Lupus nephritis: new progress in diagnosis and treatment

Value of SLE-DAS in assessing disease activity in patients with systemic lupus erythematosus: a single-centre retrospective study

OBJECTIVES

This study aimed to evaluate the clinical value of the Systemic Lupus Erythematosus Disease Activity Score (SLE-DAS) for assessing disease activity in patients with SLE.

METHODS

Clinical data were collected from patients with SLE who were admitted at the Second Affiliated Hospital of Soochow University from January 2009 to December 2022. The glucocorticoid dose grading was used as the gold standard for disease activity assessment in SLE. The SLE-DAS value was calculated, and the SLE disease activity status was graded based on the SLE-DAS value. Another scoring criterion, the SLE Disease Activity Index 2000 (SLEDAI 2000), served as a control. Spearman correlation analysis was used to calculate the correlation between the scoring criteria and other variables.

RESULTS

The analysis included 396 patients with SLE. A strong correlation was found between SLE-DAS and SLEDAI 2000 (ρ=0.709, 95% CI 0.648 to 0.766, p<0.001), with median SLE-DAS and SLEDAI 2000 scores of 15.32 (7.90 to 24.45) and 13 (8 to 19), respectively. Compared with the SLEDAI 2000 value, the SLE-DAS value correlated better with glucocorticoid dose grading (ρ=0.434 vs 0.518), gammaglobulin use (ρ=0.170 vs 0.318) and immunosuppressant use (ρ=0.122 vs 0.221). A moderate correlation based on disease activity grading was found between SLE-DAS and glucocorticoid dose grading (ρ=0.441), whereas a mild correlation was observed between SLEDAI 2000 and glucocorticoid dose grading (ρ=0.325). Additionally, SLE-DAS revealed a positive correlation with severe thrombocytopenia, cardiac involvement and pulmonary involvement but not SLEDAI 2000.

CONCLUSION

Compared with SLEDAI 2000, SLE-DAS may provide a more accurate disease activity assessment in patients with SLE, especially those with severe thrombocytopenia and cardiopulmonary involvement.

Protopanaxadiol improves lupus nephritis by regulating the PTX3/MAPK/ERK1/2 pathway

Lupus nephritis (LN) is a kidney disease that occurs after systemic lupus erythematosus (SLE) affects the kidneys. Pentraxin 3 (PTX3) is highly expressed in the serum of patients with LN. Renal PTX3 deposition is directly related to clinical symptoms such as proteinuria and inflammation. The excessive proliferation of mesangial cells (MCs) is one of the representative pathological changes in the progression of LN, which is closely related to its pathogenesis. Protopanaxadiol (PPD) is the main component of ginsenoside metabolism and has not been reported in LN. The aim of this study was to investigate the relationship between PTX3 and mesangial cell proliferation and to evaluate the potential role and mechanism of PPD in improving LN. PTX3 is highly expressed in the kidneys of LN patients and LN mice and is positively correlated with renal pathological indicators, including proteinuria and PCNA. The excessive expression of PTX3 facilitated the proliferation of MCs, facilitated the activation of the MAPK/ERK1/2 signaling pathway, and increased the expression of HIF-1α. Further studies showed that PPD can effectively inhibit the abnormal proliferation of MCs with high expression of PTX3 and significantly improve LN symptoms such as proteinuria in MRL/lpr mice. The mechanism may be related to the inhibition of the PTX3/MAPK/ERK1/2 pathway. In this study, both in vitro, in vivo, and clinical sample results show that PTX3 is involved in the regulation of MCs proliferation and the early occurrence of LN. Natural active compound PPD can improve LN by regulating the PTX3/MAPK/ERK1/2 pathway.

Rutin alleviates lupus nephritis by inhibiting T cell oxidative stress through PPARγ

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by complex clinical symptoms and multi-organ damage. One of the most prevalent complications of SLE is lupus nephritis (LN). Rutin, a natural flavonoid compound found in various plants used in traditional Chinese medicine, has shown promising anti-inflammatory, antioxidant, and renal protective effects. In our study, we treated MRL/lpr mice, a model known for spontaneously developing LN, with Rutin. Our findings reveal that Rutin markedly reduced serum cytokine and autoantibody levels and decreased inflammatory cell infiltration in renal tissues, thereby ameliorating kidney pathology. In vitro experiments indicated that Rutin's therapeutic effect on LN is linked to its significant reduction of oxidative stress in T cells. Further investigations suggest that Rutin enhances oxidative stress management through the modulation of Peroxisome proliferator-activated receptor gamma (PPARγ). We observed that Rutin modulates PPARγ activity, leading to reduced transcriptional activity of NF-κB and STAT3, which in turn inhibits the secretion of inflammatory cytokines such as IL-6, TNF-α, and IL-17. In summary, Rutin can exert an antioxidant effect by regulating PPARγ and shows therapeutic action against LN.

Artemisinin and its derivatives as promising therapies for autoimmune diseases

Artemisinin, a traditional Chinese medicine with remarkable antimalarial activity. In recent years, studies demonstrated that artemisinin and its derivatives (ARTs) showed anti-inflammatory and immunoregulatory effects. ARTs have been developed and gradually applied to treat autoimmune and inflammatory diseases. However, their role in the treament of patients with autoimmune and inflammatory diseases in particular is less well recognized. This review will briefly describe the history of ARTs use in patients with autoimmune and inflammatory diseases, the theorized mechanisms of action of the agents ARTs, their efficacy in patients with autoinmmune and inflammatory diseases. Overall, ARTs have numerous beneficial effects in patients with autoimmune and inflammatory diseases, and have a good safety profile.

Efficacy and safety of telitacicept in patients with lupus nephritis: a single-center, real-world retrospective study

BACKGROUND

Telitacicept, an innovative drug used for the treatment of systemic lupus erythematosus (SLE), can effectively control disease progression and achieve favorable outcomes. While case reports have mentioned the use of Telitacicept in lupus nephritis (LN) treatment, its safety and efficacy in treating patients with LN have not been explored. Therefore, in this study, we aimed to evaluate the safety and efficacy of Telitacicept in managing patients with LN.

METHODS

In a single-center, real-world retrospective study, 30 LN patients with poor response or adverse reactions to conventional glucocorticoids at our Hospital were enrolled to receive Telitacicept. Patients were administered 160 mg of Telitacicept subcutaneously once a week for at least 24 weeks in addition to standard treatment. We assessed the SLE responder index-4 (SRI-4) at the beginning and the end of the treatment period, measured laboratory test indicators at 3, 6, and 9 months, and observed the occurrence of adverse events in these patients.

RESULTS

The SRI-4 response rate was 86.67% (n = 26), with a significantly lower systemic lupus erythematosus disease activity index (SLEDAI) score compared to the baseline. Post Telitacicept treatment, glucocorticoid intake of patients with LN significantly reduced from 50 (IQR:40, 51.25) at baseline to 10 (IQR:5,10) at the endpoint (Z = - 6.547, p < 0.001). Patients with LN showed significantly improved urine occult blood levels after Telitacicept therapy. While the complement (C3 and C4) contents increased, immunoglobulins (IgG, IgA and IgM) reduced markedly (p < 0.001). The negative rate of dsDNA reached 26.67% and adverse events were alleviated post treatment. Only two cases of LN-related adverse reactions were reported, including herpes and infectious fever, respectively. Telitacicept primarily serves as an agent for the induction of remission therapy, with an attainment of complete remission rate standing at a commendable 73.3%.

CONCLUSIONS

Telitacicept treatment reduced disease severity in patients with LN. The initial clinical trial provided supportive evidence for the effectiveness and safety of Telitacicept as a viable treatment option for LN, allowing a reduction in the daily glucocorticoid intake while maintaining a good safety profile, and improving hypocomplementation in LN management.

Novel mitophagy inducer alleviates lupus nephritis by reducing myeloid cell activation and autoantigen presentation

Lupus nephritis (LN) is one of the most severe manifestations of systemic lupus erythematosus (SLE), but its mechanism of onset remains unclear. Since impaired mitophagy has been implicated in multiple organs in SLE, we hypothesized that mitophagy dysfunction is critical in the development of LN and that pharmacologically targeting mitophagy would ameliorate this disease. Therefore, lupus-prone MRL/MpJ-Faslpr (MRL/lpr) and NZBWF1/J mice were treated with a novel mitophagy inducer, UMI-77, during their onset of LN. This treatment effectively mitigated kidney inflammation and damage as assessed by histology and flow cytometry. Furthermore, dendritic cell (DC)-T-cell coculture assay indicated that UMI-77 treatment attenuated DC function that would drive T-cell proliferation but did not directly influence the potent T-cell proliferation in lupus mice. UMI-77 also restored mitochondrial function and attenuated proinflammatory phenotypes in lupus DCs. Adoptive transfer of DCs from MRL/lpr mice augmented serum anti-dsDNA IgG, urine protein and T-cell infiltration of the kidney in MRL/MpJ mice, which could be prevented by either treating lupus donors in vivo or lupus DCs directly with UMI-77. UMI-77 also restored mitochondrial function in myeloid cells from patients with LN in vitro as evidenced by increased ATP levels. Thus, enhancing mitophagy in SLE restrains autoimmunity and limits kidney inflammation for LN development. Hence, our findings suggest targeting mitophagy as a tangible pathway to treat LN.

The influence and therapeutic effect of microbiota in systemic lupus erythematosus

Systemic erythematosus lupus (SLE) is an autoimmune disease involving multiple organs that poses a serious risk to the health and life of patients. A growing number of studies have shown that commensals from different parts of the body and exogenous pathogens are involved in SLE progression, causing barrier disruption and immune dysregulation through multiple mechanisms. However, they sometimes alleviate the symptoms of SLE. Many factors, such as genetic susceptibility, metabolism, impaired barriers, food, and sex hormones, are involved in SLE, and the microbiota drives the development of SLE either by depending on or interacting with these factors. Among these, the crosstalk between genetic susceptibility, metabolism, and microbiota is a hot topic of research and is expected to lay the groundwork for the amelioration of the mechanism, diagnosis, and treatment of SLE. Furthermore, the microbiota has great potential for the treatment of SLE. Ideally, personalised therapeutic approaches should be developed in combination with more specific diagnostic methods. Herein, we provide a comprehensive overview of the role and mechanism of microbiota in lupus of the intestine, oral cavity, skin, and kidney, as well as the therapeutic potential of the microbiota.

Blockade of Notch1 Signaling Alleviated Podocyte Injury in Lupus Nephritis Via Inhibition of NLRP3 Inflammasome Activation

To explore the role of Notch1 pathway in the pathogenesis of podocyte injury, and to provide novel strategy for podocyte repair in lupus nephritis (LN). Bioinformatics analysis and immunofluorescence assay were applied to determine the expression and localization of Notch1 intracellular domain1 (NICD1) in kidneys of LN patients and MRL/lpr mice. The stable podocyte injury model in vitro was established by puromycin aminonucleoside (PAN) treatment. Expression of inflammasome activation related gene was detected by qPCR. The podocytes with PAN treatment were cultured with or without N-S-phenyl-glycine-t-butylester (DAPT), an inhibitor of Notch1 pathway. NICD1, Wilm'stumor1 (WT1), nucleotide-binding oligomerization domain-like receptors 3 (NLRP3), and absent in melanoma-like receptors 2 (AIM2) were detected by western blot. In vivo, MRL/lpr mice were administrated with DAPT or vehicle. The LN symptoms were assessed. The podocyte injury was evaluated, and the NLRP3 in podocytes of mice was detected. Notch1 pathway was overactivated in glomeruli of LN patients. NICD1 was colocalized with podocytes of LN patients and MRL/lpr mice. The inflammasome-related genes were significantly increased in podocytes with PAN treatment. NICD1 and NLRP3 were significantly decreased, while WT1 was significantly increased in injured podocytes treated with DAPT in vitro. In vivo, lupus-like symptoms were alleviated in DAPT treatment group. Notch1 pathway was inhibited in kidneys of mice treated with DAPT. The renal inflammation was reduced and the podocyte injury was mitigated in DAPT treatment group. The NLRP3 was decreased in podocytes of mice treated with DAPT. Notch1 pathway was overactivated in podocytes of LN patients and MRL/lpr mice. Blockade of Notch1 pathway reduced renal inflammation and alleviated podocyte injury via inhibition of NLRP3 inflammasome activation in LN.

Advances in the pharmacological management of systemic lupus erythematosus

INTRODUCTION

Despite setbacks in clinical trials for systemic lupus erythematosus (SLE), three drugs have been approved for SLE and lupus nephritis (LN) treatment in the past decade. Several ongoing clinical trials, some viewed optimistically by the scientific community, underscore the evolving landscape. Emerging clinical data have established specific therapeutic targets in routine clinical practice for treating SLE, aiming to improve long-term outcomes.

AREAS COVERED

Research related to treatment of SLE and LN is discussed, focusing on randomized clinical trials during the last 5 years and recommendations for the management of SLE published by the European Alliance of Associations for Rheumatology (EULAR), American College of Rheumatology (ACR), Asia Pacific League of Associations for Rheumatology (APLAR), and Pan-American League of Associations of Rheumatology (PANLAR).

EXPERT OPINION

The landscape of SLE and LN treatments is evolving, as new drugs and combination treatment approaches redefine the traditional concepts of induction and maintenance treatment phases. As the therapeutic armamentarium in SLE continues to expand, the research focus is shifting from the imperative for new therapies to advancing our understanding of optimal treatment selection for individual patients, steering toward precision medicine strategies.

Discovery of lupus nephritis targeted inhibitors based on De novo molecular design: comprehensive application of vinardo scoring, ADMET analysis, and molecular dynamics simulation

Lupus Nephritis (LN) is an autoimmune disease affecting the kidneys, and conventional drug studies have limitations due to its imprecise and complex pathogenesis. Therefore, the aim of this study was to design a novel Lupus Nephritis-targeted drug with good clinical due potential, high potency and selectivity by computer-assisted approach.NIK belongs to the serine/threonine protein kinase, which is gaining attention as a drug target for Lupus Nephritis. we used bioinformatics, homology modelling and sequence comparison analysis, small molecule ab initio design, ADMET analysis, molecular docking, molecular dynamics simulation, and MM/PBSA analysis to design and explore the selectivity and efficiency of a novel Lupus Nephritis-targeting drug, ClImYnib, and a classical NIK inhibitor, NIK SMI1. We used bioinformatics techniques to determine the correlation between lupus nephritis and the NF-κB signaling pathway. De novo drugs design was used to create a NIK-targeted inhibitor, ClImYnib, with lower toxicity, after which we used molecular dynamics to simulate NIK SMI1 against ClImYnib, and the simulation results showed that ClImYnib had better selectivity and efficiency. Our research delves into the molecular mechanism of protein ligands, and we have designed and validated an excellent NIK inhibitor using multiple computational simulation methods. More importantly, it provides an idea of target designing small molecules.Communicated by Ramaswamy H. Sarma.

Noninvasive biomarkers for lupus nephritis

Lupus nephritis (LN) is one of the most severe clinical manifestations of systemic lupus erythematosus (SLE). Notably, the clinical manifestations of LN are not always consistent with the histopathological findings. Therefore, the diagnosis and activity monitoring of this disease are challenging and largely depend on invasive renal biopsy. Renal biopsy has side effects and is associated with the risk of bleeding and infection. There is a growing interest in the development of novel noninvasive biomarkers for LN. In this review, we summarize most of the LN biomarkers discovered so far by correlating current knowledge with future perspectives. These biomarkers fundamentally reflect the biological processes of kidney damage and repair during disease. Furthermore, this review highlights the role of urinary cell phenotype detection in the diagnosis, monitoring, and treatment of LN and summarizes the limitations and countermeasures of this test.

LATS2 degradation promoted fibrosis damage and rescued by vitamin K3 in lupus nephritis

BACKGROUND

Lupus nephritis (LN) is the most common complication of systemic lupus erythematosus (SLE). The limited treatment options for LN increase the economic burdens on patients. Because fibrotic progression leads to irreversible renal damage in LN patients and further progresses to chronic kidney disease (CKD) and the end stage of renal disease (ESRD), developing new targets to prevent LN fibrotic progression could lead to a feasible treatment strategy for LN patients.

METHODS

In this study, we examined YAP activation and LATS2 downregulation in LN kidney biopsy samples (LN: n = 8, normal: n = 2) and lupus-prone MRL/lpr mice (n = 8 for each disease stage). The function of LATS2 was further investigated by in situ injection of Ad-LATS2 into mice with LN (n = 6 mice per group). We examined the role of SIAH2-LATS2 regulation by IP-MS and co-IP, and the protective effect of the SIAH2 inhibitor was investigated in mice with LN.

RESULTS

Restoring LATS2 by an adenovirus in vivo alleviated renal fibrotic damage in mice with LN. Moreover, we found that LATS2 was degraded by a K48 ubiquitination-proteasome pathway mediated by SIAH2 and promoted YAP activation to worsen fibrosis progression in LN. The H150 region of the substrate binding domain (SBD) is an important site for SIAH2-LATS2 binding. The SIAH2-specific inhibitor vitamin K3 protected against LN-associated fibrotic damage in vivo.

CONCLUSION

In summary, we identified the SIAH2-LATS2 axis as an attractive intervention target in LN to alter the resistance to fibrosis.

Comprehensive analysis of lactate-related gene profiles and immune characteristics in lupus nephritis

Objectives

The most frequent cause of kidney damage in systemic lupus erythematosus (SLE) is lupus nephritis (LN), which is also a significant risk factor for morbidity and mortality. Lactate metabolism and protein lactylation might be related to the development of LN. However, there is still a lack of relative research to prove the hypothesis. Hence, this study was conducted to screen the lactate-related biomarkers for LN and analyze the underlying mechanism.

Methods

To identify differentially expressed genes (DEGs) in the training set (GSE32591, GSE127797), we conducted a differential expression analysis (LN samples versus normal samples). Then, module genes were mined using WGCNA concerning LN. The overlapping of DEGs, critical module genes, and lactate-related genes (LRGs) was used to create the lactate-related differentially expressed genes (LR-DEGs). By using a machine-learning algorithm, ROC, and expression levels, biomarkers were discovered. We also carried out an immune infiltration study based on biomarkers and GSEA.

Results

A sum of 1259 DEGs was obtained between LN and normal groups. Then, 3800 module genes in reference to LN were procured. 19 LR-DEGs were screened out by the intersection of DEGs, key module genes, and LRGs. Moreover, 8 pivotal genes were acquired via two machine-learning algorithms. Subsequently, 3 biomarkers related to lactate metabolism were obtained, including COQ2, COQ4, and NDUFV1. And these three biomarkers were enriched in pathways 'antigen processing and presentation' and 'NOD-like receptor signaling pathway'. We found that Macrophages M0 and T cells regulatory (Tregs) were associated with these three biomarkers as well.

Conclusion

Overall, the results indicated that lactate-related biomarkers COQ2, COQ4, and NDUFV1 were associated with LN, which laid a theoretical foundation for the diagnosis and treatment of LN.

Ang-1, Ang-2, and Tie2 are diagnostic biomarkers for Henoch-Schönlein purpura and pediatric-onset systemic lupus erythematous

Henoch-Schönlein purpura (HSP) and pediatric-onset systemic lupus erythematosus (pSLE) are closely associated with vasculitis and vascular diseases. This study aimed to investigate the clinical diagnostic values of Ang-1, Ang-2, and Tie2 for HSP and pSLE. We surveyed 82 HSP patients, 34 pSLE patients, and 10 healthy children. The expression levels of Ang-1, Ang-2, and Tie2 in the serum and urine were assessed using enzyme-linked immunosorbent assay. The diagnostic values of Ang-1, Ang-2, and Tie2 for HSP and pSLE were evaluated using receiver operating characteristic curve analysis. The results revealed that the serum and urine expression levels of Ang-2 and Tie2 were significantly elevated in HSP and pSLE patients, whereas the Ang-1/Ang-2 values were reduced. Additionally, Ang-1 was highly expressed in the serum and urine of HSP patients and in the serum of pSLE patients. Ang-1, Ang-2, and Tie2 showed differential expression in various types of HSP and pSLE compared with their expression in healthy controls. In summary, Ang-1, Ang-2, and Tie2 can serve as biomarkers for HSP and pSLE. Moreover, Ang-1/Ang-2 values are reduced in HSP and pSLE patients. Ang-1, Ang-2, and Tie2 can be used as biomarkers for HSP and pSLE.

Research trends and frontiers in lupus nephritis: a bibliometric analysis from 2012 to 2022

OBJECTIVES

Lupus nephritis is a prevalent renal manifestation of systemic lupus erythematosus (SLE) and represents a significant cause of morbidity and mortality associated with the disease. This study endeavors to undertake a meticulous bibliometric analysis of LN publications to comprehend the research hotspots and future directions.

METHODS

The literature on LN was acquired from the Web of Science Core Collection (WoSCC). Co-occurrence and cooperative relationship analysis of authors, institutions, countries, journals, references and keywords in the publication was performed through CiteSpace, VOSviewer and a bibliometric online analysis platform. The knowledge graphs were created, and clustering and emergence analyses were performed.

RESULTS

According to the search strategy, a total of 2077 publications related to lupus nephritis (LN) have been identified, with China being the largest contributor globally. The Ohio State University emerged as the most prolific institution. Lupus is the most cited and published journal. Jan J Weening and Brad Rovin were the most prolific and cocited authors. The current research focus revolved around the "nirp3 inflammasome," "biomarker," and "voclosporin". "international society," "thrombotic microangiopathy (TMA)," and "pathway" were identified to be future research hotpots by keyword burst analysis.

CONCLUSIONS

This bibliometric analysis summarizes for the first time the progress of LN research (2012-2022), and qualitatively and quantitatively evaluates the bibliometric information of LN research. There has been a steady increase in the scientific literature on LN over the past 11 years, with an average growth rate of 7.27%. In this field, researchers are primarily based in China and the United States. The pathogenic mechanisms, management strategies and prognostic outcomes of LN are acknowledged as prospective research hotspots. Bibliometrically, the research status and trends of LN publications may greatly assist and be a significant reference for future research in the area.

Population-wide long-term study of incidence, renal failure, and mortality rates for lupus nephritis

OBJECTIVE

Given limited regional data, we investigate the state-wide epidemiology, renal and patient outcomes for lupus nephritis (LN) in Western Australia (WA).

METHODS

Patients hospitalized with incident SLE (≥2 diagnostic codes in the state-wide WA Health Hospital Morbidity Data Collection) in the period 1985-2015 were included (n = 1480). LN was defined by the presence of glomerulonephritis and/or raised serum creatinine. Trends over three study decades for annual incidence rate (AIR)/100.000 population, mortality (MR), and end-stage renal disease (ESRD) rates/100 person years were analyzed by least square regression and compared with a matched control group (n = 12 840).

RESULTS

Clinical evidence of LN developed in 366 SLE patients (25.9%) after a median disease duration of 10 months (IQR 0-101) with renal biopsy performed in 308 (84.2%). The AIR for LN (0.63/100.000) did not change significantly over time (R2  = .11, p = .85), while point prevalence reached 11.9/100.000 in 2015. ESRD developed in 14.1% (n = 54) of LN patients vs. 0.2% in non-LN SLE patients and 0.05% in controls (all p ≤ 0.01). ESRD rates increased over time in LN patients (0.4 to 0.7, R2 = .52, p = .26). The odds ratio for death was 8.81 (CI 3.78-22.9) for LN and 6.62 (CI 2.76-17.9) for non-LN SLE patients compared to controls and MR for LN patients increased over time (1.3 to 2.2, R2 = .84, p = .26).

CONCLUSIONS

The incidence rate of LN in WA remained unchanged over 30 years. A lack of improvement in renal failure and mortality rates illustrates the pressing need for better long-term treatment options and/or strategies in LN.

MicroRNA miR-181d-5p regulates the MAPK signaling pathway by targeting mitogen-activated protein kinase 8 (MAPK8) to improve lupus nephritis

BACKGROUND

Lupus nephritis (LN) is a common immune disease. The microRNA (miR)-181d-5p is a potential target for treating kidney injury. However, the therapeutic role of miR-181d-5p in LN has not been investigated. This study aimed to investigate the role of miR-181d-5p in targeting mitogen-activated protein kinase 8 (MAPK8) and stimulating the MAPK signaling pathway in LN.

METHODS

RT-qPCR was performed to identify the variations in miR-181d-5p expression in peripheral blood mononuclear cells (PBMCs) obtained from 42 LN patients, 30 healthy individuals, 6 MRL/lpr mice and 6 C57BL/6 mice. Western blot was used to detect the effect of miR-181d-5p on the MAPK signaling pathway in THP-1 cells and MRL/lpr mice. Enzyme-linked immunosorbent assay (ELISA) was utilized to detect the effect of miR-181d-5p on antinuclear antibodies and inflammatory factors. A dual-luciferase reporter assay was used to verify whether miR-181d-5p directly targets MAPK8. Flow cytometry was performed to evaluate apoptosis rates in transfected THP-1 cells.

RESULTS

miR-181d-5p expression was downregulated in PBMCs of LN patients (P < 0.01) and MRL/lpr mice (P < 0.05). A dual luciferase reporter assay demonstrated that miR-181d-5p inhibits MAPK8 (P < 0.01). Overexpression of miR-181d-5p inhibited the phosphorylation of p38 (P < 0.001) and p44/42 (P < 0.01). Moreover, miR-181d-5p decreased the apoptosis rate of THP-1 cells (P < 0.001), and reduced the secretion of IL-6 (P < 0.01) and TNF-α (P < 0.01). Furthermore, overexpression of miR-181d-5p decreased anti-dsDNA antibody (P < 0.05), anti-Sm antibody (P < 0.01), and fibrosis levels in MRL/lpr mice.

CONCLUSION

Upregulation of miR-181d-5p showed anti-inflammatory and anti-apoptotic effects on THP-1 cells in vitro and kidney injury in vivo. These effects were achieved by miR-181d-5p targeting MAPK8 to inhibit phosphorylation of p38 and p44/42. These results may offer new insights for improving therapeutic strategies against lupus nephritis.

Inhibition of STAT3 alleviates LPS-induced apoptosis and inflammation in renal tubular epithelial cells by transcriptionally down-regulating TASL

BACKGROUND

Systemic lupus erythematosus (SLE) is a common autoimmune disease that impacts various organs. Lupus nephritis (LN) significantly contributes to death in children with SLE. Toll-like receptor (TLR) adaptor interacting with SLC15A4 on the lysosome (TASL) acts as an innate immune adaptor for TLR and is implicated in the pathogenesis of SLE. A transcription factor known as signal transducer and activator of transcription 3 (STAT3), which is known to be linked to autoimmune diseases, is also involved in the development of SLE.

METHODS

Bioinformatics and real-time quantitative PCR (qRT-PCR) was used to detect the expression of STAT3 and TASL in peripheral blood of SLE patients and their correlation. Bioinformatics analysis, qRT-PCR, luciferase assay and chromatin immunoprecipitation (ChIP) were used to verify the regulation of transcription factor STAT3 on TASL. The expression levels of STAT3, TASL and apoptosis-related genes in LPS-induced HK2 cells were detected by qRT-PCR and Western blot. TUNEL staining were used to detect the apoptosis of HK2 cells after LPS stimulation. ELISA and qRT-PCR were used to detect the levels of inflammatory cytokines in the cell culture supernatant. TASL knockdown in HK2 cells was used to detect the changes in apoptosis-related genes and inflammatory factors. The expression level of TASL in LPS-stimulated HK2 cells and its effect on cell apoptosis and inflammatory factors were observed by knocking down and overexpressing STAT3, respectively. It was also verified in a rescue experiment.

RESULTS

The expressions of STAT3 and TASL were higher in SLE than in healthy children, and the expression of STAT3 was positively correlated with TASL. Transcription factor STAT3 can directly and positively regulate the expression of TASL through the promoter region binding site. The expression of STAT3, TASL and inflammatory cytokines was elevated, and the change of apoptosis was up-regulated in LPS-stimulated HK2 cells. Inhibition of STAT3 alleviates LPS-stimulated apoptosis and inflammatory response in HK2 cells through transcriptional regulation of TASL.

CONCLUSIONS

These findings provide new insights into the transcriptional regulation of TASL and provide new evidence of a direct regulatory relationship between signaling nodes in the lupus signaling network.

Changes in macrophage infiltration and podocyte injury in lupus nephritis patients with repeated renal biopsy: Report of three cases

BACKGROUND

In this study, we retrospectively analysed macrophage infiltration and podocyte injury in three patients with diffuse proliferative lupus nephritis (LN) who underwent repeated renal biopsy.

CASE SUMMARY

Clinical data of three diffuse proliferative LN patients with different pathological characteristics (case 1 was LN IV-G (A), case 2 was LN IV-G (A) + V, and case 3 was LN IV-G (A) + thrombotic microangiopathy) were reviewed. All patients underwent repeated renal biopsies 6 mo later, and renal biopsy specimens were studied. Macrophage infiltration was assessed by CD68 expression detected by immunohistochemical staining, and an immunofluorescence assay was used to detect podocin expression to assess podocyte damage. After treatment, Case 1 changed to LN III-(A), Case 2 remained as type V LN lesions, and Case 3, which changed to LN IV-S (A), had the worst prognosis. We observed reduced macrophage infiltration after therapy. However, two of the patients with active lesions after treatment still showed macrophage infiltration in the renal interstitium. Before treatment, the three patients showed discontinuous expression of podocin. Notably, the integrity of podocin was restored after treatment in Case 1.

CONCLUSION

It may be possible to reverse podocyte damage and decrease the infiltrating macrophages in LN patients through effective treatment.

Cytoskeleton Rearrangement in Podocytopathies: An Update

Podocyte injury can disrupt the glomerular filtration barrier (GFB), leading to podocytopathies that emphasize podocytes as the glomerulus's key organizer. The coordinated cytoskeleton is essential for supporting the elegant structure and complete functions of podocytes. Therefore, cytoskeleton rearrangement is closely related to the pathogenesis of podocytopathies. In podocytopathies, the rearrangement of the cytoskeleton refers to significant alterations in a string of slit diaphragm (SD) and focal adhesion proteins such as the signaling node nephrin, calcium influx via transient receptor potential channel 6 (TRPC6), and regulation of the Rho family, eventually leading to the disorganization of the original cytoskeletal architecture. Thus, it is imperative to focus on these proteins and signaling pathways to probe the cytoskeleton rearrangement in podocytopathies. In this review, we describe podocytopathies and the podocyte cytoskeleton, then discuss the molecular mechanisms involved in cytoskeleton rearrangement in podocytopathies and summarize the effects of currently existing drugs on regulating the podocyte cytoskeleton.

Traditional Chinese medicine for the treatment of immune-related nephropathy: A review

Immune-related nephropathy (IRN) refers to immune-response-mediated glomerulonephritis and is the main cause of end-stage renal failure. The pathogenesis of IRN is not fully understood; therefore, treatment is challenging. Traditional Chinese medicines (TCMs) have potent clinical effects in the treatment of the IRN conditions immunoglobulin A nephropathy, lupus nephropathy, and diabetic nephropathy. The underlying mechanisms mainly include its inhibition of inflammation; improvements to renal interstitial fibrosis, oxidative stress, autophagy, apoptosis; and regulation of immunity. In this review, we summarize the clinical symptoms of the three IRN subtypes and the use of TCM prescriptions, herbs, and bioactive compounds in treating IRN, as well as the potential mechanisms, intending to provide a reference for the future study of TCM as IRN treatments.

Circulating exosomal microRNAs as biomarkers of lupus nephritis

Objective

Disruption in the delicate symphony of genes, microRNA (miRNA), or protein expression can result in the dysregulation of the immune system, leading to the devastating consequences such as lupus nephritis (LN). The capacity of exosomes to transport miRNAs between cells and modify the phenotype of recipient cells implies their involvement in persistent kidney inflammation. This study unveils identifying two previously undiscovered exosomal miRNAs in the serum of LN patients, offering potential solutions to the current challenges in LN diagnosis and management.

Methods

Initially, we used a reagent-based kit to isolate serum exosomes from patients with Systemic lupus erythematosus (SLE) and used Trizol method for total RNA extraction. Subsequently, we employed small RNA sequencing to screen for differential expression profiles of exosomal small RNAs. The RT-qPCR method was used to individually validate samples in both the screening and validation cohorts, enabling the identification of candidate small RNAs; specific to LN. We assessed the diagnostic potency using receiver operating characteristic (ROC) curve, and explored the biological roles of miRNAs using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses.

Results

Compared to SLE patients without LN, SLE patients accompanied by LN exhibited significantly spiked levels of exosomal hsa-miR-4796-5p and hsa-miR-7974. The duo of miRNAs, hsa-miR-4796-5p and hsa-miR-7974, exhibited promising potential as biomarkers for diagnosing LN, with an AUC exceeding 0.8. Correlation analysis revealed a strong positive association between these miRNAs and proteinuria, as well as the SLE Disease Activity Index (SLEDAI) score. Moreover, the levels of two miRNAs in LN patients were significantly elevated in comparison to other autoimmune nephritis conditions, such as immunoglobulin A nephropathy (IgAN) and diabetic nephropathy (DN). Furthermore, the bioinformatics analysis indicated that this miRNAs duo can play a pivotal role in the regulation of immune processes by modulating signal pathways, such as the mTOR and PI3K-Akt signaling pathway.

Conclusion

This study provides a new ground that serum exosomal miRNAs can effectively identify and predict LN in SLE patients.

Efficacy and safety of belimumab in patients with lupus nephritis: a real-world retrospective observational study

OBJECTIVES

To evaluate the differences in efficacy and safety between Lupus Nephritis (LN) patients who received belimumab plus standard therapy and those who received only standard therapy in real world practice.

METHODS

Patients diagnosed with LN at the First Affiliated Hospital of Wenzhou Medical University from November 2012 to July 2023 were identified, and eligible cases were divided into two groups according to whether they received additional treatment with belimumab during the course of the disease.

RESULTS

A total of 1,169 LN patients were identified from our follow-up database. 112 patients receiving add-on treatment with belimumab (BLM group) and 112 control patients matched for relevant baseline characteristics were enrolled in this study. The median duration of treatment with belimumab was 13.82 [7.24, 20.29] months. Compared with the control group, the BLM group had more significant improvement in disease activity indicators such as serum albumin and complement levels, significantly lower B cell count, immunoglobulin, and earlier first attainment of renal remission, but there was no significant improvement in renal function and kidney-related events or death during the 2-year follow-up period. In the BLM group, the treatment effect of belimumab was more prominent in patients with lower levels of proteinuria. The safety profile of belimumab treatment was favorable, with a lower incidence of respiratory tract infection in the BLM group than in the control group during the follow-up period (p= 0.015).

CONCLUSIONS

This real-world study revealed that add-on treatment with belimumab provided better disease remission, and the therapeutic effect was more significant in patients with lower proteinuria levels. In addition, it had a favorable safety profile and reduced the risk of respiratory tract infection.

Correlations of baseline neutrophil-lymphocyte ratio with prognosis of patients with lupus nephritis: A single-center experience

Objective

We aimed to evaluate the correlations among the neutrophil-to-lymphocyte ratio (NLR), lupus nephritis (LN) clinical characteristics, and renal prognosis of patients with LN.

Methods

We enrolled 122 patients who were diagnosed with LN at the Rheumatology Department of the People's Hospital, Xinjiang Uygur Autonomous Region from January 2013 to April 2022. We determined the occurrence of renal adverse events in patients with LN by reviewing medical records and follow-up data. Correlations were analyzed using the Spearman test, and the quartile method was applied to classify all of the 122 patients who had completed follow-up into low, medium, and high NLR groups. The Kaplan-Meier survival curve was used to conduct survival analysis, and Cox regression analyses were used to explore possible potential risk factors.

Results

The baseline NLR of patients with LN was positively correlated with C-reactive protein (CRP), serum creatinine, blood urea nitrogen, and systemic lupus erythematosus disease activity index scores (P < 0.05) and negatively correlated with estimated glomerular filtration rate (eGFR) and serum albumin (P < 0.05). Patients who completed follow-up were divided into three NLR groups based on their NLR values: 30 in the low (NLR ≤ 2.21), 62 in the medium (NLR > 2.21 and NLR ≤ 6.17), and 30 in the high NLR group (NLR > 6.17). The patient survival time before developing poor renal prognosis was significantly different among the three groups (P < 0.05). High NLR (hazard ratio [HR] = 3.453, 95% confidence interval [CI]: 1.260-9.464), CRP (HR = 1.009, 95% CI: 1.002-1.017), eGFR (HR = 0.979, 95% CI: 0.963-0.995), and 24-h proteinuria values (HR = 1.237, 95% CI: 1.025-1.491) as well as anti-double stranded DNA antibody positivity (HR = 3.056, 95% CI:1.069-8.736) were independent risk factors associated with a poor renal prognosis for patients with LN.

Conclusion

The baseline NLR in peripheral blood can be used as a reference index for evaluating renal function and disease activity in patients with LN, and a high NLR has predictive value for the prognosis of patients with LN.

Imatinib and M351-0056 enhance the function of VISTA and ameliorate the development of SLE via IFN-I and noncanonical NF-κB pathway

V-domain immunoglobulin suppressor of T-cell activation (VISTA), an important negative checkpoint protein, participates in immunoregulation. Systemic lupus erythematosus (SLE) is an autoimmune disease in which patients exhibit high levels of autoantibodies and multi-organ tissue injury, primarily involving the kidney and skin. In wild-type (WT) mice and Vsir-/- mice with pristane-induced lupus-like disease, we found that VISTA deficiency exacerbated the lupus-like disease in mice, possibly through aberrant activation of type I interferon (IFN-I) signaling, CD4+ T cell, and noncanonical nuclear factor-κB (NF-κB) pathway. Surface plasmon resonance results showed that imatinib, an FDA-approved tyrosine kinase inhibitor, may have a high affinity for human VISTA-ECD with a KD value of 0.2009 μM. The biological activities of imatinib and VISTA agonist M351-0056 were studied in monocytes and T cells and in lupus-like disease murine model of chronic graft-versus-host disease (cGVHD) and lupus-prone MRL/lpr mice. VISTA small-molecule agonist reduced the cytokine production of peripheral blood mononuclear cells (PBMCs) and Jurkat cells and inhibited PBMCs proliferation. Moreover, they attenuated the levels of autoantibodies, renal injury, inflammatory cytokines, chemokines, and immune cell expansion in the cGVHD mouse model and MRL/lpr mice. Our findings also demonstrated that VISTA small-molecule agonist ameliorated the development of SLE through improving aberrantly activated IFN-I signaling and noncanonical NF-κB pathway. In conclusion, VISTA has a protective effect on the development and progression of SLE. VISTA agonist M351-0056 and imatinib have been firstly demonstrated to attenuate SLE, suggesting interventions to enhance VISTA function may be effective in treating SLE. VISTA deficiency exacerbates pristane-induced lupus-like disease in mice by promoting activation of the IFN-I and noncanonical NF-κB pathway. Imatinib was screened as a small-molecule VISTA agonist by molecular docking, SPR, and cellular level experiments. VISTA agonists (M351-0056 and imatinib) alleviated lupus-like disease progression in the cGVHD mouse model and MRL/lpr mice by inhibiting activation of IFN-I and noncanonical NF-κB pathway.

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

PURPOSE

Anti-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.

METHODS

Twenty-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.

RESULTS

Immunization 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.

CONCLUSION

Our 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.

Bilateral central serous retinal detachment in a patient with nephrotic syndrome: a case report

BACKGROUND

The aim of this report is to highlight the importance of considering nephrotic syndrome as a potential underlying cause of bilateral central serous retinal detachment in a patient with systemic lupus erythematosus and to underscore the significance of a comprehensive systemic workup in these patients.

CASE PRESENTATION

A 19-year-old Iranian female patient with history of systemic lupus erythematosus presented with progressive vision loss and bilateral macular elevation. Ophthalmic examination revealed periorbital edema, chemosis, and subretinal fluid at the macula of both eyes. Optical coherence tomography confirmed the existence of subretinal fluid and serous detachment located at the macula of both eyes. On fluorescein angiography, there were no signs of subretinal leakage such as smoke stack sign or expansile dot in late phases. Laboratory tests detected hypoalbuminemia and significant proteinuria, leading to the diagnosis of nephrotic syndrome. Treatment with prednisolone and albumin infusion resulted in improved visual acuity and resolution of subretinal fluid.

CONCLUSION

Nephrotic syndrome can be a rare underlying cause of bilateral central serous retinal detachment, and its association with systemic lupus erythematosus should be considered. Hypoalbuminemia in nephrotic syndrome alters fluid dynamics in the retina, contributing to bilateral central serous retinal detachment. Early recognition and management of nephrotic syndrome are essential for vision recovery and preventing long-term complications.

Biomarkers Associated with Drugs for the Treatment of Lupus Nephritis

The constant updating of lupus drug treatment guidelines has led to a question. How can the efficacy of treatment be more effectively monitored? Systemic lupus erythematosus (SLE) is a complex autoimmune disease that often presents clinically with multi-organ involvement, and approximately 30% of patients with SLE develop lupus nephritis (LN). Therefore, it is important to better track disease progression and drug efficacy. Now, kidney biopsy is still the gold standard for diagnosing and guiding the treatment of LN, but it is invasive and expensive. If simple, non-invasive and effective biomarkers can be found, drug intervention and prognosis can be better monitored and targeted. In this review, we focus on LN and explore biomarkers related to LN therapeutics, providing clinicians with more possibilities to track the therapeutic effect of drugs, improve treatment options and assess patient outcomes.

Novel insights into STAT3 in renal diseases

Signal transducer and activator of transcription 3 (STAT3) is a cell-signal transcription factor that has attracted considerable attention in recent years. The stimulation of cytokines and growth factors can result in the transcription of a wide range of genes that are crucial for several cellular biological processes involved in pro- and anti-inflammatory responses. STAT3 has attracted considerable interest as a result of a recent upsurge in study because of their role in directing the innate immune response and sustaining inflammatory pathways, which is a key feature in the pathogenesis of many diseases, including renal disorders. Several pathological conditions which may involve STAT3 include diabetic nephropathy, acute kidney injury, lupus nephritis, polycystic kidney disease, and renal cell carcinoma. STAT3 is expressed in various renal tissues under these pathological conditions. To better understand the role of STAT3 in the kidney and provide a theoretical foundation for STAT3-targeted therapy for renal disorders, this review covers the current work on the activities of STAT3 and its mechanisms in the pathophysiological processes of various types of renal diseases.

Research progress in functional magnetic resonance imaging assessment of lupus nephritis kidney injury

Lupus nephritis is one of the most common and severe complications of systemic lupus erythematosus and is also a major predictor of poor prognosis and mortality. Lupus nephritis has the characteristics of insidious onset, complex pathological types, rapid progression of organ damage, and easy recurrence. Currently, kidney damage in lupus nephritis is usually assessed based on urine analysis, renal biopsy, and glomerular filtration rates. However, they all have certain limitations, making it difficult to diagnose lupus nephritis early and assess its severity and progression. With the rapid development of functional magnetic resonance, multiple functional imaging techniques are expected to provide more useful information for the pathophysiological development, early diagnosis, progression, prognosis, and renal function evaluation of lupus nephritis. This article reviews the principle of multiple functional magnetic resonance imaging and the research status of evaluating renal function in lupus nephritis.

Decipher the Immunopathological Mechanisms and Set Up Potential Therapeutic Strategies for Patients with Lupus Nephritis

Lupus nephritis (LN) is one of the most severe complications in patients with systemic lupus erythematosus (SLE). Traditionally, LN is regarded as an immune complex (IC) deposition disease led by dsDNA-anti-dsDNA-complement interactions in the subendothelial and/or subepithelial basement membrane of glomeruli to cause inflammation. The activated complements in the IC act as chemoattractants to chemically attract both innate and adaptive immune cells to the kidney tissues, causing inflammatory reactions. However, recent investigations have unveiled that not only the infiltrating immune-related cells, but resident kidney cells, including glomerular mesangial cells, podocytes, macrophage-like cells, tubular epithelial cells and endothelial cells, may also actively participate in the inflammatory and immunological reactions in the kidney. Furthermore, the adaptive immune cells that are infiltrated are genetically restricted to autoimmune predilection. The autoantibodies commonly found in SLE, including anti-dsDNA, are cross-reacting with not only a broad spectrum of chromatin substances, but also extracellular matrix components, including α-actinin, annexin II, laminin, collagen III and IV, and heparan sulfate proteoglycan. Besides, the glycosylation on the Fab portion of IgG anti-dsDNA antibodies can also affect the pathogenic properties of the autoantibodies in that α-2,6-sialylation alleviates, whereas fucosylation aggravates their nephritogenic activity. Some of the coexisting autoantibodies, including anti-cardiolipin, anti-C1q, anti-ribosomal P autoantibodies, may also enhance the pathogenic role of anti-dsDNA antibodies. In clinical practice, the identification of useful biomarkers for diagnosing, monitoring, and following up on LN is quite important for its treatments. The development of a more specific therapeutic strategy to target the pathogenic factors of LN is also critical. We will discuss these issues in detail in the present article.

Disease modification achievement in patients with lupus nephritis in a real-life setting: mission impossible?

OBJECTIVE

A preliminary definition of disease modification (DM) in lupus nephritis (LN) was recently developed focusing on long-term remission and damage prevention, with minimal treatment-associated toxicity. We aimed to further specify aspects of DM criteria in LN, assess DM achievement in a real-world setting and examine potential DM predictors and long-term outcomes.

METHODS

We collected clinical/laboratory and histological inception cohort data from biopsy-proven LN patients (82% females) with ≥72 months follow-up at two joint academic centres. Specific criteria for 24-hour proteinuria, estimated glomerular filtration rate (eGFR), renal flares and glucocorticoids dose were set at three time frames (months 0-12, 13-60 and 72) to assess DM. In the first model, DM was achieved if patients fulfilled all four criteria at all three time frames (achievers). In the second model, the continued glucocorticoids reduction criterion was excluded. Logistic regression analyses were performed. Possible different trends in DM achievement between past and recent decades were also investigated.

RESULTS

DM was achieved by 60% of patients, increased to 70% when glucocorticoids excluded from DM criteria. 24-hour proteinuria at 9 months predicted DM achievement (OR 0.72, 95% CI 0.53 to 0.97, p=0.03), but none of baseline characteristics. Among patients with >72 month follow-up, non-achievers had worse renal outcomes (flares, >30% proteinuria increase, eGFR decline) than achievers at the end of follow-up (median 138 months). Patients diagnosed between 1992 and 2005 were found to have significantly lower percentages of DM achievement and met less often the glucocorticoids dose reduction criterion in all three time frames, compared with those diagnosed between 2006 and 2016 (p=0.006 and p<0.01, respectively).

CONCLUSIONS

DM was achieved by only 60% of LN patients in a real-life setting, partly due to lack of glucocorticoids dose target attainment, while DM failure was associated with worse long-term renal outcomes. This may imply limitations in the effectiveness or implementation of current LN treatments, supporting the need for novel therapeutic strategies.

Elevated serum levels of human epididymis protein 4 in adult patients with proliferative lupus nephritis

Background

This study aimed to access whether serum human epididymis protein 4 (HE4) level could identify lupus nephritis (LN) pathological classes in adults and children.

Methods

The serum HE4 levels of 190 healthy subjects and 182 patients with systemic lupus erythematosus (SLE) (61 adult-onset LN [aLN], 39 childhood-onset LN [cLN], and 82 SLE without LN) were determined using Architect HE4 kits and an Abbott ARCHITECT i2000SR Immunoassay Analyzer.

Results

Serum HE4 level was significantly higher in the aLN patients (median, 85.5 pmol/L) than in the patients with cLN (44 pmol/L, P < 0.001) or SLE without LN (37 pmol/L, P < 0.001), or the healthy controls (30 pmol/L, P < 0.001). Multivariate analysis showed that serum HE4 level was independently associated with aLN. Stratified by LN class, serum HE4 level was significantly higher in the patients with proliferative LN (PLN) than in those with non-PLN, and this difference was found only in aLN (median, 98.3 versus 49.3 pmol/L, P = 0.021) but not in cLN. Stratified by activity (A) and chronicity (C) indices, the aLN patients with class IV (A/C) possessed significantly higher serum HE4 levels than those with class IV (A) (median, 195.5 versus 60.8 pmol/L, P = 0.006), and this difference was not seen in the class III aLN or cLN patients.

Conclusion

Serum HE4 level is elevated in patients with class IV (A/C) aLN. The role of HE4 in the pathogenesis of chronic lesions of class IV aLN needs further investigation.

Reduced Renal CSE/CBS/H2S Contributes to the Progress of Lupus Nephritis

The molecular mechanisms underlying lupus nephritis (LN) pathogenesis are not fully understood. Hydrogen sulfide (H2S) is involved in many pathological and physiological processes. We sought to investigate the roles of H2S in LN pathogenesis. H2S synthase cystathionine-lyase (CSE) and cystathionine-synthetase (CBS) expression was downregulated in renal tissues of patients with LN and their levels were associated with LN's prognosis using the Nephroseq database. Reduced CSE and CBS protein expression in kidney tissues of LN patients and MRL/lpr mice were confirmed by immunohistochemistry. CSE and CBS mRNA levels were reduced in MRL/lpr and pristine- and R848-induced lupus mice. Given that H2S exerts an anti-inflammatory role partly via regulating inflammatory transcription factors (TFs), we analyzed hub TFs by using a bioinformatics approach. It showed that STAT1, RELA, and T-cell-related signaling pathways were enriched in LN. Increased STAT1 and RELA expression were confirmed in renal tissues of LN patients. Treatment of MRL/lpr and pristine mice with H2S donors alleviated systemic lupus erythematosus (SLE) phenotypes and renal injury. H2S donors inhibited RELA level and T-cell infiltration in the kidneys of MRL/lpr and pristine mice. Our data indicated that CSE/CBS/H2S contributes to LN pathogenesis. Supplementation of H2S would be a potential therapeutic strategy for LN.