Roles of receptor-interacting protein kinase 1 in SH-SY5Y cells with beta amyloid-induced neurotoxicity.

Alzheimer's disease (AD), the major cause of dementia, affects the elderly population worldwide. Previous studies have shown that depletion of receptor-interacting protein kinase 1 (RIPK1) expression reverted the AD phenotype in murine AD models. Necroptosis, executed by mixed lineage kinase domain-like (MLKL) protein and activated by RIPK1 and RIPK3, has been shown to be involved in AD. However, the role of RIPK1 in beta-amyloid (Aβ)-induced necroptosis is not yet fully understood. In this study, we explored the role of RIPK1 in the SH-SY5Y human neuroblastoma cells treated with Aβ 1-40 or Aβ 1-42. We showed that Aβ-induced neuronal cell death was independent of apoptosis and autophagy pathways. Further analyses depicted that activation of RIPK1/MLKL-dependant necroptosis pathway was observed in vitro. We demonstrated that inhibition of RIPK1 expression rescued the cells from Aβ-induced neuronal cell death and ectopic expression of RIPK1 was found to enhance the stability of the endogenous APP. In summary, our findings demonstrated that Aβ can potentially drive necroptosis in an RIPK1-MLKL-dependent manner, proposing that RIPK1 plays an important role in the pathogenesis of AD.