2021年第48卷第7期目录
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封面故事:动物的氧化应激(oxidative stress,OS) 是指由于动物体内氧化与抗氧化作用之间失
衡,体内氧自由基(oxygen free radical,OFR) 产生过多,无法及时清除,产生大量氧化中间产
物,进而导致动物机体的的损伤. 研究证明,氧化应激中产生的ROS能诱导自噬(autophagy) 的发
生,自噬能清除氧化应激损伤的线粒体、内质网、过氧化物酶体及蛋白质,减缓细胞死亡. 而当自
噬过程被阻断时,将造成毒性蛋白质聚集和线粒体功能损伤,从而进一步加剧氧化应激. 杨阳等的
研究发现,JNK是GALR2调控海马神经元氧化应激的下游靶酶. 被抑制的JNK阻碍了氧化应激神经
元中上调的GALR2对自噬信号通路的激活,证实氧化应激激活的GALR2可通过调节JNK信号通路
上调氧化应激海马神经元中的自噬活性,从而保护神经元免遭氧化应激损伤.
(杨阳,张晨,冯露秋,谢清,杨成迎,甘玲. 甘丙肽2 型受体对氧化应激海马神经元自噬的调控作
用及机制研究,本期第817~826 页)
Cover Story:The aim of this study is to elucidate the molecular mechanism of Galanin receptors type 2(GALR2)
which involved in regulation of oxidative stress in the hippocampus. We used real-time PCR technique to
investigate the change of GALR2 expression in hippocampus of piglets and hippocampal neurons of rats, based
on the successfully constructed oxidative stress model. Real-time PCR, Western blotting and transmission electron
microscopy were used to further explore the relationship between the signal pathway mediated by GALR2 and
autophagy. The results showed that the transcription levels of GALR2 were up-regulated in the hippocampus of
oxidative stressed piglets and rat hippocampal neurons compared with the control group (P<0.01; P<0.05). At the
same time, the transcription levels of LC3, ATG5 and Beclin-1 in oxidative stressed neurons were up-regulated (P
<0.05; P<0.05; P<0.01). Correlation analysis showed that GALR2 was positively correlated with LC3, ATG5 and
Beclin-1 (P<0.05; P<0.05; P<0.01). The treatment with M871, a specific inhibitor of GALR2, decreased the
activity of hippocampal neurons under oxidative stress (P<0.01) , increased the number of autophagosomes (P<
0.01) and transcription levels of LC3, Beclin-1 and ATG5(P<0.01) , and increased the ratio of LC3- Ⅱ/actin and
P62 protein level (P<0.05) , showing that the autophagy of hippocampal neurons, which was up-regulated by
oxidative stress, was inhibited with the inhibition of GALR2 expression, thus weakening the resistance to
oxidative damage and decreasing the viability of neurons. Simultaneously, M871 treatment also decreased the upregulated
protein level (P<0.01) and the phosphorylation level of JNK (P<0.05) in oxidative stressed neurons,
indicating that JNK is the downstream target enzyme of GALR2 in hippocampal neurons under oxidative stress.
However, treatment with JNK specific inhibitor SP600125 lowered the ratio of LC3-II/actin, which was upregulated
by oxidative stress (P<0.01), showing the inhibition of JNK blocks the activation of the autophagic
pathway by an up-regulated GALR2 in neurons. To sum up: under oxidative stress, the up-regulated GALR2 in
hippocampal neurons can activate the autophagy pathway by up-regulating JNK signal pathway, thus attenuate
oxidative stress injury and protect neurons.
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综述与专论
研究报告
技术与方法
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