Lupus Nephritis In Mice Research Articles

Gbp3 is associated with the progression of lupus nephritis by regulating cell proliferation, inflammation and pyroptosis

Lupus nephritis (LN) is a major cause death in patients with systemic lupus erythematosus. We aimed to find the differentially expressed genes (DEGs) in LN and confirm the regulatory mechanism on LN. The mouse model of LN was constructed by subcutaneous injection of pristane. RNA-seq screened 392 up-regulated and 447 down-regulated DEGs in LN mouse model, and KEGG analysis found that the top 20 DEGs were enriched in arachidonic acid metabolism, tryptophan metabolism, etc. The hub genes, Kynu, Spidr, Gbp3, Cbr1, Cyp4b1, and Cndp2 were identified, in which Gbp3 was selected for following study. Afterwards, the function of Gbp3 on the proliferation, inflammation, and pyroptosis of LN was verified by CCK-8, ELISA, and WB in vitro. The results demonstrated that si-Gbp3 promoted cell proliferation and inhibited the levels of inflammatory factors (IL-1β, TNF-α and IL-8) and pyroptosis-related proteins (GSDMD, Caspase-1 and NLRP3) in a cell model of LN. In constrast, Gbp3 overexpression played an opposite role. In summary, Gbp3 promoted the progression of LN via inhibiting cell proliferation and facilitating inflammation and pyroptosis.

C/EBPβ isoform-specific regulation of podocyte pyroptosis in lupus nephritis-induced renal injury.

As an essential factor in the prognosis of systemic lupus erythematosus (SLE), lupus nephritis (LN) can accelerate the rate at which patients with SLE can transition to chronic kidney disease or even end-stage renal disease. Podocytes now appear to be a possible direct target in LN in addition to being prone to collateral damage from glomerular capillary lesions induces by immune complexes and inflammatory processes. The NLRP3 inflammasome is regulated by CCAAT/enhancer-binding protein β (C/EBPβ), which is involved in the pathogenesis of SLE. However, the role and mechanism of C/EBPβ in LN remain unclear. In this investigation, glomerular podocytes treated with LN serum and MRL/lpr mice were employed as in vivo and in vitro models of LN, respectively. In vivo, the expression of C/EBPβ isoforms was detected in kidney specimens of humans and mice with LN. Then we assessed the effect of C/EBPβ inhibition on renal structure and function by injecting RNAi adeno-associated virus of C/EBPβ shRNA into MRL/lpr mice. In vitro, glomerular podocytes were treated with LN serum and C/EBPβ siRNA to explore the role of C/EBPβ in the activation of the AIM2 inflammasome and podocyte injury. C/EBPβ-LAP and C/EBPβ-LIP were significantly overexpressed in kidney tissue samples from LN patients and mice, and C/EBPβ inhibition significantly alleviated renal function damage and ameliorated renal structural deficiencies. Inflammatory pathways downstream from the AIM2 inflammasome could be suppressed by C/EBPβ knockdown. Furthermore, the upregulation of C/EBPβ-LAP could activate the AIM2 inflammasome and podocyte pyroptosis by binding to the promoters of AIM2 and CASPASE1 to enhance their expression, and the knockdown of AIM2 or (and) caspase-1 reversed the effects of C/EBPβ-LAP overexpression. Interestingly, C/EBPβ-LIP overexpression could transcriptionally inhibit IRAG and promote Ca2+ release-mediated activation of the AIM2 inflammasome. This finding suggests that C/EBPβ is not only involved in the regulation of the expression of key proteins of the AIM2 inflammasome but also affects the polymerization of key proteins of the AIM2 inflammasome through the regulation of Ca2+ release. In conclusion, this study provides a new idea for studying the regulatory mechanism of C/EBPβ and provides a theoretical basis for the early diagnosis and treatment of LN in the future. © 2023 The Pathological Society of Great Britain and Ireland.

Lactobacillus plantarum CQPC02 intervenes in mouse lupus nephritis by regulating the NF-κB signaling pathway.

A strain of Lactobacillus plantarum CQPC02 (LP-CQPC02) isolated from naturally fermented kimchi was utilized in this investigation. In order to construct an animal model of lupus nephritis, pristane was used. We then used a kit to identify markers in mouse blood and tissues and a quantitative polymerase chain reaction (qPCR) to measure the expression of genes associated to nuclear factor kappa-B (NF-κB) in mouse kidney tissue. According to the results of the experiments, oral administration of LP-CQPC02 LP-CQPC02 may lessen the lupus nephritis-related rise in urine protein as well as the cytokine levels that were rising in the serum and renal tissues, including IL-6, IL-12, tumor necrosis factor alpha, and interferon. Additionally, in mice with nephritis, LP-CQPC02 can lower serum creatinine (SCr), blood urea nitrogen (BUN), total cholesterol (TC), triglyceride (TG), and raise total protein (TP) and albumin (ALB) levels. In mice with nephritis, LP-CQPC02 can also reduce the positive rate of double-stranded deoxyribonucleic acid (dsDNA). Pathological sections were examined, and it was shown that LP-CQPC02 can lessen tissue damage such incomplete glomerular morphology and inflammatory infiltration brought on by nephritis. In the kidneys of mice with lupus nephritis, LP-CQPC02 can upregulate the expression of inhibitor of NF-κB (IκB-α), downregulate the expression of NF-κB, transforming growth factor-β1 (TGF-β1), vascular endothelial growth factor (VEGF), intercellular cell adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1). Lactobacillus plantarum CQPC02 has been confirmed to have an intervention effect on nephritis in mice and has the potential as a probiotic.

Knockdown of DEC2 expression inhibits the proliferation of mesangial cells through suppressed glycolysis and p38 MAPK/Erk pathway in lupus nephritis

BackgroundTo elucidate the mechanism by which DEC2 modulates the proliferation of mesangial cells (MCs) in lupus nephritis (LN).MethodsThe 32-week-old female Fcgr2b−/− mice and their serum-treated MCs were used as in vivo and in vitro LN model. MCs knocked down of DEC2 and overexpressed with DEC2 were also established. The expression of DEC2 was measured in the kidneys of Fcgr2b−/− mice and LN serum-treated MCs using RT-qPCR and Western blot. MCs proliferation was detected by 5-ethynyl-2′-deoxyuridine (EdU) labeling assay and PCNA expression using immunofluorescence. The glucose metabolism was evaluated in LN serum-treated MCs, and the levels of lactate production, glucose consumption, ATP production and mitochondrial membrane potential were assayed. The glycolysis and mitochondrial respiration function of the MCs were measured using the Extracellular Flux Analyzer. The extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) were dynamically monitored and multiple important bioenergetic parameters can be calculated. The expression of Toll like receptor 4 (TLR4) and glucose transporter 1 (GLUT1) were detected in the MCs. Multiple signaling proteins were screened.ResultsDEC2 was found overexpressed in the kidney of Fcgr2b−/− LN mice. Knockdown of DEC2 inhibited LN serum-induced MCs proliferation. DEC2 was associated with the glucose metabolism in LN serum-treated MCs. DEC2 regulated glycolysis in LN serum-treated MCs. DEC2 was associated with mitochondrial fitness in LN serum treated MCs. DEC2 activated MCs glycolysis through TLR4 and glucose transporter 1 (GLUT1) regulation. DEC2 regulated MCs proliferation through two signaling pathways including dependent and independent of glycolysis, which located in the downstream of TLR4 signaling.ConclusionKnockdown of DEC2 expression inhibits the proliferation of MCs through suppressed glycolysis and p38 MAPK/ERK pathway in LN.

DUSP2 inhibits the progression of lupus nephritis in mice by regulating the STAT3 pathway.

One of the most severe side effects of systemic lupus erythematosus (SLE) is lupus nephritis (LN). To search for potential therapeutic targets in SLE is crucial for the progression of SLE. In this study, we selected C57BL/6J mice as controls and MRL/lpr mice as an LN model and obtained dual specificity phosphatase 2 (DUSP2)-overexpressed mice by injecting AAV-DUSP2 plasmid into the tail vein. Then, proteinuria, urea nitrogen, dsDNA and TNF-α, IL-6, and IL-1β levels were measured in each group of mice. In addition, renal histopathological damage was assessed by hematoxylin-eosin. Finally, STAT3 phosphorylation levels were detected by Western blot assay. The results showed that DUSP2 could reduce proteinuria, urea nitrogen, dsDNA and TNF-α, IL-6, and IL-1β levels and improve renal tissue injury in mice with LN. Mechanistically, DUSP2 inhibited STAT3 phosphorylation. These results demonstrated that DUSP2 played a role in ameliorating LN, which provided potential targets for LN research.

The Effect of Snail Mucus (Achatina Fulica) on The Degree of Kidney Interstitial Fibrosis In Lupus Nephritis Mice Model

<p class="AbstractNormal"><strong>Introduction</strong><strong><span lang="EN-US">:</span></strong><strong></strong><span lang="IN">cytotoxic drugs dominate SLE therapy, so new therapies with minimum side effects are needed. Snail (Achatina Fulica) mucus contains two types of protein; heparan and acharan sulfate. The snail mucus has significant potential benefits, but its use in lupus nephritis has never been examined.</span></p><p class="AbstractNormal"><strong>Methods</strong><strong><span lang="EN-US">:</span></strong><strong></strong><span lang="IN">This research used an experimental model. It used mice for the experiment. The mice were divided into five groups: control, untreated lupus, standard therapy (methylprednisolone), snail mucus therapy, and a combination of standard therapy and snail mucus. Renal histology was examined at the end of the fifth month. Data were analyzed using the Shapiro-Wilk, ANOVA, and Tukey Post Hoc tests.</span></p><p class="AbstractNormal"><strong>Result</strong><strong><span lang="EN-US">s: </span></strong><span lang="EN-US">The level of interstitial fibrosis between the standard therapy group and the snail mucus group showed an MD value of -0.13 with a p-value of 1.00, meaning there is no significant difference between the level of interstitial fibrosis in the two groups. The comparison between the standard therapy group and the combination of the standard therapy group showed an MD value of 0.64 with a p-value of 0.992, which means that the combination of standard therapy tends to decrease the level of interstitial fibrosis. </span><strong><span lang="EN-US"> </span></strong></p><p class="AbstractNormal"><strong>Conclusion</strong><strong><span lang="EN-US">: </span></strong><span lang="EN-US">The administration of snail mucus in combination with standard therapy affects the decrease in the level of interstitial fibrosis in mice model lupus.</span></p>

Brensocatib, an oral, reversible inhibitor of dipeptidyl peptidase 1, mitigates interferon-α-accelerated lupus nephritis in mice.

Neutrophils have been implicated in initiating and perpetuating systemic lupus erythematosus and the resultant kidney damage in lupus nephritis (LN) patients, in part through an excessive release of neutrophil serine proteases (NSPs). NSP zymogens are activated by dipeptidyl peptidase 1 (DPP1) during neutrophil maturation and released by mature neutrophils in response to inflammatory stimuli. Thus, a potential strategy to attenuate disease progression in LN would be to inhibit DPP1. We tested whether brensocatib, a highly selective and reversible DPP1 inhibitor, could mitigate LN progression in an interferon-alpha (IFNα)-accelerated NZB/W F1 mouse model. To confirm brensocatib's pharmacodynamic effect on NSPs in this mouse strain, repeated dose studies were conducted for 7 and 14 days in naïve NZB/W F1 mice via oral gavage twice a day. Brensocatib at 2 and 20 mg/kg/day achieved a significant reduction in bone marrow NSP activities after 7 days of daily administration. To initiate LN disease progression, the mice were injected with an IFNα-expressing adenovirus. After 2 weeks, three brensocatib doses (or vehicle) were administered for 6 more weeks. Throughout the 8-week study, brensocatib treatment (20 mg/kg/day) significantly reduced the occurrence of severe proteinuria compared to the vehicle control. Brensocatib treatment also entailed a significant reduction in the urine albumin-to-creatinine ratio, indicating decreased kidney damage, as well as a significant reduction in blood urea nitrogen level, suggesting improved renal function. Based on kidney histopathology analysis, brensocatib treatment significantly lowered both the renal tubular protein score and the nephropathy score compared to the vehicle group. A trend towards reduced glomerulonephritis score with brensocatib treatment was also observed. Lastly, brensocatib significantly reduced LN mouse kidney infiltration by various inflammatory cells. In conclusion, these results suggest that brensocatib alters disease progression in LN mice and warrant further evaluation of DPP1 inhibition in LN.

The Effect of Snail Mucus (Achatina Fulica) Toward The Activity and Chronicity Indices of Renal Histology in Pristane-Induced Lupus Nephritis Mice Model

Background: Snail mucus (Achatina Fulica) has been known to contain heparan sulfate, and acharan sulfate, a glycosaminoglycan with anti-inflammatory properties and might repair the injured glomeruli. Aim: This study aims to find the effect of snail mucus on activity and chronicity indices of renal histology in a pristane-induced lupus nephritis mice model. Method: This was an experimental study with a post-test-only control group design using 42 mice strains Balb/C. Mice were randomized into six groups: control, lupus nephritis, methylprednisolone, snail mucus 0.5 ccs, snail mucus 0,5 cc and methylprednisolone, and snail mucus one cc and methylprednisolone group. Result: Snail mucus significantly affected the activity index (p = 0.001). The lowest activity index was shown by snail mucus one cc and methylprednisolone group. While the chronicity index was not significantly affected by the snail mucus with p = 0.195. Snail mucus decreases the activity index of renal histology in the pristane-induced lupus nephritis mice model but not the chronicity index. Bangladesh Journal of Medical Science Vol. 22 No. 03 July’23 Page : 515-520

Cordyceps proteins alleviate lupus nephritis through modulation of the STAT3/mTOR/NF-кB signaling pathway.

Cordyceps is a parasitic edible fungus, which is a unique Chinese medicinal material. It has been reported to have immunomodulatory effects and use in kidney disease. Especially, Cordyceps has been used in the treatment of lupus nephritis (LN). Cordyceps proteins (CP) have a favorable bidirectional immunomodulatory functions and may have therapeutic potential for LN. However, the underlying molecular mechanism remains unknown. So this study aimed to examine the activities of CP in LN and possible mechanism. So proteomics was performed to detect proteins components of Cordyceps, and analysis it. In addition, MRL/lpr mice were used to study the progression of LN. The MRL/lpr mice were fed either CP (i.g, 0.5, 1.0, 1.5g/kg/d), prednisolone acetate (PA, i.g, 6mg/kg/d), or Bailing capsule (BC, i.g, 0.75g/kg/d) for 8 weeks. Hematoxylin-eosin (H&E), Periodic Acid Schif (PAS) and Masson's stainings, Immunofluorescence, and Immunohistochemistry were performed to verify the therapeutic effect of CP on MRL/lpr mice. The mechanism by CP alimerated LN was uncovered by Western blotting (WB) and Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) methods. Our results revealed that CP blocked proteinuria production and renal inflammatory infiltratation in MRL/lpr mice to reduce the renal fibrosis. In addition, CP worked better than BC which is artificial Cordyceps fungus powder in regulating proteinuria to urine creatinine ratio and interleukin-4(IL-4) protein amount. Especially, CP modulated the STAT3/mTOR/NF-кB signaling pathway in LN mice and brought a more pronounced lowering effect on the contents of IL-6 and IL-1β than the PA. CP could be a potential anti-inflammatory immune product with strong regulatory effects and potency than BC and PA in nephritis therapeutics.

Povetacicept, an Enhanced Dual APRIL/BAFF Antagonist That Modulates B Lymphocytes and Pathogenic Autoantibodies for the Treatment of Lupus and Other B Cell-Related Autoimmune Diseases.

Dysregulated APRIL/BAFF signaling is implicated in the pathogenesis of multiple autoimmune diseases, including systemic lupus erythematosus and lupus nephritis. We undertook this study to develop and evaluate a high-affinity APRIL/BAFF antagonist to overcome the clinical limitations of existing B cell inhibitors. A variant of TACI-Fc generated by directed evolution showed enhanced binding for both APRIL and BAFF and was designated povetacicept (ALPN-303). Povetacicept was compared to wild-type (WT) TACI-Fc and related molecules in vitro and in vivo. Povetacicept inhibited APRIL and BAFF more effectively than all evaluated forms of WT TACI-Fc and selective APRIL and BAFF inhibitors in cell-based reporter assays and primary human B cell assays, mediating potent suppression of B cell proliferation, differentiation, and immunoglobulin (Ig) secretion. In mouse immunization models, povetacicept significantly reduced serum immunoglobulin titers and antibody-secreting cells more effectively than anti-CD20 monoclonal antibodies, WT TACI-Fc, or APRIL and BAFF inhibitors. In the NZB × NZW mouse lupus nephritis model, povetacicept significantly enhanced survival and suppressed proteinuria, anti-double-stranded DNA antibody titers, blood urea nitrogen, glomerulonephritis, and renal immunoglobulin deposition. In the bm12 mouse lupus model, povetacicept significantly reduced splenic plasmablasts, follicular helper T cells, and germinal center B cells. In non-human primates, povetacicept was well tolerated, exhibited high serum exposure, and significantly decreased serum IgM, IgA, and IgG levels after a single dose. Enhanced APRIL and BAFF inhibition by povetacicept led to greater inhibition of B cell populations critical for autoantibody production compared to WT TACI-Fc and CD20-, APRIL-, or BAFF-selective inhibitors. Potent, dual inhibition by povetacicept has the potential to significantly improve clinical outcomes in autoantibody-related autoimmune diseases.

Rapamycin Treatment Alleviates Chronic GVHD-Induced Lupus Nephritis in Mice by Recovering IL-2 Production and Regulatory T Cells While Inhibiting Effector T Cells Activation

In this study, we test the therapeutic effects of rapamycin in a murine model of SLE-like experimental lupus nephritis induced by chronic graft-versus-host disease (cGVHD). Our results suggest that rapamycin treatment reduced autoantibody production, inhibited T lymphocyte and subsequent B cell activation, and reduced inflammatory cytokine and chemokine production, thereby protecting renal function and alleviating histological lupus nephritis by reducing the occurrence of albuminuria. To explore the potential mechanism of rapamycin's reduction of kidney damage in mice with lupus nephritis, a series of functional assays were conducted. As expected, rapamycin remarkably inhibited the lymphocytes' proliferation within the morbid mice. Interestingly, significantly increased proportions of peripheral CD4+FOXP3+ and CD4+CD25high T cells were observed in rapamycin-treated group animals, suggesting an up-regulation of regulatory T cells (Tregs) in the periphery by rapamycin treatment. Furthermore, consistent with the results regarding changes in mRNA abundance in kidney by real-time PCR analysis, intracellular cytokine staining demonstrated that rapamycin treatment remarkably diminished the secretion of Th1 and Th2 cytokines, including IFN-γ, IL-4 and IL-10, in splenocytes of the morbid mice. However, the production of IL-2 from splenocytes in rapamycin-treated mice was significantly higher than in the cells from control group animals. These findings suggest that rapamycin treatment might alleviate systemic lupus erythematosus (SLE)-like experimental lupus nephritis through the recovery of IL-2 production, which promotes the expansion of regulatory T cells while inhibiting effector T cell activation. Our studies demonstrated that, unlike other commonly used immunosuppressants, rapamycin does not appear to interfere with tolerance induction but permits the expansion and suppressive function of Tregs in vivo.

Lupus Recipe inhibits cGVHD-induced lupus nephritis in mice and promote renal LC3-associated autophagy.

Lupus nephritis (LN) is one of the most severe manifestations of systemic lupus erythematosus (SLE). The chronic graft versus host disease (cGVHD) mouse model is a well-established model of SLE. LC3-associated autophagy plays a critical role in extracellular particle clearance, including pathogens and apoptotic cells. Lupus Recipe (LR) is a Chinese herbal compound that has been proven to be effective in treating SLE. In the study, we investigated the protective effects of LR or LR combined with prednisone on cGVHD mouse model and LC3-associated autophagy in the kidney. The mice were subjected to six groups. The LR treatment group received LR at the dosage of 1.15 and 2.3 g/kg/day, respectively. The corticosteroid treatment group received prednisone at a dosage of 5 mg/kg/day. The combination treatment group received LR at a dosage of 2.3 g/kg/day, and prednisone at 2.5 mg/kg/day. LR treatment reduced proteinuria and serum triglyceride levels, as well as spleen weight. LR also alleviated pathologic damage and immunoglobulin G deposition in the kidney. LR combined with a low dose of prednisone significantly improved kidney function and decreased serum triglyceride, total cholesterol, and spleen weight. In addition, combination treatment relieved kidney injury more effectively than LR alone. Western blot revealed that LR treatment or LR combined with prednisone increased the LC3-associated autophagy protein of Rubicon and Nox2, as well as LC3I levels in the kidney tissues. In conclusion, LR inhibited the manifestation of cGVHD-induced LN, which may attribute to the increased levels of LC3-associated autophagy.

Hyperbaric Oxygen Ameliorates The Expression of Tumor Growth Factor-β and Malondialdehyde in Pristane-induced Lupus Nephritis Mice Model

BACKGROUND: Lupus nephritis (LN) is associated with chronic renal failure and a high mortality rate. Tumor growth factor-β (TGF-β) plays a basic part in keeping up immune homeostasis, meanwhile extensive oxidation of the lipid membrane in LN causes the arrangement of malondialdehyde (MDA). Up to date, the mechanism of hyperbaric oxygen (HBO) therapy in LN has not been elucidated well. Hence this study was conducted to assess the impact of HBO therapy on TGF-β and MDA expression in the pristane-induced LN mice model.METHODS: Thirty-two mice aged 8-12 old weeks were isolated into 4 groups: normal saline-injected mice (group 1); pristane-injected mice (group 2); as well as pristane-injected followed by HBO-exposured with 2.4 (group 3) and 1.5 (group 4) atmosphere absolute (ATA) pressure. Pristane were injected intraperitoneal to initiate LN. Two months after pristane injection, the mice were placed within 24 hours in the special cage for metabolic examination to determined that pristane-induced LN mice model was successfully formed and marked by the occurring proteinuria. Oxidative stress was assessed by examining MDA, while systemic inflammation was assessed by examining by TGF-β. MDA and TGF-β serum were measured by enzyme-linked immunosorbent assay (ELISA).RESULTS: A significantly lower (p<0.050) MDA expression was found in group 3 in comparison with group 2. The results also showed that TGF-β level was significantly increased (p<0.050) in group 3 compared to group 2.CONCLUSION: HBO therapy ameliorates inflammation in LN by diminishing MDA and expanding TGF-β levels through activating antioxidants.KEYWORDS: lupus nephritis, hyperbaric oxygen, malondialdehyde, tumor growth factor-β

TRAF3 plays a role in lupus nephritis by regulating Th17 cell and Treg cell balance as well as NF-κB signaling pathway in mice

Lupus nephritis (LN) occurs with inflammatory lesion in patients suffering from systemic lupus erythematosus (SLE). Tumor necrosis factor (TNF) receptor associated factor 3 (TRAF3) is an important mediator in inflammation. To explore the roles of TRAF3 in LN, the LN mouse model was firstly established with intraperitoneal (i.p.) injection of pristine. Our results found that the amount of urinary protein was increased evidently at day 28, and renal damage occurred in the LN mouse model, but the TRAF3 knockdown reduced the urinary protein and alleviated the inflammatory lesion. The proinflammatory cytokines TNF-α, IL-1β, IL-17a, IFN-γ and IgM, IgG antibody were enriched, but there was little amount of IL-10 in the LN mouse model. Moreover, the amount of CD40+ B cells, CD4+ T cells sub-type, Th17 cells were abundant, and the proteins TRAF3, TRAF2, NF-κBp52, IKKα, ICAM1 in the kidney were highly expressed in the LN mouse model. However, TRAF3 knockdown enhanced the production of IL-10 and reduced the amount of pro-inflammatory cytokines, immunoglobulin, and the protein expressions of TRAF3, TRAF2, NF-κBp52, IKKα, ICAM1. In conclusion, TRAF3 plays a role in LN by regulating Th17 cell and Treg cell balance as well as NF-κB signaling pathway in mice.

Kidney tubular epithelial cell ferroptosis links glomerular injury to tubulointerstitial pathology in lupus nephritis

Ferroptosis is a druggable, iron-dependent form of cell death that is characterized by lipid peroxidation but has received little attention in lupus nephritis. Kidneys of lupus nephritis patients and mice showed increased lipid peroxidation mainly in the tubular segments and an increase in Acyl-CoA synthetase long-chain family member 4, a pro-ferroptosis enzyme. Nephritic mice had an attenuated expression of SLC7A11, a cystine importer, an impaired glutathione synthesis pathway, and low expression of glutathione peroxidase 4, a ferroptosis inhibitor. Lipidomics of nephritic kidneys confirmed ferroptosis. Using nephrotoxic serum, we induced immune complex glomerulonephritis in congenic mice and demonstrate that impaired iron sequestration within the proximal tubules exacerbates ferroptosis. Lupus nephritis patient serum rendered human proximal tubular cells susceptibility to ferroptosis which was inhibited by Liproxstatin-2, a novel ferroptosis inhibitor. Collectively, our findings identify intra-renal ferroptosis as a pathological feature and contributor to tubular injury in human and murine lupus nephritis.

DNA Nanoflowers' Amelioration of Lupus Symptoms in Mice via Blockade of TLR7/9's Signal.

Inhibitory oligodeoxynucleotides (INH-ODN) can exert an immunomodulatory effect to specifically block TLR7 and TLR9 signaling in systemic lupus erythematosus (SLE). To extend the half-life of INH-ODN in vivo, the phosphorothioate backbone, instead of the native phosphodiester, is preferred due to its strong resistance against nuclease degradation. However, its incomplete degradation in vivo may lead to potential risk. To solve these problems and enhance the blockage of TLR7 and TLR9, we prepared highly compressed DNA nanoflowers with prolonged native DNA backbones and repeated INH-ODN motifs. Three therapeutic types of nanoflower, incorporating INH-ODN sequences, including IRS 661, IRS 869, and IRS 954, were prepared by rolling circle amplification and were subcutaneously injected into MRL/lpr mice. The TLR7 blocker of the IRS 661 nanoflower and the TLR9 antagonist of the IRS 869 nanoflower could decrease autoantibodies, reduce cytokine secretion, and alleviate lupus nephritis in mice. However, the IRS 954 nanoflower, the TLR7 and TLR9 dual antagonist, did not have additive or opposing effects on lupus nephritis but only showed a decrease in serum IFNα, suggesting that the TLR7 and TLR9 antagonist may have a competition mechanism or signal-dependent switching relationship. INH-ODN nanoflowers were proposed as a novel and potential therapeutic nucleic acids for SLE.

GBP5 Inhibition Ameliorates the Progression of Lupus Nephritis by Suppressing NLRP3 Inflammasome Activation

ABSTRACT Background The inflammatory response and NLRP3 inflammasome activation are typical characteristics of lupus nephritis (LN). Guanylate-binding protein 5 (GBP5) has effects on the release of proinflammatory cytokines and the activation of NLRP3 inflammasome. However, it is largely unknown whether and how GBP5 contributes to the progression of LN. Methods To detect the role of GBP5 in LN, MRL/lpr mice were administrated with the lentiviral vectors that knockdown GBP5 via tail vein. Proximal tubular epithelial HK-2 cells were treated with LPS and ATP to mimic the inflammatory response of LN in vitro. Results GBP5 expression was increased in the renal cortical tissues of LN mice. The in vivo results showed that GBP5 inhibition prevented the progression of LN, as evidenced by the decreased levels of 24-hour proteinuria, blood urea nitrogen and creatinine, accompanied by the ameliorated renal pathological damages. The increased mRNA and protein levels of proinflammatory factors (IL-6, TNF-α, iNOS and COX-2) in the renal cortex of LN mice were suppressed by GBP5 knockdown. In vitro, we demonstrated that the treatment of LPS combined with ATP induced an increase in GBP5 mRNA and protein expression in HK-2 cells. Mechanically, knockdown of GBP5 inhibited the activation of NLRP3 inflammasome and the secretion of IL-1β and IL-18 both in vivo and in vitro. Conclusion Our findings reveal that GBP5 inhibition prevents the progression of LN, most likely by suppressing NLRP3 inflammasome activation. It provides a novel insight into the therapeutic interventions for LN.

Saponins from Panax notoginseng ameliorate steroid resistance in lupus nephritis through regulating lymphocyte-derived exosomes in mice.

Lupus nephritis (LN) is the most common and severe type of organ damage and an important primary disease in end-stage renal failure in patients with systemic lupus erythematosus (SLE). Clinical guidelines recommend steroid treatment, but steroid resistance has become a major factor leading to treatment failure and affecting prognosis. Our previous study demonstrated that Saponins from Panax Notoginseng (Panax ginseng saponins, PNS) could reverse steroid resistance of lymphocytes by downregulating P-glycoprotein (P-gp) expression and provide renal protection in LN mice, but the mechanism by which lymphocytes transmit these related messages to renal lamina propria cells is not clear. Therefore, we further elucidated this mechanism through holistic experiments. In this study, low-dose methylprednisolone (0.8 mg/kg/day, MP) was used to induce a steroid-resistant lupus nephritis (SR-LN) mouse model in weeks one to four, and a therapeutic steroid dosage (MP 12 mg/kg/day) or a combined PNS (PNS 100 mg/kg/day) treatment was administered from week five to eight. Lymphocyte-derived exosomes (Lyme-Exos) were isolated from the spleens of mice and injected into untreated homozygous LN mice for 14 days via the tail vein. At the end of the experiment, the efficacy and mechanism of action of different groups of Lyme-Exos on LN mice were observed. The results revealed that exogenously injected Lyme-Exos were effectively taken up by the kidney and affected the progression of kidney disease. Steroid-resistant lymphocyte-derived exosomes intervented with PNS significantly downregulated the levels of silent information regulator-related enzyme 1 (Sirt1), multidrug resistance gene 1 (MDR1), and P-gp in the renal cortex and glomerular endothelial cells (GECs); reduced serum autoantibody [antinuclear antibody (ANA) and anti-double-stranded DNA (dsDNA)] levels and inflammatory markers (WBC, PCR, and PCT); improved renal function; and attenuated urinary microalbumin excretion. Additionally, renal histopathological damage (HE staining) and fibrosis (Masson staining) were improved, and immune complex (IgG) deposition and membrane attack complex (C5b-9) production were significantly reduced; the gene levels of inflammatory factors (INF-γ, MCP-1, IL-8, IL-17, vWF, VCAM-1, IL-1β, IL-6, PTX3) in the renal cortex were downregulated. Taken together, this study showed that PNS may alleviate steroid resistance in GEC by interfering with steroid-resistant Lyme-Exos to ameliorate LN progression, which will likely provide insights into developing a new LN treatment.

Multifunctional Polydopamine-Based Nanoparticles for Dual-Mode Imaging Guided Targeted Therapy of Lupus Nephritis.

Lupus nephritis (LN) is a common and refractory inflammation of the kidneys caused by systemic lupus erythematosus. Diagnosis and therapies at this stage are inefficient or have severe side effects. In recent years, nanomedicines show great potential for imaging diagnosis and controlled drug release. Herein, we developed a polydopamine (PDA)-based nanocarrier modified with Fe3O4 and Pt nanoparticles and loaded with necrostatin-1 (Nec-1) for the bimodal imaging and therapy of LN. Results demonstrate that Nec-1/PDA@Pt-Fe3O4 nanocarrier exhibits good biocompatibility. Nec-1, as an inhibitor of receptor-interacting protein 1 kinase, can be used to inhibit receptor-interacting protein 1 kinase activity and then reduces inflammation due to LN. Experiments in vitro and in the LN mouse model confirmed that the nanocarrier can reduce neutrophil extracellular traps (NETs) production by RIPK1 and alleviate the progression of inflammation. Previous studies proved that Pt nanoparticles can catalyze H2O2 to produce oxygen. A blood oxygen graph of mouse photoacoustic tomography confirmed that Nec-1/PDA@Pt-Fe3O4 can generate oxygen to fight against the hypoxic microenvironment of LN. PDA and Fe3O4 are used as photographic developers for photoacoustic or magnetic resonance imaging. The preliminary imaging results support Nec-1/PDA@Pt-Fe3O4 potential for photoacoustic/magnetic resonance dual-mode imaging, which can accurately and non-invasively monitor microscopic changes due to diseases. Nec-1/PDA@Pt-Fe3O4 combining these advantages exhibited outstanding performance in LN imaging and therapy. This work offers valuable insights into LN diagnosis and therapy.

Effects of Lactobacillus plantarum HFY15 on Lupus Nephritis in Mice by Regulation of the TGF-β1 Signaling Pathway.

ObjectiveIn this study, the Lactobacillus plantarum HFY15 (LP-HFY15) strain isolated from naturally fermented yak yogurt was investigated. An animal model of lupus nephritis was established by pristane to verify the interventional effect of LP-HFY15 on mouse lupus nephritis by regulating the transforming growth factor-β1 (TGF-β1) signaling pathway.Materials and MethodsIndexes in mouse serum and tissues were detected by kits, pathological changes in mouse kidney were observed by hematoxylin-eosin (H&E) staining, and quantitative polymerase chain reaction (qPCR) was used to detect TGF-β 1-related expression in mouse kidney tissue, which further elucidated the mechanism of LP-HFY15.ResultsLP-HFY15 decreased the elevation of urinary protein and the levels of interleukin-6 (IL-6), IL-12, tumor necrosis factor alpha (TNF-α), and interferon γ (IFN-γ) in serum and kidney tissue. LP-HFY15 also reduced serum creatinine (SCr), blood urea nitrogen (BUN), total cholesterol (TC), triglyceride (TG), and raised total protein (TP), and albumin (ALB) levels in mice with nephritis. In addition, LP-HFY15 inhibited the positive rate of double-stranded deoxyribonucleic acid (dsDNA) antibodies in mice with nephritis. The observation of H&E sections showed that LP-HFY15 alleviated the glomerulus morphological incompleteness and inflammatory infiltration caused by nephritis. Further results showed that LP-HFY15 downregulated the mRNA expression of TGF-β1, vascular endothelial growth factor (VEGF), and nuclear factor kappa-B (NF-κB) in the kidneys of lupus nephritis mice, and the expression of inhibitor of NF-κB (IκB-α), copper/zinc superoxide dismutase (Cu/Zn-SOD), and manganese superoxide dismutase (Mn-SOD) was also upregulated.ConclusionThese results indicated that LP-HFY15 plays a significant role in experimental intervention for lupus nephritis. The effect of LP-HFY15 was positively correlated with its concentration, and the effect was similar to that of prednisone at 109 CFU/kg.