JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Phosphorylation modulates clearance of alpha-synuclein inclusions in a yeast model of Parkinson's disease.
PLoS Genet.
PUBLISHED: 05-01-2014
Show Abstract
Hide Abstract
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.
Related JoVE Video
Yeast DJ-1 superfamily members are required for diauxic-shift reprogramming and cell survival in stationary phase.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 04-02-2014
Show Abstract
Hide Abstract
The yeast Hsp31 minifamily proteins (Hsp31, Hsp32, Hsp33, Hsp34) belong to the highly conserved DJ-1 superfamily. The human DJ-1 protein is associated with cancer and neurodegenerative disorders, such as Parkinson disease. However, the precise function of human and yeast DJ-1 proteins is unclear. Here we show that the yeast DJ-1 homologs have a role in diauxic-shift (DS), characterized by metabolic reprogramming because of glucose limitation. We find that the Hsp31 genes are strongly induced in DS and in stationary phase (SP), and that deletion of these genes reduces chronological lifespan, impairs transcriptional reprogramming at DS, and impairs the acquisition of several typical characteristics of SP, including autophagy induction. In addition, under carbon starvation, the HSP31 family gene-deletion strains display impaired autophagy, disrupted target of rapamycin complex 1 (TORC1) localization to P-bodies, and caused abnormal TORC1-mediated Atg13 phosphorylation. Repression of TORC1 by rapamycin in the gene-deletion strains completely reversed their sensitivity to heat shock. Taken together, our data indicate that Hsp31 minifamily is required for DS reprogramming and cell survival in SP, and plays a role upstream of TORC1. The enhanced understanding of the cellular function of these genes sheds light into the biological role of other members of the superfamily, including DJ-1, which is an attractive target for therapeutic intervention in cancer and in Parkinson disease.
Related JoVE Video
Challenges and promises in the development of neurotrophic factor-based therapies for Parkinson's disease.
Drugs Aging
PUBLISHED: 03-11-2014
Show Abstract
Hide Abstract
Parkinson's disease (PD) is a chronic movement disorder typically coupled to progressive degeneration of dopaminergic neurons in the substantia nigra (SN). The treatments currently available are satisfactory for symptomatic management, but the efficacy tends to decrease as neuronal loss progresses. Neurotrophic factors (NTFs) are endogenous proteins known to promote neuronal survival, even in degenerating states. Therefore, the use of these factors is regarded as a possible therapeutic approach, which would aim to prevent PD or to even restore homeostasis in neurodegenerative disorders. Intriguingly, although favorable results in in vitro and in vivo models of the disease were attained, clinical trials using these molecules have failed to demonstrate a clear therapeutic benefit. Therefore, the development of animal models that more closely reproduce the mechanisms known to underlie PD-related neurodegeneration would be a major step towards improving the capacity to predict the clinical usefulness of a given NTF-based approach in the experimental setting. Moreover, some adjustments to the design of clinical trials ought to be considered, which include recruiting patients in the initial stages of the disease, improving the efficacy of the delivery methods, and combining synergetic NTFs or adding NTF-boosting drugs to the already available pharmacological approaches. Despite the drawbacks on the road to the use of NTFs as pharmacological tools for PD, very relevant achievements have been reached. In this article, we review the current status of the potential relevance of NTFs for treating PD, taking into consideration experimental evidence, human observational studies, and data from clinical trials.
Related JoVE Video
PLK2 modulates ?-synuclein aggregation in yeast and mammalian cells.
Mol. Neurobiol.
PUBLISHED: 03-15-2013
Show Abstract
Hide Abstract
Phosphorylation of ?-synuclein (aSyn) on serine 129 is one of the major post-translation modifications found in Lewy bodies, the typical pathological hallmark of Parkinsons 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.
Related JoVE Video
The NAD-dependent deacetylase sirtuin 2 is a suppressor of microglial activation and brain inflammation.
EMBO J.
PUBLISHED: 01-22-2013
Show Abstract
Hide Abstract
Deleterious sustained inflammation mediated by activated microglia is common to most of neurologic disorders. Here, we identified sirtuin 2 (SIRT2), an abundant deacetylase in the brain, as a major inhibitor of microglia-mediated inflammation and neurotoxicity. SIRT2-deficient mice (SIRT2(-/-)) showed morphological changes in microglia and an increase in pro-inflammatory cytokines upon intracortical injection of lipopolysaccharide (LPS). This response was associated with increased nitrotyrosination and neuronal cell death. Interestingly, manipulation of SIRT2 levels in microglia determined the response to Toll-like receptor (TLR) activation. SIRT2 overexpression inhibited microglia activation in a process dependent on serine 331 (S331) phosphorylation. Conversely, reduction of SIRT2 in microglia dramatically increased the expression of inflammatory markers, the production of free radicals, and neurotoxicity. Consistent with increased NF-?B-dependent transcription of inflammatory genes, NF-?B was found hyperacetylated in the absence of SIRT2, and became hypoacetylated in the presence of S331A mutant SIRT2. This finding indicates that SIRT2 functions as a gatekeeper, preventing excessive microglial activation through NF-?B deacetylation. Our data uncover a novel role for SIRT2 opening new perspectives for therapeutic intervention in neuroinflammatory disorders.
Related JoVE Video
Assessing the subcellular dynamics of alpha-synuclein using photoactivation microscopy.
Mol. Neurobiol.
PUBLISHED: 01-08-2013
Show Abstract
Hide Abstract
Alpha-synuclein (aSyn) is implicated in Parkinsons disease and several other neurodegenerative disorders. To date, the function and intracellular dynamics of aSyn are still unclear. Here, we tracked the dynamics of aSyn using photoactivatable green fluorescent protein as a reporter. We found that the availability of the aSyn N terminus modulates its shuttling into the nucleus. Interestingly, familial aSyn mutations altered the dynamics at which the protein distributes throughout the cell. Both the A30P and A53T aSyn mutations increase the speed at which the protein moves between the nucleus and cytoplasm, respectively. We also found that specific kinases potentiate the shuttling of aSyn between nucleus and cytoplasm. A mutant aSyn form that blocks S129 phosphorylation, S129A, results in the formation of cytoplasmic inclusions, suggesting phosphorylation modulates aggregation in addition to modulating aSyn intracellular dynamics. Finally, we found that the molecular chaperone HSP70 accelerates the entry of aSyn into the nuclear compartment.
Related JoVE Video
?-Synuclein modifies huntingtin aggregation in living cells.
FEBS Lett.
PUBLISHED: 10-26-2011
Show Abstract
Hide Abstract
Several neurodegenerative disorders are characterized by the accumulation of proteinaceous inclusions in the central nervous system. These inclusions are frequently composed of a mixture of aggregation-prone proteins. Here, we used a bimolecular fluorescence complementation assay to study the initial steps of the co-aggregation of huntingtin (Htt) and ?-synuclein (?-syn), two aggregation-prone proteins involved in Huntingtons disease (HD) and Parkinsons disease (PD), respectively. We found that Htt (exon 1) oligomerized with ?-syn and sequestered it in the cytosol. In turn, ?-syn increased the number of cells displaying aggregates, decreased the number of aggregates per cell and increased the average size of the aggregates. Our results support the idea that co-aggregation of aggregation-prone proteins can contribute to the histopathology of neurodegenerative disorders.
Related JoVE Video
Tau enhances ?-synuclein aggregation and toxicity in cellular models of synucleinopathy.
PLoS ONE
PUBLISHED: 05-02-2011
Show Abstract
Hide Abstract
The simultaneous accumulation of different misfolded proteins in the central nervous system is a common feature in many neurodegenerative diseases. In most cases, co-occurrence of abnormal deposited proteins is observed in different brain regions and cell populations, but, in some instances, the proteins can be found in the same cellular aggregates. Co-occurrence of tau and ?-synuclein (?-syn) aggregates has been described in neurodegenerative disorders with primary deposition of ?-syn, such as Parkinsons disease and dementia with Lewy bodies. Although it is known that tau and ?-syn have pathological synergistic effects on their mutual fibrillization, the underlying biological effects remain unclear.
Related JoVE Video
Impaired proteostasis contributes to renal tubular dysgenesis.
PLoS ONE
PUBLISHED: 03-23-2011
Show Abstract
Hide Abstract
Protein conformational disorders are associated with the appearance, persistence, accumulation, and misprocessing of aberrant proteins in the cell. The etiology of renal tubular dysgenesis (RTD) is linked to mutations in the angiotensin-converting enzyme (ACE). Here, we report the identification of a novel ACE mutation (Q1069R) in an RTD patient. ACE Q1069R is found sequestered in the endoplasmic reticulum and is also subject to increased proteasomal degradation, preventing its transport to the cell surface and extracellular fluids. Modulation of cellular proteostasis by temperature shift causes an extension in the processing time and trafficking of ACE Q1069R resulting in partial rescue of the protein processing defect and an increase in plasma membrane levels. In addition, we found that temperature shifting causes the ACE Q1069R protein to be secreted in an active state, suggesting that the mutation does not affect the enzymes catalytic properties.
Related JoVE Video
Visualization of cell-to-cell transmission of mutant huntingtin oligomers.
PLoS Curr
PUBLISHED: 02-04-2011
Show Abstract
Hide Abstract
We developed a new cell model for the visualization of toxic huntingtin oligomers in living cells. Huntingtin exon 1 (25Q or 103Q) was fused to non-fluorescent halves of the Venus protein. When huntingtin dimerizes inside the cells, Venus becomes functionally reconstituted and emits fluorescence. Oligomerization, aggregation and toxicity of mutant huntingtin were assessed by several procedures. We also present evidence that the transmission of huntingtin between cells can be determined in a quantitative manner with our model. Thus, this model can be a powerful screening tool for the identification of modifiers of oligomerization and cell-to-cell traffic of mutant huntingtin.
Related JoVE Video
Simple is good: yeast models of neurodegeneration.
FEMS Yeast Res.
PUBLISHED: 06-29-2010
Show Abstract
Hide Abstract
The budding yeast, Saccharomyces cerevisiae, is the best-studied eukaryotic cell, at both genetic and physiological levels. As a eukaryote, yeast shares highly conserved molecular and cellular mechanisms with human cells. Thus, this simple fungus is an invaluable model to study the fundamental molecular mechanisms involved in several human diseases. In the particular case of neurodegenerative disorders, yeast models have been able to recapitulate several important features of complex and devastating disorders, such as Huntingtons and Parkinsons diseases. Once validated, these models have also been used to accelerate the identification of both novel therapeutic targets and compounds with therapeutic potential. Here, we review the recent contributions of this simple, but powerful model organism toward our understanding of neurodegeneration.
Related JoVE Video
Synphilin-1 enhances ?-synuclein aggregation in yeast and contributes to cellular stress and cell death in a Sir2-dependent manner.
PLoS ONE
PUBLISHED: 03-10-2010
Show Abstract
Hide Abstract
Parkinsons disease is characterized by the presence of cytoplasmic inclusions, known as Lewy bodies, containing both aggregated ?-synuclein and its interaction partner, synphilin-1. While synphilin-1 is known to accelerate inclusion formation by ?-synuclein in mammalian cells, its effect on cytotoxicity remains elusive.
Related JoVE Video
The sour side of neurodegenerative disorders: the effects of protein glycation.
J. Pathol.
PUBLISHED: 02-27-2010
Show Abstract
Hide Abstract
Neurodegenerative diseases are associated with the misfolding and deposition of specific proteins, either intra- or extracellularly in the nervous system. Although familial mutations play an important role in protein misfolding and aggregation, the majority of cases of neurodegenerative diseases are sporadic, suggesting that other factors must contribute to the onset and progression of these disorders. Post-translational modifications are known to influence protein structure and function. Some of these modifications might affect proteins in detrimental ways and lead to their misfolding and accumulation. Reducing sugars play important roles in modifying proteins, forming advanced glycation end-products (AGEs) in a non-enzymatic process named glycation. Several proteins linked to neurodegenerative diseases, such as amyloid beta, tau, prions and transthyretin, were found to be glycated in patients, and this is thought to be associated with increased protein stability through the formation of crosslinks that stabilize protein aggregates. Moreover, glycation may be responsible, via the receptor for AGE (RAGE), for an increase in oxidative stress and inflammation through the formation of reactive oxygen species and the induction of NF-kappaB. Therefore, it is essential to unravel the molecular mechanisms underlying protein glycation to understand their role in neurodegeneration. Here, we reviewed the role of protein glycation in the major neurodegenerative disorders and highlight the potential value of protein glycation as a biomarker or target for therapeutic intervention.
Related JoVE Video
Sirtuins: common targets in aging and in neurodegeneration.
Curr Drug Targets
PUBLISHED: 01-18-2010
Show Abstract
Hide Abstract
Aging has been a subject of interest since primordial times. More recently, it became clear that aging is the major known risk factor for several neurodegenerative disorders, such as Alzheimers disease, Parkinsons disease and Huntingtons disease. A major focus in the field of aging is to examine whether the genetic regulators of lifespan also regulate the trigger and/or progression of age-related disorders. Sirtuins, which belong to the Sir2 family of NAD(+)-dependent deacetylases, are known to regulate longevity in yeast, worms, and flies. In mammals, there are seven homologs of the yeast Sir2, Sirt1-7. Therefore, the challenge now is to unravel howthe seven mammalian Sir2 proteins communicate to regulate the cross talk between aging and the onset and progression of age-related disorders. Here, we review how sirtuins contribute for aging and, in particular, for neurodegeneration and how they are becoming attractive targets for therapeutic intervention.
Related JoVE Video
Neurotrophic factors as a protective strategy in Parkinsons disease.
CNS Neurol Disord Drug Targets
PUBLISHED: 01-04-2010
Show Abstract
Hide Abstract
Neurodegenerative disorders are devastating human diseases that include Parkinsons, Huntingtons, Alzheimers, amyotrophic lateral sclerosis, and the frontal temporal dementias. Although the clinical manifestations of these disorders have been known for quite some time, our understanding of the molecular underpinnings is only starting to emerge. Protein misfolding and aggregation is a common hallmark among these diseases, and produce a number of cellular and functional alterations. The loss of dopaminergic neurons in the substantia nigra justified the use of dopaminergic therapies in patients. However, these strategies do not appear to confer disease-modifying effects, and do not prevent progression. The idea that neurotrophic factors might promote cell survival is an attractive one. Existing evidence from clinical trials is currently inconclusive, but some patients display clear clinical benefits. Thus, the current challenge is to develop novel strategies that make the use of neurotrophic factors more consistent.
Related JoVE Video
Compounds from an unbiased chemical screen reverse both ER-to-Golgi trafficking defects and mitochondrial dysfunction in Parkinsons disease models.
Dis Model Mech
PUBLISHED: 12-28-2009
Show Abstract
Hide Abstract
alpha-Synuclein (alpha-syn) is a small lipid-binding protein involved in vesicle trafficking whose function is poorly characterized. It is of great interest to human biology and medicine because alpha-syn dysfunction is associated with several neurodegenerative disorders, including Parkinsons disease (PD). We previously created a yeast model of alpha-syn pathobiology, which established vesicle trafficking as a process that is particularly sensitive to alpha-syn expression. We also uncovered a core group of proteins with diverse activities related to alpha-syn toxicity that is conserved from yeast to mammalian neurons. Here, we report that a yeast strain expressing a somewhat higher level of alpha-syn also exhibits strong defects in mitochondrial function. Unlike our previous strain, genetic suppression of endoplasmic reticulum (ER)-to-Golgi trafficking alone does not suppress alpha-syn toxicity in this strain. In an effort to identify individual compounds that could simultaneously rescue these apparently disparate pathological effects of alpha-syn, we screened a library of 115,000 compounds. We identified a class of small molecules that reduced alpha-syn toxicity at micromolar concentrations in this higher toxicity strain. These compounds reduced the formation of alpha-syn foci, re-established ER-to-Golgi trafficking and ameliorated alpha-syn-mediated damage to mitochondria. They also corrected the toxicity of alpha-syn in nematode neurons and in primary rat neuronal midbrain cultures. Remarkably, the compounds also protected neurons against rotenone-induced toxicity, which has been used to model the mitochondrial defects associated with PD in humans. That single compounds are capable of rescuing the diverse toxicities of alpha-syn in yeast and neurons suggests that they are acting on deeply rooted biological processes that connect these toxicities and have been conserved for a billion years of eukaryotic evolution. Thus, it seems possible to develop novel therapeutic strategies to simultaneously target the multiple pathological features of PD.
Related JoVE Video
Current and future therapeutic strategies for Parkinsons disease.
Curr. Pharm. Des.
PUBLISHED: 06-25-2009
Show Abstract
Hide Abstract
The heterogeneity of symptoms and disease progression observed in synucleinopathies, of which Parkinsons disease (PD) is the most common representative, poses large problems for its treatment and for the discovery of novel therapeutics. The molecular basis for pathology is currently unclear, both in familial and in sporadic cases. While the therapeutic effects of L-DOPA and dopamine receptor agonists are still the gold standards for symptomatic treatment in PD, the development of neuroprotective and/or neurorestorative treatments for these disorders faces significant challenges due to the poor knowledge of the putative targets involved. Recent experimental evidence strongly suggests a central role for neurotoxic alpha-synuclein oligomeric species in neurodegeneration. The events leading to protein oligomerization, as well as the oligomeric species themselves, are likely amenable to modulation by small molecules, which are beginning to emerge in high throughput compound screens in a variety of model organisms. The therapeutic potential of small molecule modulators of oligomer formation demands further exploration and validation in cellular and animal disease models in order to accelerate human drug development.
Related JoVE Video
Live-cell imaging of p53 interactions using a novel Venus-based bimolecular fluorescence complementation system.
Biochem. Pharmacol.
Show Abstract
Hide Abstract
p53 plays an important role in regulating a wide variety of cellular processes, such as cell cycle arrest and/or apoptosis. Dysfunction of p53 is frequently associated with several pathologies, such as cancer and neurodegenerative diseases. In recent years substantial progress has been made in developing novel p53-activating molecules. Importantly, modulation of p53 interaction with its main inhibitor, Mdm2, has been highlighted as a promising therapeutic target. In this regard, bimolecular fluorescence complementation (BiFC) analysis, by providing direct visualization of protein interactions in living cells, offers a straightforward method to identify potential modulators of protein interactions. In this study, we developed a simple and robust Venus-based BiFC system to screen for modulators of p53-p53 and p53-Mdm2 interactions in live mammalian cells. We used nutlin-3, a well-known disruptor of p53-Mdm2 interaction, to validate the specificity of the assay. The reduction of BiFC signal mediated by nutlin-3 was correlated with an increase in Puma transactivation, PARP cleavage, and cell death. Finally, this novel BiFC approach was exploited to identify potential modulators of p53-Mdm2 complex formation among a commercially available chemical library of 33 protein phosphatase inhibitors. Our results constitute "proof-of-concept" that this model has strong potential as an alternative to traditional target-based drug discovery strategies. Identification of new modulators of p53-p53 and p53-Mdm2 interactions will be useful to achieve synergistic drug efficacy with currently used anti-tumor therapies.
Related JoVE Video
LRRK2 interactions with ?-synuclein in Parkinsons disease brains and in cell models.
J. Mol. Med.
Show Abstract
Hide Abstract
Mutations in the genes encoding leucine-rich repeat kinase 2 (LRRK2) and ?-synuclein are associated with both autosomal dominant and idiopathic forms of Parkinsons disease (PD). ?-Synuclein is the main protein in Lewy bodies, hallmark inclusions present in both sporadic and familial PD. We show that in PD brain tissue, the levels of LRRK2 are positively related to the increase in ?-synuclein phosphorylation and aggregation in affected brain regions (amygdala and anterior cingulate cortex), but not in the unaffected visual cortex. In disease-affected regions, we show co-localization of these two proteins in neurons and Lewy body inclusions. Further, in vitro experiments show a molecular interaction between ?-synuclein and LRRK2 under endogenous and over-expression conditions. In a cell culture model of ?-synuclein inclusion formation, LRRK2 co-localizes with the ?-synuclein inclusions, and knocking down LRRK2 increases the number of smaller inclusions. In addition to providing strong evidence for an interaction between LRRK2 and ?-synuclein, our results shed light on the complex relationship between these two proteins in the brains of patients with PD and the underlying molecular mechanisms of the disease.
Related JoVE Video
The zebrafish homologue of Parkinsons disease ATP13A2 is essential for embryonic survival.
Brain Res. Bull.
Show Abstract
Hide Abstract
ATP13A2 is a lysosome-specific transmembrane ATPase protein of unknown function. This protein was initially linked to Kufor-Rakeb syndrome where it is absent or mutated. More recently, point mutations in ATP13A2 were linked to familial cases of Parkinsons disease. Zebrafish is commonly used as a vertebrate model for the study of different neurodegenerative diseases and has homologues of several Parkinsons disease associated proteins. Here, we describe for the first time the zebrafish homologue of human ATP13A2, demonstrating the homology between the protein sequences, which supports a conserved biological role. Furthermore, the spatial pattern of protein expression was studied and the lethality of the knockdown of ATP13A2 suggests it plays a crucial role during embryonic development. Our findings bring new insight into the biology of ATP13A2 and open novel opportunities for its study using zebrafish as a model organism.
Related JoVE Video
Extracellular alpha-synuclein oligomers modulate synaptic transmission and impair LTP via NMDA-receptor activation.
J. Neurosci.
Show Abstract
Hide Abstract
Parkinsons disease (PD) is the most common representative of a group of disorders known as synucleinopathies, in which misfolding and aggregation of ?-synuclein (a-syn) in various brain regions is the major pathological hallmark. Indeed, the motor symptoms in PD are caused by a heterogeneous degeneration of brain neurons not only in substantia nigra pars compacta but also in other extrastriatal areas of the brain. In addition to the well known motor dysfunction in PD patients, cognitive deficits and memory impairment are also an important part of the disorder, probably due to disruption of synaptic transmission and plasticity in extrastriatal areas, including the hippocampus. Here, we investigated the impact of a-syn aggregation on AMPA and NMDA receptor-mediated rat hippocampal (CA3-CA1) synaptic transmission and long-term potentiation (LTP), the neurophysiological basis for learning and memory. Our data show that prolonged exposure to a-syn oligomers, but not monomers or fibrils, increases basal synaptic transmission through NMDA receptor activation, triggering enhanced contribution of calcium-permeable AMPA receptors. Slices treated with a-syn oligomers were unable to respond with further potentiation to theta-burst stimulation, leading to impaired LTP. Prior delivery of a low-frequency train reinstated the ability to express LTP, implying that exposure to a-syn oligomers drives the increase of glutamatergic synaptic transmission, preventing further potentiation by physiological stimuli. Our novel findings provide mechanistic insight on how a-syn oligomers may trigger neuronal dysfunction and toxicity in PD and other synucleinopathies.
Related JoVE Video
SIRT2 as a Therapeutic Target for Age-Related Disorders.
Front Pharmacol
Show Abstract
Hide Abstract
Sirtuin proteins are conserved regulators of aging that have recently emerged as important modifiers of several diseases which commonly occur later in life such as cancer, diabetes, cardiovascular, and neurodegenerative diseases. In mammals, there are seven sirtuins (SIRT1-7), which display diversity in subcellular localization and function. SIRT1 has received much of attention due to its possible impact on longevity, while important biological and therapeutic roles of other sirtuins have been underestimated and just recently recognized. Here we focus on SIRT2, a member of the sirtuin family, and discuss its role in cellular and tissue-specific functions. This review summarizes the main scientific advances on SIRT2 protein biology and explores its potential as a therapeutic target for treatment of age-related disorders.
Related JoVE Video
Imaging protein oligomerization in neurodegeneration using bimolecular fluorescence complementation.
Meth. Enzymol.
Show Abstract
Hide Abstract
Neurodegenerative disorders such as Alzheimers, Parkinsons, Huntingtons, or Prion diseases belong to a superfamily of pathologies known as protein misfolding disorders. The hallmark of these pathologies is the aberrant accumulation of specific proteins in beta sheet-rich amyloid aggregates either inside or outside cells. Current evidence suggests that oligomeric species, rather than mature protein aggregates, are the most toxic forms of the pathogenic proteins. This is due, at least in part, to their greater solubility and ability to diffuse between intracellular and extracellular compartments. Understanding how oligomerization occurs is essential for the development of new treatments for this group of diseases. Bimolecular fluorescence complementation assays (BiFC) have proved to be excellent systems to study aberrant protein-protein interactions, including those involved in neurodegenerative diseases. Here, we provide a detailed description of the rationale to develop and validate BiFC assays for the visualization of oligomeric species in living cells in the context of neurodegeneration. These systems could constitute powerful tools for the identification of genetic and pharmacological modifiers of protein misfolding and aggregation.
Related JoVE Video

What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.