Dawn J Caster1,2, Erik A Korte3, Michael L Merchant1, Jon B Klein1,2, Daniel W Wilkey1, Brad H Rovin4, Dan J Birmingham4, John B Harley5,6, Beth L Cobb5, Bahram Namjou5, Kenneth R McLeish1,2, David W Powell1,3. 1. Department of Medicine, University of Louisville School of Medicine, Louisville, KY, USA. 2. Robley Rex Veterans Affairs Medical Center, Louisville, KY, USA. 3. Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, KY, USA. 4. Department of Medicine, the Ohio State University, Columbus, OH, USA. 5. Center for Autoimmune Genomics and Etiology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center and the University of Cincinnati, Cincinnati, OH, USA. 6. US Department of Veterans Affairs Medical Center, Cincinnati, OH, USA.
Abstract
PURPOSE: Patients with systemic lupus erythematosus (SLE) frequently develop lupus nephritis (LN), a complication frequently leading to end stage kidney disease. Immune complex deposition in the glomerulus is central to the development of LN. Using a targeted proteomic approach, we tested the hypothesis that autoantibodies targeting glomerular antigens contribute to the development of LN. EXPERIMENTAL DESIGN: Human podocyte and glomerular proteins were separated by SDS-PAGE and immunoblotted with sera from SLE patients with and without LN. The regions of those gels corresponding to reactive bands observed with sera from LN patients were analyzed using LC-MS/MS. RESULTS: LN reactive bands were seen at approximately 50 kDa in podocyte extracts and between 36 and 50 kDa in glomerular extracts. Those bands were analyzed by LC-MS/MS and 102 overlapping proteins were identified. Bioinformatic analysis determined that 36 of those proteins were membrane associated, including a protein previously suggested to contribute to glomerulonephritis and LN, annexin A2. By ELISA, patients with proliferative LN demonstrated significantly increased antibodies against annexin A2. CONCLUSION AND CLINICAL RELEVANCE: Proteomic approaches identified multiple candidate antigens for autoantibodies in patients with LN. Serum antibodies against annexin A2 were significantly elevated in subjects with proliferative LN, validating those antibodies as potential biomarkers.
PURPOSE:Patients with systemic lupus erythematosus (SLE) frequently develop lupus nephritis (LN), a complication frequently leading to end stage kidney disease. Immune complex deposition in the glomerulus is central to the development of LN. Using a targeted proteomic approach, we tested the hypothesis that autoantibodies targeting glomerular antigens contribute to the development of LN. EXPERIMENTAL DESIGN:Human podocyte and glomerular proteins were separated by SDS-PAGE and immunoblotted with sera from SLEpatients with and without LN. The regions of those gels corresponding to reactive bands observed with sera from LN patients were analyzed using LC-MS/MS. RESULTS: LN reactive bands were seen at approximately 50 kDa in podocyte extracts and between 36 and 50 kDa in glomerular extracts. Those bands were analyzed by LC-MS/MS and 102 overlapping proteins were identified. Bioinformatic analysis determined that 36 of those proteins were membrane associated, including a protein previously suggested to contribute to glomerulonephritis and LN, annexin A2. By ELISA, patients with proliferative LN demonstrated significantly increased antibodies against annexin A2. CONCLUSION AND CLINICAL RELEVANCE: Proteomic approaches identified multiple candidate antigens for autoantibodies in patients with LN. Serum antibodies against annexin A2 were significantly elevated in subjects with proliferative LN, validating those antibodies as potential biomarkers.
Authors: Astrid Rasmussen; Sydney Sevier; Jennifer A Kelly; Stuart B Glenn; Teresa Aberle; Carisa M Cooney; Anya Grether; Ellen James; Jared Ning; Joanne Tesiram; Jean Morrisey; Tiny Powe; Mark Drexel; Wes Daniel; Bahram Namjou; Joshua O Ojwang; Kim L Nguyen; Joshua W Cavett; Jeannie L Te; Judith A James; R Hal Scofield; Kathy Moser; Gary S Gilkeson; Diane L Kamen; Craig W Carson; Ana I Quintero-del-Rio; Maria del Carmen Ballesteros; Marilynn G Punaro; David R Karp; Daniel J Wallace; Michael Weisman; Joan T Merrill; Roberto Rivera; Michelle A Petri; Daniel A Albert; Luis R Espinoza; Tammy O Utset; Timothy S Shaver; Eugene Arthur; Juan-Manuel Anaya; Gail R Bruner; John B Harley Journal: Rheumatology (Oxford) Date: 2010-09-23 Impact factor: 7.580
Authors: C Hugo; C Hugo; R Pichler; K Gordon; R Schmidt; M Amieva; W G Couser; H Furthmayr; R J Johnson Journal: J Clin Invest Date: 1996-06-01 Impact factor: 14.808
Authors: Heon Yung Gee; Pawaree Saisawat; Shazia Ashraf; Toby W Hurd; Virginia Vega-Warner; Humphrey Fang; Bodo B Beck; Olivier Gribouval; Weibin Zhou; Katrina A Diaz; Sivakumar Natarajan; Roger C Wiggins; Svjetlana Lovric; Gil Chernin; Dominik S Schoeb; Bugsu Ovunc; Yaacov Frishberg; Neveen A Soliman; Hanan M Fathy; Heike Goebel; Julia Hoefele; Lutz T Weber; Jeffrey W Innis; Christian Faul; Zhe Han; Joseph Washburn; Corinne Antignac; Shawn Levy; Edgar A Otto; Friedhelm Hildebrandt Journal: J Clin Invest Date: 2013-07-08 Impact factor: 14.808
Authors: Catherine Y Seiler; Jin G Park; Amit Sharma; Preston Hunter; Padmini Surapaneni; Casey Sedillo; James Field; Rhys Algar; Andrea Price; Jason Steel; Andrea Throop; Michael Fiacco; Joshua LaBaer Journal: Nucleic Acids Res Date: 2013-11-12 Impact factor: 16.971
Authors: Michael L Merchant; Michael E Brier; Mark S Slaughter; Jon B Klein; Kenneth R McLeish Journal: BMC Nephrol Date: 2018-05-02 Impact factor: 2.388