scholarly journals Plasma proteomic analysis of systemic lupus erythematosus patients using liquid chromatography/tandem mass spectrometry with label-free quantification

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4730 ◽  
Author(s):  
Rashmi Madda ◽  
Shih-Chang Lin ◽  
Wei-Hsin Sun ◽  
Shir-Ly Huang

Context Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease with unknown etiology. Objective Human plasma is comprised of over 10 orders of magnitude concentration of proteins and tissue leakages. The changes in the abundance of these proteins have played an important role in various human diseases. Therefore, the research objective of this study is to identify the significantly altered expression levels of plasma proteins from SLE patients compared with healthy controls using proteomic analysis. The plasma proteome profiles of both SLE patients and controls were compared. Methods A total of 19 active SLE patients and 12 healthy controls plasma samples were analyzed using high-resolution electrospray ionization liquid chromatography-tandem mass spectrometry (LC-ESI-MS/MS) followed by label-free quantification. Results A total of 19 proteins showed a significant level of expression in the comparative LC-ESI-MS/MS triplicate analysis; among these, 14 proteins had >1.5- to three-fold up-regulation and five had <0.2- to 0.6-fold down-regulation. Gene ontology and DAVID (Database Annotation Visualization, and Integrated Discovery) functional enrichment analysis revealed that these proteins are involved in several important biological processes including acute phase inflammatory responses, complement activation, hemostasis, and immune system regulation. Conclusion Our study identified a group of differentially expressed proteins in the plasma of SLE patients that are involved in the imbalance of the immune system and inflammatory responses. Therefore, these findings may have the potential to be used as prognostic/diagnostic markers for SLE disease assessment or disease monitoring.

2013 ◽  
Vol 18 (8) ◽  
pp. 868-878 ◽  
Author(s):  
Michel C. Maillard ◽  
Celia Dominguez ◽  
Mark J. Gemkow ◽  
Florian Krieger ◽  
Hyunsun Park ◽  
...  

The resurgence of interest in caspases (Csp) as therapeutic targets for the treatment of neurodegenerative diseases prompted us to examine the suitability of published nonpeptidic Csp-3 and Csp-6 inhibitors for our medicinal chemistry programs. To support this effort, fluorescence-based Csp-2, Csp-3, and Csp-6 enzymatic assays were optimized for robustness against apparent enzyme inhibition caused by redox-cycling or aggregating compounds. The data obtained under these improved conditions challenge the validity of previously published data on Csp-3 and Csp-6 inhibitors for all but one series, namely, the isatins. Furthermore, in this series, it was observed that the nature of the rhodamine-labeled substrate, typically used to measure caspase activity, interfered with the pharmacological sensitivity of the Csp-2 assay. As a result, a liquid chromatography/tandem mass spectrometry–based assay that eliminates label-dependent assay interference was developed for Csp-2 and Csp-3. In these label-free assays, the activity values of the Csp-2 and Csp-3 reference inhibitors were in agreement with those obtained with the fluorogenic substrates. However, isatin 10a was 50-fold less potent in the label-free Csp-2 assay compared with the rhodamine-based fluorescence format, thus proving the need for an orthogonal readout to validate inhibitors in this class of targets highly susceptible to artifactual inhibition.


2020 ◽  
Vol 32 (6) ◽  
pp. 572 ◽  
Author(s):  
Mariana Diel de Amorim ◽  
Firdous A. Khan ◽  
Tracey S. Chenier ◽  
Elizabeth L. Scholtz ◽  
M. Anthony Hayes

The objective of this study was to evaluate the differences in the uterine flush fluid proteome between healthy mares and mares with endometritis or fibrotic endometrial degeneration (FED). Uterine flush fluid samples were collected from healthy mares (n=8; oestrus n=5 and dioestrus n=3) and mares with endometritis (n=23; oestrus n=14 and dioestrus n=9) or FED (n=7; oestrus n=6 and dioestrus n=1). Proteomic analysis was performed using label-free liquid chromatography–tandem mass spectrometry. Of 216 proteins identified during oestrus, 127 were common to all three groups, one protein was exclusively detected in healthy mares, 47 proteins were exclusively detected in mares with endometritis and four proteins were exclusively detected in mares with FED. Of 188 proteins identified during dioestrus, 113 proteins were common between healthy mares and mares with endometritis, eight proteins were exclusively detected in healthy mares and 67 proteins were exclusively detected in mares with endometritis. Quantitative analysis revealed a subset of proteins differing in abundance between the three groups during oestrus and between healthy mares and mares with endometritis during dioestrus. These results provide a springboard for evaluation of specific proteins as biomarkers of uterine health and disease and for investigation of their roles in the establishment and maintenance of pregnancy.


PROTEOMICS ◽  
2011 ◽  
Vol 11 (3) ◽  
pp. 495-500 ◽  
Author(s):  
Divya Krishnamurthy ◽  
Yishai Levin ◽  
Laura W. Harris ◽  
Yagnesh Umrania ◽  
Sabine Bahn ◽  
...  

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