SLC26A4 Enhancer-Promoter Control for Targeted Inner Ear Gene Expression
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Solution Overview
Problem
There is currently no curative therapy for hearing loss caused by mutations in the SLC26A4 gene, which affects the expression of Pendrin and leads to conditions like sensorineural hearing loss, Meniere's disease, and vestibular dysfunction.
Innovation Solution
The use of SLC26A4 promoters and enhancers operably linked to a polynucleotide to induce expression of proteins or RNA molecules in SLC26A4-expressing cells, delivered via nucleic acid vectors to treat or prevent hearing loss and vestibular dysfunction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional promoters are used to drive gene expression in inner ear cells, then expression levels may be high, but expression occurs in non-specific cell types including cells that do not endogenously express SLC26A4
Solution Approach 1:
The patent applies local quality by replacing the conventional promoter with an SLC26A4 enhancer element that provides localized, cell-type-specific regulation. The enhancer is positioned upstream of a minimal promoter to drive expression specifically in SLC26A4-expressing cells (such as inner ear supporting cells and thyroid follicular cells) while preventing expression in non-target cells. This resolves the contradiction by making the expression pattern match the endogenous SLC26A4 expression profile rather than using a constitutive promoter that would drive expression in all cell types.
2Reliability
If gene therapy is administered to treat SLC26A4-related hearing loss, then hearing function may be restored, but off-target expression in non-SLC26A4-expressing cells causes adverse effects
Solution Approach 1:
The patent uses the SLC26A4 enhancer to confer local quality control on gene expression, restricting therapeutic protein production to only those cells that endogenously express SLC26A4. This prevents off-target expression in non-relevant cells (such as hair cells or other inner ear cell types that do not normally express SLC26A4), thereby eliminating the harmful side effects while maintaining therapeutic efficacy in the target cells where the protein is needed.
Solution Approach 2:
The SLC26A4 enhancer acts as an intermediary element between the therapeutic gene and the cell type-specific expression pattern. Instead of directly controlling expression through a constitutive promoter, the enhancer mediates the expression to match the endogenous SLC26A4 pattern, serving as a regulatory bridge that ensures therapeutic proteins are produced only in the appropriate cell types and prevents harmful off-target effects.
Data Source
AI summary
The disclosure provides SL26A4 enhancers and SLC26A4 promoters, as well as vectors containing the same, that can increase gene expression in SLC26A4-expressing cells, such as interdental cells, root cells, spiral prominence cells, and vestibular supporting cells. The SLC26A4 enhancers and SLC26A4 promoters described herein may be operably linked to a polynucleotide, such as a transgene, encoding an expression product and used for the treatment of subjects having or at risk of developing hearing loss or vestibular dysfunction.