0000000000255846
AUTHOR
Vicki Rubin Kelley
TD-09 IL-34 promotes macrophage-mediated lupus nephritis in MRL-Faslpr mice
Background Nephritis is the major cause of mortality and morbidity in patients with lupus. Macrophages (Mo) are central to kidney destruction in lupus-prone mice and patients. CSF-1, and the newly identified IL-34, mediate Mo survival and proliferation. However, IL-34 and CSF-1 differ during development and disease. While CSF-1 and IL-34 share the CSF-1 receptor (cFMS), expressed by Mo, IL-34 binds to a second receptor, Protein-Tyrosine Phosphatase ζ (PTPRZ) in inflamed kidneys. Intra-renal IL-34, cFMS, and PTPRZ are increased during the progression of lupus nephritis in MRL-Faslpr mice. Therefore, we hypothesized that IL-34 is a potential therapeutic target for lupus nephritis. Methods and…
Correlation of renal tubular epithelial cell-derived interleukin-18 up-regulation with disease activity in MRL-Faslpr mice with autoimmune lupus nephritis.
Objective MRL-Faslpr mice spontaneously develop an autoimmune disease that mimics systemic lupus erythematosus in humans. Infiltrating T cells expressing interferon-γ (IFNγ) are responsible for the autoimmune kidney destruction in MRL-Faslpr mice, and interleukin-18 (IL-18) released by mononuclear phagocytes stimulates T cells to produce the IFNγ. Since MRL-Faslpr T cells are characterized by an overexpression of the IL-18 receptor accessory chain, we sought to determine the impact of IL-18 on the progression of lupus nephritis in MRL-Faslpr mice. Methods IL-18 expression in sera and kidney tissues from MRL-Faslpr mice was determined by enzyme-linked immunosorbent assay (ELISA), reverse tra…
IL-34–Dependent Intrarenal and Systemic Mechanisms Promote Lupus Nephritis in MRL-Faslpr Mice
Background In people with SLE and in the MRL- Fas lpr lupus mouse model, macrophages and autoantibodies are central to lupus nephritis. IL-34 mediates macrophage survival and proliferation, is expressed by tubular epithelial cells (TECs), and binds to the cFMS receptor on macrophages and to a newly identified second receptor, PTPRZ. Methods To investigate whether IL-34–dependent intrarenal and systemic mechanisms promote lupus nephritis, we compared lupus nephritis and systemic illness in MRL- Fas lpr mice expressing IL-34 and IL-34 knockout (KO) MRL- Fas lpr mice. We also assessed expression of IL-34 and the cFMS and PTPRZ receptors in patients with lupus nephritis. Results Intrarenal IL-3…
CSF-1 signals directly to renal tubular epithelial cells to mediate repair in mice
金沢大学医薬保健研究域医学系
Inducible Co-Stimulator Null MRL-Fas lpr Mice
MRL/MpJ-Tnfrsf6lpr (MRL-Faslpr) mice develop a spontaneous T cell-dependent autoimmune disease that shares features with human lupus, including fatal nephritis, systemic pathology, and autoantibodies (autoAb). The inducible co-stimulator (ICOS) is upregulated on activated T cells and modulates T cell-mediated responses. To investigate whether ICOS has an essential role in regulating autoimmune lupus nephritis and the systemic illness in MRL-Faslpr mice, ICOS null (-/-) MRL Faslpr and ICOS intact (+/+) MRL-Faslpr strains (wild-type [WT]) were generated and compared. It was determined that in ICOS-/- MRL-Faslpr as compared with the WT strain, (1) there is a significant reduction in circulatin…
Circulating CSF-1 Promotes Monocyte and Macrophage Phenotypes that Enhance Lupus Nephritis
Macrophages mediate kidney disease and are prominent in a mouse model (MRL- Fas lpr ) of lupus nephritis. Colony stimulating factor-1 (CSF-1) is the primary growth factor for macrophages, and CSF-1 deficiency protects MRL- Fas lpr mice from kidney disease and systemic illness. Whether this renoprotection derives from a reduction of macrophages and whether systemic CSF-1, as opposed to intrarenal CSF-1, promotes macrophage-dependent lupus nephritis remain unclear. Here, we found that increasing systemic CSF-1 hastened the onset of lupus nephritis in MRL- Fas lpr mice. Using mutant MRL- Fas lpr strains that express high, moderate, or no systemic CSF-1, we detected a much higher tempo of kidne…
Targeting transcription factor Stat4 uncovers a role for interleukin-18 in the pathogenesis of severe lupus nephritis in mice
Polymorphisms in the transcription factor Stat4 gene have been implicated as risk factors for systemic lupus erythematosus. Although some polymorphisms have a strong association with autoantibodies and nephritis, their impact on pathophysiology is still unknown. To explore this further we used signal transducers and activators of transcription 4 (Stat4) knockout MRL/MpJ-Fas(lpr)/Fas(lpr) (MRL-Fas(lpr)) mice and found that they did not differ in survival or renal function from Stat4-intact MRL-Fas(lpr) mice. Circulating interleukin (IL)-18 levels, however, were elevated in Stat4-deficient compared to Stat4-intact mice, suggesting that this interleukin might contribute to the progression of l…
Interferon-beta: a therapeutic for autoimmune lupus in MRL-Faslpr mice.
Type I interferons are associated with lupus. Genes that are regulated by IFN-alpha are upregulated in pediatric lupus patients. Gene deletion of the IFN-alpha/beta receptor in experimental lupus-like NZB mice results in reduced disease activity. Conversely, IFN-beta is a well-established treatment in multiple sclerosis, another autoimmune disease. For determining whether IFN-beta treatment is harmful or beneficial in lupus, MRL-Fas(lpr) mice were injected with this type I IFN. Treatment was initiated in MRL-Fas(lpr) mice with mild and advanced disease. IFN-beta was highly effective in prolonging survival and ameliorating the clinical (renal function, proteinuria, splenomegaly, and skin les…
PS7:145 Il-34, not csf-1, similarly mediates rheumatoid and lupus arthritis in patients
While Myeloid cells are abundant in lupus arthritis (LA) and rheumatoid arthritis (RA), based on clinical presentation LA and RA are considered distinct diseases. Although inflammatory arthritis is common in patients with lupus, the pivotal mechanisms leading to joint damage have not been investigated. We tested the hypothesis that IL-34, but not CSF-1, is a predictive biomarker that is integral in perpetuating synovial destructive inflammation in both LA and RA. We report the novel findings that: using longitudinally tracked patients, IL–34, not CSF–1, is a clinical predictive biomarker for both LA and RA; and IL–34 is more robustly expressed in the synovial tissue, cells and fluid compare…
Colony-Stimulating Factor-1
A noninvasive means to predict the onset and recurrence of lupus nephritis (LN) before overt renal injury is needed to optimize and individualize treatment. Colony-stimulating factor-1 (CSF-1) is expressed by kidney tubules at the onset of LN, increases with disease progression, and spills into the circulation in lupus-prone mice. We tested the hypothesis that amplified expression of CSF-1 detected in the serum or urine correlates with intrarenal CSF-1 expression and histopathology (increased macrophage accumulation, activity indices) and clinical kidney disease activity and predicts the onset and recurrence of nephritis in patients with systemic lupus erythematosus (SLE). We found increase…