Enhanced expression of the human Survival motor neuron 1 gene from a codon-optimised cDNA transgene in vitro and in vivo

Nafchi, Neda A M; Chilcott, Ellie M; Brown, Sharon; Fuller, Heidi R; Bowerman, Melissa; Yáñez-Muñoz, Rafael J

Abstract

Spinal muscular atrophy (SMA) is a neuromuscular disease particularly characterised by degeneration of ventral motor neurons. Survival motor neuron (SMN) 1 gene mutations cause SMA, and gene addition strategies to replace the faulty SMN1 copy are a therapeutic option. We have developed a novel, codon-optimised hSMN1 transgene and produced integration-proficient and integration-deficient lentiviral vectors with cytomegalovirus (CMV), human synapsin (hSYN) or human phosphoglycerate kinase (hPGK) promoters to determine the optimal expression cassette configuration. Integrating, CMV-driven and codon-optimised hSMN1 lentiviral vectors resulted in the highest production of functional SMN protein in vitro. Integration-deficient lentiviral vectors also led to significant expression of the optimised transgene and are expected to be safer than integrating vectors. Lentiviral delivery in culture led to activation of the DNA damage response, in particular elevating levels of phosphorylated ataxia telangiectasia mutated (pATM) and γH2AX, but the optimised hSMN1 transgene showed some protective effects. Neonatal delivery of adeno-associated viral vector (AAV9) vector encoding the optimised transgene to the Smn mouse model of SMA resulted in a significant increase of SMN protein levels in liver and spinal cord. This work shows the potential of a novel codon-optimised hSMN1 transgene as a therapeutic strategy for SMA. [Abstract copyright: © 2023. The Author(s), under exclusive licence to Springer Nature Limited.]

• Journal Article Type: Article
• Acceptance Date: May 4, 2023
• Online Publication Date: Jun 15, 2023
• Publication Date: Jun 15, 2023
• Deposit Date: Jul 4, 2023
• Publicly Available Date: Dec 16, 2023
• Journal: Gene Therapy
• Print ISSN: 0969-7128
• Electronic ISSN: 1476-5462
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1038/s41434-023-00406-0
• Keywords: DNA damage and repair, Gene expression, Gene expression analysis, Genetic vectors, Targeted gene repair
• Related Public URLs: https://pure.royalholloway.ac.uk/en/publications/enhanced-expression-of-the-human-survival-motor-neuron-1-gene-fro