Cellular Models for Studying Alexander Disease: Functional Analysis of Primary Rat Astrocytes.

Astrocytes play a vital role in maintaining central nervous system homeostasis, supporting neuronal function, and responding to injury or disease. Dysfunction in astrocyte activity is increasingly recognized as a key contributor to neurodegenerative disorders, including Alexander disease (AxD), a rare and fatal condition caused by mutations in glial fibrillary acidic protein (GFAP). These mutations result in GFAP aggregation, Rosenthal fiber formation, and progressive astrocyte dysfunction. While in vivo animal models offer a complex cellular environment, both current in vitro and in vivo models face limitations in accurately replicating the intricate cellular context and functions of astrocytes. To address this, we developed a cellular model using primary rat astrocytes derived from wild-type (WT) and AxD model rats to study the functional effects of GFAP mutations. This physiologically relevant system enables detailed investigation of astrocyte-specific mechanisms, including GFAP aggregation, oxidative stress responses, and pathological modifications. For researchers without access to AxD model rats, lentiviral transduction offers an alternative method to introduce AxD-associated GFAP mutations into astrocytes derived from normal rats, thereby broadening the applicability of this approach. Compared with immortalized astrocyte cell lines or in vitro studies using recombinant protein, primary astrocytes better preserve native cellular architecture and molecular profiles, offering a robust platform for studying GFAP dynamics, solubility, and astrocytic responses to stressors such as oxidative damage and pathological modifications. This cellular model bridges the gap between molecular and systemic studies, providing a controlled experimental framework to explore astrocyte dysfunction in AxD. By complementing existing methodologies, primary astrocyte cultures enhance our understanding of AxD pathology and represent a valuable tool for identifying potential therapeutic targets for neurodegenerative diseases.