Vol.100 No.5 contentsPRACTICA OTO-RHINO-LARYNGOLOGICA
Vol. 100 No. 5 May 2007
Hematopoietic Stem Cells Prevent Hair Cell Death after
Transient Cochlear Ischemia through Upregulation of GDNF
Tadashi Yoshida
(Ehime University School of Medicine)
The transplantation of hematopoietic stem cells (HSCs) is regarded to be a potential approach for promoting the repair of damaged organs. Here, we investigated the influence of hematopoietic stem cells on progressive hair cell degeneration after cochlear ischemia in gerbils. Intrascalar injection of HSCs prevented ischemia-induced hair cell degeneration and ameliorated hearing impairment. The administration of HSCs apparently augmented the upregulation of ischemia-induced GDNF, which is proved to inhibit ischemic cochlear damage. A tracking study revealed that HSCs injected into cochlear were retained in the perilymphatic space of the cochlea, although they neither transdifferentiated into cochlear cell types nor fused with injured hair cells. These results suggested that HSCs have therapeutic potential by preventing ischemia-induced hearing loss, probably through their paracrine effects. We concluded that the direct administration of HSCs into the perilymphatic space can be a new therapeutic strategy for sudden-onset hearing loss due to cochlear ischemia.
Key words : hematopoietic stem cell, cochlear ischemia, glial cell-derived neurotrophic factor (GDNF), hearing loss