吡格列酮对谷氨酸诱导皮质神经元损伤保护作用及其抑制JNK信号的机制

目的观察吡格列酮对谷氨酸所致培养皮质神经元损伤的保护作用及作用机制。方法大鼠乳鼠大脑皮质神经元,培养7d后用于实验。实验分为对照组、谷氨酸组、谷氨酸+吡格列酮组、谷氨酸+SP600125组、SP600125组。用MTT法测定细胞活力;Hoechst33258核染色观察细胞凋亡的形态学改变;免疫荧光染色法检测磷酸化活化转录因子2(phospho-ATF2)的表达;Western blot检测磷酸化JNK1和JNK1总量的蛋白表达水平。结果谷氨酸(100μmol.L-1)作用24h可使体外培养的皮质神经元细胞活力明显下降,细胞凋亡百分比明显增加,磷酸化JNK1蛋白水平(谷氨酸作用2h后检测)和磷酸化ATF2表达明显增加。吡格列酮明显对抗谷氨酸引起的皮质神经元损伤,同时明显抑制谷氨酸引起的磷酸化JNK1及磷酸化ATF2表达增多。JNK抑制剂SP600125明显对抗谷氨酸引起的神经元损伤及phos-pho-ATF2表达增多。结论吡格列酮对谷氨酸引起的培养皮质神经元损伤具有明显的保护作用,吡格列酮的保护作用与抑制JNK信号转导通路有关。

Pioglitazone protects cortical neurons from glutamate induced neurotoxicity via inhibiting the JNK pathway

Aim To investigate whether pioglitazone has protective effect against glutamate induced neurotoxicity in cultured cortical neurons and its possible molecular mechanisms underlying pioglitazone's neuroprotective effects.Methods The cortical neurons were taken from newborn rats and used for experiments 7 days after culture.The neurons were randomly divided into control group;glutamate group; glutamate+piogli-tazone group;glutamate+SP600125 group;SP600125 group.Cell viability was determined by MTT.The morphology change of neurons was observed under a fluorescence microscope with fluorescence dye Hoechst 33258.Immunostaining was used to investigate the expression of phospho-ATF2 in neuronal cells.Western blot was performed to investigate the protein level of phospho-JNK1 and total JNK1.Results Pioglitazone markedly reduced the damage of cortical neurons caused by glutamate.Pioglitazone also significantly inhibited glutamate induced up-regulation of phospho-JNK1 protein level and phospho-ATF2 expression.SP600125, an inhibitor of JNK, antagonized the toxicity induced by glutamate.Conclusions Pioglitazone can protect cultured cortical neurons from glutamate induced damage.The protective effect of pioglitazone appears to be associated with inhibiting the c-Jun N-terminal protein kinase signaling pathway.