Histological and functional analysis of inner ear stem cell xenotransplantation in the cochlea of guinea pigs with induced hearing loss / Análise histológica e funcional de xenotransplante de células-tronco da orelha interna de camundongos em cócleas de cobaias com perda auditiva induzida
AUTOR(ES)
Luiz Carlos de Melo Barboza Junior
FONTE
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia
DATA DE PUBLICAÇÃO
05/09/2012
RESUMO
Background: In mammals, damage to sensory receptor cells (hair cells) of the inner ear results in permanent sensorineural hearing loss. Here we investigate whether, after transplantation, neonatal mouse inner ear stem cells (mIESCs) can survive and integrate into basal turns of neomycin-injured guinea pig cochleas. We also studied the potential effects of the cell transplantation on the auditory function. Methods: Eight adult guinea pigs were deafened by intratympanic neomycin delivery. After 7 days, the animals were randomly divided in two groups. Study group (n=4) received transplantation to the scala tympani of 1 X 105 LacZ-positive mIESCs in culture medium. Control group (n=4) received culture medium only. Fourteen days after the transplantation, functional analyses were performed by auditory brainstem responses (ABR) and the animals were sacrificed. The presence and distribution of mIESCs were evaluated by immunohistochemistry of longitudinal sections of the cochlea from the study group. Non-parametric tests were used for statistical analysis. Results: The intratympanic neomycin delivery damaged hair cells and increased auditory thresholds prior to cell transplantation. There were no significant differences between auditory brainstem thresholds before and after transplantation in individual guinea pigs. Some mIESCs have been observed in all scalae of basal turns of the injured cochleas, and a proportion of those cells expressed the hair cell marker myosin VIIa. Some transplanted mIESCs integrated in the cochlear basilar membrane. There was no evidence of inflammatory infiltration in any of the guinea pigs. Conclusions: Although implanted mIESCs showed no obvious effect on auditory thresholds, our experiments showed survival, migration, expression of hair cell marker and integration of transplanted cells
ASSUNTO(S)
camundongos cell therapy cell transplantation células-tronco cobaias cochlea cóclea guinea pigs regeneração regeneration stem cells xenotransplantation xenotransplante hearing loss mice perda auditiva terapia celular transplante de células
