cn7b00211_si_001.pdf (150.75 kB)
Chemically Modified, α‑Amino-3-hydroxy-5-methyl-4-isoxazole (AMPA) Receptor RNA Aptamers Designed for in Vivo Use
journal contribution
posted on 2017-09-05, 18:18 authored by Zhen Huang, Wei Wen, Andrew Wu, Li NiuGlutamate
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 GluA2Qflip 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.