#3261 SAR131675, A SELECTIVE VEGFR3 INHIBITOR, AMELIORATES RENAL INFLAMMATION AND LYMPHANGIOGENESIS IN THE MURINE LUPUS NEPHRITIS MODEL

Abstract

Abstract Background and Aims Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by immune-complex deposits and inflammatory cell infiltrations in multiple organs, and approximately half of lupus patients have nephritis. Lymphangiogenesis is the proliferation of pre-existing lymphatic vessels (LVs), which regulate tissue fluid homeostasis and immune cell trafficking, responding to the tissue environment. In this study, we evaluated the therapeutic effect of SAR131672, a selective VEGFR3 inhibitor, on the murine lupus nephritis model by regulating inflammation and lymphangiogenesis. Method First, we reviewed medical records for the biopsy-proven lupus nephritis and performed an immunohistochemistry study for D2-40. For animal experiments, seven to eight-week-old male BALB/c mice were used. The back area's skin was shaved and treated topically three times per week, with 100 μg of resiquimod in 100 μl of acetone for eight weeks and concomitantly treatment of VEGFR3 inhibitor, SAR 131672 by oral gavage. We evaluated renal histology and immunofluorescent study for inflammatory cells and lymphatic vessels. We also evaluated inflammatory cytokines and chemokines, lymphangiogenic factors by qRT-PCR. Results In a human study, we found that the higher lupus activity index, the more D2-40(+) lymphatic vessels are expressed in the tubulointerstitial areas. In an animal study, eight weeks of topical treatment of resiquimod to Balb/c mice induces lupus-like symptoms such as weight loss, splenomegaly, and glomerular immune complexes deposits such as IgG, IgM, and C3 in immunofluorescent staining. Histologically, glomerular mesangial cell proliferation and increased inflammatory cells in tubulointerstitial areas were noted in the H&E stain. Inhibition of VEGFR3 by oral SAR131672 treatment decreases glomerular and tubulointerstitial inflammation and decreases LYVE-1(+) lymphatic vessels. The pro-inflammatory cytokines and chemokines such as ICAM-1, VCAM-1, MCP-1, CCL19, CCL21, CCR7, CXCL13, and BAFF mRNA levels were increased compared with the vehicle-treated group. Treatment SAR131672 decreases pro-inflammatory cytokines and chemokine. Conclusion Inhibition of VEGFR3 by SAR131672 decreases the resiquimod-induced lupus nephritis model by regulating inflammation and lymphangiogenesis.