Department of Chemistry and Center for Neuroscience Research, University at Albany, SUNY , Albany, New York 12222, United States.
ACS Chem Neurosci. 2017 Nov 15;8(11):2437-2445. doi: 10.1021/acschemneuro.7b00211. Epub 2017 Sep 5.
Glutamate ion channels have three subtypes, that is, α-amino-3-hydroxy-5-methyl-4-isoxazole (AMPA), kainate, and N-methyl-d-aspartate (NMDA) receptors. Excessive activity of these receptor subtypes either individually or collectively is involved in various neurological disorders. RNA aptamers as antagonists of these receptors are potential therapeutics. For developing aptamer therapeutics, the RNA aptamers must be chemically modified to become ribonuclease-resistant or stable in biological fluids. Using systematic evolution of ligands by exponential enrichment (SELEX) and a chemically modified library, prepared enzymatically (i.e., the library contains RNAs with 2'-fluoro modified nucleoside triphosphates or ATPs, CTPs and UTPs, but regular GTPs), we have isolated an aptamer. The short aptamer (69 nucleotides) FN1040s selectively inhibits the GluA1 and GluA2Q AMPA receptor subunits, whereas the full-length aptamer (101 nucleotides) FN1040 additionally inhibits GluK1, but not GluK2, kainate receptor, and GluN1a/2A and GluN1a/2B, the two major native NMDA receptors. The two aptamers show similar potency (2-4 μM) and are stable with a half-life of at least 2 days in serum-containing medium or cerebrospinal fluid. Therefore, these two aptamers are amenable for in vivo use.
谷氨酸离子通道有三种亚型，即α-氨基-3-羟基-5-甲基-4-异恶唑（AMPA）、海人藻酸和 N-甲基-D-天冬氨酸（NMDA）受体。这些受体亚型的过度活动无论是单独还是集体参与各种神经疾病。作为这些受体的拮抗剂，RNA 适体是潜在的治疗药物。为了开发适体疗法，RNA 适体必须经过化学修饰，使其具有抗核酸酶性或在生物流体中稳定。使用指数富集配体系统进化（SELEX）和化学修饰文库（即文库中含有 2'-氟修饰核苷三磷酸或 ATP、CTP 和 UTP，但常规 GTP），我们分离出一种适体。短适体（69 个核苷酸）FN1040s 选择性抑制 GluA1 和 GluA2Q AMPA 受体亚基，而全长适体（101 个核苷酸）FN1040 还抑制 GluK1，但不抑制 GluK2、海人藻酸受体以及 GluN1a/2A 和 GluN1a/2B，这两种主要的天然 NMDA 受体。这两种适体具有相似的效力（2-4 μM），在含血清的培养基或脑脊液中至少稳定 2 天。因此，这两种适体适用于体内应用。
