BACKGROUND & AIMS: :Protein fibrils drive the onset and progression of many diseases in a prion-like manner, i.e. they transcellular propagate through the extracellular space to health cells to initiate toxic aggregation as seeds. The conversion of native α-synuclein into filamentous aggregates in Lewy bodies is a hallmark of Parkinson's disease (PD). Copper and iron ions accumulate in PD brains, however, whether they influence the prion-like propagation of α-synuclein remain unclear. Here, we reported that copper/iron ions accelerate prion-like propagation of α-synuclein fibrils by promoting cellular internalization of α-synuclein fibrils, intracellular α-synuclein aggregation and the subsequent release of mature fibrils to the extracellular space to induce further propagation. Mechanistically, copper/iron ions enhanced α-synuclein fibrils internalization was mediated by negatively charged membrane heparan sulfate proteoglycans (HSPGs). α-Synuclein fibrils formed in the presence of copper/iron ions were more cytotoxic, causing increased ROS production, cell apoptosis, and shortened the lifespan of a C. elegans PD model overexpressing human α-synuclein. Notably, these deleterious effects were ameliorated by two clinically used chelators, triethylenetetramine and deferiprone. Together, our results suggest a new role for heavy metal ions, e.g. copper and iron, in the pathogenesis of PD through accelerating prion-like propagation of α-synuclein fibrils.

背景与目标： : 蛋白质原纤维以类似朊病毒的方式驱动许多疾病的发生和发展，即它们通过细胞外空间跨细胞传播到健康细胞，以启动作为种子的毒性聚集。路易体中天然 α-突触核蛋白转化为丝状聚集体是帕金森氏病 (PD) 的标志。铜和铁离子在PD大脑中积累，但是，它们是否影响 α-突触核蛋白的朊病毒样传播尚不清楚。在这里，我们报道了铜/铁离子通过促进 α-突触核蛋白原纤维的细胞内在化，细胞内 α-突触核蛋白聚集以及随后成熟原纤维释放到细胞外空间以诱导进一步繁殖来加速 α-突触核蛋白原纤维的病毒样传播。从机理上讲，铜/铁离子增强了 α-突触核蛋白原纤维的内在化是由带负电的膜硫酸乙酰肝素蛋白聚糖 (hspg) 介导的。在铜/铁离子存在下形成的 α-突触核蛋白原纤维更具细胞毒性，导致ROS产生增加，细胞凋亡并缩短了过度表达人类 α-突触核蛋白的秀丽隐杆线虫PD模型的寿命。值得注意的是，两种临床使用的螯合剂三乙烯四胺和去铁酮改善了这些有害作用。总之，我们的结果表明，通过加速 α-突触核蛋白原纤维的朊病毒样传播，重金属离子 (例如铜和铁) 在PD的发病机理中起新作用。

BACKGROUND & AIMS: BACKGROUND:Abnormal α-synuclein aggregation and deposition is the pathological hallmark of Parkinson's disease (PD) and dementia with Lewy bodies (DLB), but is also found in Alzheimer disease (AD). Therefore, there is a gaining interest in α-synuclein in cerebrospinal fluid (CSF) as potential biomarker for these neurodegenerative diseases. To broaden the available choices of α-synuclein measurement in CSF, we developed and validated a new assay for detecting total α-synuclein. METHODS:This novel ELISA uses commercially available antibodies and is based on electrochemiluminescence technology. The assay protocol is straightforward, with short and simple incubation steps, and requires only small amounts of CSF. We validated this assay for precision, parallelism, dilution linearity, specificity, and spike recovery. We further compared it to the newly validated α-synuclein assay from BioLegend by analyzing a set of 50 CSF samples with both assays. RESULTS:The new assay quantifies α-synuclein in CSF with a lower limit of detection of 36.3 pg/mL and shows no cross-reactivity with human β- and γ-synuclein. Results of dilution linearity, parallelism, spike recovery, and precision classify this assay as well suited for α-synuclein detection in human CSF samples. CONCLUSIONS:We present a novel assay based on freely available components to quantify total α-synuclein in CSF as an additional method for α-synuclein as a biomarker in neurodegenerative diseases. The assay convinces with its simple and convenient protocol paired with high sensitivity.

背景与目标：

BACKGROUND & AIMS: :We recently reported that Alzheimer's disease (AD) with amygdala Lewy bodies (ALB) is a distinct form of alpha-synucleinopathy that occurs in advanced AD. In AD/ALB the alpha-synuclein pathology correlated with tau pathology, but not amyloid plaques, and there was often co-localization of tau and alpha-synuclein in the same neuron. Given the anatomical connectivity of the anterior olfactory nucleus and the amygdala, which receives axonal projections from the olfactory bulb, we hypothesized that there might be a relationship between tau and alpha-synuclein pathology in the olfactory bulb and the amygdala in AD. We screened for alpha-synuclein pathology in the olfactory bulb in AD with and without ALB, and investigated its relationship with tau pathology. In 38 of 41 (93%) AD/ALB cases and 4 of 21 (19%) AD cases without ALB (AD/non-ALB), alpha-synuclein pathology was detected in the olfactory bulb. Double immunolabeling at the light and electron microscopic levels revealed co-localization of tau and alpha-synuclein in the olfactory bulb neurons and neurites. The severity of tau pathology correlated with alpha-synuclein pathology in the olfactory bulb. In addition, alpha-synuclein pathology in the olfactory bulb correlated with alpha-synuclein pathology in amygdala. Tau pathology was greater in both the olfactory bulb and amygdala in AD/ALB than in AD/non-ALB, but there was no difference in tau pathology between the two groups in other brain regions assessed. The present study shows that in AD/ALB, the olfactory bulb is nearly equally vulnerable to tau and alpha-synuclein pathology as the amygdala and suggests that neurodegeneration in these two anatomical regions is linked.

背景与目标： : 我们最近报道了患有杏仁核路易体 (ALB) 的阿尔茨海默氏病 (AD) 是发生在晚期AD中的一种独特形式的 α 突触核蛋白病。在AD/ALB中，α-突触核蛋白病理与tau病理相关，但与淀粉样斑块无关，并且tau和 α-突触核蛋白经常在同一神经元中共同定位。考虑到前嗅神经核和杏仁核的解剖连接，杏仁核从嗅球接收轴突投射，我们假设嗅球和AD杏仁核中的tau和 α-突触核蛋白病理之间可能存在关系。我们在有或没有ALB的AD嗅球中筛选了 α-突触核蛋白病理学，并研究了其与tau病理学的关系。在41例 (93% 例) AD/ALB病例中的38例和无ALB (AD/非ALB) 的21例 (19% 例) AD病例中的4例中，在嗅球中检测到 α-突触核蛋白病理。光镜和电子显微镜下的双重免疫标记显示tau和 α-突触核蛋白在嗅球神经元和神经突中的共定位。tau病理的严重程度与嗅球中的 α-突触核蛋白病理相关。此外，嗅球中的 α-突触核蛋白病理与杏仁核中的 α-突触核蛋白病理相关。AD/ALB中嗅球和杏仁核的Tau病理学均高于AD/非ALB，但在评估的其他大脑区域中，两组之间的tau病理学没有差异。本研究表明，在AD/ALB中，嗅球与杏仁核几乎同样容易受到tau和 α-突触核蛋白病理学的影响，并表明这两个解剖区域的神经变性是相关的。

BACKGROUND & AIMS: :Parkinson's disease and some other neurodegenerative disorders are associated with a protein that can aggregate and form fibrils called alpha-synuclein. Like many other proteins associated with neurodegenerative disorders, this protein has no known function, and the mechanism by which it could cause diseases is poorly defined. It was recently suggested that it binds copper. This review assesses what is known about alpha-synuclein and its interaction with metals.

背景与目标： 帕金森氏病和其他一些神经退行性疾病与一种蛋白质有关，这种蛋白质可以聚集并形成称为 α-突触核蛋白的原纤维。与许多其他与神经退行性疾病相关的蛋白质一样，这种蛋白质没有已知的功能，并且它可能引起疾病的机制尚不明确。最近有人建议它结合铜。这篇评论评估了有关 α-突触核蛋白及其与金属相互作用的已知信息。

BACKGROUND & AIMS: :Alpha-synuclein is a major component of intraneuronal protein aggregates constituting a distinctive feature of Parkinson disease. To date, fluorescence imaging of dynamic processes leading to such amyloid deposits in living cells has not been feasible. To address this need, we generated a recombinant alpha-synuclein (alpha-synuclein-C4) bearing a tetracysteine target for fluorogenic biarsenical compounds. The biophysical, biochemical and aggregation properties of alpha-synuclein-C4 matched those of the wild-type protein in vitro and in living cells. We observed aggregation of alpha-synuclein-C4 transfected or microinjected into cells, particularly under oxidative stress conditions. Fluorescence resonance energy transfer (FRET) between FlAsH and ReAsH confirmed the close association of fibrillized alpha-synuclein-C4 molecules. Alpha-synuclein-C4 offers the means for directly probing amyloid formation and interactions of alpha-synuclein with other proteins in living cells, the response to cellular stress and screening drugs for Parkinson disease.

背景与目标： : α-突触核蛋白是构成帕金森病独特特征的神经内蛋白聚集体的主要成分。迄今为止，对导致活细胞中此类淀粉样蛋白沉积的动态过程进行荧光成像是不可行的。为了满足这一需求，我们产生了带有用于荧光二砷化合物的四半胱氨酸靶标的重组 α-突触核蛋白 (alpha-synuclein-C4)。alpha-synuclein-C4的生物物理，生化和聚集特性与体外和活细胞中的野生型蛋白质相匹配。我们观察到转染或微注入细胞的alpha-synuclein-C4聚集，特别是在氧化应激条件下。闪光和ReAsH之间的荧光共振能量转移 (FRET) 证实了纤化alpha-synuclein-C4分子的紧密结合。Alpha-synuclein-C4提供了直接探测活细胞中淀粉样蛋白的形成以及 α-突触核蛋白与其他蛋白质的相互作用，对细胞应激的反应以及筛选帕金森病药物的手段。

BACKGROUND & AIMS: :Although the function of biopolymer hydrogels in nature depends on structural anisotropy at mesoscopic length scales, the self-assembly of such anisotropic structures in vitro is challenging. Here we show that fibrils of the protein α-synuclein spontaneously self-assemble into structurally anisotropic hydrogel particles. While the fibrils in the interior of these supra-fibrillar aggregates (SFAs) are randomly oriented, the fibrils in the periphery prefer to cross neighboring fibrils at high angles. This difference in organization coincides with a significant difference in polarity of the environment in the central and peripheral parts of the SFA. We rationalize the structural anisotropy of SFAs in the light of the observation that αS fibrils bind a substantial amount of counterions. We propose that, with the progress of protein polymerization into fibrils, this binding of counterions changes the ionic environment which triggers a change in fibril organization resulting in anisotropy in the architecture of hydrogel particles.

背景与目标： : 尽管生物聚合物水凝胶在自然界中的功能取决于介观长度尺度上的结构各向异性，但这种各向异性结构在体外的自组装具有挑战性。在这里，我们显示蛋白质 α-突触核蛋白的原纤维自发自组装成结构各向异性的水凝胶颗粒。虽然这些超原纤维聚集体 (SFAs) 内部的原纤维是随机定向的，但外围的原纤维更喜欢以大角度交叉相邻的原纤维。组织上的这种差异与SFA中央和外围部分环境极性的显着差异相吻合。根据 α s原纤维结合大量抗衡离子的观察，我们合理化了SFAs的结构各向异性。我们建议，随着蛋白质聚合成原纤维的过程，抗衡离子的这种结合会改变离子环境，从而触发原纤维组织的变化，从而导致水凝胶颗粒结构的各向异性。

BACKGROUND & AIMS: :Recent evidence suggests that gamma-synuclein is abnormally expressed in a high percentage of tumor tissues of diversified cancer types, but rarely expressed in tumor-matched non-neoplastic adjacent tissues (NNAT). The molecular mechanism of CpG island demethylation may underlie aberrant gamma-synuclein expression. To fully understand the roles of aberrant gamma-synuclein expression and demethylation in the development of colorectal cancer (CRC), we examined the expression and methylation status of gamma-synuclein in 67 CRC samples, 30 NNAT samples, and five CRC cell lines as well. By using reverse transcription-polymerase chain reaction (RT-PCR), western blot, and immunohistochemistry analyses, gamma-synuclein expression was detected in both HT-29 and HCT116 cells, and was much higher in CRC samples than in NNAT samples (P < 0.05). The demethylating agent, 5-aza-2 cent-deoxycytidine, can induce re-expression of gamma-synuclein in COLO205, LoVo, and SW480 cells. Unmethylated gamma-synuclein alleles were detected in HT-29, HCT116, and LoVo cells by nested methylation-specific PCR, and the demethylated status of gamma-synuclein was much higher in CRC samples than in NNAT samples by real-time quantitative methylation-specific PCR (P < 0.05). The results of genomic bisulfite DNA sequencing further confirmed that the aberrant gamma-synuclein expression in CRC was primarily attributed to the demethylation of CpG island. The protein expression and demethylation status of gamma-synuclein in 67 CRC samples correlated with clinical stage, lymph node involvement, and distant metastasis. These findings suggest an involvement of aberrant gamma-synuclein expression and demethylation in progression of CRC, especially in advanced stages.

背景与目标： : 最近的证据表明，γ-突触核蛋白在多种癌症类型的高百分比肿瘤组织中异常表达，但在肿瘤匹配的非肿瘤性邻近组织 (NNAT) 中很少表达。CpG岛去甲基化的分子机制可能是异常 γ-突触核蛋白表达的基础。为了充分了解异常 γ-突触核蛋白表达和去甲基化在结直肠癌 (CRC) 发生中的作用，我们检查了67份CRC样品，30份NNAT样品和5种CRC细胞系中 γ-突触核蛋白的表达和甲基化状态。通过使用逆转录-聚合酶链反应 (rt-pcr)，western blot和免疫组织化学分析，在HT-29和HCT116细胞中均检测到 γ-突触核蛋白表达，并且在CRC样品中比在nnnat样品中高得多 (P <0.05)。脱甲基剂5-aza-2 cent-脱氧胞苷可以诱导COLO205，LoVo和SW480细胞中 γ-突触核蛋白的重新表达。通过巢式甲基化特异性PCR在HT-29、HCT116和LoVo细胞中检测到未甲基化的 γ-突触核蛋白等位基因，并且通过实时定量甲基化特异性PCR，CRC样品中 γ-突触核蛋白的去甲基化状态远高于NNAT样品 (P <0.05)。基因组亚硫酸氢盐DNA测序的结果进一步证实，CRC中异常的 γ-突触核蛋白表达主要归因于CpG岛的去甲基化。67例CRC样本中 γ-突触核蛋白的蛋白表达和去甲基化状态与临床分期，淋巴结受累和远处转移有关。这些发现表明，异常的 γ-突触核蛋白表达和去甲基化参与了CRC的进展，尤其是在晚期。

BACKGROUND & AIMS: :Parkinson's disease is a progressive neuropathological disorder that belongs to the class of synucleinopathies, in which the protein alpha-synuclein is found at abnormally high concentrations in affected neurons. Its hallmark are intracellular inclusions called Lewy bodies and Lewy neurites. We here report the structure of cytotoxic alpha-synuclein fibrils (residues 1-121), determined by cryo-electron microscopy at a resolution of 3.4 Å. Two protofilaments form a polar fibril composed of staggered β-strands. The backbone of residues 38 to 95, including the fibril core and the non-amyloid component region, are well resolved in the EM map. Residues 50-57, containing three of the mutation sites associated with familial synucleinopathies, form the interface between the two protofilaments and contribute to fibril stability. A hydrophobic cleft at one end of the fibril may have implications for fibril elongation, and invites for the design of molecules for diagnosis and treatment of synucleinopathies.

背景与目标： : 帕金森氏病是一种进行性神经病理疾病，属于突触核蛋白病，其中在受影响的神经元中以异常高浓度发现蛋白质 α-突触核蛋白。它的标志是称为路易体和路易神经突的细胞内包裹体。我们在这里报告细胞毒性 α-突触核蛋白原纤维 (残基1-121) 的结构，该结构通过冷冻电子显微镜以3.4的分辨率确定。两条原丝形成由交错的 β 链组成的极性原纤维。残基38至95的主链，包括原纤维核和非淀粉样成分区域，在EM图中得到很好的解析。残基50-57 (包含与家族性突触核蛋白病相关的三个突变位点) 形成了两个原丝之间的界面，并有助于原纤维的稳定性。原纤维一端的疏水裂隙可能会影响原纤维的伸长，并邀请设计用于诊断和治疗突触核蛋白病的分子。

BACKGROUND & AIMS: :The aggregation of α-synuclein, an intrinsically disordered protein that is highly abundant in neurons, is closely associated with the onset and progression of Parkinson's disease. We have shown previously that the aminosterol squalamine can inhibit the lipid induced initiation process in the aggregation of α-synuclein, and we report here that the related compound trodusquemine is capable of inhibiting not only this process but also the fibril-dependent secondary pathways in the aggregation reaction. We further demonstrate that trodusquemine can effectively suppress the toxicity of α-synuclein oligomers in neuronal cells, and that its administration, even after the initial growth phase, leads to a dramatic reduction in the number of α-synuclein inclusions in a Caenorhabditis elegans model of Parkinson's disease, eliminates the related muscle paralysis, and increases lifespan. On the basis of these findings, we show that trodusquemine is able to inhibit multiple events in the aggregation process of α-synuclein and hence to provide important information about the link between such events and neurodegeneration, as it is initiated and progresses. Particularly in the light of the previously reported ability of trodusquemine to cross the blood-brain barrier and to promote tissue regeneration, the present results suggest that this compound has the potential to be an important therapeutic candidate for Parkinson's disease and related disorders.

背景与目标： : α-突触核蛋白 (一种内在无序的蛋白质，在神经元中含量很高) 的聚集与帕金森氏病的发生和发展密切相关。我们之前已经证明，氨基甾醇角鲨胺可以抑制脂质诱导的 α-突触核蛋白聚集的引发过程，并且我们在此报告相关的化合物trodusquemine不仅能够抑制该过程，而且能够抑制原纤维依赖性的引发过程。聚集反应。我们进一步证明，trodusquemine可以有效地抑制神经元细胞中 α-突触核蛋白低聚物的毒性，即使在最初的生长期之后，其给药也会导致秀丽隐杆线虫模型中 α-突触核蛋白内含物的数量急剧减少。帕金森氏病，消除了相关的肌肉麻痹，延长寿命。基于这些发现，我们表明trodusquemine能够抑制 α-突触核蛋白聚集过程中的多个事件，从而提供有关此类事件与神经退行性变之间联系的重要信息，因为它是开始和发展的。特别是考虑到先前报道的trodusquemine穿越血脑屏障并促进组织再生的能力，本研究结果表明，该化合物有可能成为帕金森氏病和相关疾病的重要治疗候选者。

BACKGROUND & AIMS: OBJECTIVE:The aim of this study was to analyze autonomic function and cardiac sympathetic innervation in symptomatic and asymptomatic carriers of the E46K alpha-synuclein gene (SNCA) mutation. PATIENTS AND METHODS:Autonomic function tests were performed in six patients, four of whom were symptomatic carriers (ages: 46, 59, 52 and 28-years) and two who were asymptomatic carriers (ages: 52 and 29 years). Autopsy studies were performed on an additional two symptomatic carriers not eligible for autonomic testing. Patients completed the SCOPA autonomic questionnaire, and underwent the head-up tilt test accompanied by measurements of plasma norepinephrine. Valsalva maneuver and deep breathing tests, along with recording of sympathetic skin response (SSR) and cardiac MIBG scintigraphy were carried out. Myocardial tissue sections removed from the two autopsied cases were subjected to routine histological staining and immunohistochemical processing with monoclonal antibodies against tyrosine hydroxylase and alpha-synuclein. RESULTS:Both the four symptomatic and the older asymptomatic carriers reported abnormalities in the SCOPA questionnaire and had markedly diminished cardiac MIBG uptake. Plasma norepinephrine in the supine and tilted positions was normal in all subjects. Only one patient had significant orthostatic hypotension. There was a complete absence of tyrosine hydroxylase immunostaining in the myocardium of the two autopsied cases. INTERPRETATION:We have found imaging and histological evidence of cardiac sympathetic denervation in symptomatic and asymptomatic carriers of the E46K alpha-synuclein gene mutation. The sympathetic denervation appears to be organ-specific, with selective affectation of the heart given that plasma norepinephrine levels and blood pressure were normal.

背景与目标：

BACKGROUND & AIMS: alpha-Synuclein (alpha S) is a pre-synaptic protein that has been implicated as a possible causative agent in the pathogenesis of Parkinson's disease (PD). Two autosomal dominant missense mutations in the alpha S gene are associated with early onset PD. Because alpha S is found in an aggregated fibrillar form in the Lewy body deposits characteristic of Parkinson's patients, aggregation of the protein is believed to be related to its involvement in the disease process. The wild type (WT) and early onset mutants A30P and A53T display diverse in vitro aggregation kinetics even though the gross physicochemical and morphological properties of the mutants are highly similar. We used high resolution solution NMR spectroscopy to compare the structural and dynamic properties of the A53T and A30P mutants with those of WT alpha S in the free state. We found that the A30P mutation disrupts a region of residual helical structure that exists in the WT protein, whereas the A53T mutation results in a slight enhancement of a small region around the site of mutation with a preference for extended conformations. Based on these results and on the anticipated effects of these mutations on elements of secondary structure, we proposed a model of how these two PD-linked mutations influence alpha S fibril formation that is consistent with the documented differences in the fibrillization kinetics of the two mutants.

背景与目标： Α-突触核蛋白 (alpha S) 是一种突触前蛋白，已被认为是帕金森氏病 (PD) 发病机理中的可能病原体。alpha S基因中的两个常染色体显性遗传错义突变与早发性PD有关。由于在帕金森氏病患者的路易体沉积物中以聚集的原纤维形式发现了alpha S，因此据信该蛋白的聚集与其参与疾病过程有关。野生型 (WT) 和早发突变体A30P和A53T表现出不同的体外聚集动力学，即使突变体的总体理化和形态特性非常相似。我们使用高分辨率溶液NMR光谱比较了A53T和A30P突变体与自由状态下WT α S的结构和动力学特性。我们发现A30P突变破坏了WT蛋白中存在的残余螺旋结构区域，而A53T突变导致突变位点周围的小区域略有增强，并倾向于扩展构象。基于这些结果以及这些突变对二级结构元素的预期影响，我们提出了这两个PD连锁突变如何影响 α S原纤维形成的模型，该模型与已记录的两个突变体的纤维化动力学差异一致。

BACKGROUND & AIMS: :In the last decades, a series of compounds, including quinones and polyphenols, has been described as having anti-fibrillogenic action on α-synuclein (α-syn) whose aggregation is associated to the pathogenesis of Parkinson's disease (PD). Most of these molecules act as promiscuous anti-amyloidogenic agents, interacting with the diverse amyloidogenic proteins (mostly unfolded) through non-specific hydrophobic interactions. Herein we investigated the effect of the vitamins K (phylloquinone, menaquinone and menadione), which are 1,4-naphthoquinone (1,4-NQ) derivatives, on α-syn aggregation, comparing them with other anti-fibrillogenic molecules such as quinones, polyphenols and lipophilic vitamins. Vitamins K delayed α-syn fibrillization in substoichiometric concentrations, leading to the formation of short, sheared fibrils and amorphous aggregates, which are less prone to produce leakage of synthetic vesicles. In seeding conditions, menadione and 1,4-NQ significantly inhibited fibrils elongation, which could be explained by their ability to destabilize preformed fibrils of α-syn. Bidimensional NMR experiments indicate that a specific site at the N-terminal α-syn (Gly31/Lys32) is involved in the interaction with vitamins K, which is corroborated by previous studies suggesting that Lys is a key residue in the interaction with quinones. Together, our data suggest that 1,4-NQ, recently showed up by our group as a potential scaffold for designing new monoamine oxidase inhibitors, is also capable to modulate α-syn fibrillization in vitro.

背景与目标： : 在过去的几十年中，一系列化合物 (包括醌和多酚) 被描述为对 α-突触核蛋白 (α-syn) 具有抗原纤维生成作用，其聚集与帕金森氏病 (PD) 的发病机理有关。这些分子中的大多数充当混杂的抗淀粉样蛋白生成剂，通过非特异性疏水相互作用与多种淀粉样蛋白 (大部分未折叠) 相互作用。在本文中，我们研究了1,4-萘醌 (1,4-nq) 衍生物的维生素k (叶绿醌，甲萘醌和甲萘醌) 对 α-syn聚集的影响，并将其与其他抗原纤维生成分子进行了比较例如醌，多酚和亲脂性维生素。维生素k在亚化学计量的浓度下延迟了 α-syn的结晶化，导致形成短的剪切原纤维和无定形聚集体，不易产生合成囊泡的泄漏。在播种条件下，甲萘醌和1,4-nq显着抑制原纤维的伸长，这可以用它们破坏 α-syn的预制原纤维的能力来解释。二维NMR实验表明，N末端 α-syn (Gly31/Lys32) 的特定位点参与了与维生素k的相互作用，这已被先前的研究证实，表明Lys是与醌相互作用的关键残基。总之，我们的数据表明，我们小组最近发现的1,4-nq是设计新的单胺氧化酶抑制剂的潜在支架，它也能够在体外调节 α-合成纤维化。

BACKGROUND & AIMS: :Parkinson's disease is the second most common neurodegenerative disease, after Alzheimer's disease, among the aging human population. The main symptoms of Parkinson's disease such as tremor and movement disabilities are the result of degeneration of dopaminergic neurons in substantia nigra pars compacta. The widely-accepted subcellular factor which underlies Parkinson's disease neuropathology is the presence of Lewy bodies with characteristic inclusions of aggregated alpha-synuclein. This small soluble protein has been implicated in a range of interactions with phospholipid membranes and free fatty acids. The precise biological function of this protein is, however, still under investigation. Here we review the evidence linking alpha-synuclein, lipid metabolism, fatty acid oxidation, mitochondrial damage and Parkinson's disease. We propose that association of alpha-synuclein with oxidized lipid metabolites can lead to mitochondrial dysfunction in turn leading to dopaminergic neuron death and thus to Parkinson's disease.

背景与目标： : 帕金森氏病是仅次于阿尔茨海默氏病的第二大最常见的神经退行性疾病，在人口老龄化中。帕金森病的主要症状如震颤和运动障碍是黑质致密部多巴胺能神经元变性的结果。帕金森氏病神经病理学基础的广泛接受的亚细胞因子是路易体的存在，其中包含聚集的 α-突触核蛋白。这种小的可溶性蛋白与磷脂膜和游离脂肪酸的一系列相互作用有关。然而，这种蛋白质的精确生物学功能仍在研究中。在这里，我们回顾了将 α-突触核蛋白，脂质代谢，脂肪酸氧化，线粒体损伤和帕金森氏病联系起来的证据。我们建议，α-突触核蛋白与氧化脂质代谢物的结合会导致线粒体功能障碍，进而导致多巴胺能神经元死亡，从而导致帕金森氏病。

BACKGROUND & AIMS: :Protein aggregation plays a central role in numerous neurodegenerative diseases. The key proteins in these diseases are of significant importance, but their investigation can be challenging due to unique properties of protein misfolding and oligomerization. Alpha-synuclein protein (α-Syn) is the predominant component of Lewy Bodies in Parkinson's disease (PD) and is a member of this class of proteins. Many α-Syn studies are limited by the inability to separate various monomeric, oligomeric, and fibrillar forms of the protein from heterogeneous mixtures. This Editorial Highlight summarizes the impact of a study published in the current issue of Journal of Neurochemistry, in which Lashuel and colleagues developed a simple, rapid centrifugation- and filter-based method for separating, isolating, and quantifying different forms of α-Syn. The researchers used electron microscopy, SDS-PAGE, circular dichroism, and protein assays to carefully validate the method and quantitate α-Syn yields and loss. The publication of this new method will not only aid in future studies of α-Syn, but will likely extend to other proteins that underlie a variety of neurodegenerative diseases.

背景与目标： : 蛋白质聚集在许多神经退行性疾病中起着核心作用。这些疾病中的关键蛋白质非常重要，但是由于蛋白质错误折叠和低聚的独特特性，它们的研究可能具有挑战性。Α-突触核蛋白 (α-Syn) 是帕金森氏病 (PD) 中路易体的主要成分，并且是此类蛋白质的成员。许多 α-Syn研究受到无法从异质混合物中分离蛋白质的各种单体，寡聚和原纤维形式的限制。这篇社论重点总结了本期《神经化学杂志》上发表的一项研究的影响，其中Lashuel及其同事开发了一种简单，快速的基于离心和过滤器的方法，用于分离，分离和定量不同形式的 α-Syn。研究人员使用电子显微镜，sdds-PAGE，圆二色性和蛋白质测定法来仔细验证该方法并定量 α-Syn的产量和损失。这种新方法的发表不仅将有助于将来对 α-Syn的研究，而且可能会扩展到其他蛋白质，这些蛋白质是各种神经退行性疾病的基础。

BACKGROUND & AIMS: :The critical observation in the pathology of Parkinson's disease (PD) is that neurodegeneration is largely restricted to dopaminergic neurons that develop cytoplasmic inclusions called Lewy bodies. These aggregations contain the protein alpha-synuclein. Furthermore, it is becoming apparent that alpha-synuclein expression levels are a major factor in PD pathogenesis. Patients with additional copies of the alpha-synuclein gene develop PD with a severity proportional to levels of alpha-synuclein overexpression. Similarly, overexpression of alpha-synuclein in in vitro and in vivo models has been shown to be toxic. However, little is known about the effects of reducing alpha-synuclein expression in human neurons. To investigate this, we have developed a system in which levels of alpha-synuclein can be acutely suppressed by using RNA interference (RNAi) in a physiologically relevant human dopaminergic cellular model. By using small interfering RNA (siRNA) molecules targeted to endogenous alpha-synuclein, we achieved 80% protein knockdown. We show that alpha-synuclein knockdown has no effect on cellular survival either under normal growth conditions over 5 days or in the presence of the mitochondrial inhibitor rotenone. Knockdown does, however, confer resistance to the dopamine transporter (DAT)-dependent neurotoxin N-methyl-4-phenylpyridinium (MPP(+)). We then demonstrate for the first time that alpha-synuclein suppression decreases dopamine transport in human cells, reducing the maximal uptake velocity (V(max)) of dopamine and the surface density of its transporter by up to 50%. These results show that RNAi-mediated alpha-synuclein knockdown alters cellular dopamine homeostasis in human cells and may suggest a mechanism for the increased survival in the presence of MPP(+), a toxin used extensively to model Parkinson's disease.

背景与目标： : 帕金森氏病 (PD) 病理学中的关键观察结果是，神经退行性变主要限于多巴胺能神经元，这些神经元形成称为路易体的细胞质内含物。这些聚集物包含蛋白质 α-突触核蛋白。此外，越来越明显的是，α-突触核蛋白表达水平是PD发病机理的主要因素。具有额外的 α-突触核蛋白基因拷贝的患者发展为PD，其严重程度与 α-突触核蛋白过表达水平成正比。同样，在体外和体内模型中 α-突触核蛋白的过表达已被证明是有毒的。然而，人们对减少人类神经元中 α-突触核蛋白表达的作用知之甚少。为了研究这一点，我们开发了一种系统，在该系统中，可以通过在生理相关的人类多巴胺能细胞模型中使用RNA干扰 (RNAi) 来严重抑制 α-突触核蛋白的水平。通过使用靶向内源性 α-突触核蛋白的小干扰RNA (siRNA) 分子，我们实现了80% 蛋白敲除。我们显示，在正常生长条件下5天或存在线粒体抑制剂鱼藤酮的情况下，α-突触核蛋白敲低对细胞存活没有影响。但是，敲低确实赋予了对多巴胺转运蛋白 (DAT) 依赖性神经毒素N-methyl-4-phenylpyridinium (MPP ()) 的抵抗力。然后，我们首次证明 α-突触核蛋白抑制降低了人细胞中的多巴胺转运，使多巴胺的最大摄取速度 (V(max)) 及其转运蛋白的表面密度降低了多达50%。这些结果表明，RNAi介导的 α-突触核蛋白敲低改变了人类细胞中细胞多巴胺的稳态，并可能暗示了在MPP () (一种广泛用于模拟帕金森氏病的毒素) 存在下增加存活率的机制。