What controls how stem cells behave in the body? While we know that the cells detect what’s around them and respond, are there other things that tell them what to do? Turns out that the nervous system plays a role as well. Let’s dig into that topic.
Understanding Stem Cell Proliferation
Proliferation means growth and division. Therefore, the process of cell proliferation involves the cells getting larger and increasing in numbers. This is one way that dead or dying cells in your body are replaced.
Stem cells are also the body’s natural around-the-clock repairmen, those healing cells that coordinate repair throughout the body. Somatic stem cells are adult stem cells (as opposed to embryonic stem cells). Our adult stem cells proliferate, or grow and divide, with each stem cell creating two copies of itself (a progenitor cell and one cell that’s kept in reserve). The new progenitor cell then begins the process of regenerating or healing our damaged tissues by specializing into the local cell needed and replacing a dying cell (another step in the process, known as cell differentiation). These cells also work by coordinating the local repair response, sort of like a building contractor.
Learn more by watching my video on stem cell differentiation below:
What Is the Autonomic Nervous System?
The hypothalamus in the brain is the control center for the autonomic nervous system (ANS). The autonomic nervous system is responsible for mostly involuntary functions, such as heart and respiratory rate, blood flow, digestion, reflex responses (sneezing, swallowing, etc.), It actually consists of three systems in one. The sympathetic nervous system is sometimes referred to as a fight-or-flight system. The parasympathetic nervous system is sometimes referred to as the rest-and-digest system. The enteric nervous system is the gastrointestinal nervous system and is associated with regulating digestion.
Now, a new study suggests that the ANS plays an active role in another involuntary function: stem cell proliferation. Let’s review.
Study Suggests the ANS Controls Stem Cell Proliferation
Working under the suspicion that the autonomic nervous system was involved in stem cell proliferation, researchers conducted a new study to determine if the involvement was a direct or indirect one.
The results? Studying stem cells in the lining of the intestines in mice, they discovered receptors on these cells for the ANS neurotransmitters. This means the ANS neurotransmitters can directly bind to the stem cell receptor and activate and even alter the behavior of that cell. They also found that exposing the stem cells to two common ANS neurotransmitters (i.e., norepinephrine, acetylcholine) resulted in a decrease in proliferation of the cells, further confirming the ANS had a direct effect on stem cells but also demonstrating that when the body is in fight-or-flight or active digestion mode, it keeps its energy resources focused on these critical functions rather than on creating new cells. So in short, the researchers concluded that the ANS not only plays a part in stem cell proliferation but actually directly controls it, increasing and limiting proliferation as the body demands.
Researchers believe that by finding a direct link between the ANS and stem cell proliferation, this can lead to ways to manipulate the ANS to either stimulate more cell growth and division when needed or even to limit growth and division when needed. Why would they want to limit it? Tumors are the result of an overgrowth of cells, so finding a way to limit growth may lead to advances in cancer prevention and treatment. On the other hand, being able to increase cell growth and division via the ANS could lead to advances in tissue healing and regeneration.
The upshot? It’s pretty cool that your body can control your stem cells through the autonomic nervous system. This will open up a whole new field in stem cell control that could one day be used in interesting ways to fight disease.