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EDUCATION
IMPAIRED ENZYME ACTIVITY NOT “DEHYDRATION” By Kai Atkinson, derma aesthetics Educator
The word “dehydration” is vastly overused within the aesthetics and beauty industry, along with the condition misdiagnosed and at times, treated incorrectly. Why is this? Well, it comes down to understanding the cells and systems involved as to why there is a lack of free water within the epidermis and being able to recognise the link between fast trans-epidermal water loss (TEWL) and an impaired acid mantle. In order to discuss the lack of free water within the epidermis and how this relates to “impaired enzyme activity,” we first need to understand the role of the circulatory and lymphatic system. These two systems that contribute to immunity are so vitally important when it comes to maintaining balanced hydration and tissue homeostasis, and when compromised, can have serious consequences on the cellular hydration levels of the skin.
The Circulatory & Lymphatic System The circulatory system is a continuous endothelial tissue network that contains specialised cells called haemoglobin. These red blood cells are attracted to the oxygen-rich molecules that we breathe in through our lungs, and in doing so, will support the transfer of these oxygen molecules throughout the body in order to bring fresh oxygen to all tissues, including the cell producing layers of the skin. The circulatory system contains plasma, and this fluid makes up a very large portion of your blood as it is responsible for transporting oxygen, nutrients, hormones, proteins, enzymes, cytokines and growth factors to where they need to go. These metabolic substances play a vital role in supporting sufficient water levels within the skin.
loss (TEWL), and is a normal metabolic process that is required for sustaining tissue homeostasis. The lymphatic system is a complex system that works in unison with the circulatory system. It is responsible for transporting fluids, fats and fat soluble vitamins, dendritic cells and infectionfighting white blood cells throughout the body in order to maintain immunity for host defence. The lymphatic system is also responsible for the removal of metabolic waste that accumulates as cells undergo mitosis, proliferation, differentiation and apoptosis. The lymphatic system is not continuous, unlike the circulatory system, and for a simple analogy, can be thought of as being a fitted glove on the hand. The glove contains specialised compartments for your fingers, but once your fingers are embedded in the glove, there is nowhere else for them to go. In other words, the lymphatic vessels contain dead end capillaries that rely on the circulatory system to help transport the movement of substances through the action of sympathetic movement. This, in turn, supports cellular hydration levels by keeping all fluids in the body constant and in homeostasis. The lymphatic system together with the circulatory system are invaluable to the health and wellbeing of the body and of course, skin. By supporting these two systems, cellular hydration within the epidermis and dermis will be supported. Let’s now take a look at the “Epidermal Barrier” and how the keratinocyte in particular, plays a major role in sustaining the water levels within the skin.
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Beauty Biz Year 14 Issue 4
Acid mantle/microbiome Is a complex mixture derived entirely from sebaceous gland secretions, eccrine sweat and the multi-lamellar lipid structure. Stratum corneum The end result of the keratinocytes life cycle and is a hydrophobic cell. Natural moisturising factor (NMF) Formed by the enzymatic breakdown of profillagrin and is vital for stratum corneum hydration. Multi-lamellar lipid structure Composed of ceramides, cholesterol and free fatty acids and is responsible for the permeability barrier function of the epidermis. Let’s now have an overview the life cycle of the keratinocyte and how its built-in defence mechanisms contribute to the barrier function of the skin, in order to maintain adequate cellular hydration levels.
In relation to the circulatory system, the hyaluronic acid (HA) component of the glycosaminoglycans (GAG’s) plays a very important role in contributing to balanced hydration levels and tissue homeostasis. The HA brings in the plasma from the circulatory system down into the extracellular matrix of the dermis, where it facilitates the creation of the dermal reserve. The dermal reserve contributes to cellular protection and hydration as it supports the facilitation and recruitment of immune cells, enzymes, proteins, hormones and nutrients. Part of the dermal reserve (also known as the “extracellular fluid”), will make its way through the perforated connective tissue of the dermal/ epidermal junction (DEJ) in order to nourish the cells and systems of the epidermis, as it contains the oxygen, nutrients, hormones, proteins, enzymes, cytokines and growth factors this tissue requires to function correctly. This water movement is known as trans-epidermal water
leading role in supporting the water retention power of the epidermis, as it creates important lines of skin barrier defence. These defence systems compromise of the following:
As keratinocytes of the epidermis migrate from the spinosum layer into the granular layer, a lot of cellular activity takes place. The cornified cell envelope (CCE) via enzymatic activity begins formation along the interior of the keratinocytes plasma membrane. This phospholipid membrane will eventually be enriched by a lipid envelope known as the “multi-lamellar lipid structure” primarily composed of ceramides, cholesterol and free fatty acids, that will covalently attach itself to the exterior of the CCE.
The Epidermal Barrier When we use the terminology “epidermal barrier,” as an industry, we are almost always referring to the stratum corneum and its ability to maintain and regulate TEWL. The keratinocyte plays a
Once in the stratum corneum, the CCE contains anchoring protein structures called corneodesmosomes that anchor into the corneocyte. This, in turn, supports cell barrier alignment to ensure a densely compacted and well structured stratum corneum. By having a compacted and well formed stratum corneum,
