Abstract:

Activated nucleotide binding to the oligonucleotide receptor protein 3 (NLRP3) inflammasome is possibly involved in the pathogenesis of Alzheimer’s disease through oxidative stress and neurogenic inflammation. Low expression of the signal transducer and activator of transcription 3 (STAT3) gene may promote the occurrence of neurodegenerative diseases to some extent. To clarify the roles of the NLRP3 inflammasome and STAT3 expression in oxidative stress, (1) SHSY5Y cells were incubated with 1 mM H₂O₂ to induce oxidative stress injury, and the expression of human-cell-specific signal transduction, STAT3-shRNA silencing signal transduction and STAT3 were detected. Cells were pretreated with Ca²⁺ chelator BAPATA-AM (0.1 mM) for 30 minutes as a control. (2) Western blot assay was used to analyze the expression of caspase-1, NLRP3, signal transduction and STAT3. Enzyme-linked immunosorbent assay was used to analyze interleukin-1β levels. Flow cytometry was carried out to calculate the number of apoptotic cells. We found that H₂O₂ treatment activated NLRP3 inflammasomes and decreased phosphorylation of signal transduction and STAT3 serine 727. BAPTA-AM pretreatment abolished the H₂O₂-induced activation of NLRP3 inflammasomes, caspase-1 expression, interleukin-1β expression and apoptosis in SHSY5Y cells, and had no effect in cells with downregulated STAT3 expression by RNAi. The findings suggest that downregulation of signal transduction and STAT3 expression may enhance the oxidative stress mediated by NLRP3, which may not depend on the Ca²⁺ signaling pathway.

Key words: nerve regeneration, signal transducer and activator of transcription 3, calcium, caspase-1, nucleotide binding to the oligonucleotide receptor protein 3, inflammasome, hydrogen peroxide, Alzheimer’s disease, shRNA, SHSY5Y cells, neural regeneration