Current study wound healing influenced by the day

Our internal clock affects wound healing

If people suffer from a skin injury, it could make a difference to the cure at what time of the day the wound occurred. British experts have now discovered that the production of actin and the mobility of fibroblasts changes rhythmically throughout the day. The internal clock influences the biological activity. In other words, the duration of a healing process is also determined by what time of the day the wound occurred.

Researchers at the University of Manchester and Cambridge Medical Research Council found that skin healing affects the healing process by the time the wound was formed. The physicians published the results of their study in the journal "Science Translational Medicine".

The time of wound healing is influenced by what time of the day the wound has come. Our internal clock thus has an effect on the healing of injuries. (Image: gamjai / fotolia.com)

Biological activity of connective tissue cells changes throughout the day

The time of day determines how quickly skin injuries heal. Depending on the time of day, a skin wound can heal up to twice faster, influenced by the production of actin and the mobility of fibroblasts. Fibroblasts are so-called mobile connective tissue cells. They play an important role when it comes to healing skin injuries. However, the biological activity of connective tissue cells changes during the day, the researchers say.

If the wound healing in the future significantly improved?

The scientists discovered in their study that fibroblasts from mice produce more actin during the waking phase of the animals compared to the resting phase. Actin is a protein that allows the cells to migrate into the injured tissue, the experts explain. It also affects the formation of solid cell contacts. Based on the current study results, the wound healing of patients after surgery could be significantly improved in the future.

The evolution led to improved wound healing during the day?

The internal clock in every single skin cell influences how effectively the cells respond to the onset of injury, explains author John O'Neill of the Cambridge Medical Research Council. Human evolution could have caused existing injuries to heal faster during the day than at night. This could be because the risk of injury during the day is greater, the expert adds.

Effects of the heart clock

An internal clock is ticking in all cells in the human body. Such watches are synchronized by special brain cells. As a result, the wake-sleep rhythm adapts to the natural day-night change. In addition, every organ of the body develops its own so-called circadian rhythm of its function, explain the experts. Such daily rhythms are influenced by specific genes whose activity changes during the day. The activity increases and decreases regularly within 24 hours. This also affects the levels of proteins encoded by these genes. The resulting fluctuations also affect other metabolites, add the scientists.

Experts studied 1608 proteins

With the help of cell cultures, the British researchers investigated which proteins in the fibroblasts of mice are produced on a daily basis. The physicians examined a total of 1608 identified proteins. In 237 of the examined proteins a so-called circadian rhythm could be detected. Several of these proteins are involved in the formation of the cytoskeleton. This consists of filamentous molecular assemblies, which give the cell its strength and mobility. A major part of this cell structure is actin. During the waking phase of mice (at night), the fibroblasts produced more actin than during the day. This established rhythm was retained in the so-called cell culture. Therefore, it can not be controlled by other factors of the living animal.

Phase of increased production of actin accelerates wound healing

Changes that could affect the efficiency of wound healing during the day were analyzed by the experts using three different methods. They examined cultures with locally destroyed cell layer. In addition, cultures of skin tissue were examined in which previously punched holes, and finally, there was also an investigation, which was carried out on living mice with an existing cut injury, explain the authors. In all studies, the same result was found, in the phase of increased production of actin accelerated wound healing.

Night-time burns take longer to heal

The researchers examined the relationship found by analyzing the medical data of a total of 118 patients with burns. It was found that burns caused at night require a longer time to heal. Such a cure of burning took on average 60 percent more time than if this connection had been made during the day, explain the doctors.

Further research is needed

If the wounds had occurred at night, a 95 percent cure took 28 days. On the other hand, if the wounds had occurred during the day, the cure lasted only 17 days. The fastest possible healing of wounds is clinically relevant because faster healing reduces the risk of infection and chronic wound healing disorders. By further investigations of the effects of the internal clock on the wound healing, active substances could be developed in the future, which can significantly improve the healing success. (As)