FKRP Expression System Tissue-Specific Regulation

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Solution Overview

Problem

Current gene therapy approaches for FKRP-related disorders, such as Limb-Girdle Muscular Dystrophy type 2I, face challenges due to potential cardiac toxicity associated with high-level FKRP expression in the heart, necessitating a safe and efficient expression system that modulates FKRP expression to avoid cardiac complications while maintaining therapeutic efficacy in skeletal muscles.

Innovation Solution

An expression system comprising a sequence encoding FKRP, regulated by a promoter sequence that ensures therapeutically acceptable levels in skeletal muscles and toxically acceptable levels in the heart, utilizing miRNA target sequences like miR208a to reduce FKRP expression in the heart, thereby minimizing cardiac toxicity while maintaining muscle tissue expression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high-level FKRP expression is achieved in the heart to treat cardiac abnormalities, then therapeutic efficacy is improved, but cardiac toxicity occurs

Engineering Contradiction:

Improvetherapeutic efficacyVSAvoidcardiac toxicity

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by making FKRP expression tissue-specific: high expression in skeletal muscles (therapeutic target) versus low expression in the heart (toxicity avoidance). This is achieved through tissue-specific promoters and miRNA target sequences that differentially regulate FKRP expression in different tissues, allowing the same protein therapy to have beneficial effects in one tissue while avoiding harmful effects in another.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If FKRP expression is modulated to reduce cardiac toxicity, then safety is improved, but therapeutic efficacy in skeletal muscles may be compromised

Engineering Contradiction:

Improvecardiac toxicityVSAvoidtherapeutic efficacy

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent uses miRNA target sequences as intermediaries to mediate differential regulation of FKRP expression. These miRNA binding sites in the 3'UTR region act as molecular switches that are recognized by tissue-specific miRNAs (such as miR-1, miR-133, miR-208), thereby enabling selective suppression of FKRP expression in cardiac tissue while preserving expression in skeletal muscles through the interplay between promoter activity and miRNA-mediated repression.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS20230270885A2Gene therapy expression system alleviating cardiac toxicity of fkrp

Publication Date: 2023.08.31 GENETHON

AI summary

The present invention concerns an expression system for systemic administration comprising a sequence encoding a FKRP protein, and:a promoter sequence allowing the expression at a therapeutically acceptable level of FKRP in the skeletal muscles and a target sequence of an miRNA expressed in the heart; ora promoter sequence allowing the expression at a therapeutically acceptable level of FKRP in the skeletal muscles and presenting a promoter activity at a toxically acceptable level in the heart;and its use for the treatment of various diseases linked to FKRP deficiencies.