Hall E D, Andrus P K, Oostveen J A, Fleck T J, Gurney M E
Central Nervous System Diseases Research, Pharmacia & Upjohn, Inc., Kalamazoo, Michigan, USA.
J Neurosci Res. 1998 Jul 1;53(1):66-77. doi: 10.1002/(SICI)1097-4547(19980701)53:1<66::AID-JNR7>3.0.CO;2-H.
Transgenic mice that overexpress a mutated human CuZn superoxide dismutase (SOD1) gene (gly93-->ala) found in some patients with familial ALS (FALS) have been shown to develop motor neuron disease, as evidenced by motor neuron loss in the lumbar and cervical spinal regions and a progressive loss of voluntary motor activity. The mutant Cu,Zn SOD exhibits essentially normal dismutase activity, but in addition, generates toxic oxygen radicals as a result of an enhancement of a normally minor peroxidase reaction. In view of the likelihood that the manifestation of motor neuron disease in the FALS transgenic mice involves an oxidative injury mechanism, the present study sought to examine the extent of lipid peroxidative damage in the spinal cords of the TgN(SOD1-G93A)G1H mice over their life span compared to nontransgenic littermates or transgenic mice that overexpress the wild-type human Cu,Zn SOD (TgN(SOD1)N29). Lipid peroxidation was investigated in terms of changes in vitamin E and malondialdehyde (MDA) levels measured by HPLC methods and by MDA-protein adduct immunoreactivity. Four ages were investigated: 30 days (pre-motor neuron pathology and clinical disease); 60 days (after initiation of pathology, but predisease); 100 days (approximately 50% loss of motor neurons and function); and 120 days (near complete hindlimb paralysis). Compared to nontransgenic mice, the TgN(SOD1-G93A)G1H mice showed blunted accumulation of spinal cord vitamin E and higher levels of MDA (P < 0.05 at 30 and 60 days) over the 30-120 day time span. In the TgN(SOD1)N29 mice, levels of MDA at age 120 days were significantly lower than in either the TgN(SOD1-G93A)G1H or nontransgenic mice. MDA-protein adduct immunoreactivity was also significantly increased in the lumbar spinal cord at age 30, 100, and 120 days, and in the cervical cord at 100 and 120 days. The results clearly demonstrate an increase in spinal cord lipid peroxidation in the FALS transgenic model, which precedes the onset of ultrastructural or clinical motor neuron disease. However, the greatest intensity of actual motor neuronal lipid peroxidative injury is associated with the active phase of disease progression. These findings further support a role of oxygen radical-mediated motor neuronal injury in the pathogenesis of FALS and the potential benefits of antioxidant therapy.
在一些家族性肌萎缩侧索硬化症（FALS）患者中发现的过表达突变型人类铜锌超氧化物歧化酶（SOD1）基因（gly93→ala）的转基因小鼠，已被证明会发展为运动神经元疾病，腰椎和颈脊髓区域的运动神经元损失以及自主运动活动的逐渐丧失证明了这一点。突变型铜锌超氧化物歧化酶表现出基本正常的歧化酶活性，但此外，由于正常情况下较弱的过氧化物酶反应增强，会产生有毒的氧自由基。鉴于FALS转基因小鼠中运动神经元疾病的表现可能涉及氧化损伤机制，本研究试图检查与非转基因同窝小鼠或过表达野生型人类铜锌超氧化物歧化酶的转基因小鼠（TgN(SOD1)N29）相比，TgN(SOD1-G93A)G1H小鼠在其整个生命周期中脊髓脂质过氧化损伤的程度。通过HPLC方法测量的维生素E和丙二醛（MDA）水平的变化以及MDA-蛋白质加合物免疫反应性来研究脂质过氧化。研究了四个年龄段：30天（运动神经元病理和临床疾病前期）；60天（病理开始后，但疾病前期）；100天（运动神经元和功能丧失约50%）；以及120天（后肢几乎完全瘫痪）。与非转基因小鼠相比，在30 - 120天的时间跨度内，TgN(SOD1-G93A)G1H小鼠脊髓维生素E的积累减少，MDA水平更高（30天和60天时P < 0.05）。在TgN(SOD1)N29小鼠中，120天时的MDA水平显著低于TgN(SOD1-G93A)G1H小鼠或非转基因小鼠。在30天、100天和120天时，腰脊髓中的MDA-蛋白质加合物免疫反应性也显著增加，在100天和120天时，颈脊髓中的MDA-蛋白质加合物免疫反应性也显著增加。结果清楚地表明，在超微结构或临床运动神经元疾病发作之前，FALS转基因模型中脊髓脂质过氧化增加。然而，实际运动神经元脂质过氧化损伤的最大强度与疾病进展的活跃期相关。这些发现进一步支持了氧自由基介导的运动神经元损伤在FALS发病机制中的作用以及抗氧化治疗的潜在益处。
