The COL6A5-p.Glu2272* mutation induces chronic itch in mice

Area of Science:

• Genetics
• Dermatology
• Neuroscience

Background:

• Chronic itch is a significant burden with complex causes.
• A specific Collagen VI alpha 5 (COL6A5) gene variant (p.Glu2272*) is linked to chronic neuropathic itch in patients.
• Reduced COL6A5 expression in skin was observed in affected patients.

Purpose of the Study:

• To develop and characterize the first mouse model for the COL6A5-p.Glu2272* mutation.
• To investigate the functional consequences of this mutation in vivo.
• To explore potential mechanisms linking COL6A5 to chronic itch.

Main Methods:

• CRISPR-Cas technology was used to create the COL6A5-p.Glu2272* mutant mouse model.
• RT-ddPCR was employed to measure mutant mRNA expression in dorsal root ganglia and skin.
• Phenotypic characterization included behavioral analysis (scratching, grooming, anxiety) and assessment of skin permeability.

Main Results:

• Mutant mice exhibited decreased COL6A5 mRNA levels in skin but normal levels in dorsal root ganglia.
• The mutation led to sex-specific dysmorphology and increased skin permeability.
• Mutant mice displayed elevated spontaneous scratching and grooming, with female mutants showing increased anxiety-like behavior.

Conclusions:

• The COL6A5-p.Glu2272* mutation contributes to chronic itch and associated behavioral changes in mice.
• This novel mouse model provides a valuable tool for elucidating the pathophysiology of COL6A5-related itch.
• The model may aid in identifying new therapeutic targets for chronic itch conditions.