CRISPRa Lipid Nanocomplex‐Mediated Mt3 Targeting Enhances Astrocytic Endocytosis of Amyloid‐β in an Alzheimer's Disease Mouse Model

Abstract Metallothionein 3 (Mt3) is crucial for cellular homeostasis and neuroprotection, with accumulating evidence linking it to amyloid‐beta (Aβ) clearance by astrocytes. This study developed a CRISPR activator (CRISPRa) system using lipid nanoparticles to selectively upregulate Mt3 in astrocytes, aiming to enhance Aβ endocytosis in an Alzheimer's disease (AD) mouse model. To directly assess the therapeutic potential of Mt3 activation in a specific brain region, stereotaxic injection is utilized to deliver the CRISPRa lipid nanocomplexes. This approach enabled precise in vivo brain delivery and Mt3 activation. The findings reveal that CRISPRa lipid nanocomplex‐mediated Mt3 upregulation significantly boosts Aβ uptake by astrocytes, leading to a marked reduction in Aβ plaque accumulation in AD mouse brains. These results highlight CRISPRa lipid nanocomplex‐mediated Mt3 targeting as a promising strategy to enhance endogenous Aβ clearance, presenting a novel therapeutic avenue for AD.