A large-scale chemical screen for regulators of the arginase 1 promoter identifies the soy isoflavone daidzeinas a clinically approved small molecule that can promote neuronal protection or regeneration via a cAMP-independent pathway.
A large-scale chemical screen for regulators of the arginase 1 promoter identifies the soy isoflavone daidzeinas a clinically approved small molecule that can promote neuronal protection or regeneration via a cAMP-independent pathway.
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DOI：
10.1523/jneurosci.5266-09.2010
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发表时间：
2010-01-13
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影响因子：
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通讯作者：
Ratan RR
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作者：
Ma TC;Campana A;Lange PS;Lee HH;Banerjee K;Bryson JB;Mahishi L;Alam S;Giger RJ;Barnes S;Morris SM Jr;Willis DE;Twiss JL;Filbin MT;Ratan RR
中风或脊髓损伤的理想治疗应该促进CNS的存活和再生。精氨酸酶1（Arg1）已被证明可以保护运动神经元免受营养因子剥夺，并允许感觉神经元克服髓鞘蛋白对神经突生长的抑制。为了鉴定捕获Arg1的保护和再生特性的小分子，我们筛选了稳定表达与报告基因融合的Arg1基因的近端启动子区的海马细胞系，该细胞系针对含有临床批准药物的化合物库。该筛选确定大豆黄酮为Arg1的转录诱导物。在体外用大豆苷元引发的CNS和PNS神经元都克服了MAG对轴突生长的抑制，这反映在通过鞘内或皮下注射大豆苷元引发的体内急性分离和培养的感觉神经元上。此外，当眼内给予而无透镜损伤时，或者最重要的是，当在损伤后皮下给予时，大豆黄酮在视神经挤压模型中有效地促进轴突再生。从机制上讲，大豆苷元需要转录和诱导Arg1活性，以克服髓鞘抑制。与经典的Arg1激活剂相反，大豆黄酮增加Arg1而不增加CREB磷酸化，表明其作用是cAMP独立的。因此，它可以避免一些cAMP调节剂的已知CNS副作用。事实上，大豆黄酮似乎是安全的，因为它已被广泛用于豆制品中，穿过血脑屏障，并且在没有预处理的情况下有效，使其成为开发脊髓损伤或中风治疗的理想候选者。
An ideal therapeutic for stroke or spinal cord injury should promote survival and regeneration in the CNS. Arginase 1 (Arg1) has been shown to protect motor neurons from trophic factor deprivation and allow sensory neurons to overcome neurite outgrowth inhibition by myelin proteins. To identify small molecules that capture Arg1’s protective and regenerative properties, we screened a hippocampal cell line stably expressing the proximal promoter region of the arginase 1 gene fused to a reporter gene against a library of compounds containing clinically approved drugs. This screen identified daidzein as a transcriptional inducer of Arg1. Both CNS and PNS neurons primed in vitro with daidzein overcame neurite outgrowth inhibition from MAG, which was mirrored by acutely dissociated and cultured sensory neurons primed in vivo by intrathecal or subcutaneous daidzein infusion. Further, daidzein was effective in promoting axonal regeneration in vivo in an optic nerve crush model when given intraocularly without lens damage, or most importantly, when given subcutaneously after injury. Mechanistically, daidzein requires transcription and induction of Arg1 activity for its ability to overcome myelin inhibition. In contrast to canonical Arg1 activators, daidzein increases Arg1 without increasing CREB phosphorylation, suggesting its effects are cAMP-independent. Accordingly, it may circumvent known CNS side effects of some cAMP modulators. Indeed, daidzein appears to be safe as it has been widely consumed in soy products, crosses the blood-brain barrier, and is effective without pretreatment, making it an ideal candidate for development as a therapeutic for spinal cord injury or stroke.