The visible signs of skin aging are reflected by a similar loss of elasticity and function in important tissues inside the body, driven by declining function in stem cells that support these tissues, a steep growth in the number of senescent cells that hamper maintenance of tissue integrity, the accumulation of AGEs - largely glucosepane - and the other mechanisms that cause aging.
These root causes must be dealt with, but comparatively few scientists are trying to tackle them directly. The more usual research focuses on ways to try to patch over consequences by making use of other mechanisms - somewhat akin to trying to deal with a broken dam by bailing rather than fixing the holes. Here researchers manage to reverse a fraction of the effects of skin aging:
[The] extracellular matrix, or ECM, acts like the scaffold that skin cells roost in. It's made of tiny fibrils of collagen, produced by the cells (fibroblasts). Over time, as skin ages, the ECM becomes fragmented, which causes cells to lose their connections to that scaffold - and the lack of support accelerates their decline further. The same thing may happen in other types of tissue.
[Scientists] injected the skin of 21 volunteers in their 80s with a filler often used cosmetically to reduce facial wrinkles. The filler bolsters the ECM, filling in the spaces left by aging. The researchers did not receive funding from the product's manufacturer, nor did they get input on the design or results from the company. Rather, they were using the product as a way to increase the mechanical forces within the volunteers' skin. The result: over three months, the fibroblasts began expressing collagen-related genes, producing more collagen, and connecting better to the ECM. The entire layer of skin grew thicker, and more blood vessels, which nourished the cells were seen.
"Fragmentation of the extracellular matrix plays an important role in skin aging, but by altering the matrix using an external filler and increasing the internal pressure, we've shown that we can essentially trigger a signal for cells to wake up. This shows that skin cells in elderly people have the capacity to respond robustly in a very positive way to alterations in the mechanical property of their environment. We still need to know more about how cells sense their environment, but in general it appears we have made a real difference in the structural integrity of skin."