Bax在D-半乳糖诱导的老化大鼠耳蜗中的作用

发布时间：2018-03-23 08:10

本文选题：Bax　切入点：老化　出处：《中华耳科学杂志》2014年03期 　论文类型：期刊论文

【摘要】：目的研究Bax介导的细胞凋亡在D-半乳糖诱导的老化大鼠耳蜗中的作用,探讨老年性耳聋外周听觉系统细胞凋亡的发生机制。方法 36只1月龄雄性Spragua-Dawley大鼠随机分成2组(各18只):1 D-半乳糖组:每日颈背部皮下注射D-半乳糖(500mg/kg),连续8周;2对照组:每日颈背部皮下注射同体积的生理盐水,连续8周。造模完成后,取两组大鼠耳蜗,利用实时定量PCR检测线粒体DNA(mitochondrial DNA,mt DNA)普遍缺失(common deletion,CD)的累积;利用western blot检测Bax蛋白的表达;利用免疫组织化学检测Cleaved caspase-3蛋白的表达;利用原位末端转移酶标记(terminal deoxynucleotidyl transferase(Td T)-mediated deoxyuridine triphosphate(d UTP)nick-endlabelling,TUNEL)染色检测大鼠耳蜗细胞凋亡发生的情况。所有实验数据采用两样本的t检验进行分析。结果和对照组的大鼠相比较,D-半乳糖诱导的老化大鼠mt DNA CD的累积在耳蜗组织中明显增多,差异有统计学意义(t值为6.631,P值0.01);Bax和Cleaved caspase-3蛋白的表达在耳蜗组织中明显增强,差异有统计学意义(t值分别为20.914、20.043,P值均0.01)。对照组的大鼠耳蜗没有检测到凋亡细胞,而D-半乳糖诱导的老化大鼠耳蜗底回血管纹检测到少量凋亡细胞。结论 Bax介导的细胞凋亡参与了D-半乳糖诱导的耳蜗老化过程,可能是导致老年性耳聋外周听觉系统细胞凋亡发生的重要原因。
[Abstract]:Objective to study the role of Bax mediated apoptosis in aging rat cochlea induced by D-galactose. To investigate the mechanism of apoptosis in peripheral auditory system of presbycusis. Methods 36 male Spragua-Dawley rats aged 1 month were randomly divided into two groups (18 rats in each group): subcutaneously injected Dgalactose 500 mg / kg daily into the neck and back for 8 consecutive years. Week 2 control group: daily subcutaneous injection of the same volume of normal saline to the neck and back, After 8 weeks, cochlea were taken from two groups of rats. The accumulation of common deletion of mitochondrial DNA(mitochondrial mt DNA was detected by real-time quantitative PCR, the expression of Bax protein was detected by western blot, the expression of Cleaved caspase-3 protein was detected by immunohistochemistry. Terminal deoxynucleotidyl transferase(Td T)-mediated deoxyuridine triphosphate(d UTPnick-endlabelling Tunel staining was used to detect apoptosis of cochlear cells in rats. All experimental data were analyzed by t-test of two samples. The results were compared with those of control rats. The accumulation of Mt DNA CD in the cochlea of aged rats induced by lactose was significantly increased. The expression of Bax and Cleaved caspase-3 were significantly increased in cochlea, and the difference was 20.914 and 20.043P, respectively. No apoptotic cells were detected in the cochlea of the control group. A small number of apoptotic cells were detected in the vascular stria of the basal gyrus of the cochlea of aging rats induced by D-galactose. Conclusion the apoptosis mediated by Bax is involved in the aging process of the cochlea induced by D-galactose. It may be an important cause of apoptosis in peripheral auditory system of presbycusis.
【作者单位】：广东医学院附属南山医院耳鼻咽喉科;广西医科大学;
【基金】：深圳市南山区技术研发和创意设计项目分项资金(南科研卫2012014号)资助
【分类号】：R764.436

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