Bronchial asthma is a disease that causes chronic inflammation of the respiratory tract triggered by allergens and infections, causing paroxysmal coughing and dyspnea, and it is said that there are more than 3 million patients worldwide. ..While inhaled steroids, which reduce airway inflammation, have made it possible to control most bronchial asthma, if the symptoms are severe, the steroid dose should be increased by oral administration or instillation, which includes infections and hypertension. There are risks such as.Recently, molecular-targeted drugs with few side effects have been developed, but not all patients have therapeutic effects.

　The mechanism of onset of bronchial asthma has been extensively studied, and it has become clear that a protein called interleukin 33 (IL-33) plays an important role.However, there were many unclear points regarding the mechanism for controlling the amount of IL-33.

　The research group, which was conducting research on the physiological function of Mex-3B, an RNA-binding protein, conducted an analysis using a mouse model of bronchial asthma.As a result, it was clarified that Mex-3B promotes the expression of IL-33 and spreads airway inflammation.Analysis of its regulatory mechanism also revealed that Mex-3B increases the amount of IL-33 protein by directly binding to IL-33 mRNA and inhibiting the function of small RNAs called miRNAs.

　Furthermore, it was discovered that airway inflammation can be suppressed by suppressing the action of Mex-3B in the airways by spraying and inhaling antisense nucleic acid (which binds to the target RNA and promotes its degradation) against Mex-3B.

　The results of this study suggest that a drug targeting Mex-3B may be a new therapeutic agent for bronchial asthma. Mice lacking the Mex-3B gene have normal development and no abnormalities are observed even in adults, so it is expected that they can be a therapeutic drug with few side effects.