Development of the Treatment of Amyotrophic Lateral Sclerosis (ALS) with Neural Stem Cells

首先，我们检测了暴露于全身缺氧的G93A sod1突变小鼠血管内皮生长因子（VEGF）的诱导。与野生型小鼠相比，sod1突变小鼠的VEGF基线表达增加。缺氧几乎不诱导突变小鼠的VEGF表达，而野生型小鼠的VEGF表达增加了约9倍，这表明sod1突变小鼠的VEGF对缺氧的反应受损。接下来，我们研究了是否通过使用反义寡脱氧核苷酸（AS-ODNs）抑制Flk-1的表达来减少VEGF受体之一Flk-1，从而诱导运动神经元的损失。鞘内输注AS-ODNs 7天，几乎完全抑制了腰椎节段Flk-1的表达，随后进行1小时的缺氧刺激，重复7天。我们观察到，Flk-1表达降低和缺氧7天导致运动神经元损失约50%，其中Akt和ERK的激活，即缺氧导致磷酸化Akt和磷酸化ERK水平升高，明显受到抑制。这些结果提示VEGF通过Flk-1受体对运动神经元缺氧毒性发挥保护作用。为了研究IGF-1在家族性ALS小鼠模型中的可能有效性，我们将IGF-1连续注入脊髓鞘内间隙治疗G93A sod1突变小鼠。我们发现鞘内注射IGF-1可以改善G93A转基因小鼠的运动表现，延缓临床疾病的发作，延长生存期。接下来，我们进行了一项双盲临床试验，以评估鞘内给药IGF-1对ALS患者疾病进展的影响。我们发现鞘内给药IGF-1对ALS患者有适度但显著的有益作用，没有任何严重的不良反应。

At first, we examined the induction of vascular endothelial growth factor (VEGF) in the G93A SOD1-mutant mice exposed to systemic hypoxia. Baseline expression of VEGF was increased in the SOD1-mutant mice compared with wild-type littermates. VEGF expression in the mutant mice was hardly induced by hypoxia, in contrast to the wild-type littermates where approximately nine-fold increase in VEGF expression was observed, indicating that the response of VEGF to hypoxia is impaired in the SOD1-mutant mice. We next investigated whether reduction of Flk-1, one of VEGF receptors, could induce motor neuron loss by inhibiting the Flk-1 expression using antisense oligodeoxynucleotides (AS-ODNs). Intrathecal infusion of AS-ODNs for 7 days suppressed almost completely Flk-1 expression in the lumbar segment, and was followed by a hypoxic challenge for 1 hour that was repeated for 7 more days. We observed that reduced Flk-1 expression and hypoxic challenge for 7 days resulted in 〜50% loss of motor neurons, in which the activation of Akt and ERK, that is increased levels of phosphorylated-Akt and of phosphorylated-ERK by hypoxia, was markedly inhibited. These results suggest that VEGF exerts its protective effect on motor neurons against hypoxia-induced toxicity by the Flk-1 receptor.To examine the possible effectiveness of IGF-1 in a mouse model of familial ALS, the G93A SOD1-mutant mice were treated by continuous IGF-1 delivery into the intrathecal space of the lumbar spinal cord. We found that the intrathecal administration of IGF-1 improved motor performance, delayed the onset of clinical disease, and extended survival in the G93A transgenic mice. Next, we performed a double blind clinical trial to assess the effect of intrathecal administration of IGF-1 on disease progression in patients with ALS. We found that the intrathecal administration of IGF-1 had a modest but significant beneficial effect in ALS patients without any serious adverse effects.