Differential brain-derived neurotrophic factor and transforming growth factor-beta expression in the rat cochlea following deafness.
Brain derived neurotrophic factor (BDNF) and transforming growth factor-beta (TGFbeta) subtypes have demonstrated their importance in cochlear functions. The aim of this study was to determine gene and protein expression patterns of BDNF, TGFbeta1/2 and their main receptors trkB and TGFbetaR1/R2 in the auditory nerve and inferior colliculus of normal hearing and deafened rats by reverse-transcriptase polymerase chain reaction and immunohistochemistry. Deafening was performed by cochlear injection of neomycin (10%). Significant gene expression changes were not found in the inferior colliculus after deafness; however, in the auditory nerve, BDNF, TGFbeta1 and TGFbetaR1 mRNA in particular were upregulated. Additionally, BDNF protein and the cytokines were found to be expressed in the auditory nerve after hair cell loss. These data indicate the importance of BDNF and TGFbeta1 as endogenous survival factors.
Wissel
Kirsten
K
Department of Otolaryngology, Medical University of Hannover, Hannover, Germany.
Wefstaedt
Patrick
P
Miller
Josef M
JM
Lenarz
Thomas
T
Stöver
Timo
T
D000818:Animals; D015152:Blotting, Northern / Q000379:methods; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism*; D003051:Cochlea / Q000378:metabolism*; D003638:Deafness / Q000378:metabolism / Q000473:pathology*; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000502:physiology*; D007150:Immunohistochemistry / Q000379:methods; D007245:Inferior Colliculi / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011917:Rats, Inbred Lew; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D000159:Vestibulocochlear Nerve / Q000378:metabolism
D019208:Brain-Derived Neurotrophic Factor; D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta