CONNECTION PROJECT

FRRB Project 1731651 - Chondroitin sulfate proteoglycan-4, secreted by a binding imbalance between SP1 and NF-kB on CHST11 gene, triggers sympathetic cardiac denervation in Duchenne Muscular Dystrophy

PROJECT SUMMARY

Duchenne muscular dystrophy (DMD) is a neuromuscular disorder characterized by degeneration of skeletal and cardiac muscles.

We have shown that cardiac sympathetic innervation in the dystrophic mouse model is greatly reduced due to the accumulation of extracellular matrix proteins, including the proteoglycan CSPG4, released by macrophages attracted by the inflammatory environment present in the dystrophic heart. Preliminary data also showed a marked downregulation of the transcription factor SP1 in dystrophic macrophages, proposing it as a major contributor to the molecular imbalance. Preliminary chromatin sequencing experiments identified chst11, an enzyme responsible for the release of proteoglycans into the extracellular matrix, as a putative target of SP1. Accordingly, we acted on the restoration of SP1 activity on the promoter of chst11 using CRISPR-dCas9 technology: our system is able to modulate chst11 expression resulting in a suppressive effect on cspg4 transcription.

We will validate our hypothesis through 3D bioprinting applications for neurocardiac junction construction in a dystrophic environment. In addition, we will develop CAR-T against CSPG4 for the treatment of dystrophic pigs that we developed as an advanced study model. The multifactorial therapeutic approach, which we propose, highlights the need for a multifocal intervention that identifies and corrects the complicated cause and effect relationships between different affected physiological systems, which in turn may decompensate additional downstream systems.

The resolution of the present project will pave the way for the development of new multisystem therapeutic approaches that will improve the life expectancy of DMD patients.