Johnson VA Medical Center, Charleston, SC. Ahmad K. electrochemical detection for markers of SO production (durable modifications of serum protein Tyr ultimately requiring SO as a substrate). Renal cortex from MRL/MpJ-(MRL/lpr) mice with and without functional eNOS was analyzed during active disease for superoxide (SO) production with and without inhibitors of SO generating enzymes. Results Serum protein modifications indicative of total SO production were significantly higher in patients with PLN. These markers were increased in association with more active, inflammatory PLN. Mice lacking functional eNOS experienced 80% higher levels of renal cortical SO during active disease, and inhibitors of Rabbit polyclonal to ABHD14B nitric KW-2449 oxide synthase and NADPH oxidase reduced these levels by 60% and 77%, respectively. Conclusion These studies demonstrate that SO production is unique to active PLN in a NOS and NADPH oxidase-dependent fashion. These findings suggest the emulating or augmenting eNOS activity or inhibiting NADPH oxidase SO production may be targets of therapy in patients with PLN. The KW-2449 markers of SO production used in this study could rationally be used to select SO-modulating therapies and serve as pharmacodynamic indicators for dose titration. (MRL/lpr) mice with and without functional endothelial nitric oxide synthase (eNOS) was analyzed during active disease for superoxide production with and without inhibitors of superoxide generating enzymes. Serum markers of superoxide production were significantly higher in patients with PLN. Mice lacking functional eNOS experienced 80% higher levels of renal cortical superoxide during active disease, and inhibitors of NADPH oxidase and nitric oxide synthase (NOS) reduced these levels by 76% and 61% respectively. These studies offer the rationale for targeted therapies designed to emulate or activate eNOS activity or inhibit NADPH oxidase-mediated superoxide production in PLN. Acknowledgments This work was supported by the Arthritis Foundation, Atlanta, GA, the University or college Research Committee at the Medical University or college of SC, the Medical University or college of SC General Clinical Research Center [NIH grant number MO1RR001070], the Medical University or college of SC Clinical and Translational Science Award [grant number UL1TR000062, formerly U54RR026107], the Division of Rheumatology and Immunology Multidisciplinary Clinical Research Center [grant number P60AR062755], and National Institutes of Health [grant figures K08AR002193, AI047469, AR045476, and AR04745], the Ralph H. Johnson VAMC Medical KW-2449 Research KW-2449 Service, and the Department of Veterans Affairs Career Development, Research Enhancement Awards. Special thanks go to the patients who participated in this study. This project would not have been possible without coordination from Lori Ueberroth, Stephanie Slan, Tia Parker and technical support from Thomas Fleury, Jon Donohue, and Ann Hofbauer. Sally E Self, MD deserves special acknowledgement for performing the classification of renal biopsies. Footnotes Discord of Interest Statement The authors declare no discord of interest. None of the potential conflicts of interest (commercial or nonprofit) are relevant to this work. No commercial or noncommercial products Contributor Information Jim C. Oates, Department of Medicine, Division of Rheumatology, Medical University or college of South Carolina, Charleston, SC and Medical Service, Ralph H. Johnson VA Medical Center, Charleston, SC. Ahmad K. Mashmoushi, Department of Medicine, Division of Rheumatology, Medical University or college of South Carolina, Charleston, SC. Stephanie R. Shaftman, Department of Biostatistics, Bioinformatics & Epidemiology, Medical KW-2449 University or college of South Carolina, Charleston, SC. Gary S. Gilkeson, Department of Medicine, Division of Rheumatology, Medical University or college of South Carolina, Charleston, SC and Medical Support, Ralph H. Johnson VA Medical Center, Charleston, SC..