NR2B phosphorylation at tyrosine 1472 contributes to brain injury in a rodent model of neonatal hypoxia-ischemia.
NR2B phosphorylation at tyrosine 1472 contributes to brain injury in a rodent model of neonatal hypoxia-ischemia.
复制标题
酪氨酸1472的NR2B磷酸化在啮齿动物低氧 - 缺血症模型中有助于脑损伤。
DOI：
10.1161/strokeaha.114.006170
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发表时间：
2014-10
期刊：
影响因子：
8.3
通讯作者：
Jiang X
中科院分区：
文献类型：
--
作者：
Knox R;Brennan-Minnella AM;Lu F;Yang D;Nakazawa T;Yamamoto T;Swanson RA;Ferriero DM;Jiang X
NMDA受体的NR 2B亚基（NMDAR）在脑中被Src家族激酶Fyn磷酸化，酪氨酸（Y）1472是主要的磷酸化位点。虽然Y1472磷酸化对突触可塑性很重要，但尚不清楚它是否参与新生儿脑缺氧缺血（HI）中NMDAR介导的兴奋性毒性。本研究旨在阐明NR 2B的Y1472磷酸化在体内新生儿HI和体外NMDA介导的神经元死亡中的特定作用。使用Vannucci模型对Y1472敲入突变为苯丙氨酸（YF-KI）的新生小鼠及其野生型（WT）同窝出生小鼠进行HI。五天后，使用甲酚紫和铁染色对脑损伤进行评分。Western blotting和免疫沉淀法检测NR 2B酪氨酸磷酸化。NADPH氧化酶亚基的表达和超氧化物的产生在体内进行了测量。在原代皮层神经元中评价NMDA诱导的钙反应、超氧化物形成和细胞死亡。新生儿HI后，与WT小鼠相比，YF-KI小鼠的NADPH氧化酶亚基gp 91 phox和p47 phox的表达和超氧化物的产生减少，涉及坏死和凋亡细胞死亡的蛋白酶活性降低，脑损伤减少。在体外，YF-KI突变减少了响应于NMDA的超氧化物生成，而不影响钙积累;并抑制NMDA和谷氨酸诱导的细胞死亡。新生儿HI后Y1472处NR 2B磷酸化的上调参与了超氧化物介导的氧化应激，并导致脑损伤。
The NR2B subunit of the NMDA receptor (NMDAR) is phosphorylated by the Src family kinase Fyn in brain, with tyrosine (Y) 1472 as the major phosphorylation site. While Y1472 phosphrylation is important for synaptic plasticity, it is unknown whether it is involved in NMDAR-mediated excitotoxicity in neonatal brain hypoxiaischemia (HI). This study was designed to elucidate the specific role of Y1472 phosphorylation of NR2B in neonatal HI in vivo and in NMDA-mediated neuronal death in vitro. Neonatal mice with a knock-in mutation of Y1472 to phenylalanine (YF-KI) and their wildtype (WT) littermates were subjected to HI using the Vannucci model. Brains were scored five days later for damage using cresyl violet and iron staining. Western blotting and immunoprecipitation were performed to determine NR2B tyrosine phosphorylation. Expression of NADPH oxidase subunits and superoxide production were measured in vivo. NMDA-induced calcium response, superoxide formation and cell death were evaluated in primary cortical neurons. After neonatal HI, YF-KI mice have reduced expression of NADPH oxidase subunit gp91phox and p47phox and superoxide production, lower activity of proteases implicated in necrotic and apoptotic cell death, and less brain damage compared to the WT mice. In vitro, YF-KI mutation diminishes superoxide generation in response to NMDA without effect on calcium accumulation; and inhibits NMDA and glutamate-induced cell death. Upregulation of NR2B phosphorylation at Y1472 following neonatal HI is involved in superoxide-mediated oxidative stress and contributes to brain injury.