Investigate Pathogenic Role of Rheumatoid Arthritis, Sjogren's Syndrome, Systemic Lupus Erythematosus and Its Combined Syndromes from Post-Translational Modification of Novel Synovial Fluid and Serum Proteins---Study of 4-Hydroxy-2-Nonenal Modificatio

Primary Sjogren's syndrome (pSS), rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) are autoimmune diseases. Primary Sjogren's syndrome occurs by itself, and secondary Sjogren's syndrome (sSS) occurs with RA (RA-sSS) and SLE (SLE-sSS), and so on. Pathogenic roles caused from post-translational modification of antigens in autoimmune diseases include glycosylation, citrullination, proteolytic cleavage, ubiquitination, and oxidative modification. Reactive oxygen species produced from oxidative stress in autoimmune disease with inflammation status and caused lipid peroxidation by the depletion of unsaturated fatty acids of the cell membrane to generate 4-Hydroxy-2-nonenal (HNE), oxidtative modification, that is end-product of peroxidized w-6 polyunsaturated fatty acids. HNE can attack protein formed covalently-bonded adducts by reacting with lysine, histidine, cysteine and arginine residues. Autoantibodies against HNE-protein adducts show high immunogenicity in diseases including RA, SLE, cardiovascular diseases, alcoholic disease, chronic hepatitis C, and diabetes. In preliminary research, we found novel HNE-protein adducts in RA and autoantibody against HNE-BSA adducts in RA, pSS and SLE. In this study, we will investigate novel HNE-protein adducts and it's role in the pathogenesis of the RA, pSS, SLE and its combined syndromes. The study goals of year 1 include identification of novel HNE-protein adducts, preparation and validation of HNE-modified peptide, quantitative analysis of HNE-protein adducts and autoantibodies examination against HNE-modified peptides and HNE-protein adducts in synovial fluid and serum from healthy control, osteoarthritis (OA) and RA. The study goals of year 2 are identification of novel HNE-protein adducts, preparation and validation of HNE-modified peptide, quantitative analysis of HNE-protein adducts and autoantibodies examination against HNE-modified peptides and HNE-protein adducts in serum from healthy control, RA, pSS and RA-sSS. The study goals of year 3 are identification of novel HNE-protein adducts, preparation and validation of HNE-modified peptide, quantitative analysis of HNE-protein adducts and autoantibodies examination against HNE-modified peptides and HNE-protein adducts in serum from healthy control, pSS, SLE and SLE-sSS.