Scientists at Beiersdorf AG have made a new contribution to the understanding of skin: together with researchers of Charité University Medicine Berlin, they were able to demonstrate the existence of an inner clock in human skin cells, which controls skin regeneration among other things. Hamburg researchers from the team of Jörn Hendrik Reuter, PhD, head of the general skin care laboratory at Beiersdorf, and Professor Achim Kramer from the chronobiology department of Charité Berlin participated in the collaborative research project. “The findings from our collaborative research could have a large influence on the skin care of the future,” Reuter said.
In Beiersdorf’s test center in Hamburg, the circadian rhythms of the stress hormone cortisol present in the skin were studied in 20 test subjects. Furthermore, in the Berlin sleep lab, cell samples were taken from 20 volunteer subjects in four-hour intervals over the course of 24 hours. The analysis of these samples showed that about 10% of the genes in skin cells follow their own rhythm. According to the researchers, these most likely correspond to the respective chronotypes. The molecule “Krüppel-like-factor 9” (Klf9) stood out in the samples: “We observed that Klf9 is mostly active during the day. When it was inactive more rapid cell division was observed,” said Reuter. When the research team increased the concentration of Klf9 in the samples, cell division was significantly slower.
The results of the collaborative research project open up completely new possibilities for skin care. “The findings about the influence of Klf9 on cell division, for example, could be the impetus of the development of a new kind of anti-aging care. We could try to bring skin that is out of synch back into rhythm with its inner clock or perhaps we can address problems caused by lifestyle with skin care that targets chronobiology,” said Reuter.
The results may also be important for medicine. “With these findings the next step we might be able to take in research is finding out what the best time of day is for operating on someone so that their wound heals best. This is just one of the promising implications for medical research,” said Kramer.
Thomas Blatt, PhD, of Beiersdorf AG's R&D team and Professor Kramer’s team published the first results in the professional journal Proceedings of the Academy of Science in the paper Krüppel-like factor 9 is a circadian transcription factor in human epidermis that controls proliferation of keratinocytes.