title: Decreased expression of the Ets family transcription factor Fli-1 markedly prolongs survival and significantly reduces renal disease in MRL/lpr mice.
abstract: Increased Fli-1 mRNA is present in PBLs from systemic lupus erythematosus patients, and transgenic overexpression of Fli-1 in normal mice leads to a lupus-like disease. We report in this study that MRL/lpr mice, an animal model of systemic lupus erythematosus, have increased splenic expression of Fli-1 protein compared with BALB/c mice. Using mice with targeted gene disruption, we examined the effect of reduced Fli-1 expression on disease development in MRL/lpr mice. Complete knockout of Fli-1 is lethal in utero. Fli-1 protein expression in heterozygous MRL/lpr (Fli-1(+/-)) mice was reduced by 50% compared with wild-type MRL/lpr (Fli-1(+/+)) mice. Fli-1(+/-) MRL/lpr mice had significantly decreased serum levels of total IgG and anti-dsDNA Abs as disease progressed. Fli-1(+/-) MRL/lpr mice had significantly increased splenic CD8(+) and naive T cells compared with Fli-1(+/+) MRL/lpr mice. Both in vivo and in vitro production of MCP-1 were significantly decreased in Fli-1(+/-) MRL/lpr mice. The Fli-1(+/-) mice had markedly decreased proteinuria and significantly lower pathologic renal scores. At 48 wk of age, survival was significantly increased in the Fli-1(+/-) MRL/lpr mice, as 100% of Fli-1(+/-) MRL/lpr mice were alive, in contrast to only 27% of Fli-1(+/+) mice. These findings indicate that Fli-1 expression is important in lupus-like disease development, and that modulation of Fli-1 expression profoundly decreases renal disease and improves survival in MRL/lpr mice.
authors.affiliation: Department of Medicine, Division of Rheumatology and Immunology, Medical Research Service, Ralph H. Johnson Veterans Affairs Medical Center, Medical University of South Carolina, 96 Jonathan Lucas Street, Charleston, SC 29425, USA. zhangjo@musc.edu
authors.forename: Xian K
authors.initials: XK
authors.lastname: Zhang
authors.forename: Sarah
authors.initials: S
authors.lastname: Gallant
authors.forename: Ivan
authors.initials: I
authors.lastname: Molano
authors.forename: Omar M
authors.initials: OM
authors.lastname: Moussa
authors.forename: Phillip
authors.initials: P
authors.lastname: Ruiz
authors.forename: Demetri D
authors.initials: DD
authors.lastname: Spyropoulos
authors.forename: Dennis K
authors.initials: DK
authors.lastname: Watson
authors.forename: Gary
authors.initials: G
authors.lastname: Gilkeson
mesh_terms: D000818:Animals; D001323:Autoantibodies / Q000096:biosynthesis; D018925:Chemokines / Q000096:biosynthesis / Q000097:blood; D016207:Cytokines / Q000096:biosynthesis / Q000097:blood; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis* / Q000172:deficiency / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics / Q000276:immunology; D005434:Flow Cytometry; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000097:blood; D008180:Lupus Erythematosus, Systemic / Q000235:genetics / Q000401:mortality* / Q000473:pathology / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D019463:Mice, Inbred MRL lpr; D010641:Phenotype; D011507:Proteinuria / Q000235:genetics / Q000517:prevention & control; D051789:Proto-Oncogene Protein c-fli-1; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis* / Q000172:deficiency / Q000235:genetics; D050783:Proto-Oncogene Proteins c-ets; D013154:Spleen / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D015996:Survival Rate; D013997:Time Factors; D015534:Trans-Activators / Q000037:antagonists & inhibitors* / Q000096:biosynthesis* / Q000172:deficiency / Q000235:genetics; D014157:Transcription Factors / Q000037:antagonists & inhibitors* / Q000096:biosynthesis*; D015854:Up-Regulation / Q000276:immunology
chemical_list: D001323:Autoantibodies; D018925:Chemokines; D016207:Cytokines; D004268:DNA-Binding Proteins; C497426:Fli1 protein, mouse; D007074:Immunoglobulin G; D051789:Proto-Oncogene Protein c-fli-1; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D015534:Trans-Activators; D014157:Transcription Factors