They've been able to pinpoint a protein that's vital to keeping youthful-looking skin, but which diminishes with aging. This discovery was a major achievement in itself -- but it gets even better.
The researchers also identified two compounds that can stimulate the depleted protein to rejuvenate the skin.
They hope their work will eventually lead to an anti-aging skin cream. Keep reading for the full story. . .
Cells are in Competition
Over time cells suffer damage and develop some loss of tissue function. In short: they get old. We may not notice aging in our liver or kidneys, because we don’t see them, but we sure notice when it's the epidermis - the upper layer of skin.A hallmark of aging skin is a reduction in XV11 collagen (COL17A1 protein). This is a major component of hemidesmosomes -- tiny structures located on the inner surface of the epidermis. COL17A1 is critical for the stability of hemidesmosomes and so plays an essential role in strengthening and stabilizing the skin.
The work of Emi Nishimura, Professor of Stem Cell Biology at Tokyo Medical and Dental University, together with her colleagues, was based on the tail skins of mice. Sounds odd, but these happen to share many characteristics of human skin.
The researchers showed that not only does the number of hemidesmosomes diminish with aging but the loss correlates with low levels of COL17A1.
This depletion of the protein destabilizes other aspects of hemidesmosomes and eventually prevents their formation. COL17A1 was demonstrated to be the most unstable structure within hemidesmosomes in both mice and lab-cultured human epidermal cells.
Survival of the Fittest at the Cellular Level
Their work also showed that cells compete for space.COL17A1 encourages cell competition so that stressed and damaged (less fit) cells can be eliminated and replaced by new (fit) cells to keep tissue youthful. Cells that express high levels of COL17A1 out-compete and muscle out adjacent cells that express low levels of the protein.
But with many years of damage to epidermal stem cells, including damage from cellular stresses and UV radiation, COL17A1 eventually falls below a critical threshold.
Normal hemidesmosome formation becomes impaired, and there are fewer fit cells to compete with the less fit which are able to replicate. This leads to stem cell depletion, reduced ability to heal wounds, skin fragility, thinning skin, depigmentation -- and wrinkles.
Combats Aging
After the scientists had unraveled the mechanisms of skin aging, they next focused on what they could do to prevent it. Would it be possible to induce the expression of the COL17A1 protein to improve the ability of skin stem cells to regenerate the skin?The answer was yes.
They were able to identify two chemical compounds called Y27632 and apocynin. Both were tested with positive results.
In their research paper they wrote, "Application of these drugs to full-thickness skin wounds significantly promoted wound repair,” and they pointed to ways of “facilitating skin regeneration and reducing skin aging.”
In a commentary on the study in the journal Nature, Professors Ganna Bilousova and James DeGregori from the University of Colorado agreed that the research offered "proof of principle" that these compounds could indeed combat aging.
Professor Nishimura said it was her intention to collaborate with drug or cosmetic companies to create a product that can prevent skin deterioration and promote repair. They are also looking to see if their findings have application in other organs.
