The expression of PNUTS in the cochlea of D-galactose induced ageing mice / 天津医药

ABSTRACT

Objective To observe the expression of protein phosphates 1 nuclear targeting subunit (PNUTS) in the cochlea of D-galactose induced ageing mice. Methods Twenty Kunming mice, six weeks old, cleaning degree, were randomly divided into two groups, control group and D-galactose group, ten mice for each group. Mice in D-galactose group were administrated with D-galactose at a dose of 800 mg/(kg · d) by subcutaneous injection for eight weeks. Mice in control group were injected with the same volume of saline. After eight weeks, auditory brainstem responses (ABR) were collected to test the hearing thresholds of mice. Western blot assay was used to detect expressions of PNUTS and p53 protein. The expression and distribution of PNUTS in the cochlear Corti, spiral ganglion and striavascularis cells were observed by immunohistochemical (IHC) staining. Results There were no significant differences in ABRs at 8, 12 and 24 kHz between two groups. Protein expressions of PNUTS were located in the cochlear hair cells, spiral ganglion cells and striavascularis cells, and the expression level of cochlea was significantly decreased in D-galactose group than that in control group ( P<0.05). The expression level of p53 protein was significantly increased in D-galactose group than that in control group (P<0.01). Conclusion PNUTS is expressed in the normal mouse cochlea, and which is down-regulated in the cochlea of ageing mice induced by D-galactose.