D-半乳糖诱导拟老化大鼠内耳中线粒体外膜易位酶tom40，tom20及线粒体内膜易位酶tim23的表达研究

发布时间：2018-05-03 15:26

本文选题：tom40 + tom20　；参考：《华中科技大学》2011年硕士论文

【摘要】：目的:探讨线粒体蛋白输入功能变化在老年性聋发病机制中的作用,为老年性聋的预防及治疗提供新的思路。方法:96只1月龄雌性Wistar大鼠随机分为A、B、C、D四组,每组24只。其中,B、C、D组为实验组,A组为空白对照组,分别给予每日颈部皮下注射D-半乳糖150mg/kg,300mg/kg,500mg/kg和等量生理盐水,共8周。听性脑干反应(ABR)检测4组大鼠给药前后听阈。实时荧光定量PCR检测给药后各组大鼠内耳组织中线粒体DNA 4834 bp缺失突变率。实时荧光定量RT-PCR检测给药后各组大鼠内耳中tom40,tom20,tim23 mRNA水平的表达变化。Western blot法检测给药后各组大鼠内耳中tom40,tom20,tim23蛋白水平的表达变化。结果:四组间给药前后ABR听阈提高值无明显差异(p0.05)。线粒体DNA 4834 bp缺失突变率在各组分别为:A组3.91%±0.33%,B组9.16%±0.32%,C组11.65%±0.58%,D组15.09%±0.94%,与A组相比,B,C,D三组D-半乳糖剂量组大鼠内耳组织中CD缺失率均显著升高(p0.05) ,且B,C,D各不同剂量组间,CD缺失率均有显著性差异(p0.05)。tom40,tom20,tim23 mRNA水平的表达在各组间无明显差异(p0.05)。tom40,tom20蛋白水平的表达除A、B两组间无明显差异外(p0.05),其余各组间差异均有统计学意义,且随半乳糖剂量的增大显著降低(p0.05),tim23蛋白水平的表达在各组间无明显差异(p0.05)。结论:tom40,tom20蛋白表达水平在拟老化大鼠内耳组织中存在着不同程度的降低,提示在内耳组织老化的发生过程中线粒体蛋白输入转运系统可能广泛受累,其中tom40和tom20的降低较早出现并且较为严重,会直接影响TOM复合体功能,并进一步引起核编码线粒体蛋白输入障碍。
[Abstract]:Objective: to explore the role of mitochondrial protein input function in the pathogenesis of presbycusis and to provide a new idea for the prevention and treatment of presbycusis. Methods one month old female Wistar rats were randomly divided into four groups, 24 rats in each group. Group D was treated by subcutaneous injection of D-galactose (150mg / kg) and saline (300mg / kg) and saline for 8 weeks (n = 8), and the control group (n = 10) was given subcutaneous injection of D-galactose (150 mg / kg) and normal saline (n = 500 mg / kg) for 8 weeks. Auditory brainstem response (ABR) was used to detect the hearing threshold before and after administration. The deletion rate of mitochondrial DNA 4834 BP in the inner ear of rats was detected by real-time fluorescence quantitative PCR. Real-time fluorescence quantitative RT-PCR was used to detect the expression of tom40 tom20tim23 mRNA in the inner ear of rats in each group. Western blot was used to detect the expression of tom40 tom20tim23 protein in the inner ear of each group. Results: there was no significant difference in ABR hearing threshold between the four groups before and after administration. The deletion rate of mitochondrial DNA 4834 BP was 3.91% 卤0.33 in group B and 9.16% 卤0.32 in group B respectively. The deletion rate of CD in group D was 15.09% 卤0.94% in group D, which was significantly higher than that in group A (P 0.05). In addition, there was no significant difference in the expression of p0.05N. Tom40m20tim23 mRNA between the two groups. The expression of p0.05n.tom40tom20 protein was not significantly different between the two groups, except that there was no significant difference between the two groups (P 0.05), and there was significant difference between the other groups, and there was no significant difference between the two groups in the expression of p0. 05%, p0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, respectively. With the increase of galactose dose, the expression of p0.05 titim23 protein was significantly decreased in each group. There was no significant difference in p0.05 protein expression among the three groups. Conclusion the level of the protein expression in the inner ear of the aged rats is decreased to some extent, which suggests that the mitochondrial protein input transport system may be involved extensively during the aging of the inner ear tissue, and it is suggested that the mitochondrial protein input transport system may be involved extensively during the aging process of the inner ear tissue. The decrease of tom40 and tom20 appeared earlier and more serious, which directly affected the function of TOM complex and further caused the obstruction of nuclear coding mitochondrial protein input.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R764.43

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