Mesenchymal Stem Cells Control Complement C5 Activation by Factor H in Lupus Nephritis

Lupus mice derived mesenchymal stromal cells: Beneficial or detrimental on SLE disease outcome

BACKGROUND

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease characterized by the presence of autoantibodies against nuclear genes, deposition of immune complexes, and autoimmune T cells, through which, tissue damage would ultimately occur. Furthermore, loss of immune tolerance and imbalance of Th1/Th2 cells in addition to Th17/Treg are contributed to the pathogenesis of SLE. Mesenchymal stromal cells (MSCs) infusion is a potential therapy for SLE disease. Despite a majority of SLE patients achieving clinical remission after allogeneic MSC infusion from healthy individuals, SLE patients have less benefited from autologous MSC infusion, justifying the probable compromised function of SLE patients-derived MSCs. In this study, we aim to further investigate the potential immunoregulatory mechanisms in which mesenchymal stromal cells derived from pristane-induced lupus mice, following injection into healthy and lupus mice, exert their possible effects on the lupus process.

METHOD

40 female Balb/c mice aged 3 weeks were purchased and randomly divided into six groups. First, lupus disease was induced into the lupus groups by intraperitoneal injection of pristane and then the mice were surveyed for 6 months. The body weight, anti-dsDNA autoantibody levels, serum creatinine, and Blood Urea Nitrogen (BUN) levels were measured in two-month intervals. After 6 months, the group of lupus mice was sacrificed, and lupus MSCs were isolated. Two months later, cultured lupus MSCs were intravenously injected into two groups of healthy and lupus mice. After two months, the mice were euthanized and the kidneys of each group were examined histologically by hematoxylin & eosin (H&E) staining and the immunofluorescence method was also performed to evaluate IgG and C3 deposition. The frequency of splenic Th1, Th2, Th17, and Treg cells was measured by flow cytometry. Moreover, the cytokine levels of IFN-γ, IL-4, IL-17, and TGF-β in sera were measured by ELISA method.

RESULTS

Our results showed that the induction of lupus disease by pristane in Balb/c mice caused the formation of lipogranuloma, increased levels of anti-dsDNA autoantibodies, and impaired renal function in all pristane-induced lupus groups. In addition, the injection of lupus mesenchymal stromal cells (L-MSC) into healthy and lupus mice led to a further rise in anti-dsDNA serum levels, IgG and C3 deposition, and further dysfunction of mice renal tissue. Also, the flow cytometry results implicated that compared to the control groups, splenic Th1, Th2, and Th17 inflammatory cell subtypes and their secreted cytokines (IFN-γ, IL-4, and IL-17) in the sera of healthy and lupus mice were increased after the intake of L-MSC. Additionally, the splenic Treg cells were also significantly increased in the lupus mice receiving L-MSC. However, a decrease in serum levels of TGF-β cytokine was observed in healthy and lupus mice following L-MSC injection. In contrast, the lupus mice receiving healthy mesenchymal stem cells (H-MSC) manifested opposite results.

CONCLUSION

In a nutshell, our results suggest that although allogeneic MSCs are encouraging candidates for SLE treatment, syngeneic MSCs may not be eligible for treating SLE patients due to their defects in regulating the immune system in addition to their capability in promoting inflammation which would consequently worsen the SLE disease status.

Complement as a Biomarker for Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a disease of immune complex deposition; therefore, complement plays a vital role in the pathogenesis of SLE. In general, complement levels in blood and complement deposition in histological tests are used for the management of SLE. Thus, the evaluation of complement status can be useful in the diagnosis of SLE, assessment of disease activity, and prediction of treatment response and prognosis. In addition, novel complement biomarkers, such as split products and cell-bound complement activation products, are considered to be more sensitive than traditional complement markers, such as serum C3 and C4 levels and total complement activity (CH50), which become more widely used. In this review, we report the complement testing in the management of SLE over the last decade and summarize their utility.

Current Progress in Treating Systemic Lupus Erythematosus Using Exosomes/MicroRNAs

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease associated with impaired organ functions that can seriously affect the daily life of patients. Recent SLE therapies frequently elicit adverse reactions and side effects in patients, and clinical heterogeneity is considerable. Mesenchymal stromal cells (MSCs) have anti-inflammatory, tissue repair, and immunomodulatory properties. Their ability to treat autoimmune diseases largely depends on secreted extracellular vesicles, especially exosomes. The effects of exosomes and microRNAs (miRNAs) on SLE have recently attracted interest. This review summarizes the applications of MSCs derived from bone marrow, adipocyte tissue, umbilical cord, synovial membrane, and gingival tissue, as well as exosomes to treating SLE and the key roles of miRNAs. The efficacy of MSCs infusion in SLE patients with impaired autologous MSCs are reviewed, and the potential of exosomes and their contents as drug delivery vectors for treating SLE and other autoimmune diseases in the future are briefly described.

Mesenchymal stem cells and connective tissue diseases: From bench to bedside

The pathogenesis of connective tissue diseases (CTDs), represented by systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), primary Sjögren’s syndrome (pSS), and idiopathic inflammatory myopathies (IIM), includes various immune cells involved in both innate and adaptive immunity. The mesenchymal stem cells (MSCs) are unique due to their regulatory effect on immunity. This makes them a promising therapeutic approach for patients with immune-mediated disorders such as CTD. The safety and clinical efficacy of MSC treatment in CTD have been tested in a growing number of preclinical and clinical studies. Administration of MSCs has consistently shown benefits with both symptomatic and histologic improvement in CTD animal models. MSC therapies in severe and drug-resistant CTD patients have shown promise in a number of the pilot studies, cohort studies, and randomized controlled trials in SLE, RA, and SSc, but some problems still need to be resolved in the transition from the bench to the bedside. The relevant studies in pSS and IIM are still in their infancy, but have displayed encouraging outcomes. Considerable efficacy variations have been observed in terms of the route of delivery, time of MSC injection, origin of the MSCs and dosage. Furthermore, the optimization of conventional drugs combined with MSC therapies and the applications of novel cell engineering approaches requires additional research. In this review, we summarize the current evidence about the immunoregulatory mechanism of MSCs, as well as the preclinical and clinical studies of MSC-based therapy for the treatment of CTDs.

Extracellular Vesicles Released from Stem Cells as a New Therapeutic Strategy for Primary and Secondary Glomerulonephritis

Current treatment of primary and secondary glomerulopathies is hampered by many limits and a significant proportion of these disorders still evolves towards end-stage renal disease. A possible answer to this unmet challenge could be represented by therapies with stem cells, which include a variety of progenitor cell types derived from embryonic or adult tissues. Stem cell self-renewal and multi-lineage differentiation ability explain their potential to protect and regenerate injured cells, including kidney tubular cells, podocytes and endothelial cells. In addition, a broad spectrum of anti-inflammatory and immunomodulatory actions appears to interfere with the pathogenic mechanisms of glomerulonephritis. Of note, mesenchymal stromal cells have been particularly investigated as therapy for Lupus Nephritis and Diabetic Nephropathy, whereas initial evidence suggest their beneficial effects in primary glomerulopathies such as IgA nephritis. Extracellular vesicles mediate a complex intercellular communication network, shuttling proteins, nucleic acids and other bioactive molecules from origin to target cells to modulate their functions. Stem cell-derived extracellular vesicles recapitulate beneficial cytoprotective, reparative and immunomodulatory properties of parental cells and are increasingly recognized as a cell-free alternative to stem cell-based therapies for different diseases including glomerulonephritis, also considering the low risk for potential adverse effects such as maldifferentiation and tumorigenesis. We herein summarize the renoprotective potential of therapies with stem cells and extracellular vesicles derived from progenitor cells in glomerulonephritis, with a focus on their different mechanisms of actions. Technological progress and growing knowledge are paving the way for wider clinical application of regenerative medicine to primary and secondary glomerulonephritis: this multi-level, pleiotropic therapy may open new scenarios overcoming the limits and side effects of traditional treatments, although the promising results of experimental models need to be confirmed in the clinical setting.

Umbilical Cord Mesenchymal Stem Cells Ameliorate Kidney Injury in MRL/Ipr Mice Through the TGF-β1 Pathway

The therapeutic effects and mechanism of umbilical cord mesenchymal stem cells (UC-MSC) on kidney injury in MRL/Ipr mice were studied. UC-MSC, methylprednisolone (MP), and their combination were used to treat MRL/Ipr mice. The therapeutic effects were evaluated by renal function assessment, and HE, PAS, and Masson staining were carried out on renal tissues and visualized by electron microscopy. Subsequently, podocyte injury was detected by the presence of podocin in renal tissues by immunofluorescence. To further explore the mechanism, serum TGF-β1 was measured, and TGF-β1, p-Smad3, and TRAF6 in the renal tissue were detected by Western blotting. In vitro, TGF-β1 was used to stimulate podocytes, and the podocyte activity and changes in synaptopodin were observed after UC-MSC treatment. Significant improvements in renal function and pathological injury were observed in the UC-MSC group compared to the lupus nephritis (LN) model group. UC-MSC and MP treatment improved podocyte injury in MRL/Ipr mice. Western blot examination showed a significant increase in TGF-β1, p-Smad3, and TRAF6 expression in renal tissues of the LN model group, while significant downregulation of those proteins was observed in the UC-MSC group. After TGF-β1 stimulation in vitro, podocyte activity decreased, and UC-MSC treatment improved podocyte activity and restored synaptopodin expression. UC-MSC therapy could improve the deterioration of renal function and the pathological changes of the renal tissues in MRL/Ipr mice. Our study suggested that UC-MSC may improve kidney injury and podocyte injury in LN mice by inhibiting the TGF-β1 pathway.

Activated neutrophils in the initiation and progression of COVID-19: hyperinflammation and immunothrombosis in COVID-19

Coronavirus disease 2019 (COVID-19) is a pandemic respiratory disease caused by a novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-COV-2). COVID-19 is typically associated with fever and influenza-like symptoms in its early stages. Severe cases progress to acute respiratory distress syndrome/acute lung injury (ARDS/ALI), multiple organ damage, and even death. Until now, there has been a lack of specific and definitive treatment for COVID-19, which further challenges the situation. Previous clinical and laboratory data showed that neutrophils were significantly decreased in patients who died from COVID-19 in the early stages of disease; when patients were admitted to the hospital the number of neutrophils increased dramatically from 7 to 14 days after admission, which is correlated to myocardial and liver injury, thromboembolic complications, and poor prognosis. Autopsy findings revealed abundant neutrophil infiltration in the pulmonary capillaries and exudation into the alveolar cavity. Therefore, we speculate that neutrophils may play an important role in the initiation and progression of COVID-19. In this review, the relationship among the dynamic changes in neutrophils, cytokine storms, and the release of neutrophil extracellular traps (NETs) with the progression of COVID-19 was elucidated in detail. With a better understanding of the pathogenic mechanisms this can lead to improved clinical applications which are identified and discussed in this review.

Deep Learning-Based Model Significantly Improves Diagnostic Performance for Assessing Renal Histopathology in Lupus Glomerulonephritis

<b><i>Background:</i></b> Assessment of glomerular lesions and structures plays an essential role in understanding the pathological diagnosis of glomerulonephritis and prognostic evaluation of many kidney diseases. Renal pathophysiological assessment requires novel high-throughput tools to conduct quantitative, unbiased, and reproducible analyses representing a central readout. Deep learning may be an effective tool for glomerulonephritis pathological analysis. <b><i>Methods:</i></b> We developed a murine renal pathological system (MRPS) model to objectify the pathological evaluation via the deep learning method on whole-slide image (WSI) segmentation and feature extraction. A convolutional neural network model was used for accurate segmentation of glomeruli and glomerular cells of periodic acid-Schiff-stained kidney tissue from healthy and lupus nephritis mice. To achieve a quantitative evaluation, we subsequently filtered five independent predictors as image biomarkers from all features and developed a formula for the scoring model. <b><i>Results:</i></b> Perimeter, shape factor, minimum internal diameter, minimum caliper diameter, and number of objects were identified as independent predictors and were included in the establishment of the MRPS. The MRPS showed a positive correlation with renal score (<i>r</i> = 0.480, <i>p</i> &#x3c; 0.001) and obtained great diagnostic performance in discriminating different score bands (Obuchowski index, 0.842 [95% confidence interval: 0.759, 0.925]), with an area under the curve of 0.78–0.98, sensitivity of 58–93%, specificity of 72–100%, and accuracy of 74–94%. <b><i>Conclusion:</i></b> Our MRPS for quantitative assessment of renal WSIs from MRL/lpr lupus nephritis mice enables accurate histopathological analyses with high reproducibility, which may serve as a useful tool for glomerulonephritis diagnosis and prognosis evaluation.

Mesenchymal stem cell therapy attenuates complement C3 deposition and improves the delicate equilibrium between angiogenic and anti-angiogenic factors in abortion-prone mice

Immunological disorders are one of the main causes of recurrent spontaneous abortions (RSA). A rapidly expanding body of evidence indicates that excessive activation of the complement system is critically involved in the development of miscarriages. In the CBA/J × DBA/2 murine model of recurrent miscarriage, exaggerated and unrestrained complement activation is reported to be the underlying cause of angiogenic factor imbalance and persistent inflammation. We have previously shown that mesenchymal stem cell (MSC) therapy can significantly reduce the abortion rate in abortion-prone mice through regulating the feto-maternal immune response. In the present study, we hypothesized that MSCs might improve the balance of angiogenic factors at the feto-maternal unit of CBA/J × DBA/2 mice by restraining complement activation and deposition. To explore this hypothesis, autologous adipose tissue-derived mesenchymal stem cells (AD-MSCs) were administered intra-peritoneally to abortion-prone mice on the 4.5th day of gestation. Control mice received PBS as vehicle. On day 13.5 of pregnancy, deposition of the complement component C3 and expression levels of Crry, CFD (adipsin), VEGF, PlGF and FLT-1 were measured at the feto-maternal interface by immunohistochemistry and real-time PCR, respectively. Decidual cells were also cultured in RPMI 1640 medium for 48 h and VEGF and sFLT-1 protein levels were quantified in supernatants using enzyme-linked immunosorbent assay (ELISA). Our results indicated that MSC therapy significantly reduced C3 deposition and adipsin transcription in the fetal-maternal interface of abortion-prone mice. Furthermore, administration of MSCs robustly upregulated the mRNA expression levels of Crry, VEGF, PlGF and FLT-1 in the placenta and decidua of CBA/J × DBA/2 mice. Consistently, the in vitro results demonstrated that decidual cells obtained from MSC-treated dams produced increased concentrations of VEGF in culture supernatants, with concomitant decreased levels of sFLT-1 protein. Here, we show for the first time that adoptive transfer of MSCs rectifies the disturbed balance of angiogenic factors observed at the feto-maternal unit of CBA/J × DBA/2 mice, in part at least, through inhibiting excessive complement activation and promoting the production of angiogenic factors. Collectively, these alterations seem to play a pivotal role in reducing the abortion rate and improving the intrauterine condition for the benefit of the fetus.

Advances in Drug Therapy for Systemic Lupus Erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by a local or systemic inflammatory response. At present, the increasing research results show that the pathogenesis of the disease is complex, and the methods of clinical treatment also show diversity. This review analyzes and summarizes the existing mechanism research and drug treatment methods in order to provide a reference value for further drug research and development.

METHOD

We carried out a thorough literature search using databases. According to the main purpose of the article, irrelevant articles were excluded after further examination and directly relevant articles were included. Finally, the information related to the article was summarized.

RESULT

In this article, seventy-four articles are included. According to related articles, there are mainly four kinds of drugs, namely antimalarial drugs, glucocorticoids, immunosuppressive agents and biological agents. About fifty-five articles summarized the drugs for the treatment of systemic lupus erythematosus. The rest of the articles were related to the research progress of the mechanism of systemic lupus erythematosus.

CONCLUSION

This article describes the pathogenesis of systemic lupus erythematosus, and summarizes the traditional and new therapeutic drugs, which is not only beneficial to the treatment of lupus erythematosus patients, but also plays a vital reference significance for the future development of new systemic lupus erythematosus drugs.

Deposition of the Membrane Attack Complex in Healthy and Diseased Human Kidneys

The membrane attack complex-also known as C5b-9-is the end-product of the classical, lectin, and alternative complement pathways. It is thought to play an important role in the pathogenesis of various kidney diseases by causing cellular injury and tissue inflammation, resulting in sclerosis and fibrosis. These deleterious effects are, consequently, targeted in the development of novel therapies that inhibit the formation of C5b-9, such as eculizumab. To clarify how C5b-9 contributes to kidney disease and to predict which patients benefit from such therapy, knowledge on deposition of C5b-9 in the kidney is essential. Because immunohistochemical staining of C5b-9 has not been routinely conducted and never been compared across studies, we provide a review of studies on deposition of C5b-9 in healthy and diseased human kidneys. We describe techniques to stain deposits and compare the occurrence of deposits in healthy kidneys and in a wide spectrum of kidney diseases, including hypertensive nephropathy, diabetic nephropathy, membranous nephropathy, IgA nephropathy, lupus nephritis, C3 glomerulopathy, and thrombotic microangiopathies such as the atypical hemolytic uremic syndrome, vasculitis, interstitial nephritis, acute tubular necrosis, kidney tumors, and rejection of kidney transplants. We summarize how these deposits are related with other histological lesions and clinical characteristics. We evaluate the prognostic relevance of these deposits in the light of possible treatment with complement inhibitors.

An Overview of the Safety, Efficiency, and Signal Pathways of Stem Cell Therapy for Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that affects multiple organs and tissues. Mesenchymal stem cells (MSCs) are considered a good source for autoimmune disease and hematological disease therapy. This review will summarize the efficacy, safety, and mechanisms of MSC therapy for SLE. MSC therapy can reduce anti-dsDNA, antinuclear antigen (ANA), proteinuria, and serum creatinine in SLE patients. In animal models of SLE, MSC therapy also indicates that it could reduce anti-dsDNA, ANA, proteinuria, and serum creatinine and ameliorate renal pathology. There are no serious adverse events, treatment-related mortality, or tumor-related events in SLE patients after stem cell treatment. MSCs can inhibit inflammatory factors, such as MCP-1 and HMGB-1, and inhibit inflammation-related signaling pathways, such as the NF-κB, JAK/STAT, and Akt/GSK3β signaling pathways, to alleviate the lesions in SLE.

The immunomodulatory effects of mesenchymal stromal cell-based therapy in human and animal models of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune inflammatory disease with no absolute cure. Although the exact etiopathogenesis of SLE is still enigmatic, it has been well demonstrated that a combination of genetic predisposition and environmental factors trigger a disturbance in immune responses and thereby participate in the development of this condition. Almost all available therapeutic strategies in SLE are primarily based on the administration of immunosuppressive drugs and are not curative. Mesenchymal stromal cells (MSCs) are a subset of non-hematopoietic adult stem cells that can be isolated from many adult tissues and are increasingly recognized as immune response modulating agents. MSC-mediated inhibition of immune responses is a complex mechanism that involves almost every aspect of the immune response. MSCs suppress the maturation of antigen-presenting cells (DC and MQ), proliferation of T cells (Th1, T17, and Th2), proliferation and immunoglobulin production of B cells, the cytotoxic activity of CTL and NK cells in addition to increasing regulatory cytokines (TGF-β and IL10), and decreasing inflammatory cytokines (IL17, INF-ϒ, TNF-α, and IL12) levels. MSCs have shown encouraging results in the treatment of several autoimmune diseases, in particular SLE. This report aims to review the beneficial and therapeutic properties of MSCs; it also focuses on the results of animal model studies, preclinical studies, and clinical trials of MSC therapy in SLE from the immunoregulatory aspect.

Potential of Extracellular Vesicle-Associated TSG-6 from Adipose Mesenchymal Stromal Cells in Traumatic Brain Injury

Multipotent mesenchymal stromal cells (MSC) represent a promising strategy for a variety of medical applications. Although only a limited number of MSC engraft and survive after in vivo cellular infusion, MSC have shown beneficial effects on immunomodulation and tissue repair. This indicates that the contribution of MSC exists in paracrine signaling, rather than a cell-contact effect of MSC. In this review, we focus on current knowledge about tumor necrosis factor (TNF)-stimulated gene-6 (TSG-6) and mechanisms based on extracellular vesicles (EV) that govern long-lasting immunosuppressive and regenerative activity of MSC. In this context, in particular, we discuss the very robust set of findings by Jha and colleagues, and the opportunity to potentially extend their research focus on EV isolated in concentrated conditioned media (CCM) from adipose tissue derived MSC (ASC). Particularly, the authors showed that ASC-CCM mitigated visual deficits after mild traumatic brain injury in mice. TSG-6 knockdown ASC were, then, used to generate TSG-6-depleted CCM that were not able to replicate the alleviation of abnormalities in injured animals. In light of the presented results, we envision that the infusion of much distilled ASC-CCM could enhance the alleviation of visual abnormalities. In terms of EV research, the advantages of using size-exclusion chromatography are also highlighted because of the enrichment of purer and well-defined EV preparations. Taken together, this could further delineate and boost the benefit of using MSC-based regenerative therapies in the context of forthcoming clinical research testing in diseases that disrupt immune system homeostasis.

Lipocalin-2 Exacerbates Lupus Nephritis by Promoting Th1 Cell Differentiation

BACKGROUND

Lipocalin-2 (LCN2) is an indicator of the severity of lupus nephritis (LN) and plays a pivotal role in immune responses, but it is not known if its effect on LN pathogenesis derives from regulating the immune imbalance of T lymphocyte subsets.

METHODS

The expression of LCN2 in T cells and kidneys was assessed in renal biopsies from patients with LN. We investigated the relationship between LCN2 levels and development of LN and systemic illness by injecting anti-LCN2 antibodies into MRL/lpr mice and analyzing pristane-treated LCN2 ^-/- mice.

RESULTS

LCN2 is highly expressed in CD4⁺ T cells and in renal tissues, and is associated with severe renal damage in patients with LN and in mice with experimental lupus. LCN2 promotes IFN-γ overexpression in CD4⁺ T cells through the IL-12/STAT4 pathway in an autocrine or paracrine manner. Both neutralization of LCN2 in MRL/lpr mice and genetic depletion of LCN2 in pristane-induced lupus mice greatly ameliorate nephritis. The frequency and number of splenic and renal Th1 cells decrease in proportion to LN disease activity. Conversely, administration of LCN2 exacerbates the disease with significantly higher renal activity scores and increased numbers of Th1 cells.

CONCLUSIONS

LCN2 plays a crucial role in Th1 cell differentiation, and may present a potential therapeutic target for LN.

Lupus nephritis: challenges and progress

PURPOSE OF REVIEW

The management of lupus nephritis remains unsatisfactory due to insufficiently effective treatment regimens and the dearth of reliable predictors of disease onset or progression to guide individualized therapeutic decisions. This review summarizes new findings related to lupus nephritis over the last 18 months and discusses clinical needs that should be considered to advance trials of mechanism-based therapeutic strategies.

RECENT FINDINGS

Collaborative teams are addressing how to improve disease definitions and are developing predictive models for disease onset, disease response and risk of flare in individual patients. More attention is being paid to clinical trial design. Advanced technologic approaches are allowing the analysis of small amounts of human tissue and urine in unprecedented detail so as to discover new pathogenic mechanisms and identify disease biomarkers. Novel therapies continue to be tested in disease models and include new strategies to protect renal tissue from cell damage and fibrosis.

SUMMARY

The collaborative efforts of patients, clinical and translational researchers, the pharmaceutical industry and funding sources are needed to advance therapies for lupus nephritis. Specialized clinical centers can then deliver optimal and more personalized patient care that will improve patient outcomes.

IgG4 Autoantibodies Attenuate Systemic Lupus Erythematosus Progression by Suppressing Complement Consumption and Inflammatory Cytokine Production

Pathogenic autoantibodies can cause inflammation and tissue injury in systemic lupus erythematosus (SLE). Although IgG4 is considered non-inflammatory owing to the unique structure of its hinge region, the role of IgG4 autoantibodies in SLE remains largely unknown. The titers of serum anti-nuclear-IgG antibodies (ANA-IgG) and anti-nuclear-IgG4 antibodies (ANA-IgG4) in newly diagnosed SLE patients were detected. The effects of IgG4 purified from SLE patients (SLE IgG4) and healthy controls on complement consumption and inflammatory cytokine production were evaluated in vitro. The therapeutic effects of mouse IgG1 (functionally resembles human IgG4) purified from lupus-prone MRL-lpr/lpr mice (lupus IgG1) and control mice on disease progression were examined in MRL-lpr/lpr mice. The results showed that SLE patients with equal titers of total serum ANA-IgG (1:3,200) were divided into group I with lower ANA-IgG4 titers (≤ 1:10) and group II with higher ANA-IgG4 titers (≥ 1:100), and disease activity, inflammatory cytokine production, complement consumption, and renal-function parameters in group I SLE patients were more severe than those in group II. Further, compared with control IgG4, SLE IgG4 inhibited complement consumption by autoantibody-autoantigen immune complexes, and also inhibited inflammatory cytokines production by SLE PBMCs in vitro. Moreover, compared with control IgG1, lupus IgG1 exhibited a therapeutic effect on lupus by attenuating disease progression in MRL-lpr/lpr mice. These findings, for the first time, suggest that IgG4 autoantibodies can attenuate SLE progression by suppressing complement consumption and inflammatory cytokine production. Hence, this study may provide novel therapeutic strategies against SLE and other autoimmune diseases.

Efficacy of mesenchymal stem cells in animal models of lupus nephritis: a meta-analysis

BACKGROUND

Lupus nephritis is usually manifested by proteinuria, active urinary sediment, hypertension, and renal failure and is a serious complication with more than 50% occurrence in systemic lupus erythematosus patients. Mesenchymal stem cells (MSC) present remarkable immunomodulatory ability, and these cells are potential therapeutic agents for autoimmune disorders. In clinical trials, the effectiveness of MSC in the treatment of lupus nephritis is still controversial. A meta-analysis was performed to assess whether MSC can achieve good efficacy in the treatment of lupus nephritis in mice.

METHODS

A comprehensive literature search was performed in Cochrane Library, ISI Web of Science, PubMed, and EMBASE from inception to Oct 1, 2019. Two authors independently extracted the data, which were pooled and calculated using RevMan 5.3.

RESULTS

A total of 28 studies met the inclusion criteria. MSC treatment resulted in lower levels of ds-DNA (OR = - 29.58, 95% CI - 29.58, - 17.99; P < 0.00001), ANA (OR = - 70.93, 95% CI - 104.55, - 37.32; P < 0.0001), Scr (OR = - 8.20, 95% CI - 12.71, - 3.69; P = 0.0004), BUN (OR = - 14.57, 95% CI - 20.50, - 8.64; P < 0.00001), proteinuria (OR = - 4.26, 95% CI - 5.15 to - 3.37; P < 0.00001), and renal sclerosis score (OR = - 1.92, 95% CI - 2.66 to - 1.18; P < 0.00001), and MSC treatment could get higher levels of albumin. To detect the potential, the cytokines were also assessed, and the MSC treatment group had lower levels of IL-2, IL-12, IL-17, and IFN-γ when compared with the control group. However, the difference was not notable for IL-4, IL-6, IL-10, TGF-β, MCP-1, TNF-α, Th1, Th17, Foxp3, or Tregs.

CONCLUSION

Our study confirmed that MSC treatment in an animal model for lupus nephritis in the studies included in the meta-analysis resulted in lower levels of ds-DNA, ANA, Scr, BUN, proteinuria, and renal sclerosis score, and MSC treatment could get higher levels of albumin.

Transplantation of dental tissue-derived mesenchymal stem cells ameliorates nephritis in lupus mice

Background

Recently, clinical studies have suggested that transplantation of umbilical cord mesenchymal stem cells (UC-MSCs) were able to alleviate clinical symptoms of refractory systemic lupus erythematosus (SLE). Although dental tissue derived MSCs, including dental pulp stem cells (DPSCs) and periodontal ligament stem cell (PDLSCs), have been reported to possess immunomodulatory functions, whether they can ameliorate SLE symptoms as UC-MSCs remains to be elucidated.

Methods

We assessed the abilities of DPSCs and PDLSCs to treat SLE, cells were transferred intravenously to 28-week old B6/lpr mice. Ten weeks later, mice were sacrificed. Serum anti-dsDNA antibodies and anti-nuclear antibodies (ANA) were measured by ELISA. Renal pathology was analyzed by H&E, PAS and MASSON staining. Aggregation of IgG and IgM in the glomerulus was examined by immunofluorescence. Frequencies of Th1, Th2, Treg, Th17, Tfh, and plasma cells were determined by surface and intracellular staining. Serum IL-6, IL-10, IL-17 and MCP-1 were measured by Milliplex^® MAP technology.

Results

Same as UC-MSCs, both DPSCs and PDLSCs could efficiently downregulate 24-h proteinuria, anti-dsDNA antibodies and glomerular IgG/IgM in B6/lpr mice. However, DPSCs but not PDLSCs could ameliorate the glomerular lesion in B6/lpr mice. Compared to the phosphate buffered saline (PBS) group, percentages of Th1 (CD4⁺IFNγ⁺) cells and plasma (B220^-CD138⁺) cells in the spleen were significantly decreased in DPSCs and PDLSCs groups. There was no significant difference in Th2 (CD4⁺IL4⁺), Th17 (CD4⁺IL17⁺), Tfh (CD4⁺PD-1⁺CXCR5⁺) and Treg (CD4⁺CD25⁺Foxp3⁺) cells. Serum IL-6, IL-10, IL-17 and MCP-1 levels didn't change after MSCs transplantation.

Conclusions

Our results show that both DPSCs and PDLSCs can alleviate the disease symptoms of lupus-prone B6/lpr mice. DPSCs are also effective in reducing kidney glomerular lesion and perivascular inflammation infiltration as well as UC-MSCs, suggesting that DPSCs might be another choice for SLE treatment.