Sociology and stem cells: a lesson in natural self-healing and why some of us may be better at it

Author: Holly Wobma, 05/13/14

>
I think one of the most universally embraced ideas when people gather together and pontificate about how their relatives or colleagues turned out they way they did, is that ‘people are a product of their environment’.

I’m not here to make a singular stand against this notion — in fact, it certainly can explain some health outcomes. Consider the following statements:

Parents of higher socioeconomic status may provide healthier food for children.

Being educated about health risks can enable people to make better lifestyle decisions.

These statements emphasize that our social environment can affect our well-being by affecting our choices.

However, this really only scratches the surface. Because social environment not only affects our choices, but also our underlying biology.

In particular, an article in last month’s issue of the Proceedings of the Natural Academy of Science, (PNAS) highlights the specific role of social stressors on genetic structures called telomeres.

Let me explain…

Every time our cells divide, a little bit of DNA gets left out at one end of the chromosome. Yes we lose genetic material! We evolved to have a biological buffer against this – our chromosomes are capped with a DNA sequence called a “telomere”, a series of TTAGGG repeats, which serves as a genetic martyr. Instead of losing critical genes each time our cells replicate, we lose telomere repeats. The telomere, therefore, protects the integrity of our genes, and the consumption of telomere length over our lifetime is associated with cell senescence, physiological aging, and the risk of premature death.

This month’s PNAS article is interesting because it studied how telomere length in African American boys is affected by social environment, taking into consideration economic status, parenting quality, family structure, and maternal level of education. The investigators’ model found that a disadvantaged environment was associated with a 19% shorter telomere length in 9-year old boys. Interestingly, they also show that this difference in telomere length between children from advantaged and disadvantaged environments is affected by the child’s alleles for neurotransmitters important in mood, reward, and behaviour. Having specific alleles (versions of genes) predisposed children to having telomere shortening in the setting of a disadvantaged environment. Basically, our genetics affect how our telomeres respond to social stressors.

Now one category of cells in which the telomere is an absolutely critical structure is the stem cell. If you consider that the most basic features of stem cells are 1) the ability to differentiate into multiple tissue types and 2) the ability to maintain replication, it is this latter characteristic that requires telomeres to be intact. In fact, stem cells are fairly unique in their expression of telomerase, an enzyme that helps to continuously rebuild their telomeres.

Nevertheless, similar to other cells in our body, telomere shortening can and does occur in stem cells, and it can impair their ability to mobilize when needed for tissue repair, as well as disturb their local microenvironment. It’s aging at the level of the tissues!

Taking this information in context with the current study, it would seem that our social environment can affect the functioning of our stem cells, by affecting the length of their telomeres. Furthermore, it could be postulated that people have different genetic susceptibilities to telomere shortening in their stem cells.

It may not be possible to alter our genetic susceptibility or even the degree of social stressors we experience. However, I can’t help but indulge in the idea that whatever healthy lifestyle options I make for myself, they are healthy for me because they are “good for my stem cells”.

The following two tabs change content below.
Holly Wobma

Holly Wobma

MD/PhD student at Columbia University
Holly is an MD-PhD student at Columbia University in New York. She recently (2011) completed a Bachelor of Health Sciences Honours Degree from the University of Calgary, where she pursued research related to nanotechnology and regenerative medicine. In addition to research, she enjoys participating in science outreach roles. Previously, she contributed to an award-winning Nanoscience animation produced by the Science Alberta Foundation (“Do You Know What Nano Means?”), and served on the board of directors for the Canadian Institute for Photonic Innovations Student Network. Holly's lab tweets @GVNlab.
Tags: , , , , , ,

5 Responses

  1. Jim Hardy says:

    Wow. What a bunch of crap. Do you have data? This is not science, this is mere hyperbole. Please do not represent yourself as a credible stem cell researcher unless you can demonstrate something of substance.

  2. Lisa Willemse says:

    Dear Jim,
    Glad you are reading the blog and we thank you for commenting and for the question you raise. The value in the comments thread is that it provides an opportunity to question, support or provide additional insights to a topic presented by our bloggers.

    We do, however, ask that comments keep a level of professionalism and mutual respect as part of this process. Accusations and strong language levelled towards a blogger regarding the quality of their work or credibility is not a foundation upon which to foster an open exchange of ideas.

    Lisa Willemse
    Co-editor

  3. PRice says:

    I found several questionable areas in this study. The largest is the way the researchers arrived at the concluding sentence, “We suggest that an individual’s genetic architecture moderates the magnitude and direction of the physiological response to exogenous stressors.” They deliberately skewed the experimental 40-person sample, then made “findings” by pretending that contrasting two 20-person skewed samples of 9-year old boys represented something about stress and genetics in a larger population of children without proving their case.

    Researchers cannot validly do this in children’s brain studies, for a comparable example. It is well known that long-term stress causes a child’s brain to develop differently than an unstressed child’s brain.

    Further, instead of establishing a control group, the researchers split their sample according to maternal depression, which is an experimentally proven contributor to epigenetic changes detrimental to a developing fetus and on to infancy and early childhood. There are dozens of studies on that subject from which to choose on PNAS.org.

    So, of course, in general “..an individual’s genetic architecture moderates the magnitude and direction of the physiological response to exogenous stressors.” But the researchers didn’t do the work to find out whether it was the genetic architecture that the 9-year-olds were epigenetically changed into, or the genetic architecture they were conceived with, that stored the damage. I presume that this additional work wasn’t pursued because those type of findings wouldn’t make the race-baiting headlines of the press coverage this study was designed for.

    Which leads me to ask – Was this study published to further an agenda other than make a contribution to science?

    If so, does this study also represent a failure of the peer review process? Were the reviewers even interested in advancing science?

    http://surfaceyourrealself.com/2015/02/01/problematic-research-with-telomere-length-surfaceyourrealself/

Leave a Reply

*
*