Function of muscle lim protein (MLP) in neuroprotection and axon regeneration

肌肉 lim 蛋白 (MLP) 在神经保护和轴突再生中的作用

• 批准号: 278526477
• 负责人: Professor Dr. Dietmar Fischer
• 金额: --
• 依托单位: Zentrum für Pharmakologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/278526477?language=en
• 关键词: Function; muscle; lim; protein; MLP

As typical CNS neurons, retinal ganglion cells (RGCs) do not normally regenerate axons in the injured optic nerve and instead undergo apoptosis. However, inflammatory stimulation (IS) in the inner eye, induced by lens injury, is strongly neuroprotective and transforms RGCs into an active regenerative state, enabling them to regrow axons into the injured optic nerve. Based on a microarray study we identified genes differentially expressed in regenerating (induced by IS) vs. solely axotomized and naïve RGCs, one of which was muscle LIM protein (MLP). MLP has been postulated to be muscle-specific (skeletal muscle, but mainly heart) and involved in myogenesis without any known expression in the adult mammalian CNS. Using Western blot analysis and immunohistochemistry, we found profound induction of MLP protein in the cytosol (including nuclei) and axonal growth cones of mature RGCs upon optic nerve injury. Expression was further enhanced when RGCs entered a regenerative state after additional IS. Moreover, we detected MLP in a subpopulation of dorsal root ganglion (DRG) neurons upon sciatic nerve injury. Inhibition of MLP expression by short hairpin RNA (shRNA) compromised neurite growth of cultured RGCs and preliminary data demonstrate that overexpression of MLP further pro-motes IS-induced axon regeneration in the crushed optic nerve. In this proposed research project, we will (i) investigate the role of MLP in neuroprotection of axotomized RGCs, optic nerve as well as spinal cord regeneration, (ii) we will identify the underlying molecular mechanisms by testing the hypothesis that nuclear MLP might regulate gene expression after axon injury and (iii) by identification of functional relevant neuronal interaction partners and downstream signaling cascades of MLP. These experiments will identify the molecular mechanisms underlying the yet unknown role of MLP in CNS axon regeneration and might open novel approaches for CNS repair.

作为典型的CNS神经元，视网膜神经节细胞（RGC）通常不会在受伤的视神经中再生轴突，而是会发生凋亡。然而，由晶状体损伤诱导的内眼炎性刺激（IS）是强烈的神经保护性，并将RGC转化为活性再生状态，使它们能够将轴突重新生成受伤的视神经。基于一项微阵列研究，我们确定了在再生（由IS诱导的）与仅轴突和幼稚的RGC中不同表达的基因，其中一个是肌肉lim蛋白（MLP）。 MLP被认为是肌肉特异性的（骨骼肌，但主要是心脏），并参与了成年哺乳动物CNS中没有任何已知表达的肌发生。使用蛋白质印迹分析和免疫组织化学，我们发现了在视神经损伤后，成熟RGC的细胞质（包括核）和轴突生长锥中MLP蛋白的深刻诱导。当RGC在附加IS之后进入再生状态时，表达进一步增强。此外，我们在坐骨神经损伤后的背根神经元（DRG）神经元的亚群中检测到MLP。短发夹RNA（SHRNA）抑制MLP表达的抑制培养的RGC的神经蛋白神经蛋白的生长和初步数据表明，MLP的过表达进一步促进肌动物诱导的轴突再生在碎神经中诱导的轴突再生。在该提出的研究项目中，我们将（i）研究MLP在轴局能RGC，视神经和脊髓再生中的神经保护中的作用，（ii）我们将通过测试核MLP在轴突受伤和（iii II III）中的基因表达的假设来确定基本的分子机制，并通过轴突损伤和（iii）进行均匀的（iii）均具有相关性的构成性，并（IIIII）均具有相关性的兼容性，III均可及其均具有功能性的兼容性兼容性。 MLP。这些实验将确定MLP在CNS轴突再生中尚未知道的作用的分子机制，并可能打开CNS修复的新方法。