Age-related increase in PKC gamma expression in the cochlear nucleus of hearing impaired C57BL/6J and BALB/c mice.
Age-dependent alteration in cellular signaling is implicated in the onset of age-related hearing loss (presbycusis). The gamma subtype of protein kinase C (PKCγ) is a PKC isoenzyme exclusively expressed in central nervous system but its potential role in the presbycusis remains unclear. Using two presbycusis-like animal models (C57BL/6J strain and BALB/c strain), the auditory thresholds were assessed by auditory brainstem response (ABR) in young (2-month-old), adult (8-month-old) and old (24-month-old) groups, and the localization and expression of PKCγ in the cochlear nucleus (CN) was examined by immunohistochemistry, Western blotting and Real-Time PCR. The results showed that PKCγ immmunoreactive (-ir) neurons were mainly concentrated in the molecular layer and fusiform layer of the dorsal CN (DCN) and their number was increased significantly with aging (p<0.05). Moreover, compared with 2-month-old mice, PKCγ expression in the CN at both protein and mRNA levels was significantly increased in the 8-month-old mice and 24-month-old mice (p<0.05). Thus our findings demonstrate a potential link between the increased PKCγ expression and the age-related hearing loss in these mice, suggesting novel strategies for the prevention and therapy of age-associated auditory disorders.
Department of Anatomy, Histology and Embryology, K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an 710032, China.
Zhen-Zhen
ZZ
Kou
Yong
Y
Zhang
Ting
T
Zhang
Hui
H
Li
Yun-Qing
YQ
Li
D000367:Age Factors; D000375:Aging / Q000502:physiology*; D000818:Animals; D001309:Auditory Threshold / Q000502:physiology; D017626:Cochlear Nucleus / Q000166:cytology / Q000378:metabolism*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D023421:Models, Animal; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D011304:Presbycusis / Q000235:genetics / Q000378:metabolism*; D011493:Protein Kinase C / Q000235:genetics* / Q000378:metabolism*
C087857:protein kinase C gamma; D011493:Protein Kinase C