Fig. 2

Fer-1 inhibited ferroptosis and neuroinflammation caused by intranasal N-GQDs exposure in the hippocampus. a Schematic workflow of the N-GQDs and Fer-1 treatments in mice; b, c representative fluorescence images presented dead cells showing green marked by TUNEL dye in hippocampus. The nucleus showed blue using DAPI. Arrows indicated TUNEL-positive cells. And the quantitative results of TUNEL positive cells; d representative fluorescence images presented ferrous iron level showing orange marked by FerroOrange dye in hippocampus. The nucleus showed blue using DAPI. Arrows indicated the ferrous iron accumulation; e representative immunohistochemical images presented 4-HNE in hippocampus. The arrows indicate increased expression of 4-HNE that displayed tan color; f, g representative immunofluorescence images presented microglia in hippocampus. The Iba1 showed red using primary antibodies with cy3-linked secondary antibodies, and the nucleus showed blue using DAPI. And the quantitative results of Iba1 positive cells; h representative histological images presented the hippocampus stained with H&E. The arrows indicated infiltrated inflammatory cells; i, j the levels of IL-1ß and TNF-α in hippocampus. For merely N-GQDs exposure groups, each mouse was intranasally instilled with saline, 0.1 and 1 mg/kg BW N-GQDs every other day for 28 days. For Fer-1 pre-treatment groups, each mouse was intraperitoneally injected with 5 mg/kg BW Fer-1 every fourth day and intranasally instilled with 1 mg/kg BW N-GQDs every other day for 28 days (mouse n = 6). Data are showed as mean ± SD of three independent experiments. The one-way ANOVA followed by the Dunnett’s t test were used to determine statistical significance (*P < 0.05, **P < 0.01, ***P < 0.001 vs. the control or 1 mg/kg BW N-GQDs)