| Objective: Through the study of Transmem-brane protein 16A(TMEM16A)and Transmem-brane protein 16B(TMEM16B),the molecular components of calcium-activated chloride channels(CaCCs),in different aged guinea pigs,striae vascularis(post-natal day(PND)14,PND 90,1-year-old and D-galactose),and the relationship between the expression of them with age,and thus infer that the role them in senile deafness.Methods: The aging model was prepared from the subcutaneous injection of the D-galactose,then it was tested by detected the Morris water maze,SOD activity and MDA content.To detect the change of hearing in guinea pigs of different age groups by auditory brainstem response(ABR);using immunofluorescence to stain TMEM16 A and TMEM16 B in striae vascularis,and to research the temporal distribution in them;Using QRT-PCR and Westen blot to detect the mRNA and and protein levels of TMEM16 A and TMEM16 B in striae vascularis;analysing the function and the possible mechanism of TMEM16 A and TMEM16 B in hearing of different age in guinea pigs.Results:(1)After the aging model was finished,it was found that the guinea pigs in the D-gal group had less food consumption,less active activity,andwithered hair color,and hair loss serious;Morris water maze test showed that the experimental groups of guinea pigs had lower escape latency(P<0.01,n=10)younger guinea pigs decreased escape latency(P<0.01,n=10);The biochemical testing found that the experimental group exhitbited increased guinea pig’s SOD activity,and decreased the content of MDA(P<0.01,n=10);Besides,the threshold of experiment group was higher than that of young guinea pigs in ABR(P<0.01,n=10).(2)The ABR test results showed that the threshold increased with age,but only the difference between 3-month-old and the aging group was statistically significant(P <0.01,n =10).(3)Immunofluorescence showed TMEM16 A and TMEM1616 B expression in striae vascularis of guinea pig cochlear in different age groups.And the fluorescence intensity increased with age and decreased at D-gal group.(4)QRT-PCR results showed that the TMEM16 A and TMEM16 B in stria vascularis of cochlea in guinea pigs change with age in mRNA level.The expression increased with the age of guinea pig,but decreased significantly at D-gal group.The different was statistically significant beweent D-gal group and other groups in addition to 2 w(P<0.05,n=6).(5)Westen blot showed that the expression of TMEM16 A and TMEM16 B in different age groups of striae vascularis in guinea pig cochlea were different.The expression increased with the age,but it of the D-gal group decreased significantly.The different was statistically significant beweent D-gal group and other groups(except for 2 w).(P<0.05,n=6).Conclusions: Down-regulation of TMEM16 A and TMEM16 B in cochlea of guinea pigs may be associnted with age-related hearing loss. |
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