But deep inside the cells of the tissues of the organs of the Phil….things are going nutz!
Inside a cell, it’s virtually a whirlwind Blockbuster day-in and day-out. The genetic components in each of our cells, which provide the necessary information to produce proteins so you appear the way you do, are packed densely within chromosomes. Each of our chromosomes have “end-caps”, called telomeres, that play an important role in stabilising the end of chromosomes, because the ends of chromosomes tend to be a bit vulnerable you see (just like the outer penguins in a colony to the bitter cold). These telomere ends do not contain any active genes themselves but instead contain a variety of highly repeated DNA sequences and special proteins which form a unique structure at the end of a chromosome.
In my somatic cells, or more particularly – most cells other than my germ cells, circulating stem cell populations (haematopoetic cells for example) and my highly proliferative skin cells – my telomeres have gradually been getting shorter and shorter upon each division. As these cells divide throughout ageing, the ‘end-caps’ erode away causing the cells to malfunction or die. Only in those highly proliferative cell types are telomeres able to not only maintain their length but extend it, courtesy of a unique RNA transcriptase enzyme called telomerase.
Don’t get me wrong, there are perks to being 24 as opposed to 17 regardless of my depleting telomere lengths. Not having to put my hand up to go to the toilet is one of them! But there’s serious stuff to this business. Research leads us to believe that the telomere shortening mechanism sets a limit on the lifespan of a cell, thus heavily contributing to the process of ageing at a cellular level. Also, abnormalities in telomere regulation can lead to cancer – typically down to missed checkpoints on the path to senescence (limited replicative potential) as telomeres become shorter, and an overactivation of the enzyme telomerase.
So can we avoid cancers and keep our telomeres long?
A small pilot study published in The Lancet Onocology earlier this year suggests that making positive changes in our diet, stress management and social management may result in longer telomeres. Sounds optimistic, but worthy of our attention.
And so here’s to a long and happy life and a bright future full of youthful codgers……unless our Telomeres go AWOL.
Elizabeth Blackburn, Carol Greider, and Jack Szostak were awarded the 2009 Nobel Prize in Physiology or Medicine for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase.
I will certainly get around to that Will Smith & Ali post some-time soon!
- How science plans to help us live to 150 – and soon (talesfromthelou.wordpress.com)