Why We Age And How Telomeres Work

Why We Age And How Telomeres Work

When cells divide, telomeres shorten, and bad things happen when telomeres get short. When a cell divides, the genetic material inside that cell needs to be copied. This is called DNA replication. During this process, enzymes that replicate a strand of DNA are unable to continue replicating all the way to the end, which causes the loss of some DNA.

As an analogy, think of DNA as a long roll of bricks and of DNA replication as a bricklayer walking backwards on top of a brick wall, laying a new layer on top of that roll. When the end of the wall is reached, the bricklayer finds himself standing on top of the bricks he’s supposed to replicate. But since he can’t put down a brick where his feet are, he steps back and falls off the wall, leaving the very end of the wall bare. As a result, the new copy of the wall is shorter.

Just like this brick wall was copied imperfectly, our DNA is unable to copy itself perfectly. When a strand is replicated, the new strand is shorter than the old strand. Now what we’re trying to do is we’re trying to figure out a way to prevent that shortening and actually relengthen telomeres.

How can we prevent telomere shortening? Our reproductive cells have no telomere shortening, and this is why our children are born younger than we are, because our reproductive cells have no ageing process, so in trying to understand why this happening in our reproductive cells, we discovered an enzyme called telomerase.

Telomerase relengthens telomeres. Every time a reproductive cell divides, the telomere still gets a little bit shorter, but then telomerase relengthens it. In our research, we’ve discovered if we had more telomerase, the telomeres actually get longer and the ageing in the cells actually gets reversed; the cells become younger.