Unique expression of connexins in the human cochlea

详细信息    查看全文

• 作者：Wei Liu ; Marja Boströ ; m ; Anders Kinnefors ; Helge Rask-Andersen
• 关键词：Human cochlea ; Connexin ; Gap junction channel ; Immunohistochemistry ; Human spiral ganglion ; Speech signal processing
• 刊名：Hearing Research
• 出版年：2009
• 出版时间：April 2009
• 年：2009
• 卷：250
• 期：1-2
• 页码：55-62
• 全文大小：626 K

文摘

Mutations in the genes GJB2 and GJB6, which encode the proteins Connexin 26 (Cx26) and Connexin 30 (Cx30), have been linked to nonsyndromic prelingual deafness in humans. These proteins may form so-called gap junctions (GJ) or transcellular pathways between cells. The pathogenesis of deafness due to GJ Connexin mutations remains unclear partly because examinations performed in the human ear are infrequent. Here we analysed the expression and distribution of Cx26 and Cx30 in five fresh normal human cochleae taken out at occasional surgery. Immunohistochemistry including confocal microscopy in decalcified specimen showed that these proteins are widely expressed in the human cochlea. In the lateral wall there was strong antibody co-labeling for Cx26 and Cx30 that support the existence of channels comprising heteromeric Cx26/Cx30 connexons. In the organ of Corti there were some co-labeling in the supporting cell area including mainly the Claudius cells and Deiter cells of these two Cxs, apart from isolated Cx26 and Cx30 labeling in the same area, suggestive of both homomeric/homotypic pattern and hybrid pattern (heteromeric or heterotypic). Cx30, Cx26 and Connexin 36 (Cx36) immunoreactivity was also associated with spiral ganglion type I neurons, the latter being a gap junction protein specific to neurons. Gap–junction-based electrical synapses are not known to occur in mammalian auditory system other than in bats where they may play a role for fast electrical nerve transmission useful for echolocation. Their potential role in the processing of human auditory nerve signaling as well as non-GJ roles of the connexins in human cochlea is discussed.