Alexander disease (AxD) is an autosomal dominant neurodegenerative disorder caused by mutations in the gene encoding for the glial fibrillary acidic protein (GFAP), the major intermediate filament protein in astrocytes. In AxD patients, GFAP mutations are mainly clustered in hotspots affecting arginines of structural helical coiled-coil rod domains that play a crucial role in filament assembly. Mutated GFAP protein oligomerizes and accumulates within Rosenthal fibers, leading to astrocytic dysfunctions and altered development and homeostasis of affected brain tissues. AxD patients typically present with seizures, megalencephaly, spasticity, or developmental delays. Cerebral white matter abnormalities define this disorder as a demyelinating leukodystrophy. Antisense oligonucleotide (ASO)-mediated downregulation of total GFAP content showed therapeutic benefits in AxD animal models. Still, the high ASO doses required to achieve an acceptable level of GFAP knock-down pose some safety concerns in the chronic treatment of pediatric patients. Currently, this orphan disease (estimated incidence about 1 in 1 million births) lacks a cure.
The ASTRO-EDITING project aim to assess the efficacy of novel and definitive base/gene editing strategies targeting Gfap gene or Gfap hotspot mutations to recover pathological phenotypes in astrocytes. The project was developed in accordance with the following specific objectives:
Objective 1: selection of the best-performing editing system targeting the Gfap hotspot mutations or Gfap gene in an in vitro AxD model.
Objective 2: in vivo proof-of-concept studies on the efficiency and efficacy of the selected editing approach upon its AAV-mediated delivery in the central nervous system (CNS) of neonatal AxD mice.
ASTRO-EDITING provided in vitro and in vivo proof-of-concept data on the efficiency and efficacy of a novel AAV-based gene editing strategy that reduces GFAP content and pathological hallmarks in astrocytes. Additionally, the researcher's competences and knowledge in the gene therapy and neuroscience fields were reinforced thanks to the expertise of the host laboratory, the international environment of OSR, and scientific collaborations. The researcher created a new research niche, published scientific reviews, and improved his organizational, management and interpersonal skills, thus acquiring independence as experienced researcher in the scientific community.
