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DNA, SKIN AND AGING

GENETICS DETERMINE 60% OF OUR SKIN ASPECT AND PERCEIVED AGE

Recent investigations have identified genes involved in the aging process of the skin.

 

 

DNA AND SKIN

Related with the physical aspect, it has been learnt the influence of genetics in the skin aging process. Recent research studies have pointed out that genetics contribute 60% in our perceived age (i.e. how old or young do others see us, despite our real age).

Likewise, it has been found that around 1.500 genes are involved in the skin aging process. These genes are responsible for providing moisture, texture, elasticity, antioxidant capacity and sun protection to the skin, etc.

Knowledge of the human genome, genomics and proteomics are allowing designing more studies to identify areas in our genome where we are different from each other, the most frequent differences, and the regulatory mechanism thereof.

DNA sequences constituting the fundamental, physical and functional unit of heritage are called genes. Each gene contains a part that is transcribed into RNA and one that is responsible for defining when and where to express.

 

The information contained in genes (genetic) is used to generate RNA and proteins, which are the building blocks of cells, the “bricks” that are used for the construction of the cell organelles, among other functions, is the responsible of   regeneration, protection, skin structure process, etc. in the case of a GENOCOSMETIC view.

Genes express the proteins involved in most of the structure and skin process: collagen, elastin, catalases, collagenases, metalloproteinases, proteoglycans, etc.

As an example, we can mention the following genes that influence our skin and our appearance:

  1. One of the major factors in the aging process is hydration. The type of collagen that we produce, and consequently, the structure and appearance of our skin. There are variations in the genes that produce collagen, as well as enzymes that restructure this collagen (are called collagenases and metalloproteinases). Slight variations in these genes produce different types of collagen, for example, more interlaced and resistant collagen or a looser collagen. People with genes that express stronger collagen structures are predisposed to have fewer wrinkles than people with looser collagen.
  2. Resistance to oxidation and free radicals. Genetic variants that produce powerful antioxidant enzymes. These enzymes are called catalases and superoxide dismutases. For example,someone with a catalase gene encoding a potent catalase will be more resistant to free radicals oxidation attack.
  3. Different versions of the genes of aquaporins. Aquaporins are channels located in the cell wall, which regulate the cellular water level.  Consequently, variations in aquaporins have consequences in the skin hydration.  The existence of more or less powerful versions of these channels have been demonstrated, according to genetics.
  4. Genes involved in photoaging: Recently discovered gene variants have shown to offer the skin a greater resistance to aging by sunlight exposure. The mechanism by which this occurs is not well understood yet, but appears to be related with inflammation regulation. People with a certain gene variant are more resistant to ultraviolet rays coming from the sun, and therefore their skin is prone to age slower than others without these gene variant.

Variations in the gene nucleotides, SNPs or polymorphisms of a nucleotide (A, T, C, G), which are considered point mutations, i.e., they are simple changes in the DNA sequence, resulting in a variation of the functionality in the proteins. These variations can determine both the differences in our appearance (color skin, eyes and hair, height, etc.), as well as differences in metabolism and our internal functioning including the propensity of an individual to age in a certain way.  Determine which genes have SNPS with high population frequency; discriminating and dermatological impact is essential in genetic diagnostic evaluation of fundamental variables for the path of aging skin and our appearance.

Scientific researches have shown a correlation between genome, gene and protein expression in the aging skin.

Scientific researches have studied the comparison of gene expression in young skins compared with the gene expression in adult skins, as well as differences between intrinsic aging and photoaging of the skin. One of the main conclusions was that photoaging is a great accelerator of intrinsic skin aging.

Some scientists have hypothesized about Mosaicism. During the cell cycle, when DNA is copied from mother to daughter cells, there may be deletions, duplications and changes in DNA sequence, and a complete set of genes could be affected.  As a result different genetic profiles would exist in the same cell line.

Studies on Induced pluripotent stem cells (also known as iPS cells or iPSCs) demonstrate that IPS lines could act as a magnifying glass to see the mosaic of genomic differences in body cells.  "In the skin, this mosaic is extensive and at least 30 percent of the skin cells harboring a deletion or duplication of DNA," according to Dr. Vaccarino, Yale University School of Medicine, for whom this observation has reaching consequences in genetic analyzes.

NATURAL AGING

Life is a succession of changes, skin is proof of that. Our skin is at the mercy of all the forces acting on it: our genetic determination, the sun, weather and our own bad habits. But we can take steps to help our skin to stay supple and fresh. The Skin changes as you age.  You may notice more wrinkles, age spots and dryness. The skin also becomes thinner and loses fat, becoming less soft and smooth. When you age skin takes longer to heal. The skin changes are among the most visible signs of aging. Evidence of increasing age includes wrinkles and sagging skin.

As we age, the skin changes, it modifies, loses its natural moisture and deteriorates. The collagen, main support fiber of the skin, reduces its production.  As a result, the supporting tissue of the skin and the cohesion between the dermis and epidermis get weak, and the skin loses its tone and firmness.

Wrinkles are depressions on the skin surface, are visible signs of skin aging and which mainly appear on the face. There are two categories:

Expression lines, are those wrinkles related with gestures, are mostly located in the forehead, between the eyebrows and edges of the mouth.

Deep wrinkles:  are related to sagging skin, loss of tone and firmness. These changes cause alterations in the appearance of the face, mainly visible in the jaws and the appearance of double chin as well as the formation of bags under the eyes.

There are different mechanisms involved in the formation of wrinkles:

The action of the Muscles: The skin works constantly due to movements of the muscles that lie beneath. These micro-contractions help to the formation of lines because the skin continues into stress when it stretches and relaxes finally forming the wrinkle. 

Modification of the constituents of the dermis: intrinsic aging and aging caused by external factors, especially aging caused by the sun, causes changes in the cohesion between the dermis and the epidermis.

Modification of the skin: when time goes by the skin surface is altered. A decrease in natural moisturizing factors, in the activity of sebaceous glands or cell renewal, generates significant changes in the skin surface.

 

The main process of skin aging, oxidative stress damages cells of the epidermis and dermis and contributes to degeneration. Our genetics, DNA, environment, lifestyle and how we take care of our skin determine our skin aging route.  Knowing and acting in time are a tool to slow down the process and monitor their effects.