Calpain-Dependent ErbB4 Cleavage Is Involved in Brain Ischemia-Induced Neuronal Death
Calpain-Dependent ErbB4 Cleavage Is Involved in Brain Ischemia-Induced Neuronal Death
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钙蛋白酶依赖性 ErbB4 裂解参与脑缺血引起的神经元死亡
DOI：
10.1007/s12035-015-9275-2
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发表时间：
2016-05-01
影响因子：
5.1
通讯作者：
Li, Xiao-ming
中科院分区：
文献类型：
--
作者：
Lu, Ying-mei;Gao, Yin-ping;Li, Xiao-ming
神经调节蛋白-1β/ErbB4信号的紊乱被认为与脑缺血有关，但这种紊乱的机制很大程度上是未知的。在本研究中，我们提供的证据表明，ErbB4的降解参与了神经细胞对缺血反应的死亡。四甲基偶氮唑蓝(3-(4，5-dimethylthiazol-2-yl)-2，5-diphenyltetrazolium)比色法、膜联蛋白V/碘化丙啶流式细胞术分析和末端脱氧核苷酸转移酶(TdT)缺口末端标记(TUNEL)染色显示，应用NeuRegin-1β对缺氧缺糖诱导的神经元死亡有明显的保护作用。此外，NeuRegin-1β治疗显著减少了缺血小鼠的脑梗塞体积，而这一结果在ErbB4基因敲除小鼠中看不到。我们发现，脑缺血在体内以时间依赖的方式诱导ErbB4的降解，但不诱导ErbB2的降解。体外研究进一步表明，重组Calain以剂量依赖的方式诱导ErbB4的裂解，而Calain抑制剂显著降低OGD诱导的ErbB4的裂解。此外，转ErbB4(E872K)突变体可部分消除OGD诱导的细胞凋亡。综上所述，NeuRegin-1β以ErbB4依赖的方式发挥其神经保护作用，而在脑缺血时，Calain对ErbB4的切割有助于神经细胞死亡的级联反应。
Disturbance of neuregulin-1 beta/ErbB4 signaling is considered to be associated with brain ischemia, but the mechanisms of this disruption are largely unknown. In the present study, we provide evidence that degradation of ErbB4 is involved in neuronal cell death in response to ischemia. Our data showed that the application of neuregulin-1 beta provided significant protection against oxygen-glucose deprivation (OGD)-induced neuronal death as detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, annexin V/propidium iodide flow cytometry analysis and terminal deoxynucleotidyl transferase (TdT) dUTP nick end labeling (TUNEL) staining. Furthermore, neuregulin-1 beta treatment significantly reduced the infarct volume of ischemic mice, and this result was not seen in the ErbB4 knockout mice. We found that brain ischemia induced the breakdown of ErbB4 in a time-dependent manner in vivo, but not that of ErbB2. In vitro studies further indicated that recombinant calpain induced the cleavage of ErbB4 in a dose-dependent way, whereas the calpain inhibitor significantly reduced the OGD-induced ErbB4 breakdown. Additionally, OGD-induced apoptosis was partially abolished by transfection with the ErbB4(E872K) mutant. Taken together, neuregulin-1 beta elicits its neuroprotective effect in an ErbB4-dependent manner, and the cleavage of ErbB4 by calpain contributes to a neuronal cell death cascade during brain ischemia.