Expression of the GDNF family members and their receptors in the mature rat cochlea.
The GDNF family comprises glial cell line-derived neurotrophic factor (GDNF) and the related proteins neurturin, artemin and persephin, which form a subgroup of the TGF-beta superfamily of growth factors. All four neurotrophic factors provide neuronal cell protection and cell survival. GDNF expression was found in the cochlea, and GDNF has been shown to be effective for inner ear protection from drugs and noise-induced insults. As the other members of the GDNF family also provide protective effects on neuronal cells, they may play important roles in the inner ear. We used RT-PCR to examine the expression of GDNF, neurturin, artemin, persephin and their receptors GFRalpha-1, GFRalpha-2, GFRalpha-3 and c-ret in whole rat cochlea as well as in functionally different subfractions (modiolus and sensorineural epithelium/lateral wall) and compared the levels of neurotrophin and receptor mRNAs in the cochlea to those in substantia nigra brain region. Our results demonstrate the expression of all GDNF family members and their receptors in cochlea and substantia nigra. However, the relative levels of mRNA were different for several genes tested in subfractions of the cochlea and/or compared to expression levels in substantia nigra. The presence of mRNA for all four members of the GDNF family and their preferred receptors in the rat cochlea suggests potential functional importance of these neurotrophic factors as protection and survival factors in the inner ear.
Stöver
T
T
Department of Otolaryngology/Head and Neck Surgery, Kresge Hearing Research Institute, The University of Michigan Medical School, Ann Arbor, MI 48109-0506, USA.
Gong
T L
TL
Cho
Y
Y
Altschuler
R A
RA
Lomax
M I
MI
D000818:Animals; D003051:Cochlea / Q000378:metabolism*; D029721:Drosophila Proteins; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D008297:Male; D008562:Membrane Glycoproteins; D009414:Nerve Growth Factors / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051096:Proto-Oncogene Proteins c-ret; D051381:Rats; D017207:Rats, Sprague-Dawley; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism; D017475:Receptors, Nerve Growth Factor; D012269:Ribosomal Proteins / Q000378:metabolism; D013378:Substantia Nigra / Q000378:metabolism
D029721:Drosophila Proteins; C495041:Gdnf protein, rat; C494989:Gfra1 protein, rat; C494992:Gfra2 protein, rat; C494995:Gfra3 protein, rat; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D008562:Membrane Glycoproteins; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D011518:Proto-Oncogene Proteins; D011956:Receptors, Cell Surface; D017475:Receptors, Nerve Growth Factor; D012269:Ribosomal Proteins; C110758:persephin; C023509:ribosomal protein S16; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila; C495001:Ret protein, rat