Immunohistological analysis of neurturin and its receptors in human cochlea

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• 作者：Wei Liu ; Helge Rask-Andersen
• 关键词：Human cochlea ; Spiral ganglion neuron ; GDNF family ligand ; Neurturin ; cRet ; GFR伪-1 ; GFR伪-2
• 刊名：Auris Nasus Larynx
• 出版年：April, 2014
• 年：2014
• 卷：41
• 期：2
• 页码：172-178
• 全文大小：2508 K

文摘

Objective

Difficulties in obtaining properly preserved human cochlea have been a major obstacle to in vitro study of this deeply located and hard bone-fortressed hearing organ. Our study aimed at investigating GDNF family ligands (GFLs) and their receptors in the human cochleae that were surgically obtained during a transcochlear approach dealing with life-threatening, intra-cranial meningiomas.

Methods

The specimens were properly fixed with 4% paraformaldehyde in the operating room. By using immunohistochemical techniques, distribution of GDNF, Neurturin (NTN, one member of GFLs), as well as cRet, GFR伪-1 and GFR伪-2 receptors in the human cochleae was investigated. Five cochleae from five adult patients were processed for the study. The patients had normal hearing threshold before operation.

Results

cRet receptor immunoreactivity was seen in the spiral ganglion neurons, mainly inside the cell bodies but rarely in the nerve fibers and not in the organ of Corti. Immunolabeling for GFR伪-1 and GFR伪-2 receptors was identified mainly in the cell bodies of the spiral neurons than in the nerve fibers. In the organ of Corti, GFR伪-1 immunostaining could be demonstrated in the Deiters鈥?cells, Hensen cells, inner pillar cells, and weakly in the inner hair cells but not in the outer hair cells; no structures in the organ of Corti were labeled with GFR伪-2 receptor antibody. NTN immunostaining was found in the supporting cells of organ of Corti, including Deiters鈥?cells, Hensen cells as well as Claudius鈥?cells. In the spiral ganglia, NTN immunostaining was seen in both the cell bodies and the nerve fibers of neurons. GDNF immunoreactivity was not revealed in human cochlea.

Conclusion

Surgically obtained human cochleae were properly fixed and underwent immunohistochemical investigation of neurotrophic elements. NTN and its receptors discovered in current study can be responsible for the unique neuronal survival properties in human spiral ganglion (hSG); a prerequisite for the function of cochlear implants.