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| 2. |
- Jeppsson, Marina, et al.
(författare)
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Identification of covalent binding sites of ethyl 2-cyanoacrylate, methyl methacrylate and 2-hydroxyethyl methacrylate in human hemoglobin using LC/MS/MS techniques.
- 2010
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Ingår i: Journal of Chromatography. B. - : Elsevier BV. - 1873-376X .- 1570-0232. ; 878, s. 2474-2482
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Tidskriftsartikel (refereegranskat)abstract
- Acrylates are used in vast quantities, for instance in paints, adhesive glues, molding. They are potent contact allergens and known to cause respiratory hypersensitivity and asthma. Here we study ethyl 2-cyanoacrylate (ECA), methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA). There are only limited possibilities to measure the exposure to acrylates, especially for biological monitoring. The aim of the present study was to investigate the chemical structures of adducts formed after reaction of hemoglobin (Hb) with ECA, MMA, and HEMA. This information may be used to identify adducted Hb peptides for biological monitoring of exposure to acrylates. Hb-conjugates with ECA, MMA, and HEMA were synthesized in vitro. The conjugates were digested by trypsin and pronase E. Adducted peptides were characterized and analyzed by liquid chromatography and nano electro spray/hybrid quadrupole time-of-flight mass spectrometry (MS) as well as tandem quadrupole MS. The search for the adducted peptides was facilitated by visualizing the MS data by different computer programs. The results showed that ECA binds covalently to cysteines at the 104 position in the alpha and the position 112 in the beta-chains in Hb. MMA and HEMA bound to all the cysteines in both chains, Cys(104) in the alpha-chain and Cys(93) and 112 in the beta-chain. The full-length spectra of in un-digested Hb confirmed this binding pattern. There was no reaction with N-acetyl-l-lysine at physiological pH. The adducted peptides were possible to measure using LC/MS/MS in selected reaction monitoring mode. These peptides may be used for biological monitoring of exposure to ECA, MMA and HEMA.
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| 3. |
- Kåredal, Monica, et al.
(författare)
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Time-Dependent Proteomic iTRAQ Analysis of Nasal Lavage of Hairdressers Challenged by Persulfate.
- 2010
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; okt, s. 5620-5628
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Tidskriftsartikel (refereegranskat)abstract
- Hairdressers are frequently exposed to bleaching powder containing persulfates, a group of compounds that may induce hypersensitivity in the airways. The mechanism causing this reaction is not clear. The aim of this study was to identify changes in the nasal lavage fluid proteome after challenge with potassium persulfate in hairdressers with bleaching powder-associated rhinitis. Furthermore, we aimed to compare their response to that of hairdressers without nasal symptoms, and atopic subjects with pollen-associated nasal symptoms. To study the pathogenesis of persulfate-associated rhinitis, the response in protein expression from the upper airway was assessed by time-dependent proteomic expression analysis of nasal lavage fluids. Samples were prepared by pooling nasal lavage fluids from the groups at different time points after challenge. Samples were depleted of high-abundant proteins, labeled with iTRAQ and analyzed by online 2D-nanoLC-MS/MS. Differences in the protein pattern between the three groups were observed. Most proteins with differentially expressed levels were involved in pathways of lipid transportation and antimicrobial activities. The major finding was increased abundance of apolipoprotein A-1, 20 min postchallenge, detected solely in the group of symptomatic hairdressers. Our results suggest there may be differences between the mechanisms responsible for the rhinitis in the symptomatic and atopic group.
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| 4. |
- Ljunggren, Stefan, et al.
(författare)
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Changes in Human Liportein Composition in Patients with Acute Coronary Syndrome
- 2011
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Ingår i: Atherosclerosis Supplements. - : Elsevier. - 1567-5688 .- 1878-5050. ; 12:1, s. 14-14
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The protein composition of lipoproteins may serve as biomarkers or reveal underlying mechanisms during different states of disease. Here we have analysed the protein composition of LDL and HDL from patients with acute coronary syndrome (ACS) and patients receiving statins after previous ACS. Plasma samples were obtained from males, namely 12 healthy donors, 9 patients with ACS and 7 stable patients receiving statin treatment after previous ACS. LDL and HDL were isolated by two-step density ultracentrifugation. LDL proteins were analysed with two-dimensional gel electrophoresis and mass spectrometry. Paraoxonase 1 (PON-1) in HDL was analyzed with SDSPAGE/Western Blot.Concentrations of apo A-IV, a1-antitrypsin and transthyretin were significantly increased (P < 0.05) in LDL from patients with ACS compared to healthy controls. In patients receiving statins, a1-antitrypsin remained increased while serum amyloid A4 was decreased. By western blot analysis, a non-significant increase in PON-1 was found in HDL from patients with ACS. Interestingly, a truncated form of PON-1 was detected in all patients with ACS but not in any of the controls.In conclusion, we confirm previous findings that LDL-associated transthyretin is a possible biomarker of myocardial infarction. Moreover, the increased concentration of the inflammatory marker a1-antitrypsin in LDL from both ACS patients and stable patients after ACS indicate that the enrichment does not only reflect an acute phase response. The presence of a truncated form of the antioxidant protein PON-1 in HDL may explain previous findings showing increased amounts but lower activity of PON-1 in patients with ACS.
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| 5. |
- Mörtstedt, Harriet
(författare)
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Proteomics in Nasal Lavage Fluids from Persulfate Challenged Hairdressers
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hairdressers have an increased risk for developing airway symptoms e.g. asthma and rhinitis. Persulfate salts, which are oxidizing agents present in bleaching powder, are considered to be important causal agents for these symptoms. The underlying mechanisms are unclear and efficient tools for risk assessment and diagnosis are scarce. The general aim of this thesis was to measure proteomic changes, both with respect to protein abundances and protein oxidation, in nasal lavage fluids (NLF) from hairdressers challenged with persulfates. Proteins regulate most biological processes in the human body. Changes in protein levels may therefore provide a better understanding of disease pathogenesis and/or candidate biomarkers for persulfate exposure, effect and/or oxidative stress. A high throughput screening method for quantification of 246 NLF proteins was developed using selected reaction monitoring (SRM). Also, a strategy for identification of multiple oxidative modifications was developed and applied on proteins oxidized in vitro by persulfate. SRM assays targeting the oxidized peptides were developed. NLF samples from a previous persulfate challenge study were analyzed. Hairdressers with bleaching powder associated rhinitis were compared to hairdressers without respiratory symptoms and with atopic subjects without work related exposure to persulfate. Protein abundances in the NLF samples were analyzed with two different proteomic approaches. Pooled samples were first analyzed with an untargeted approach using 2D-nanoLC-MS/MS combined with iTRAQ-labeling and then with the SRM method targeting 246 NLF proteins. Also, oxidized peptides were measured in the samples by SRM. Several proteins with biologically relevant functions were changed after the persulfate challenge. The exact role of these proteins in relation to persulfate-induced respiratory symptoms needs to be further studied as well as the usefulness of them as effect biomarkers. Persulfates oxidized tryptophan and methionine residues. It was concluded that oxidized peptides containing these modifications are not suitable as persulfate exposure biomarkers due to poor specificity. Peptides containing oxidized tryptophan may be useful as biomarkers for oxidative stress and should be further evaluated.
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| 6. |
- Mörtstedt, Harriet, et al.
(författare)
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Screening Method Using Selected Reaction Monitoring for Targeted Proteomics Studies of Nasal Lavage Fluid.
- 2012
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907.
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Tidskriftsartikel (refereegranskat)abstract
- Proteomic-based studies of nasal lavage fluid (NLF) may identify molecular pathways associated with disease pathology and new biomarker candidates of upper airway diseases. However, most studies have used rather tedious untargeted MS techniques. Selected reaction monitoring (SRM) is a sensitive and specific technique that can be used with high throughput. In this study, we developed a semiquantitative SRM-based method targeting 244 NLF proteins. The protein set was identified through a literature study in combination with untargeted LC-MS/MS analyses of trypsin-digested NLF samples. The SRM assays were designed using MS/MS data either downloaded from a proteomic data repository or experimentally obtained. Each protein is represented by one to five peptides, resulting in 708 SRM assays. Three to four transitions per assay were used to ensure analyte specificity. The majority (69%) of the assays showed good within-day precision (coefficient of variation ≤20%). The accuracy of the method was evaluated by analyzing four samples prepared with varying amounts of four proteins. Peptide and protein ratios were in good agreement with expected ratios. In conclusion, a high throughput screening method for relative quantification of 244 NLF proteins was developed. The method should be of general use in any proteomic study of the upper airways.
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| 7. |
- Mörtstedt, Harriet, et al.
(författare)
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Strategy for identification and detection of multiple oxidative modifications within proteins applied on persulfate-oxidized hemoglobin and human serum albumin.
- 2011
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Ingår i: Rapid Communications in Mass Spectrometry. - : Wiley. - 1097-0231 .- 0951-4198. ; 25:2, s. 327-340
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Tidskriftsartikel (refereegranskat)abstract
- Oxidative stress has been suggested as an underlying mechanism of many human diseases. However, definitive evidence for this association has not been presented due to different shortcomings of the methods used to measure biomarkers of oxidative stress. Persulfates are oxidizing agents known to elicit hypersensitive reactions from the airways and skin. Despite a frequent use of persulfates at many work places, no biomarkers for persulfate exposure are available. The aim of this study was to develop a strategy for the identification and detection of multiple oxidative modifications within proteins. This strategy was applied on persulfate-oxidized proteins to identify oxidized peptides suitable for further investigation as biomarkers of persulfate exposure or oxidative stress. A strategy for the identification and the relative quantification of multiple oxidative modifications within proteins was developed. The usage of two software packages facilitated the search for modified peptides to a great extent. Oxidized peptides were relatively quantified using liquid chromatography/tandem mass spectrometry in selected reaction monitoring mode. The result showed that persulfates oxidize tryptophans and methionines resulting in mass shifts of 16 and/or 32 Da. Also, oxidized albumin peptides in nasal lavage fluid samples from subjects challenged with persulfate were detected. The oxidation degree before and after challenge remained constant for peptides containing methionine sulfoxide. For peptides containing oxidized tryptophan the oxidation degree increased after exposure. Some of these oxidized peptides may be suitable as biomarkers; however, further evaluation is required.
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| 8. |
- Mörtstedt, Harriet, et al.
(författare)
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Targeted Proteomic Analyses of Nasal Lavage Fluid in Persulfate-Challenged Hairdressers with Bleaching Powder-Associated Rhinitis
- 2015
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 14:2, s. 860-873
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Tidskriftsartikel (refereegranskat)abstract
- Hairdressers have an increased risk for developing airway symptoms, for example, asthma and rhinitis. Persulfates, which are oxidizing agents in bleaching powder, are considered important causal agents for these symptoms. However, the underlying mechanisms are unclear. The aim was therefore to measure proteomic changes in nasal lavage fluid from persulfate-challenged subjects to identify proteins potentially involved in the pathogenesis of bleaching powder-associated rhinitis or candidate effect biomarkers for persulfate. Also, oxidized peptides were measured to evaluate their usefulness as biomarkers for persulfate exposure or effect, for example, oxidative stress. Samples from hairdressers with and without bleaching powder-associated rhinitis were analyzed with liquid chromatography tandem mass spectrometry using selected reaction monitoring to target 246 proteins and five oxidized peptides. Pathway analysis was applied to obtain a functional overview of the proteins. Several proteins involved in biologically meaningful pathways, functions, or disorders, for example, inflammatory responses, oxidative stress, epithelium integrity, and dermatological disorders, changed after the persulfate challenge. A list with nine proteins that appeared to be affected by the persulfate challenge and should be followed up was defined. An albumin peptide containing oxidized tryptophan increased 2 h and 5 h after the challenge but not after 20 min, which indicates that such peptides may be useful as oxidative stress biomarkers.
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