MicroEatAD · Restoring microglial lysosomal capacity in neurodegeneration

Alzheimer’s disease (AD) is the most common cause of dementia, affecting over 57 million people worldwide. It is a progressive, fatal neurodegenerative disorder with no curative treatments, imposing a major burden on patients, families, healthcare systems, and society.AD is marked by amyloid-beta (Aβ) plaque accumulation. Microglia, the brain’s immune cells, attempt to degrade these aggregates through their lysosomes, but this process is often inefficient and may even contribute to Aβ spread. I hypothesize that Aβ pathology reshapes the proteome of human microglial lysosomes, impairing their function and promoting disease progression. To date, no study has systematically mapped how the human microglial lysosomal proteome changes dynamically in response to Aβ pathology. To address this knowledge gap, I will use a xenotransplantation model in which human iPSC-derived microglia are engrafted into either healthy or Aβ-accumulating mouse brains. TurboID proximity labeling will enable in vivo profiling of lysosomal proteins altered by Aβ pathology. To test the functional consequences of this alteration, I will employ a targeted CRISPR/Cas9 screen in human microglia-neuron-astrocyte tri-cultures, identifying genes whose disruption enhances Aβ clearance. Promising candidates will be then validated in vivo using antisense oligonucleotides.The host laboratory has established the xenotransplantation model, the TurboID system, and the CRISPR platform, while I bring extensive expertise in human tri-cultures. I therefore believe that this makes an unprecedented opportunity to move beyond the state of the art and address a major gap in AD research.The project will generate the first in vivo map of the human microglial lysosomal proteome under Aβ pathology, uncovering candidate therapeutic targets to restore clearance. In doing so, it will open new avenues to modify AD and other neurodegenerative disorders where protein accumulation and microglia dysfunction are key drivers.