DNA is fascinating. I have spent nearly twenty years getting inside this dynamic molecule, the basic component of human life, that controls hair colour and how long you will live and everything in between.
Every cell in the human body contains this miracle molecule. It's wound up inside the nucleus and can respond to our changing environment. For example, in work I have recently completed, I have been able to measure the rate of response of DNA to conditions mimicking inflammation in the wall of the peripheral blood vessels. Put simply, I created a laboratory model of atherosclerosis, which as you know is a thickening of the arteries, leading to heart attack and stroke. These experiments were important to do because they showed us how the DNA functions in cells from individual people with different DNA variations.
DNA is divided into functional regions, which we call genes. These genes contain naturally occurring variations, which makes us different from one another. Many of these variants are completely compatible with normal life; that is, the cell will grow and divide in the normal way. This is different from mutations such as those in cancerous cells, which cause aberrant cell proliferation and division.
In order for a region of DNA to respond to a signal from outside the cell, it must be in a relaxed or open state. A number of carrier or transport molecules including cytokines are responsible for presenting the stimulus to the open DNA molecule, in the correct functional position or gene. Once this has happened, the region of DNA closes, a bit like pushing a spring between your hands. In this closed the position, the function of the gene is turned off and no other molecules can interact with the DNA. Imagine a very fine orchestra with a very busy conductor making sure that nothing goes out of tune. All these processes happen without our conscious intervention, and that is what makes DNA fascinating.
Techniques developed in the laboratory by some very clever scientists have allowed us to visualise these processes. We can measure them and discern differences in them between different people, who have different gene variants. Thus, we can say that genetics can determine an individual's response to inflammation. But what do we do with this information. Well, in the not too distant future scientists would like to translate this research into the clinical setting so that family and hospital doctors may be able to look at our genetics when deciding on treatment.
Next time, RNA unplugged and proteins unmixed.