Over-expression of X-linked inhibitor of apoptosis protein slows presbycusis in C57BL/6J mice.
Apoptosis of cochlear cells plays a significant role in age-related hearing loss or presbycusis. In this study, we evaluated whether over-expression of the anti-apoptotic protein known as X-linked Inhibitor of Apoptosis Protein (XIAP) slows the development of presbycusis. We compared the age-related hearing loss between transgenic (TG) mice that over-express human XIAP tagged with 6-Myc (Myc-XIAP) on a pure C57BL/6J genetic background with wild-type (WT) littermates by measuring auditory brainstem responses. The result showed that TG mice developed hearing loss considerably more slowly than WT littermates, primarily within the high-frequency range. The average total hair cell loss was significantly less in TG mice than WT littermates. Although levels of Myc-XIAP in the ear remained constant at 2 and 14 months, there was a marked increase in the amount of endogenous XIAP from 2 to 14 months in the cochlea, but not in the brain, in both genotypes. These results suggest that XIAP over-expression reduces age-related hearing loss and hair cell death in the cochlea.
Wang
Jian
J
The Affiliated Sixth People's Hospital, Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China. jian.wang@dal.ca
Menchenton
Trevor
T
Yin
Shankai
S
Yu
Zhiping
Z
Bance
Manohar
M
Morris
David P
DP
Moore
Craig S
CS
Korneluk
Robert G
RG
Robertson
George S
GS