Project/Area Number |
14570598
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Neurology
|
Research Institution | Okayama University |
Principal Investigator |
NAGANO Isao Okayama University, Hospital, Instructor, 医学部・歯学部附属病院, 講師 (80335603)
|
Co-Investigator(Kenkyū-buntansha) |
ABE Koji Okayama University, Graduate School of Medicine and Dentistry, Professor, 大学院・医歯学総合研究科, 教授 (20212540)
HONMOU Osamu Sapporo Medical University, Instructor, 医学部, 講師 (90285007)
|
Project Period (FY) |
2002 – 2004
|
Project Status |
Completed (Fiscal Year 2004)
|
Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2004: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2003: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2002: ¥1,400,000 (Direct Cost: ¥1,400,000)
|
Keywords | ALS / SOD1 / VEGF / hypoxia / Flk-1 / IGF-1 / neural precursor cell / motor neuron / G93A / transgenic mouse / stem cell / PI3-K / Akt / ERK / Pl3-K / Ref-1 |
Research Abstract |
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.
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