Serum anti-dsDNA Antibody Research Articles

Long-term outcome of tacrolimus-based immunosuppressive treatment for patients with paediatric-onset lupus nephritis.

We have previously reported the mid-term efficacy and safety of tacrolimus (Tac)-based immunosuppressive therapy in such patients, and herein, we aimed to determine their long-term outcomes (over 10 years). We retrospectively evaluate the data of 13 consecutive patients with biopsy-proven long-standing LN who underwent a long-term Tac-based treatment regimen. Tac was administered once daily at a dose of 3 mg as reinduction or maintenance treatment. Treatment outcomes were defined using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), urinary protein/creatinine ratio (Up/cr), serum creatinine, estimated glomerular filtration rate (eGFR) and serological lupus markers (complement C3, complement hemolytic activity [CH 50], and anti-dsDNA antibody titre), and the concomitantly administered prednisolone (PDN) dose. Data on clinical parameters and serological lupus activity were collected annually from each patient throughout the study period. The patients' baseline characteristics at the treatment initiation were as follows: mean age, 18 years; Up/cr, 0.63 ± 0.69; serum C3 level, 57.2 ± 22.4 mg/dL (normal range, 79-152 mg/dL); CH50, 27.9 ± 15.7 U/mL (normal range, 23.0-46.0 U/mL); serum anti-dsDNA antibody titre, 111.7 ± 123.4 IU/mL (normal range, <12.0 IU/mL); serum creatinine, 0.60 ± 0.19 mg/dL; eGFR, 115.6 ± 21.3 mL/min and SLEDAI, 13 ± 8.1. Despite the gradual tapering of the concomitantly administered PDN dose from 18.7 ± 13.5 mg/day at baseline to 3.5 ± 2.8 mg/day at 10 years (p = .002), a marked improvement in the outcomes, compared with the baseline values, was observed within a year. Additionally, these favourable changes persisted throughout study period in most patients. Compared with the baseline values, the following measures confirmed sustained outcome improvements after a 10-year treatment: SLEDAI, 1.7 ± 2.0; serum C3 level, 83.8 ± 16.1 mg/dL; CH50, 45.6 ± 10.9 U/mL (all p < .01) and Up/cr, 0.16 ± 0.18 and serum anti-dsDNA antibody titre, 25.8 ± 28.8 IU/mL (both p < .05). Serum creatinine level and eGFR remained within the normal range in all study participants except for one patient who experienced several flare-ups. No serious adverse effects were observed. Our results suggest that long-term Tac-based immunosuppressive treatment as maintenance therapy is beneficial and has low cytotoxicity. Therefore, it represents an attractive option for the treatment of selected patients with paediatric-onset LN in a real-world setting.

B-Cell Maturation Antigen (BCMA) as a Biomarker and Potential Treatment Target in Systemic Lupus Erythematosus.

The BAFF-APRIL system is crucial for the pathogenesis of systemic lupus erythematosus (SLE) by promoting B cell survival, differentiation and the maintenance of humoral autoimmunity. Here, we investigated the relationship of BCMA expression on B cell subsets with its ligands BAFF and APRIL, together with soluble BCMA, and with clinical and serologic variables in a cohort of 100 SLE patients (86 under conventional and 14 under belimumab therapy) and 30 healthy controls (HCs) using multicolor flow cytometry and ELISA. We found that BCMA expression in SLE patients was significantly increased on all B cell subsets compared to HCs, with all examined components of the BAFF-APRIL system being upregulated. BCMA expression was significantly increased on switched and unswitched memory B cells compared to naïve B cells, both in HCs and SLE. BCMA expression on B cells correlated with plasmablast frequencies, serum anti-dsDNA antibodies and complement consumption, while soluble BCMA correlated with plasmablast frequency, highlighting its potential as a clinical biomarker. Belimumab treatment significantly reduced BCMA expression on most B cell subsets and soluble TACI and contributed to the inhibition of almost the entire BAFF-APRIL system and restoration of B cell homeostasis. These results provide insights into the complex dysregulation of the BAFF-APRIL system in SLE and highlight the therapeutic potential of targeting its components, particularly BCMA, in addition to its use as a biomarker for disease activity.

Zebra Bodies in the Kidney: Is it a Pathognomonic Finding of Fabry Disease?

Zebra bodies are intralysosomal lamellar inclusion bodies. It is accepted as a specific feature of Fabry disease. However, it has been reported in many hereditary and acquired conditions. We are reporting Zebra bodies in the kidneys of cases with Rheumatoid Arthritis and hydroxychloroquine-induced phospholipidosis. Case 1: A 55-year-old male presented with hypertension and renal dysfunction. Serum ANA and anti-CCP antibodies were positive. A kidney biopsy revealed chronic tubulointerstitial nephritis with Zebra Bodies in the podocytes. Genetic analysis was negative for Fabry disease. Case 2: A 34-year-old female with Systemic Lupus Erythematosus on Hydroxychloroquine for a year presented with subnephrotic proteinuria. Serum ANA and anti-dsDNA antibodies were positive. Electron microscopy showed lamellated osmiophilic inclusion bodies in the tubular and visceral epithelial cells. Thus, Zebra bodies are not pathognomonic for Fabry disease and Rheumatoid Arthritis should also be considered in the differential diagnosis, particularly if family or drug history is negative.

Association of urine autoantibodies with disease activity in systemic lupus erythematosus.

The presence of urinary autoantibodies in patients with systemic lupus erythematosus (SLE) has been confirmed by several studies; however, the significance of their presence in urine remains unclear. This study aims to further investigate the association between urine autoantibodies and disease activity as well as organ involvement in SLE. This cross-sectional study included 89 SLE patients. Data collected included anti-nuclear antibody (ANA), anti-ENA antibodies, and anti-dsDNA antibody levels in both serum and urine, complement (C) 3, C4 levels in serum, SLE disease activity index-2000 (SLEDAI-2000), renal domains of SLEDAI (RSLEDAI) and non-renal SLEDAI (NRSLEDAI). The rate of positive urine ANA (uANA) was 33.3% (29/87) among the enrolled patients. Compared to the uANA negative group, the positive group exhibited significantly higher SLEDAI-2000 scores (7.85 ± 5.88 vs. 18.69 ± 6.93, p < 0.001), RSLEDAI scores [0 (0, 4.0) vs. 12.0 (8.0, 16.0), p < 0.001], and NRSLEDAI [4 (2.0, 8.0) vs. 6.0 (4.0, 9.5), p = 0.038]. Patients with positive urine anti-Sm antibody demonstrated significantly elevated SLEDAI-2000 scores compared to those who were negative (25.0 ± 8.80 vs. 10.09 ± 6.63, p < 0.001). Similarly, they also had higher RSLEDAI [16.0 (12.0, 16.0) vs. 4.0 (0, 8.0), p < 0.001] and NRSLEDAI [9.5 (6.0, 13.5) vs. 4.0 (3.0, 8.0), p = 0.012], as well as a greater prevalence of renal involvement compared to their negative counterparts (100% vs. 58.2, p = 0.022). There was a positive correlation between uANA titer and both SLEDAI-2000 (rs = 0.663, p < 0.001) and RSLEDAI (rs = 0.662, p < 0.001). The serum anti-dsDNA antibody level did not exhibit a significant correlation with RSLEDAI (rs = 0.143, p = 0.182). Conversely, the urine anti-dsDNA antibody level demonstrated a significant positive correlation with RSLEDAI (rs = 0.529, p < 0.001). Urine ANA is associated with both global SLEDAI and RSLEDAI scores. Urine anti-Sm antibody is associated with an increased incidence of renal involvement in SLE. The urine anti-dsDNA antibody level, rather than the serum anti-dsDNA antibody level, exhibits a significant association with RSLEDAI in SLE.

Anti-complement factor H (CFH) autoantibodies could delay pristane-induced lupus nephritis

PurposeAnti-complement factor H (CFH) autoantibodies could be detected in lupus and its significance remained to be elucidated. Herein, we aimed to explore the roles of anti-CFH autoantibodies based on pristane-induced lupus mice.MethodsTwenty-four female Balb/c mice were randomly divided into four groups, with one group injected with pristane (pristane group), one group with pristane and then human CFH (hCFH) (pristane-CFH group) 3 times, and the other two as vertical controls, PBS group and PBS-CFH group. Histopathological analysis was performed six months after pristane administration. Levels of hCFH, anti-CFH autoantibodies and anti-dsDNA antibody were detected. Murine IgG (mIgG) were purified and cross-reactivity, epitopes, subclasses and functional analysis were further evaluated in vitro.ResultsImmunization with hCFH and subsequent development of anti-CFH autoantibodies significantly attenuated nephritis of pristane-induced lupus, including lower levels of urinary protein and serum creatinine, decreased levels of serum anti-dsDNA antibody, greatly ameliorated renal histopathologic damage, decreased IgG, complements (C1q, C3) deposits and lower inflammatory factor (IL-6) expression in glomerulus. Furthermore, the purified mIgG (contained anti-CFH autoantibodies) could recognize both hCFH and murine CFH, and the epitopes were predominantly located in hCFH short consensus repeats (SCRs) 1–4, 7 and 11–14. The IgG subclasses were predominant IgG1. The autoantibodies could enhance the binding between hCFH and C3b, and increase factor I mediated-C3b lysis in vitro.ConclusionOur results suggested that anti-CFH autoantibodies could attenuate pristane-induced lupus nephritis by increasing bio-functions of CFH on regulating complement activation and controlling inflammation.

Phenotypic Evaluation of TREX1 Null Mice as a Model for Lupus-Like Autoimmune Disease

Abstract TREX1 (DNase III) is the major mammalian 3’-5’ DNA exonuclease and thought to play a major role in cell death and genomic DNA degradation. Dysfunction of Trex1 has been suggested to activate immune response by self DNA, as TREX1 null mice develop inflammatory myocarditis similar to autoimmune cardiomyopathy and produce type 1 IFN. TREX1 D18N causes a monogenic cutaneous form of lupus called familial chilblain lupus and exhibits dysfunctioned dsDNA-degrading activity, providing a link between dsDNA degradation and nucleic acid-mediated autoimmune diseases. Using CRISPR-Cas9, we generated a Trex1 −/−mouse by knocking out exon 2 and performed comprehensive phenotypic analyses to evaluate the loss of function of TREX1 and its potential application in SLE research. Both female and male TREX1 null mice showed dramatically increased post-wean morbidity and significantly increased serum ALT, AST and LDH levels, compared to wildtype and heterozygotes from 6 to 24 weeks of age, indicating liver and heart injuries. Pathohistological analysis showed inflammatory immune cell infiltration in liver, heart, spleen, kidney, lung and skin among TREX1 null mice. Serum anti-dsDNA antibody levels were significantly increased and remained high from 7 to 25 weeks of age, consistent with Trex1’s being the major DNA exonuclease. Urine protein to creatinine ratio was dramatically increased at 28 weeks of age among TREX1 null mice. In conclusion, the Trex1 −/−mice we generated in this work showed lupus-like inflammatory autoimmune responses in multiple organs, providing an urgently needed tool to study Trex1-mediated autoimmunity and to evaluate potential therapeutic treatments for lupus.

Increased levels of IL-17 and autoantibodies following Bisphenol A exposure were associated with activation of PI3K/AKT/mTOR pathway and abnormal autophagy in MRL/lpr mice

Bisphenol A (BPA) is a common environmental endocrine disruptor which mimic the effect of estrogen. The immunotoxicity of BPA has attracted widespread attention in recent years. However, the effects and mechanism of BPA on autoimmune disease were rarely reported. Systemic lupus erythematosus (SLE) is a typical autoimmune disease, and its etiology and mechanism are complex and unclear. Currently, inflammation and the production of autoantibodies are considered to be important pathological mechanisms of SLE, and estrogen contributes to the occurrence and development of SLE. Therefore, in order to explore whether BPA exposure can affect the development of SLE and its possible mechanism, we used MRL/lpr (lupus-prone mice) and C57/BL6 female mice exposed to 0.1 and 0.2 µg/mL BPA for 6 weeks. We discovered that BPA exposure increased the concentration of serum anti-dsDNA antibody and IL-17, and the level of RORγt protein (the transcription factor of Th17 cells). Moreover, there were higher expression of p-PI3K, p-AKT, p-mTOR, ULK, Rubicon, P62, Becline1 and LC3 protein in spleen tissue of BPA exposed MRL/lpr mice compared with the control. However, there were no significant changes in the expression of IL-17, RORγt or mTOR in C57 mice exposed to BPA at the same dose. Our study implied that BPA exposure induced the development of SLE, which might be related to the up-regulation of PI3K/AKT/mTOR signaling pathway and abnormal autophagy. Our study indicated that lupus mice were more susceptible to BPA, and provided a new insight into the mechanism by which BPA exacerbated SLE. Therefore, our study suggested that autoimmune patients and susceptible population should be considered when setting thresholds for environmental BPA exposure.

Interleukin-33 Ameliorates Murine Systemic Lupus Erythematosus and Is Associated with Induction of M2 Macrophage Polarisation and Regulatory T Cells

The innate cytokine IL-33 is increasingly recognised to possess biological effects on various immune cells. We have previously demonstrated elevated serum level of soluble ST2 in patients with active systemic lupus erythematosus suggesting involvement of IL-33 and its receptor in the lupus pathogenesis. This study sought to examine the effect of exogenous IL-33 on disease activity of pre-disease lupus-prone mice and the underlying cellular mechanisms. Recombinant IL-33 was administered to MRL/lpr mice for 6 weeks, whereas control group received phosphate-buffered saline. IL-33-treated mice displayed less proteinuria, renal histological inflammatory changes, and had lower serum levels of pro-inflammatory cytokines including IL-6 and TNF-α. Renal tissue and splenic CD11b+ extracts showed features of M2 polarisation with elevated mRNA expression of Arg1, FIZZI, and reduced iNOS. These mice also had increased IL-13, ST2, Gata3, and Foxp3 mRNA expression in renal and splenic tissues. Kidneys of these mice displayed less CD11b+ infiltration, had downregulated MCP-1, and increased infiltration of Foxp3-expressing cells. Splenic CD4+ T cells showed increased ST2-expressing CD4+Foxp3+ population and reduced IFN-γ+ population. There were no differences in serum anti-dsDNA antibodies and renal C3 and IgG2a deposit in these mice. Exogenous IL-33 was found to ameliorate disease activity in lupus-prone mice with induction of M2 polarisation, Th2 response, and expansion of regulatory T cells. IL-33 likely orchestrated autoregulation of these cells through upregulation of ST2 expression.

Immunomodulatory effects of atorvastatin on MRL/lpr mice

BackgroundStatins have long been extensively prescribed as effective lipid-lowering agents, but statins have also been recognized as novel immunomodulators in recent years. This study was designed to investigate the immunomodulatory effects of atorvastatin on lupus-prone MRL/lpr mice.MethodsA total of 30 8-week-old female MRL/lpr mice were randomly divided into three groups and orally administered vehicle, atorvastatin orhydroxychloroquine sulfate for 11 weeks. In vivo, the effects of atorvastatin on the survival rate, renal function and spleen index in MRL/lpr mice were examined. Ex vivo, splenic B-cell proliferation was assessed by a Cell Counting Kit-8.ResultsOral atorvastatin failed to prolong survival time, or reduce the levels of proteinuria, or serum anti-dsDNA antibody and complement proteins (C3, C4). Histologically, no significant improvement by atorvastatin was observed in the pathological manifestations of renal damage, while hydroxychloroquine sulfate significantly improved glomerular injury. Ex vivo, atorvastatin suppressed the proliferation of splenic B lymphocytes.ConclusionOral atorvastatin monotherapy had no therapeutic effects on MRL/lpr mice, whereas atorvastatin inhibited splenic B-cell proliferation in vitro, suggesting that atorvastatin has a potential therapeutic effect on systemic lupus erythematosus.

CD56brightCD16- to CD57+CD56dimCD16+ NK cell ratio discriminates disease activity and renal involvement in patients with systemic lupus erythematosus.

We aimed to discriminate subpopulations of peripheral natural killer (NK) cells of patients with systemic lupus erythematosus (SLE) and evaluate their usability in monitoring disease activity. The total number of NK cells and their subpopulations were determined by flow cytometry in 68 patients with SLE and 35 healthy controls. Clinical data were extracted from medical records, including serum anti-double-stranded-DNA (anti-dsDNA), complement C3 and C4, and urine protein. Disease activity in patients with SLE was assessed using the SLE Disease Activity Index-2000 (SLEDAI-2K). The percentages and absolute numbers of NK cells decreased, and the proportions of three major NK cell subsets defined by cell maturation status altered in SLE patients. The frequency of CD56brightCD16- NK (immature, Im NK) cells increased, while that of the CD57+CD56dimCD16- subset (mature, more differentiated, MD NK) decreased in patients with high-activity SLE, resulting in a significant increase in the Im NK-to-MD NK ratio as compared with that in patients with low-activity SLE. The area under the receiver operating characteristic curve indicated that the ratio was 0.722 in severe SLE and 0.773 in lupus nephritis, with optimal cut-off levels of 0.075 and 0.108, respectively. The ratio correlated positively with the SLEDAI-2K score, proteinuria, and serum anti-dsDNA antibody levels but negatively with C3 and C4 levels. Our data indicate that the imbalance in Im NK and MD NK cells may play a role in lupus development and serve as a predictive biomarker to assess disease activity and renal involvement in patients with SLE.

Supplemental hydroxychloroquine therapy regulates adipokines in patients with systemic lupus erythematosus with stable disease.

In patients with systemic lupus erythematosus (SLE), a higher frequency of atherosclerotic lesions is associated with poor prognosis. Hydroxychloroquine (HCQ) has been reported to improve the lifespan and the prognosis of dyslipidaemia in patients with SLE, but the mechanism is unclear. We investigated the effect of supplemental HCQ treatment on the levels of serum cytokines associated with atherosclerosis in patients with stable SLE. Patients with SLE who received supplemental HCQ and maintained low disease activity between January 2016 and September 2020 were included in this study. Disease activity was assessed using Safety of Estrogens in Lupus National Assessment-SLE Disease Activity Index, Cutaneous Lupus Erythematous Disease Area and Severity Index, and Lupus Low Disease Activity State. Serum complement titres, anti-dsDNA antibodies, and serum cytokines (adiponectin, resistin, and leptin) were analyzed before and after HCQ treatment. Forty-one patients (4 males and 37 females, mean age 41.3 ± 13.2years) were included. Serum adiponectin levels were significantly increased after 3months of HCQ treatment compared to baseline, and serum resistin levels were significantly reduced. The change in serum resistin level after HCQ administration was correlated with a significant reduction in serum TNF-α, interleukin (IL)-6, IL-8, and IL-1RA levels. Supplemental HCQ treatment in patients with SLE improved adipokine levels. HCQ may improve prognosis by controlling disease activity in SLE and reducing risk factors for atherosclerosis. Key Points • Hydroxychloroquine has been reported to improve the prognosis of dyslipidaemia in patients with SLE, but the underlying mechanism is unclear. • In this study, hydroxychloroquine improved adipokine levels in patients with SLE, implicating adipokines as a potential mechanism underlying the benefit of hydroxychloroquine on dyslipidaemia. • Supplemental hydroxychloroquine should be considered in patients with SLE harboring lipid abnormalities and risk factors for atherosclerosis.

Safety and efficacy of fecal microbiota transplantation for treatment of systemic lupus erythematosus: An EXPLORER trial

Gut microbiota dysbiosis is involved in the development of systemic lupus erythematosus (SLE). The safety and efficacy of fecal microbiota transplantation (FMT) for the treatment of SLE patients has not been explored. In this 12-week, single-arm pilot clinical trial of oral encapsulated fecal microbiome from healthy donors to patients with active SLE, we aimed to evaluate the safety and efficacy of FMT in patients with SLE (ChiCTR2000036352). 20 SLE patients with SLEDAI ≥6 were recruited. FMT was administered once a week for three consecutive weeks along with standard treatment and the patients were followed for 12 weeks. Safety was evaluated throughout the trial. The primary endpoint was the SLE Responder Index-4 (SRI-4) at week 12. Microbiome composition, levels of short chain fatty acids (SCFAs) in the gut and of cytokines in the sera were measured along with lymphocyte phenotyping. No serious adverse events were observed after FMT. At week 12, the SRI-4 response rate was 42.12%, and significant reductions in the SLEDAI-2K scores and the level of serum anti-dsDNA antibody were observed compared to baseline. Significant enrichment of SCFAs-producing bacterial taxa and reduction of inflammation-related bacterial taxa were observed, along with increased production of SCFAs in the gut and reduced levels of IL-6 and CD4+ memory/naïve ratio in the peripheral blood. Furthermore, SRI-4 responding patients displayed specific microbiota signatures both before and after FMT. The first clinical trial of FMT in active SLE patients provide supportive evidence that FMT might be a feasible, safe, and potentially effective therapy in SLE patients by modifying the gut microbiome and its metabolic profile.

The Ameliorative Effect of Dexamethasone on the Development of Autoimmune Lung Injury and Mediastinal Fat-Associated Lymphoid Clusters in an Autoimmune Disease Mouse Model.

In our previous study, we revealed the ameliorative therapeutic effect of dexamethasone (Dex) for Lupus nephritis lesions in the MRL/MpJ-Fas lpr/lpr (Lpr) mouse model. The female Lpr mice developed a greater number of mediastinal fat-associated lymphoid clusters (MFALCs) and inflammatory lung lesions compared to the male mice. However, the effect of Dex, an immunosuppressive drug, on both lung lesions and the development of MFALCs in Lpr mice has not been identified yet. Therefore, in this study, we compared the development of lung lesions and MFALCs in female Lpr mice that received either saline (saline group “SG”) or dexamethasone (dexamethasone group “DG”) in drinking water as a daily dose along with weekly intraperitoneal injections for 10 weeks. Compared to the SG group, the DG group showed a significant reduction in the levels of serum anti-dsDNA antibodies, the size of MFALCs, the degree of lung injury, the area of high endothelial venules (HEVs), and the number of proliferating and immune cells in both MFALCs and the lungs. A significant positive correlation was observed between the size of MFALCs and the cellular aggregation in the lungs of Lpr mice. Therefore, this study confirmed the ameliorative effect of Dex on the development of lung injury and MFALCs via their regressive effect on both immune cells’ proliferative activity and the development of HEVs. Furthermore, the reprogramming of MFALCs by targeting immune cells and HEVs may provide a therapeutic strategy for autoimmune-disease-associated lung injury.

3-hydroxy butyrate dehydrogenase 2 deficiency aggravates systemic lupus erythematosus progression in a mouse model by promoting CD40 ligand demethylation

ABSTRACT The implications of the CD40-CD40 ligand (CD40L) signaling pathway in systemic lupus erythematosus (SLE) were well documented, due to its important role among immune cells. Previous research found that 3-hydroxy butyrate dehydrogenase 2 (BDH2), a modulator of intracellular iron homeostasis and iron transportation promoted the pathogenic process of SLE by regulating the demethylation of cd70, cd11a, and cd40l genes among CD4 + T cells. The purpose of this study was to explore the role of BDH2 in oxidative damage-induced SLE. First, CD4 + T cells treated with H2O2 were injected into the tail vein of mice to establish a lupus model. CD40L knockdown significantly decreased CD40L expression on CD4 + T cells in the spleen of SLE mice. Compared with SLE model mice, the levels of serum anti-dsDNA antibody and urinary protein in the CD40L interference group were significantly decreased. CD40L knockdown alleviated the immune complex glomerulonephritis in syngeneic SLE mice. Moreover, the levels of IFN-γ and IL-2 were decreased. However, IL-4 and IL-10 levels were significantly upregulated in the serum of CD40L knockdown SLE mice, compared with SLE model mice. Accordingly, CD40L knockdown reduced Th1/Th2 percentage in SLE mice. Inhibiting the expression of BDH2 of CD4 + T cells promoted the demethylation of CD40L, while it inhibited cell proliferation, elevated oxidative stress through increased expression of CD40L, and thus, promoted the progress of SLE. Our results demonstrate that BDH2 aggravates the pathologic progression of SLE in mice, by increasing the demethylation level of CD40L among CD4 + T cells.

Therapeutic effects of cationic liposomes on lupus-prone MRL/lpr mice are mediated via inhibition of TLR4-triggered B-cell activation

We previously reported that co-delivery of dihydroartemisinin and high mobility group box 1 (HMGB1) siRNAs, using cell penetrating peptide (TAT)-modified cationic liposomes (TAT-CLs-DHA/siRNA), resulted in promising activity for the treatment of inflammatory disease through TLR4 signaling pathway. In the current study, we further investigated the therapeutic effects of TAT-CLs-DHA/siRNA on lupus-prone MRL/lpr mice and explored its effects on B cell responses. In vitro, we found that TAT-CLs-DHA/siRNA suppressed the proliferation and activation of B cells through the TLR4 signaling pathway. Following parenteral administration every 4 days, TAT-CLs-DHA/siRNA significantly reduced proteinuria, glomerulonephritis, serum anti-dsDNA antibody and secretion of interleukin (IL)-6, IL-10, IL-17 and IL-21. Moreover, Western blotting showed that TAT-CLs-DHA/siRNA modulated the B-cell intrinsic pathway by downregulating expression of HMGB1, TLR4, MyD88 and NF-κB. This co-delivery system thus represents a promising treatment option for lupus nephritis, and also highlights a novel target of lupus treatment through B cell TLR4 signal pathway.

Role of vitamin D/VDR nuclear translocation in down-regulation of NF-κB/NLRP3/caspase-1 axis in lupus nephritis

BackgroundVitamin D receptor (VDR) and NLRP3 inflammasome play critical roles in lupus nephritis (LN) pathogenesis. Aim of the study:This study explored the therapeutic effect of VDR agonist on LN and its molecular mechanism to inhibit NLRP3 signalling. MethodsC57BL/6 mice, lupus-prone MRL/lpr mice, and VDR agonist paricacitol-treated MRL/lpr mice (300 ng/kg/mouse per dose, 5 times/week for 8 weeks from 8 weeks old) were used to assess kidney histopathology and measure proteinuria, serum anti-ds-DNA antibody and expression of NF-κB/NLRP3/caspase-1/IL-1β/IL-18 axis. We used mouse renal tubular epithelial cells (mRTECs) to identify protein–protein interactions and examine the effects of paricalcitol. Results and Conclusion:LN pathogenesis decreased after paricalcitol treatment. We observed a marked improvement in renal pathology and a time-dependent decrease urine protein and serum anti-dsDNA antibody levels. In 16-week-old MRL/lpr LN mice, the upregulated expression of NLRP3/caspase-1/IL-1β/IL-18 axis was significantly downregulated after paricalcitol treatment. Paricalcitol can reverse the apoptosis induced by anti-dsDNA antibody via the NF-κB/NLRP3/caspase-1/IL-1β/IL-18 axis in mRTECs. Furthermore, paricalcitol suppressed NF-κB nuclear translocation by competitively binding to importin-4. In summary, the VDR agonist can alleviate LN by modulating the NF-κB/NLRP3/caspase-1/IL-1β/IL-18 axis and suppressing the NF-κB nuclear translocation.

The expansion of activated naive DNA autoreactive B cells and its association with disease activity in systemic lupus erythematosus patients

BackgroundAutoreactive B cells are well recognized as key participants in the pathogenesis of systemic lupus erythematosus (SLE). However, elucidating the particular subset of B cells in producing anti-dsDNA antibodies is limited due to their B cell heterogeneity. This study aimed to identify peripheral B cell subpopulations that display autoreactivity to DNA and contribute to lupus pathogenesis.MethodsFlow cytometry was used to detect total B cell subsets (n = 20) and DNA autoreactive B cells (n = 15) in SLE patients’ peripheral blood. Clinical disease activities were assessed in SLE patients using modified SLEDAI-2 K and used for correlation analyses with expanded B cell subsets and DNA autoreactive B cells.ResultsThe increases of circulating double negative 2 (DN2) and activated naïve (aNAV) B cells were significantly observed in SLE patients. Expanded B cell subsets and DNA autoreactive B cells represented a high proportion of aNAV B cells with overexpression of CD69 and CD86. The frequencies of aNAV B cells in total B cell populations were significantly correlated with modified SLEDAI-2 K scores. Further analysis showed that expansion of aNAV DNA autoreactive B cells was more related to disease activity and serum anti-dsDNA antibody levels than to total aNAV B cells.ConclusionOur study demonstrated an expansion of aNAV B cells in SLE patients. The association between the frequency of aNAV B cells and disease activity patients suggested that these expanded B cells may play a role in SLE pathogenesis.

Redox-sensitive Nrf2 and MAPK signaling pathways contribute to trichloroethene-mediated autoimmune disease progression

Trichloroethene (TCE) exposure is associated with the induction of autoimmune diseases (ADs). Although oxidative stress plays a major role in TCE-mediated autoimmunity, the underlying molecular mechanisms still need to be delineated. Dysregulation of redox-sensitive nuclear factor (erythroid-derived 2)-like2 (Nrf2), resulting in uncontrolled antioxidant and cytoprotective genes, and pro-inflammatory MAPK signaling pathways could be critical in TCE-mediated disease progression. This study was, therefore, focused on establishing status and contribution of Nrf2 and MAPK signaling in TCE-mediated inflammatory and autoimmune responses, especially during disease progression. To achieve these objectives, time-response studies were conducted by treating female MRL+/+ mice with TCE (0.5 mg/mL, a dose relevant to human exposure) for 24, 36 and 52 wks. TCE exposure led to reduction in Nrf2 expression, but increased phos-NF-κB (p65) and iNOS along with increased phosphorylation of MAPKs (p38, ERK and JNK) and downstream pro-inflammatory cytokines IL-12, TNF-α and RANTES in the livers in a time-dependent manner. These changes were also associated with time-dependent increases in liver protein carbonyls and induction of serum anti-dsDNA antibodies (marker of systemic lupus erythematosus disease), further supporting the role of oxidative stress and Nrf2/MAPK signaling in TCE-mediated autoimmune response progression. The mechanistic role of MAPK in TCE-mediated autoimmunity was further established by treating MRL+/+ mice with sulforaphane (SFN; 8 mg/kg, i.p., every other day) along with TCE (10 mmol/kg, i.p., every 4th day) for 6 wks using an established protocol, and by in vitro treatment of T cells with dichloroacetyl chloride (a TCE metabolite) with/without p38 MAPK inhibitor. SFN treatment attenuated the TCE-mediated phosphorylation of p38 MAPK. More importantly, treatment with SFN or p38 inhibitor led to suppression of downstream pro-inflammatory cytokines IL-12 and TNF-α. These findings thus support the contribution of Nrf2 and MAPK signaling pathways and help in delineating novel potential therapeutic targets against TCE-mediated autoimmunity.

SH3BP2 Deficiency Ameliorates Murine Systemic Lupus Erythematosus.

Background: The adaptor protein Src homology 3 domain-binding protein 2 (SH3BP2) is widely expressed in immune cells. It controls intracellular signaling pathways. The present study was undertaken to investigate the role of SH3BP2 in a murine systemic lupus erythematosus model. Methods: For the lupus model, we used Faslpr/lpr mice. Clinical and immunological phenotypes were compared between Faslpr/lpr and SH3BP2-deficient Faslpr/lpr mice. Splenomegaly and renal involvement were assessed. Lymphocyte subsets in the spleen were analyzed by flow cytometry. To examine the role of SH3BP2 in specific cells, B cell-specific SH3BP2-deficient lupus mice were analyzed; T cells and bone marrow-derived dendritic cells and macrophages were analyzed in vitro. Results: SH3BP2 deficiency significantly reduced lupus-like phenotypes, presented as splenomegaly, renal involvement, elevated serum anti-dsDNA antibody, and increased splenic B220+CD4−CD8− T cells. Notably, SH3BP2 deficiency in B cells did not rescue the lupus-like phenotypes. Furthermore, SH3BP2 deficiency did not substantially affect the characteristics of T cells and macrophages in vitro. Interestingly, SH3BP2 deficiency suppressed the differentiation of dendritic cells in vitro and reduced the number of dendritic cells in the spleen of the lupus-prone mice. Conclusions: SH3BP2 deficiency ameliorated lupus-like manifestations. Modulating SH3BP2 expression could thus provide a novel therapeutic approach to autoimmune diseases.

Azithromycin alleviates systemic lupus erythematosus via the promotion of M2 polarisation in lupus mice

Our previous study demonstrated that azithromycin could promote alternatively activated (M2) macrophages under lupus conditions in vitro, which might be beneficial for lupus treatment. Thus, the aim of this study was to further confirm whether azithromycin can drive M2 polarisation in lupus and ultimately alleviate systemic lupus erythematosus (SLE) in vivo. Lymphocyte-derived DNA (ALD-DNA)-induced mice (induced lupus model) and MRL-Faslpr mice (spontaneous lupus model) were both used in the experiment. First, we observed symptoms of lupus by assessing the levels of serum anti-dsDNA antibodies and serum creatinine and renal pathology. We found that both murine models showed increased levels of serum anti-dsDNA antibodies and creatinine, enhanced glomerular fibrosis and cell infiltration, basement membrane thickening and elevated IgG deposition. After azithromycin treatment, all these medical indexes were alleviated, and kidney damage was effectively reversed. Next, macrophage polarisation was assessed in the spleen and kidneys. Macrophage infiltration in the spleen was notably decreased after azithromycin treatment in both murine models, with a remarkably elevated proportion of M2 macrophages. In addition, the expression of interleukin (IL)-1, IL-6, tumour necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS), CD86, toll-like receptor (TLR)2 and TLR4 was extremely downregulated, while the expression of transforming growth factor (TGF)-β, arginase-1 (Arg-1), chitinase-like 3 (Ym-1), found in inflammatory zone (Fizz-1) and mannose receptor (CD206) was significantly upregulated in the kidneys after azithromycin treatment. Taken together, our results indicated for the first time that azithromycin could alleviate lupus by promoting M2 polarisation in vivo. These findings exploited the newly discovered potential of azithromycin, a conventional drug with verified safety, affordability and global availability, which could be a novel treat-to-target strategy for SLE via macrophage modulation.