Objective To investigate the protective effect of miR-214 on propofol induced neuronal injury and its biological mechanism.
Methods Seven day old SD male rats were randomly divided into four groups (15 rats in each group): normal saline group (NS), propofol anesthesia exploratory group (model), miR-NC group and miR-214 group. Except NS group, the other groups established propofol anesthesia open exploratory model. The miR-NC group and the miR-214 group injected miR-NC agomir or miR-214 agomir into the hippocampus before anesthesia respectively. Immunofluorescence method was used to detect the expression of mTORC1 in hippocampus, TUNEL staining was used to detect apoptosis in hippocampus, and RT qPCR was used to analyze the expression of miR-214 in hippocampus. The miR-214 inhibitor and mTORC1 inhibitor were transfected into HT22 hippocampal neurons respectively, and then exposed to propofol. The cell survival was analyzed by flow cytometry and the expression of TEFB and C-caspase3 protein was analyzed by Western blot.
Results Compared with NS group, miR-214 in hippocampus of model group was significantly decreased (P<0.05), and apoptosis of hippocampal neurons was significantly increased (P<0.05). Compared with the model group, the apoptosis of hippocampal neurons in miR-214 group decreased (P<0.05). Bioinformatics prediction showed that there was a specific binding site between mTORC1 and miR-214. The immunofluorescence test showed that compared with NS group, the model group induced an increase in the expression of mTORC1 in hippocampal nerve tissue (P<0.05), and miR 214 treatment significantly reduced the expression of mTORC1 (P<0.05). In addition, compared with NC control group, si-mTORC1 transfection significantly reduced the apoptosis rate of HT22 hippocampal neurons exposed to propofol, significantly increased TFEB expression (P<0.01), and decreased C-caspase3 (P<0.05). However, miR-214 inhibitor transfection significantly reversed the protective effect of si-mTORC1 and the induced changes of TFEB and C-caspase3 protein expression (P<0.05).
Conclusion miR-214 may reduce the neurotoxicity of propofol through mTORC1-TFEB pathway and improve the survival rate of neurons.