Circadian rhythm, which oscillate over a roughly 24-hour cycle in adaptation to the Earth's rotation, has been observed in most of the planet's plants, animals, fungi and cyanobacteria, and are responsible for regulating many aspects of organisms' physiological, behavioral and metabolic functions. Often referred to as the 'body clock', the circadian rhythm controls what time of day people are most alert, hungry, tired or physically primed due to a complex biological process. Scientists have now developed a novel way to harness the circadian clock and intend to use the method some day to deliver targeted drugs and cure jet lag.
The research team led by the Harvard synthetic biologist Pamela Silver have harnessed the circadian mechanism found in cyanobacteria to transplant the circadian wiring into a common species of bacteria that is naturally non-circadian. Silver said, "By looking at systems in nature as modular, we think like engineers to manipulate and use biological circuits in a predictable, programmable way." The team used this methodology to successfully transplant a circadian rhythm into the bacterial species E. coli.
Study's first author Anna Chen from Harvard Medical School said, "The ultimate dream application would be to deliver these circadian E. coli to an individual in pill form, which could allow the circadian rhythm to be linked to additional biological circuits in order to perform a precisely-timed release of drugs, or to be able to sense and influence the host's circadian rhythm."
The human circadian rhythm impacts metabolism, which when disturbed can contribute to obesity and glucose intolerance. Many drugs including those commonly used to treat cancers have been shown to fluctuate in their efficacy based on the time of day and the point in a patient's circadian cycle in which they are administered. Researchers hope that jet lag too might someday be combated using circadian E. coli that could be use to re-program and adjust the body's circadian rhythm to match the travel destination's day-night cycle.
The study is published in the Science Advances.