RESUMO
Objective:To evaluate the relationship between Karyopherin β2 (Kapβ2)-mediated nuclear translocation of nuclear inhomogeneous ribonucleoprotein A2/B1 (hnRNPA2/B1) and sevoflurane-induced brain neurotoxicity in a cellular experiment.Methods:The mouse hippocampal neuronal cell line HT22 cells were inoculated in confocal culture dishes and 6-well culture plates at a density of 2×10 5 cells/well and 1×10 6 cells/well and divided into 4 groups( n=12 each) by a random number table method: control group (GFP-C group) carrying green fluorescent protein (GFP) with empty adenovirus transfection, sevoflurane group (GFP-Sev group) carrying GFP with empty adenovirus transfection, control group (GFP-Sev group) transfected with Kapβ2 gene-overexpressing adenovirus, and sevoflurane group (Kapβ2-Sev group) transfected with Kapβ2 gene-overexpressing adenovirus. After 48 h of conventional incubation, empty adenovirus-carrying GFP (GFP-C and GFP-Sev groups) and Kapβ2 gene-overexpressing adenovirus (Kapβ2-C and Kapβ2-Sev groups) were transfected. After 48 h of transfection, the cells were conventionally incubated continuously in GFP-C and Kapβ2-C groups, and the cells were incubated for 3 h with 3% sevoflurane and then were conventionally incubated for 48 h in GFP-Sev and Kapβ2-Sev groups. The expression of Kapβ2, synaptophysin (SYP), postsynaptic density protein 95 (PSD95) and hnRNPA2/B1 nucleoplasmic ratio were measured in cells by Western blot. Immunofluorescence assay was used for hnRNPA2/B1 subcellular localization. Results:Compared with GFP-C group, the expression of SYP and PSD95 was significantly down-regulated, hnRNPA2/B1 nucleoplasmic ratio was decreased, and cytoplasmic hnRNPA2/B1 expression was up-regulated in GFP-Sev group, and Kapβ2 expression was significantly up-regulated in Kapβ2-C group ( P<0.05). Compared with Kapβ2-C group, the expression of SYP and PSD95 was significantly down-regulated, hnRNPA2/B1 nucleoplasmic ratio was decreased, and cytoplasmic hnRNPA2/B1 expression was up-regulated in Kapβ2-Sev group ( P<0.05). Compared with GFP-Sev group, the expression of Kapβ2, SYP and PSD95 was significantly up-regulated, hnRNPA2/B1 nucleoplasmic ratio was increased, and cytoplasmic hnRNPA2/B1 expression was down-regulated in Kapβ2-Sev group ( P<0.05). Conclusions:Kapβ2-mediated hnRNPA2/B1 nuclear translocation may be the endogenous protective mechanism against sevoflurane-induced brain neurotoxicity.