Park Eunkuk, Choi Seok Keun, Kang Sung Wook, Pak Youngmi Kim, Lee Gi-Ja, Chung Joo-Ho, Park Hun-Kuk
Department of Medical Genetics, Ajou University School of Medicine, Suwon 443-721, Republic of Korea.
Department of Neurosurgery, Kyung Hee University Hospital, Seoul 130-702, Republic of Korea.
Biomed Pharmacother. 2015 Apr;71:15-20. doi: 10.1016/j.biopha.2015.02.007. Epub 2015 Feb 18.
Mitochondria play a central role in cell survival, and apoptotic cell death is associated with morphological changes in mitochondria. Quantification of the morphological and mechanical property changes in brain mitochondria is useful for evaluating the degree of ischemic injury and the neuroprotective effects of various drugs. This study was performed to investigate the changes in brain mitochondria in an 11-vessel occlusion ischemic model treated with magnesium sulfate (MgSO4), utilizing atomic force microscopy (AFM). Rats were randomly divided into three groups consisting of sham (n=6), global ischemia (GI, n=6), and MgSO4-treated global ischemia (MgSO4, n=6). The biophysical properties of brain mitochondria determined from AFM topographic images and adhesion force from force-distance measurements. The mean perimeter of ischemic mitochondria significantly increased to 2,396±541 nm (vs. 1,006±318 nm in control group, P<0.001). The MgSO4 treatment during global ischemia reduced the perimeter of ischemic mitochondria (1,127±399 nm, P<0.001). The other parameters including length, width and area were significantly different than the GI group. Besides, the adhesion force (23.2±3.9 nN) of isolated mitochondria from the MgSO4 group was close to normal levels (28.5±2.5 nN), compared with that of ischemic ones (17.7±3.3 nN, P<0.001). To confirm the neuroprotective effects of MgSO4, we performed Nissl staining. This study suggested that quantitative analysis of mitochondrial changes utilizing AFM could be effective for evaluating neuronal injury and drug effects.
线粒体在细胞存活中起核心作用，而凋亡性细胞死亡与线粒体的形态变化有关。对脑线粒体形态和力学性质变化进行定量分析，有助于评估缺血损伤程度以及各种药物的神经保护作用。本研究旨在利用原子力显微镜（AFM）研究硫酸镁（MgSO4）治疗的11血管闭塞缺血模型中脑线粒体的变化。将大鼠随机分为三组，即假手术组（n = 6）、全脑缺血组（GI，n = 6）和MgSO4治疗的全脑缺血组（MgSO4，n = 6）。通过AFM形貌图像确定脑线粒体的生物物理性质，并通过力-距离测量确定粘附力。缺血线粒体的平均周长显著增加至2396±541 nm（对照组为1006±318 nm，P<0.001）。全脑缺血期间MgSO4治疗可减小缺血线粒体的周长（1127±399 nm，P<0.001）。包括长度、宽度和面积在内的其他参数与GI组有显著差异。此外，与缺血线粒体的粘附力（17.7±3.3 nN，P<0.001）相比，MgSO4组分离线粒体的粘附力（23.2±3.9 nN）接近正常水平（28.5±2.5 nN）。为了证实MgSO4的神经保护作用，我们进行了尼氏染色。本研究表明，利用AFM对线粒体变化进行定量分析可有效评估神经元损伤和药物作用。
