Sav1 shRNA for Cardiomyocyte Renewal in DMD Hearts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Duchenne Muscular Dystrophy (DMD) patients suffer from rapid skeletal and cardiac muscle degeneration, including myocardial necrosis and dilated cardiomyopathy, due to dystrophin gene mutations disrupting the dystrophin-associated glycoprotein complex, and existing therapies fail to effectively address cardiac conditions associated with this disorder.
Innovation Solution
Targeting the Hippo signaling pathway, specifically inhibiting Salvador (Sav1) using short hairpin RNA (shRNA) molecules, delivered via vectors such as AAV9, to modulate cardiomyocyte proliferation and regeneration, thereby treating cardiac conditions like DMD and heart failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing therapies are used for DMD, then skeletal muscle symptoms are partially addressed, but cardiac conditions deteriorate rapidly due to inability to promote cardiomyocyte renewal
Solution Approach 1:
The patent introduces shRNA molecules as intermediaries that specifically target and inhibit Sav1 protein, a key component of the Hippo signaling pathway. This intermediary approach blocks the pathway's inhibitory effect on cardiomyocyte proliferation, thereby promoting cardiac muscle renewal and improving cardiac function in DMD patients without directly addressing the underlying dystrophin deficiency.
Solution Approach 2:
The patent changes the molecular parameters of the Hippo signaling pathway by introducing shRNA that specifically reduces Sav1 expression levels. This parameter change (reducing Sav1) leads to downstream effects including reduced phosphorylation of Yap/Taz and increased nuclear translocation of these transcriptional co-activators, ultimately promoting cardiomyocyte proliferation and regeneration.
2Reliability
If Hippo pathway is inhibited to promote cardiomyocyte proliferation, then cardiac function improves, but off-target effects may occur due to pathway's role in other tissues
Solution Approach 1:
The patent employs cardiomyocyte-specific promoters (such as α-MHC or β-MHC promoters) to drive expression of shRNA molecules exclusively in cardiac muscle cells. This local quality approach ensures that Hippo pathway inhibition occurs only in cardiomyocytes where it is needed for regeneration, while sparing other tissues from potential off-target effects of pathway disruption.
Solution Approach 2:
The shRNA molecules serve as tissue-specific intermediaries that are expressed only in cardiomyocytes under the control of cardiac-specific promoters. This intermediary mechanism allows selective targeting of the Hippo pathway in cardiac tissue without affecting its function in other organs, thereby minimizing systemic off-target effects.
3Reliability
If shRNA therapy is delivered systemically, then cardiac tissue can be reached, but non-cardiac tissues are also affected causing unwanted side effects
Solution Approach 1:
The patent uses cardiomyocyte-specific promoters to ensure that shRNA expression is spatially restricted to cardiac muscle cells only. This local quality control mechanism allows systemic or local delivery of the therapeutic construct while ensuring that the therapeutic effect (Hippo pathway inhibition) occurs exclusively in cardiomyocytes, preventing unwanted effects in other tissues.
Solution Approach 2:
The patent employs inducible promoter systems that allow dynamic control of shRNA expression timing and level. This dynamic approach enables the therapy to be activated only when needed and to be turned off or reduced when therapeutic effect is achieved, providing temporal control that minimizes prolonged exposure and potential side effects in non-cardiac tissues.
Data Source
AI summary
Embodiments of the disclosure include methods and compositions for the renewal of cardiomyocytes by targeting the Hippo pathway. In particular embodiments, an individual with a need for cardiomyocyte renewal is provided an effective amount of a shRNA molecule that targets the Sav1 gene. Particular shRNA sequences are disclosed.