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Article published by Dr. Astrid Brull
Below we leave you the article published by Dr. Astrid Brull, Member of the NINDS-NIH (USA) Research team, in the American Society of Gene & Cell Therapy with the title “Optimized allele-specific silencing of the dominant-negative COL6A1 G293R substitution causing collagen VI-related dystrophy”.
Introduction to the article:
Collagen VI-related dystrophies (COL6-RDs) are a group of severe, congenital-onset muscular dystrophies for which there is no effective causative treatment. Dominant-negative mutations are common in COL6A1, COL6A2, and COL6A3 genes, encoding the collagen a1, a2, and a3 (VI) chains. They act by incorporating into the hierarchical assembly of the three a (VI) chains and consequently produce a dysfunctional collagen VI extracellular matrix, while haploinsufficiency for any of the COL6 genes is not associated with disease. Hence, allele-specific transcript inactivation is a valid therapeutic strategy, although selectively targeting a pathogenic single nucleotide variant is challenging. Here, we develop a small interfering RNA (siRNA) that robustly, and in an allele-specific manner, silences a common glycine substitution (G293R) caused by a single nucleotide change in COL6A1 gene. By intentionally introducing an additional mismatch into the siRNA design, we achieved enhanced specificity toward the mutant allele. Treatment of patientderived fibroblasts effectively reduced the levels of mutant transcripts while maintaining unaltered wild-type transcript levels, rescuing the secretion and assembly of collagen VI matrix by reducing the dominant-negative effect of mutant chains. Our findings establish a promising treatment approach for patients with the recurrent dominantly negative acting G293R glycine substitution.