Faculty Collaboration Database

Optimization of a 40-mer Antimyelin DNA Aptamer Identifies a 20-mer with Enhanced Properties for Potential Multiple Sclerosis Therapy. Nucleic Acid Ther 2019 Jun;29(3):126-135

Date

03/12/2019

Pubmed ID

30855209

Pubmed Central ID

PMC6555174

DOI

10.1089/nat.2018.0776

Scopus ID

2-s2.0-85066628371 (requires institutional sign-in at Scopus site)   17 Citations

Abstract

We previously reported the in vitro selection and characterization of a DNA aptamer capable of stimulating remyelination in a mouse model of multiple sclerosis. This aptamer was selected for its ability to bind to suspensions of crude murine myelin in vitro. Our initial studies in vitro and in vivo involved a 40-nucleotide derivative (LJM-3064) of the original 100-nucleotide aptamer. LJM-3064 retained robust myelin-binding properties. Structural characterization of LJM-3064 revealed that the guanosine-rich 5' half of the sequence forms different G-quadruplex-type structures that are variably stable in the presence of physiologically relevant ions. We hypothesized that this structured domain is sufficient for myelin binding. In this study, we confirm that a 20-nucleotide DNA, corresponding to the 5' half of LJM-3064, retains myelin-binding properties. We then optimize this minimal myelin-binding aptamer via systematic evolution of ligands by exponential enrichment after sparse rerandomization. We report a sequence variant (LJM-5708) of the 20-nucleotide myelin-binding aptamer with enhanced myelin-binding properties and the ability to bind cultured human oligodendroglioma cells in vitro, providing the first evidence of cross-species reactivity of this myelin-binding aptamer. As our formulation of DNA aptamers for in vivo remyelination therapy involves conjugation to streptavidin, we verified that the myelin-binding properties of LJM-5708 were retained in conjugates to avidin, streptavidin, and neutravidin. DNA aptamer LJM-5708 is a lead for further preclinical development of remyelinating aptamer technologies.

Author List

Wilbanks B, Smestad J, Heider RM, Warrington AE, Rodriguez M, Maher LJ 3rd

Author

John Smestad PhD, BS, MD Assistant Professor in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Aptamers, Nucleotide
Circular Dichroism
G-Quadruplexes
Humans
Mice
Multiple Sclerosis
Myelin Sheath
Oligodendroglioma
Protein Binding
SELEX Aptamer Technique
Streptavidin