Circadian rhythms are biological temporal patterns that oscillate in a 24-hour time cycle. Many physiological processes and behavioral variations are controlled by the rhythms, such as the daily sleep-waking cycle. The secretions of hormones and cytokines such as melatonin and interleukin-6 (IL-6) are also influenced by such cycles, which may influence the physiological responses and pathological reactions.
In addition to regular cells, stem cells are also regulated by the circadian clocks, especially those proliferating cells. Studies have shown that proliferating cell groups have their own circadian patterns (Hrushesky and Rich, 2015). The understanding of the impact of the circadian rhythms on stem cells would be helpful for finding novel therapies for various health problems and chronic diseases.
For example, in cancer therapy, the effects of the anti-cancer agents and treatment outcomes may be influenced by the administrative time of the drugs. Studies in the chronobiology of stem cells would be useful for the detection of the circadian patterns among hematopoietic stem cells (Hrushesky and Rich, 2015). The examination of such patterns would help improve the potential treatments based on stem cells.
Hrushesky W, Rich IN. Measuring stem cell circadian rhythm. Methods Mol Biol.
2015;1235:81-95. doi: 10.1007/978-1-4939-1785-3_8.