Cuomo Ornella, Viscardi Viviana, Brancaccio Paola, Anzilotti Serenella, Guida Natascia, Lombardi Giovanna, Formisano Luigi, Esposito Rodolfo, Vinciguerra Antonio, Campanile Mario, D 'Esposito Lucia, Annunziato Lucio, Pignataro Giuseppe
Division of Pharmacology, Department of Neuroscience, School of Medicine, University of Naples Federico II, Naples 80131, Italy.
Division of Pharmacology, Department of Neuroscience, School of Medicine, University of Naples Federico II, Naples 80131, Italy; International School of Advanced Studies, University of Camerino, Camerino, Italy.
Biomed Pharmacother. 2025 Sep;190:118401. doi: 10.1016/j.biopha.2025.118401. Epub 2025 Aug 1.
Over the last two decades, there has been an increasing interest in understanding the mechanisms underlying neurogenesis as potential neurorestorative strategy triggered by ischemic preconditioning (IPC). Among these mechanisms, neuronal calcium homeostasis plays a fundamental role in supporting neurogenesis. Since sodium/calcium exchangers NCX1 and NCX3 are key effectors of IPC-mediated neuroprotection, this study aimed to investigate their contribution to the activation and maintenance of endogenous neurogenesis induced by IPC. Specifically, in an adult rat model of ischemic preconditioning, we examined whether: (1) IPC+tMCAO modulates the neurogenesis through NCX1 and NCX3 activation in subventricular zone (SVZ) and in the ipsilateral striatum; (2) NCX1 and NCX3 silencing may modulate the expression of "immature" neurons expressing the transcriptional factor NeuroD1 in SVZ; (3) the effects of IPC+tMCAO on the two isoforms, NCX1 and NCX3, are mediated by the transcriptional factor NeuroD1 expressed by "immature" neurons; (4) NeuroD1 directly binds ncx promoter evaluated by luciferase assay. Our findings revealed that, in the SVZ, IPC+tMCAO enhances at the same time either the expression of the neurogenesis marker, NeuroD1, and the expression of NCX1 and NCX3. Furthermore, the silencing of both NCX1 or NCX3 not only abolished the protective effects of IPC+tMCAO, but also impaired neuroblast proliferation, as NeuroD1 upregulation was completely suppressed. More interestingly, NeuroD1 directly binds ncx1 promoter, thus increasing its expression. Collectively, these results demonstrated that the transcriptional factor NeuroD1 regulates IPC+tMCAO-induced neurogenesis in the subventricular zone and in striatum by activating sodium/calcium exchanger ncx1, but not ncx3, in ischemic rats.
在过去二十年中，人们越来越关注了解神经发生的潜在机制，将其作为缺血预处理（IPC）引发的潜在神经修复策略。在这些机制中，神经元钙稳态在支持神经发生方面起着重要作用。由于钠/钙交换体NCX1和NCX3是IPC介导的神经保护的关键效应器，本研究旨在探讨它们对IPC诱导的内源性神经发生的激活和维持的作用。具体而言，在成年大鼠缺血预处理模型中，我们研究了：（1）IPC+tMCAO是否通过激活脑室下区（SVZ）和同侧纹状体中的NCX1和NCX3来调节神经发生；（2）NCX1和NCX3基因沉默是否会调节SVZ中表达转录因子NeuroD1的“未成熟”神经元的表达；（3）IPC+tMCAO对两种异构体NCX1和NCX3的影响是否由“未成熟”神经元表达的转录因子NeuroD1介导；（4）通过荧光素酶测定评估NeuroD1是否直接结合ncx启动子。我们的研究结果表明，在SVZ中，IPC+tMCAO同时增强了神经发生标志物NeuroD1的表达以及NCX1和NCX3的表达。此外，NCX1或NCX3的基因沉默不仅消除了IPC+tMCAO的保护作用，还损害了神经母细胞的增殖，因为NeuroD1的上调被完全抑制。更有趣的是，NeuroD1直接结合ncx1启动子，从而增加其表达。总的来说，这些结果表明，转录因子NeuroD1通过激活缺血大鼠中的钠/钙交换体ncx1而非ncx3，来调节IPC+tMCAO诱导的脑室下区和纹状体中的神经发生。
