Antisense Compounds Modulate SMN2 Splicing for SMA Treatment
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Solution Overview
Problem
Proximal spinal muscular atrophy (SMA) is caused by the loss of both copies of the SMN1 gene, leading to a genetic disorder characterized by the degeneration of spinal motor neurons, with SMN2 gene transcripts lacking exon 7 being unstable and inactive, resulting in insufficient SMN protein production.
Innovation Solution
The use of antisense compounds targeting SMN-NAT to increase the expression of SMN2 and modulate its splicing to include exon 7, thereby enhancing the production of full-length SMN2 mRNA and increasing the levels of functional SMN protein.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If SMN2 gene is used to compensate for SMN1 loss, then SMN protein production is partially restored, but the transcripts lacking exon 7 are unstable and inactive, resulting in insufficient functional SMN protein
Solution Approach 1:
The invention uses antisense compounds to modify splicing parameters of SMN2 pre-mRNA, changing the inclusion/exclusion status of exon 7. By targeting specific splice sites with antisense oligonucleotides, the splicing pattern is altered to favor inclusion of exon 7, thereby converting unstable truncated transcripts into stable full-length functional SMN protein
Solution Approach 2:
Antisense compounds serve as intermediary molecules that bind to SMN2 pre-mRNA and modulate splicing. These compounds act as mediators between the SMN2 gene and the splicing machinery, directing the inclusion of exon 7 and thereby improving the stability and functionality of the resulting transcripts
2Productivity
If antisense compounds target SMN-NAT to increase SMN2 expression, then full-length SMN2 mRNA production is enhanced, but requires precise modulation of splicing to include exon 7
Solution Approach 1:
The invention divides the splicing modulation task into multiple targeted actions using different antisense compounds that bind to specific regions of SMN2 pre-mRNA. By segmenting the approach into distinct binding sites (e.g., exon 7 boundaries, splice donor/acceptor sites), the invention achieves precise control over splicing outcomes while increasing full-length mRNA production
Solution Approach 2:
The invention replaces the natural, imprecise splicing mechanism with a directed chemical approach using antisense compounds. Instead of relying on the inherent ambiguity of splice site selection, the antisense molecules provide chemical direction to the splicing machinery, ensuring accurate inclusion of exon 7 through molecular recognition and binding
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively increases the levels of functional SMN protein, potentially treating SMA by improving the stability and activity of SMN2 transcripts containing exon 7, addressing the genetic defect underlying the disease.
Implementation Method 1
The principle behind antisense technology is that an antisense compound, which hybridizes to a target nucleic acid, modulates gene expression activities such as transcription, splicing or translation
Data Source
AI summary
Certain embodiments are directed to methods and compounds for modulating expression of SMN. In certain embodiments at least two compounds are used: a first compound for inhibiting SMN-NAT and increasing expression of SMN, and a second compound for modulating the splicing of SMN. Such methods and compounds are useful for increasing expression exon 7 containing SMN mRNA in cells and animals.