(image: KobIz Media / Korea Bizwire)
DAEJEON, Nov. 10 (Korea Bizwire) — A research team consisting of local and international staff has mathematically identified the reason why obesity causes sleep disorder.
A joint research team set up by the Korea Advanced Institute of Science and Technology (KAIST) and the Florida State University announced on Monday that they had identified the principle of how the cytoplasmic congestion caused by obesity disturbs the biorhythm.
Human bodies automatically adjust body temperature, blood pressure and sleep schedule by secreting hormones in accordance with the biological clock ‘circadian rhythm.’
The PER protein within the brain plays the role of controlling the circadian rhythm. It changes at an interval of 24 hours.
The amount of the PER protein increases for 12 hours and then decreases for the remaining 12 hours. This pattern occurs at an interval of 24 hours.
The principle is that the PER protein accumulated in the protoplasm for 12 hours enter at once into the nucleus, hindering the transcription of PER genes thereby reducing the amount of PER.
However, it was uncertain how tens of hundreds of PER proteins can enter at once into the nucleus in a cell environment where a variety of materials co-exist. Thus far, it has remained as unsolved mystery for the academic community.
The research team solved the mystery by developing a spatiotemporal and probabilistic model that describes the movement of PER in a cell environment.
Phosphorylation is needed for PER to enter into the nucleus. To make this happen, PER proteins should be sufficiently clustered around the cell.
However, if cytoplasmic congestion is caused by obesity, it hinders the movement of PER proteins. As a result, PER proteins enter into the nucleus at an irregular time, making the circadian rhythm unstable.
“Our study showed that diseases like obesity, dementia and aging that cause cytoplasmic congestion can make the sleep cycle unstable.” said Kim Jae-kyoung, a professor at KAIST.
Kevin Lee (kevinlee@koreabizwire.com)
