Contribution of iNOS for neurodegeneration in ALS and Parkinson's disease

为了研究诱导型一氧化氮合酶（iNOS）在肌萎缩性侧索硬化症（ALS）神经细胞变性中的作用，我们尝试将iNOS敲除（iNOS -/-）小鼠与突变型SOD1转基因（m SOD1 Tg/W）小鼠杂交。为此，我们从美国Jackson实验室购买了B6SJL-TgN(SOD1-G93A)1Gur菌株和B6.129P2-Nos2tm1Lau菌株。观察每只小鼠3代的运动功能、寿命和生育能力后，我们将雄性mSOD1 Tg/W小鼠与雌性iNOS -/-小鼠杂交。将成功生成的雄性mSOD1 Tg/W II iNOS +/-小鼠与雌性mSOD1 W/W II iNOS +/-小鼠进行再杂交。通过这些步骤，我们最终获得了基因不同的6组小鼠；mSOD1 Tg/W II iNOS -/-, mSOD1 Tg/W II iNOS +/-, mSOD1 Tg/W II iNOS +/+, mSOD1 W/W II iNOS -/-, mSOD1 W/W II iNOS +/-, mSOD1 W/W II iNOS +/+。每个基因型组随机选取8 ~ 12只小鼠，密切观察其运动功能，直至每只mSOD1 Tg/W小鼠无法进食和饮水。观察人员对小鼠的基因型进行了盲测。通过临床检查、体重、抓握力和在旋转杆上的剩余时间来评估运动功能。mSOD1 Tg/W II iNOS +/+与mSOD1 Tg/W II iNOS +/-、mSOD1 Tg/W II iNOS +/+与mSOD1 Tg/W II iNOS -/-之间存在显著差异；后两组运动功能恶化明显早于前两组。这些结果提示iNOS可能在m SOD1 Tg/W小鼠神经退行性变过程中发挥保护作用。

To investigate the roles of inducible nitric oxide synthase (iNOS) for neuronal cell degeneration in amyotrophic lateral sclerosis (ALS), we have attempted to cross iNOS knockout (iNOS -/-) mouse with mutant SOD1 transgenic (m SOD1 Tg/W) mouse. For this purpose, we purchased the B6SJL-TgN(SOD1-G93A)1Gur strain and the B6.129P2-Nos2tm1Lau strain from The Jackson Laboratory, USA. After observation of motor functions, life span, and fertility of each mouse for 3 generations, we crossed male mSOD1 Tg/W mice with female iNOS -/- mice. Successfully generated male mSOD1 Tg/W II iNOS +/- mice were re-crossed with female mSOD1 W/W II iNOS +/- mice. Through these procedures we finally obtained genetically different 6 groups of the mice; mSOD1 Tg/W II iNOS -/-, mSOD1 Tg/W II iNOS +/-, mSOD1 Tg/W II iNOS +/+, mSOD1 W/W II iNOS -/-, mSOD1 W/W II iNOS +/-, mSOD1 W/W II iNOS +/+. Eight to 12 mice from each genotype group were randomly selected and their motor functions were closely observed until the day when each mSOD1 Tg/W mouse was unable to eat and drink. The observers were blinded for genotypes of the mice. Motor functions were evaluated by clinical examination, by body weight, and by grasping power and the remaining time on the Rotarod. Significant differences were demonstrated between mSOD1 Tg/W II iNOS +/+ and mSOD1 Tg/W II iNOS +/-, and between mSOD1 Tg/W II iNOS +/+ and mSOD1 Tg/W II iNOS -/-; deterioration of motor function was significantly earlier in the latter 2 groups than the former one. These results imply that iNOS might play protective roles in processes of neurodegeneration in m SOD1 Tg/W mouse.