COMPREHENSIVE CHARACTERIZATION OF PATIENT-DERIVED AND MURINE WOLFRAM SYNDROME MODELS TO ASSESS A NOVEL GENE THERAPY APPROACH

Wolfram syndrome (WS) is a rare autosomal recessive genetic disorder with multisystem involvement, affecting approximately 1 in 770,000 newborns. It is mainly caused by mutations in the WFS1 gene, which encodes wolframin, an endoplasmic reticulum transmembrane protein. The disease is characterized by diabetes insipidus, diabetes mellitus, optic nerve atrophy, and deafness. Currently, management is largely palliative, as there are no effective treatments. Gene therapy represents a promising approach for WS, as it may enable durable therapeutic benefit following a single administration. Here we generated two complementary in vitro models to evaluate a newly developed therapeutic strategy. First, patient-derived fibroblasts were reprogrammed into induced pluripotent stem cells (iPSCs) and differentiated into neurons and organoids. These 2D and 3D in vitro models are being analyzed to study disease-associated molecular mechanisms. Clear differences have been observed between patient and control lines, including mitochondrial dysfunction, neuronal clustering and altered connectivity, as well as changes in organoid size, sphericity, and wolframin levels, supporting their suitability for therapeutic testing. In parallel, an established Wfs1 KO mouse model enables in vivo evaluation of vector efficacy and safety. Longitudinal characterization revealed impaired locomotion and increased anxiety-like behavior in WS mice. Adeno-associated viral vectors are being developed to assess biodistribution through different administration routes, and using various isoforms of the endogenous WFS1 promoter driving the expression of a reporter gene. Overall, this strategy may lay the foundation for a unique treatment for this devastating disease.