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Biology subjects

Didier, N.

Publications and source records attributed to Didier, N..

2 recordsLinked to original sources

CRISPR/Cas13-mediated Dynamin 2 reduction therapy in a canine model of DNM2-related centronuclear myopathy

We determined the potential of CRISPR/Cas13 technology as a therapeutic approach for centronuclear myopathies (CNMs) by reducing the expression of a single protein, DNM2. CNMs are severe congenital rare muscle disorders that result in muscle hypotrophy and weakness, with no cure. CNMs frequently result from mutations in either BIN1, MTM1, or DNM2 genes, with DNM2 being a key GTPase that plays a pivotal role in muscle membrane interactions with MTM1 and BIN1. Previous studies indicate that reducing DNM2 transcript expression by half could correct CNM phenotypes regardless the genetic forms, paving the way for a broad-spectrum CNM-therapy. We evaluated CRISPR/Cas13X.1-mediated DNM2 transcript knockdown, as a therapeutic application in a unique naturally-occurring canine CNM model harboring the DNM2R465W/+ mutation, the most frequent pathogenic variant in patients. We show that in vivo intramuscular AAV-mediated CRISPR/Cas13X.1 injections, led to a reduction in DNM2 transcript and protein levels at one and two months post-treatment. Our results demonstrate the feasibility of CRISPR/Cas13-based therapy for CNM in a large animal model, paving the way for advancing this approach towards clinical trials.

molecular biology↗

Targeted-SMN insufficiency in Skeletal Muscle Stem Cells mediates non-cell autonomous loss of motor neurons at long term

Spinal Muscular Atrophy (SMA) is due to a deficit in SMN protein encoded by the SMN1 gene. SMN-targeted disease modifying treatments have greatly improved the clinical outcomes of this neuromuscular disease. However, uncertainties remain regarding their long-term efficacy and non-neuronal tissue involvement in disease progression. We found that SMA type II patient muscles display a reduced number of quiescent PAX7+ Muscle Stem Cells (MuSC). In SMA mice, we showed that SMN is an important regulator of myogenic progenitor fate during early postnatal growth. In Pax7 Cre-driven conditional knockout mouse models, we demonstrated that high levels of SMN are required to ensure the maintenance of the quiescent MuSC pool in adult muscle. We further established that depletion of SMN-deficient MuSC yielded neuromuscular junctions remodeling followed by a non-cell autonomous loss of motor neurons in the long term. Overall, our findings demonstrate that MuSC are a crucial therapeutic target for SMA treatment. HIGHLIGHTSO_LISMN regulates myogenic lineage progression and quiescent MuSC pool establishment during postnatal growth C_LIO_LIBoth Smn alleles are necessary for the survival of quiescent MuSC in adult muscle C_LIO_LIDepletion of SMN-deficient MuSC leads to NMJ remodeling and non-cell autonomous loss of MN C_LI

pathology↗