The Antisense Transcript SMN-AS1 Regulates SMN Expression and Is a Novel Therapeutic Target for Spinal Muscular Atrophy

Constantin d'Ydewalle; Daniel M Ramos; Noah J Pyles; Shi-Yan Ng; Mariusz Gorz; Celeste M Pilato; Karen Ling; Lingling Kong; Amanda J Ward; Lee L Rubin; Frank Rigo; C Frank Bennett; Charlotte J Sumner

doi:10.1016/j.neuron.2016.11.033

The Antisense Transcript SMN-AS1 Regulates SMN Expression and Is a Novel Therapeutic Target for Spinal Muscular Atrophy

Neuron. 2017 Jan 4;93(1):66-79. doi: 10.1016/j.neuron.2016.11.033. Epub 2016 Dec 22.

Authors

Affiliations

¹ Department of Neurology, Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, MD 21205, USA.
² Department of Neuroscience, Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, MD 21205, USA.
³ Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA; Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA.
⁴ Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA.
⁵ Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, MA 02142, USA.
⁶ Department of Neurology, Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, MD 21205, USA; Department of Neuroscience, Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, MD 21205, USA. Electronic address: csumner1@jhmi.edu.

Abstract

The neuromuscular disorder spinal muscular atrophy (SMA), the most common inherited killer of infants, is caused by insufficient expression of survival motor neuron (SMN) protein. SMA therapeutics development efforts have focused on identifying strategies to increase SMN expression. We identified a long non-coding RNA (lncRNA) that arises from the antisense strand of SMN, SMN-AS1, which is enriched in neurons and transcriptionally represses SMN expression by recruiting the epigenetic Polycomb repressive complex-2. Targeted degradation of SMN-AS1 with antisense oligonucleotides (ASOs) increases SMN expression in patient-derived cells, cultured neurons, and the mouse central nervous system. SMN-AS1 ASOs delivered together with SMN2 splice-switching oligonucleotides additively increase SMN expression and improve survival of severe SMA mice. This study is the first proof of concept that targeting a lncRNA to transcriptionally activate SMN2 can be combined with SMN2 splicing modification to ameliorate SMA and demonstrates the promise of combinatorial ASOs for the treatment of neurogenetic disorders.

Keywords: SMA therapeutics; SMN; antisense oligonucleotides; long non-coding RNA; spinal muscular atrophy.

MeSH terms

Animals
Blotting, Western
Cells, Cultured
Cerebral Cortex / cytology
Chromatin Immunoprecipitation
Disease Models, Animal
Gene Expression Regulation*
Humans
Induced Pluripotent Stem Cells
Mice
Motor Neurons / metabolism*
Muscular Atrophy, Spinal / genetics*
Muscular Atrophy, Spinal / metabolism
Neurons / metabolism
Oligonucleotides, Antisense / pharmacology
Polycomb Repressive Complex 2 / metabolism
Promoter Regions, Genetic
RNA Splicing
RNA, Antisense / drug effects
RNA, Antisense / genetics*
RNA, Antisense / metabolism
RNA, Long Noncoding / drug effects
RNA, Long Noncoding / genetics*
RNA, Long Noncoding / metabolism
Real-Time Polymerase Chain Reaction
Survival of Motor Neuron 1 Protein / genetics*
Survival of Motor Neuron 1 Protein / metabolism
Survival of Motor Neuron 2 Protein / genetics*
Survival of Motor Neuron 2 Protein / metabolism

Substances

Oligonucleotides, Antisense
RNA, Antisense
RNA, Long Noncoding
SMN2 protein, mouse
Smn1 protein, mouse
Survival of Motor Neuron 1 Protein
Survival of Motor Neuron 2 Protein
Polycomb Repressive Complex 2

Abstract

MeSH terms

Substances

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