Role of Matrix Metalloproteinase 3-mediated α-Synuclein Cleavage in Dopaminergic Cell Death
Role of Matrix Metalloproteinase 3-mediated α-Synuclein Cleavage in Dopaminergic Cell Death
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DOI：
10.1074/jbc.m111.222430
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发表时间：
2011-04-22
影响因子：
4.8
通讯作者：
Kim, Yoon-Seong
中科院分区：
文献类型：
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作者：
Choi, Dong-Hee;Kim, Youn-Jung;Kim, Yoon-Seong
有证据表明，α-突触核蛋白的C-末端截短与α-突触核蛋白的聚集在帕金森病（PD）中同样重要。我们以前的研究结果表明，内肽酶，基质金属蛋白酶-3（MMP-3），诱导和激活多巴胺能（DA）细胞在应激条件下。在这里，我们报告说，MMP 3切割α-突触核蛋白在体外和体内，α-突触核蛋白和MMP 3共定位于路易体（LB）在PD患者的死后大脑。将α-突触核蛋白与MMP 3的催化结构域（cMMP 3）孵育导致产生几种肽，并且WT α-突触核蛋白（WTsyn）和A53 T突变体（A53 Tsyn）的肽谱不同。使用质谱和N-末端测定的组合分析显示，MMP 3产生氨基酸1-78、1-91和1-93的C-末端截短肽，并且A53 Tsyn产生显著更高量的这些肽。在N27 DA细胞中，在氧化应激和RNA干扰下检测到类似大小的肽，以敲低MMP 3-减弱肽的产生。cMMP 3与WTsyn或A53 Tsyn的共过表达导致Triton X-100不溶性聚集体的减少和原纤维样小聚集体的增加。此外，1-93-氨基酸肽在黑质中的过度表达导致DA神经元损失，而没有LB样聚集体形成。结果强烈表明，MMP 3消化DA神经元中的α-突触核蛋白通过调节α-突触核蛋白的聚集、LB形成和神经毒性在PD的进展中起关键作用。
Evidence suggests that the C-terminal truncation of alpha-synuclein is equally important as aggregation of alpha-synuclein in Parkinson disease (PD). Our previous results showed that an endopeptidase, matrix metalloproteinase-3 (MMP3), was induced and activated in dopaminergic (DA) cells upon stress conditions. Here, we report that MMP3 cleaved alpha-synuclein in vitro and in vivo and that alpha-synuclein and MMP3 were co-localized in Lewy bodies (LB) in the postmortem brains of PD patients. Incubation of alpha-synuclein with the catalytic domain of MMP3 (cMMP3) resulted in generation of several peptides, and the peptide profiles of WT alpha-synuclein (WTsyn) and A53T mutant (A53Tsyn) were different. Combined analysis using mass spectrometry and N-terminal determination revealed that MMP3 generated C-terminally truncated peptides of amino acids 1-78, 1-91, and 1-93 and that A53Tsyn produced significantly higher quantities of these peptides. Similar sizes of peptides were detected in N27 DA cells under oxidative stress and RNA interference to knock down MMP3-attenuated peptide generation. Co-overexpression of cMMP3 with either WTsyn or A53Tsyn led to a reduction in Triton X-100-insoluble aggregates and an increase in protofibril-like small aggregates. In addition, overexpression of the 1-93-amino acid peptide in the substantia nigra led to DA neuronal loss without LB-like aggregate formation. The results strongly indicate that MMP3 digestion of alpha-synuclein in DA neurons plays a pivotal role in the progression of PD through modulation of alpha-synuclein in aggregation, LB formation, and neurotoxicity.