Modified U7 snRNA Splicing Modulation for Neuromuscular Disease

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Solution Overview

Problem

Current RNA-based therapeutic strategies for neuromuscular diseases, such as Duchenne muscular dystrophy and myotonic dystrophy, face challenges in efficiently modulating splicing pathways and require repeated treatments, while existing exon skipping techniques using antisense oligonucleotides often fail to correctly interact with the splicing machinery.

Innovation Solution

A modified U7 snRNA is developed, incorporating a smOPT domain and an antisense sequence that interacts with the U7 loop, potentially enhanced by a 'kiss domain' to ensure correct folding and efficient targeting of the spliceosome, allowing for specific modulation of splicing events and treatment of neuromuscular diseases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional antisense oligonucleotides are used for exon skipping, then splicing modulation is attempted, but correct interaction with the splicing machinery is achieved poorly

Engineering Contradiction:
Improvesplicing modulation efficiencyVSAvoidmolecular structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses U7 snRNA as an intermediary molecule to mediate between the antisense sequence and the splicing machinery. The U7 snRNA structure includes a U7 loop that directly interacts with the spliceosome, while the antisense sequence targets the pre-mRNA, thereby improving the reliability of splicing modulation through a dual-function mediator structure

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention creates a composite molecular structure by combining the U7 snRNA scaffold with antisense sequences. This composite structure integrates the splicing machinery interaction capability of U7 snRNA with the target-specific binding capability of antisense sequences, achieving both structural stability and functional efficacy

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If RNA-based therapeutic strategies are used to modulate splicing pathways, then treatment of neuromuscular diseases is enabled, but repeated treatments are required

Engineering Contradiction:
Improvetherapeutic applicabilityVSAvoidtreatment duration
Core Design Contradiction:
Adaptability or versatilityVSDuration of action of moving object

Solution Approach 1:

The patent employs viral vectors to deliver the modified U7 snRNA construct into patient cells before the disease progresses significantly. The U7 snRNA is then expressed continuously from the integrated viral genome, establishing long-term splicing modulation that persists throughout the patient's life, eliminating the need for repeated treatments

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The modified U7 snRNA construct is designed to be self-sustaining within the patient's cells. Once delivered via viral vector, the construct uses the cell's own transcriptional machinery to produce functional U7 snRNA molecules continuously, creating a self-perpetuating therapeutic effect that maintains splicing correction without external intervention

Inventive Principle:
Principle #25Self-service

3Productivity

If exon skipping techniques are used to treat Duchenne muscular dystrophy, then dystrophin expression is attempted, but functional restoration is insufficient

Engineering Contradiction:
Improvedystrophin productionVSAvoidsplicing accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by designing the U7 snRNA with distinct functional domains: the U7 loop region is optimized for precise splice site recognition and interaction with the spliceosome, while the antisense sequence is customized to target specific exon regions. This localized functional specialization ensures both accurate splicing and efficient dystrophin production

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention optimizes multiple parameters of the U7 snRNA structure, including the length and sequence of the antisense region, the composition of the U7 loop, and the overall molecular architecture. These parameter optimizations enhance both the precision of splicing recognition and the efficiency of functional dystrophin protein production

Inventive Principle:
Principle #35Parameter changes

4Stability of the object's composition

If modified U7 snRNA with kiss domain is constructed, then correct folding is achieved, but off-target effects are reduced

Engineering Contradiction:
Improvemolecular folding accuracyVSAvoidoff-target effects
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The kiss domain acts as an intermediary structural element that mediates the correct folding of the U7 snRNA molecule. This domain facilitates proper spatial arrangement of the antisense sequence and U7 loop, ensuring high-specificity binding to the target pre-mRNA while preventing off-target interactions through accurate molecular geometry

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The modified U7 snRNA effectively promotes exon skipping, inclusion, or eradication of deleterious mRNAs, leading to functional restoration of proteins like dystrophin and SMN, with long-lasting effects and reduced off-target effects, improving splicing accuracy and muscle cell differentiation.

Implementation Method 1

An interaction between the antisense moiety and the U7 loop is required to obtain active U7-derived snRNPs

Methodology Applied
Scientific EffectHybridization:

Implementation Method 2

redirected to the spliceosome by replacement of the endogenous sm-binding domain with the one of the U1 snRNA

Methodology Applied
Scientific EffectMolecular recognition:

Data Source

PatentEP2547768B1Modified u7 snrnas for treatment of neuromuscular diseases
Publication Date: 2015.12.30 ASSOC INST DE MYOLOGIE
  • EP2547768B1 patent drawingFigure 1a~1d
  • EP2547768B1 patent drawingFigure 2a~2b
  • EP2547768B1 patent drawingFigure 2c

AI summary

The present invention relates to a method to improve the activity of engineered U7 snRNAs used in the context of RNA-based therapeutics; particularly in exon skipping, exon inclusion, and mRNA eradication strategies. The resulting modified U7 snRNAs are useful for treating neuromuscular diseases, in particular Duchenne neuromuscular dystrophy, myotonic dystrophy DM1 and spinal muscular atrophy.