Glutathione-conjugated gold nanoparticles mitigate amyloid-beta-induced neuroinflammation and tauopathy through inhibition of NF-κB, the NLRP3 inflammasome axis in 3D human neural stem cell models.

Neuroinflammation and tauopathy are central pathological features of Alzheimer's disease (AD), often exacerbated by amyloid-β (Aβ) accumulation. This study evaluated the therapeutic potential of glutathione-conjugated gold nanoparticles (GSH-AuNPs) in mitigating Aβ-induced cytotoxicity and inflammation using a physiologically relevant 3D human neural stem cell (hNSCs) model cultured within a gelatin scaffold. This 3D system provided a tissue-like microenvironment to closely mimic in vivo conditions. GSH-AuNP treatment significantly rescued Aβ-induced loss of cell viability and suppressed tumor necrosis factor-α (TNF-α) secretion. At the molecular level, GSH-AuNPs downregulated the expression of key inflammatory mediators, including IKKα, IKKβ, and NF-κB (p65), and inhibited nuclear translocation of p65. Additionally, GSH-AuNPs attenuated the expression of proinflammatory enzymes iNOS and COX-2 and suppressed activation of the NLRP3 inflammasome, as evidenced by reduced levels of NLRP3, ASC, caspase-1, IL-1β, and IL-18. Proteostasis was improved by restoring chymotrypsin-like proteasome activity and reducing phosphorylated tau accumulation. Furthermore, GSH-AuNPs enhanced cellular resilience by upregulating heat shock factor 1 (HSF1) and normalizing the expression of key molecular chaperones HSP27, HSP70, and HSP90. Our findings highlight the multifaceted protective effects of GSH-AuNPs in counteracting Aβ-induced neuroinflammation and tauopathy. These results support the potential application of GSH-AuNPs as a nanomedicine-based therapeutic strategy for AD.