Aging Process Is Similar to Replicating CDs: Story of Telomeres

 

Why do we age? What is it that makes us age and grow saggy? How can we bring our youthful glow into adulthood and beyond? These are the questions that most women ask themselves. Joking, scientists and men alike ask the same questions. And you might find your answer in telomeres.

 

Brief Intro to Telomeres

 

Human cells divide at an average of 50-60 times in one lifespan. Every time they divide, the cell’s DNA has to be replicated. That way, a new chromosome can form and be used in the newly duplicated cell. However every time a cell duplicates, it comes at a cost. That is, the chromosomes get shorter and shorter. If they get short enough, the chromosomes can have their twining undone and our genetic data gets corrupted. Eventually, that cell dies.

Fortunately, chromosomes are like shoelaces with plastic caps. These plastic caps are what keep the shoelaces from getting undone. Chromosomes have their own plastic caps too. They are called telomeres. They are the extra DNA strands that a chromosome can afford to lose. They are what keep chromosomes from getting corrupt. So why are we not immortal? This is what an article from the University of Utah has to say about telomeres and division:

Yet, each time a cell divides, the telomeres get shorter. When they get too short, the cell no longer can divide and becomes inactive or “senescent” or dies. This process is associated with aging, cancer and a higher risk of death. So telomeres also have been compared with a bomb fuse.

 

They help to preserve genetic data when cells replicate in order to have fully functional healthy cells. RNA molecules are necessary in the process of copying DNA strands. Telomeres get shorter each time because these small RNA pieces need room on top of newly formed chromosomes.

Without telomeres, the ends of chromosomes would look like broken DNA, and the cell would try to fix something that wasn’t broken. That also would make them stop dividing and eventually die.

Telomerase, Cancer, and Aging

 

So is there something that keeps telomeres from disappearing? Actually there is an enzyme called telomerase. They fit on top of telomeres and are more prevalent in the younger years, however they also eventually disappear.

This is not the case for cancerous cells. Cancer cells activate the telomerase enzymes once the telomeres get dangerously short. This keeps the cancer cell’s DNA intact and allows them to multiply like mad dogs. In fact, measuring telomerase may be a new way to detect new cancer threats. If we learn how to stop telomerase from being activated, we may be able to make cancer cells experience aging just like healthy cells.

 In one experiment, researchers blocked telomerase activity in human breast and prostate cancer cells growing in the laboratory, prompting the tumor cells to die. But there are risks.

Shorter telomeres are related to shorter lives. Unfortunately, there is no strong evidence yet that shows that telomerase can make cells immortal and prevent aging. There is also no strong evidence that raising telomerase levels would also trigger cancerous cells to form.

Laboratory tests have shown though that telomerase was able to keep human cells divide far beyond the average limit without becoming cancerous. If researched further, we can have a future where human cells can be mass produced for transplantation, especially in key roles such as cells that produce insulin for diabetes patients.

Sources:

Genetic Science Learning Center. “Are Telomeres the Key to Aging and Cancer?.” Learn.Genetics 12 March 2013 http://learn.genetics.utah.edu/content/begin/traits/telomeres/

 

To be Fat or Not to be Fat?

America is fat, but it may also be healthy. A recent study on over weight individuals has sparked a lot of criticism. Katherine Flegal, a senior research scientist at the Centers for Disease Control and Prevention (CDC) says:

We published an article in 2005 that showed, among other things, that (being) overweight was associated with lower mortality.

Since then, Flegal and her associates have been working on a study that involves reviews of over 100 previous studies linking weight and mortality. The study claims that those who are overweight but not obese might be able to live through medical crisis’ better than those who are thin. The idea is that you lose weight when you are facing something serious, be it stress or a medical problem, and that those with more fat on them can shed 20lbs without much impact on their body. However, if you are thin and you lose 20lbs you end up straining your body and energy which can worsen your health, ultimately causing a pre-mature death.

It might also have to do with the mentality of individuals. A healthy thin individual may not be as inclined to see the doctor as often as an overweight individual might. Let us say for instance that both a thin and an overweight individual has a dormant tumor. The overweight individual may detect it sooner due to more frequent checkups than the thin individual simply because of the “I’m healthy I don’t need to get a checkup” mentality. Not to mention the stubbornness of not seeing a doctor for routine checkups because it costs too much. I think it all boils down to living healthier lives and paying attention to your body! Experts say that ultimately it comes down to how you feel, if you are overweight but fit and you feel good then you are healthy! 

The obese make us fat Americans average, does that mean that the average sized people will live longer lives? What do you think? Maybe its time to stop hitting the gym and time to start eating more pies! Chocolate pies, raspberry pies, banana cream pies, mint pies, key lime pies….. mmmmm so many PIES!

 

Sources:

http://edition.cnn.com/2013/01/02/health/overweight-mortality/index.html

http://www.helpguide.org/harvard/mindfulness.htm

http://www.cdc.gov/nchs/fastats/overwt.htm