Evaluating exon skipping in the central nervous system in Duchenne muscular dystrophy using spatial transcriptomics

Area of Science:

• Neuroscience
• Genetics
• Molecular Biology

Background:

• Duchenne muscular dystrophy (DMD) involves dystrophin deficiency, impacting muscles and potentially the brain.
• Cognitive impairment affects one-third of DMD patients, but dystrophin expression in the brain is poorly understood.
• Lack of knowledge on brain dystrophin isoforms hinders therapeutic development for central nervous system (CNS) effects.

Purpose of the Study:

• To map dystrophin (Dmd) isoform expression across mouse brain regions and cell types.
• To evaluate the efficacy of exon-skipping therapy in restoring dystrophin isoforms in the CNS.
• To establish a framework for assessing CNS-targeted therapies for DMD using spatial transcriptomics.

Main Methods:

• Applied spatial transcriptomics to analyze Dmd isoform distribution in the mouse brain.
• Utilized mdx52 mouse model and exon 51-skipping therapy to restore dystrophin.
• Quantified transcript and protein levels of dystrophin isoforms post-treatment.

Main Results:

• Identified distinct spatial expression patterns for full-length and shorter dystrophin isoforms in the mouse brain.
• Confirmed restoration of the Dp427-sized dystrophin isoform in treated mdx52 mice.
• Observed immune activation following the exon-skipping therapy.

Conclusions:

• Spatial transcriptomics provides a powerful tool to characterize CNS dystrophin isoform expression.
• Exon-skipping therapy shows potential for restoring dystrophin in the brain, addressing cognitive deficits in DMD.
• Further research is warranted to fully understand and leverage dystrophin isoform restoration for treating DMD-associated neurological symptoms.