The Key to Youthful Skin is Skin Remodeling
Vigorous skin renewal and skin remodeling is the key to maintaining a youthful skin. Children have wonderful skin with a high natural self regeneration and a beautiful color and texture. When a child's skin is damaged, the wounds heal rapidly and scars and skin lesions are quickly removed.
Reducing damage to your skin is not an adequate approach. You can hide from sunlight until you evolve into a mole but this will not keep your skin young and vibrant. Yes, avoiding UV light will reduce some types of skin damage as you age, but you will still end up with a pasty, grayish, lifeless, pale skin. Avoiding skin damage from ultraviolet light, allergens, detergents, damaging soaps, irritants, acne scars, airborne pollutants, chemical sunscreens and so forth is but only one part of a wider story.
As we age, a number of skin changes occur which require different types of skin care and treatments. These are four basic changes as we age.
Change 1. The rate of skin cell replacement is reduced, producing a thinner, more fragile skin. Skin is replaced every three weeks at age 20 but this increases to every nine weeks by age 50.
Change 2. Damaged protein accumulates in the skin. This damage can be the results of scars, sun damage, oxidative damage, and the cross-linking of skin proteins by sugars.
Change 3. After age 25, skin oil production starts to drop. This reduces acne but produces a dryer skin. This drop in oil production becomes more serious after age 45.
Change 4. The biosynthesis and breakdown of collagen, elastin, and the water-holding proteoglycans and GAGs exists in a dynamic balance in young healthy skin. However after age 25, the skin's production of collagen, elastin, the water-holding molecules is reduced while the breakdown of these factors is increased. This begins wrinkle formation and loss of elasticity. The problem become progressively more serious with passing years.
To understand skin renewal and remodeling, it is necessary to understand skin repair. The sequence of events producing skin renewal is very similar to the mechanisms involved in wound healing. The human body uses the same biochemical systems in many different ways.
1. Initially after skin damage or wounding, the body's damage control mechanisms serve to stop blood loss (if any), then to quickly cover the damaged skin with a layer of tough and protective scar tissue. A type of immune cell, called the neutrophil, quickly arrives in the damaged area. The neutrophils sterilize the damaged area by releasing very toxic oxygen radicals to kill bacteria. This neutrophil action is usually very brief and usually stops within a day. However, occasionally the damage is of a type that continues these neutrophil actions and the skin becomes chronically inflamed.
Also, a scar forming hormone called TGF-beta (transforming growth factor beta) is produced to stimulate scar production. Large amounts of scar-forming collagen are secreted into the damaged area. Many cosmetic companies have recently began selling skin creams with peptides said to have actions similar to TGF-beta. Such peptides were extensively tested for wound healing about 10 years ago but produced excessive skin hardening and scarring.
2. The tissue damage also causes the release of enzymes which, in turn, break down skin proteins into smaller fragments. Copper ions begin to accumulate within a few days and are complexed with peptides in the damaged area. If copper is deficient, then healing will be inadequate. No other metal ions are concentrated. The copper-peptides serve as chemical signals to the immune system that the skin is injured and needs repair.
3. The copper peptides then initiate the phase of healing called skin remodeling. In this phase, the scar tissue is removed and replaced with normal skin tissue.
4. As copper peptides accumulate, they act directly to
protect the tissues by (1) stopping the production of, and sterilizing effects
of, oxygen radicals and (2) suppressing scar formation by inhibiting the
production of TGF-beta.
5. The copper peptides also attract a type of immune cell called a macrophage which arrives after the neutrophils have sterilized the tissue. The macrophage begins to ingest the skin debris produced by the damage and also secrete about 20 different growth factors needed for proper skin repair. These have names such as epidermal growth factor, fibroblast growth factor, platelet-derived growth factor and so on. Regranex Gel sold by McNeil Pharmaceutical and used for wound healing contains a macrophage-released growth factor, called platelet-derived growth factor. The macrophage action also helps remove chronically-damaged, abnormal skin such as spots and lesions from sun damage.
6. The copper peptides also stimulate the production of the scar removal systems by changing the synthesis of metalloproteinases (a family of at least 14 proteins that remove damaged proteins such as damaged collagen and elastin) and antiproteases. At the same time, the copper peptides stimulate the production of new proteins such as collagen and elastin to give the skin strength and elasticity, and other proteins and molecules such as proteoglycans and glycosaminoglycans (GAGs) that bind large amounts of water to moisturize the skin. The only true skin moisturization is via these water-holding molecules. The copper peptides also stimulate angiogenesis (new capillary formation) to reestablish new blood vessels to nourish and oxygenate the newly repaired skin.
7. Skin remodeling continues for a long period. The wounded area slowly improves as scar tissue is removed or reduced. Incomplete healing causes heavy scarring but complete healing produces minimal scarring. The old damaged protein is removed and replaced with new collagen and elastin fibers. This removes scar tissue and restores skin elasticity. This mechanism can also be used to reduce wrinkles.
8. Skin renewal and hair follicles are closely linked. New skin is now thought to arise from the hair follicles. All skin remodeling chemicals or genes that activate skin remodeling also increase hair follicle size. But skin although skin remodeling improves hair follicle health, it not create new follicles or grow hair in hairless areas.
|
Skin Remodeling Chemicals or
Methods |
|||||
|
Product
or Method |
Causes
skin remodeling |
Present
in wounds and human blood |
Anti-inflammatory |
Increases
hair follicle size |
Reduces
TGF-beta and scar production |
|
Retinoic
acid (Retin-A) |
Yes |
Not
significant |
No,
causes redness and irritation |
Yes |
No,
increases TGF-beta production |
|
First
Generation |
Yes, |
Yes,
this is the human body's natural remodeling signal |
Yes,
potent anti-inflammatory, Blocks actions of of Interleukin-1, a skin damaging cytokine |
Yes |
Yes,
reduces TGF-beta |
|
Second
Generation - |
Yes, similar to GHK-Copper but not as well studied Better than GHK-Copper in skin repair models |
Yes |
Yes,
potent anti-inflammatory, |
Yes |
Reduces
scaring but |
|
Increase
HEDGEHOG or Wnt Genes in mice, increase production
of beta-catenin |
Yes |
Not
applicable |
Unknown |
Yes |
Unknown |
Written by Dr Loren Pickart