Mechanism of neuronal damage induced by sevoflurane: the relationship between phosphorylation of Tau protein and apolipoprotein E containing 18 kDa fragments / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the relationship between phosphorylation of Tau protein and apolipoprotein E (ApoE) containing 18 kDa fragments and investigate the mechanism of neuronal damage induced by sevoflurane.Methods:Primary neurons (ApoE3 and ApoE2 genotypes, 24 dishes for each genotype) of fetal mice cultured until the 5th day were divided into 4 groups ( n=12 each) using a random number table method: ApoE3 control group (A3C group), ApoE3 sevoflurane group (A3S group), ApoE2 control group (A2C group) and ApoE2 sevoflurane group (A2S group). Neurons were treated with 21% oxygen + 5% carbon dioxide + 4.1% sevoflurane for 4 h in A3S and A2S groups, while the neurons were only treated with 21% oxygen + 5% carbon dioxide in A3C and A2C groups.The cell proteins were then extracted to detect the expression of full-length ApoE and ApoE, AT8 and PHF1 containing 18 kDa fragments (by Western blot), expression of ApoE mRNA (by real-time polymerase chain reaction), and concentrations of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in the supernatant (by enzyme-linked immunosorbent assay). Results:Compared with A2C group, the expression of ApoE mRNA and full-length ApoE in neurons was up-regulated ( P<0.05), and no significant change was found in the expression of AT8 and PHF1 and concentrations of TNF-α and IL-6 in the supernatant in A2S group ( P>0.05). Compared with A3C group, the expression of ApoE mRNA, full-length ApoE, and ApoE, AT8 and PHF1 containing 18 kDa fragments was up-regulated, and the concentrations of TNF-α and IL-6 in the supernatant were increased in A3S group ( P<0.05). Conclusion:Sevoflurane may promote phosphorylation of Tau proteins and increase inflammatory responses through up-regulating the expression of ApoE containing 18 kDa fragments, thus leading to neuronal damage.