THU0234 INFLUENCE OF THE SPLICING MACHINERY DYSREGULATION ON THE PATHOGENESIS OF LUPUS AND THE KIDNEY INVOLVEMENT

Objectives: The aim of this study was to evaluate whether alterations in the splicing machinery of immune cells from Systemic Lupus Erythematosus (SLE) patients could influence the development and activity of the disease and the kidney involvement. Methods: The study was conducted in 41 SLE patients and 34 healthy donors (HD). Monocytes, lymphocytes and neutrophils were purified by immunomagnetic selection. Then, selected elements of the splicing machinery and a set of genes related to inflammation, renal and cardiovascular disease (including interleukins, adipocytokines, chemokines, and oxidative stress markers, among others) were evaluated using a microfluidic qPCR array (Fluidigm). Besides, the inflammatory profile in plasma, including the analysis of 27 proteins, was evaluated by using the Bioplex assay. In parallel, an extensive clinical/serological evaluation was performed; comprising disease activity and cardiovascular and renal involvement along with autoantibodies, complement factors, and acute phase reactants. Correlation and association studies and logistic models among those clinical and analytical parameters were developed. Mechanistic in vitro studies were carried out by incubation of HD-leukocytes with anti-dsDNA-IgG purified from SLE patients and changes promoted in both, splicing machinery and leukocyte inflammatory profile, were assessed. Results: A significantly altered expression of spliceosome components was found in all the leukocyte subsets: 27, 12 and 11 components were differentially expressed in monocytes, lymphocytes and neutrophils, respectively, in SLE patient’s vs HD. In parallel, a number of genes codifying for proteins involved in inflammation, fatty acid metabolism, oxidative stress and migration were found altered and correlations with spliceosome components were further identified. Besides, those statistical analyses demonstrated multiple links among altered spliceosome components and the clinical profile of these patients, such as the activity of the disease (SLEDAI), the occurrence of obstetric complications and the presence of arterial hypertension. Logistic regression and ROC curve analyses identified a signature composed in each leukocyte subset by 3 altered spliceosome components that could differentiate between SLE and HDs. Remarkably, the levels of a high number of those altered components were associated to the presence of lupus nephritis (LN). Moreover, ROC curve analyses allowed to identify several cell-specific spliceosome components as potential biomarkers of renal disease. In patients with LN we could also identify a distinctive inflammatory profile in plasma in relation to patients without renal involvement, which further correlated with the altered expression of a number of spliceosome components in each leukocyte subset. Lastly, the in vitro treatment of HD leukocytes with anti-dsDNA promoted the alteration of several spliceosome components found also altered in vivo in SLE lymphocytes, monocytes and neutrophils. Conclusion: 1)The splicing machinery is greatly altered in leukocytes from SLE patients, regulated, at least partially, by anti-dsDNA antibodies and closely related to the activity of the disease, including obstetrical complications, hypertension and lupus nephritis. 2)Specific components of the spliceosome in SLE leukocytes subsets might be used as potential biomarkers to typify the disease, particularly kidney involvement. Acknowledgments : Funded by ISCIII (PI18/00837 and RIER RD16/0012/0015) co-funded with FEDER. Disclosure of Interests: : Chary Lopez-Pedrera Grant/research support from: ROCHE and Pfizer., Maria Luque-Tevar: None declared, Alejandro Ibanez-Costa: None declared, Alejandra M. Patino-Trives: None declared, Maria A Aguirre: None declared, Perez Sanchez Laura: None declared, Maria del Carmen Abalos-Aguilera: None declared, Ivan Arias de la Rosa: None declared, Pedro Segui Azpilcueta: None declared, Mario Espinosa: None declared, Nuria Barbarroja Puerto Grant/research support from: ROCHE and Pfizer., Speakers bureau: ROCHE and Celgene., Eduardo Collantes-Estevez Grant/research support from: ROCHE and Pfizer., Speakers bureau: ROCHE, Lilly, Bristol and Celgene., Justo Pastor Castano Fuentes: None declared, Raul Miguel Luque Huertas: None declared, Carlos Perez-Sanchez: None declared