Protective effects of miR-34a on brain function of mice with sepsis by regulating Notch-1/NF-κB signaling pathway / 中华急诊医学杂志

ABSTRACT

Objective To observe the dynamic changes of TNF-α,IL-1β,IL-6,IL-10,and expressions of Notch-1,NF-κB mRNA and their protein levels in the brain tissue of septic mice and intervention effects of intrathecal injection of lentiviral vector of miR-34a gene for regulating Notch-1/NF-κB signaling pathway.Methods A total of 54 mice of clean grade were divided randomly (random number) into four groups,namely sham group (n =9),in which sham-operated laparotomy was performed;CLP group (n=15),in which the cecum ligation operation (CLP) was performed;NC group (n =15),in which intrathecal injection of lentivirus 5 μL (concentration 5 × 108 TU/mL),one time per day,for 3 days,then CLP was performed on the seventh day;intervention group (n =15),in wihch intrathecal injection of miR-34a lentivirus 5 μL (concentration 5 × 108 TU/mL),one time per day,for 3 days,then CLP was performed on the seventh day.The mice of four groups were sacrificed 24 h after modeling or operation.The changes of behavior of mice was observed and the neurological scores were assessed 24 h after CLP.The levels of TNF-α,IL-1β,IL-6 and IL-10 in the brain were measured by ELISA method.The mRNA expression and protein levels of Notch-1 and NF-κB in the brain tissue were measured by real-time PCR and Western blot method,respectively.Pathological changes of brain tissue were observed under light microscope.Results The neurological scores,the cerebral TNF-α,IL-6 levels,the mRNA expression and protein level of NF-κB (P＜0.01),and IL-1β levels (P ＜0.05) in CLP group 24 h after modeling were higher than those in sham group.The cerebral IL-10 level and the mRNA expression and protein level of Notch-1 (P ＜ 0.01) in CLP group 24 h after modeling were lower than those in sham group.The neurological scores,the cerebral TNF-α and IL-1β levels,and the protein level of NF-κB (P ＜0.01),and IL-6 (P ＜ 0.05) in NC group 24 h after modeling were higher than those in sham group.The cerebral IL-10 level,the mRNA expression and protein level of Notch1 in NC group 24 h after modeling were lower than those in sham group.There were no significant difference in neurological socres,IL-1β and IL-6 levels between intervention group and CLP group (P ＞ 0.05).The IL-10 level (P ＜ 0.05) and the mRNA expression (P ＜ 0.05) and protein level (P ＜ 0.01) of Notch-1 in intervention group 24 h after modeling were lower than those in CLP group.There were no significant difference in biomarkers between NC group and CLP group (P ＞ 0.05).The degree of cerebral damage found under light microscope was also ameliorated in intervention group compared with CLP group 24 h after modeling.Conclusions The effects of miR-34a via regulating Notch-1/NF-κB signaling pathway on brain function exerts cerebral protective effects in septic mice.