| 1. |
- Nilsson, Anna, et al.
(författare)
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Striatal alterations of secretogranin-1, somatostatin, prodynorphin and cholecystokinin peptides in an experimental mouse model of Parkinson’s disease
- 2009
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 8:5, s. 1094-1104
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Tidskriftsartikel (refereegranskat)abstract
- The principal causative pathology of Parkinson disease is the progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta projecting to the striatum in the brain. The information regarding the expression of neuropeptides in parkinsonism is very limited. Here we have elucidated striatal neuropeptide mechanisms in experimental parkinsonism using the unilateral 6-hydroxydopamine model to degenerate dopamine neurons. A thoroughly controlled sample preparation technique together with a peptidomics approach and targeted neuropeptide sequence collections enabled sensitive detection, identification, and relative quantitation of a great number of endogenous neuropeptides. Previously not recognized alterations in neuropeptide levels were identified in the unilateral lesioned mice with or without subchronic 3,4-dihydroxy-L-phenylalanine administration, the conventional treatment of Parkinson disease. Several of these peptides originated from the same precursor such as secretogranin-1, somatostatin, prodynorphin, and cholecystokinin. Disease-related biotransformation of precursors into individual peptides was observed in the experimental model of Parkinson disease. Several previously unreported potentially biologically active peptides were also identified from the striatal samples. This study provides further evidence that neuropeptides take part in mediating the central nervous system failure associated with Parkinson disease.
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| 2. |
- Alm, Henrik, et al.
(författare)
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Exposure to brominated flame retardant PBDE-99 affects cytoskeletal protein expression in the neonatal mouse cerebral cortex
- 2008
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Ingår i: Neurotoxicology. - : Elsevier BV. - 0161-813X .- 1872-9711. ; 29:4, s. 628-637
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Tidskriftsartikel (refereegranskat)abstract
- Polybrominated diphenyl ethers (PBDEs) are environmental contaminants found in human and animal tissues worldwide. Neonatal exposure to the flame retardant 2,2', 4,4',5-pentabromodiphenyl ether (PBDE-99) disrupts normal brain development in mice, and results in disturbed spontaneous behavior in the adult. The mechanisms underlying the late effects of early exposure are not clear. To gain insight into the initial neurodevelopmental damage inflicted by PBDE-99, we investigated the short-term effects of PBDE-99 on protein expression in the developing cerebral cortex of neonatal mice, and the cytotoxic and apoptotic effects of PBDE-99 in primary cultures of fetal rat cortical cells. We used two-dimensional difference gel electrophoresis (2D-DIGE) to analyze protein samples isolated from the cortex of NMRI mice 24h after exposure to a single oral dose of 12 mg/kg PBDE-99 on post-natal day 10. Protein resolution was enhanced by sample pre-fractionation. In the cell model, we determined cell viability using the trypan blue exclusion assay, and apoptosis using immunocytochemical detection of cleaved caspase-3. We determined the identity of 111 differentially expressed proteins, 32 (29%) of which are known to be cytoskeleton-related. Similar to previous findings in the striatum, we found elevated levels of the neuron growth-associated protein Gap43 in the cortex. In cultured cortical cells, a high concentration of PBDE-99 (30 microM) induced cell death without any apparent increase in caspase-3 activity. These results indicate that the permanent neurological damage induced by PBDE-99 during the brain growth spurt involve detrimental effects on cytoskeletal regulation and neuronal maturation in the developing cerebral cortex.
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| 3. |
- Alm, Henrik, et al.
(författare)
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In Vitro Neurotoxicity of PBDE-99 : Immediate and Concentration-Dependent Effects on Protein Expression in Cerebral Cortex Cells
- 2010
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 9:3, s. 1226-1235
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Tidskriftsartikel (refereegranskat)abstract
- Polybrominated diphenyl ethers (PBDEs) are commonly used flame retardants in various consumer products. Pre- and postnatal exposure to congeners of PBDEs disrupts normal brain development in rodents. Two-dimensional difference gel electrophoresis (2D-DIGE) was used to analyze concentration-dependent differences in protein expression in cultured cortical cells isolated from rat fetuses (GD 21) after 24 h exposure to PBDE-99 (3, 10, or 30 muM). Changes on a post-translational level were studied using a 1 h exposure to 30 muM PBDE-99. The effects of 24 h exposure to 3 and 30 muM PBDE-99 on mRNA levels were measured using oligonucleotide microarrays. A total of 62, 46, and 443 proteins were differentially expressed compared to controls after 24 h of exposure to 3, 10, and 30 muM PDBE-99, respectively. Of these, 48, 43, and 238 proteins were successfully identified, respectively. We propose that the biological effects of low-concentration PBDE-99 exposure are fundamentally different than effects of high-concentration exposure. Low-dose PBDE-99 exposure induced marked effects on cytoskeletal proteins, which was not correlated to cytotoxicity or major morphological effects, suggesting that other more regulatory aspects of cytoskeletal functions may be affected. Interestingly, 0.3 and 3 muM, but not 10 or 30 muM increased the expression of phosphorylated (active) Gap43, perhaps reflecting effects on neurite extension processes.
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| 4. |
- Karlsson, Oskar, et al.
(författare)
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Neurotoxin-Induced Neuropeptide Perturbations in Striatum of Neonatal Rats
- 2013
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 12:4, s. 1678-1690
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Tidskriftsartikel (refereegranskat)abstract
- The cyanobacterial toxin β-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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| 5. |
- Kultima, Kim, et al.
(författare)
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Development and evaluation of normalization methods for label-free relative quantification of endogenous peptides
- 2009
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 8:10, s. 2285-2295
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Tidskriftsartikel (refereegranskat)abstract
- The performances of 10 different normalization methods on data of endogenous brain peptides produced with label-free nano-LC-MS were evaluated. Data sets originating from three different species (mouse, rat, and Japanese quail), each consisting of 35-45 individual LC-MS analyses, were used in the study. Each sample set contained both technical and biological replicates, and the LC-MS analyses were performed in a randomized block fashion. Peptides in all three data sets were found to display LC-MS analysis order-dependent bias. Global normalization methods will only to some extent correct this type of bias. Only the novel normalization procedure RegrRun (linear regression followed by analysis order normalization) corrected for this type of bias. The RegrRun procedure performed the best of the normalization methods tested and decreased the median S.D. by 43% on average compared with raw data. This method also produced the smallest fraction of peptides with interblock differences while producing the largest fraction of differentially expressed peaks between treatment groups in all three data sets. Linear regression normalization (Regr) performed second best and decreased median S.D. by 38% on average compared with raw data. All other examined methods reduced median S.D. by 20-30% on average compared with raw data.
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| 6. |
- Kultima, Kim, et al.
(författare)
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Normalization and expression changes in predefined sets of proteins using 2D gel electrophoresis : A proteomic study of L-DOPA induced dyskinesia in an animal model of Parkinson's disease using DIGE
- 2006
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Ingår i: BMC Bioinformatics. - : Springer Science and Business Media LLC. - 1471-2105. ; 7, s. 475-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Two-Dimensional Difference In Gel Electrophoresis (2D-DIGE) is a powerful tool for measuring differences in protein expression between samples or conditions. However, to remove systematic variability within and between gels the data has to be normalized. In this study we examined the ability of four existing and four novel normalization methods to remove systematic bias in data produced with 2D-DIGE. We also propose a modification of an existing method where the statistical framework determines whether a set of proteins shows an association with the predefined phenotypes of interest. This method was applied to our data generated from a monkey model (Macaca fascicularis) of Parkinson's disease. Results: Using 2D-DIGE we analysed the protein content of the striatum from 6 control and 21 MPTP-treated monkeys, with or without de novo or long-term L-DOPA administration. There was an intensity and spatial bias in the data of all the gels examined in this study. Only two of the eight normalization methods evaluated ('2D loess+scale' and 'SC-2D+quantile') successfully removed both the intensity and spatial bias. In 'SC-2D+quantile' we extended the commonly used loess normalization method against dye bias in two-channel microarray systems to suit systems with three or more channels. Further, by using the proposed method, Differential Expression in Predefined Proteins Sets (DEPPS), several sets of proteins associated with the priming effects of L-DOPA in the striatum in parkinsonian animals were identified. Three of these sets are proteins involved in energy metabolism and one set involved proteins which are part of the microtubule cytoskeleton. Conclusion: Comparison of the different methods leads to a series of methodological recommendations for the normalization and the analysis of data, depending on the experimental design. Due to the nature of 2D-DIGE data we recommend that the p-values obtained in significance tests should be used as rankings only. Individual proteins may be interesting as such, but by studying sets of proteins the interpretation of the results are probably more accurate and biologically informative.
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| 7. |
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| 8. |
- Scholz, Birger, et al.
(författare)
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Neuropeptidomic analysis of the embryonic Japanese quail diencephalon
- 2010
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Ingår i: BMC Developmental Biology. - 1471-213X. ; 10, s. 30-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Endogenous peptides such as neuropeptides are involved in numerous biological processes in the fully developed brain but very little is known about their role in brain development. Japanese quail is a commonly used bird model for studying sexual dimorphic brain development, especially adult male copulatory behavior in relation to manipulations of the embryonic endocrine system. This study uses a label-free liquid chromatography mass spectrometry approach to analyze the influence of age (embryonic days 12 vs 17), sex and embryonic day 3 ethinylestradiol exposure on the expression of multiple endogenous peptides in the developing diencephalon.Results: We identified a total of 65 peptides whereof 38 were sufficiently present in all groups for statistical analysis. Age was the most defining variable in the data and sex had the least impact. Most identified peptides were more highly expressed in embryonic day 17. The top candidates for EE2 exposure and sex effects were neuropeptide K (downregulated by EE2 in males and females), gastrin-releasing peptide (more highly expressed in control and EE2 exposed males) and gonadotropin-inhibiting hormone related protein 2 (more highly expressed in control males and displaying interaction effects between age and sex). We also report a new potential secretogranin-2 derived neuropeptide and previously unknown phosphorylations in the C-terminal flanking protachykinin 1 neuropeptide.Conclusions: This study is the first larger study on endogenous peptides in the developing brain and implies a previously unknown role for a number of neuropeptides in middle to late avian embryogenesis. It demonstrates the power of label-free liquid chromatography mass spectrometry to analyze the expression of multiple endogenous peptides and the potential to detect new putative peptide candidates in a developmental model.
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| 9. |
- Scholz, Birger, et al.
(författare)
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Striatal proteomic analysis suggests that first L-dopa dose equates to chronic exposure
- 2008
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 3:2, s. e1589-
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Tidskriftsartikel (refereegranskat)abstract
- L-3,4-dihydroxypheylalanine (L-dopa)-induced dyskinesia represent a debilitating complication of therapy for Parkinson's disease (PD) that result from a progressive sensitization through repeated L-dopa exposures. The MPTP macaque model was used to study the proteome in dopamine-depleted striatum with and without subsequent acute and chronic L-dopa treatment using two-dimensional difference in-gel electrophoresis (2D-DIGE) and mass spectrometry. The present data suggest that the dopamine-depleted striatum is so sensitive to de novo L-dopa treatment that the first ever administration alone would be able (i) to induce rapid post-translational modification-based proteomic changes that are specific to this first exposure and (ii), possibly, lead to irreversible protein level changes that would be not further modified by chronic L-dopa treatment. The apparent equivalence between first and chronic L-dopa administration suggests that priming would be the direct consequence of dopamine loss, the first L-dopa administrations only exacerbating the sensitization process but not inducing it.
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