| 1. |
- Andersson, Annika, et al.
(författare)
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Development of parallel reaction monitoring assays for cerebrospinal fluid proteins associated with Alzheimer's disease
- 2019
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Ingår i: Clinica Chimica Acta. - : Elsevier B.V.. - 0009-8981 .- 1873-3492. ; 494, s. 79-93
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Tidskriftsartikel (refereegranskat)abstract
- Detailed knowledge of protein changes in cerebrospinal fluid (CSF) across healthy and diseased individuals would provide a better understanding of the onset and progression of neurodegenerative disorders. In this study, we selected 20 brain-enriched proteins previously identified in CSF by antibody suspension bead arrays (SBA) to be potentially biomarkers for Alzheimer's disease (AD) and verified these using an orthogonal approach. We examined the same set of 94 CSF samples from patients affected by AD (including preclinical and prodromal), mild cognitive impairment (MCI), non-AD dementia and healthy individuals, which had previously been analyzed by SBA. Twenty-eight parallel reaction monitoring (PRM) assays were developed and 13 of them could be validated for protein quantification. Antibody profiles were verified by PRM. For seven proteins, the antibody profiles were highly correlated with the PRM results (r > 0.7) and GAP43, VCAM1 and PSAP were identified as potential markers of preclinical AD. In conclusion, we demonstrate the usefulness of targeted mass spectrometry as a tool for the orthogonal verification of antibody profiling data, suggesting that these complementary methods can be successfully applied for comprehensive exploration of CSF protein levels in neurodegenerative disorders.
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| 2. |
- Bruzelius, Maria, et al.
(författare)
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PDGFB, a new candidate plasma biomarker for venous thromboembolism : results from the VEREMA affinity proteomics study
- 2016
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 128:23, s. E59-E66
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Tidskriftsartikel (refereegranskat)abstract
- There is a clear clinical need for high-specificity plasma biomarkers for predicting risk of venous thromboembolism (VTE), but thus far, such markers have remained elusive. Utilizing affinity reagents from the Human Protein Atlas project and multiplexed immuoassays, we extensively analyzed plasma samples from 2 individual studies to identify candidate protein markers associated with VTE risk. We screened plasma samples from 88 VTE cases and 85 matched controls, collected as part of the Swedish Venous Thromboembolism Biomarker Study, using suspension bead arrays composed of 755 antibodies targeting 408 candidate proteins. We identified significant associations between VTE occurrence and plasma levels of human immunodeficiency virus type I enhancer binding protein 1 (HIVEP1), von Willebrand factor (VWF), glutathione peroxidase 3 (GPX3), and platelet-derived growth factor beta (PDGFB). For replication, we profiled plasma samples of 580 cases and 589 controls from the French FARIVE study. These results confirmed the association of VWF and PDGFB with VTE after correction for multiple testing, whereas only weak trends were observed for HIVEP1 and GPX3. Although plasma levels of VWF and PDGFB correlated modestly (rho similar to 0.30) with each other, they were independently associated with VTE risk in a joint model in FARIVE (VWF P < .001; PDGFB P = .002). PDGF. was verified as the target of the capture antibody by immunocapture mass spectrometry and sandwich enzyme-linked immunosorbent assay. In conclusion, we demonstrate that high-throughput affinity plasma proteomic profiling is a valuable research strategy to identify potential candidate biomarkers for thrombosis-related disorders, and our study suggests a novel association of PDGFB plasma levels with VTE.
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| 3. |
- Byström, Sanna
(författare)
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Affinity assays for profiling disease-associated proteins in human plasma
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Affinity-based proteomics offers opportunities for the discovery and validation of disease-associated proteins in human body fluids. This thesis describes the use of antibody-based immunoassays for multiplexed analysis of proteins in human plasma, serum and cerebrospinal fluid (CSF). This high-throughput method was applied with the objective to identify proteins associated to clinical variables. The main work in this thesis was conducted within the diseases of multiple sclerosis and malignant melanoma, as well as mammographic density, a risk factor for breast cancer.The suspension bead array (SBA) technology has been the main method for the work presented in this thesis (Paper I-IV). SBA assays and other affinity proteomic technologies were introduced for protein profiling of sample material obtained from clinical collaborators and biobanks. Perspectives on the validation of antibody selectivity by means of e.g. immuno-capture mass spectrometry are also provided.Paper I describes the development and application of a protocol for multiplexed pro- tein profiling of CSF. The analysis of 340 CSF samples from patients with multiple sclerosis and other neurological disease revealed proteins with potential association to disease progression (GAP43) and inflammation (SERPINA3). Paper II continued on this work with an extended investigation of more than 1,000 clinical samples and included both plasma and CSF collected from the same patients. Comparison of disease subtypes and controls revealed five plasma proteins of potential diagnostic relevance, such as IRF8 and GAP43. The previously reported associations for GAP43 and SERPINA3 in CSF was confirmed. Subsequent immunohistochemical analysis of post-mortem brain tissue revealed differential protein expression in disease affected areas. In Paper III, 150 serum samples from patients with cutaneous malignant melanoma were analyzed. Protein profiles from antibody bead arrays suggested three proteins (RGN, MTHFD1L, STX7) of differential abundance between patients with no disease recurrence and low tumor thickness (T-stage 1 and 2) compared to patients with high tumor thickness (T-stage 3 and 4) and disease recurrence. We observed MTHFD1L expression in tissue of a majority of patients, while expression of STX7 in melanoma tissue had been reported previously. Paper IV describes the analysis of protein in plasma in relation to mammographic breast density (MD), one of the strongest risk factors for the development of breast cancers. More than 1,300 women without prior history of breast cancer were screened. Linear associations to MD in two independent sample sets were found for 11 proteins, which are expressed in the breast and involved in tissue homeostasis, DNA repair, cancer development and/or progression in MD.In conclusion, this thesis describes the use of multiplexed antibody bead arrays for protein profiling of serum, plasma and CSF, and it shortlists disease associated proteins for further validation studies.
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| 4. |
- Byström, Sanna, et al.
(författare)
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Affinity proteomic profiling of plasma for proteins associated to area-based mammographic breast density
- 2018
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Ingår i: Breast Cancer Research. - : BIOMED CENTRAL LTD. - 1465-5411 .- 1465-542X. ; 20
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Tidskriftsartikel (refereegranskat)abstract
- Background: Mammographic breast density is one of the strongest risk factors for breast cancer, but molecular understanding of how breast density relates to cancer risk is less complete. Studies of proteins in blood plasma, possibly associated with mammographic density, are well-suited as these allow large-scale analyses and might shed light on the association between breast cancer and breast density. Methods: Plasma samples from 1329 women in the Swedish KARMA project, without prior history of breast cancer, were profiled with antibody suspension bead array (SBA) assays. Two sample sets comprising 729 and 600 women were screened by two different SBAs targeting a total number of 357 proteins. Protein targets were selected through searching the literature, for either being related to breast cancer or for being linked to the extracellular matrix. Association between proteins and absolute area-based breast density (AD) was assessed by quantile regression, adjusting for age and body mass index (BMI). Results: Plasma profiling revealed linear association between 20 proteins and AD, concordant in the two sets of samples (p < 0.05). Plasma levels of seven proteins were positively associated and 13 proteins negatively associated with AD. For eleven of these proteins evidence for gene expression in breast tissue existed. Among these, ABCC11, TNFRSF10D, F11R and ERRF were positively associated with AD, and SHC1, CFLAR, ACOX2, ITGB6, RASSF1, FANCD2 and IRX5 were negatively associated with AD. Conclusions: Screening proteins in plasma indicates associations between breast density and processes of tissue homeostasis, DNA repair, cancer development and/or progression in breast cancer. Further validation and follow-up studies of the shortlisted protein candidates in independent cohorts will be needed to infer their role in breast density and its progression in premenopausal and postmenopausal women.
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| 5. |
- Byström, Sanna, et al.
(författare)
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Affinity Proteomics Exploration of Melanoma Identifies Proteins in Serum with Associations to T-Stage and Recurrence
- 2017
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Ingår i: Translational Oncology. - : Neoplasia Press, Inc.. - 1944-7124 .- 1936-5233. ; 10:3, s. 385-395
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Blood-based proteomic profiling may aid and expand our understanding of diseases and their different phenotypes. The aim of the presented study was to profile serum samples from patients with malignant melanoma using affinity proteomic assays to describe proteins in the blood stream that are associated to stage or recurrence of melanoma. MATERIAL AND METHODS: Multiplexed protein analysis was conducted using antibody suspension bead arrays. A total of 232 antibodies against 132 proteins were selected from (i) a screening with 4595 antibodies and 32 serum samples from melanoma patients and controls, (ii) antibodies used for immunohistochemistry, (iii) protein targets previously related with melanoma. The analysis was performed with 149 serum samples from patients with malignant melanoma. Antibody selectivity was then assessed by Western blot, immunocapture mass spectrometry, and epitope mapping. Lastly, indicative antibodies were applied for IHC analysis of melanoma tissues. RESULTS: Serum levels of regucalcin (RGN) and syntaxin 7 (STX7) were found to be lower in patients with both recurring tumors and a high Breslow's thickness (T-stage 3/4) compared to low thickness (T-stage 1/2) without disease recurrence. Serum levels of methylenetetrahydrofolate dehydrogenase 1-like (MTHFD1L) were instead elevated in sera of T3/4 patients with recurrence. The analysis of tissue sections with S100A6 and MTHFD1L showed positive staining in a majority of patients with melanoma, and S100A6 was significantly associated to T-stage. CONCLUSIONS: Our findings provide a starting point to further study RGN, STX7, MTHFD1L and S100A6 in serum to elucidate their involvement in melanoma progression and to assess a possible contribution to support clinical indications.
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| 6. |
- Drobin, Kimi, et al.
(författare)
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Targeted Analysis of Serum Proteins Encoded at Known Inflammatory Bowel Disease Risk Loci
- 2019
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Ingår i: Inflammatory Bowel Diseases. - : Oxford University Press. - 1078-0998 .- 1536-4844. ; 25:2, s. 306-316
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Tidskriftsartikel (refereegranskat)abstract
- Background: Few studies have investigated the blood proteome of inflammatory bowel disease (IBD). We characterized the serum abundance of proteins encoded at 163 known IBD risk loci and tested these proteins for their biomarker discovery potential.Methods: Based on the Human Protein Atlas (HPA) antibody availability, 218 proteins from genes mapping at 163 IBD risk loci were selected. Targeted serum protein profiles from 49 Crohn's disease (CD) patients, 51 ulcerative colitis (UC) patients, and 50 sex- and age-matched healthy individuals were obtained using multiplexed antibody suspension bead array assays. Differences in relative serum abundance levels between disease groups and controls were examined. Replication was attempted for CD-UC comparisons (including disease subtypes) by including 64 additional patients (33 CD and 31 UC). Antibodies targeting a potentially novel risk protein were validated by paired antibodies, Western blot, immuno-capture mass spectrometry, and epitope mapping.Results: By univariate analysis, 13 proteins mostly related to neutrophil, T-cell, and B-cell activation and function were differentially expressed in IBD patients vs healthy controls, 3 in CD patients vs healthy controls and 2 in UC patients vs healthy controls (q < 0.01). Multivariate analyses further differentiated disease groups from healthy controls and CD subtypes from UC (P < 0.05). Extended characterization of an antibody targeting a novel, discriminative serum marker, the laccase (multicopper oxidoreductase) domain containing 1 (LACC1) protein, provided evidence for antibody on-target specificity.Conclusions: Using affinity proteomics, we identified a set of IBD-associated serum proteins encoded at IBD risk loci. These candidate proteins hold the potential to be exploited as diagnostic biomarkers of IBD.
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| 7. |
- Edfors, Fredrik, et al.
(författare)
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Screening a Resource of Recombinant Protein Fragments for Targeted Proteomics
- 2019
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 18:7, s. 2706-2718
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Tidskriftsartikel (refereegranskat)abstract
- The availability of proteomics resources hosting protein and peptide standards, as well as the data describing their analytical performances, will continue to enhance our current capabilities to develop targeted proteomics methods for quantitative biology. This study describes the analysis of a resource of 26,840 individually purified recombinant protein fragments corresponding to more than 16,000 human protein-coding genes. The resource was screened to identify proteotypic peptides suitable for targeted proteomics efforts, and we report LC-MS/MS assay coordinates for more than 25,000 proteotypic peptides, corresponding to more than 10,000 unique proteins. Additionally, peptide formation and digestion kinetics were, for a subset of the standards, monitored using a time-course protocol involving parallel digestion of isotope-labeled recombinant protein standards and endogenous human plasma proteins. We show that the strategy by adding isotope-labeled recombinant proteins before trypsin digestion enables short digestion protocols (<= 60 min) with robust quantitative precision. In a proof-of-concept study, we quantified 23 proteins in human plasma using assay parameters defined in our study and used the standards to describe distinct clusters of individuals linked to different levels of LPA, APOE, SERPINAS, and TFRC. In summary, we describe the use and utility of a resource of recombinant proteins to identify proteotypic peptides useful for targeted proteomics assay development.
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| 8. |
- Fredolini, Claudia, et al.
(författare)
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Immunocapture strategies in translational proteomics
- 2016
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Ingår i: Expert Review of Proteomics. - : Taylor & Francis. - 1478-9450 .- 1744-8387. ; 13:1, s. 83-98
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Forskningsöversikt (refereegranskat)abstract
- Aiming at clinical studies of human diseases, antibody-assisted assays have been applied to biomarker discovery and toward a streamlined translation from patient profiling to assays supporting personalized treatments. In recent years, integrated strategies to couple and combine antibodies with mass spectrometry-based proteomic efforts have emerged, allowing for novel possibilities in basic and clinical research. Described in this review are some of the field's current and emerging immunocapture approaches from an affinity proteomics perspective. Discussed are some of their advantages, pitfalls and opportunities for the next phase in clinical and translational proteomics.
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| 9. |
- Fredolini, Claudia, et al.
(författare)
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Systematic assessment of antibody selectivity in plasma based on a resource of enrichment profiles
- 2019
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- There is a strong need for procedures that enable context and application dependent validation of antibodies. Here, we applied a magnetic bead assisted workflow and immunoprecipitation mass spectrometry (IP-MS/MS) to assess antibody selectivity for the detection of proteins in human plasma. A resource was built on 414 IP experiments using 157 antibodies (targeting 120 unique proteins) in assays with heat-treated or untreated EDTA plasma. For each protein we determined their antibody related degrees of enrichment using z-scores and their frequencies of identification across all IP assays. Out of 1,313 unique endogenous proteins, 426 proteins (33%) were detected in >20% of IPs, and these background components were mainly comprised of proteins from the complement system. For 45% (70/157) of the tested antibodies, the expected target proteins were enriched (z-score >= 3). Among these 70 antibodies, 59 (84%) co-enriched other proteins beside the intended target and mainly due to sequence homology or protein abundance. We also detected protein interactions in plasma, and for IGFBP2 confirmed these using several antibodies and sandwich immunoassays. The protein enrichment data with plasma provide a very useful and yet lacking resource for the assessment of antibody selectivity. Our insights will contribute to a more informed use of affinity reagents for plasma proteomics assays.
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| 10. |
- Häussler, Ragna S., et al.
(författare)
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Systematic Development of Sandwich Immunoassays for the Plasma Secretome
- 2019
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Ingår i: Proteomics. - : Wiley. - 1615-9853 .- 1615-9861.
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Tidskriftsartikel (refereegranskat)abstract
- The plasma proteome offers a clinically useful window into human health. Recent advances from highly multiplexed assays now call for appropriate pipelines to validate individual candidates. Here, a workflow is developed to build dual binder sandwich immunoassays (SIA) and for proteins predicted to be secreted into plasma. Utilizing suspension bead arrays, ≈1800 unique antibody pairs are first screened against 209 proteins with recombinant proteins as well as EDTA plasma. Employing 624 unique antibodies, dilution-dependent curves in plasma and concentration-dependent curves of full-length proteins for 102 (49%) of the targets are obtained. For 22 protein assays, the longitudinal, interindividual, and technical performance is determined in a set of plasma samples collected from 18 healthy subjects every third month over 1 year. Finally, 14 of these assays are compared with with SIAs composed of other binders, proximity extension assays, and affinity-free targeted mass spectrometry. The workflow provides a multiplexed approach to screen for SIA pairs that suggests using at least three antibodies per target. This design is applicable for a wider range of targets of the plasma proteome, and the assays can be applied for discovery but also to validate emerging candidates derived from other platforms.
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