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Find video protocols related to scientific articles indexed in Pubmed.
Abnormal structure-specific peptide transmission and processing in a primate model of Parkinsons disease and l-DOPA-induced dyskinesia.
Neurobiol. Dis.
PUBLISHED: 09-14-2013
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A role for enhanced peptidergic transmission, either opioidergic or not, has been proposed for the generation of l-3,4-dihydroxyphenylalanine (l-DOPA)-induced dyskinesia (LID) on the basis of in situ hybridization studies showing that striatal peptidergic precursor expression consistently correlates with LID severity. Few studies, however, have focused on the actual peptides derived from these precursors. We used mass-spectrometry to study peptide profiles in the putamen and globus pallidus (internalis and externalis) collected from 1-methyl-4-phenyl-1,2,4,6-tetrahydropyridine treated macaque monkeys, acutely or chronically treated with l-DOPA. We identified that parkinsonian and dyskinetic states are associated with an abnormal production of proenkephalin-, prodynorphin- and protachykinin-1-derived peptides in both segments of the globus pallidus. Moreover, we report that peptidergic processing is dopamine-state dependent and highly structure-specific, possibly explaining the failure of previous clinical trials attempting to rectify abnormal peptidergic transmission.
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Asymmetry of the Endogenous Opioid System in the Human Anterior Cingulate: a Putative Molecular Basis for Lateralization of Emotions and Pain.
Cereb. Cortex
PUBLISHED: 08-21-2013
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Lateralization of the processing of positive and negative emotions and pain suggests an asymmetric distribution of the neurotransmitter systems regulating these functions between the left and right brain hemispheres. By virtue of their ability to selectively mediate euphoria, dysphoria, and pain, the ?-, ?-, and ?-opioid receptors and their endogenous ligands may subserve these lateralized functions. We addressed this hypothesis by comparing the levels of the opioid receptors and peptides in the left and right anterior cingulate cortex (ACC), a key area for emotion and pain processing. Opioid mRNAs and peptides and 5 "classical" neurotransmitters were analyzed in postmortem tissues from 20 human subjects. Leu-enkephalin-Arg (LER) and Met-enkephalin-Arg-Phe, preferential ?-/?- and ?-/?-opioid agonists, demonstrated marked lateralization to the left and right ACC, respectively. Dynorphin B (Dyn B) strongly correlated with LER in the left, but not in the right ACC suggesting different mechanisms of the conversion of this ?-opioid agonist to ?-/?-opioid ligand in the 2 hemispheres; in the right ACC, Dyn B may be cleaved by PACE4, a proprotein convertase regulating left-right asymmetry formation. These findings suggest that region-specific lateralization of neuronal networks expressing opioid peptides underlies in part lateralization of higher functions, including positive and negative emotions and pain in the human brain.
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Neurotoxin-Induced Neuropeptide Perturbations in Striatum of Neonatal Rats.
J. Proteome Res.
PUBLISHED: 03-05-2013
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The cyanobacterial toxin ?-N-methylamino-l-alanine (BMAA) is suggested to play a role in neurodegenerative disease. We have previously shown that although the selective uptake of BMAA in the rodent neonatal striatum does not cause neuronal cell death, exposure during the neonatal development leads to cognitive impairments in adult rats. The aim of the present study was to characterize the changes in the striatal neuropeptide systems of male and female rat pups treated neonatally (postnatal days 9-10) with BMAA (40-460 mg/kg). The label-free quantification of the relative levels of endogenous neuropeptides using mass spectrometry revealed that 25 peptides from 13 neuropeptide precursors were significantly changed in the rat neonatal striatum. The exposure to noncytotoxic doses of BMAA induced a dose-dependent increase of neurosecretory protein VGF-derived peptides, and changes in the relative levels of cholecystokinin, chromogranin, secretogranin, MCH, somatostatin and cortistatin-derived peptides were observed at the highest dose. In addition, the results revealed a sex-dependent increase in the relative level of peptides derived from the proenkephalin-A and protachykinin-1 precursors, including substance P and neurokinin A, in female pups. Because several of these peptides play a critical role in the development and survival of neurons, the observed neuropeptide changes might be possible mediators of BMAA-induced behavioral changes. Moreover, some neuropeptide changes suggest potential sex-related differences in susceptibility toward this neurotoxin. The present study also suggests that neuropeptide profiling might provide a sensitive characterization of the BMAA-induced noncytotoxic effects on the developing brain.
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Extensive characterization of Tupaia belangeri neuropeptidome using an integrated mass spectrometric approach.
J. Proteome Res.
PUBLISHED: 12-02-2011
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Neuropeptidomics is used to characterize endogenous peptides in the brain of tree shrews (Tupaia belangeri). Tree shrews are small animals similar to rodents in size but close relatives of primates, and are excellent models for brain research. Currently, tree shrews have no complete proteome information available on which direct database search can be allowed for neuropeptide identification. To increase the capability in the identification of neuropeptides in tree shrews, we developed an integrated mass spectrometry (MS)-based approach that combines methods including data-dependent, directed, and targeted liquid chromatography (LC)-Fourier transform (FT)-tandem MS (MS/MS) analysis, database construction, de novo sequencing, precursor protein search, and homology analysis. Using this integrated approach, we identified 107 endogenous peptides that have sequences identical or similar to those from other mammalian species. High accuracy MS and tandem MS information, with BLAST analysis and chromatographic characteristics were used to confirm the sequences of all the identified peptides. Interestingly, further sequence homology analysis demonstrated that tree shrew peptides have a significantly higher degree of homology to equivalent sequences in humans than those in mice or rats, consistent with the close phylogenetic relationship between tree shrews and primates. Our results provide the first extensive characterization of the peptidome in tree shrews, which now permits characterization of their function in nervous and endocrine system. As the approach developed fully used the conservative properties of neuropeptides in evolution and the advantage of high accuracy MS, it can be portable for identification of neuropeptides in other species for which the fully sequenced genomes or proteomes are not available.
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Neuropeptide profiling of the bovine hypothalamus: thermal stabilization is an effective tool in inhibiting post-mortem degradation.
Proteomics
PUBLISHED: 02-14-2011
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The hypothalamus is the central regulatory region of the brain that links the nervous system to the endocrine system via the pituitary gland. It synthesizes and secretes neuropeptide hormones, which in turn act to stimulate or inhibit the secretion of pituitary hormones. We have undertaken a detailed MS investigation of the peptides present in the bovine hypothalamus by adapting a novel heat stabilization methodology, which improved peptide discovery to direct our studies into the molecular mechanisms involved in bovine reproduction. The untreated samples contained large numbers of protein degradation products that interfered with the analysis of the neuropeptides. In the thermally stabilized samples, we were able to identify many more neuropeptides that are known to be expressed in the bovine hypothalamus. Furthermore, we have characterized a range of post-translational modifications that indicate the presence of processed intact mature neuropeptides in the stabilized tissue samples, whereas we detected many trimmed or truncated peptides resulting from post-mortem degradation in the untreated tissue samples. Altogether, using an optimized workflow, we were able to identify 140 candidate neuropeptides. We also nominate six new candidate neuropeptides derived from proSAAS, secretogranin-2 and proTRH.
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Proteomic profiling of the Baltic Sea cyanobacterium Nodularia spumigena strain AV1 during ammonium supplementation.
J Proteomics
PUBLISHED: 04-10-2010
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The cyanobacterium Nodularia spumigena dominates the annual, toxic summer blooms in the Baltic Sea. Although Nodularia has been receiving attention due to its production of the hepatotoxin nodularin, molecular data regarding the regulation of nitrogen fixation is lacking. We have previously reported that N. spumigena strain AV1, unlike model filamentous cyanobacteria, differentiates heterocysts in the absence of detectable nitrogen fixation activity. To further analyze the uncoupling between these two linked processes, we assessed the impact of ammonium ions on the N. spumigena metabolism using a proteomic approach. Proteomic profiling was performed at three different times during ammonium supplementation using quantitative 2-dimensional gel electrophoresis followed by MS/MS analysis. Using this approach, we identified 34 proteins, 28 of which were unique proteins that changed successively in abundance during growth on ammonium. Our results indicate that N. spumigena generally exhibits lower energy production and carbon fixation in the presence of ammonium and seems to be inefficient in utilizing ammonium as an external nitrogen source. The possibility of ammonium toxicity due to PSII damage was investigated and the results are discussed. Our findings have implications in regard to the strategies considered to manage the cyanobacterial blooms in the Baltic Sea.
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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.

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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.