Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA.
Mol Aspects Med. 2018 Dec;64:18-33. doi: 10.1016/j.mam.2018.09.003. Epub 2018 Oct 1.
The functional significance of the selective enrichment of the omega-3 essential fatty acid docosahexaenoic acid (DHA; 22C and 6 double bonds) in cellular membrane phospholipids of the nervous system is being clarified by defining its specific roles on membrane protein function and by the uncovering of the bioactive mediators, docosanoids and elovanoids (ELVs). Here, we describe the preferential uptake and DHA metabolism in photoreceptors and brain as well as the significance of the Adiponectin receptor 1 in DHA retention and photoreceptor cell (PRC) survival. We now know that this integral membrane protein is engaged in DHA retention as a necessary event for the function of PRCs and retinal pigment epithelial (RPE) cells. We present an overview of how a) NPD1 selectively mediates preconditioning rescue of RPE and PR cells; b) NPD1 restores aberrant neuronal networks in experimental epileptogenesis; c) the decreased ability to biosynthesize NPD1 in memory hippocampal areas of early stages of Alzheimer's disease takes place; d) NPD1 protection of dopaminergic circuits in an in vitro model using neurotoxins; and e) bioactivity elicited by DHA and NPD1 activate a neuroprotective gene-expression program that includes the expression of Bcl-2 family members affected by Aβ42, DHA, or NPD1. In addition, we highlight ELOVL4 (ELOngation of Very Long chain fatty acids-4), specifically the neurological and ophthalmological consequences of its mutations, and their role in providing precursors for the biosynthesis of ELVs. Then we outline evidence of ELVs ability to protect RPE cells, which sustain PRC integrity. In the last section, we present a summary of the protective bioactivity of docosanoids and ELVs in experimental ischemic stroke. The identification of early mechanisms of neural cell survival mediated by DHA-synthesized ELVs and docosanoids contributes to the understanding of cell function, pro-homeostatic cellular modulation, inflammatory responses, and innate immunity, opening avenues for prevention and therapeutic applications in neurotrauma, stroke and neurodegenerative diseases.
神经细胞膜磷脂中 ω-3 必需脂肪酸二十二碳六烯酸(DHA;22 个碳和 6 个双键)的选择性富集的功能意义,正在通过定义其对膜蛋白功能的特定作用以及揭示生物活性介质二十二碳六烯酸和 ELV(ELVs)来阐明。在这里,我们描述了光感受器和大脑中 DHA 的优先摄取和代谢,以及脂联素受体 1 在 DHA 保留和光感受器细胞(PRC)存活中的意义。我们现在知道,这种完整的膜蛋白参与 DHA 的保留,这是 PRC 和视网膜色素上皮(RPE)细胞功能所必需的事件。我们介绍了以下内容的概述:a)NPD1 如何选择性地介导 RPE 和 PR 细胞的预处理挽救;b)NPD1 如何恢复实验性癫痫发生中的异常神经元网络;c)阿尔茨海默病早期阶段海马记忆区中 NPD1 生物合成能力下降的情况;d)NPD1 如何在使用神经毒素的体外模型中保护多巴胺能回路;e)DHA 和 NPD1 引发的生物活性激活神经保护基因表达程序,包括受 Aβ42、DHA 或 NPD1 影响的 Bcl-2 家族成员的表达。此外,我们强调了 ELOVL4(长链脂肪酸延长酶 4),特别是其突变的神经学和眼科学后果及其在为 ELV 生物合成提供前体方面的作用。然后,我们概述了 ELV 保护 RPE 细胞的能力的证据,这些细胞维持 PRC 的完整性。在最后一节中,我们总结了二十二碳六烯酸和 ELV 在实验性缺血性中风中的保护生物活性。鉴定由 DHA 合成的 ELV 和二十二碳六烯酸介导的神经细胞存活的早期机制有助于理解细胞功能、原稳态细胞调节、炎症反应和先天免疫,为神经创伤、中风和神经退行性疾病的预防和治疗应用开辟了途径。