Why wounds heal more slowly with age

For years now, people have seen obvious evidence that supports the fact that older individuals do not heal as rapidly as younger individuals. Children have been known to be more resilient because of their hope, and young, strong body systems that are constantly overcoming obstacles and our elders are treated with delicate care and caution. Aging occasionally triggers various inheritable diseases or mutations that are caused by genetics. It has been a mystery as to what is causing the body to start slowing down the healing process as we age, so researchers at Rockefeller University began to explore the correlation between ages.

Healing wounds, whether superficial or extremely severe, is one of the bodies most complex processes because it involves various cell types, signaling systems, and molecular pathways that have to communicate and with time, close in and once again form its protective barrier. Immune cells and skin cells both work together to form a scab and keratinocytes act as a sheet and pile in beneath the wound.

Lab mice were used as the model organism for the experiment at the University. They were separated into two groups: 2 month-old mice and 24 month-old mice, which is the equivalent of having groups of 20 year-olds and 70 year-old humans. Researchers observed molecular changes in the mice's skin and it was found that the keratinocytes in the older mice moved much slower to their place below the scab, than those of the younger mice. This lack of speed in the keratinocytes resulted in the wounds taking days longer to heal in the older mice than the younger mice.

Researchers learned that after an injury, the keratinocytes communicate with specialized immune skills that reside in the skin. They produce proteins called Skints that are responsible for keeping the immune cells around, and together they help in filling in the gap of the wound. The scientists thought that they could boost Skint signaling in older individuals and speed up healing times. So they used a protein released by immune cells after an injury. Using petri dishes, scientists applied the protein with skin tissue samples from both young and old mice to discover that they had enhanced keratinocytes' migration, and the older keratinocytes more closely resembled those of the younger mice.
This study provides hope for the future in terms of speeding up the healing process for older individuals. It is only normal for healing speeds to begin to lag after a certain age, but if scientists are able to produce a drug that would be capable of counteracting that, like they think is possible, it would minimize people's pain and discomfort greatly, as well as increase health.

https://www.sciencedaily.com/releases/2016/11/161117151059.htm