Nanogold induces anti-inflammation against oxidative stress induced in human neural stem cells exposed to amyloid-beta peptide

Alzheimer's disease (AD) is a neurodegenerative disorder with progressive memory loss resulting in dementia. Amyloid-beta (AB) peptides play a critical role in the pathogenesis of the disease by promoting inflammation and oxidative stress, leading to neurodegeneration in the brains of AD patients. Numerous in vitro 3D cell culture models are useful mimics for understanding cellular changes that occur during AD under in vivo conditions. The 3D Bioprinter developed at the CELLINK INKREDIBLE was used in this study to directly investigate the influence of 3D conditions on human neural stem cells (hNSCs) exposed to AB. The development of anti-AD drugs is usually difficult, mainly due to a lack of therapeutic efficacy and enhanced serious side effects. Gold nanoparticles (AuNPs) demonstrate benefits in the treatment of several diseases, including AD, and may provide a novel therapeutic approach for AD patients. However, the neuroprotective mechanisms by which AuNPs exert these beneficial effects in hNSCs treated with AB are still not well understood. Therefore, we tested the hypothesis that AuNPs protect against AB-induced inflammation and oxidative stress in hNSCs under 3D conditions. Here, we showed that AuNPs improved the viability of hNSCs exposed to AB, which was correlated with the reduction in the expression of inflammatory cytokines, such as TNF-a and IL-1B. In addition, AuNPs rescued the levels of the transcripts of inhibitory kappa B kinase (IKK) in AB-treated hNSCs. The AB-mediated increases in mRNA, protein, and nuclear translocation levels of NF-?B (p65), a key transcription factor involved in inflammatory responses, were all significantly abrogated following co-treatment of hNSCs with AuNPs. In addition, treatment with AuNPs significantly restored iNOS and COX-2 levels in AB-treated hNSCs. Importantly, hNSCs co-treated with AuNPs were significantly protected from AB-induced oxidative stress, as detected using the DCFH-DA and DHE staining assays. Furthermore, hNSCs co-treated with AuNPs were significantly protected from the AB-induced reduction in the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and Nrf2 downstream antioxidant target genes (SOD-1, SOD-2, Gpx1, GSH, Catalase, and HO-1). Moreover, AuNPs reduced the aggregates and increased the proteasome activity and the expression of HSP27 and HSP70 genes in AB-treated hNSCs. Taken together, these findings provide the first evidence extending our understanding of the molecular mechanisms under 3D scaffold conditions by which AuNPs reverse the inflammation and oxidative stress-induced in hNSCs exposed to AB. These findings may facilitate the development of novel treatments for AD.

Automated summary

Alzheimer's disease is a neurodegenerative disorder characterized by memory loss, with amyloid-beta peptides playing a key role in its pathogenesis. Gold nanoparticles show potential benefits in treating AD, potentially offering a new therapeutic approach for patients.