High-resolution molecular imaging to elucidate the mechanism of hearing loss due to connexin gene mutation

• Project/Area Number: 16591720
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: Kyoto Prefectural University of Medicine
• Principal Investigator: SUZUKI Toshihiro Kyoto Prefectural University of Medicine, Graduate School of Medicine, Associate Professor, 医学研究科, 講師 (20275225)
• Project Period (FY): 2004 – 2006
• Project Status: Completed (Fiscal Year 2006)
• Budget Amount: ¥2,000,000 (Direct Cost: ¥2,000,000); Fiscal Year 2006: ¥400,000 (Direct Cost: ¥400,000); Fiscal Year 2005: ¥400,000 (Direct Cost: ¥400,000); Fiscal Year 2004: ¥1,200,000 (Direct Cost: ¥1,200,000)
• Keywords: spiral limbus / connexins / gap junctions / glucose / GLUT / tight junctions / 6-NBDG

Research Abstract

To elucidate the role of the spiral limbus in glucose transport in the cochlea, we analyzed the expression and localization of GLUT1, connexin26, connexin30, and occludin in the spiral limbus of the rat cochlea. GLUT1 and occludin were detected in blood vessels. GLUT1, connexin26, connexin30, and occludin were also expressed in fibrocytes just basal to the supralimbal lining cells. Connexin26 and connexin30 were present among not only these GLUT1-positive fibrocytes but also GLUT1-negative fibrocytes. In vivo glucose imaging using 6-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-6- deoxyglucose (6-NBDG, MW 342) together with Evans Blue Albumin (EBA, MW 68,000) showed that 6-NBDG was rapidly distributed throughout the spiral limbus, whereas EBA was localized only in the vessels. Moreover, the gap junctional uncoupler heptanol inhibited the distribution of 6-NBDG. These findings suggest that gap junctions play an important role in glucose transport in the spiral limbus, i.e., that gap junctions mediate glucose transport from GLUT1-positive fibrocytes to GLUT1-negative fibrocytes in the spiral limbus.

Research Products

• [Journal Article] Gap junctions mediate glucose transport between GLUT1-positive and -negative cells in the spiral limbus of the rat cochlea. (2006)
  • Author(s): Matsunami T, Suzuki T, Hisa Y, Takata K, Takamatsu T, Oyamada M.
  • Journal Title: Cell Commun Adhes 13(1-2) Pages: 93-102
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Gap junctions mediate glucose transport between GLUT1- positive and-negative cells in the spiral limbus of the rat cochlea (2006)
  • Author(s): Tatsuya Matsunami, Toshihiro Suzuki, Yasuo Hisa, Kuniaki Takata, Tetsuro Takamatsu, Masahito Oyamada
  • Journal Title: Cell Commun Adhes 13(1-2) Pages: 93-102
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Gap junctions mediate glucose transport between GLUT1-positive and -negative cells in the spiral limbus of the rat cochlea.
  • Author(s): Matsunami T, Suzuki T, Hisa Y, Takata K, Takamatsu T, Oyamada M.
  • Journal Title: Cell Commun Adhes (In press)