Necrostatin-1 inhibits the degeneration of neural cells induced by aluminum exposure

Abstract

There are many in vivo and in vitro studies suggested the involvement of apoptosis in neurodegenerative processes. There is considerable evidence that various complex events may contribute to neural cell death. The present study focuses on the underlined neurodegenerative mechanism and the preventive effect of necrostatin-1 (Nec-1) on neural cell death induced by aluminum (Al). Al-exposed primary cultures of newborn mice cortical cells were separately treated with 3-methylamphetamine (3-MA), benzyloxycarbonylvalyl-alanyl-aspartic acid (O-methyl)-fluoro-methylketone (zVAD-fmk), and Nec-1, the cell viability analysis was used to evaluate cell damage from apoptosis, necroptosis and autophagy. Morphology of neural cells treated with 2 mM Al, and 2 mM Al plus 60 μM Nec-1 were examined by fluorescent microscope, and the cell death rates were quantified by cytometry. For the in vivo experiments, male ICR mice were microinjected with normal saline, 2 mM Al, and 2 mM Al plus Nec-1 at the concentrations of 2 mM, 4 mM and 8 mM into the lateral cerebral ventricles. The Morris water maze task was performed in 20 days after intracerebroventricular injection, Nissl staining was used to demonstrate the loss of Nissl substance and the number of neural cells, and western blot was used to analyze the expressing of cell death and Alzheimer's disease related proteins. The cell viabilities inhibited by Al could be enhanced by 3-MA, zVAD-fmk and Nec-1, of which Nec-1 improved the cell viability most significantly. Furthermore, the cell viability of neural cells treated with Nec-1 increased concentration-dependently, and the expressions of cell death-related proteins were decreased also in a concentration-dependent manner. The in vivo experiments indicated that administration of Nec-1 on Al-treated mice significantly improved learning and memory retention in the Morris water maze task, decreased the neural cells death and inhibited the expression of Alzheimer's disease related proteins in the mice brain. The present study provides the first direct evidence of a connection between necroptosis and neurodegeneration, which indicates that necroptosis is involved in neurodegenerative cell death. Furthermore, Nec-1 may be useful for the prevention and treatment of neurodegenerative disorders.