Gamir-Morralla A, López-Menéndez C, Ayuso-Dolado S, Tejeda G S, Montaner J, Rosell A, Iglesias T, Díaz-Guerra M
Department of Endocrine and Nervous System Physiopathology, Instituto de Investigaciones Biomédicas "Alberto Sols", Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid 28029, Spain.
CIBERNED, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Instituto de Salud Carlos III, Madrid, Spain.
Cell Death Dis. 2015 Oct 22;6(10):e1939. doi: 10.1038/cddis.2015.307.
Kinase D-interacting substrate of 220 kDa (Kidins220), also known as ankyrin repeat-rich membrane spanning (ARMS), has a central role in the coordination of receptor crosstalk and the integration of signaling pathways essential for neuronal differentiation, survival and function. This protein is a shared downstream effector for neurotrophin- and ephrin-receptors signaling that also interacts with the N-methyl-d-aspartate type of glutamate receptors (NMDARs). Failures in neurotrophic support and glutamate signaling are involved in pathologies related to excitotoxicity and/or neurodegeneration, where different components of these dynamic protein complexes result altered by a combination of mechanisms. In the case of Kidins220/ARMS, overactivation of NMDARs in excitotoxicity and cerebral ischemia triggers its downregulation, which contributes to neuronal death. This key role in neuronal life/death decisions encouraged us to investigate Kidins220/ARMS as a novel therapeutic target for neuroprotection. As the main mechanism of Kidins220/ARMS downregulation in excitotoxicity is proteolysis by calpain, we decided to develop cell-penetrating peptides (CPPs) that could result in neuroprotection by interference of this processing. To this aim, we first analyzed in detail Kidins220/ARMS cleavage produced in vitro and in vivo, identifying a major calpain processing site in its C-terminal region (between amino acids 1669 and 1670) within a sequence motif highly conserved in vertebrates. Then, we designed a 25-amino acids CPP (Tat-K) containing a short Kidins220/ARMS sequence enclosing the identified calpain site (amino acids 1668-1681) fused to the HIV-1 Tat protein basic domain, able to confer membrane permeability to attached cargoes. Transduction of cortical neurons with Tat-K reduced Kidins220/ARMS calpain processing in a dose- and time-dependent manner upon excitotoxic damage and allowed preservation of the activity of pERK1/2 and pCREB, signaling molecules central to neuronal survival and functioning. Importantly, these effects were associated to a significant increase in neuronal viability. This Kidins220/ARMS-derived peptide merits further research to develop novel neuroprotective therapies for excitotoxicity-associated pathologies.
220 kDa的激酶D相互作用底物（Kidins220），也被称为富含锚蛋白重复序列的跨膜蛋白（ARMS），在协调受体串扰以及整合对神经元分化、存活和功能至关重要的信号通路中发挥核心作用。该蛋白是神经营养因子受体和ephrin受体信号传导的共同下游效应器，还与N-甲基-D-天冬氨酸型谷氨酸受体（NMDARs）相互作用。神经营养支持和谷氨酸信号传导的失败与兴奋性毒性和/或神经退行性变相关的病理过程有关，在这些病理过程中，这些动态蛋白复合物的不同组分由于多种机制的组合而发生改变。就Kidins220/ARMS而言，兴奋性毒性和脑缺血中NMDARs的过度激活会触发其下调，这会导致神经元死亡。其在神经元生死抉择中的这一关键作用促使我们将Kidins220/ARMS作为神经保护的新型治疗靶点进行研究。由于在兴奋性毒性中Kidins220/ARMS下调的主要机制是钙蛋白酶的蛋白水解作用，我们决定开发能够通过干扰这一过程而实现神经保护的细胞穿透肽（CPPs）。为此，我们首先详细分析了体外和体内产生的Kidins220/ARMS裂解情况，在其C末端区域（氨基酸1669和167０之间）的一个脊椎动物中高度保守的序列基序内确定了一个主要的钙蛋白酶加工位点。然后，我们设计了一种25个氨基酸的CPP（Tat-K），它包含一段围绕已确定的钙蛋白酶位点（氨基酸1668 - 1681）的短Kidins220/ARMS序列，并与HIV-1 Tat蛋白的碱性结构域融合，能够赋予附着的货物膜通透性。用Tat-K转导皮质神经元可在兴奋性毒性损伤后以剂量和时间依赖性方式减少Kidins220/ARMS的钙蛋白酶加工，并能保留pERK1/2和pCREB的活性，这两种信号分子对神经元的存活和功能至关重要。重要的是，这些效应与神经元活力的显著增加相关。这种源自Kidins220/ARMS的肽值得进一步研究，以开发针对兴奋性毒性相关病症的新型神经保护疗法。
Zotero 插件
