A recent metabolomic screen of sera from patients with Systemic Lupus Erythematosus (SLE) found reduction of antioxidants and substrates for energy generation. These metabolic alterations may underlie one of the most common features of SLE - fatigue. The metabolomic studies also noted reduced omega-3 fatty acids, which are powerful anti- oxidants. This deficiency may be causally related to oxidative stress, inflammation, disease activity, and fatigue in SLE. Supplementation of omega-3 fatty acids using fish oil in SLE has been shown to reduce oxidative stress in other studies. The objective of this study is to evaluate the effect of fish oil supplementation on clinical measures of fatigue, quality of life, and disease activity as part of a randomized clinical trial. Fifty SLE patients recruited in outpatient clinics were randomized 1:1 to fish oil supplementation or olive oil placebo, and blinded to their treatment group. At baseline and after 6 months of treatment, RAND Short Form-36 (RAND SF-36), Fatigue Severity Scale (FSS), SLE Disease Activity Index (SLEDAI), and Physician Global Assessment (PGA) were completed; serum was also collected for soluble mediator analysis. Thirty-two patients completed the study. PGA improved significantly in the fish oil group compared with the placebo group (p = 0.015). The RAND SF-36 Energy/fatigue and Emotional well-being scores demonstrated improvement trends (p = 0.092 and 0.070). No clear difference was seen in FSS and SLEDAI (p = 0.350 and p = 0.417). Erythrocyte sedimentation rate and serum IL-12 were reduced (p = 0.008 and p = 0.058); while serum IL-13 was increased by fish oil supplementation (p = 0.033). In this randomized, placebo-controlled 6-month trial, SLE patients randomized to fish oil supplementation demonstrated improvement in their PGA, RAND SF-36, and some circulating inflammatory markers. ClinicalTrials.gov Identifier: NCT02021513 (registered 13 December 2013).

This article reviews the commonly used murine strains for studying lupus and lupus nephritis, including strains that develop lupus spontaneously, congenic strains, induced models of lupus, as well as genetically engineered mouse models of lupus bearing transgenes or knockouts. The review then summarizes the main cellular and molecular pathways that lead to the pathogenesis of this autoimmune disease, including autoantibodies. Finally, it concludes with therapeutic insights gained from using mouse models of lupus. To sum, much of what we have learned about lupus has arisen from studying mouse models of the disease, and the laboratory mouse continues to be one of the best tools for studying human SLE.

Previously we have shown that kallikreins (klks) play a renoprotective role in nephrotoxic serum induced nephritis. In this study, we have used mesenchymal stem cells (MSCs) as vehicles to deliver klks into the injured kidneys and have measured their therapeutic effect on experimental antibody induced nephritis and lupus nephritis. Human KLK-1 (hKLK1) gene was transduced into murine MSCs using a retroviral vector to generate a stable cell line, hKLK1-MSC, expressing high levels of hKLK1. 129/svj mice subjected to anti-GBM induced nephritis were transplanted with 10⁶ hKLK1-MSCs and hKLK1 expression was confirmed in the kidneys. Compared with vector-MSCs injected mice, the hKLK1-MSCs treated mice showed significantly reduced proteinuria, blood urea nitrogen (BUN) and ameliorated renal pathology. Using the same strategy, we treated lupus-prone B6.Sle1.Sle3 bicongenic mice with hKLK1-MSCs and demonstrated that hKLK1-MSCs delivery also attenuated lupus nephritis. Mechanistically, hKLK1-MSCs reduced macrophage and T-lymphocyte infiltration into the kidney by suppressing the expression of inflammation cytokines. Moreover, hKLK1 transduced MSCs were more resistant to oxidative stress-induced apoptosis. These findings advance genetically modified MSCs as potential gene delivery tools for targeting therapeutic agents to the kidneys in order to modulate inflammation and oxidative stress in lupus nephritis.

C57BL/6 mice bearing the Sle2^z lupus-susceptibility congenic interval on chromosome 4 display high titers of polyclonal autoantibodies with generalized B cell hyperactivity, hallmarks of systemic lupus erythematosus. In B6.Sle2^zHEL^Ig.sHEL BCR-transgenic mice, Sle2^z did not breach central tolerance, but it led to heightened expression of endogenous Ig H and L chains in splenic B cells, upregulation of RAG, and serological polyreactivity, suggestive of excessive receptor revision. Fatty acid amide hydrolase (FAAH), a gene in the minimal subcongenic interval generated through recombinant mapping, was found to be upregulated in Sle2^z B cells by microarray analysis, Western blot, and functional assays. Pharmacological inhibition of FAAH reversed the increase in receptor revision, RAG expression, and polyreactive autoantibodies in lupus-prone mice. These studies indicate that increased peripheral BCR revision, or selective peripheral expansion of BCR-revised B cells, may lead to systemic autoimmunity and that FAAH is a lupus-susceptibility gene that might regulate this process.