Deoxyribonucleic acid (DNA), as we all know, is the over arching storage system of our cells that allow us to live. Without this storage system, or library of genes and genetic information we would be nothing; I wouldn’t be writing this at my home right know and you wouldn’t have the ability to be reading this. Because this fundamental structure is so vital to life there has to be some sort of protection mechanism, right? Well, there are many, but today I am talking only about one.
Telomeres are a simple idea in that they are the end caps of our chromosomes, but they are beautifully intricate in their importance and the mechanisms they play part in. A common analogy to telomeres is the shoelace example. Think of chromosomes as the lace part and telomeres as the plastic tips (Fun Fact: also called an aglet) that keep the lace from fraying. Telomeres do exactly that, they keep the important DNA in the chromosome from fraying and falling apart.
The structure of these end caps are quite simple in that it’s only a six base pair (A,T,C,G) sequence that repeats over and over again. This sequence varies based on the organism (the human sequence is TTAGGG) but the sequence typically repeats about 3,000 times and can extend up to 15,000 base pairs1.
These telomeres are on every one of our 46 chromosomes and each round of cell replication shortens the telomeres by 25-200 bases1. Compared to chromosoms without telomeres, important DNA would be lost at that same rate. Each cell goes through about 50-70 replications before it goes through senescence (cell aging) and eventually apoptosis (programmed cell death). This means that over the life of one cell you would lose 1,250-14,000 bases off your chromosomes. Imagine this happening for every cell in your body (the average person has ~30 trillion cells). That is a massive number that I’ll let you calculate. Nonetheless we would all die extremely quickly without telomeres solely due to lack of functional DNA.
https://www.tasciences.com/what-is-a-telomere/
Luckily it isn’t considered “game over” when telomeres deplete. There is an enzyme responsible for adding the repeats back onto the ends of chromosomes, and this little hero is called Telomerase. Telomerase is highly active in “germline” cells (eggs, sperm and stem cells) which is what allows new born children to have such high amounts of telomeres. Though, in somatic cells (body cells like skin, muscle, liver), telomerase activity is very low which is where problems start to occur with aging. The decrease in telomere length could also lead to oncogenic transformation, or cancer formation from somatic cells. These cancer lines can become immortalized through the over expression of telomerase to extreme levels, more than that of germline cells.
The depletion of telomeres can be expedited by some daily habits. Specifically, smoking is, as we all know, is a contributor to cancer. One of the ways it affects cancer is through telomere shortening. Obesity has also been shown to increase telomere degradation, or rather intake of polyunsaturated fatty acids (like linoleic acid). A negative correlation can be made between telomere length and waist circumference.
There are some ways to prevent telomere degradation. Exercise has also been shown to decrease DNA damage and limit telomere degradation. Overall limiting your caloric intake has a positive effect on aging, almost a 66% increase in lifespan has been seen. This has to do with decreasing the oxidative stress you put on your body. There is a lot of news about antioxidants being good for your health well it also is shown to increase lifespan by again decreasing oxidative stress on your body and DNA. The last option would be gene therapy.
A company from Seattle, called BioViva carried out the first anti-aging gene therapy on their own CEO, Elizabeth Parrish. The researchers reported a lengthening of her leukocyte (white blood cells) telomeres from 6.71 kilobases to 7.33 kilobases. This is a major breakthrough in the field of anti-aging because in this test there might have been 20 years of life added to Parrish’s DNA!!!
https://www.inverse.com/article/14614-gene-therapy-makes-bioviva-ceo-elizabeth-parrish-younger-blunter-and-resolute
So we are living in a time where the first steps of anti-aging is starting to take hold, and people like Elizabeth Parrish and her company are paving the way for future companies. I hope to one day be among them in this fascinating field and I hope telomeres have just started to peak your interest into the fascinating world of immortality.
Sources:
- http://www.yourgenome.org/facts/what-is-a-telomere
- http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3370421/
- http://www.the-scientist.com/?articles.view/articleNo/45947/title/First-Data-from-Anti-Aging-Gene-Therapy/
Hey!
Why am I not surprised your first post is on anti-aging? It’s a pretty interesting topic– I’m starting to read about it more and the lab techniques they’re using make for some decent reading. What got you interested in this subject?
The protein P53 has always been interesting to me and it stemmed from there. I find all mechanisms by which cells die and can live fascinating.
Interesting how daily behavior can effect your body on a molecular scale. (I’m not sure how else it would effect it, but it’s still interesting)
Did they check if or how the treatment affected Elizabeth Parrish’s other cell types?
I haven’t read anything about treatment effecting her other cells, but that is a definite concern to think about.
Wow! I had no idea telomeres were so cool! Now I understand why you are so passionate about the subject. I wanted to ask about the portion of your blog that you talked about regarding the company BioViva and their CEO, Parrish. Did you ever hear of any public outcry before, during or after she underwent this experiment to lengthen her telomeres? I know that the idea of anti-aging is a touchy subject for some and I’m curious as to what the public’s opinion is regarding this. Also, do you know what the process is in general that they used to extend her telomeres? Was there a “one-and-done” treatment or was this an extremely long trial for her?
These are good questions! I like your graphic–Elizabeth looks really intense. Check your link for the linoleic acid. See if that’s really what you wanted to show.