ABE8e adenine base editor precisely and efficiently corrects a recurrent COL7A1 nonsense mutation

Area of Science:

• Genetics
• Molecular Biology
• Biotechnology

Background:

• Recessive dystrophic epidermolysis bullosa (RDEB) is a severe genetic blistering skin disease caused by COL7A1 gene mutations.
• Type VII collagen (C7) deficiency leads to skin fragility and blistering in RDEB patients.
• Base editing offers a potential therapeutic strategy for genetic diseases by precisely altering DNA sequences.

Purpose of the Study:

• To evaluate the efficacy and safety of ABE8e base editor for correcting the c.5047 C>T mutation in COL7A1.
• To assess the restoration of COL7A1 mRNA and C7 protein expression in RDEB patient fibroblasts.
• To investigate potential off-target editing effects of ABE8e in treated cells.

Main Methods:

• Utilized ABE8e adenine base editor mRNA for gene correction in primary RDEB patient fibroblasts.
• Employed next-generation sequencing to analyze editing efficiency and outcomes.
• Performed western blots and analyzed 3D skin constructs to confirm C7 protein restoration.
• Conducted off-target DNA and RNA analyses to assess safety.

Main Results:

• Achieved 94.6% efficiency in correcting the pathogenic COL7A1 allele in RDEB fibroblasts.
• Restored COL7A1 mRNA levels and functional C7 protein expression.
• No detectable off-target DNA edits or A-to-I RNA changes were observed.
• Demonstrated a favorable safety profile for the base editing approach.

Conclusions:

• Established a highly efficient gene correction pipeline for RDEB using ABE8e base editing.
• The ABE8e system shows promise for therapeutic applications in RDEB.
• This study provides a foundation for developing ex vivo and in vivo base editing strategies for RDEB patients.