Neutrophils, Dendritic Cells, Toll-Like Receptors, and Interferon-α in Lupus Nephritis. Semin Nephrol. 2015;35:410-426. [PMID: 26573544 DOI: 10.1016/j.semnephrol.2015.08.003]

Mechanism of tacrolimus in the treatment of lupus nephritis

Systemic lupus erythematosus (SLE) is a complex autoimmune disorder, with more than half of the patients developing lupus nephritis (LN), which significantly contributes to chronic kidney disease (CKD) and end-stage renal disease (ESRD). The treatment of lupus nephritis has always been challenging. Tacrolimus (TAC), an effective immunosuppressant, has been increasingly used in the treatment of LN in recent years. This review aims to explore the mechanisms of action of tacrolimus in treating LN. Firstly, we briefly introduce the pharmacological properties of tacrolimus, including its role as a calcineurin (CaN) inhibitor, exerting immunosuppressive effects by inhibiting T cell activation and cytokine production. Subsequently, we focus on various other immunomodulatory mechanisms of tacrolimus in LN therapy, including its effects on T cells, B cells, and immune cells in kidney. Particularly, we emphasize tacrolimus' regulatory effect on inflammatory mediators and its importance in modulating the Th1/Th2 and Th17/Treg balance. Additionally, we review its effects on actin cytoskeleton, angiotensin II (Ang II)-specific vascular contraction, and P-glycoprotein activity, summarizing its impacts on non-immune mechanisms. Finally, we summarize the efficacy and safety of tacrolimus in clinical studies and trials. Although some studies have shown significant efficacy of tacrolimus in treating LN, its safety remains a challenge. We outline the potential adverse reactions of long-term tacrolimus use and provide suggestions on effectively monitoring and managing these adverse reactions in clinical practice. In general, tacrolimus, as a novel immunosuppressant, holds promising prospects for treating LN. Of course, further research is needed to better understand its therapeutic mechanisms and ensure its safety and efficacy in clinical practice.

Ex Vivo-Generated Tolerogenic Dendritic Cells: Hope for a Definitive Therapy of Autoimmune Diseases

Current therapies for autoimmune diseases are immunosuppressant agents, which have many debilitating side effects. However, dendritic cells (DCs) can induce antigen-specific tolerance. Tolerance restoration mediated by ex vivo-generated DCs can be a therapeutic approach. Therefore, in this review, we summarize the conceptual framework for developing ex vivo-generated DC strategies for autoimmune diseases. First, we will discuss the role of DCs in developing immune tolerance as a foundation for developing dendritic cell-based immunotherapy for autoimmune diseases. Then, we also discuss relevant findings from pre-clinical and clinical studies of ex vivo-generated DCs for therapy of autoimmune diseases. Finally, we discuss problems and challenges in dendritic cell therapy in autoimmune diseases. Throughout the article, we discuss autoimmune diseases, emphasizing SLE.

Machine learning-based identification of novel hub genes associated with oxidative stress in lupus nephritis: implications for diagnosis and therapeutic targets

BACKGROUND

Lupus nephritis (LN) is a complication of SLE characterised by immune dysfunction and oxidative stress (OS). Limited options exist for LN. We aimed to identify LN-related OS, highlighting the need for non-invasive diagnostic and therapeutic approaches.

METHODS

LN-differentially expressed genes (DEGs) were extracted from Gene Expression Omnibus datasets (GSE32591, GSE112943 and GSE104948) and Molecular Signatures Database for OS-associated DEGs (OSEGs). Functional enrichment analysis was performed for OSEGs related to LN. Weighted gene co-expression network analysis identified hub genes related to OS-LN. These hub OSEGs were refined as biomarker candidates via least absolute shrinkage and selection operator. The predictive value was validated using receiver operating characteristic (ROC) curves and nomogram for LN prognosis. We evaluated LN immune cell infiltration using single-sample gene set enrichment analysis and CIBERSORT. Additionally, gene set enrichment analysis explored the functional enrichment of hub OSEGs in LN.

RESULTS

The study identified four hub genes, namely STAT1, PRODH, TXN2 and SETX, associated with OS related to LN. These genes were validated for their diagnostic potential, and their involvement in LN pathogenesis was elucidated through ROC and nomogram. Additionally, alterations in immune cell composition in LN correlated with hub OSEG expression were observed. Immunohistochemical analysis reveals that the hub gene is most correlated with activated B cells and CD8 T cells. Finally, we uncovered that the enriched pathways of OSEGs were mainly involved in the PI3K-Akt pathway and the Janus kinase-signal transducer and activator of transcription pathway.

CONCLUSION

These findings contribute to advancing our understanding of the complex interplay between OS, immune dysregulation and molecular pathways in LN, laying a foundation for the identification of potential diagnostic biomarkers and therapeutic targets.

Association of Anti-Ro/SSA and Anti-La/SSB Autoantibodies With Pregnancy Outcome in the General Population

Background

Autoimmune diseases encompass a diverse array of disorders that disturb the optimal functioning of the immune system, which is to eliminate the 'foreign or/and dangerous' to mistakenly target the body's own tissues.

Objective

The aim of this research is to evaluate the most effective approach to managing autoimmune diseases within the framework of pregnancy.

Methods

The exact causes and etiologies of these diseases are multifactorial and mostly still unclear. Ro/SSA autoantibodies and La/SSB, could be found in Sjögren's disease (SJ), systemic lupus (SLE) and other autoimmune disorders. Smoking, stress, UV exposure, vitamin D deficiency, and other genetic and environmental factors have been identified as risk factors for rheumatic diseases.

Results

Over the years, an ever-increasing incidence of these diseases has been observed in the general population, with the female sex being at increased risk for their occurrence. This fact raises the question of what should be the management of these pathological entities during pregnancy. Taking into account the very significant impact on the quality of paitients'daily life and the seemingly augmented prevalence of autoimmune diseases, as well as their preference in the female population, the reasonable question arises as to what should be the optimal management of these diseases in the context of pregnancy.

Conclusion

Given the limited data of the global medical community regarding the etiological factors and mechanisms that trigger the onset of rheumatic diseases, the management of pregnant women is a complex conundrum that health professionals are challenged to face and solve.

The Role of the Oxidative State and Innate Immunity Mediated by TLR7 and TLR9 in Lupus Nephritis

Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus (SLE) and is considered one of the leading causes of mortality. Multiple immunological pathways are involved in the pathogenesis of SLE, which makes it imperative to deepen our knowledge about this disease's immune-pathological complexity and explore new therapeutic targets. Since an altered redox state contributes to immune system dysregulation, this document briefly addresses the roles of oxidative stress (OS), oxidative DNA damage, antioxidant enzymes, mitochondrial function, and mitophagy in SLE and LN. Although adaptive immunity's participation in the development of autoimmunity is undeniable, increasing data emphasize the importance of innate immunity elements, particularly the Toll-like receptors (TLRs) that recognize nucleic acid ligands, in inflammatory and autoimmune diseases. Here, we discuss the intriguing roles of TLR7 and TLR9 in developing SLE and LN. Also included are the essential characteristics of conventional treatments and some other novel and little-explored alternatives that offer options to improve renal function in LN.

Impact of nonalcoholic fatty liver disease-related metabolic state on depression

Nonalcoholic fatty liver disease (NAFLD), also recently referred as metabolic (dysfunction)-associated fatty liver disease (MAFLD), is characterized by hepatocyte steatosis in the setting of metabolic risk conditions and in the absence of an underlying precursor, for instance alcohol consumption, hepatotropic viruses and hepatotoxic drugs. A possible association between NAFLD and depression has been proposed, owing to intersecting pathophysiological pathways. This narrative review aimed to summarize the current evidence that illustrate the potential pathophysiological and clinical linkage between NAFLD-related metabolic state and depression. Prefrontal cortex lesions are suggested to be a consequence of liver steatosis-associated systematic hyperinflammatory state, a phenomenon also occurring in depression. In addition, depressive symptoms are present in neurotransmitter imbalances. These abnormalities seem to be correlated with NAFLD/MAFLD, in terms of insulin resistance (IR), ammonia and gut dysbiosis' impact on serotonin, dopamine, noradrenaline levels and gamma aminobutyric acid receptors. Furthermore, reduced levels of nesfatin-1 and copine-6-associated BDNF (brain-derived neurotrophic factor) levels have been considered as a probable link between NAFLD and depression. Regarding NAFLD-related gut dysbiosis, it stimulates mediators including lipopolysaccharides, short-chain fatty acids and bile acids, which play significant role in depression. Finally, western diet and IR, which are mainstay components of NAFLD/MAFLD, are, also, substantiated to affect neurotransmitters in hippocampus and produce neurotoxic lipids that contribute to neurologic dysfunction, and thus trigger emotional disturbances, mainly depressive symptoms.

Predicting diagnostic gene expression profiles associated with immune infiltration in patients with lupus nephritis

Objective

To identify potential diagnostic markers of lupus nephritis (LN) based on bioinformatics and machine learning and to explore the significance of immune cell infiltration in this pathology.

Methods

Seven LN gene expression datasets were downloaded from the GEO database, and the larger sample size was used as the training group to obtain differential genes (DEGs) between LN and healthy controls, and to perform gene function, disease ontology (DO), and gene set enrichment analyses (GSEA). Two machine learning algorithms, least absolute shrinkage and selection operator (LASSO) and support vector machine-recursive feature elimination (SVM-RFE), were applied to identify candidate biomarkers. The diagnostic value of LN diagnostic gene biomarkers was further evaluated in the area under the ROC curve observed in the validation dataset. CIBERSORT was used to analyze 22 immune cell fractions from LN patients and to analyze their correlation with diagnostic markers.

Results

Thirty and twenty-one DEGs were screened in kidney tissue and peripheral blood, respectively. Both of which covered macrophages and interferons. The disease enrichment analysis of DEGs in kidney tissues showed that they were mainly involved in immune and renal diseases, and in peripheral blood it was mainly enriched in cardiovascular system, bone marrow, and oral cavity. The machine learning algorithm combined with external dataset validation revealed that C1QA(AUC = 0.741), C1QB(AUC = 0.758), MX1(AUC = 0.865), RORC(AUC = 0.911), CD177(AUC = 0.855), DEFA4(AUC= 0.843)and HERC5(AUC = 0.880) had high diagnostic value and could be used as diagnostic biomarkers of LN. Compared to controls, pathways such as cell adhesion molecule cam, and systemic lupus erythematosus were activated in kidney tissues; cell cycle, cytoplasmic DNA sensing pathways, NOD-like receptor signaling pathways, proteasome, and RIG-1-like receptors were activated in peripheral blood. Immune cell infiltration analysis showed that diagnostic markers in kidney tissue were associated with T cells CD8 and Dendritic cells resting, and in blood were associated with T cells CD4 memory resting, suggesting that CD4 T cells, CD8 T cells and dendritic cells are closely related to the development and progression of LN.

Conclusion

C1QA, C1QB, MX1, RORC, CD177, DEFA4 and HERC5 could be used as new candidate molecular markers for LN. It may provide new insights into the diagnosis and molecular treatment of LN in the future.

Crosstalk between TBK1/IKKε and the type I interferon pathway contributes to tubulointerstitial inflammation and kidney tubular injury

The type I interferon (TI-IFN) pathway regulates innate immunity, inflammation, and apoptosis during infection. However, the contribution of the TI-IFN pathway or upstream signaling pathways to tubular injury in kidney disease is poorly understood. Upon observing evidence of activation of upstream regulators of the TI-IFN pathway in a transcriptomics analysis of murine kidney tubulointerstitial injury, we have now addressed the impact of the TI-IFN and upstream signaling pathways on kidney tubulointerstitial injury. In cultured tubular cells and kidney tissue, IFNα/β binding to IFNAR activated the TI-IFN pathway and recruited antiviral interferon-stimulated genes (ISG) and NF-κB-associated proinflammatory responses. TWEAK and lipopolysaccharide (LPS) signaled through TBK1/IKKε and IRF3 to activate both ISGs and NF-κB. In addition, TWEAK recruited TLR4 to stimulate TBK1/IKKε-dependent ISG and inflammatory responses. Dual pharmacological inhibition of TBK1/IKKε with amlexanox decreased TWEAK- or LPS-induced ISG and cytokine responses, as well as cell death induced by a complex inflammatory milieu that included TWEAK. TBK1 or IRF3 siRNA prevented the TWEAK-induced ISG and inflammatory gene expression while IKKε siRNA did not. In vivo, kidney IFNAR and IFNβ were increased in murine LPS and folic acid nephrotoxicity while IFNAR was increased in human kidney biopsies with tubulointerstitial damage. Inhibition of TBK1/IKKε with amlexanox or IFNAR neutralization decreased TI-IFN pathway activation and protected from kidney injury induced by folic acid or LPS. In conclusion, TI-IFNs, TWEAK, and LPS engage interrelated proinflammatory and antiviral responses in tubular cells. Moreover, inhibition of TBK1/IKKε with amlexanox, and IFNAR targeting, may protect from tubulointerstitial kidney injury.

Neutrophil extracellular traps: New players in cancer research

NETs are chromatin-derived webs extruded from neutrophils as a result of either infection or sterile stimulation using chemicals, cytokines, or microbes. In addition to the classical role that NETs play in innate immunity against infection and injuries, NETs have been implicated extensively in cancer progression, metastatic dissemination, and therapy resistance. The purpose of this review is to describe recent investigations into NETs and the roles they play in tumor biology and to explore their potential as therapeutic targets in cancer treatment.

Targeting DAMPs with nucleic acid scavengers to treat lupus

Systemic lupus erythematosus (SLE) is a chronic and often progressive autoimmune disorder marked clinically by a variable constellation of symptoms including fatigue, rash, joint pains, and kidney damage. The lungs, heart, gastrointestinal system, and brain can also be impacted, and individuals with lupus are at higher risk for atherosclerosis, thrombosis, thyroid disease, and other disorders associated with chronic inflammation . Autoimmune diseases are marked by erroneous immune responses in which the target of the immune response is a "self"-antigen, or autoantigen, driven by the development of antigen-specific B or T cells that have overcome the normal systems of self-tolerance built into the development of B and T cells. SLE is specifically characterized by the production of autoantibodies against nucleic acids and their binding proteins, including anti-double stranded DNA, anti-Smith (an RNA binding protein), and many others . These antibodies bind their nuclear-derived antigens to form immune complexes that cause injury and scarring through direct deposition in tissues and activation of innate immune cells . In over 50% of SLE patients, immune complex aggregation in the kidneys drives intrarenal inflammation and injury and leads to lupus nephritis, a progressive destruction of the glomeruli that is one of the most common causes of lupus-related death . To counter this pathology increasing attention has turned to developing approaches to reduce the development and continued generation of such autoantibodies. In particular, the molecular and cellular events that lead to long term, continuous activation of such autoimmune responses have become the focus of new therapeutic strategies to limit renal and other pathologies in lupus patients. The focus of this review is to consider how the innate immune system is involved in the development and progression of lupus nephritis and how a novel approach to inhibit innate immune activation by neutralizing the activators of this response, called Damage Associated Molecular Patterns, may represent a promising approach to treat this and other autoimmune disorders.

Immunomodulatory Activity of Mesenchymal Stem Cells in Lupus Nephritis: Advances and Applications

Lupus nephritis (LN) is a significant cause of various acute and chronic renal diseases, which can eventually lead to end-stage renal disease. The pathogenic mechanisms of LN are characterized by abnormal activation of the immune responses, increased cytokine production, and dysregulation of inflammatory signaling pathways. LN treatment is an important issue in the prevention and treatment of systemic lupus erythematosus. Mesenchymal stem cells (MSCs) have the advantages of immunomodulation, anti-inflammation, and anti-proliferation. These unique properties make MSCs a strong candidate for cell therapy of autoimmune diseases. MSCs can suppress the proliferation of innate and adaptive immune cells, such as natural killer cells (NKs), dendritic cells (DCs), T cells, and B cells. Furthermore, MSCs suppress the functions of various immune cells, such as the cytotoxicity of T cells and NKs, maturation and antibody secretion of B cells, maturation and antigen presentation of DCs, and inhibition of cytokine secretion, such as interleukins (ILs), tumor necrosis factor (TNF), and interferons (IFNs) by a variety of immune cells. MSCs can exert immunomodulatory effects in LN through these immune functions to suppress autoimmunity, improve renal pathology, and restore kidney function in lupus mice and LN patients. Herein, we review the role of immune cells and cytokines in the pathogenesis of LN and the mechanisms involved, as well as the progress of research on the immunomodulatory role of MSCs in LN.

Conversion of the liver into a biofactory for DNaseI using adeno-associated virus vector gene transfer reduces neutrophil extracellular traps in a model of Systemic Lupus Erythematosus

Adeno-associated virus (AAV) vectors are proving to be clinically transformative tools in the treatment of monogenic genetic disease. Rapid ongoing development of this technology promises to not only increase the number of monogenic disorders amenable to this approach, but also to bring diseases with complex multigenic and non-genetic aetiologies within therapeutic reach. Here we explore the broader paradigm of converting the liver into a biofactory for systemic output of therapeutic molecules using AAV-mediated delivery of DNaseI as an exemplar. DNaseI can clear neutrophil extracellular traps (NETs), which are nuclear-protein structures possessing anti-microbial action that are also involved in the pathophysiology of clinically troubling immune-mediated diseases. However, a translational challenge is short half-life of the enzyme in vivo (<5 hours). The current study demonstrates that AAV-mediated liver-targeted gene transfer stably induces serum DNaseI activity to >190-fold above physiological levels. In lupus-prone mice (NZBWF1) activity was maintained for longer than 6 months, the latest time point tested, and resulted in a clear functional effect with reduced renal presence of neutrophils, NETs, IgG and complement C3. However, treatment in this complex disease model did not extend life-span, improve serological endpoints or preserve renal function indicating there are elements of pathophysiology not accessible to DNaseI in the NZBWF1 model. We conclude that a translational solution to the challenge of short half-life of DNaseI is AAV-mediated gene delivery and that this may be efficacious in treating disease where NETs are a dominant pathological mechanism.

New-Onset Systemic Lupus Erythematosus after mRNA SARS-CoV-2 Vaccination

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease resulting from the interaction of genetic and environmental factors. In addition, some antiviral vaccines have been associated with the onset of SLE. Few cases of SLE occurring after SARS-CoV-2 mRNA have been reported. Herein, we report the case of a 27-year-old woman with type I diabetes mellitus and family history of SLE who presented with symmetric inflammatory polyarthritis of the proximal interphalangeal joints, metacarpophalangeal joints, wrists, knees, and ankles two weeks after receiving the second dose of the SARS-CoV-2 mRNA-1273 vaccine. Laboratory results revealed positive antinuclear, anti-dsDNA, anti-Ro, and anti-La/SSB antibodies and low C4 levels. She was initially treated with low-dose prednisone and hydroxychloroquine. Hydroxychloroquine was discontinued after she developed an urticarial rash. Subsequently, mycophenolate mofetil was added after she developed proteinuria. This case highlights the importance of considering the diagnosis of SLE in patients who present with inflammatory polyarthritis after COVID-19 vaccination.

Adeno-Associated Virus Vector Gene Delivery Elevates Factor I Levels and Downregulates the Complement Alternative Pathway In Vivo

The complement system is a key component of innate immunity, but impaired regulation influences disease susceptibility, including age-related macular degeneration and some kidney diseases. While complete complement inhibition has been used successfully to treat acute kidney disease, key unresolved challenges include strategies to modulate rather than completely inhibit the system and to deliver therapy potentially over decades. Elevating concentrations of complement factor I (CFI) restricts complement activation in vitro and this approach was extended in the current study to modulate complement activation in vivo. Sustained increases in CFI levels were achieved using an adeno-associated virus (AAV) vector to target the liver, inducing a 4- to 5-fold increase in circulating CFI levels. This led to decreased activity of the alternative pathway as demonstrated by a reduction in the rate of inactive C3b (iC3b) deposition and more rapid formation of C3 degradation products. In addition, vector application in a mouse model of systemic lupus erythematosus (NZBWF1), where tissue injury is, in part, complement dependent, resulted in reduced complement C3 and IgG renal deposition. Collectively, these data demonstrate that sustained elevation of CFI reduces complement activation in vivo providing proof-of-principle support for the therapeutic application of AAV gene delivery to modulate complement activation.

Low-Vacuum Scanning Electron Microscopy to Assess Histopathological Resolution of Class V Lupus Nephritis: A Case Report

Lupus nephritis (LN) is most frequently associated with poor outcomes in patients with systemic lupus erythematosus (SLE). LN manifests as histopathological changes in the kidney caused by immune complex formation and deposition. In particular, immunoglobulin G (IgG) deposits are frequently observed by immunofluorescence staining, which helps to establish the diagnosis of LN. In this case report, we describe a 57-year-old woman with SLE who had been undergoing treatment on an outpatient basis for 11 years. Her first and second renal biopsies revealed class V LN with a coarsely granular pattern of IgG deposition in the peripheral capillary walls. However, her third renal biopsy showed no IgG deposition, which indicated histopathological resolution of her class V LN. We used low-vacuum scanning electron microscopy (LV-SEM) to examine the three-dimensional structural alterations in her glomerular basement membranes. In this report, we describe findings that indicated resorption of epithelial deposits, that is, resolution of LN. The results of repeated kidney biopsies confirmed by LV-SEM suggested the possibility of a state unrelated to LN.

Interaction Mechanisms Between Major Depressive Disorder and Non-alcoholic Fatty Liver Disease

Major depressive disorder (MDD), which is highly associated with non-alcoholic fatty liver disease (NAFLD), has complex pathogenic mechanisms. However, a limited number of studies have evaluated the mutual pathomechanisms involved in MDD and NAFLD development. Chronic stress-mediated elevations in glucocorticoid (GC) levels play an important role in the development of MDD-related NAFLD. Elevated GC levels can induce the release of inflammatory factors and changes in gut permeability. Elevated levels of inflammatory factors activate the hypothalamic-pituitary-adrenal (HPA) axis, which further increases the release of GC. At the same time, changes in gut permeability promote the release of inflammatory factors, which results in a vicious circle among the three, causing disease outbreaks. Even though the specific role of the thyroid hormone (TH) in this pathogenesis has not been fully established, it is highly correlated with MDD and NAFLD. Therefore, changing lifestyles and reducing psychological stress levels are necessary measures for preventing MDD-related NAFLD. Among them, GC inhibitors and receptor antagonists may be key in the alleviation of early and mid-term disease progression. However, combination medications may be important in late-stage diseases, but they are associated with various side effects. Traditional Chinese medicines have been shown to be potential therapeutic alternatives for such complex diseases.

IgG-aggregates rapidly upregulate FcgRI expression at the surface of human neutrophils in a FcgRII-dependent fashion: A crucial role for FcgRI in the generation of reactive oxygen species

Autoimmune complexes are an important feature of several autoimmune diseases such as lupus, as they contribute to tissue damage through the activation of immune cells. Neutrophils, key players in lupus, interact with immune complexes through Fc gamma receptors (FcgR). Incubation of neutrophils with aggregated-IgGs caused degranulation and increased the surface expression of FcgRI within minutes in a concentration-dependent fashion. After 30 minutes, IgG aggregates (1 mg/mL) upregulated FcgRI by 4.95 ± 0.45-fold. FcgRI-positive neutrophils reached 67.24% ± 6.88% on HA-IgGs stimulated neutrophils, from 3.12% ± 1.62% in non-stimulated cells, ranking IgG-aggregates among the most potent known agonists. FcgRIIa, and possibly FcgRIIIa, appeared to mediate this upregulation. Also, FcgRI-dependent signaling proved necessary for reactive oxygen species (ROS) production in response to IgG-aggregates. Finally, combinations of bacterial materials with aggregates dramatically boosted ROS production. This work suggests FcgRI as an essential component in the response of human neutrophils to immune complexes leading to the production of ROS, which may help explain how neutrophils contribute to tissue damage associated with immune complex-associated diseases, such as lupus.

Toll-Like Receptor as a Potential Biomarker in Renal Diseases

One of the major challenges faced by modern nephrology is the identification of biomarkers associated with histopathological patterns or defined pathogenic mechanisms that may assist in the non-invasive diagnosis of kidney disease, particularly glomerulopathy. The identification of such molecules may allow prognostic subgroups to be established based on the type of disease, thereby predicting response to treatment or disease relapse. Advances in understanding the pathogenesis of diseases, such as membranous nephropathy, minimal change disease, focal segmental glomerulosclerosis, IgA (immunoglobulin A) nephropathy, and diabetic nephropathy, along with the progressive development and standardization of plasma and urine proteomics techniques, have facilitated the identification of an increasing number of molecules that may be useful for these purposes. The growing number of studies on the role of TLR (toll-like receptor) receptors in the pathogenesis of kidney disease forces contemporary researchers to reflect on these molecules, which may soon join the group of renal biomarkers and become a helpful tool in the diagnosis of glomerulopathy. In this article, we conducted a thorough review of the literature on the role of TLRs in the pathogenesis of glomerulopathy. The role of TLR receptors as potential marker molecules for the development of neoplastic diseases is emphasized more and more often, as prognostic factors in diseases on several epidemiological backgrounds.

Utilization of Biomarkers in Lupus Nephritis

Lupus nephritis (LN) occurs in up to 60% of SLE patients, and is a leading cause of disability and death. Current treatment of LN consists of a combination of high dose corticosteroids that non-specifically decrease inflammation and cytotoxic medications that reduce auto-antibody production. That combination of therapy is associated with significant side effects while remission rates remain inadequate. Since the introduction of biologics into the pharmacological armamentarium, there has been hope for less toxic and more effective therapies for LN. Unfortunately, after multiple clinical trials, no biologic has improved efficacy over standard of care therapies for LN. This is likely, in part, due to disease heterogeneity. The utilization of biomarkers in LN may provide a way to stratify patients and guide therapeutic options. In this review, we summarize traditional and novel LN biomarkers and discuss how they may be used to diagnose, stratify, and guide therapy in patients with LN, bringing precision medicine to the forefront of LN therapy.

Transcriptomic and Epigenetic Alterations in Dendritic Cells Correspond With Chronic Kidney Disease in Lupus Nephritis

Systemic lupus erythematosus (SLE) is a serious autoimmune disease with variety of organ manifestations. The most dreadful one, affecting the majority of SLE patients, is kidney manifestation-lupus nephritis (LN). Dendritic cells (DC) are believed to be one of the culprits of immune dysregulation in LN. Flow cytometry analysis was applied to identify the frequency and activity of peripheral blood DCs subpopulations: myeloid and plasmacytoid, in LN patients. Magnetically isolated mDCs and pDCs were subjected to molecular analysis of genes expression, evaluation of global DNA methylation and histone H3 methylation. We observed distinctive features of DCs associated with the stages of nephritis in LN patients. Lower numbers of pDCs were observed in patients with severe LN, while increased co-stimulatory potential of mDCs was connected with the early, mild stage of this disease. IRF1 transcript upregulation was specific for mDCs from total LN patients, while exceptional amount of IRF1 mRNA was detected in mDCs from severe LN patients. DCs DNA hypermethylation seemed characteristic for severe LN, whereas a decrease in H3K4me3 and H3K27me3 marks was significant for the early stages of LN. These findings present dendritic cell alterations that may reflect renal involvement in SLE, laying foundations for new strategy of diagnosis and monitoring of LN patients, omitting invasive kidney biopsies.

Extracellular DNA traps in inflammation, injury and healing

Following strong activation signals, several types of immune cells reportedly release chromatin and granular proteins into the extracellular space, forming DNA traps. This process is especially prominent in neutrophils but also occurs in other innate immune cells such as macrophages, eosinophils, basophils and mast cells. Initial reports demonstrated that extracellular traps belong to the bactericidal and anti-fungal armamentarium of leukocytes, but subsequent studies also linked trap formation to a variety of human diseases. These pathological roles of extracellular DNA traps are now the focus of intensive biomedical research. The type of pathology associated with the release of extracellular DNA traps is mainly determined by the site of trap formation and the way in which these traps are further processed. Targeting the formation of aberrant extracellular DNA traps or promoting their efficient clearance are attractive goals for future therapeutic interventions, but the manifold actions of extracellular DNA traps complicate these approaches.

Toll-like receptors in lupus nephritis

The pathogenesis of systemic autoimmune diseases such as systemic lupus erythematosus (SLE) is based on the loss of self-tolerance against ubiquitous autoantigens involving all mechanisms of adaptive immunity. However, data accumulating over the last decade imply an important role also for numerous elements of innate immunity, namely the Toll-like receptors in the pathogenesis of SLE. Here we discuss their role in the most common organ complication of SLE, i.e. lupus nephritis. We summarize experimental and clinical data on the expression and functional contribution of the Toll-like receptors in immune complex glomerulonephritis, and intrarenal inflammation. Based on these discoveries Toll-like receptors are evolving as therapeutic targets for the treatment of SLE and lupus nephritis.

Cellular and Molecular Mechanisms of Autoimmunity and Lupus Nephritis

Autoimmunity involves immune responses directed against self, which are a result of defective self/foreign distinction of the immune system, leading to proliferation of self-reactive lymphocytes, and is characterized by systemic, as well as tissue-specific, inflammation. Numerous mechanisms operate to ensure the immune tolerance to self-antigens. However, monogenetic defects or genetic variants that weaken immune tolerance render susceptibility to the loss of immune tolerance, which is further triggered by environmental factors. In this review, we discuss the phenomenon of immune tolerance, genetic and environmental factors that influence the immune tolerance, factors that induce autoimmunity such as epigenetic and transcription factors, neutrophil extracellular trap formation, extracellular vesicles, ion channels, and lipid mediators, as well as costimulatory or coinhibitory molecules that contribute to an autoimmune response. Further, we discuss the cellular and molecular mechanisms of autoimmune tissue injury and inflammation during systemic lupus erythematosus and lupus nephritis.

Differential reactive oxygen species production of neutrophils and their oxidative damage in patients with active and inactive systemic lupus erythematosus

OBJECTIVE

Increasing interest is given to the involvement of the innate immunity and especially Polymorphonuclear neutrophils (PMN) in the physiopathological process of inflammatory diseases such as systemic lupus erythematosus (SLE). Here, we investigated the oxidative burst and damages in SLE patients neutrophils, considering the two phases of the disease, the active and the remission/inactive states.

METHODS

This study was conducted on 30 SLE patients and 23 healthy controls. The oxidative burst in neutrophils of SLE patients and controls was triggered by fMLP and TPA, while reactive oxygen species (ROS) production was evaluated using a chemiluminescence assay. Oxidative damages in neutrophils were assessed by measuring Free thiol groups level and carbonyl groups, as protein oxidative markers. The malondialdehyde (MDA) level informed about the lipid peroxidation (LPO) and the catalase activity indicated the antioxidant enzymatic activity.

RESULT

Compared to controls, SLE patients exhibited a significantly increased level of ROS production concomitantly to a decreased response time. Their Neutrophils were characterized by a decreased level of MDA and high levels of protein oxidation as evidenced by increased carbonyl groups and decreased SH levels. The catalase activity was higher in SLE patients' neutrophils compared to controls. When patients were clustered according to the disease activity, PMN of patients in active phase showed, paradoxically, a lower ROS production and exhibited higher oxidative damages than the inactive group.

CONCLUSION

Our results highlight an altered behavior of LES patients derived PMN particularly in the active phase of the disease. The evaluation of the redox status including the rate of ROS production could be a biological marker to follow the activity of the disease.

Toll-like receptor activation in the pathogenesis of lupus nephritis

The pathogenesis of systemic lupus erythematosus (SLE) and lupus nephritis is complex but no longer enigmatic. Much progress has been made to on the polygenetic origin of lupus in identifying gene variants that permit the loss of tolerance against nuclear autoantigens. Along the same line in about 50% of lupus patients additional genetic weaknesses promote immune complex glomerulonephritis and filtration barrier dysfunction. Here we briefly summarize the pathogenesis of SLE with a focus on loss of tolerance and the role of toll-like receptors in the "pseudo"-antiviral immunity concept of systemic lupus. In addition, we discuss the local role of Toll-like receptors in intrarenal inflammation and kidney remodeling.

Intricate interactions of obesity, intestinal flora and Toll-like receptors

The rapidly increasing incidence of obesity has resulted in a severe public problem globally. Obesity is associated with subclinical inflammation, causing elevated levels of inflammatory cytokines, as well as disorders of the immune function, which are involved in the dysfunction of intestinal flora. Intestinal flora maintains a dynamic equilibrium with intestinal mucosal immunity. Obesity-related inflammation is mainly trigged by endoplasmic reticulum stress, Toll-like receptor 4 (TLR4) activation and changes of gut flora. Among them, TLR4 plays a central role in sensing intestinal pathogens and inducing mucosal immunity. On the other hand, metabolism, genetics, gut flora and immune state are integrally regulating the TLR function. In the present paper we explore the intricate interactions of obesity, intestinal flora and TLRs, in order to find novel targets for the treatment of obesity.