Effects of silica nanoparticles exposure on cortical stress and neuroinflammation in neonatal mice

FU Jingjing; XIAO Rui; GAO Junwei; MA Yuanyuan; FAN Xiaotang; ZHU Jingci

doi:10.13431/j.cnki.immunol.j.20180007

Abstract：The study aimed to investigate the effects of silica nanoparticles (SiO2-NPs) on cortical stress and neuroinflammation in neonatal mice,and explore the possible mechanisms of SiO2-NPs neurotoxicity.Neonatal mice were randomly divided into three groups:low dose (10 mg/3 ml),high dose SiO2-NP-treatment group (50 mg/3 ml) and control group.From postnatal day 1 (P1) to P7,mice were treated with SiO2-NP suspension 10 mg/3 ml,50 mg/3 ml or 3 ml normal saline by aerosol inhalation respectively,30 min per day.Immunohistochemistry techniques were used to detect the expression of glucocorticoid receptor (GR),ionized calcium binding adapter molecule 1 (Iba1) and glial fibrillary acidic protein (GFAP) in the cerebral cotex of mice on P8;ELISA was used to measure the concentration of IL-6,TNF-α,and IL-1β in cortex.Data showed that the expression of GR in cortex of high dose SiO2-NP-treatment group was significantly increased,as compared to control group (P＜0.05).Compared to the control group,microglia in cortex of low dose and high dose SiO2-NP-treatment group were both significantly increased (P＜0.05,P＜0.01).And the number of cortical GFAP-labeled astrocytes of high dose SiO2-NP-treatment group was significantly higher than that of control group and low dose SiO2-NP-treatment group (P＜0.01,P＜0.05).Furthermore,the expression of inflammatory cytokines TNF-α,IL-6,IL-1β were all up-regulated with the increased dose of SiO2-NP exposure,as compared to control group.In conclusion,SiO2-NP exposure in neonatal mice results in cortical stress and neuroinflammatory response,and neurotoxicity of high dose SiO2-NP exposure is more obvious in cortex of neonatal mice.