排序方式: 共有78条查询结果,搜索用时 31 毫秒
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Sandra Tenreiro Madalena M. Reim?o-Pinto Pedro Antas José Rino Donata Wawrzycka Diana Macedo Rita Rosado-Ramos Triana Amen Meytal Waiss Filipa Magalh?es Andreia Gomes Cláudia N. Santos Daniel Kaganovich Tiago Fleming Outeiro 《PLoS genetics》2014,10(5)
Alpha-synuclein (aSyn) is the main component of proteinaceous inclusions known as Lewy bodies (LBs), the typical pathological hallmark of Parkinson''s disease (PD) and other synucleinopathies. Although aSyn is phosphorylated at low levels under physiological conditions, it is estimated that ∼90% of aSyn in LBs is phosphorylated at S129 (pS129). Nevertheless, the significance of pS129 in the biology of aSyn and in PD pathogenesis is still controversial. Here, we harnessed the power of budding yeast in order to assess the implications of phosphorylation on aSyn cytotoxicity, aggregation and sub-cellular distribution. We found that aSyn is phosphorylated on S129 by endogenous kinases. Interestingly, phosphorylation reduced aSyn toxicity and the percentage of cells with cytosolic inclusions, in comparison to cells expressing mutant forms of aSyn (S129A or S129G) that mimic the unphosphorylated form of aSyn. Using high-resolution 4D imaging and fluorescence recovery after photobleaching (FRAP) in live cells, we compared the dynamics of WT and S129A mutant aSyn. While WT aSyn inclusions were very homogeneous, inclusions formed by S129A aSyn were larger and showed FRAP heterogeneity. Upon blockade of aSyn expression, cells were able to clear the inclusions formed by WT aSyn. However, this process was much slower for the inclusions formed by S129A aSyn. Interestingly, whereas the accumulation of WT aSyn led to a marked induction of autophagy, cells expressing the S129A mutant failed to activate this protein quality control pathway. The finding that the phosphorylation state of aSyn on S129 can alter the ability of cells to clear aSyn inclusions provides important insight into the role that this posttranslational modification may have in the pathogenesis of PD and other synucleinopathies, opening novel avenues for investigating the molecular basis of these disorders and for the development of therapeutic strategies. 相似文献
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Noncoding RNAs have recently been identified as essential components of the nuclear suborganelles called paraspeckles. This finding will facilitate our understanding of the molecular dynamics and physiological role of these enigmatic macromolecular structures. 相似文献
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Manouchehr Nakhjavani Afsaneh Morteza Leila Khajeali Alireza Esteghamati Omid Khalilzadeh Firouzeh Asgarani Tiago F. Outeiro 《Cell stress & chaperones》2010,15(6):959-964
The evolutionary conserved family of heat shock proteins (HSP) is responsible for protecting cells against different types
of stress, including oxidative stress. Although the levels of HSPs can be readily measured in blood serum, the levels of HSP70
in patients with different durations of diabetes have not been studied before. We quantified serum HSP70 levels in a healthy
control group (n = 36) and two groups of type 2 diabetic patients, defined as newly diagnosed diabetes (n = 36) and patients with diabetes duration of more than 5 years (n = 37). The clinical characteristics and biochemical parameters were evaluated in the studied population. We found that serum
HSP70 levels were significantly higher in patients with diabetes when compared with controls (p < 0.001) and it was higher in patients with disease for more than 5 years than in newly diagnosed patients (p < 0.001). Serum HSP70 was inversely correlated with fasting blood sugar in patients with diabetes for more than 5 years (r = −0.500, p = 0.002), positively correlated with the history of hypertension in newly diagnosed patients (p < 0.001), and positively correlated with age in patients with diabetes (r = 0.531, p = 0.001). Serum level of HSP70 is significantly higher in patients with diabetes and correlates with the duration of disease.
Higher HSP70 in prolonged diabetes versus newly diagnosed diabetes may be an indicator of metabolic derangement in the course
of diabetes. 相似文献
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Several neurodegenerative diseases, such as Parkinson's disease (PD), Alzheimer's disease (AD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS), or prion diseases, are known for their intimate association with protein misfolding and aggregation. These disorders are characterized by the loss of specific neuronal populations in the brain and are highly associated with aging, suggesting a decline in proteostasis capacity may contribute to pathogenesis. Nevertheless, the precise molecular mechanisms that lead to the selective demise of neurons remain poorly understood. As a consequence, appropriate therapeutic approaches and effective treatments are largely lacking. The development of cellular and animal models that faithfully reproduce central aspects of neurodegeneration has been crucial for advancing our understanding of these diseases. Approaches involving the sequential use of different model systems, starting with simpler cellular models and ending with validation in more complex animal models, resulted in the discovery of promising therapeutic targets and small molecules with therapeutic potential. Within this framework, the simple and well‐characterized eukaryote Saccharomyces cerevisiae, also known as budding yeast, is being increasingly used to study the molecular basis of several neurodegenerative disorders. Yeast provides an unprecedented toolbox for the dissection of complex biological processes and pathways. Here, we summarize how yeast models are adding to our current understanding of several neurodegenerative disorders. 相似文献
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Elisa Basso Pedro Antas Zrinka Marijanovic Susana Gonçalves Sandra Tenreiro Tiago Fleming Outeiro 《Molecular neurobiology》2013,48(3):854-862
Phosphorylation of α-synuclein (aSyn) on serine 129 is one of the major post-translation modifications found in Lewy bodies, the typical pathological hallmark of Parkinson’s disease. Here, we found that both PLK2 and PLK3 phosphorylate aSyn on serine 129 in yeast. However, only PLK2 increased aSyn cytotoxicity and the percentage of cells presenting cytoplasmic foci. Consistently, in mammalian cells, PLK2 induced aSyn phosphorylation on serine 129 and induced an increase in the size of the inclusions. Our study supports a role for PLK2 in the generation of aSyn inclusions by a mechanism that does not depend directly on serine 129 phosphorylation. 相似文献
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Jorge CD Ventura R Maycock C Outeiro TF Santos H Costa J 《Neurochemical research》2011,36(6):1005-1011
Protein misfolding and deposition in the brain are implicated in the etiology of numerous neurodegenerative disorders. Here,
organic solutes characteristic of microorganisms adapted to hot environments, were tested on experimental cell models of Huntington’s
and Parkinson’s diseases. Diglycerol phosphate, di-myo-inositol phosphate, mannosylglycerate, and mannosylglyceramide were not toxic to the cells, at 10 mM concentration, but caused
a decrease in cell density, which suggested an effect on proliferation. In contrast, mannosyl-lactate, an artificial analogue
of mannosylglycerate, had a negative impact on cell viability. Concerning protein aggregation, inclusions of mutant huntingtin
were reduced in the presence of diglycerol phosphate and di-myo-inositol phosphate, increased with mannosylglycerate, while mannosyl-lactate and mannosylglyceramide had no significant effect.
α-Synuclein aggregation was not affected by the solutes tested, except for di-myo-inositol phosphate that led to a slight increased percentage of cells displaying visible aggregates. These solutes might
be useful in the development of therapies for protein misfolding diseases. 相似文献
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Tiago F. Outeiro Jochen Klucken Kathryn Bercury Julie Tetzlaff Preeti Putcha Luis M. A. Oliveira Alexandre Quintas Pamela J. McLean Bradley T. Hyman 《PloS one》2009,4(9)
Background
Oligomerization and aggregation of α-synuclein molecules play a major role in neuronal dysfunction and loss in Parkinson''s disease [1]. However, α-synuclein oligomerization and aggregation have mostly been detected indirectly in cells using detergent extraction methods [2], [3], [4]. A number of in vitro studies showed that dopamine can modulate the aggregation of α-synuclein by inhibiting the formation of or by disaggregating amyloid fibrils [5], [6], [7].Methodology/Principal Findings
Here, we show that α-synuclein adopts a variety of conformations in primary neuronal cultures using fluorescence lifetime imaging microscopy (FLIM). Importantly, we found that dopamine, but not dopamine agonists, induced conformational changes in α-synuclein which could be prevented by blocking dopamine transport into the cell. Dopamine also induced conformational changes in α-synuclein expressed in neuronal cell lines, and these changes were also associated with alterations in oligomeric/aggregated species.Conclusion/Significance
Our results show, for the first time, a direct effect of dopamine on the conformation of α-synuclein in neurons, which may help explain the increased vulnerability of dopaminergic neurons in Parkinson''s disease. 相似文献40.
Conservation status of freshwater mussels in Europe: state of the art and future challenges 下载免费PDF全文
Manuel Lopes‐Lima David C. Aldridge Rafael Araujo Jakob Bergengren Yulia Bespalaya Erika Bódis Lyubov Burlakova Dirk Van Damme Karel Douda Elsa Froufe Dilian Georgiev Clemens Gumpinger Alexander Karatayev Ümit Kebapçi Ian Killeen Jasna Lajtner Bjørn M. Larsen Rosaria Lauceri Anastasios Legakis Sabela Lois Stefan Lundberg Evelyn Moorkens Gregory Motte Karl‐Otto Nagel Paz Ondina Adolfo Outeiro Momir Paunovic Vincent Prié Ted von Proschwitz Nicoletta Riccardi Mudīte Rudzīte Māris Rudzītis Christian Scheder Mary Seddon Hülya Şereflişan Vladica Simić Svetlana Sokolova Katharina Stoeckl Jouni Taskinen Amílcar Teixeira Frankie Thielen Teodora Trichkova Simone Varandas Heinrich Vicentini Katarzyna Zajac Tadeusz Zajac Stamatis Zogaris 《Biological reviews of the Cambridge Philosophical Society》2017,92(1):572-607
Freshwater mussels of the Order Unionida provide important ecosystem functions and services, yet many of their populations are in decline. We comprehensively review the status of the 16 currently recognized species in Europe, collating for the first time their life‐history traits, distribution, conservation status, habitat preferences, and main threats in order to suggest future management actions. In northern, central, and eastern Europe, a relatively homogeneous species composition is found in most basins. In southern Europe, despite the lower species richness, spatially restricted species make these basins a high conservation priority. Information on freshwater mussels in Europe is unevenly distributed with considerable differences in data quality and quantity among countries and species. To make conservation more effective in the future, we suggest greater international cooperation using standardized protocols and methods to monitor and manage European freshwater mussel diversity. Such an approach will not only help conserve this vulnerable group but also, through the protection of these important organisms, will offer wider benefits to freshwater ecosystems. 相似文献