Roles of transient receptor potential melastatin 7 in hippocampal neuron injury / 临床麻醉学杂志

ABSTRACT

Objective To investigate the role of transient receptor potential melastatin 7 (TR PM7) in the protective role of sevoflurane preconditioning against hippocampal neuron injury caused by oxygen glucose deprivation (OGD).Methods Hippocampal neurons were harvested from postnatal day 1 SD rats,and randomly divided into 5 groupscontrol group (group C),sevoflurane group (group Sev),oxygen-glucose deprivation group (group OGD),sevoflurane+ OGD group (group SD) and sevoflurane+OGD+bradykinin group (group B).To build up the model of OGD,the neurons were cultured in a deoxygenated glucose-free medium and exposed to 95％ N2 and 5％％ CO2 in an anaerobic chamber equilibrated at 37℃ for 1.5 h,followed by replacement with glucose containing medium and return to a standard incubator for additional 24 h.The neurons in group C received no treatment.Group OGD was preconditioned with 2 ％ sevoflurane for 1 h.The neurons in group OGD were subjected to OGD.Group SD was preconditioned with 2％ sevoflurane for 1 h,followed by OGD at 24 h after the sevoflurane exposure.The neurons in group B was incubated in a medium supplemented with 200 μmol/L bradykinin (the selective agonist of TRPM7),followed sequen tially by the preconditioning of 2％ sevoflurane for 1 h and then OGD challenge.Twenty-four hours after re-oxygenation,The relative neuronal cell viability was determined by MTT assay,the neuronal apoptotic rate was analyzed by TUNEL assay,the protein expression of TRPM7 was detected by Western blot,the mRNA level of TRPM7 was estimated by real-time PCR,the neuronal release of IL-1β and TNF-α in the serum was measured by ELISA.Results Compared with group C,the mR NA and protein levels of TRPM7,the neuronal apoptotic rate,the mRNA and supernatant protein levels of IL-1β and TNFα were significantly up-regulated in group OGD (P＜0.05),whereas the cell viability was decreased (P＜0.05).Compared with group OGD,the mRNA and protein levels of TRPM7,the neuronal apoptotic rate,the mRNA and supernatant protein levels of IL1β and TNF-α were significantly down-regulated in group SD (P＜0.05),whereas the cell viability was increased (P＜0.05).Compared with group SD,the mRNA and protein levels of TRPM7,the neuronal apoptotic rate,the mRNA and supernatant protein levels of IL-1β and TNF-α were significantly up-regula ted in group B (P＜0.05),whereas the cell viability was decreased (P＜0.05).Conclusion Sevoflurane attenuates apoptosis and inflammatory responses induced by OGD via reduction of the overex pression of TRPM7 in the hippocampal neurons.