Silica nanoparticles induced intrinsic apoptosis in neuroblastoma SH-SY5Y cells via CytC/Apaf-1 pathway.

The present study was to investigate effects of Silica nanoparticles (SiNPs) on nervous system and explore potential mechanisms in human neuroblastoma cells (SH-SY5Y). Cytotoxicity was detected by cell viability and Lactate dehydrogenase (LDH) release. Flow cytometry analysis was applied to assess mitochondrial membrane potential (MMP) loss, intracellular Ca2+ and apoptosis. To clarify the mechanism of SiNPs-induced apoptosis, intrinsic apoptosis-related proteins were detected. Our results showed that SiNPs caused cytotoxicity, cell membrane damage and Ca2+ increase in a dose-dependent manner in SH-SY5Y cells. Both the mitochondrial membrane potential (MMP) loss and potential mitochondria damage resulted in Cyt C release to the cytoplasm. The elevated Cyt C and Apaf1 further triggered intrinsic apoptosis via executive molecular caspase-9 and caspase-3. The present study confirmed that SiNPs induced intrinsic apoptosis in neuroblastoma SH-SY5Y cells via CytC/Apaf-1 pathway and provided a better understanding of the potential toxicity induced by SiNPs on human neurocyte.