Homocysteine-Mediated Modulation of Mitochondrial Dynamics in Retinal Ganglion Cells
Homocysteine-Mediated Modulation of Mitochondrial Dynamics in Retinal Ganglion Cells
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DOI：
10.1167/iovs.11-7256
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发表时间：
2011-07-01
影响因子：
4.4
通讯作者：
Smith, Sylvia B.
中科院分区：
文献类型：
--
作者：
Ganapathy, Preethi S.;Perry, Richard L.;Smith, Sylvia B.
目的.目的探讨高同型半胱氨酸对视网膜神经节细胞线粒体动力学的影响。胱硫醚-β-合酶（cbs）缺陷的小鼠被用作高同型半胱氨酸血症的模型。在cbs（+/-）神经视网膜上进行Opa 1和Fis 1的基因和蛋白表达分析。对视网膜神经节细胞轴突内的线粒体进行系统的超微结构分析，以测量线粒体与轴突壁之间的面积、长度、宽度和距离。原代培养小鼠神经节细胞，用同型半胱氨酸处理，检测Opa 1和Fis 1蛋白水平、单位长度神经突起的线粒体数量和切割的caspase-3水平。与野生型相比，cbs（+/-）神经视网膜中Opa 1和Fis 1蛋白水平分别升高至191.00% +/- 26.40%和226.20% +/-4.57%。与野生型相比，cbs（+/-）视网膜的线粒体在所有研究参数中都较小，包括面积（0.32 +/- 0.01 μ m（2）vs. 0.42 +/- 0.02 μ m（2））。与对照组相比，用同型半胱氨酸处理的原代神经节细胞Opa 1和Fis 1蛋白升高，单位长度神经突的线粒体数量显著增加（0.1781 +/- 0.017 vs. 0.1156 +/- 0.012），裂解的caspase-3水平显著升高。这项研究提供了第一个证据表明，同型半胱氨酸诱导的神经节细胞损失涉及线粒体动力学失调，在体内和体外。目前的数据表明，增加线粒体分裂作为一种新的机制同型半胱氨酸毒性神经元。特别相关的是青光眼和阿尔茨海默病，与高同型半胱氨酸血症相关的神经变性疾病，并且最近在其发病机制中涉及线粒体分裂增加。（Invest Ophthalmol维斯科学。2011; 52：5551-5558）DOI：10.1167/iovs.11-7256
PURPOSE. To evaluate the effect of excess homocysteine on the regulation of retinal ganglion cell mitochondrial dynamics.METHODS. Mice deficient in cystathionine-beta-synthase (cbs) were used as a model of hyperhomocysteinemia. Gene and protein expression analyses of Opa1 and Fis1 were performed on cbs(+/-) neural retinas. Mitochondria within retinal ganglion cell axons underwent systematic ultrastructural analysis to measure area, length, width, and the distance between the mitochondria and the axon wall. Primary mouse ganglion cells were cultured, treated with homocysteine, and assessed for levels of Opa1 and Fis1 protein, the number of mitochondria per length of neurite, and levels of cleaved caspase-3.RESULTS. Opa1 and Fis1 protein levels in cbs(+/-) neural retinas were elevated to 191.00% +/- 26.40% and 226.20% +/- 4.57%, respectively, compared with wild-type. Mitochondria of cbs(+/-) retinas were smaller in all parameters studied, including area (0.32 +/- 0.01 mu m(2) vs. 0.42 +/- 0.02 mu m(2)), compared with wild-type. Primary ganglion cells treated with homocysteine had elevations in Opa1 and Fis1 proteins, a significantly higher number of mitochondria per length of neurite (0.1781 +/- 0.017 vs. 0.1156 +/- 0.012), and significantly higher levels of cleaved caspase-3 compared with control.CONCLUSIONS. This study provides the first evidence that homocysteine-induced ganglion cell loss involves the dysregulation of mitochondrial dynamics, both in vivo and in vitro. The present data suggest increased mitochondrial fission as a novel mechanism of homocysteine toxicity to neurons. Of particular relevance are glaucoma and Alzheimer's disease, neurodegenerative diseases that are associated with hyperhomocysteinemia and, more recently, have implicated increased mitochondrial fission in their pathogeneses. (Invest Ophthalmol Vis Sci. 2011; 52: 5551-5558) DOI: 10.1167/iovs.11-7256