Urine proteome scans uncover total urinary protease, prostaglandin D synthase, serum amyloid P, and superoxide dismutase as potential markers of lupus nephritis.
To identify potential biomarkers in immune-mediated nephritis, urine from mice subjected to an augmented passive model of anti-glomerular basement membrane (GBM)-induced experimental nephritis was resolved using two-dimensional gels. The urinary proteome in these diseased mice was comprised of at least 71 different proteins. Using orthogonal assays, several of these molecules, including serum amyloid P (SAP), PG D synthase, superoxide dismutase, renin, and total protease were validated to be elevated in the urine and kidneys of mice during anti-GBM disease, as well as in mice with spontaneously arising lupus nephritis. Among these, urinary protease was the only marker that appeared to be exclusively renal in origin, whereas the others were partly serum-derived. Longitudinal studies in murine lupus demonstrated that total urinary protease had better predictive value for histologically active nephritis (r = 0.78) compared with proteinuria (r = -0.04), azotemia (r = 0.28), or the other markers examined, whereas urine SAP emerged as the single most predictive marker of histological glomerulonephritis. Collectively, these studies uncover total urinary protease, PG D synthase, SAP, and superoxide dismutase as novel biomarkers of anti-GBM disease and lupus nephritis, with stronger correlation to renal disease compared with currently employed biomarkers. These findings could have important diagnostic and prognostic ramifications in the management of these renal diatheses.
Wu
Tianfu
T
Division of Rheumatology, Department of Internal Medicine, University of Texas Southwestern Medical School, Dallas, TX 75235, USA.
Fu
Yuyang
Y
Brekken
Deirdre
D
Yan
Mei
M
Zhou
Xin J
XJ
Vanarsa
Kamala
K
Deljavan
Nima
N
Ahn
Chul
C
Putterman
Chaim
C
Mohan
Chandra
C
D000595:Amino Acid Sequence; D000818:Animals; D019867:Anti-Glomerular Basement Membrane Disease / Q000201:enzymology / Q000276:immunology / Q000652:urine; D001323:Autoantibodies / Q000502:physiology; D015415:Biomarkers / Q000652:urine; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000276:immunology / Q000652:urine*; D007668:Kidney / Q000201:enzymology / Q000276:immunology / Q000473:pathology; D054834:Lipocalins / Q000276:immunology / Q000652:urine*; D008137:Longitudinal Studies; D008181:Lupus Nephritis / Q000201:enzymology* / Q000276:immunology / Q000652:urine*; D051379:Mice; D020297:Mice, Congenic; D008810:Mice, Inbred C57BL; D019463:Mice, Inbred MRL lpr; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000276:immunology / Q000652:urine*; D011237:Predictive Value of Tests; D020543:Proteome / Q000032:analysis* / Q000276:immunology; D000683:Serum Amyloid P-Component / Q000276:immunology / Q000652:urine*; D013482:Superoxide Dismutase / Q000276:immunology / Q000652:urine*; D015854:Up-Regulation / Q000276:immunology
D001323:Autoantibodies; D015415:Biomarkers; D054834:Lipocalins; D020543:Proteome; D000683:Serum Amyloid P-Component; D013482:Superoxide Dismutase; D010447:Peptide Hydrolases; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase