Holo-APP and G-protein-mediated signaling are required for sAPPα-induced activation of the Akt survival pathway.
Holo-APP and G-protein-mediated signaling are required for sAPPα-induced activation of the Akt survival pathway.
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DOI：
10.1038/cddis.2014.352
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发表时间：
2014-08-28
影响因子：
9
通讯作者：
中科院分区：
文献类型：
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越来越多的证据表明，在大脑衰老过程中，生理性淀粉样前体蛋白（APP）功能的丧失导致神经元可塑性降低，突触信号减少，神经元对细胞应激的易感性增强。本文研究了可溶性APP外结构域sAPPα（可溶性APPα）的神经保护功能，该结构域是由α-分泌酶沿非淀粉样变性途径裂解APP产生的。重组sAPPα保护原代海马神经元和SH-SY5Y神经母细胞瘤细胞免于营养因子剥夺引起的细胞死亡。我们发现，这种保护作用在app敲除动物和app缺失的SH-SY5Y细胞的神经元中被取消，但在app样蛋白1-和2- （APLP1和APLP2）缺失的细胞中没有，这表明膜结合的holo-APP的表达是sappα依赖的神经保护所必需的。营养因子剥夺降低了Akt存活通路的活性。值得注意的是，重组sAPPα和APP-E1结构域都能刺激野生型（wt）成纤维细胞、SH-SY5Y细胞和神经元中Akt的活性，但在app缺陷型神经元或成纤维细胞中却不能。在营养因子和葡萄糖剥夺的wt小鼠器官型（海马）切片培养中，ADAM10（一种崩解素和金属蛋白酶结构域蛋白10）抑制剂GI254023X加重了神经元死亡。GI254023X增强细胞死亡的作用可通过外源sAPPα完全恢复。有趣的是，缺乏APP胞内区c端YENPTY基序的APP-ΔCT15小鼠的神经元中，sapp α依赖性Akt诱导不受影响。相比之下，在APP c端缺乏g蛋白相互作用基序的APP突变细胞中，通过阻断g蛋白依赖的百日咳毒素信号通路，sapp α依赖的Akt激活被完全消除。总的来说，我们的数据为APP在对抗神经毒性应激中的生理作用提供了新的机制见解：他们表明，细胞表面APP通过g蛋白偶联激活Akt通路介导sapp α-诱导的神经保护。
Accumulating evidence indicates that loss of physiologic amyloid precursor protein (APP) function leads to reduced neuronal plasticity, diminished synaptic signaling and enhanced susceptibility of neurons to cellular stress during brain aging. Here we investigated the neuroprotective function of the soluble APP ectodomain sAPPα (soluble APPα), which is generated by cleavage of APP by α-secretase along the non-amyloidogenic pathway. Recombinant sAPPα protected primary hippocampal neurons and SH-SY5Y neuroblastoma cells from cell death induced by trophic factor deprivation. We show that this protective effect is abrogated in neurons from APP-knockout animals and APP-depleted SH-SY5Y cells, but not in APP-like protein 1- and 2- (APLP1 and APLP2) depleted cells, indicating that expression of membrane-bound holo-APP is required for sAPPα-dependent neuroprotection. Trophic factor deprivation diminished the activity of the Akt survival pathway. Strikingly, both recombinant sAPPα and the APP-E1 domain were able to stimulate Akt activity in wild-type (wt) fibroblasts, SH-SY5Y cells and neurons, but failed to rescue in APP-deficient neurons or fibroblasts. The ADAM10 (a disintegrin and metalloproteinase domain-containing protein 10) inhibitor GI254023X exacerbated neuron death in organotypic (hippocampal) slice cultures of wt mice subjected to trophic factor and glucose deprivation. This cell death-enhancing effect of GI254023X could be completely rescued by applying exogenous sAPPα. Interestingly, sAPPα-dependent Akt induction was unaffected in neurons of APP-ΔCT15 mice that lack the C-terminal YENPTY motif of the APP intracellular region. In contrast, sAPPα-dependent rescue of Akt activation was completely abolished in APP mutant cells lacking the G-protein interaction motif located in the APP C-terminus and by blocking G-protein-dependent signaling with pertussis toxin. Collectively, our data provide new mechanistic insights into the physiologic role of APP in antagonizing neurotoxic stress: they suggest that cell surface APP mediates sAPPα-induced neuroprotection via G-protein-coupled activation of the Akt pathway.
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影响因子：
4.8
作者：
Adlerz, Linda;Holback, Sofia;Iverfeldt, Kerstin
通讯作者：
Iverfeldt, Kerstin
影响因子：
11.4
作者：
Leyssen, M;Ayaz, D;Hassan, BA
通讯作者：
Hassan, BA
影响因子：
48
作者：
Anliker, Brigitte;Abel, Tobias;Buchholz, Christian J.
通讯作者：
Buchholz, Christian J.
影响因子：
4.8
作者：
Gralle, Matthias;Botelho, Michelle Gralle;Wouters, Fred S.
通讯作者：
Wouters, Fred S.
DOI：
10.1523/jneurosci.5433-11.2012
发表时间：
2012-02-01
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
--
作者：
Deyts C;Vetrivel KS;Das S;Shepherd YM;Dupré DJ;Thinakaran G;Parent AT
通讯作者：
Parent AT