p75 neurotrophin receptor and its novel interaction partner, NIX, are involved in neuronal apoptosis after intracerebral hemorrhage
p75 neurotrophin receptor and its novel interaction partner, NIX, are involved in neuronal apoptosis after intracerebral hemorrhage
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p75 神经营养素受体及其新型相互作用伙伴 NIX 参与脑出血后神经元凋亡
DOI：
10.1007/s00441-016-2510-y
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发表时间：
2017-04-01
影响因子：
3.6
通讯作者：
Ke, Kaifu
中科院分区：
文献类型：
--
作者：
Shen, Jiabing;Chen, Xiaomei;Ke, Kaifu
本实验室通过筛选人胎脑双杂交文库，发现NIX是一种新的p75神经营养因子受体（p75 NTR）结合蛋白，它是一种促凋亡蛋白。我们进一步研究了这两种蛋白的相互作用以及p75 NTR和NIX在脑出血（ICH）诱导的神经元死亡中的可能作用。利用分裂泛素酵母双杂交系统，我们发现p75 NTR中的“铜”结构域和NIX中的TM区域足以使这两种蛋白相互作用。免疫共沉淀和体外结合试验证明p75 NTR和NIX之间存在直接的相互作用。p75 NTR在翻译后水平稳定NIX蛋白。p75 NTR还能与NIX共同促进神经元PC 12细胞凋亡，并影响NIX诱导的JNK-p53-Bax通路。先前的工作已经表明，p75 NTR和NIX分别在人ICH和大鼠ICH模型中的神经元中被诱导。我们证实，这两个p75 NTR和NIX水平上调谷氨酸处理的原代皮层神经元（细胞在体外模型ICH）和大鼠ICH模型。谷氨酸暴露增加了p75 NTR和NIX之间的关联，并提高了JNK-p53-Bax通路的激活和神经元凋亡;所有这些观察结果在大鼠ICH模型中是相似的。重要的是，p75 NTR和NIX似乎参与皮质神经元凋亡，因为敲低p75 NTR或NIX不仅抑制JNK通路，而且损害神经元凋亡。因此，p75 NTR和NIX可能在ICH诱导的神经元凋亡中起关键作用。
Recently, NIX, a pro-apoptotic BH3-only protein, was found to be a novel p75 neurotrophin receptor (p75NTR) binding protein by screening a human fetal brain two-hybrid library in our laboratory. We further study the interaction of these two proteins and the possible roles of p75NTRand NIX in intracerebral hemorrhage (ICH)-induced neuronal death. Using the split-ubiquitin yeast two-hybrid system, we found that the “Copper” domain in p75NTRand the TM region in NIX were sufficient for the interaction of these two proteins. Co-immunoprecipitation and in vitro binding assays demonstrated the direct interaction between p75NTRand NIX. NIX protein was stabilized by p75NTRat post-translational levels. Moreover, p75NTRwas able to work together with NIX to promote apoptosis and affected the NIX-induced JNK-p53-Bax pathway in neuronal PC12 cells. Previous work has indicated that p75NTRand NIX are induced in neurons in human ICH and the rat ICH model, respectively. We confirm that both p75NTRand NIX levels were up-regulated in glutamate-treated primary cortical neurons (a cellular in vitro model for ICH) and in the rat ICH model. Glutamate exposure increased the association between p75NTRand NIX and elevated the activation of the JNK-p53-Bax pathway and neuronal apoptosis; all of these observations were similar in the rat ICH model. Importantly, p75NTRand NIX appeared to be involved in cortical neuronal apoptosis, because knockdown of p75NTRor NIX not only inhibited the JNK pathway but also impaired neuronal apoptosis. Thus, p75NTRand NIX may play critical roles in ICH-induced neuronal apoptosis in vitro and in vivo.