Galactosylceramidase (GALC) as a therapeutic target for multiple sclerosis

Overview

This research program investigates the role of galactosylceramidase (GALC), a lysosomal enzyme, in maintaining the stability of adult white matter and protecting it against inflammatory demyelination. Studies in a mouse model with GALC deficiency revealed that reduced enzyme activity in adult oligodendrocytes (the cells that produce myelin) leads to spontaneous inflammatory demyelination resembling multiple sclerosis (MS) plaques. These findings establish GALC as a promising therapeutic target and lay the groundwork for an adult brain gene therapy strategy aimed at preventing, halting, or reversing demyelination in MS patients.

Technical specifications

Key findings and approach:

• Gene therapy model: Twitcher mice (full GALC deficiency, normally fatal by 45 days) treated with early gene therapy survived into adulthood and developed focal inflammatory demyelination in brain white matter with reduced GALC activity
• Conditional ablation model: GALC floxed transgenic mice with tamoxifen-induced GALC silencing in adult oligodendrocytes (PLP+) showed significant reduction in GALC activity, increased CD68+ immune cell infiltration, elevated GFAP astrogliosis, and myelin degeneration in cerebellar white matter and corpus callosum (p<0.02)
• Future validation plans: Longitudinal analysis at 3, 6, and 9 months post-recombination; assessment of remyelination capacity; challenge with experimental autoimmune encephalomyelitis (EAE) model; and testing of adult brain gene therapy to reconstitute GALC activity

Technology readiness level

The research is at the preclinical stage, with hypothesis validation completed in two independent mouse models (gene therapy-treated twitcher mice and conditional GALC knockout mice). Statistical significance has been achieved for key pathological readouts. Remaining work includes longitudinal characterization, remyelination studies, EAE challenge experiments, and proof-of-concept gene therapy intervention in adult mice. Successful completion of these steps would establish the foundation for evaluating translation potential toward MS treatment.