| 1. |
- Emami Khoonsari, Payam, et al.
(author)
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Analysis of the Cerebrospinal Fluid Proteome in Alzheimer's Disease
- 2016
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:3
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Journal article (peer-reviewed)abstract
- Alzheimer's disease is a neurodegenerative disorder accounting for more than 50% of cases of dementia. Diagnosis of Alzheimer's disease relies on cognitive tests and analysis of amyloid beta, protein tau, and hyperphosphorylated tau in cerebrospinal fluid. Although these markers provide relatively high sensitivity and specificity for early disease detection, they are not suitable for monitor of disease progression. In the present study, we used label-free shotgun mass spectrometry to analyse the cerebrospinal fluid proteome of Alzheimer's disease patients and non-demented controls to identify potential biomarkers for Alzheimer's disease. We processed the data using five programs (DecyderMS, Maxquant, OpenMS, PEAKS, and Sieve) and compared their results by means of reproducibility and peptide identification, including three different normalization methods. After depletion of high abundant proteins we found that Alzheimer's disease patients had lower fraction of low-abundance proteins in cerebrospinal fluid compared to healthy controls (p<0.05). Consequently, global normalization was found to be less accurate compared to using spiked-in chicken ovalbumin for normalization. In addition, we determined that Sieve and OpenMS resulted in the highest reproducibility and PEAKS was the programs with the highest identification performance. Finally, we successfully verified significantly lower levels (p<0.05) of eight proteins (A2GL, APOM, C1QB, C1QC, C1S, FBLN3, PTPRZ, and SEZ6) in Alzheimer's disease compared to controls using an antibody-based detection method. These proteins are involved in different biological roles spanning from cell adhesion and migration, to regulation of the synapse and the immune system.
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| 2. |
- Loza, M. J., et al.
(author)
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Validated and longitudinally stable asthma phenotypes based on cluster analysis of the ADEPT study
- 2016
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In: Respiratory Research. - : Springer Nature. - 1465-9921 .- 1465-993X. ; 17:1
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Journal article (peer-reviewed)abstract
- Background: Asthma is a disease of varying severity and differing disease mechanisms. To date, studies aimed at stratifying asthma into clinically useful phenotypes have produced a number of phenotypes that have yet to be assessed for stability and to be validated in independent cohorts. The aim of this study was to define and validate, for the first time ever, clinically driven asthma phenotypes using two independent, severe asthma cohorts: ADEPT and U-BIOPRED. Methods: Fuzzy partition-around-medoid clustering was performed on pre-specified data from the ADEPT participants (n = 156) and independently on data from a subset of U-BIOPRED asthma participants (n = 82) for whom the same variables were available. Models for cluster classification probabilities were derived and applied to the 12-month longitudinal ADEPT data and to a larger subset of the U-BIOPRED asthma dataset (n = 397). High and low type-2 inflammation phenotypes were defined as high or low Th2 activity, indicated by endobronchial biopsies gene expression changes downstream of IL-4 or IL-13. Results: Four phenotypes were identified in the ADEPT (training) cohort, with distinct clinical and biomarker profiles. Phenotype 1 was "mild, good lung function, early onset", with a low-inflammatory, predominantly Type-2, phenotype. Phenotype 2 had a "moderate, hyper-responsive, eosinophilic" phenotype, with moderate asthma control, mild airflow obstruction and predominant Type-2 inflammation. Phenotype 3 had a "mixed severity, predominantly fixed obstructive, non-eosinophilic and neutrophilic" phenotype, with moderate asthma control and low Type-2 inflammation. Phenotype 4 had a "severe uncontrolled, severe reversible obstruction, mixed granulocytic" phenotype, with moderate Type-2 inflammation. These phenotypes had good longitudinal stability in the ADEPT cohort. They were reproduced and demonstrated high classification probability in two subsets of the U-BIOPRED asthma cohort. Conclusions: Focusing on the biology of the four clinical independently-validated easy-to-assess ADEPT asthma phenotypes will help understanding the unmet need and will aid in developing tailored therapies. Trial registration:NCT01274507(ADEPT), registered October 28, 2010 and NCT01982162(U-BIOPRED), registered October 30, 2013.
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| 6. |
- Hamsten, C., et al.
(author)
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Protein profiles of CCL5, HPGDS, and NPSR1 in plasma reveal association with childhood asthma
- 2016
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In: Allergy. European Journal of Allergy and Clinical Immunology. - : Blackwell Publishing. - 0105-4538 .- 1398-9995. ; 71:9, s. 1357-1361
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Journal article (peer-reviewed)abstract
- Asthma is a common chronic childhood disease with many different phenotypes that need to be identified. We analyzed a broad range of plasma proteins in children with well-characterized asthma phenotypes to identify potential markers of childhood asthma. Using an affinity proteomics approach, plasma levels of 362 proteins covered by antibodies from the Human Protein Atlas were investigated in a total of 154 children with persistent or intermittent asthma and controls. After screening, chemokine ligand 5 (CCL5) hematopoietic prostaglandin D synthase (HPGDS) and neuropeptide S receptor 1 (NPSR1) were selected for further investigation. Significantly lower levels of both CCL5 and HPGDS were found in children with persistent asthma, while NPSR1 was found at higher levels in children with mild intermittent asthma compared to healthy controls. In addition, the protein levels were investigated in another respiratory disease, sarcoidosis, showing significantly higher NPSR1 levels in sera from sarcoidosis patients compared to healthy controls. Immunohistochemical staining of healthy tissues revealed high cytoplasmic expression of HPGDS in mast cells, present in stroma of both airway epithelia, lung as well as in other organs. High expression of NPSR1 was observed in neuroendocrine tissues, while no expression was observed in airway epithelia or lung. In conclusion, we have utilized a broad-scaled affinity proteomics approach to identify three proteins with altered plasma levels in asthmatic children, representing one of the first evaluations of HPGDS and NPSR1 protein levels in plasma.
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| 7. |
- Häggmark, Anna, et al.
(author)
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Plasma profiling revelas three proteins associated to amyotrophic lateral sclerosis
- 2014
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In: Annals of Clinical and Translational Neurology. - : Wiley. - 2328-9503. ; 1:8, s. 544-553
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Journal article (peer-reviewed)abstract
- OBJECTIVE: Amyotrophic lateral sclerosis (ALS) is the most common adult motor neuron disease leading to muscular paralysis and death within 3-5 years from onset. Currently, there are no reliable and sensitive markers able to substantially shorten the diagnosis delay. The objective of the study was to analyze a large number of proteins in plasma from patients with various clinical phenotypes of ALS in search for novel proteins or protein profiles that could serve as potential indicators of disease.METHODS: Affinity proteomics in the form of antibody suspension bead arrays were applied to profile plasma samples from 367 ALS patients and 101 controls. The plasma protein content was directly labeled and protein profiles obtained using 352 antibodies from the Human Protein Atlas targeting 278 proteins. A focused bead array was then built to further profile eight selected protein targets in all available samples.RESULTS: Disease-associated significant differences were observed and replicated for profiles from antibodies targeting the proteins: neurofilament medium polypeptide (NEFM), solute carrier family 25 (SLC25A20), and regulator of G-protein signaling 18 (RGS18).INTERPRETATION: Upon further validation in several independent cohorts with inclusion of a broad range of other neurological disorders as controls, the alterations of these three protein profiles in plasma could potentially provide new molecular markers of disease that contribute to the quest of understanding ALS pathology.
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| 8. |
- Kolmert, Johan, et al.
(author)
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Urinary Leukotriene E-4 and Prostaglandin D-2 Metabolites Increase in Adult and Childhood Severe Asthma Characterized by Type 2 Inflammation A Clinical Observational Study
- 2021
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In: American Journal of Respiratory and Critical Care Medicine. - NEW YORK, USA : AMER THORACIC SOC. - 1073-449X .- 1535-4970. ; 203:1, s. 37-53
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Journal article (peer-reviewed)abstract
- Rationale: New approaches are needed to guide personalized treatment of asthma. Objectives: To test if urinary eicosanoid metabolites can direct asthma phenotyping. Methods: Urinary metabolites of prostaglandins (PGs), cysteinyl leukotrienes (CysLTs), and isoprostanes were quantified in the U-BIOPRED (Unbiased Biomarkers for the Prediction of Respiratory Diseases Outcomes) study including 86 adults with mild-to-moderate asthma (MMA), 411 with severe asthma (SA), and 100 healthy control participants. Validation was performed internally in 302 participants with SA followed up after 12-18 months and externally in 95 adolescents with asthma. Measurement and Main Results: Metabolite concentrations in healthy control participants were unrelated to age, body mass index, and sex, except for the PGE(2) pathway. Eicosanoid concentrations were generally greater in participants with MMA relative to healthy control participants, with further elevations in participants with SA. However, PGE(2) metabolite concentrations were either the same or lower in male nonsmokers with asthma than in healthy control participants. Metabolite concentrations were unchanged in those with asthma who adhered to oral corticosteroid treatment as documented by urinary prednisolone detection, whereas those with SA treated with omalizumab had lower concentrations of LTE4 and the PGD(2) metabolite 2,3-dinor-11 beta-PGF(2 alpha). High concentrations of LTE4 and PGD(2) metabolites were associated with lower lung function and increased amounts of exhaled nitric oxide and eosinophil markers in blood, sputum, and urine in U-BIOARED participants and in adolescents with asthma. These type 2 (T2) asthma associations were reproduced in the follow-up visit of the U-BIOPRED study and were found to be as sensitive to detect T2 inflammation as the established biomarkers. Conclusions: Monitoring of urinary eicosanoids can identify T2 asthma and introduces a new noninvasive approach for molecular phenotyping of adult and adolescent asthma.
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| 9. |
- Lind, Anne-Li, et al.
(author)
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Affinity Proteomics Applied to Patient CSF Identifies Protein Profiles Associated with Neuropathic Pain and Fibromyalgia
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Other publication (other academic/artistic)abstract
- Objective: Today, there are no biological tests on which to base pain diagnoses, treatment choices or to understand the biological processes underlying and accompanying chronic pain for the individual pain patient. Relevant biological markers would greatly aid in diagnosis and treatment of patients with chronic pain. Our study aimed to find proteins in CSF associated with fibromyalgia and neuropathic pain, two common and poorly understood chronic pain conditions.Methods: We have performed CSF protein profiling of 55 proteins using a 100-plex antibody suspension bead array. We collected, analyzed and compared CSF samples from 25 patients with neuropathic pain (two independent sets, n=14 patients for discovery and n=11 for verification), 40 patients with fibromyalgia and 135 controls without neurological disease from two different populations.Results: We found significant differences in CSF protein levels between patients and controls (p<0.05). Among these proteins, Apolipoprotein C1 (APOC1) was found to be increased in CSF of neuropathic pain patients compared to controls and there was a non-significant trend for increased levels also in fibromyalgia patient CSF. Ectonucleotide pyrophosphatase (ENPP2, Autotaxin) was increased in the CSF of fibromyalgia patients compared to all other groups including neuropathic pain patients. Multivariate analysis revealed partially overlapping and partially distinct CSF profiles in neuropathic pain patients compared with fibromyalgia and controls for several other proteins including angiotensinogen (AGT), prostaglandin-H2 D-isomerase (PTGDS), neurexin-1 (NRXN1), superoxide dismutase 1 (SOD1) and superoxide dismutase 3 (SOD3).Conclusions: Our results, suggest that the CSF protein profiles of neuropathic pain and fibromyalgia patients may be different from each other and from those of controls. CSF levels of APOC1, ENPP2, AGT, PTGDS, NRXN1, SOD1 and SOD3 should be further investigated for their potential to serve as biomarkers of different kinds of pain pathophysiology.
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| 10. |
- Lind, Anne-Li, et al.
(author)
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CSF levels of apolipoprotein C1 and autotaxin found to associate with neuropathic pain and fibromyalgia
- 2019
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In: Journal of Pain Research. - : DOVE MEDICAL PRESS LTD. - 1178-7090. ; 12, s. 2875-2889
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Journal article (peer-reviewed)abstract
- Objective: Neuropathic pain and fibromyalgia are two common and poorly understood chronic pain conditions that lack satisfactory treatments, cause substantial suffering and societal costs. Today, there are no biological markers on which to base chronic pain diagnoses, treatment choices or to understand the pathophysiology of pain for the individual patient. This study aimed to investigate cerebrospinal fluid (CSF) protein profiles potentially associated with fibromyalgia and neuropathic pain. Methods: CSF samples were collected from 25 patients with neuropathic pain (two independent sets, n=14 patients for discovery, and n=11 for verification), 40 patients with fibromyalgia and 134 controls without neurological disease from two different populations. CSF protein profiling of 55 proteins was performed using antibody suspension bead array technology. Results: We found increased levels of apolipoprotein C1 (APOC1) in CSF of neuropathic pain patients compared to controls and there was a trend for increased levels also in fibromyalgia patients. In addition, levels of ectonucleotide pyrophosphatase family member 2 (ENPP2, also referred to as autotaxin) were increased in the CSF of fibromyalgia patients compared to all other groups including patients with neuropathic pain. Conclusion: The increased levels of APOC1 and ENPP2 found in neuropathic pain and fibromyalgia patients may shed light on the underlying mechanisms of these conditions. Further investigation is required to elucidate their role in maintaining pain and other main symptoms of these disorders.
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| 11. |
- Mikus, Maria, et al.
(author)
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Allergome-wide peptide microarrays enable epitope deconvolution in allergen-specific immunotherapy
- 2020
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In: Journal of Allergy and Clinical Immunology. - : Mosby Inc.. - 0091-6749 .- 1097-6825.
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Journal article (peer-reviewed)abstract
- Background: The interaction of allergens and allergen-specific IgE initiates the allergic cascade after crosslinking of receptors on effector cells. Antibodies of other isotypes may modulate such a reaction. Receptor crosslinking requires binding of antibodies to multiple epitopes on the allergen. Limited information is available on the complexity of the epitope structure of most allergens. Objectives: We sought to allow description of the complexity of IgE, IgG4, and IgG epitope recognition at a global, allergome-wide level during allergen-specific immunotherapy (AIT). Methods: We generated an allergome-wide microarray comprising 731 allergens in the form of more than 172,000 overlapping 16-mer peptides. Allergen recognition by IgE, IgG4, and IgG was examined in serum samples collected from subjects undergoing AIT against pollen allergy. Results: Extensive induction of linear peptide-specific Phl p 1– and Bet v 1–specific humoral immunity was demonstrated in subjects undergoing a 3-year-long AIT against grass and birch pollen allergy, respectively. Epitope profiles differed between subjects but were largely established already after 1 year of AIT, suggesting that dominant allergen-specific antibody clones remained as important contributors to humoral immunity following their initial establishment during the early phase of AIT. Complex, subject-specific patterns of allergen isoform and group cross-reactivities in the repertoires were observed, patterns that may indicate different levels of protection against different allergen sources. Conclusions: The study highlights the complexity and subject-specific nature of allergen epitopes recognized following AIT. We envisage that epitope deconvolution will be an important aspect of future efforts to describe and analyze the outcomes of AIT in a personalized manner.
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| 12. |
- Mikus, Maria, 1986-
(author)
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Array-based identification of disease-associated proteins
- 2018
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Doctoral thesis (other academic/artistic)abstract
- To increase our understanding of the human body in both health and disease, proteins can be studied in samples such as plasma and serum to provide a molecular profile of the physiological status. In the work presented in this thesis, array-based methods were used to study associations of protein and autoantibody profiles with disease. The methods included antibody suspension bead arrays for protein profiling and planar antigen arrays or antigen suspension bead arrays for autoantibody profiling.In Paper I, we studied protein levels in the context of the neurodegenerative disease amyotrophic lateral sclerosis (ALS). We identified three proteins, NEFM, RGS18 and SLC25A20, to be significantly elevated in patients with ALS. We also evaluated the diagnostic potential of these proteins, reaching areas under the curves (AUCs) between 0.78 and 0.86 for each of the three proteins individually.In Paper II, drug-induced liver injury (DILI) cases and controls were studied in four independent cohorts of longitudinal and cross-sectional design and covering a range of drugs. The protein FABP1 was elevated in DILI cases upon initiation of treatment whereas CDH5 were elevated before treatment. Furthermore, we compared FABP1 with the clinically measured alanine aminotransferase (ALT), and identified some aspects in which FABP1 was superior: tissue distribution – FABP1 was not found in skeletal and heart muscle tissue, injuries in which can cause elevations of ALT; kinetics – FABP1 is smaller and has a lower half-life compared to ALT. Both of these circumstances mean that FABP1 as a biomarker has the potential to more accurately reflect ongoing injury.In Paper III, asthma of different severities, chronic obstructive pulmonary disease and healthy controls from two independent cohorts were studied. The levels of ten proteins were verified to be significantly elevated in severe asthma compared to both mild-to-moderate asthma and healthy controls in both cohorts. We also clustered asthma patients based on their protein profiles and identified six subgroups that could help to guide the appropriate treatment.In Paper IV, atopic dermatitis (AD) of different severities and healthy controls were studied. Increased autoantibody reactivity to four antigens, KRTAP17-1, HSPA4, S100A12 and S100Z, were observed in AD patients or in any of the two severity disease subgroups compared to controls.In summary, the work included in this thesis highlights the applicability of protein array-based methods in various contexts and in studying various research questions. Disease-associated proteins were identified and further studies will determine their utility.
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| 14. |
- Mikus, Maria, et al.
(author)
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Elevated levels of circulating CDH5 and FABP1 in association with human drug-induced liver injury
- 2016
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In: Liver international. - : John Wiley & Sons. - 1478-3223 .- 1478-3231. ; 37:1, s. 132-140
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Journal article (peer-reviewed)abstract
- Background & Aims: The occurrence of drug-induced liver injury (DILI) is a major issue in all phases of drug development. To identify novel biomarker candidates associated with DILI, we utilised an affinity proteomics strategy, where antibody suspension bead arrays were applied to profile plasma and serum samples from human DILI cases and controls. Methods: An initial screening was performed using 4594 randomly selected antibodies, representing 3450 human proteins. Resulting candidate proteins together with proposed DILI biomarker candidates generated a DILI array of 251 proteins for subsequent target analysis and verifications. In total, 1196 samples from 241 individuals across four independent cohorts were profiled: healthy volunteers receiving acetaminophen, patients with human immunodeficiency virus and/or tuberculosis receiving treatment, DILI cases originating from a wide spectrum of drugs, and healthy volunteers receiving heparins. Results: We observed elevated levels of cadherin 5, type 2 (CDH5) and fatty acid-binding protein 1 (FABP1) in DILI cases. In the two longitudinal cohorts, CDH5 was elevated already at baseline. FABP1 was elevated after treatment initiation and seemed to respond more rapidly than alanine aminotransferase (ALT). The elevations were verified in the DILI cases treated with various drugs. In the heparin cohort, CDH5 was stable over time whereas FABP1 was elevated. Conclusions: These results suggest that CDH5 may have value as a susceptibility marker for DILI. FABP1 was identified as a biomarker candidate with superior characteristics regarding tissue distribution and kinetics compared to ALT but likely with limited predictive value for the development of severe DILI. Further studies are needed to determine the clinical utility of the proposed markers.
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| 17. |
- Mikus, Maria, et al.
(author)
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Protein profiles in plasma : Development from infancy to 5 years of age
- 2021
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In: PROTEOMICS - Clinical Applications. - : Wiley. - 1862-8346 .- 1862-8354. ; 15:4
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Journal article (peer-reviewed)abstract
- Purpose: Little is known about the longitudinal development of different plasma protein levels during early childhood and particularly in relation to lifestyle factors. This study aimed to monitor the plasma proteome early in life and the influence of different lifestyles. Experimental Design: A multiplex bead-based immunoassay was used to analyze plasma levels of 97 proteins in 280 blood samples longitudinally collected in children at 6, 12, 24, and 60 months of age living in families with an anthroposophic (n = 15), partly anthroposophic (n = 27), or non-anthroposophic (n = 28) lifestyle. Results: A total of 68 proteins (70%) showed significantly altered plasma levels between 6 months and 5 years of age. In lifestyle stratified analysis, 59 of 97 (61%) proteins were altered over time within one or more of the three lifestyle groups. Nearly half of these proteins (28 out of 59) changed irrespective of lifestyle. The temporal changes represented four longitudinal trends of the plasma proteins during development, also following stratification of lifestyle. Conclusions and Clinical Relevance: Our findings contribute to understand the development of the plasma proteome under the influence of lifestyle exposures in early childhood.
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| 19. |
- Mikus, Maria, et al.
(author)
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The antimicrobial protein S100A12 identified as a potential autoantigen in a subgroup of atopic dermatitis patients
- 2019
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In: Clinical and Translational Allergy. - : BioMed Central Ltd.. - 2045-7022. ; 9:1
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Journal article (peer-reviewed)abstract
- Background: Atopic dermatitis (AD) is a complex heterogeneous chronic inflammatory skin disease. Specific IgE antibodies against autoantigens have been observed in a subgroup of AD patients, however, little is known about IgG-auto-reactivity in AD. To investigate the presence of autoreactive IgG antibodies, we performed autoantibody profiling of IgG in patients with AD of different severities and in healthy controls (HC). Methods: First, we performed an untargeted screening in plasma samples from 40 severe AD (sAD) patients and 40 HC towards 1152 protein fragments on planar antigen microarrays. Next, based on the findings and addition of more fragments, a targeted antigen suspension bead array was designed to profile a cohort of 50 sAD patients, 123 patients with moderate AD (mAD), and 84 HC against 148 protein fragments representing 96 unique proteins. Results: Forty-nine percent of the AD patients showed increased IgG-reactivity to any of the four antigens representing keratin associated protein 17-1 (KRTAP17-1), heat shock protein family A (Hsp70) member 4 (HSPA4), S100 calcium binding proteins A12 (S100A12), and Z (S100Z). The reactivity was more frequent in the sAD patients (66%) than in those with mAD (41%), whereas only present in 25% of the HC. IgG-reactivity to S100A12, a protein including an antimicrobial peptide, was only observed in AD patients (13/173). Conclusions: Autoantibody profiling of IgG-reactivity using microarray technology revealed an autoantibody-based subgroup in patients with AD. The four identified autoantigens and especially S100A12 could, if characterized further, increase the understanding of different pathogenic mechanisms behind AD and thereby enable better treatment.
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| 20. |
- Sravani, Musunuri, 1987-, et al.
(author)
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Increased Levels of Extracellular Microvesicle Markers and Decreased Levels of Endocytic/Exocytic Proteins in the Alzheimer's Disease Brain
- 2016
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In: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 54:4, s. 1671-1686
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Journal article (peer-reviewed)abstract
- Background: Alzheimer's disease (AD) is a chronic neurodegenerative disorder accounting for more than 50% of all dementia cases. AD neuropathology is characterized by the formation of extracellular plaques and intracellular neurofibrillary tangles consisting of aggregated amyloid-beta and tau, respectively. The disease mechanism has only been partially elucidated and is believed to also involve many other proteins. Objective: This study intended to perform a proteomic profiling of post mortem AD brains and compare it with control brains as well as brains from other neurological diseases to gain insight into the disease pathology. Methods: Here we used label-free shotgun mass spectrometry to analyze temporal neocortex samples from AD, other neurological disorders, and non-demented controls, in order to identify additional proteins that are altered in AD. The mass spectrometry results were verified by antibody suspension bead arrays. Results: We found 50 proteins with altered levels between AD and control brains. The majority of these proteins were found at lower levels in AD. Pathway analyses revealed that several of the decreased proteins play a role in exocytic and endocytic pathways, whereas several of the increased proteins are related to extracellular vesicles. Using antibody-based analysis, we verified the mass spectrometry results for five representative proteins from this group of proteins (CD9, HSP72, PI42A, TALDO, and VAMP2) and GFAP, a marker for neuroinflammation. Conclusions: Several proteins involved in exo-endocytic pathways and extracellular vesicle functions display altered levels in the AD brain. We hypothesize that such changes may result in disturbed cellular clearance and a perturbed cell-to-cell communication that may contribute to neuronal dysfunction and cell death in AD.
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| 21. |
- Yasinska, Valentyna, et al.
(author)
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Low levels of endogenous anabolic androgenic steroids in females with severe asthma taking corticosteroids
- 2023
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In: ERJ Open Research. - : European Respiratory Society. - 2312-0541. ; 9:5
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Journal article (peer-reviewed)abstract
- Rationale: Patients with severe asthma are dependent upon treatment with high doses of inhaled corticosteroids (ICS) and often also oral corticosteroids (OCS). The extent of endogenous androgenic anabolic steroid (EAAS) suppression in asthma has not previously been described in detail. The objective of the present study was to measure urinary concentrations of EAAS in relation to exogenous corticosteroid exposure.Methods: Urine collected at baseline in the U-BIOPRED (Unbiased Biomarkers for the Prediction of Respiratory Disease outcomes) study of severe adult asthmatics (SA, n=408) was analysed by quantitative mass spectrometry. Data were compared to that of mild-to-moderate asthmatics (MMA, n=70) and healthy subjects (HC, n=98) from the same study.Measurements and main results: The concentrations of urinary endogenous steroid metabolites were substantially lower in SA than in MMA or HC. These differences were more pronounced in SA patients with detectable urinary OCS metabolites. Their dehydroepiandrosterone sulfate (DHEA-S) concentrations were <5% of those in HC, and cortisol concentrations were below the detection limit in 75% of females and 82% of males. The concentrations of EAAS in OCS-positive patients, as well as patients on high-dose ICS only, were more suppressed in females than males (p<0.05). Low levels of DHEA were associated with features of more severe disease and were more prevalent in females (p<0.05). The association between low EAAS and corticosteroid treatment was replicated in 289 of the SA patients at follow-up after 12–18 months.Conclusion: The pronounced suppression of endogenous anabolic androgens in females might contribute to sex differences regarding the prevalence of severe asthma.
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