Cell to Cell Communication

A cell is the smallest unit of life that makes up all living things. Cells are the building blocks of the body that carry out specific functions. They heal, repair, and reconstruct the body. We have approximately 200 different types of cells and 30 to 40 trillion cells in the body. Cells communicate to regulate cellular functions and maintain homeostasis throughout the body. Homeostasis provides a stable environment despite external changes including temperature, bacteria invasion, sun exposure, diet, and the natural aging process.

Communication is an important aspect when it comes to all relationships. The same goes for the relationship between cells in the human body. Without proper communication, body systems may not function properly. Communication between cells works by a signal molecule, called a ligand, binding with a receptor. A receptor is a molecule in which a ligand can attach to carry out an action. It is similar to a lock and key; the ligand would be the key and the receptor would be the lock. Cells are constantly sending and receiving messages, not only chemical messages but mechanical and electrical as well. An example of mechanical signaling is in the case of muscle growth with exercise. Regulating heartbeat is an example of an electrical signal. The body is like one big communication network.

Think of cellular communication like the game telephone, where one person sends a message through a chain of people and the last one conveys the message they heard. If you’ve ever played the game, you would notice that communication isn’t always clear, and the wrong message is often delivered. The same can happen with signaling between cells. Body systems aren’t always functioning at their optimal level due to age, illness, and/or external factors. This can cause mixed signals, over-communication, or under-communication. For example, when keratinocytes aren’t healthy, they may send signals to the melanocytes to produce pigment even if there is no initial threat.

Receptors can be on the inside of the cell called intracellular or on the outside of the cell making it extracellular, depending on its solubility.  For instance, peptide hormones can’t enter the cell since they are water-soluble, therefore the receptors for these hormones are on the outside of the cell. Molecules that are hydrophobic or lipid-soluble can easily penetrate the cell membrane, therefore the receptors are on the inside of the cell. An example of this would be steroid hormones.

There are three steps to cell signaling. First is the reception, this is where the ligand (key) fits into the receptor (lock). The second step is transduction, the binding of the ligand and receptor activates intracellular molecules and triggers a change inside the cell. The final step is the response which produces the desired outcome. The outcome can be to influence one or more cellular processes including cell division, pigment production, collagen production, wound healing, and to fight off infection.

Communication is vital to all bodily functions including those of the skin. Cell signaling helps the body maintain its pH, temperature, and energy levels which are essential to survival. The healthier we are the better chance we have that the necessary signals are communicating as they should. The same goes for the skin, feeding it with nutrients and protecting it from external elements like excess sun exposure and pollution will promote its health and essentially its appearance. Taking care of the body by supplying it with necessary vitamins and nutrients from food or other sources will help keep the cells communicating in a healthy state.