Role of ERK1/2/CREB/BDNF signaling pathway in dexmedetomidine-induced inhibition of propofol-caused apoptosis in isolated hippocampal neurons of fetal rats / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the role of extracellular signal-regulated kinase 1/2 (ERK1/2)/cyclic adenosine monophosphate response element-binding protein (CREB)/brain-derived neurotrophic factor (BDNF) signaling pathway in dexmedetomidine-induced inhibition of propofol-caused apoptosis in isolated hippocampal neurons of fetal rats.Methods:Pregnant Sprague-Dawley rats at 16 days of gestation were sacrificed, and the fetal rats were taken out, and hippocampal neurons of fetal rats were obtained and primarily cultured in vitro for 7 days.The neurons were divided into 9 groups ( n=12 each) using a random number table method: control group (group C), fat emulsion group (group I), dimethyl sulfoxide (DMSO) group, dexmedetomidine group (group D), propofol group (group P), propofol plus dexmedetomidine group (group PD), PD98059 plus propofol plus dexmedetomidine group (group PDP), MH89 plus propofol plus dexmedetomidine group (group HDP), and KG501 plus propofol plus dexmedetomidine group (group KDP). Group C received no treatment.In group I, 20% fat emulsion was added, and the neurons were incubated for 30 min, and 0.25% DMSO was added in group DMSO, and the neurons were incubated for 30 min.Dexmedetomidine at a final concentration of 10 μmol/L was added, and the neurons were incubated for 30 min in group D. Propofol at a final concentration of 100 μmol/L was added, and the neurons were incubated for 3 h in group P. In group PD, dexmedetomidine at a final concentration of 10 μmol/L was added, the neurons were incubated for 30 min, propofol at a final concentration of 100 μmol/L was added, and the neurons were incubated for 3 h. In PDP, HDP and KDP groups, 25 μmol PD98059 (p-ERK1/2 inhibitor), 10 μmol H89 (p-CREB inhibitor) and 25 μmol KG501 (CREB inhibitor) were added, respectively, the neurons were incubated for 30 min, dexmedetomidine at a final concentration of 10 μmol/L was added, the neurons were incubated for 30 min, and propofol at a final concentration of 100 μmol/L was added, and the neurons were incubated for 3 h. The cell ultrastructure was observed with the transmission electron microscope, the apoptosis in neurons was detected by flow cytometry, the expression of ERK1/2, CREB and BDNF mRNA was detected by quantitative real-time polymerase chain reaction, and the expression of p-ERK1/2, CREB, p-CREB, BDNF and cleaved caspase-3 was detected by Western blot. Results:Compared with group C, the apoptosis rate was significantly increased, the expression of p-ERK1/2 and p-CREB was down-regulated, and the expression of cleaved caspase-3 was up-regulated in P, PD, PDP, HDP and KDP groups, and the expression of BDNF was significantly down-regulated in P, PDP, HDP and KDP groups ( P<0.05). Compared with group P, the apoptosis rate was significantly decreased, the expression of p-ERK1/2, p-CREB and BDNF was up-regulated, and the expression of cleaved caspase-3 was down-regulated in group PD ( P<0.05). Compared with group PD, the apoptosis rate was significantly increased, the expression of p-ERK1/2, p-CREB and BDNF was down-regulated, and the expression of cleaved caspase-3 was up-regulated in PDP, HDP and KDP groups ( P<0.05). Conclusion:The ERK1/2/CREB/BDNF signaling pathway is involved in dexmedetomidine-induced inhibition of propofol-caused apoptosis in isolated hippocampal neurons of fetal rats.