丙泊酚通过上调纤维细胞生长因子的表达激活磷酸肌醇3激酶-蛋白激酶B和磷酸化细胞外信号调节激酶1／2信号通路抑制体外培养神经元缺血／再灌注损伤

Propofol activate phosphotylinosital 3 kinase-protein kinase B and phosphorylated extracellular signal-regulated kinase 112 signal pathway via upregulating the expression of basic fibroblast growth factor to inhibit the injury of the cerebral ischemia/reperfusion injury

目的探讨丙泊酚在脑缺血，再灌注损伤（ischemia／reperfusioninjury，I／RI）中发挥的作用及其具体机制。方法采用氧糖剥夺再灌注（oxygen-glucose deprivation／reperfusion，OGD／RP）法体外构建缺血／再灌注细胞模型，将细胞分为对照组、OGD／RP组、丙泊酚＋OGD／RP组。采用甲基噻唑基四唑（methylthiazolyl tetrazolium，MTF）法检测皮质神经细胞存活率，AnnexinV-PI检测细胞凋亡情况，即时聚合酶链式反应（real-time polymerase chain reaction，RT-PCR）方法检测碱性成纤维细胞生长因子（basic fibroblast growth factor，bFGF）的mRNA表达情况，免疫印迹法（Westernblot）检测丙泊酚对皮质神经细胞内bFGF，磷酸化蛋白激酶B（phosphorylated proteinkinaseB，pAkt）以及磷酸化细胞外信号调节激酶1／2（phosphorylated extracellular signal-regulatedkinase1／2，pERKl／2）蛋白表达的影响；采用小干扰RNA构建bFGF沉默的细胞。结果OGD／RP处理组神经细胞凋亡率为43．2％，经10mg／L的丙泊酚预处理后，细胞的凋亡率降为19．5％。与对照组比较，OGD处理后，细胞中bFGF的含量显著下调（P〈0．05），丙泊酚处理的皮质神经元中bFGF含量显著高于OGD处理组（P〈0．05）。丙泊酚能够上调pAKT以及pERKI／2的表达，激活这两条信号通路。沉默bFGF或者施加磷酸肌醇3激酶．蛋白激酶B（phosphotylinosital3kinase-proteinkinaseB，P13K-Akt）以及pERK1／2信号通路抑制剂都会导致细胞存活率显著下降（P〈0．05），抑制P13K-Akt以及pERKl／2的激活。结论丙泊酚可以通过上调bFGF的表达，激活P13K-Akt和ERK1／2信号通路，增加皮质神经元的存活。

Objective To study the effect of propofol on cerebral ischemia/reperfusion injury （I/RI） and the relative mechanism. Methods The cerebral ischemia/reperfusion model was produced by oxygen glucose deprivation and reperfusion in vitro, methyl thiazoly] tetrazolium （MTF） assay was used to detect the proliferative effect of propofol. Apoptotic cells were detected with Annexin V staining. The expression level of basic fibroblast growth factor （bFGF） mRNA was measured by RT-PCR. The expression levels of bFGF, phosphorylated protein kinase B （pAkt） and phosphoiylated extracellular signal-regulated kinase 1/2 （pERK1/2） protein expression were detected by Western blot. Silence of bFGF in cortical neurons by small interfering RNA. Results The apoptosis rate of neurons in oxygen-glucose deprivation/reperfusion （OGD/RP） group was 43.2%. After treated with 10 mg/L propofol, the apoptosis rate of neurons was reduced to 19.5%. The expression levels of bFGF protein in OGD treated group was significantly lower than the control group（P〈0.05）, and the bFGF level was markedly upregulated in propofol treated group（P〈0.05）. Propofol could upregulate the expression of pAkt and pERK1/2, and activate the two signaling pathways. Silence the expression of bFGF or treatment with the inhibitor of phosphotylinosital 3 kinase-protein kinase B （PI3K-Akt） and ERKI/2 signal pathway both resulted in the decrease of neurons viability （P〈O.05）, and the inhibition of PI3K-Akt and ERKI/2 activation. Conclusions Propofol could activate PI3K-Akt and ERK1/2 signal pathway via upregulating the expression of bFGF, and promote the survival of cortical neurons.