Your jeans/genes are sexy and they remember!

What do my favourite jeans remember?  What did I do to my genes while I was wearing them? 

Every girl has her favourite pair of jeans.  The pair that you just know you look hot in.  With women’s bodies coming in all curves and sizes, finding that pair can take some time.  My favourite pair are really old: a pair of an unusual blue-coloured Calvin Klein Tencel jeans that make me feel like I am wearing butter.  Perhaps not the best description, but I will never forget the first time I tried them on.  They were so soft, so soft it prompted me to ask the salesperson to confirm they were in fact jeans.  She smiled and replied that they were made with a new material called Tencel… yes they are that old… and that Tencel accounted for the softness.  Okay, here’s where I out myself and admit I have not worn them that much.  Why haven’t you worn them to death Sage?  Because they are one of my favourite items of clothing and I want them to last forever.  Silly, I know!  I save them for special occasions.  Yeah, that means cute boys!  I have received some really nice kisses in those jeans!  I have been on some really memorable dates in those jeans.  One of my memories in those jeans occurred while dating a boy named Scott, a big hunk of a guy who was really funny and very kind.  We went out to dinner and then dancing one night.  Afterward, when we walked back to his car, we passed through this square of sorts that various buildings backed onto.  As we did, we encountered this outdoor restaurant all light up with tiny white lights.  There was not a single customer at the restaurant, but they were still playing music, music loud enough to dance to…sexy music.  It was a very unobvious place to dance but I was so attracted to that boy at that moment that I asked him to dance.  We danced until they turned the music off.  There was something magical about that night.  I was in a huge city and there was inexplicably not a soul within sight, except us.  I was drunk with happiness that night. 

Nights like that were a sharp contrast to how I was treated when abused. 

So tonight, I find myself wondering, which of those events wrote on the slate of my genes, the dancing and kisses under the white lights or the abuse…or perhaps both?  Your jeans/genes remember!

Epigenetics baby!

I am not a science geek but that one science term makes me want to go back to school and study genetics.  It also makes me want to live until I am a hundred so I can read about everything that is discovered about the epigenome.  In fact, I would serve myself up so they could study mine.

What is epigenetics you ask?  Well, if you haven’t yet heard that word, know that one day you will hear about it a great deal.  You may not understand it at first, but the scientific information discovered from it will make you sit up and pay attention.

According to the Human Genome Project we have approximately 25,000 genes in our DNA.  These genes which are segments of DNA each make specific proteins.  These proteins build, regulate and maintain your body.  However these genes need instructions in order to act.  Those instructions are the chemical markers and switches that turn on and off the expression of our genes and they make up our epigenome.  Patterns of chemical modification are called epigenetic tags.  Our genome has now been mapped by the Human Genome Project.  Our epigenome, which will be harder to map, has not.

DNA is about the genes you inherit from your parents.  Epigenetics is about how those genes are expressed and while science at one point did not believe so, we now know you can inherit those gene expressions, those epigenetic tags, from your parents as well…our genes remember!

Speaking of memory…I remember clearly as a child wondering why a set of identical twin sisters Grace and Fiona, who I knew from birth, were different in some very noticeable ways as they grew up, when even their mom could not tell them apart as children.  My young brain assumed that because they were identical they had to always remain so.  Yes, they were genetically identical, but were Grace and Fiona epigenetically identical?  They had the same genome but had their epigenomes expressed individually and differently?

What do we know so far about our epigenome?

We know that it responds to our environment.  This fact alone makes two pieces of epigenetic research interesting to a girl who was abused.

1. Using a rat model, infant maltreatment by a caregiver was investigated to determine whether early-life adversity leaves lasting epigenetic marks. Infant rats were exposed to stressed caretakers that predominately displayed abusive behaviours.  Researchers assessed DNA methylation patterns* ^{(see explanation below)} (a type of epigenetic mark) and gene expression throughout the life span as well as DNA methylation patterns in the children of the abused rats.  What they found was that early abuse by the mother rats produced persisting changes in methylation that caused altered gene expression in the adult prefrontal cortex resulting in more anxious children. In addition, they observed altered DNA methylation in the children of the abused rats.  This research concluded that early abuse and neglect caused lifelong and transgenerational changes in gene expression. 

*DNA METHYLATION

1. A chemical coating on DNA that determines how our genes work.

2. At conception you have a particular pattern of DNA methylation that you received from your parents. While our DNA sequence is very static  from one generation to the next, the methylation pattern changes regularly, and differently in different organs.

3. Methylation does not change the qualitative nature of gene sequences (like gene mutations do) and protein products function the same whether or not the gene was methylated . What does change is the frequency at which a protein is expressed from a gene template which is altered by the methylation.

4. These methylation changes accumulate over time and are often gene and organ specific.  For example: by comparing the methylation state of a gene in say brain cells to that in liver, muscle or other cell types (or to "the average persons brain cells") you can deduce what has abnormally built up since birth.

2. Researchers studied the brains of suicide victims in order to explore the link between childhood abuse and adult suicide.  What they found was that childhood abuse amongst suicide victims was associated with a distinct epigenetic mark on the DNA. 

Their research involved examining brain samples from three different groups.  One third of the samples came from suicide subjects who were known to have been abused as children, one third came from suicides with no known childhood abuse, and one third from a control group. The researchers discovered that the suicide victims who had suffered childhood abuse had specific epigenetic methylation characteristics missing on specific DNA sites that were in the other two groups. Those epigenetic marks were shown to influence hypothalamic-pituitary-adrenal function which is a critical feature of the stress response.  Hypothalamic-pituitary-adrenal function is managed by a set of genes expressed in the hippocampus, including one that was epigenetically marked by the experience of childhood abuse. Abnormal HPA activity in response to stress is in turn strongly linked to suicidal action.

Even though we do not have any information yet to make specific epigenome-healthy changes to our lives yet, what we know so far has me convinced that everything we do matters. 

It has even provoked me to make my first New Year’s resolution.  I have never understood the point of New Year’s resolutions let alone ever considered making one before now.  Similar to the sleep challenge made by The Huffington Post this new year, I have committed to going to bed at the same time every night.  I have a long history of sleeping problems.  That said, I have slept better than my many year five hours a night, for a while now, but it is fair to say that I still do not sleep well enough.  I haven’t lived on a 24 clock, which I understand to be important for your circadian rhythms.  So, I have decided to make that change.  I feel committed so I am quite hopeful, but I cannot say I like it so far.  I am hoping it will stick, so I can see longer term if I notice any difference.  Epigenetics has me considering making other changes as well.

It is fascinating to me that we are on the brink of understanding that possibly everything we do and experience in our lifetime modifies the expression of our DNA and in some cases, at the very least, those of our children and our children’s children as well.  As research teaches us more about our epigenome, we will eventually be given opportunities to decrease our risk of disease.  The implications that will arise from understanding the true causes of disease, including those in our social environment, may be enormous.  Perhaps we will even be able to reverse the changes and thereby repair the would be damage caused by both our lifestyle and that our of grandparents.

Your favourite pair of jeans have always been sexy.  Your genes are about to get a whole lot sexier!

Next Blogum: February 2010

Sage Spencer