MBNL1 and RNAi Vector Delivery With Tissue Detargeting for Myotonic Dystrophy
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Solution Overview
Problem
Current methods fail to effectively regulate and control the levels of factors contributing to myotonic dystrophy, such as DMPK, MBNL, CUGBP1, and CELF1, leading to cardiotoxicity and other organ damage, without addressing the underlying splicing abnormalities and RNA toxicity.
Innovation Solution
Compositions and methods involving nucleic acid constructs, including siRNA, miRNA, and shRNA, are used to suppress expanded repeat regions in RNA transcripts, combined with tissue-specific expression control using cardiac miRNA and chimeric introns to enhance MBNL1 expression, delivered via AAV vectors to treat myotonic dystrophy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If RNA interference vectors are used to suppress expanded repeat regions, then pathological RNA transcripts are reduced, but cardiotoxicity and organ damage occur
Solution Approach 1:
The patent applies tissue-specific promoters to enable selective expression of MBNL1 protein only in skeletal muscle tissue, avoiding expression in cardiac tissue. This local quality approach allows pathological RNA suppression in muscle while preventing cardiotoxicity through tissue-restricted delivery and expression.
Solution Approach 2:
The patent uses an intermediary protein (MBNL1) that mediates the therapeutic effect by binding to and suppressing expanded repeat RNA transcripts. This intermediary mechanism allows indirect action on the harmful RNA while avoiding direct toxicity to the heart, as the protein itself is non-toxic when delivered via AAV vectors with muscle-specific promoters.
2Reliability
If MBNL1 protein expression is increased to correct splicing abnormalities, then functional MBNL1 levels increase, but cardiotoxicity is caused
Solution Approach 1:
The patent employs tissue-specific promoters that drive MBNL1 expression exclusively in skeletal muscle cells, preventing expression in cardiac tissue. This local quality control ensures splicing correction occurs where needed (muscle) while avoiding the harmful effects (cardiotoxicity) that would result from systemic or cardiac expression.
Solution Approach 2:
The patent segments the therapeutic effect by delivering MBNL1 expression specifically to skeletal muscle tissue through tissue-specific promoters, separating the beneficial splicing correction function from the harmful cardiac effects. This segmentation allows independent optimization of muscle-specific therapy without compromising cardiac safety.
3Adaptability or versatility
If systemic delivery of therapeutic vectors is used, then treatment coverage is improved, but off-target effects and cardiotoxicity increase
Solution Approach 1:
The patent uses tissue-specific promoters to achieve local quality control, allowing systemic delivery of vectors while restricting MBNL1 expression to skeletal muscle tissue only. This approach maintains broad treatment coverage through systemic administration while preventing off-target effects in other organs through promoter-specificity.
Solution Approach 2:
The patent employs tissue-specific promoters as intermediary elements that control vector expression. These promoters act as molecular switches that activate MBNL1 expression only in muscle tissue upon systemic delivery, thereby maintaining treatment coverage while preventing off-target effects through intermediary control.
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 functional MBNL1 levels in cells, reduces pathological RNA transcripts, and minimizes cardiotoxicity by tissue-specific regulation, providing therapeutic benefits for myotonic dystrophy.
Implementation Method 1
Compositions and methods involving nucleic acid constructs, including siRNA, miRNA, and shRNA, are used to suppress expanded repeat regions in RNA transcripts
Implementation Method 2
delivered via AAV vectors to treat myotonic dystrophy
Implementation Method 3
tissue-specific expression control using cardiac miRNA and chimeric introns to enhance MBNL1 expression
Data Source
AI summary
The disclosure features compositions and methods for the treatment of trinucleotide repeat expansion disorders. The compositions described herein that may be used to treat such disorders include at least one nucleic acid construct comprising a first nucleic acid sequence. In some embodiments, the first nucleic acid sequence encodes a therapeutic protein. In some embodiments, the first nucleic acid sequence encodes a MBNL protein. In some embodiments, the first nucleic acid sequence encodes MBNL1 protein. The composition may comprise at least one nucleic acid construct comprising a second nucleic acid. In some embodiments, the second nucleic acid sequence encodes an interfering RNA construct that suppresses the expression of RNA transcripts containing aberrantly expanded repeat regions. Disclosed herein are also methods of increasing the presence of functional muscleblind-like protein (MBNL) in the nucleus of a cell with expression control in tissue types and methods of treating muscular dystrophy or spliceopathy using the compositions disclosed herein.