Brown-Kurume Exchange Programs Have Developed Through Many Unexpected Encounters and Relationships.

In July 1992, my 24 years of studying abroad in the US as a researcher at Harvard Medical School started. During this period, I met many outstanding scholars who conducted some of the world's leading research projects. In particular, the opportunity to collaborate with Dr. Jack A. Elias, Professor and Dean Emeritus of the Faculty of Medicine at Brown University, on a project focusing on a molecule called Chitinase 3-like 1 was very helpful to my career, and eventually led to my current position as Professor in charge of international medical exchange at Kurume University School of Medicine. By strengthening the foundation of our exchange programs and actively promoting international joint research projects, I would like to raise the global name recognition of Kurume University.

Recently Updated Role of Chitinase 3-like 1 on Various Cell Types as a Major Influencer of Chronic Inflammation.

Chitinase 3-like 1 (also known as CHI3L1 or YKL-40) is a mammalian chitinase that has no enzymatic activity, but has the ability to bind to chitin, the polymer of N-acetylglucosamine (GlcNAc). Chitin is a component of fungi, crustaceans, arthropods including insects and mites, and parasites, but it is completely absent from mammals, including humans and mice. In general, chitin-containing organisms produce mammalian chitinases, such as CHI3L1, to protect the body from exogenous pathogens as well as hostile environments, and it was thought that it had a similar effect in mammals. However, recent studies have revealed that CHI3L1 plays a pathophysiological role by inducing anti-apoptotic activity in epithelial cells and macrophages. Under chronic inflammatory conditions such as inflammatory bowel disease and chronic obstructive pulmonary disease, many groups already confirmed that the expression of CHI3L1 is significantly induced on the apical side of epithelial cells, and activates many downstream pathways involved in inflammation and carcinogenesis. In this review article, we summarize the expression of CHI3L1 under chronic inflammatory conditions in various disorders and discuss the potential roles of CHI3L1 in those disorders on various cell types.