Systemic Lupus Erythematosus Mice Research Articles

The Oxysterol Receptor EBI2 Links Innate and Adaptive Immunity to Limit IFN Response and Systemic Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with abnormal activation of the immune system. Recent attention is increasing about how aberrant lipid and cholesterol metabolism is linked together with type I interferon (IFN-I) signaling in the regulation of the pathogenesis of SLE. Here, a metabonomic analysis is performed and increased plasma concentrations of oxysterols, especially 7α, 25-dihydroxycholesterol (7α, 25-OHC), are identified in SLE patients. The authors find that 7α, 25-OHC binding to its receptor Epstein-Barr virus-induced gene 2 (EBI2) in macrophages can suppress STAT activation and the production of IFN-β, chemokines, and cytokines. Importantly, monocytes/macrophages from SLE patients and mice show significantly reduced EBI2expression, which can be triggered by IFN-γ produced in activated T cells. Previous findings suggest that EBI2enhances immune cell migration. Opposite to this effect, the authors demonstrate that EBI2-deficient macrophages produce higher levels of chemokines and cytokines, which recruits and activates myeloid cells,T and B lymphocytes to exacerbate tetramethylpentadecane-induced SLE. Together, via sensing the oxysterol 7α, 25-OHC, EBI2in macrophages can modulate innate and adaptive immune responses, which may be used as a potential diagnostic marker and therapeutic target for SLE.

Deficient AMPK activity contributes to hyperexcitability in peripheral nociceptive sensory neurons and thermal hyperalgesia in lupus mice.

Patients with systemic lupus erythematosus (SLE) often suffer from chronic pain. Little is known about the peripheral mechanisms underlying the genesis of chronic pain induced by SLE. The aim of this study was to investigate whether and how membrane properties in nociceptive neurons in the dorsal root ganglions (DRGs) are altered by SLE. We found elevation of resting membrane potentials, smaller capacitances, lower action potential thresholds and rheobases in nociceptive neurons in the DRGs from MRL/lpr mice (an SLE mouse model) with thermal hyperalgesia. DRGs from MRL/lpr mice had increased protein expressions in TNFα, IL-1β, and phosphorylated ERK but suppressed AMPK activity, and no changes in sodium channel 1.7 protein expression. We showed that intraplantar injection of Compound C (an AMPK inhibitor) induced thermal hyperalgesia in normal mice while intraplantar injection of AICAR (an AMPK activator) reduced thermal hyperalgesia in MRL/Lpr mice. Upon inhibition of AMPK membrane properties in nociceptive neurons from normal control mice could be rapidly switched to those found in SLE mice with thermal hyperalgesia. Our study indicates that increased excitability in peripheral nociceptive sensory neurons contributes to the genesis of thermal hyperalgesia in mice with SLE, and AMPK regulates membrane properties in nociceptive sensory neurons as well as thermal hyperalgesia in mice with SLE. Our study provides a basis for targeting signaling pathways regulating membrane properties of peripheral nociceptive neurons as a means for conquering chronic pain caused by SLE.

Akkermansia muciniphila and Lactobacillus plantarum ameliorate systemic lupus erythematosus by possibly regulating immune response and remodeling gut microbiota.

Systemic lupus erythematosus (SLE), characterized by persistent inflammation, is a complex autoimmune disorder that affects all organs, challenging clinical treatment. Dysbiosis of gut microbiota promotes autoimmune disorders that damage extraintestinal organs. Modulating the gut microbiome is proposed as a promising approach for fine-running parts of the immune system, relieving systematic inflammation in multiple diseases. This study demonstrated that the administration of Akkermansia muciniphila and Lactobacillus plantarum contributed to an anti-inflammatory environment by decreasing IL-6 and IL-17 and increasing IL-10 levels in the circulation. The treatment of A. muciniphila and L. plantarum restored the intestinal barrier integrity to a different extent. In addition, both strains reduced the deposit of IgG in the kidney and improved renal function significantly. Further studies revealed distinct remodeling roles of A. muciniphila and L. plantarum administration on the gut microbiome. This work demonstrated essential mechanisms of how A. muciniphila and L. plantarum remodel gut microbiota and regulate the immune responses in the SLE mice model. IMPORTANCE Several pieces of research have demonstrated that certain probiotic strains contribute to regulating excessive inflammation and restoring tolerances in the SLE animal model. More animal trials combined with clinical studies are urgently needed to further elucidate the mechanisms for the effect of specific probiotic bacteria in preventing SLE symptoms and developing novel therapeutic targets. In this study, we explored the role of A. muciniphila and L. plantarum in ameliorating the SLE disease activity. Both A. muciniphila and L. plantarum treatment relieved the systemic inflammation and improved renal function in the SLE mouse model. We demonstrated that A. muciniphila and L. plantarum contributed to an anti-inflammatory environment by regulating cytokine levels in the circulation, restoring the intestinal barrier integrity, and remodeling the gut microbiome, however, to a different extent.

Disturbance of neuron–microglia crosstalk mediated by GRP78 in Neuropsychiatric systemic lupus erythematosus mice

ObjectivesNeuropsychiatric systemic lupus erythematosus (NPSLE) is a serious phenotype of systemic lupus erythematosus (SLE). The disturbance of neuron–microglia crosstalk is recently revealed in many neuropsychiatric diseases but was not well studied in NPSLE. We found glucose regulatory protein 78 (GRP78), a marker of endoplasmic reticulum stress, was significantly increased in the cerebrospinal fluid (CSF) of our NPSLE cohort. We, therefore, investigated whether GRP78 can act as a mediator between the neuron–microglia crosstalk and is involved in the pathogenic process of NPSLE.MethodsSerum and CSF parameters were analyzed in 22 NPSLE patients and controls. Anti-DWEYS IgG was injected intravenously into mice to establish a model of NPSLE. Behavioral assessment, histopathological staining, RNA-seq analyses, and biochemical assays were performed to examine the neuro-immunological alterations in the mice. Rapamycin was intraperitoneally administered to define the therapeutic effect.ResultsThe level of GRP78 was elevated significantly in the CSF of the patients with NPSLE. An increase in GRP78 expression, accompanied by neuroinflammation and cognitive impairment, was also found in the brain tissues of the NPSLE model mice induced by anti-DWEYS IgG deposition on hippocampal neurons. In vitro experiments demonstrated that anti-DWEYS IgG could stimulate neurons to release GRP78, which activated microglia via TLR4/MyD88/NFκB pathway to produce more pro-inflammatory cytokines and promote migration and phagocytosis. Rapamycin ameliorated GRP78-inducing neuroinflammation and cognitive impairment in anti-DWEYS IgG-transferred mice.ConclusionGRP78 acts as a pathogenic factor in neuropsychiatric disorders via interfering neuron–microglia crosstalk. Rapamycin may be a promising therapeutic candidate for NPSLE.

Pathogenicity ofIgG-Fc desialylation andits association with Th17 cells inan animal model ofsystemic lupus erythematosus.

Decreased sialylation of IgG-Fc glycans has been reported in autoimmune diseases, but its role in systemic lupus erythematosus (SLE) is not fully understood. In this study, we examined the pathogenicity of IgG desialylation and its association with Th17 in SLE using an animal model. B6SKG mice, which develop lupus-like systemic autoimmunity due to the ZAP70 mutation, were used to investigate the pathogenicity of IgG desialylation. The proportion of sialylated IgG was compared between B6SKG and wild-type mice with or without β-glucan treatment-induced Th17 expansion. Anti-interleukin (IL)-23 and anti-IL-17 antibodies were used to examine the role of Th17 cells in IgG glycosylation. Activation-induced cytidine deaminase-specific St6gal1 conditionally knockout (cKO) mice were generated to examine the direct effect of IgG desialylation. The proportions of sialylated IgG were similar between B6SKG and wild-type mice in the steady state. However, IgG desialylation was observed after β-glucan-induced Th17 expansion, and nephropathy also worsened in B6SKG mice. Anti-IL-23/17 treatment suppressed IgG desialylation and nephropathy. Glomerular atrophy was observed in the cKO mice, suggesting that IgG desialylation is directly involved in disease exacerbation. IgG desialylation contributes to the progression of nephropathy, which is ameliorated by blocking IL-17A or IL-23 in an SLE mouse model.

A quinazoline derivative suppresses B cell hyper-activation and ameliorates the severity of systemic lupus erythematosus in mice.

Background: Aberrant autoreactive B cell responses contribute to the pathogenesis of systemic lupus erythematosus (SLE). Currently, there is no safe and effective drug for intervention of SLE. Quinazoline derivative (N4-(4-phenoxyphenethyl)quinazoline-4,6-diamine, QNZ) is a NF-κB inhibitor and has potent anti-inflammatory activity. However, it is unclear whether QNZ treatment can modulate B cell activation and SLE severity. Methods: Splenic CD19+ B cells were treated with QNZ (2, 10, or 50nM) or paeoniflorin (200μM, a positive control), and their activation and antigen presentation function-related molecule expression were examined by flow cytometry. MRL/lpr lupus-prone mice were randomized and treated intraperitoneally with vehicle alone, 0.2mg/kg/d QNZ or 1mg/kg/d FK-506 (tacrolimus, a positive control) for 8weeks. Their body weights and clinical symptoms were measured and the frequency of different subsets of splenic and lymph node activated B cells were quantified by flow cytometry. The degrees of kidney inflammation and glycogen deposition were examined by hematoxylin and eosin (H&E) and PAS staining. The levels of serum autoantibodies and renal IgG, complement C3 deposition were examined by ELISA and immunofluorescence. Results: QNZ treatment significantly inhibited the activation and antigen presentation-related molecule expression of B cells in vitro. Similarly, treatment with QNZ significantly mitigated the SLE activity by reducing the frequency of activated B cells and plasma cells in MRL/lpr mice. Conclusion: QNZ treatment ameliorated the severity of SLE in MRL/lpr mice, which may be associated with inhibiting B cell activation, and plasma cell formation. QNZ may be an excellent candidate for the treatment of SLE and other autoimmune diseases.

Effect of Sigma-1 Receptor Activation on Renal Injury and Hypertension in Female Mice with Lupus

Systemic lupus erythematosus (SLE) is a female dominant autoimmune disease that presents with prominent renal injury and hypertension contributing to the morbidity and mortality. While the causality and association of the renal injury and hypertension is not completely understood, novel therapies to reduce these detrimental outcomes could be beneficial to SLE patients. The sigma-1 receptor is a cytoprotective ligand-regulated chaperone protein that acts by decreasing protein aggregation, cellular stress and cell death, thus preventing tissue injury. Activation of the sigma-1 receptor with pharmacological ligands enhances cytoprotection in autoimmune diseases like multiple sclerosis and Huntington’s disease; however, the efficacy of sigma-1 receptor agonists in SLE is not known. We hypothesize that sigma-1 receptor activation with the agonist, LS-1-127, will reduce renal injury and halt the progression of hypertension in SLE mice.Female SLE ( NZBWF1) mice and control ( NZW) mice were weighed and urine collected via metabolic cages weekly starting at 30 weeks of age. Urinary albumin was measured via dipsticks. At 33 weeks of age, SLE and control mice were treated with the sigma-1 receptor ligand (LS-1-127; 10 mg/kg IP) or equal volume of vehicle (10% DMSO; IP) three times a week for two weeks. At 35 weeks, mean arterial pressure (MAP) was measured in conscious mice using indwelling carotid catheters for two consecutive days and then mice were euthanized. Markers of renal injury, including urinary neutrophil gelatinase associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and creatinine were measured by ELISA.Body weight (g) was not different in SLE vs. control mice (39.2 ± 2.9 vs. 35.4 ± 0.9; p=0.44) and LS-1-127 did not alter body weight in SLE mice (39.1 ± 2.2; p=0.97) or controls (34.1 ± 0.6; p=0.84). Albuminuria was present in 44.4% (4 out of 9) of SLE/Veh mice and none of the controls. LS-1-127 did not improve albuminuria in SLE mice (50%; 3 out of 6). MAP (mmHg) was higher in SLE mice compared to control mice (146 ± 4 vs. 123 ± 3; n=9-10, p <0.0001). LS-1-127 did not significantly alter MAP in SLE mice (150± 8; n=6) or controls (124 ± 2; n=10). The NGAL-to-creatinine ratio (ng/mg) was higher in the SLE mice compared to controls (327.3±119.8 vs 63.2±4.3, n=9-12, p<0.0007). LS-1-127 treatment did not significantly alter the NGAL-to-creatinine ratio in SLE mice (484.3±209.0, n= 6) or control mice (71.7 ± 5.2, n=10). The KIM1-to-creatinine ratio (ng/mg) was not significantly different between any of the groups.In conclusion, two weeks of sigma-1 receptor activation with LS-1-127 did not significantly alter blood pressure or renal injury in female SLE mice with advanced disease. Further inquiry into the effect of LS-1-127 on the expression of various cellular stress markers in the kidney will be conducted. Also sigma-1 receptor activation at different stages of SLE disease progression warrants investigation. NIH (R01HL153703, K01HL139859) and Department of Defense (LR210096) This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Fecal microbiota transplantation attenuates hypertension in a female mouse model of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a prototypic multisystem autoimmune disorder that disproportionately affects women. SLE is characterized by a breach of immunological self-tolerance and the expansion of autoreactive T and B lymphocytes, leading to the production of autoantibodies. Autoantibody production leads to downstream chronic inflammation resulting in high rates of hypertension, renal injury, and cardiovascular disease. Alterations in the gut microbiota, or gut dysbiosis, is associated with many autoimmune diseases, including SLE. In the present study, we hypothesized that gut dysbiosis in SLE may play a role in the development of immune system dysfunction and hypertension in an experimental model of SLE, and that fecal microbiota transplantation (FMT) with microbes from control mice may improve these parameters. To test this hypothesis, we treated 26-week-old female control (NZW, n=19) and SLE (NZBWF1, n=19) mice with broad spectrum antibiotics (0.4 g/L ampicillin, 0.4 g/L neomycin sulfate, 0.4 g/L metronidazole, and 0.2 g/L vancomycin) in drinking water for one week to deplete the existing microbiota. Subsequently, mice were given 0.1 mL of fecal microbes via oral gavage two times per week for four weeks in the following groups (n=9-10 mice/group): Control-vehicle, Control-SLE microbes, SLE-vehicle, SLE-Control microbes. Changes in the gut microbiome before and after FMT were assessed by 16S rRNA analysis of the microbiome. Mean arterial pressure (MAP, mmHg), measured in conscious mice by carotid artery catheter was higher in SLE mice that received SLE microbes (Control: 112±3 vs. SLE: 140 ±2 mmHg, p<0.0001). SLE mice that received FMT with control microbes had lower blood pressure (SLE-Control microbes: 126±4 mmHg, p=0.03). Renal injury, as assessed by urinary albumin excretion at the conclusion of the study, was not significantly different among the groups (p=0.3523). Circulating autoantibodies and immunoglobulins were also measured at the conclusion of the study. Anti-dsDNA IgG was elevated in SLE mice compared to control (Control: 149±38 vs. SLE: 527±114 kU/mL, p=0.02), and were significantly lower in SLE mice treated with control microbes (SLE-Control microbes: 126±4 mmHg, p=0.03). Circulating IgM was also elevated in SLE mice (Control: 0.053±0.008 vs. SLE: 0.32±0.04 mg/mL, p<0.0001), and FMT lowered IgM in SLE mice that received FMT (0.19±0.03 mg/mL, p=0.0069). These data suggest that gut microbiota present in NZBWF1 mice contribute to both autoantibody production and the development of hypertension, and that interventions to alter the microbiora could have a beneficial impact on disease activity in SLE patients. NIH NIGMS P20GM104357 to UMMC Department of Physiology and Biophysics, NIH NHLBI R00HL146888 to Erin Taylor This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Early life stress (ELS) promotes B cell expansion and aortic pathology in a mouse model of systemic lupus erythematosus (SLE)

SLE is an autoimmune disease that primarily affects young women and is associated with high rates of cardiovascular disease (CVD). Exposure to ELS (adversity in childhood such as verbal and physical abuse and/or familial dysfunction) is an independent risk factor for CVD and SLE. ELS heightens the risk of developing SLE and SLE patient-reported disease activity, however the underlying mechanism is unclear. We previously showed in a mouse model of ELS, maternal separation with early weaning (MSEW), that mice with pristane-induced SLE develop autoantibodies and increased aortic stiffness earlier in disease progression compared to normally reared (NR) SLE mice. We hypothesized that disease acceleration in MSEW+SLE mice compared to NR+SLE mice is associated with an expansion of B-cells and aortic structural changes. The pristane-induced model of SLE uses an intraperitoneal injection (i.p.) to induce SLE-like symptoms in female mice. The MSEW protocol separates pups from the dam 4h/day (postnatal, PD 2 to 5) and 8h/day (PD 6 to 16) with weaning at PD17. NR litters are weaned at PD21. At 6-8 weeks of age, female mice were randomly assigned to control (CON) or SLE groups: CON received an i.p. PBS injection, while NR+SLE and MSEW+SLE received an i.p. pristane injection. Spleen and thymus were weighed and collected for B-cell subset analysis with flow cytometry and aorta were dissected for histological assessments. At 4 months-post pristane, spleen weights did not differ between groups, however, we observed that MSEW+SLE mice had significantly larger thymus/body weight (BW) compared to CON and NR+SLE mice (p=0.0004 F=7.5 n=4). At 7 months post-pristane or PBS injection, MSEW+SLE mice and NR+SLE mice had significantly higher splenic weights/BW compared to CON mice (p=0.03 F=4.36, n=6) as expected. Using flow cytometry, we found increased thymic %age of CD19+ B-cells in both NR+SLE and MSEW+SLE compared to CON (p<0.0001 F=57.33, n=8,4,4), whereas we found similar %age of CD19+ B-cells in the aorta or spleen of mice in all groups. MSEW+SLE mice had increased germinal center B-cells compared to CON (CON: 0.77%, NR+SLE: 6.0%, MSEW+SLE 7.4%, p=0.008 F=7.08 n=8,4,4) while NR+SLE mice had increased plasma cells compared to CON (CON: 0.08%, NR+SLE: 1.3%, MSEW+SLE 0.68%, p=0.015 F=5.92 n=8,4,4). At 7 months post-pristane, MSEW+SLE mice had significantly greater aortic wall thickness (um) compared to NR+SLE and NR+CON mice (p=0.008 F=11.99, n=3,3,3), however, aortic collagen content (picrosirius red) was similar. These data suggest a difference in B-cell subset expansion and aortic structural changes may contribute to the MSEW driven acceleration of disease activity. Understanding how ELS accelerates autoimmunity and CVD risk is crucial to preventing worsened outcomes in vulnerable populations of individuals exposed to ELS with SLE. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Dysregulated balance in Th17/Treg axis of Pristane-induced lupus mouse model, are mesenchymal stem cells therapeutic?

Despite advances in general and targeted immunosuppressive therapies, limiting all mainstay treatment options in refractory systemic lupus erythematosus (SLE) cases has necessitated the development of new therapeutic strategies. Mesenchymal stem cells (MSCs) have recently emerged with unique properties, including a solid propensity to reduce inflammation, exert immunomodulatory effects, and repair injured tissues. An animal model of acquired SLE mice was induced via intraperitoneal immunization with Pristane and affirmed by measuring specific biomarkers. Bone marrow (BM) MSCs were isolated from healthy BALB/c mice and cultured in vitro, then were identified and confirmed by flow cytometry and cytodifferentiation. Systemic MSCs transplantation was performed and then several parameters were analyzed and compared, including specific cytokines (IL-17, IL-4, IFN-ɣ, TGF-β) at the serum level, the percentage of Th cell subsets (Treg/Th17, Th1/Th2) in splenocytes, and also the relief of lupus nephritis, respectively by enzyme-linked immunosorbent assay (ELISA), flow cytometry analysis and by hematoxylin & eosin staining and also immunofluorescence assessment. Experiments were carried out with different initiation treatment time points (early and late stages of disease). Analysis of variance (ANOVA) followed by post hoc Tukey's test was used for multiple comparisons. The rate of proteinuria, anti-double-stranded deoxyribonucleic acid (anti-dsDNA) antibodies, and serum creatinine levels decreased with BM-MSCs transplantation. These results were associated with attenuated lupus renal pathology in terms of reducing IgG and C3 deposition and lymphocyte infiltration. Our findings suggested that TGF-β (associated with lupus microenvironment) can contribute to MSC-based immunotherapy by modulating the population of TCD4+ cell subsets. Obtained results indicated that MSCs-based cytotherapy could negatively affect the progression of induced SLE by recovering the function of Treg cells, suppressing Th1, Th2, and Th17 lymphocyte function, and downregulating their pro-inflammatory cytokines. MSC-based immunotherapy showed a delayed effect on the progression of acquired SLE in a lupus microenvironment-dependent manner. Allogenic MSCs transplantation revealed the ability to re-establish the balance of Th17/Treg, Th1/Th2 and restore the plasma cytokines network in a pattern dependent on disease conditions. The conflicting results of early versus advanced therapy suggest that MSCs may produce different effects depending on when they are administered and their activation status.

Effect of Red Bean Extract (Phaseolus vulgaris L. Sp) on Interleukin-1, Inhibin Β and PCNA Expression in Systemic Lupus Erythematosus Mice Model

Introduction: Systemic Lupus Erythematosus (SLE) is a complex autoimmune disease characterized by multiple organ involvement. Chronic inflammation due to oxidative stress and autoimmune causes damage to related organs, one of which is the ovary which leads to Premature Ovarian Failure (POF) . Red bean (Phaseolus vulgaris L. Sp.) is an anti-inflammatory and antioxidant agent. This study aims to examine the effect of red beans on IL-1, Inhibin B, and PCNA. Methods: This is a true experimental study with a post-test-only controlled group design in vivo. The sample in this study were female Balb/c mice treated with red bean extract (Phaseolus vulgaris L. sp.) at doses of 50 mg/KgBW (P1), 75 mg/KgBW (P2), and 100 mg/KgBW (P3). IL-1, Inhibin B, and PCNA levels in each group were statistically analyzed using the SPSS 16 for Windows software program. Results: Red bean extract (Phaseolus vulgaris L. Sp.) administration at various doses was statistically proven to significantly reduce IL-1 levels (p<0,05) and increase Inhibin levels in all groups (p<0,05). The highest average Inhibin B levels were found in the 100 mg/KgBW dose group (P3), significant increase in PCNA expression in all groups given various doses of red bean extract (p<0,05). Conclusion: Administration of red bean extract (Phaseoulus vulgaris L. Sp.) can reduce levels of Interleukin-1, increase levels of Inhibin B and PCNA expression in SLE mice.

Targeting type I interferons in systemic lupus erythematous.

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with systemic clinical manifestations including, but not limited to, rash, inflammatory arthritis, serositis, glomerulonephritis, and cerebritis. Treatment options for SLE are expanding and the increase in our understanding of the immune pathogenesis is leading to the development of new therapeutics. Autoantibody formation and immune complex formation are important mediators in lupus pathogenesis, but an important role of the type I interferon (IFN) pathway has been identified in SLE patients and mouse models of lupus. These studies have led to the development of therapeutics targeting type I IFN and related pathways for the treatment of certain manifestations of SLE. In the current narrative review, we will discuss the role of type I IFN in SLE pathogenesis and the potential translation of these data into strategies using type I IFN as a biomarker and therapeutic target for patients with SLE.

A cellular overview of immunometabolism in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a complex autoimmune disease, characterized by a breakdown of immune tolerance and the development of autoantibodies against nucleic self-antigens. Immunometabolism is a rapidly expanding scientific field investigating the metabolic programming of cells of the immune system. During the normal immune response, extensive reprogramming of cellular metabolism occurs, both to generate adenosine triphosphate and facilitate protein synthesis, and also to manage cellular stress. Major pathways upregulated include glycolysis, oxidative phosphorylation, the tricarboxylic acid cycle and the pentose phosphate pathway, among others. Metabolic reprogramming also occurs to aid resolution of inflammation. Immune cells of both patients with SLE and lupus-prone mice are characterized by metabolic abnormalities resulting in an altered functional and inflammatory state. Recent studies have described how metabolic reprogramming occurs in many cell populations in SLE, particularly CD4+ T cells, e.g. favouring a glycolytic profile by overactivation of the mechanistic target of rapamycin pathway. These advances have led to an increased understanding of the metabolic changes affecting the inflammatory profile of T and B cells, monocytes, dendritic cells and neutrophils, and how they contribute to autoimmunity and SLE pathogenesis. In the current review, we aim to summarize recent advances in the field of immunometabolism involved in SLE and how these could potentially lead to new therapeutic strategies in the future.

Cognitive impairment of MRL mice is related to NMDA receptor-mediated inflammatory response and production of adhesion molecules in MRL/lpr mice-derived micro-vascular endothelial cells.

Systemic lupus erythematosus (SLE) is a chronic recurrent autoimmune disease affecting almost all organs. This study was conducted to investigate cognitive impairment of SLE mice (MRL/lpr mice), and explore associated pathological mechanism. Behavior tests (open-field test, elevated plus-maze test, forced swimming test, sucrose preference test, and Morris water maze test) were conducted in MRL/MPJ and MRL/lpr mice. ELISA test was performed to determine levels of antibodies (anti-dsDNA, anti-RPA, anti-ACA, and anti-NR2a/b) and inflammatory factors [tumour necrosis factor a (TNF-a), interleukin (IL)-6, IL-8, and IL-10]. Micro-vascular endothelial cells (MVECs) were isolated, identified, and divided into MVECs (NC), anti-NR2a/2b, memantine, glycine, dexamethasone, and IL-1b groups. Cell proliferation was measured using cell counting kit-8 (CCK-8) assay, and Western blotting was applied to evaluate ELAM-1, VCAM-1, ICAM-1, IKBa, p-IKBa expression. MRL/lpr mice demonstrated lower locomotion/exploration ability, higher anxiety, obvious depression symptoms, lower learning/memory capability compared with MRL/MPJ mice. MRL/lpr mice demonstrated high levels of anti-NR2a/b antibody and auto-antibodies. NMDA receptor antagonist (memantine) significantly increased, and NMDA receptor agonist (glycine) significantly decreased MVECs proliferation compared with NC group ( p < 0.05). Memantine significantly reduced and glycine predominantly enhanced TNF-a, IL-6, IL-8, and IL-10 levels compared with NC group ( p < 0.05). NMDA receptor antagonist and agonist modulated adhesion molecules expression in MVECs. ELAM-1, VCAM-1, and ICAM-1 expressions were significantly down-modulated in memantine group, and remarkably up-modulated in glycine group compared with NC group ( p < 0.05). NMDA receptor antagonist and agonist regulated phosphorylation of p-IKBa. The above effects of memantine evenly equaled to dexamethasone, and glycine evenly equaled to IL-1b. In conclusion, cognitive impairment of MRL mice might be associated with NMDA receptor-mediated inflammatory response and production of adhesion molecules in MRL/lpr mice-derived MVECs.

Endothelin receptor antagonism improves glucose tolerance and adipose tissue inflammation in an experimental model of systemic lupus erythematosus.

Endothelin-1 (ET-1) is elevated in patients with systemic lupus erythematosus (SLE), an autoimmune disease characterized by high rates of hypertension, renal injury, and cardiovascular disease. SLE is also associated with an increased prevalence of obesity and insulin resistance compared to the general population. In the present study, we tested the hypothesis that elevated ET-1 in SLE contributes to obesity and insulin resistance. For these studies, we used the NZBWF1 mouse model of SLE, which develops obesity and insulin resistance on a normal chow diet. To test this hypothesis, we treated control (NZW) and SLE (NZBWF1) mice with vehicle, atrasentan (ETA receptor antagonist, 10 mg/kg/day), or bosentan (ETA/ETB receptor antagonist, 100 mg/kg/day) for 4 wk. Neither treatment impacted circulating immunoglobulin levels, but treatment with bosentan lowered anti-dsDNA IgG levels, a marker of SLE disease activity. Treatment with atrasentan and bosentan decreased glomerulosclerosis, and atrasentan lowered renal T-cell infiltration. Body weight was lower in SLE mice treated with atrasentan or bosentan. Endothelin receptor antagonism also improved hyperinsulinemia, homeostatic model assessment for insulin resistance, and glucose tolerance in SLE mice. Adipose tissue inflammation was also improved by endothelin receptor blockade. Taken together, these data suggest a potential therapeutic benefit for SLE patients with obesity and insulin resistance.NEW & NOTEWORTHY SLE is an autoimmune disease that is associated with obesity, insulin resistance, and elevated endothelin-1. The present study demonstrated that pharmacological inhibition of endothelin receptors decreased body weight, insulin resistance, and adipose tissue inflammation in a murine model of SLE. The therapeutic potential of endothelin receptor antagonists to treat obesity-related diseases and pathophysiological conditions, such as autoimmune diseases and insulin resistance, has become increasingly clear.

Oleocanthal supplemented diet improves renal damage and endothelial dysfunction in pristane-induced systemic lupus erythematosus in mice

Systemic lupus erythematosus (SLE) is a multiorgan disorder with a deregulated immune-inflammatory response. Nutritional therapy has been considered a promising approach to SLE management. Oleocanthal (OLE), the main extra virgin olive oil (EVOO)-derived secoiridoid, has shown to regulate the immune-inflammatory response in various disease contexts; however, its possible beneficial effects on SLE remain unclear. This study sought to evaluate the effects of OLE enriched diet on renal damage and aortic endothelial dysfunction in murine pristane-induced SLE, focusing on the action mechanisms and signaling pathways involved. BALB/c mice were injected with pristane and fed with OLE supplemented diet (0.01 % (w/w)) for six months. Levels of cytokines were measured by ELISA in lipopolysaccharide (LPS)-stimulated peritoneal macrophages and splenocytes. Presence of immunoglobulin G (IgG) and IgM immune complexes were examined by immunofluorescence and immunohistochemistry. Thoracic aortas were used to evaluate endothelial dysfunction. Western blotting was employed to detect signaling pathways and oxidative-inflammatory-related mediators. Dietary OLE supplementation reduced Th1/Th17 pro-inflammatory cytokines production and alleviated renal damage by decreasing immunoglobulin complexes deposition, and inflammation-mediating enzymes expression. The mechanisms underlying these protective effects could be related to the regulation of nuclear factor erythroid 2-related factor 2/Haem oxygenase 1 (Nrf-2/HO-1), mitogen-activated protein kinases (MAPKs), signal transducer and transcription activator of transcription (STAT-3), inflammasome and, nuclear factor kappa B (NF-κB) signaling pathways. Also, dietary OLE improved aortic endothelial dysfunction and vascular reactivity, normalizing endothelial nitric oxide synthase (eNOS) uncoupling, and NADPH oxidase-1 (NOX-1) overexpression. This study shows the immunomodulatory effects of OLE in an in vivo model of SLE by improving renal damage and regulating aortic endothelial dysfunction. These preliminary results provide OLE as a new therapeutic strategy in SLE management.

Systematic characterization of seed overlap microRNA cotargeting associated with lupus pathogenesis

BackgroundCombinatorial gene regulation by multiple microRNAs (miRNAs) is widespread and closely spaced target sites often act cooperatively to achieve stronger repression (“neighborhood” miRNA cotargeting). While miRNA cotarget sites are suggested to be more conserved and implicated in developmental control, the pathological significance of miRNA cotargeting remains elusive.ResultsHere, we report the pathogenic impacts of combinatorial miRNA regulation on inflammation in systemic lupus erythematosus (SLE). In the SLE mouse model, we identified the downregulation of two miRNAs, miR-128 and miR-148a, by TLR7 stimulation in plasmacytoid dendritic cells. Functional analyses using human cell lines demonstrated that miR-128 and miR-148a additively target KLF4 via extensively overlapping target sites (“seed overlap” miRNA cotargeting) and suppress the inflammatory responses. At the transcriptome level, “seed overlap” miRNA cotargeting increases susceptibility to downregulation by two miRNAs, consistent with additive but not cooperative recruitment of two miRNAs. Systematic characterization further revealed that extensive “seed overlap” is a prevalent feature among broadly conserved miRNAs. Highly conserved target sites of broadly conserved miRNAs are largely divided into two classes—those conserved among eutherian mammals and from human to Coelacanth, and the latter, including KLF4-cotargeting sites, has a stronger association with both “seed overlap” and “neighborhood” miRNA cotargeting. Furthermore, a deeply conserved miRNA target class has a higher probability of haplo-insufficient genes.ConclusionsOur study collectively suggests the complexity of distinct modes of miRNA cotargeting and the importance of their perturbations in human diseases.

Polyamines from myeloid-derived suppressor cells promote Th17 polarization and disease progression

Myeloid-derived suppressor cells (MDSCs) are a group of immature myeloid cells that play an important role in diseases. MDSCs promote Th17 differentiation and aggravate systemiclupus erythematosus (SLE) progression by producing arginase-1 to metabolize arginine. However, the metabolic regulators remain unknown. Here, we report that MDSC derivative polyamines can promote Th17 differentiation via miR-542-5p invitro. Th17 polarization was enhanced in response to polyamine treatment or upon miR-542-5p overexpression. The TGF-β/SMAD3 pathway was shown to be involved inmiR-542-5p-facilitated Th17 differentiation. Furthermore, miR-542-5p expression positively correlated with the levels of polyamine synthetases in peripheral blood mononuclear cells of patients with SLE as well as disease severity. In humanized SLE model mice, MDSC depletion decreased the levels of Th17 cells, accompanied by reduced expression of miR-542-5p and these polyamine synthetases. In addition, miR-542-5p expression positively correlated with the Th17 level and disease severity in both patients and humanized SLE mice. Together, our data reveal a novel molecular pathway by which MDSC-derived polyamine metabolism enhances Th17 differentiation and aggravates SLE.

Abstract P073: Long-term Augmentation Of Acetylcholine Bioavailability Halts The Progression Of Lupus Hypertension

Renal inflammation promotes hypertension in systemic lupus erythematosus (SLE). Our recent studies suggest that renal inflammation is regulated by the vagally-mediated cholinergic anti-inflammatory pathway, and that vagal tone is reduced in SLE mice. We found that augmenting central bioavailability of acetylcholine via the acetylcholinesterase inhibitor, galantamine, increases vagal tone and reduces renal inflammation and mean arterial pressure (MAP) in SLE mice after two weeks. However, the long-term efficacy and therapeutic potential of galantamine are unknown. Thus, we hypothesized that chronic galantamine administration would effectively halt the progression of SLE hypertension and renal injury. Starting at 20 weeks of age, female SLE ( NZBWF1 ) and control ( NZW ) mice received galantamine hydrobromide (3 mg/kg/day, SQ) or vehicle continuously for 16 weeks via osmotic minipump. At 35 weeks, mice were placed in metabolic cages for urine collection, carotid catheters were implanted to assess MAP in conscious mice, and tissues were harvested. MAP (mmHg, n=4-6) was higher in SLE mice than controls (161.9±9.9 vs. 128.3±0.9, p=0.001) and long-term galantamine treatment prevented further increases in MAP in SLE mice (161.9±9.9 vs. 138.3±4.9, p= 0.01). Survival rate was lower in SLE mice compared to controls (50% vs. 100%) and galantamine improved survival to 70% in SLE mice. Eighty percent (4 of 5) of SLE mice had urinary albumin over 300 mg/dL and chronic galantamine lowered the prevalence to 57% (4 of 7); no controls had albuminuria. There was no difference in CD3+CD4+ T cells amongst groups, but the percentage of renal CD3+CD8+ T cells was increased in SLE mice compared to controls (29.7±2.2 vs. 12.8±0.79, p&lt;0.0001, n=4-7) and galantamine reduced this percentage in SLE mice (29.7±2.2 vs. 22.9±1.2, p=0.0261). Taken together, our data indicate chronic augmentation of central acetylcholine bioavailability is protective against SLE hypertension since it improves survival rate, decreases renal injury and alters cytotoxic renal immune cell populations. These data further support acetylcholinesterase inhibition as a novel therapeutic option for hypertension associated with autoimmunity.

Abstract 097: Seasonal Travel Stressors Modulates Hypertension In Adult Female Lupus Mice

Systemic lupus erythematosus (SLE) is an autoimmune disorder linked to chronic renal inflammation and prevalent hypertension. We use an established murine model of SLE (NZBWF1) to mechanistically link renal inflammation to the development of hypertension. SLE mice travel to our university pre-puberty (3-6 weeks), develop autoantibodies by 20 weeks, and are consistently hypertensive by 35 weeks. We observed that when mice travel in the summer, autoantibody production is higher as the mice age vs. those that travel in the winter. This association was heightened in a subset of SLE mice that traveled to our university as adults (18-19 weeks), suggesting a role of seasonal factors, travel stressors, and age in altering disease severity. It is unknown whether these seasonal and environmental stressors can also alter blood pressure and inflammatory processes. Thus, we hypothesized that travel-induced seasonal stressors exacerbate hypertension and renal inflammation in adult SLE-prone mice. Female SLE mice traveled to our university in summer or winter at 3-6 or 18-19 weeks and were implanted with carotid catheters once they reached 35 weeks to assess mean arterial pressure (MAP). Mice were then euthanized and tissues collected to monitor plasma and renal interleukin (IL)-6, a proinflammatory cytokine. No seasonal differences were found in MAP of mice that traveled pre-puberty in summer (n = 17) and winter (n = 39) (143.6 ± 3.5 vs. 140.2 ± 2.2 mmHg; p = 0.4096) nor in plasma IL-6 (26.06 ± 7.25 vs. 15.54 ± 8.622 pg/mL; p = 0.2370) or renal IL-6 (0.01156 ± 0.00603 vs. 0.01099 ± 0.00523 pg/μg; p = 0.9445). Conversely, adult SLE mice that traveled in summer had higher MAP than those that traveled in winter (136.12 ± 2.63 vs. 128.81 ± 1.55 mmHg; p = 0.0339; n = 5-7), as well as higher plasma IL-6 (723.28 ± 220.72 vs. 280.73 ± 67.99 pg/mL; p = 0.0339) and renal IL-6 (0.078956 ± 0.017192 vs. 0.023413 ± 0.003801 pg/μg; p &lt; 0.0001). Together, our data indicate that hypertension and renal inflammation in mice subjected to travel stress as adults is seasonally dependent. Since there were no seasonal differences in hypertension in SLE mice that traveled pre-puberty, there may be a factor related to age, seasonal environmental factors, and/or timing of the stressors that is causing the detrimental effect.