Sonic Hedgehog is Cytoprotective against Oxidative Challenge in a Cellular Model of Amyotrophic Lateral Sclerosis
Sonic Hedgehog is Cytoprotective against Oxidative Challenge in a Cellular Model of Amyotrophic Lateral Sclerosis
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DOI：
10.1007/s12031-011-9660-x
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发表时间：
2012-05-01
影响因子：
3.1
通讯作者：
Turnbull, John
中科院分区：
文献类型：
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作者：
Peterson, Randy;Turnbull, John
我们以前已经证明，脊髓运动神经元上的初级纤毛减少G93A SOD 1（mSOD）小鼠，肌萎缩侧索硬化症（ALS）的小鼠模型。Sonic hedgehog（Shh）信号传导涉及初级纤毛，并且Shh已被证明在其他神经退行性疾病的模型中具有细胞保护作用。因此，Shh信号通路在ALS中的作用有待进一步研究。因此，我们建立了Shh通路的干扰（用Shh拮抗剂环巴胺或miRNA 3245p）致敏HT 22细胞，而Shh通路的增强（用Shh或Shh激动剂purmorphamine）保护细胞免受过氧化氢（H2O2）的攻击。我们异位表达mSOD，人野生型SOD 1（wtSOD），或在HT22细胞中的空载体。与空载体相比，wtSOD减少了H2O2攻击引起的细胞死亡，mSOD增加了H2O2攻击引起的细胞死亡。用环巴胺或miRNA 3245p处理使所有三种转染对H2O2攻击敏感。用重组人Shh或purmorphamine处理减少H2O2攻击后的细胞死亡，在mSOD细胞中的效果更明显。与空载体相比，wtSOD的过表达增加了Shh和Gli的转录水平，并在Gli响应报告分析中增加了活性。过表达的mSOD没有改变Shh转录水平，但降低Gli转录水平，特别是Gli3，并降低活性，在Gli报告分析。这些结果表明，mSOD而不是wtSOD的过表达减少了Shh通路中的信号传导，并使mSOD细胞对H2O2攻击更敏感，并且用Shh或Shh激动剂处理对mSOD细胞具有细胞保护作用。Shh或Shh激动剂值得进一步考虑作为ALS的潜在治疗。
We have previously demonstrated that primary cilia on spinal motor neurons are reduced in G93A SOD1 (mSOD) mice, a mouse model of amyotrophic lateral sclerosis (ALS). Sonic hedgehog (Shh) signaling involves the primary cilium and Shh has been shown to be cytoprotective in models of other neurodegenerative diseases. Thus, the Shh signaling pathway may bear further study in ALS. Accordingly, we established that interference with the Shh pathway (with the Shh antagonist cyclopamine or with miRNA 3245p) sensitized HT22 cells, while augmentation of the Shh pathway (with Shh or the Shh agonist purmorphamine) protected cells against hydrogen peroxide (H2O2) challenge. We ectopically expressed mSOD, human wild-type SOD1 (wtSOD), or an empty vector in HT22 cells. Compared to empty vector, wtSOD decreased cell death and mSOD increased cell death in response to H2O2 challenge. Treatment with cyclopamine or miRNA 3245p sensitized all three transfections to H2O2 challenge. Treatment with recombinant human Shh or purmorphamine decreased cell death after H2O2 challenge, an effect more pronounced in mSOD cells. Compared with empty vector, overexpression of wtSOD increased Shh and Gli transcript levels and increased activity in a Gli-responsive reporter assay. Overexpression of mSOD did not change Shh transcript levels, but decreased Gli transcript levels, especially Gli3, and reduced activity in a Gli reporter assay. These results suggest that overexpression of mSOD but not wtSOD reduces signaling in the Shh pathway and renders mSOD cells more susceptible to H2O2 challenge, and that treatment with Shh or Shh agonists is cytoprotective to mSOD cells. Shh or Shh agonists merit further consideration as potential therapy in ALS.