Have you ever noticed how fast your mouth wounds heal? For example, if you get burns due to drinking something too hot, the pain is usually gone in a few days. If you get a cut on your arm, it takes longer to heal. Why? What can this teach us about how your body heals?
Gene Expression Defined
To understand this new study, it’s important to understand what gene expression is. Your genes, as you may already know, are the instruction manual for everything in your body. However, there are parts of your genes that are used every day and parts that are silent.
Gene expression is how our genes are used. Meaning, which parts of your genes get to make the proteins your body needs. It’s this gene expression in our mouth cells that seems to be responsible for those fast healing mouth wounds. Let me explain.
Understanding Fast Healing Mouth Wounds May Lead to Faster Wound Healing in General
In a new study, researchers created two same-sized wounds on each of 30 participants. One in the mouth (along the inner cheek) and one on the skin of the arm. For six days, researchers observed the wounds, studied the tissue, and analyzed the molecular makeup. The results? They found that mouth wounds compared to skin wounds, for example, heal differently due to a specialized expression of the genes in mouth cells. It seems these cells are instructed to instantly be ready to heal, even before a mouth injury has happened; whereas, a skin cell, for example, doesn’t signal repair mechanisms until an injury occurs. Meaning, mouth cells have a good head start on healing.
A second part to the study was to isolate one of the specific proteins responsible for this quick healing (SOX2) and then overexpress that protein in the skin cells of mice to see if faster healing could be replicated in the skin cells. This was indeed the result.
So why is it so important that we know why mouth wounds heal so quickly? Because understanding why something happens in one area of the body can sometimes help science replicate a similar effect in another area of the body (such as researchers were able to do in the mice in the second phase of the study). In other words, if we understand why the mouth heals so fast, maybe we can use that knowledge to find a way to help wounds in other parts of the body heal faster.
More on Gene Expression
In addition to genes expressing themselves differently depending on the area of the body, gene expression may vary just based on an injury. Let’s move to the shoulder as an example. A small or large tear in the shoulder rotator cuff tendon demonstrates a different gene expression from a normal rotator cuff tendon. Genes instruct cells in the injured tendons to make proteins that break down tissue, and the cells also have less ability to signal new cells for repair and to make new tendon. Compare this to gene expression in the mouth cells that instructs them to make proteins that appear to be responsible for fast healing when a mouth wound occurs. Can what science is learning from fast healing mouth wounds even aid rotator cuff healing in the future? We will see.
It’s also interesting to note that gene expression can be altered by our environment. There is an actual field of study dedicated to this called epigenetics. Exercise, for example, has been shown to genetically alter aging. Even artificial devices placed in the body, such as a joint prosthesis, have been shown to affect our gene expression by creating genetic abnormalities due to wear particles from the devices. The genetic expression of our stem cells can also be altered by epigenetic influences, such as alcohol and steroid treatments.
The upshot? How your body uses its genes can make a big difference in how it heals. Can we, in the future, prime certain genes to instantly repair an injury? I suspect we’ll see more of this approach.