Expression And Significance Of MiRNA-34a-5p And SIRT6 In Cochlea Of Mice At Different Ages

Objective: By detecting the expression of miRNA-34a-5p and SIRT6 in the cochlear tissue of mice at different ages and presbycusis model mice,the changes of miRNA-34a-5p and SIRT6 in the cochlea of mice at different ages and the interaction and significance in the occurrence and development of presbycusis were investigated.Methods: Ten 2-month-old SPF C57BL/6 mice were used to create a mouse model of presbycusis using the D-galactose modeling method,and after successful modeling,six mice were selected randomly for this study.Six C57BL/6 mice at 4 different growth and development time points(3 months,6 months,12 months and 16 months)were anesthetized with intraperitoneal injection of 2% pentobarbital sodium.The mice in each group were decapitated,and the auditory vesicles were rapidly removed.The cochlea samples were washed with isotonic saline,isolated the basement membraneand.The expression of miRNA-34a-5p and SIRT6 in the basement membraneand tissues of D-galactose presbycusis model mice at each age was detected by qRT-PCR.The differences between the groups were compared,and the changes of miRNA-34a-5p and SIRT6 and the correlation of their expression in the cochlear tissues of mice in different groups were analyzed.Results: There were significant differences in the relative expression levels of miRNA-34a-5p and SIRT6 proteins in the basilar membrane tissues of the cochlea of C57BL/6 mice at 3 months,6 months,12 months and 16 months of age(F = 9.437,P< 0.001;F = 20.108,P < 0.001);With the increase of age,miRNA-34a-5p expression levels increased in turn,and there were significant differences between the two groups at each age(P < 0.05).Among them,the D-galactose senile deafness model group was significantly different from the 3-month-old group(P < 0.05),and compared with the6-month-old group(P < 0.05),while compared with the 12-month-old group,the difference was not statistically significant(P > 0.05),and compared with the 16-monthold group,the difference was not statistically significant(P > 0.05).With the increase of age,the expression level of SIRT6 decreased in turn,and there were significant differences between the two groups at each age(P < 0.05),in which the D-galactose senile deafness model group was significantly different from the 3-month-old group(P< 0.05),compared with the 6-month-old group(P < 0.05),compared with the 12-month-old group(P < 0.05),and compared with the 16-month-old group,the difference was not statistically significant(P > 0.05).Pearson correlation analysis showed that the expression of miRNA-34a-5p and SIRT6 was negatively correlated in the basilar membrane tissue of mouse cochlea(r =-0.591,P > 0.05).Conclusion: The expression level of miRNA-34a-5p in mouse cochlear tissue increased with mouse age,and the expression level of SIRT6 in mouse cochlear tissue decreased with mouse age,which was negatively correlated,of which miRNA-34a-5p may promote the occurrence and development of presbycusis,while SIRT6 may inhibit the occurrence and development of presbycusis;between miRNA-34a-5p and SIRT6 may regulate the process of presbycusis by jointly affecting cochlear function.