Abberant alpha-synuclein confers toxicity to neurons in part through inhibition of chaperone-mediated autophagy.
Abberant alpha-synuclein confers toxicity to neurons in part through inhibition of chaperone-mediated autophagy.
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DOI：
10.1371/journal.pone.0005515
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发表时间：
2009
期刊：
影响因子：
3.7
通讯作者：
Stefanis L
中科院分区：
文献类型：
--
作者：
Xilouri M;Vogiatzi T;Vekrellis K;Park D;Stefanis L
异常 α-突触核蛋白 (ASYN) 导致帕金森病 (PD) 神经元死亡的机制尚不确定。在分离的肝脏溶酶体中，突变的 ASYN 会损害伴侣介导的自噬 (CMA)，这是一种靶向溶酶体降解途径；然而，这是否发生在细胞环境中，以及它是否介导 ASYN 毒性，尚不清楚。我们目前已经研究了WT或突变体ASYN对神经元细胞中CMA和巨自噬的溶酶体途径的影响，并评估了它们对ASYN介导的毒性的影响。产生了表达人类 WT 和 A53T ASYN 的新型诱导型 SH-SY5Y 和 PC12 细胞系，以及两种缺乏 CMA 靶向基序的突变形式。使用腺病毒转导，这种形式也在原代皮质神经元中表达。在每种情况下，都评估了对长寿命蛋白质降解、LC3 II 水平（作为巨自噬指数）以及细胞死亡和存活的影响。在 PC12 和 SH-SY5Y 循环细胞中，A53T ASYN 的诱导引起溶酶体降解显着减少，这主要是由于 CMA 损伤。在神经元分化的 SH-SH5Y 细胞中，WT 和 A53T ASYN 诱导都会导致逐渐毒性，这部分依赖于 CMA 损伤和代偿性巨自噬诱导。在原代神经元中，WT和A53T ASYN均具有毒性，但仅在A53T ASYN的情况下，CMA功能障碍和代偿性巨自噬诱导发生并参与死亡。神经元细胞中突变型 A53T 和 WT ASYN 的表达会导致 CMA 功能障碍，进而导致巨自噬的代偿性诱导。抑制这些溶酶体效应可减轻 ASYN 毒性。因此，CMA 功能障碍介导异常的 ASYN 毒性，并且可能是 PD 和相关疾病治疗干预的目标。此外，与其他情况相比，ASYN 过度表达背景下的巨自噬诱导似乎是一种有害反应，导致神经元死亡。
The mechanisms through which aberrant α-synuclein (ASYN) leads to neuronal death in Parkinson's disease (PD) are uncertain. In isolated liver lysosomes, mutant ASYNs impair Chaperone Mediated Autophagy (CMA), a targeted lysosomal degradation pathway; however, whether this occurs in a cellular context, and whether it mediates ASYN toxicity, is unknown. We have investigated presently the effects of WT or mutant ASYN on the lysosomal pathways of CMA and macroautophagy in neuronal cells and assessed their impact on ASYN-mediated toxicity. Novel inducible SH-SY5Y and PC12 cell lines expressing human WT and A53T ASYN, as well as two mutant forms that lack the CMA-targeting motif were generated. Such forms were also expressed in primary cortical neurons, using adenoviral transduction. In each case, effects on long-lived protein degradation, LC3 II levels (as a macroautophagy index), and cell death and survival were assessed. In both PC12 and SH-SY5Y cycling cells, induction of A53T ASYN evoked a significant decrease in lysosomal degradation, largely due to CMA impairment. In neuronally differentiated SH-SH5Y cells, both WT and A53T ASYN induction resulted in gradual toxicity, which was partly dependent on CMA impairment and compensatory macroautophagy induction. In primary neurons both WT and A53T ASYN were toxic, but only in the case of A53T ASYN did CMA dysfunction and compensatory macroautophagy induction occur and participate in death. Expression of mutant A53T, and, in some cases, WT ASYN in neuronal cells leads to CMA dysfunction, and this in turn leads to compensatory induction of macroautophagy. Inhibition of these lysosomal effects mitigates ASYN toxicity. Therefore, CMA dysfunction mediates aberrant ASYN toxicity, and may be a target for therapeutic intervention in PD and related disorders. Furthermore, macroautophagy induction in the context of ASYN over-expression, in contrast to other settings, appears to be a detrimental response, leading to neuronal death.
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影响因子：
168.9
作者：
Chartier-Harlin, MC;Kachergus, J;Destée, A
通讯作者：
Destée, A
影响因子：
168.9
作者：
Ibáñez, P;Bonnet, AM;Brice, A
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作者：
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Kordower, Jeffrey H.
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作者：
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影响因子：
3
作者：
Burke, W. J.
通讯作者：
Burke, W. J.