Mouse Model Of Lupus Nephritis Research Articles

Reversible dysregulation of renal circadian rhythm in lupus nephritis

BackgroundWe have found disruption of expression of major transcriptional regulators of circadian rhythm in the kidneys of several mouse models of lupus nephritis. Here we define the consequence of this disturbance with respect to circadian gene expression and renal homeostatic function in a mouse model of lupus nephritis.MethodsMolecular profiling of kidneys from 47 young and 41 nephritic female NZB/W F1 mice was performed at 4 hourly intervals over a 24 h period. Disruption of major circadian transcriptional regulators was confirmed by qPCR. Molecular data was normalized and analyzed for rhythmicity using RAIN analysis. Serum aldosterone and glucose and urine sodium and potassium were measured at 4 hourly intervals in pre-nephritic and nephritic mice and blood pressure was measured every 4 h. Analyses were repeated after induction of complete remission of nephritis using combination cyclophosphamide and costimulatory blockade.ResultsWe show a profound alteration of renal circadian rhythms in mice with lupus nephritis affecting multiple renal pathways. Using Cosinor analysis we identified consequent alterations of renal homeostasis and metabolism as well as blood pressure dipper status. This circadian dysregulation was partially reversed by remission induction therapy.ConclusionsOur studies indicate the role of inflammation in causing the circadian disruption and suggest that screening for loss of normal blood pressure dipping should be incorporated into LN management. The data also suggest a potential role for circadian agonists in the treatment of lupus nephritis.

Research Highlights

Research Highlights

An evaluation of a novel nanoformulation of imatinib mesylate in a mouse model of lupus nephritis.

Studies have suggested imatinib mesylate (ImM) as a potential treatment for systemic lupus erythematosus nephritis (SLEN). However, ImM has limited renal excretion. The goal of the current research was to develop an ImM containing nanoformulation, conduct studies to evaluate pharmacokinetics, and determine whether kidney deposition can be enhanced in a mouse model of SLEN. A fish oil-based ImM oil-in-water nanoemulsion was developed and characterized for particle size, zeta potential, pH, and stability. MRL/MpJ-Faslrp (model of SLEN) and MRL/MpJ (control) mice (12-13weeks) received one dose of ImM as either a nanoemulsion or naked drug. Pharmacokinetics and kidney deposition studies were performed. Statistics were conducted with a student's T-test. The nanoemulsion characteristics included particle size range of 60-80nm, zeta potential of -6.6 to -7.8mV, polydispersity index < 0.3, 3-day stability at 4°C, and limited ImM leakage from the nanoemulsion in serum. Pharmacokinetics of the nanoformulation showed changes to pharmacokinetic parameters suggesting reduced systemic exposures (with reduced potential for toxicities) to ImM. Kidney deposition of ImM was threefold higher after 4h in the MRL/MpJ-Faslrp mice that received the nanoformulation vs. naked drug. The current study showed encouraging results for development of a stable and well-characterized nanoemulsion for optimizing kidney deposition of ImM. Future strategies will define dose-efficacy and dose-toxicity relationships and evaluate approaches to further enhance kidney delivery and optimize deposition to the mesangial location of the kidney.

MiR-1968-5p is involved in the pathogenesis of lupus nephritis of NZBWF1 mice by targeting csf1.

Lupus nephritis is one of the most common and severe systemic lupus erythematosus complications. However, the pathogenesis of lupus nephritis is still poorly understood. Increasing evidence has shown that microRNAs (miRNAs) are extensively involved in the pathophysiology of autoimmune diseases. NZBWF1 is the classical mouse model of lupus nephritis. The present study aimed to investigate the expression profiling of mRNA and miRNAs of NZBWF1 mice with lupus nephritis using microarray, and explored the potential molecular mechanism of miRNA. miRNA and mRNA microarrays were performed to identify miRNA and mRNA expression changes between pre-diseased (8-week-old) NZBWF1 mice and diseased NZBWF1 mice with lupus nephritis (28-week-old). Quantitative polymerase chain reaction (qPCR) validated these results. The target of miRNA was confirmed through a dual-luciferase reporter and stimulated mesangial cells experiment. The combined miRNA and mRNA analysis identified 43 differentially expressed miRNAs and 1796 differentially expressed mRNAs between pre-disease (8-week-old) (n = 4) and diseased (28-week-old) NZBWF1 mice. We found that miR-1968-5p was significantly decreased, and csf1 mRNA was significantly increased in lupus nephritis mouse and verified by RT-PCR. csf1 has been demonstrated to play important roles in SLE. Bioinformatics analysis predicted that the csf1 was a potential target gene of miR-1968-5p. A dual-luciferase reporter assay confirmed the target binding. In cell experiments, overexpression or knockdown of miR resulted in a decrease or increase of csf1 expression, respectively. These resultssuggest that miR-1968-5p may be involved in the pathogenesis of lupus nephritis of NZBWF1 mice by targeting csf1.

Kidney macrophages in human lupus nephritis and mouse models express conserved inflammatory and remodeling gene programs and localize to the same anatomic sub-compartments.

Abstract Tissue macrophages promote kidney homeostasis through tightly regulated initiation, maintenance, and resolution of tissue repair. In lupus nephritis (LN), kidney macrophages may drive damage in glomeruli and other kidney sub-compartments leading to proteinuria and fibrosis. Recent single-cell RNA sequencing work uncovered 4 novel kidney macrophage subsets in LN patient biopsies: M2-like “reparative”, “inflammatory”, “phagocytic”, and “resident” subsets. But how macrophage gene programs translate into cellular functions driving proximal tissue damage has been difficult to study because we do not fully understand how mouse models recapitulate human LN. Here, we used single cell RNA sequencing to identify kidney macrophage subsets conserved in human and mouse models of LN. We compared the transcriptomes of macrophages collected from human LN patients at peak clinical disease to those from 4 mouse strains at early and peak clinical disease. We discovered that human “reparative”, “inflammatory”, “phagocytic” subsets were conserved across species. In particular, human “reparative” and mouse resident macrophages shared inflammatory and remodeling programs, expressed interferon stimulated genes, and localized to the same kidney sub-compartments. In nephritic mice, this subset converted to a mixed M1-inflammatory/M2-repair phenotype also observed in humans, thus identifying potential conserved programs driving tissue damage in mice and humans. These findings strongly support shared roles for conserved human and mouse macrophages. Critically, they open a new path utilizing mice to study how conserved programs translate into cellular functions driving proximal tissue damage.

Vasculature-Associated Lymphoid Tissue: A Unique Tertiary Lymphoid Tissue Correlates With Renal Lesions in Lupus Nephritis Mouse Model.

Lupus nephritis (LN) is a common complication in young patients and the most predominant cause of glomerulonephritis. Infiltrating immune cells and presence of immunocomplexes in the kidney are hallmarks of LN, which is closely associated with renal lesions (RLs). However, their regulatory mechanism in the kidney remains unclear, which is valuable for prevention of RL development. Here, we show the development of vasculature-associated lymphoid tissue (VALT) in LN, which is related to renal inflammatory cytokines, indicating that VALT is a unique tertiary lymphoid tissue. Transcriptomic analysis revealed different chemokines and costimulatory molecules for VALT induction and organization. Vascular and perivascular structures showed lymphoid tissue organization through lymphorganogenic chemokine production. Transcriptional profile and intracellular interaction also demonstrated antigen presentation, lymphocyte activity, clonal expansion, follicular, and germinal center activity in VALT. Importantly, VALT size was correlated with infiltrating immune cells in kidney and RLs, indicating its direct correlation with the development of RLs. In addition, dexamethasone administration reduced VALT size. Therefore, inhibition of VALT formation would be a novel therapeutic strategy against LN.

Complement 1q protects MRL/lpr mice against lupus nephritis via inhibiting the nuclear factor-κB pathway.

Lupus nephritis (LN) is a kidney disorder that is a critical cause of mortality in patients with systemic lupus erythematosus. The present study aimed to explore the protective role of complement component 1q (C1q) on LN and the underlying mechanism involving the nuclear factor (NF)‑κB singling pathway. MRL/lpr mice served as the LN mouse model, and pcDNA‑C1q was injected into LN mice to determine the role of C1q. C1q mRNA expression was detected using reverse transcription‑quantitative PCR. Urine protein and blood urea nitrogen (BUN) levels were measured, and the histological damage index was determined using H&E staining. ELISA was used to measure the levels of tumor necrosis factor‑α (TNF‑α), interleukin (IL)‑1β, IL‑6, anti‑C1q and anti‑double stranded DNA (dsDNA). CD68‑ and Ki67‑positivity were detected using immunofluorescence, and NF‑κB‑related protein expression was examined using western blotting. C1q mRNA expression was downregulated in renal tissues of LN mice. Overexpression of C1q decreased urine protein, BUN levels and the histological damage index in LN mice. The levels of TNF‑α, IL‑1β, IL‑6, anti‑C1q and anti‑dsDNA in renal tissues of LN mice were also reduced after pcDNA‑C1q treatment. Additionally, overexpression of C1q decreased the CD68‑ and Ki67‑positivity in glomeruli and attenuated the expression of NF‑κB‑related proteins. Phorbol 12‑myristate 13‑acetate, an NF‑κB pathway activator, reversed the inhibitory effect of C1q on inflammation, macrophage infiltration and mesangial cell (MC) proliferation in renal tissues of LN mice. Thus, it was demonstrated that C1q ameliorated inflammation and macrophage infiltration and decreased MC proliferation in renal tissues of LN mice by inhibiting the NF-κB pathway.

Emodin ameliorates renal injury in BXSB mice by modulating TNF-α/ICAM-1

The purpose of the present study was to explore the effects of emodin on renal injury in a BXSB mouse model of lupus and its mechanisms. BXSB mice were fed different concentrations of emodin (0, 5, 10 and 20 mg/kg.d), and the levels of intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor-α (TNF-α) and fibronectin (FN) levels in the glomeruli and serum levels of the anti-dsDNA antibody were determined. Mesangial cells (MCs) were cultured in vitro, and IgG-type anti-dsDNA antibody and/or emodin were added to the MC culture supernatant. In addition, TNF-α small interfering RNA (siRNA) was transfected into MCs to explore the mechanism of action of emodin. The results showed that the mice fed emodin presented decreases in the urinary protein content and glomerular TNF-α, ICAM-1 and FN levels (P<0.05). Moreover, the urine protein, TNF-α, ICAM-1 and FN levels were decreased in a dose-dependent manner (P<0.05). In vitro, the anti-dsDNA antibody group exhibited increased levels of ICAM-1 and TNF-α (P<0.05), and the anti-dsDNA antibody group showed myofibroblast-like structural changes. The aforementioned indexes were decreased in the emodin group (P<0.05), and the extent of transdifferentiation was significantly reduced. Moreover, the level of ICAM-1 decreased with the down-regulation of TNF-α (P<0.05). Emodin reduced the urine protein levels and serum levels of the anti-dsDNA antibody in a mouse model of lupus nephritis (LN). The underlying mechanism may be related to decreased levels of TNF-α, ICAM-1 and FN and the inhibition of dsDNA antibody-induced MC damage.

Efficacy of the Combination of Metformin and CTLA4Ig in the (NZB × NZW)F1 Mouse Model of Lupus Nephritis.

CTLA4Ig, a reagent that inhibits CD28 signaling, has shown therapeutic efficacy in mouse models of lupus nephritis (LN) when combined with several other biologics or standard of care drugs. Unfortunately, clinical trials treating LN patients with CTLA4Ig (abatacept) have not met endpoints. Metformin, a drug used to control hyperglycemia that inhibits mitochondrial metabolism, lowered the effective dose of glucocorticoids and prevented major flares when added on to the standard of care treatment of lupus patients with low disease activity. Metformin combined with inhibition of glycolysis by 2-deoxyglucose showed therapeutic efficacy in multiple mouse models of LN. Because CD28 signaling triggers glucose metabolism in T cells, we hypothesized that combining CTLA4Ig treatment with metformin would have the same effect. In this study, we showed that the combination of metformin and CTLA4Ig decreased the development of LN in (NZB × NZW)F1 mice treated at the early stage of disease. This preventive effect was associated with a decreased expansion of CD4+ T cell effector subsets. However, contrary to the combination with 2-deoxyglucose, metformin combined with CTLA4Ig did not alter autoantibody production, suggesting different mechanisms of symptom mitigation. Overall, this study shows therapeutic efficacy of the combination of metformin and CTLA4Ig, two drugs with established safety records, in a preclinical mouse model of LN.

Ets Family Transcription Factor Fli-1 Promotes Leukocyte Recruitment and Production of IL-17A in the MRL/Lpr Mouse Model of Lupus Nephritis.

The transcription factor Friend leukemia integration 1 (Fli-1) regulates the expression of numerous cytokines and chemokines and alters the progression of lupus nephritis in humans and in the MRL/MpJ-Faslpr (MRL/lpr) mouse model. Th17-mediated immune responses are notably important as they promote ongoing inflammation. The purpose of this study is to determine the impact of Fli-1 on expression of interleukin-17A (IL-17A) and the infiltration of immune cells into the kidney. IL-17A concentrations were measured by ELISA in sera collected from MRL/lpr Fli-1-heterozygotes (Fli-1+/−) and MRL/lpr Fli-1+/+ control littermates. Expression of IL-17A and related proinflammatory mediators was measured by real-time polymerase chain reaction (RT-PCR). Immunofluorescence staining was performed on renal tissue from MRL/lpr Fli-1+/− and control littermates using anti-CD3, anti-CD4, and anti-IL-17A antibodies to detect Th17 cells and anti-CCL20 and anti-CD11b antibodies to identify CCL20+ monocytes. The expression of IL-17A in renal tissue was significantly reduced; this was accompanied by decreases in expression of IL-6, signal transducer and activator of transcription 3 (STAT3), and IL-1β. Likewise, we detected fewer CD3+IL-17+ and CD4+IL-17+ cells in renal tissue of MLR/lpr Fli-1+/− mice and significantly fewer CCL20+CD11b+ monocytes. In conclusion, partial deletion of Fli-1 has a profound impact on IL-17A expression and on renal histopathology in the MRL/lpr mouse.

α-mangostin attenuates pristane-induced lupus nephritis by regulating Th17 differentiation.

α-mangostin, a polyphenolic xanthone derivative of mangosteen, has been reported to possess multiple therapeutic properties, such as anti-cancer, anti-allergy and anti-inflammatory activity. However, its anti-inflammatory effects in autoimmune diseases such as lupus nephritis (LN) remain unclear. In this study, we want to investigate the therapeutic effect of α-mangostin in LN. First, we elucidated the retinoic acid receptor related orphan receptor gamma t (RORγt) inhibitory activity of α-mangostin in cell-based assay and T helper 17 (Th17) differentiation in vitro assay. Then, we established a pristane-induced LN mouse model and randomly divided these into a normal control group, model control group, α-mangostin group and prednisone acetate group. Finally, anti-double-stranded DNA (anti-dsDNA) level in serum was detected by enzyme-linked immunosorbent assay, interleukin (IL)-17A and interferon (IFN)-γ expression in spleen cells by flow cytometry; histomorphology examination of kidneys was performed by periodic acid-Schiff staining and immunofluorescence analysis with an anti-immunoglobulin G (anti-IgG) and anti-IgM antibodies. We found that α-mangostin inhibited RORγt transcription activity in a cell-based assay and also polarized Th17 cells in an in vitro induction experiment. Our results also showed that α-mangostin could significantly decrease serum anti-dsDNA antibody levels, IL-17A and IFN-γ expression and alleviate renal pathological damage in the α-mangostin-treated group mice than in the model group mice. Thus, α-mangostin demonstrated its potential as a candidate therapeutic drug for LN and other Th17-mediated autoimmune diseases by inhibiting the function of Th17.

SAT-011 A negative regulatory role of Smad3 in B cell activation in lupus nephritis via the E4BP4-Mincle-Syk dependent mechanism

TGF-b signaling has been shown to play a critical role in many autoimmune diseases. However, its regulatory role in lupus nephritis remains unknown, which was investigated in the present study in a mouse model of lupus nephritis (LN) in which Smad3 gene was deficient.

Axl-mediated Akt phosphorylation leads to mTORC1 activation via NFk-B in renal mesangial cells

Abstract Proliferative glomerulonephritis (GN) is a critical condition in many forms of kidney diseases and characterized by the proliferation of mesangial cells with influx of inflammatory cells. Receptor tyrosine kinase Axl belongs to the TAM family, along with Mer and Tyro-3. Receptors from this family contribute to clearance of apoptotic cells and suppression of inflammation. Previously, we reported an important role of Axl-mediated mesangial proliferation in the anti-GBM induced mouse model of lupus nephritis. In this study, we investigated the signaling cascade induced by Axl activation in renal mesangial cells. We found that Axl activation led to the phosphorylation of mTORC1 complex, proceeded with the ribosomal protein S6 activation. Inhibition of NFκ-B activity diminished mTOR phosphorylation in mesangial cells, indicating that NFκ-B is a critical regulator for mTORC1 activation in the Axl/Akt pathway. Axl expression also participated in mesangial cell efferocytosis. Interestingly, mesangial efferocytosis is not mediated by Mer receptor tyrosine kinase, the canonical TAM family receptor facilitating apoptotic cell engulfment in macrophages. Taken together, data suggest that Axl mediated mTOR activation and apoptotic cell engulfment is renal mesangial cell specific, as those functions were not observed in similarly treated peritoneal macrophages.

Glomerular Proteomic Profiles in the NZB/W F1 Hybrid Mouse Model of Lupus Nephritis.

BackgroundLupus nephritis is one of the most serious complications of systemic lupus erythematosus (SLE) and is associated with patient mortality. This study aimed to investigate the proteomic profiles of the glomerulus in the NZB/W F1 hybrid mouse model of mild and severe lupus nephritis using two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) combined with matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF-MS).Material/MethodsFemale NZB/WF1 mice (n=60) at 28 weeks of age were divided into the mild proteinuria group (+1), the moderate proteinuria group (+2), and the severe proteinuria group (+3) using paper strip urine testing, and then later divided into a mild (≤1+) and severe (≥3+) proteinuria group to allow comparison of upregulation and down-regulation of proteins between the two groups. Renal glomeruli were isolated following renal perfusion with magnetic beads. Protein expression was determined by Western blot, immunohistochemistry, 2D-DIGE, and MALDI-TOF-MS.ResultsA total of 56 differentially expressed proteins were identified from 133 protein spots, of which 18 were upregulated and 23 were down-regulated between groups 1 and 2. Expression of the proteins Ras-related GTP-binding protein B (RRAGB), serine/threonine-protein kinase 1 (SMG1), angiopoietin 2 (ANGP2), methylmalonate semialdehyde (MMSA), and ATP beta chain (ATPB) were identified by Western blot and SMG1, ANGP2, and MMSA were identified by immunohistochemistry.ConclusionsIn a mouse model of lupus nephritis, expression of SMG1, MMSA, and ATPB were down-regulated, and RRAGB and ANGP2 were upregulated.

Xenogeneic Transplantation of Human Placenta-Derived Mesenchymal Stem Cells Alleviates Renal Injury and Reduces Inflammation in a Mouse Model of Lupus Nephritis.

Human placenta-derived mesenchymal stem cells (pMSCs) are considered a good source for cell therapy. The purpose of this study was to observe whether the transplantation of human pMSCs would affect the treatment of lupus nephritis (LN)-prone MRL/lpr mice. Multiple injections (at the 16th, 18th, and 20th week of age) of 1 × 106 pMSCs were administered. Urine was collected to evaluate proteinuria and urine creatinine levels. Blood was collected for the measurement of serum antinuclear antibody (ANA) and anti-double-stranded DNA (dsDNA) antibody levels. Renal tissues were collected for histological staining and examination by light and electron microscopy quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western Blot. The results confirmed that pMSC treatment reduced the severity of 24-h proteinuria, decreased the production of anti-dsDNA antibodies, and ameliorated renal pathological changes in MRL/lpr mice. Furthermore, pMSCs reduced renal inflammation by inhibiting the expression of nuclear factor kappa B (NF-κB) and then downregulating the expression of tumor necrosis factor-α (TNF-α), intercellular cell adhesion molecule-1 (ICAM-1), and plasminogen activator inhibitor-1 (PAI-1). Therefore, our present study demonstrated a protective effect of pMSCs against renal injury and inflammation in MRL/lpr mice.

A20 overexpression exerts protective effects on podocyte injury in lupus nephritis by downregulating UCH-L1.

Lupus nephritis (LN), an autoimmune kidney disease caused by systemic lupus erythematosus (SLE), is the inflammation of the kidney. Although the treatment of LN is still a therapeutic challenge for many practitioners, the present study aims to provide a new insight for the treatment and management. The study aims to explore the effect of A20 on LN in relation to the nuclear factor-kappa B (NF-κB) signaling pathway. MRL/lpr mice were used as the LN mouse model. Next, A20, UCH-L1, and NF-κB expression in LN patients and MRL/lpr mice was determined. A20 was upregulated in podocytes to assess biological functions of A20 in LN. Furthermore, to further investigate the pivotal role of the NF-κB pathway in LN, the NF-κB pathway was blocked in podocytes. Next, UCH-L1 was downregulated in MRL/lpr mice to assess biological functions of UCH-L1 in LN. A20 was downregulated, whereas UCH-L1 was upregulated in LN. Overexpressed A20 declined NF-κB, UCH-L1 expression, and the extent of p65 phosphorylation. A20 overexpression or UCH-L1 inhibition increased expression of synaptoporin and nephrin but decreased desmin expression and ubiquitin accumulation level in podocytes. Moreover, A20 overexpression or UCH-L1 inhibition increased the podocyte number but decreased protein level of cleaved caspase-3, podocyte lesion improvement, decreased foot process width, glomerulus basement membrane, and foot process fusion rate. In addition, urine protein, blood urea nitrogen, serum creatinine, and ds-DNA antibody levels decreased with elevated A20 or depleted UCH-L1. Collectively, it could be concluded that A20 protects against podocyte injury in LN via UCH-L1 by inactivating the NF-κB signaling pathway.

Accelerated Glomerular Cell Senescence in Experimental Lupus Nephritis.

BackgroundThe aim of this study was to determine whether senescence in renal glomeruli is involved in lupus nephritis (LN); the expression of senescence-associated β-galactosidase (SA-β-Gal) and its association with glomerular lesions were investigated in a mouse model of LN.Material/MethodsEighteen MRL/lpr mice with severe proteinuria were randomly divided into 2 equal groups and intraperitoneally injected with dexamethasone (DEX) or saline; 4 age-matched mice with mild proteinuria served as controls. Serum creatinine and urinary protein levels were analyzed, and kidney histological changes were observed by periodic acid–Schiff and Sirius Red staining. SA-β-Gal was detected via histochemistry. Glomerular expression of collagen IV, α-SMA, and nephrin was analyzed by immunohistochemistry, and glomerular complement C3 deposition was tested by immunofluorescence. The relationships between SA-β-Gal expression and renal function or glomerular lesion markers were determined by Spearman’s correlation analysis.ResultsMice with severe proteinuria exhibited glomerular segmental sclerosis and endothelial cell proliferation. DEX administration suppressed these lesions but had no significant effect on 24-hour urinary protein levels. The elevated glomerular expression of SA-β-Gal in proteinuric mice was attenuated by DEX treatment. In addition, DEX treatment markedly downregulated glomerular C3 deposition and collagen IV and α-SMA expression, while significantly increasing nephrin expression. Furthermore, SA-β-Gal expression was positively correlated with urinary protein levels and expression of α-SMA.ConclusionsAccelerated senescence of glomerular cells may contribute to glomerular injury in LN.

S3I-201 ameliorates tubulointerstitial lesion of the kidneys in MRL/lpr mice

It is high incidence of tubulointerstitial lesion (TIL) in lupus nephritis (LN) and TIL can affect the prognosis of patients with LN. Signal transducer and activator of transcription (STAT) 3 was activated in LN and STAT3 inhibition could delay the onset of LN. Here, we evaluated the role of a well-known STAT3 inhibitor, S3I-201, on TIL in lupus nephritis. STAT3 was activated in MRL/lpr mice (a mouse model of lupus nephritis), and treatment with S3I-201 inhibited the activation of it. The level of 24-h urine protein and nitrogen urea increased in MRL/lpr mice and adminstration of S3I-201 reduced the level of urinary protein. In addition, S3I-201 attenuated the expression of α-smooth muscle actin (α-SMA), Fibronectin (FN) proteins, as well as the expression of monocyte chemotactic factor-1 (MCP-1) and intercellular adhesion molecule (ICAM-1). However, the expression of E-cadherin improved when treatment with S3I-201. These results revealed that the activation of STAT3 mediates tubulointerstitial lesion in mice with LN. S3I-201, by suppressing STAT3 activity, has therapeutic effect in lupus nephritis.

Protective effects of quercetin treatment in a pristane-induced mouse model of lupus nephritis

Introduction: Lupus nephritis (LN) is one of the most severe complications of systemic lupus erythematosus. As murine models of LN are valuable tools to better understand its pathophysiology and to search for new effective treatments, we investigated the effects of the bioflavonoid quercetin on pristane-induced LN mice through histomorphological analyses.Methods: Immunofluorescence and biochemical assays were used to evaluate the expression of markers of inflammation (interleukin-6, IL-6; tumour necrosis factor-α, TNF-α), oxidative stress (catalase, CAT; superoxide dismutase 1, SOD1; thiobarbituric acid reactive substances, TBARS), apoptosis (Bax), and fibrosis (transforming growth factor-β1, TGF-β1). Glomerular and tubular ultrastructure was analysed, and tissue messenger RNA of podocin, podoplanin and α3β1-integrin were quantified using the real-time polymerase chain reaction.Results: Pristane-induced LN mice showed severe kidney injury, characterized by increased proteinuria, glomerular mesangial expansion and inflammation, high expression of the pro-fibrotic, apoptotic and prooxidant markers and reduction of antioxidants. In the kidney ultrastructure, foot process (FP) effacement, apoptotic mesangial cells and abnormal mitochondria with disrupted cristae were observed, along with suppressed tissue mRNA of podocin, podoplanin and α3β1-integrin. Treatment with quercetin in the pristane-induced LN mice model was nephroprotective, decreasing proteinuria levels and significantly lowering tissue expression of IL-6, TNF-α, TGF-β1, Bax and TBARS. Simultaneously, quercetin significantly increased CAT and SOD1 expressions in these mice. In addition, it was observed improvement of the kidney ultrastructure, and tissue mRNA of podocin, but not podoplanin and α3β1-integrin, was restored to the levels found in the control mice.Conclusion: In conclusion, these findings provide experimental evidence of the renoprotective effects of quercetin in the pristane-induced LN mice model. We suggest that quercetin effectively ameliorates the kidney damage caused by pristane, a bioflavonoid to be further evaluated as a new therapeutic strategy in this disease.

Immunosuppressive effects of hydroxychloroquine and artemisinin combination therapy via the nuclear factor-κB signaling pathway in lupus nephritis mice.

Lupus nephritis (LN) is one of the most common and severe manifestations of systemic lupus erythematosus, leading to permanent renal damage and chronic kidney disease. Hydroxychloroquine (HCQ) serves a protective role against lupus-associated clinical manifestations and medical complications; however, it results in numerous adverse reactions, limiting its long-term use. The aim of the present study was to investigate the combined effect of HCQ and artemisinin (ART) on LN, and to elucidate the underlying mechanisms. An in vivo LN mouse model was prepared, and the animals were administered prednisone (PDS; serving as a positive control), high-dose HCQ (H-HCQ) or low-dose HCQ combined with ART (L-HCQ + ART) once daily for 8 weeks. The body weight, serum biochemical parameters, immune and inflammatory indicators, renal and spleen histological alterations, and mRNA expression levels of Kruppel-like factor 15 (KLF15) and nuclear factor-κB (NF-κB) were analyzed. It was observed that L-HCQ + ART and H-HCQ ameliorated the LN-induced body weight decrease, and significantly decreased the levels of anti-double stranded DNA, antinuclear antibodies, immunoglobulin G, interferon γ, tumor necrosis factor-α and transforming growth factor-β1, as well as improved the kidney and spleen pathology, when compared with the model group. In addition, L-HCQ + ART and H-HCQ treatments induced KLF15 upregulation and NF-κB downregulation. These results indicated that treatment with L-HCQ + ART exerted renoprotective effects by regulating the expression levels of cytokines, KLF15 and NF-κB. This combination treatment may have a similar immunosuppressive effect as PDS and H-HCQ, and may be a promising alternative for LN treatment.