MODELING NEURODEGENERATION THROUGH D-GALACTOSE-DRIVEN SENESCENCE IN HUMAN IPSCS-DERIVED BRAIN ORGANOIDS: A PROMISING PLATFORM FOR DRUG SCREENING

Human brain organoids provide a versatile three-dimensional in vitro platform to study neurodevelopmental and neurodegenerative processes. While they recapitulate key aspects of human brain development and cellular diversity, their relative developmental immaturity remains a limitation for modelling long-term aging and late-onset age-related pathologies in vitro. Consequently, accelerated aging paradigms are required to induce aging-associated phenotypes within experimentally accessible timeframes.
In this study, we applied a D-galactose–based aging model across both unguided cerebral organoids and guided dorsal forebrain organoids derived from healthy human iPSCs. D-galactose, a monosaccharide commonly used to induce aging-like phenotypes in animal models and neural cultures, was administered for seven days during a critical maturation window.
In cerebral organoids, D-galactose treatment induced a neurosenescent and pro-inflammatory molecular profile, characterized by transcriptional changes associated with oxidative stress, inflammation, and apoptotic signalling, supporting their suitability for investigating stress-related aging pathways. In parallel, dorsal forebrain organoids exhibited a distinct response pattern. Consistent with their enriched neural composition, these organoids showed attenuated activation of inflammation-related pathways. Nevertheless, D-galactose exposure resulted in a marked downregulation of synaptic and antioxidant markers, including PSD95, SYP, SOD2, and CAT, together with alterations in stress-related genes, indicating impaired synaptic integrity. Furthermore, mitochondrial functional analysis revealed that D-galactose significantly impaired mitochondrial respiratory capacity.
Overall, our findings demonstrate that D-galactose induces aging- and neurodegeneration-like features in both cerebral and dorsal forebrain organoids, with complementary phenotypic outputs. The use of these models provides a robust framework for studying neurosenescence-associated mechanisms and for screening neuroprotective and anti-aging strategies.