Professor Do-Hyoung Kim and Professor Young-Joon Kim discover an insect control hormone

□ Professor Do-Hyoung Kim and Professor Young-Joon Kim of the School of Life Sciences at the Gwangju Institute of Science and Technology (GIST, President Seung Hyeon Moon) collaborated with Professor Michael E. Adams of UC Riverside (USA) to discover that the kinin ** hormone regulates the process of filling air in the respiratory tract during the process of molting * for insects.

* When an arthropod such as an insect molts its body during the growth process, the insect does not survive if there is a problem with the process.

** A peptide neurohormone, which is a short amino acid structure, plays an important role in epithelial action. This is the first time that a respiratory-related function is revealed.

∘ The insect's respiratory system is similar to the lungs of humans, and it functions to transport oxygen to tissues. When a baby is born, humans go through the process of discharging the secretions in the lungs. Insects, on the other hand, form new respiratory organs during the process of molting, and the process of getting air takes place.

□ The process of insect molting begins with the ecdysis-triggering hormone (ETH). * The brain responds to ETH by secreting a neurohormone called Kinin to absorb the fluids in the newly formed respiratory tract to regulate the air inflow. If there is a problem with Kinin, most insects will die from dyspnea because the fluids could not be absorbed.

* Ecdysis-triggering hormone (ETH) is a hormone that directly causes the last molting action. If this hormone is injected into an insect, it can cause the molting action even if a new layer is not ready.

∘ The research team used the Ca2+ imaging technology to demonstrate that Kinin, a hormone secreted from the brain, reaches the respiratory tract through the blood and activates respiratory tissue cells having the Kinin receptor. As the concentration of Kinin increased, respiratory tissues were activated more rapidly.

* A technique that measure changes in cellular activity in real time based on the concentration of intracellular calcium changes when the cell activity is elevated

□ The researchers also found that the sodium channel (ENaC: Epithelial Na channel) * plays an important role in the action of Kinin on the insect respiratory system. This channel works equally well in body fluids in human lungs. This finding suggests that Kinin has the potential to be used in the development of new medicines that solve the problem of lung edema and neonatal respiratory problems with symptoms of water in the lungs.

* Using the difference in sodium concentration inside and outside the lung tissue, the channels allow air exchange in the lungs through pressure changes

□ Professor Do-Hyoung Kim said, "This study was the first to show that insects can have respiratory illnesses similar in principle to humans and that the Kinin hormone play a key role in the process. It is expected that this will be used as a model for human respiratory research as well as new pest control using the asphyxiation phenomenon."

□ This study led by Professor Do-Hyoung Kim was carried out by Professor Young-Joon Kim (co-author) and Professor Michael E. Adams (correspondent author) and was supported by the Research Fellowship to Support Follow-up Generation Supported by Korea Research Foundation, GIST Research Fellowship, Creative Challenge Project of the Gwangju Institute of Science and Technology, and by the Korea Drosophila Resource Center (KDRC). The results of the research were published online on January 31, 2018, by PNAS (National Academy of Sciences), a global authority on natural science.