Psoriatic Arthritis Under a Proteomic Spotlight: Application of Novel Technologies to Advance Diagnosis and Management

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Psoriatic arthritis is a form of inflammatory arthritis that is frequently associated with psoriasis. Individuals with this disease present with heterogeneous clinical manifestations, making it challenging to diagnose and select optimal treatment strategies. Perhaps, not unsurprisingly, there are currently no molecular diagnostic or prognostic tests to confirm if a patient has the disease or predict how they may respond to therapy. Instead, a range of classification criteria have been developed, and the experience of the treating clinician is heavily relied upon. It is therefore widely accepted that there is a significant and as yet unmet need for effective molecular markers in psoriatic arthritis. Protein mediators drive disease pathogenesis and, therefore, represent logical potential biomarkers. Indeed, significant advances have recently been made by the introduction of multiplexed protein biomarker tests for monitoring disease activity in rheumatoid arthritis. At the same time, recent advances in proteomics have enhanced the capabilities for the detection and discovery of protein biomarkers. These advances offer renewed opportunities for the development of multi-protein biomarker signatures to support clinical decision-making in the diagnosis, prognosis and treatment of psoriatic arthritis. This review summarises the pathogenesis of psoriatic arthritis, highlighting specific areas of unmet clinical need. Furthermore, it seeks to illustrate how the latest developments in proteomic technologies could be used to enhance our understanding of the molecular pathology of psoriatic arthritis and improve clinical outcomes and quality of life for patients.

Related collections

Most cited references 90

Record: found
Abstract: found
Article: not found

Quantitative analysis of complex protein mixtures using isotope-coded affinity tags.

S P Gygi, B Rist, S Gerber … (1999)

We describe an approach for the accurate quantification and concurrent sequence identification of the individual proteins within complex mixtures. The method is based on a class of new chemical reagents termed isotope-coded affinity tags (ICATs) and tandem mass spectrometry. Using this strategy, we compared protein expression in the yeast Saccharomyces cerevisiae, using either ethanol or galactose as a carbon source. The measured differences in protein expression correlated with known yeast metabolic function under glucose-repressed conditions. The method is redundant if multiple cysteinyl residues are present, and the relative quantification is highly accurate because it is based on stable isotope dilution techniques. The ICAT approach should provide a widely applicable means to compare quantitatively global protein expression in cells and tissues.

0 comments Cited 470 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Absolute quantification of proteins and phosphoproteins from cell lysates by tandem MS.

S Gerber, J. Rush, O. Stemman … (2003)

A need exists for technologies that permit the direct quantification of differences in protein and posttranslationally modified protein expression levels. Here we present a strategy for the absolute quantification (termed AQUA) of proteins and their modification states. Peptides are synthesized with incorporated stable isotopes as ideal internal standards to mimic native peptides formed by proteolysis. These synthetic peptides can also be prepared with covalent modifications (e.g., phosphorylation, methylation, acetylation, etc.) that are chemically identical to naturally occurring posttranslational modifications. Such AQUA internal standard peptides are then used to precisely and quantitatively measure the absolute levels of proteins and posttranslationally modified proteins after proteolysis by using a selected reaction monitoring analysis in a tandem mass spectrometer. In the present work, the AQUA strategy was used to (i) quantify low abundance yeast proteins involved in gene silencing, (ii) quantitatively determine the cell cycle-dependent phosphorylation of Ser-1126 of human separase protein, and (iii) identify kinases capable of phosphorylating Ser-1501 of separase in an in vitro kinase assay. The methods described here represent focused, alternative approaches for studying the dynamically changing proteome.

0 comments Cited 269 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Comparison of label-free methods for quantifying human proteins by shotgun proteomics.

William Old, Karen Meyer-Arendt, Lauren D Aveline-Wolf … (2005)

Measurements of mass spectral peak intensities and spectral counts are promising methods for quantifying protein abundance changes in shotgun proteomic analyses. We describe Serac, software developed to evaluate the ability of each method to quantify relative changes in protein abundance. Dynamic range and linearity using a three-dimensional ion trap were tested using standard proteins spiked into a complex sample. Linearity and good agreement between observed versus expected protein ratios were obtained after normalization and background subtraction of peak area intensity measurements and correction of spectral counts to eliminate discontinuity in ratio estimates. Peak intensity values useful for protein quantitation ranged from 10(7) to 10(11) counts with no obvious saturation effect, and proteins in replicate samples showed variations of less than 2-fold within the 95% range (+/-2sigma) when >or=3 peptides/protein were shared between samples. Protein ratios were determined with high confidence from spectral counts when maximum spectral counts were >or=4 spectra/protein, and replicates showed equivalent measurements well within 95% confidence limits. In further tests, complex samples were separated by gel exclusion chromatography, quantifying changes in protein abundance between different fractions. Linear behavior of peak area intensity measurements was obtained for peptides from proteins in different fractions. Protein ratios determined by spectral counting agreed well with those determined from peak area intensity measurements, and both agreed with independent measurements based on gel staining intensities. Overall spectral counting proved to be a more sensitive method for detecting proteins that undergo changes in abundance, whereas peak area intensity measurements yielded more accurate estimates of protein ratios. Finally these methods were used to analyze differential changes in protein expression in human erythroleukemia K562 cells stimulated under conditions that promote cell differentiation by mitogen-activated protein kinase pathway activation. Protein changes identified with p<0.1 showed good correlations with parallel measurements of changes in mRNA expression.