Our Body Clocks Cause Wounds Sustained at Night to Heal More Slowly
Source: Medical Research Council – UK
Summary: Researchers have found that wounds sustained at night heal twice as slowly those sustained during the day which has implications for surgery and wound-healing medicines.
Every cell in the human body is regulated by the body clocks or circadian rhythms which drives many processes such as sleeping, hormone secretion and metabolism. Tests using skin cells – fibroblasts and keratinocytes in mice showed ‘daytime’ wounds to the skin healed nearly twice as efficiently as wounds incurred during the night. Researchers from the Medical Research Council (MRC) Laboratory of Molecular Biology in Cambridge, UK in a new study found that how our body clock’s are responsible to heal the wounds such as cuts and burns 60% faster if the injury happens during the day rather than at night. The study was published in the journal Science Translational Medicine.
Researchers have analyzed records of 118 patients with burn injuries. What they observed was, burns that happened at night (8 pm – 8 am) took an average of 28 days to get healed and the burns that happened during the day (8 am – 8 pm) took just 17 days. They noted the key reason for this faster healing was that skin cells moved faster to the site of a wound to repair it during the body clock’s daytime. This was driven by the increased activity of a protein called actin. Filaments of actin provide scaffolding and movement, acting like a muscle inside the cell. And also, in daytime wounds more collagen is deposited at the wound site. Finally, the researchers note that this whole process is driven by internal circadian clocks but not signals transmitted throughout the body. This study could have implications for surgeries and wound-healing medicines.
Dr. John Blaikley, an author on the study said, “Treatment of wounds costs the NHS around 5 billion a year, which is partly due to a lack of effective therapies targeting wound closure. This research, for the first time, shows how circadian factors are important for wound healing. By taking these into account, not only could novel drug targets be identified, but also the effeciveness of established therapies might be increased through changing what time of day they are given.”
More Information: N.P. Hoyle et al, “Circadian actin dynamics drive rhythmic fibroblast mobilization during wound healing,” Science Translational Medicine (2017).