Ko Ah-Reum, Hyun Hye-Won, Min Su-Ji, Kim Ji-Eun
Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University Chuncheon, South Korea.
Front Cell Neurosci. 2016 May 18;10:124. doi: 10.3389/fncel.2016.00124. eCollection 2016.
The response and susceptibility to astroglial degenerations are relevant to the distinctive properties of astrocytes in a hemodynamic-independent manner following status epilepticus (SE). Since impaired mitochondrial fission plays an important role in mitosis, apoptosis and programmed necrosis, we investigated whether the unique pattern of mitochondrial dynamics is involved in the characteristics of astroglial death induced by SE. In the present study, SE induced astroglial apoptosis in the molecular layer of the dentate gyrus, accompanied by decreased mitochondrial length. In contrast, clasmatodendritic (autophagic) astrocytes in the CA1 region showed mitochondrial elongation induced by SE. Mdivi-1 (an inhibitor of mitochondrial fission) effectively attenuated astroglial apoptosis, but WY14643 (an enhancer of mitochondrial fission) aggravated it. In addition, Mdivi-1 accelerated clasmatodendritic changes in astrocytes. These regional specific mitochondrial dynamics in astrocytes were closely correlated with dynamin-related protein 1 (DRP1; a mitochondrial fission protein) phosphorylation, not optic atrophy 1 (OPA1; a mitochondrial fusion protein) expression. To the best of our knowledge, the present data demonstrate for the first time the novel role of DRP1-mediated mitochondrial fission in astroglial loss. Thus, the present findings suggest that the differential astroglial mitochondrial dynamics may participate in the distinct characteristics of astroglial death induced by SE.
癫痫持续状态(SE)后,星形胶质细胞对退行性变的反应和易感性与星形胶质细胞的独特特性以血流动力学非依赖方式相关。由于线粒体裂变受损在有丝分裂、凋亡和程序性坏死中起重要作用,我们研究了线粒体动力学的独特模式是否参与SE诱导的星形胶质细胞死亡特征。在本研究中,SE诱导齿状回分子层星形胶质细胞凋亡,同时线粒体长度缩短。相比之下,CA1区的树突断裂(自噬)星形胶质细胞显示SE诱导的线粒体延长。Mdivi-1(一种线粒体裂变抑制剂)有效减轻星形胶质细胞凋亡,但WY14643(一种线粒体裂变增强剂)则加重凋亡。此外,Mdivi-1加速星形胶质细胞的树突断裂变化。星形胶质细胞中这些区域特异性的线粒体动力学与动力相关蛋白1(DRP1;一种线粒体裂变蛋白)磷酸化密切相关,而非视神经萎缩蛋白1(OPA1;一种线粒体融合蛋白)的表达。据我们所知,本数据首次证明DRP1介导的线粒体裂变在星形胶质细胞丢失中的新作用。因此,本研究结果表明,不同的星形胶质细胞线粒体动力学可能参与SE诱导的星形胶质细胞死亡的不同特征。