TFEB Family Multi-Target Activation for Synaptic Lysosomal Restoration in Alzheimer's Disease

This hypothesis proposes that coordinated activation of the entire TFEB family (TFEB, TFE3, TFE4) creates synergistic enhancement of lysosomal biogenesis specifically at synaptic terminals in Alzheimer’s disease. While previous approaches focused on single-target TFEB activation, the multi-target family approach leverages the distinct but overlapping transcriptional programs of TFE3 and TFE4, which show preferential expression in different neuronal subtypes and subcellular compartments. TFE3 exhibits enhanced synaptic localization and directly regulates presynaptic autophagy machinery, while TFE4 controls postsynaptic lysosomal positioning and cargo recognition. Simultaneous activation of all three family members through dual mTORC1/GSK3β inhibition will create complementary waves of lysosomal gene expression, targeting different aspects of the autophagy-lysosomal cascade. This coordinated response will establish robust clearance of amyloid-beta oligomers from synaptic clefts and tau aggregates from dendritic spines, addressing both presynaptic and postsynaptic pathology. The intervention targets the critical early-stage synaptic dysfunction that precedes neuronal death in Alzheimer’s disease. Evidence will be gathered through comprehensive longitudinal analysis using APP/PS1 and 3xTg-AD mouse models, employing advanced techniques including super-resolution microscopy of synaptic lysosomes, electrophysiological recordings of synaptic transmission, and proteomics analysis of synaptic fractions. Biomarker validation will utilize cerebrospinal fluid measurements of family-specific transcriptional targets and PET imaging to track real-time changes in brain amyloid burden. This multi-target approach addresses the cellular complexity of synaptic pathology while maintaining the fundamental waste management strategy.