The role of Musashi1in the development and regeneration of vertebrate Inner ear

2004 Fiscal Year Final Research Report Summary

• Project/Area Number: 15591814
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: Osaka University
• Principal Investigator: MURATA Junko Osaka University, Graduate School of Medicine, Assistant Professor, 医学系研究科, 助手 (80332740)
• Co-Investigator(Kenkyū-buntansha): OKANO Hideyuki Keio University, Graduate School of Medicine, Professor, 医学部, 教授 (60160694) ; KUBO Takeshi Osaka University, Graduate School of Medicine, Professor, 医学系研究科, 教授 (30107031)
• Project Period (FY): 2003 – 2004
• Keywords: Musashi1 / sensory epithelium of inner ear / regeneration / Notch signaling pathway / hair cell / supporting cell / Math1 / activated Notch1

Research Abstract

We have been investigated the expression pattern of Musashi1, one of typical neural stem cell markers in mouse inner ear. In the inner ear of young adult mice, Musashi1 immuno-positive cells were observed in vestibular and cochlear ganglion cells and supporting cells within the sensonsory epithelium. The results were published in Neuroscience letters 354 (2004), 201-204. Prof.Okano, one of our co-investigators, showed that Musashi1 activates Notch through blocking the function of Numb. Notch signaling pathway has been thought to play a crucial role in vertebrate inner ear development. Indeed, the expression pattern of Notch-related genes and the result of function-loss experiments using Jagged2-deficient mice, indicated that lateral induction, one of famous role of Notch signaling pathway, functions in the formation of a fine mosaic pattern of hair cells and supporting cells in the sensory epithelium. Thus to clarify the role of Musashi1 in the development and regeneration of inner ear, we thought that it is important to investigate the spatio-temporal expression pattern of Notch activation in vertebrate inner ear. We used a specific antibody that recognizes the processed form of the intracellular domain of Notch1 cleaved by presenilin/gamma-secretase activity. We indicated that Notch1 was transiently activated exclusively in supporting cell lineage and the activated form of Notch1 was not found at all in math1 positive hair cell precursors. These results were presented at 2005 ARO Midwinter Research Meeting (February 19-24, New Orleans, U.S.A.).

Research Products

• [Journal Article] Expression of Musashi1, a neural RNA-binding protein, in the cochlea of young adult mice (2004)
  • Author(s): Murata, J., Murayama, A., Horii, A., Doi, K., Harada, T., Okano, H., Kubo, T.
  • Journal Title: Neuroscience letters 354 Pages: 201-204
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Expression of Musashi1, a neural RNA-binding protein, in the cochlea of young adult mice (2004)
  • Author(s): Murata, J., Murayama, A., Horii, A., Doi, K., Harada, T., Okano, H., Kubo T.
  • Journal Title: Neuroscience letters 354 Pages: 201-204
  • Description: 「研究成果報告書概要(欧文)」より