Effects of healthy ear compound of traditional Chinese medicine against age-induced apoptosis on cochlear spiral ganglion neurons in C57BL/6J mice and research on mechanisms by regulating caspase-3
10.3760/cma.j.issn.0254-9026.2016.12.019
- VernacularTitle:复方健耳剂对抗小鼠老年性耳蜗螺旋神经节神经元凋亡效应及机制研究
- Author:
Weijun XUAN
;
Dalian DING
;
Yi XUAN
;
Zhuang CHEN
;
Liyi HUANG
;
Yulong WEI
;
Junbo TANG
- Keywords:
Presbycusis;
Cochlear;
Spiral ganglion;
Drugs Chinese herbal;
Apoptosis
- From:
Chinese Journal of Geriatrics
2016;35(12):1329-1333
- CountryChina
- Language:Chinese
-
Abstract:
Objective To explore the damage of spiral ganglion neurons(SGNs),the protective effects of different dosages of healthy ear compound (HEC)from traditional Chinese medicine(TCM) against age-induced SGNs degeneration and its possible mechanism in spiral ganglion neurons(SGNs)of C57BL/6J mice.Methods Totally 36 C57BL/6J mice just after ablactation were randomly divided into four groups.Normal control group (n =6)drank tap water daily from ablactation to 2 months old.Ageing-related SGNs apoptosis control group(n=12)drank tap water daily from ablactation to 7 months old.High dose TCM group(n=12)at drank 3.65 g/kg/d of HEC from ablactation to 7 months old.Low dose TCM group(n=6)drank 0.91 g/kg/d of HEC from ablactation to 7 months old.The animal cochleae were immediately removed at the termination of the experiment.In each group,the cochleae of 6 animals were used for paraffin embedding,slicing and toluidine blue staining to observe neuronal morphological changes.The caspase-3 mRNA expression study was performed by real-time PCR technique in 6 cochleae of High dose TCM group and ageing-related SGNs apoptosis control group.Results The morphological structure of cochlear SGNs represented healthy and normal density in normal control group at 2 months old.In contrast,amount or density of SGNs in cochlear basilar part was significantly damaged and reduced in ageing-related SGNs apoptosis control group at 7 months old(P＜ 0.001).But the high dose TCM group at 7 months of age was similar to the normal control group at 2 months old in morphological structure,amount or density of SGNs(P＞0.05).The low dose TCM group was significantly different from other 3 groups in amount or density of SGNs (P＜0.001).However,SGNs in the middle part and apical part showed integrity in each group.In addition,the expression level of caspase-3 in the cochlea of high dose TCM group was also obviously different with age-related SGNs apoptosis control group(P＜0.01) Conclusions Ageing-related damage of SGNs in C57BL/6J mice begins from the base of cochlea and progresses towards the apex.The HEC of TCM could significantly protect SGNs against age-induced apoptosis in SGNs.The efficacy of the high dose TCM is better than that of the low dose TCM.Its SGNs protective mechanisms might be related to involving the caspase-mediated cell apoptotic pathway.
