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An activin A-producing osteoclastogenic fibroblast subset inducing bone destruction in cholesteatoma (M Ishii G, in Nat Commun.)


Cholesteatomas are made up of cysts or bumps in the ear that consist of skin, collagen fibers, skin cells, fibroblasts, keratin, and dead tissue. However, the exact mechanism for the creation of cholesteatomas remains unknown. The research group of Masaru Ishii (Graduate School of Medicine/Graduate School of Frontier Biosciences/IFReC) revealed the cause of cholesteatomas, which may help in developing new therapies for patients who are suffering from this disease. 

Fig. 1
Schematic of osteoclastogenesis induced by cholesteatoma fibroblasts expressing activin A.
IL-1β, PGE2, and TNF-α secreted from infiltrating CD45+ cells, particularly macrophages, induced activin A-expressing pathogenic fibroblasts; the activin A acted in conjunction with RANKL to promote ectopic osteoclastogenesis.


Prof. Masaru Ishii

Immunology and Cell Biology