Heymann Nephritis Research Articles

The therapeutic effects of human embryonic stem cells-derived immunity-and-matrix regulatory cells on membranous nephropathy

BackgroundPrimary membranous nephropathy (MN) is a kidney-specific autoimmune disease. Human embryonic stem cells-derived immunity-and-matrix regulatory cells (hESC-IMRCs) have immunoregulatory functions. We hypothesized that hESC-IMRCs might have therapeutic effects on MN and be a potential treatment in clinical practice.MethodsRats of Heymann nephritis were injected with sheep anti-rat Fx1A serum. hESC-IMRCs were intravenously administrated upon the detection of proteinuria, with 6 × 106 cells (high-dose) or 3 × 106 cells (low-dose) in 1 ml every other day. Splenocytes and IMRCs were co-cultured at different times and ratios. Cell types and cytokines were detected by flow cytometry and enzyme-linked immunosorbent assay.ResultsThe urinary protein of rats with Heymann nephritis was reduced remarkably to a level comparable to negative controls, in both low-dose (45.6 vs. 282.3 mg/d, P < 0.001) and high-dose (35.2 vs. 282.3 mg/d, P < 0.001) hESC-IMRC treatment groups. IgG and C3 deposit, glomerular basement membrane thickness and foot process effacement were alleviated and the reduced podocin was recovered in the kidneys. The proportions of CD4 + CD25 + T cells in circulation and spleen were increased, and the circulating level of IL-10 was increased, after IMRC interventions. IL-17 and TNF-α were reduced after IMRCs treatments. IL-10 increased remarkably in the co-culture supernatant of lymphocytes and IMRCs at 48 h with ratio 10:1.ConclusionsThe intravenously delivered hESC-IMRCs alleviated proteinuria and kidney injuries of Heymann nephritis, by their immunosuppressive functions through regulatory T cells and IL-10. These pre-clinical results indicate that IMRCs worth careful consideration for human trials in the treatment of MN.

POS-042 C3d-Directed Factor H Targeting Delivers Potent and Durable Complement Inhibition and Disease-Modifying Efficacy In Kidney and Skin Without Inhibiting Systemic Complement

POS-042 C3d-Directed Factor H Targeting Delivers Potent and Durable Complement Inhibition and Disease-Modifying Efficacy In Kidney and Skin Without Inhibiting Systemic Complement

Evaluation of renal injury and function biomarkers, including symmetric dimethylarginine (SDMA), in the rat passive Heymann nephritis (PHN) model

Symmetric dimethylarginine (SDMA) is a serum biomarker of excretory renal function which consistently correlates with glomerular filtration rate (GFR) across multiple species including rats, dogs, and humans. In human and veterinary clinical settings SDMA demonstrates enhanced sensitivity for detection of declining renal function as compared to other serum biomarkers, but application in preclinical study designs thus far has been limited. The purpose of this study was to determine the performance of serum SDMA in a rat passive Heyman nephritis model of glomerulopathy. In addition to SDMA other biomarkers of excretory renal function were measured including serum creatinine (sCr), blood urea nitrogen (BUN), and cystatin C along with creatinine clearance. Urinary renal biomarkers including microalbumin (μALB), clusterin (CLU), cystatin C, kidney injury marker-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and osteopontin (OPN) were also measured. PHN was induced using commercial sheep anti-Fx1A serum. Tissue, serum, and urine were collected from groups of control and anti-Fx1A-treated animals for biomarker evaluation, hematology, urinalysis, serum biochemistry, and histologic examination of kidney. Over the course of a 28-day study, concentrations of the urinary biomarkers μALB, CLU, cystatin C, NGAL, KIM-1 and the serum biomarker cystatin C increased significantly in anti-Fx1A-treated rats as compared to controls but no significant increase in serum SDMA, sCr, BUN, or creatinine clearance were noted in anti-Fx1A-treated rats. Given lack of direct GFR measurement or significant change in the renal function biomarkers sCr, BUN, and creatinine clearance, it is unclear if GFR differed significantly between control and anti-Fx1A-treated rats in this study, though urinary biomarkers and histopathologic findings supported renal injury in anti-Fx1A-treated rats over the time course investigated. This study is among the first to investigate serum SDMA in a rat model relevant to preclinical safety assessment and serves to inform future experimental designs and biomarker selection when evaluation of glomerular injury is of priority.

The Ameliorative Effect of Mahuang Fuzi and Shenzhuo Decoction on Membranous Nephropathy of Rodent Model is Associated With Autophagy and Wnt/β-Catenin Pathway.

The increased incidence of membranous nephropathy (MN) has made it the most common pathological type of primary nephrotic syndrome in adults in China. According to the theory of Traditional Chinese Medicine (TCM), Mahuang Fuzi (Chinese ephedra and Radix Aconiti Lateralis Preparata) and Shenzhuo Decoction (MFSD) could be used to treat such diseases. We treated patients of MN with MFSD, and observed comparable efficacy to glucocorticoid and/or immunosuppressants. In this study, we observed the therapeutic effect of MFSD on the rat model of passive Heymann nephritis (PHN), a classical MN model. Our results showed that MFSD treatment significantly reduced urinary protein level and podocyte injury in PHN rats, and correspondingly improved renal pathology, with the improvement effect on MN comparable to that of Cyclosporine A (CsA) alone. To explore the potential therapeutical mechanism of MFSD, the main chemical components of MFSD were determined by High-performance liquid chromatography-mass spectrometry (HPLC-MS). There were about 30 active components of MFSD. Next, based on network pharmacology methods, we screened related targets of MSFD on MN, which provided a preliminary understanding of the MFSD bioactive compounds. The clustering analysis showed that its active site might be in the autophagy-related protein and Wnt/β-catenin pathway, which was related to podocyte injury. Finally, we observed an improvement in renal autophagy and a down-regulation of the Wnt/β-catenin pathway after MSFD treatment in a PHN rat model. According to this study, autophagy and Wnt/β-catenin pathway may be potential targets for MFSD in the treatment of MN.

Complement induces podocyte pyroptosis in membranous nephropathy by mediating mitochondrial dysfunction

Podocyte damage mediated by in situ complement activation in the glomeruli is a key factor in the pathogenesis of membranous nephropathy (MN), but the molecular mechanism has not been fully elucidated. Pyroptosis is a special type of programmed cell death, mediate inflammatory response and induce tissue injury. However, it is not clear whether pyroptosis is involved in the development and progression of MN. Here, we report that pyroptosis plays an important role in promoting podocyte injury in MN. We first observed the occurrence of pyroptosis in the kidneys of MN patients and validated that complement stimulation triggered pyroptosis in podocytes and that inhibiting pyroptosis reversed complement-induced podocyte damage in vitro. In addition, stimulation of complement caused mitochondrial depolarization and reactive oxygen species (ROS) production in podocytes, and inhibition of ROS reversed complement-induced pyroptosis in podocytes. Interestingly, inhibition of pyroptosis in turn partially alleviated these effects. Furthermore, we also found the involvement of pyroptosis in the kidneys of passive Heymann nephritis (PHN) rats, and inhibitors of pyroptosis-related molecules relieved PHN-induced kidney damage in vivo. Our findings demonstrate that pyroptosis plays a critical role in complement-induced podocyte damage in MN and mitochondrial dysfunction is an important mechanism underlying this process. It provides new insight that pyroptosis may serve as a novel therapeutic target for MN treatment in future studies.

POS-384 EFFECT OF ANG-3070 IN THE PASSIVE HEYMANN NEPHRITIS RAT MODEL OF PRIMARY PROTEINURIC KIDNEY DISEASE

Primary proteinuric kidney diseases (PPKD) as a group are an important cause of end-stage kidney disease (ESKD). Many receptor tyrosine kinases, including platelet-derived growth factor receptor (PDGFR), contribute to the progression of PPKDs to ESKD. ANG-3070 is a novel and proprietary inhibitor of multiple tyrosine kinases including PDGFR. This study evaluated the effects of ANG-3070 in a passive Heymann nephritis (PHN) rat model of membranous glomerulopathy.

POS-396 RHODOJAPONIN VI AMELIORATES PODOCYTE INJURY BY REGULATING MDM2/NOTCH1 PATHWAY IN RAT EXPERIMENTAL MEMBRANOUS NEPHROPATHY

Rhodojaponin VI (R-VI) is the key compound of Rhododendron molle G. Don (Ericaceae) (RM) with effective clinical application in rheumatoid arthritis and chronic glomerulonephritis. In our study, we tried to explore the effect of R-VI on the rat model of passive heymann nephritis (PHN).

Treatment of Membranous Nephropathy by Disulfiram through Inhibition of Podocyte Pyroptosis

Introduction: Membranous nephropathy (MN) is a common chronic kidney disease in adults and a major challenge of clinical practice for its treatment. Despite major advances, since the discovery of the phospholipase A2 receptor as the major autoantigen of podocytes in MN, the mechanisms leading to glomerular damage remain elusive. Pyroptosis, a newly discovered type of programed necrotic cell death mainly mediated by gasdermin, was found to be responsible for podocyte injury in MN in our recent work. Objectives: The aim of this study was to explore the therapeutic effect of an FDA-approved drug, disulfiram (DSF), in the treatment of MN by inhibiting pyroptosis. Methods and Results: DSF significantly alleviated C3a/C5a-induced podocyte injury in vitro and renal lesions in passive Heymann nephritis (PHN) rats, as reflected by the decreased percentage of propidium iodide staining podocytes, decreased lactate dehydrogenase release from cultured podocytes and improvement in 24-h urine protein, serum albumin, serum creatinine, abnormal alterations of podocyte injury markers Desmin and WT-1 and podocyte foot process fusion in PHN rats. The protective effect of DSF on podocyte injury in vitro and in vivo can be ascribed to its inhibition of the activation and membrane translocation of the pyroptosis executor gasdermin D (GSDMD) in podocytes. DSF also inhibited the increase and activation of the pyroptosis signaling pathway NLRP3-ASC-Caspase-1/IL-18/GSDMD in C3a/C5a-treated podocytes and renal tissue of PHN rats. Conclusion: DSF is a potential drug for MN treatment, and its clinical application needs to be further investigated.

Structural modulation of gut microbiota during alleviation of experimental passive Heymann nephritis in rats by a traditional Chinese herbal formula.

Jianpi-Qushi-Heluo formula (JQHF) has been used to treat idiopathic membranous nephropathy (IMN) in hospitals for many years. Elucidating the protective effect and exploring the potential mechanism of JQHF against IMN. Passive Heymann nephritis (PHN) was induced in rats by a single tail vein injection of anti-Fx1A antiserum. Then, the animals were treated with JQHF at 16.2g/kg or 32.4g/kg, with benzepril (10mg/kg) as a positive control. Renal function was evaluated by biochemical measurements and pathological testing. Fecal samples were collected before and after treatment to analyze the gut microbiota composition by shotgun whole metagenome sequencing. JQHF exhibited potent efficacy in ameliorating PHN at both doses, as revealed by decreasing the deposition of IgG and C5b-9, relieving podocyte injury, and reducing glomerular and tubular cell apoptosis. The lower dose was corresponding to the clinical dosage and showed better therapeutic effects than the higher dose. Metagenomic analysis showed that gavage with 16.2g/kg of JQHF shifted the structure of the gut microbiota in PHN rats and significantly increased the relative abundances of Prevotella copri, Lactobacillus vaginalis and Subdoligranulum variabile. Particularly, S. variabile was strongly negatively correlated with serum levels of TC and TG, the deposition of IgG and C5b-9, and apoptosis of glomerular cells. The JQHF is an effective agent for the treatment of experimental PHN. The PHN-allevating effect of JQHF is associated with specific alternation of gut microbiota.

Sanqi Oral Solution Mitigates Proteinuria in Rat Passive Heymann Nephritis and Blocks Podocyte Apoptosis via Nrf2/HO-1 Pathway.

Idiopathic membranous nephropathy (IMN) is the most common pathological type in adult nephrotic syndrome where podocyte apoptosis was found to mediate the development of proteinuria. Sanqi oral solution (SQ), an effective Chinese herbal preparation clinically used in treatment of IMN for decades, plays an important role in reducing proteinuria, but the underlying mechanisms have not been fully elucidated yet. The current study tested the hypothesis that SQ directly lessens proteinuria in IMN by reducing podocyte apoptosis. To investigate the effects of SQ, we established the experimental passive Heymann nephritis (PHN) rat model induced by anti-Fx1A antiserum in vivo and doxorubicin hydrochloride (ADR)-injured apoptotic podocyte model in vitro. SQ intervention dramatically reduced the level of proteinuria, together with the rat anti-rabbit IgG antibodies, complement C3, and C5b-9 deposition in glomerulus of PHN rats, accompanied by an elevation of serum albumin. Protein expression of synaptopodin, marker of podocyte injury, restored after SQ administration, whereas the electron microscopic analysis indicated that fusion of foot processes, and the pachynsis of glomerular basement membrane was markedly diminished. Further studies showed that SQ treatment could significantly inhibit podocyte apoptosis in PHN rats and ADR-injured podocytes, and protein levels of Cleaved Caspase-3 or the ratio of Bax/Bcl-2 were significantly decreased with SQ treatment in vivo or in vitro. Moreover, we found that the nuclear factor erythroid 2–related factor-2/heme oxygenase 1 (Nrf2/HO-1) pathway mediated the anti-apoptosis effective of SQ in podocyte. Thus, SQ mitigates podocyte apoptosis and proteinuria in PHN rats via the Nrf2/HO-1 pathway.

Evaluation of ultrastructural alterations of glomerular basement membrane and podocytes in glomeruli by low-vacuum scanning electron microscopy

BackgroundLow-vacuum scanning electron microscopy (LV-SEM) is applied to diagnostic renal pathology.MethodsTo demonstrate the usefulness of LV-SEM and to clarify the optimal conditions of pathology samples, we investigated the alterations of glomerular basement membrane (GBM) and podocytes in control and experimental active Heymann nephritis (AHN) rats by LV-SEM.ResultsOn week 15 following induction of AHN, spike formation on GBM with diffuse deposition of IgG and C3 developed. Using LV-SEM, diffuse crater-like protrusions were clearly noted three-dimensionally (3D) on surface of GBM in the same specimens of light microscopy (LM) and immunofluorescence (IF) studies only after removal coverslips or further adding periodic acid-silver methenamine (PAM) staining. These 3D ultrastructural findings of GBM surface could be detected in PAM-stained specimens by LV-SEM, although true GBM surface findings could not be obtained in acellular glomeruli, because some subepithelial deposits remained on surface of GBM. Adequate thickness was 1.5–5 μm for 10% formalin-fixed paraffin-embedded (FFPE) and 5–10 μm for the unfixed frozen sections. The foot processes and their effacement of podocytes could be observed by LV-SEM using 10%FFPE specimens with platinum blue (Pt-blue) staining or double staining of PAM and Pt-blue. These findings were obtained more large areas in 2.5% glutaraldehyde-fixed paraffin-embedded (2.5%GFPE) specimens.ConclusionOur findings suggest that LV-SEM is a useful assessment tool for evaluating the alterations of GBM and podocytes in renal pathology using routine LM and IF specimens, as well as 2.5%GFPE specimens.

POS-453 MC1R SIGNALING PROTECTS AGAINST EXPERIMENTAL MEMBRANOUS NEPHROPATHY AND MEDIATES THE BENEFICIAL EFFECT OF MELANOCORTIN THERAPY VIA REGULATION OF HUMORAL IMMUNE RESPONSES

Clinical evidence suggests that melanocortin therapy by using adrenocorticotropin (ACTH) is effective in inducing remission of proteinuria in patients with idiopathic membranous nephropathy (MN) and even in those resistant to steroids or other immunosuppressants. Likewise, in passive Heymann's nephritis (PHN), a rat model of MN, ACTH and other non-steroidogenic melanocortins are able to ameliorate glomerular injury and proteinuria. However, the type of melanocortin receptor (MCR) mediating this beneficial effect as well as the underlying mechanism remains controversial.

Tetrandrine may treat membranous glomerulopathy via P13K/Akt signaling pathway regulation: therapeutic mechanism validation using Heymann nephritis rat model

ABSTRACT Membranous glomerulopathy (MGN) is an autoimmune kidney disease that is the primary cause of nephrotic syndrome (NS) in adults. Tetrandrine, a bisbenzylisoquinoline alkaloid, is known to have numerous pharmacological effects. In this study, network pharmacology analysis and experimental validation were conducted to analyze the mechanisms by which tetrandrine functions as a therapeutic intervention for MGN. A systematic network pharmacology method was applied to identify potential targets and determine the therapeutic mechanism of tetrandrine in MGN treatment. A Heymann nephritis (HN) rat model was developed to assess the therapeutic effects of tetrandrine on NS and validate the predicted molecular mechanisms. We obtained 86 potential targets of tetrandrine for the treatment of NS. In vivo experiments showed that tetrandrine could reduce the 24-h urine protein content, decrease glomerular basement membrane proliferation, and significantly decrease thylakoid stroma and cell proliferation in the HN rat kidney tissue. Moreover, tetrandrine suppressed kidney cell apoptosis and upregulated the expression of nephrin and podocin in HN model rats. qRT-PCR results revealed that tetrandrine inhibited IL-1β, TNFα, and MCP-1 levels in HN model rats. Western blot results indicated that tetrandrine can protect against MGN via the PI3K/Akt signaling pathway. Thus, by using a combination of network and experimental pharmacology methods, we demonstrate that tetrandrine can treat MGN via the PI3K/Akt signaling pathway and provide novel insights into the mechanisms underlying tetrandrine-mediated management of MGN.

Curcumin Improves the Renal Autophagy in Rat Experimental Membranous Nephropathy via Regulating the PI3K/AKT/mTOR and Nrf2/HO-1 Signaling Pathways.

Membranous nephropathy (MN, also known as membranous glomerulopathy) is one of the many glomerular diseases causing nephrotic syndrome. The literature indicates that autophagy is associated with the homeostasis of podocytes in glomeruli. Curcumin, the main active component in turmeric, has drawn attention for its effective bioactivities against chronic kidney disease. The current study was aimed at assessing the effects of curcumin and exploring the underlying mechanism that mediates autophagy in an animal model of passive Heymann nephritis (PHN) in rats. Passive Heymann nephritis (PHN) was induced in male SD rats by intraperitoneal injection of anti-Fx1A serum. The rats were divided into 3 groups: control (n = 10, normal diet), model group (n = 10, 0.5% sodium carboxymethylcellulose), and curcumin (n = 10, 300 mg/kg/d). The kidney function and oxidative stress indicators were measured using commercial diagnostic kits, and the histomorphology of renal tissues was observed. The number of podocytes was measured by immunohistochemistry. Meanwhile, the autophagosomes in podocyte were analyzed by transmission electron microscopy and the immunofluorescence assay pointing to p62, an autophagic marker. Western blot analyzed the levels of apoptosis, autophagy, PI3K/AKT/mTOR, and Nrf2/HO-1 pathway-associated proteins. The total cholesterol (TC), triglycerides (TG), creatinine (Scr), blood urea nitrogen (BUN), urine volume, and urine albumin of PHN rats were significantly reduced by the administration of curcumin and attenuated renal histomorphological changes in model rats. Meanwhile, curcumin improved the oxidative stress response by decreasing MDA and increasing SOD, GSH, and CAT levels in the kidney of PHN rats. Furthermore, curcumin significantly ameliorated the podocyte loss, along with the fusion, and increased the autophagic vacuoles compared to the PHN control rats. In addition, curcumin downregulated the expression of Bax, Caspase-3, p62, PI3K, p-AKT, and p-mTOR proteins and upregulated the Bcl-2, beclin1, LC3, Nrf2, and HO-1 levels in this animal model. The results provide a scientific basis that curcumin could significantly alleviate the development of MN by inducing autophagy and alleviating renal oxidative stress through the PI3K/AKT/mTOR and Nrf2/HO-1 pathways.

Urinary ERdj3 and mesencephalic astrocyte-derived neutrophic factor identify endoplasmic reticulum stress in glomerular disease

Podocyte injury and endoplasmic reticulum (ER) stress have been implicated in the pathogenesis of various glomerular diseases. ERdj3 (DNAJB11) and mesencephalic astrocyte-derived neurotrophic factor (MANF) are ER chaperones lacking the KDEL motif, and may be secreted extracellularly. Since podocytes reside in the urinary space, we examined if podocyte injury is associated with secretion of KDEL-free ER chaperones from these cells into the urine, and if chaperones in the urine reflect ER stress in glomerulonephritis. In cultured podocytes, ER stress increased ERdj3 and MANF intracellularly and in culture medium, whereas GRP94 (KDEL chaperone) increased only intracellularly. ERdj3 and MANF secretion was blocked by the secretory trafficking inhibitor, brefeldin A. Urinary ERdj3 and MANF increased in rats injected with tunicamycin (in the absence of proteinuria). After induction of passive Heymann nephritis (PHN) and puromycin aminonucleoside nephrosis (PAN), there was an increase in glomerular ER stress, and appearance of ERdj3 and MANF in the urine, coinciding with the onset of proteinuria. Rats with PHN were treated with the chemical chaperone, 4-phenyl butyrate (PBA), starting at the time of disease induction, or after disease was established. In both protocols, 4-PBA reduced proteinuria and urinary ER chaperone secretion, compared with PHN rats treated with saline (control). In conclusion, urinary ERdj3 and MANF reflect glomerular ER stress. 4-PBA protected against complement-mediated podocyte injury and the therapeutic response could be monitored by urinary ERdj3 and MANF.

MO042LNP023: A NOVEL ORAL COMPLEMENT ALTERNATIVE PATHWAY FACTOR B INHIBITOR FOR THE TREATMENT OF GLOMERULAR DISEASE

Abstract Background and Aims The alternative complement pathway (AP) provides the central amplification loop of complement activation and is critically involved in a number of diseases including C3 glomerulopathy (C3G), paroxysmal nocturnal haemoglobinuria (PNH) and atypical haemolytic uremic syndrome. There is also evidence for AP dysregulation in IgA and membranous nephropathies (IgAN, MN). Novartis has developed a highly selective oral low molecular weight inhibitor of complement Factor B, a key AP protease. LNP023 potently blocks AP activation in vitro and in vivo and is efficacious in passive Heymann nephritis in rats, suggesting an important role of the AP in classical-pathway mediated nephropathies. Method LNP023 was tested at increasing single or multiple ascending doses in a Phase I safety, tolerability, pharmacokinetic (PK) and pharmacodynamic study in healthy volunteers. Complement inhibition was measured by the ex vivo Wieslab assay and by quantifying fragment Bb level. Results LNP023 was well tolerated at all doses from 5 mg to 400 mg (single dose) and from 25 mg to 200 mg bid for 14 days (multiple dose). There were no deaths, SAEs or AEs leading to study drug discontinuation in LNP023-treated subjects. LNP023 dose-dependently inhibited the AP complement system. Based on the Wieslab assay, maximal inhibition of AP activity (80% or more) was observed 2 hours after a single dose of 10 mg or higher. The level of Bb decreased until 12 hours post-dose. Approximately 30% to 50% decrease in Bb, relative to baseline, was achieved for subjects receiving a single dose of LNP023 of 5mg or higher. For both assays, the duration of this inhibition was dependent upon the dose administered. Persistent inhibition was obtained in the multiple dose cohorts, the magnitude of inhibition being dose-dependent for the Wieslab assay but not for Bb. PK studies showed rapid drug absorption and no evidence of food effect. The plasma clearance was moderate and the terminal half-life was around 20h. There was an under-proportional dose-exposure relationship. Among other mechanisms, binding to highly expressed target (Factor B) is believed to affect clearance and thus exposure. Following a successful proof of concept Phase 2 study in PNH (data not shown), LNP023 is currently being investigated in three ongoing Phase 2 studies in IgAN (NCT03373461), C3G (NCT03832114) and MN (NCT04154787). The IgAN study has an adaptive seamless design; the first part has recently completed, 46 patients having received 3 months of one of three LNP023 doses or placebo. The study remains blinded; however, similar to the FIH study safety appears excellent, with only one treatment-emergent SAE (inhalation of chlorine gas) and two SAEs in the post-treatment follow-up period. No patient discontinued randomised treatment for any reason. There were no episodes of proven infection with encapsulated bacteria. The independent data safety monitoring committee have endorsed the study proceeding to the second part with the addition of a fourth LNP023 dose and recruitment is ongoing, completion being anticipated in mid-2020.

Advances of the experimental models of idiopathic membranous nephropathy (Review).

Idiopathic membranous nephropathy (IMN) is one of the main types of chronic kidney disease in adults and one of the most common causes of end-stage renal disease. In recent years, the morbidity of IMN among primary glomerular diseases has markedly increased, while the pathogenesis of the disease remains unclear. To address this, a number of experimental models, including Heymann nephritis, anti-thrombospondin type-1 domain-containing 7A antibody-induced IMN, cationic bovine serum albumin, anti-human podocyte antibodies and zymosan-activated serum-induced C5b-9, have been established. This review comprehensively summarized the available animal and cell models for IMN. The limitations and advantages of the current models were discussed and two improved models were introduced to facilitate the selection of an appropriate model for further studies on IMN.

Immunology of membranous nephropathy.

Accounting for about 20 to 50% of cases of primary nephrotic syndrome, membranous nephropathy (MN) is the leading cause of nephrotic syndrome in adults. A rat model created nearly 60 years ago to research the primary MN disorder, Heymann nephritis, has provided us with a plethora of important information. Recently, our knowledge about MN has dramatically progressed. Heymann nephritis and human MN are now known to share a high degree of similarity in pathogenesis. This review summarizes our current understanding of MN pathogenesis while focusing particularly on the immunological aspects.

Urine exosomal ceruloplasmin: a potential early biomarker of underlying kidney disease.

Previously we found that kidney tissue and urinary exosomes from patients of diabetic kidney disease showed high levels of ceruloplasmin (CP). Because CP is an acute-phase protein of kidney origin, it could be an early marker of many other kidney diseases. To investigate this hypothesis, we first measured urine exosomal and kidney expression of CP in non-diabetic chronic kidney disease (CKD) patients (membranous nephropathy, focal segmental glomerulosclerosis, lupus nephritis and IgA nephropathy) followed by a longitudinal study in rat passive Heymann nephritis (PHN), a model of human membranous nephropathy. Urinary exosomes were isolated from urine of patients (and rats) by differential centrifugation. The exosomal extracts were used for measuring CP using ELISA. Kidney expression of CP was evaluated by immune-staining biopsy tissues. Similar techniques were applied in rat PHN model (produced by injection of anti-gp600 antiserum) to analyze urine exosomal and kidney CP. Urine exosomal CP levels were 10-20 times higher in CKD patients than in controls; consistent with this we found high immune-reactive CP localized in tubules and collecting ducts of biopsies of CKD patients. In the PHN model urinary exosomal CP level was significantly higher prior to the onset of proteinuria. Early rise of urine exosomal CP, which preceded proteinuria, correlated with high immunoreactive CP found in rat kidneys at this time. We propose that urine exosomal CP, observed to increase prior to proteinuria, makes it a potential urinary biomarker to diagnose early kidney disease.

Dendritic cell-targeted CD40 DNA vaccine suppresses Th17 and ameliorates progression of experimental autoimmune glomerulonephritis.

The CD40-CD40L costimulatory pathway is critical for T cell activation in autoimmune disease. We have previously found that blocking the CD40-CD40L pathway using a dendritic cell-targeted CD40 DNA (DEC-CD40) vaccine prevented the development of Heymann nephritis. In this study, we explored the effect of a DEC-CD40 vaccine in the treatment of experimental autoimmune glomerulonephritis (EAG), an animal model of human Goodpasture's disease induced by antigen α3IV-NC1. DEC-CD40 vaccine given at week 3 and week 6 after 3IV-NC1 injection reduced kidney structural and functional injury significantly in EAG. DEC-CD40 vaccination suppressed Th17 cell numbers and Th17 immune responses in kidney and spleen, but did not alter Th1 cells number and responses. Serum derived from rats with DEC-CD40 vaccination suppressed Th17 differentiation, but not Th1 differentiation in vitro. Furthermore, B cell activation, driven by Th17 cytokines, was suppressed by serum from rats vaccinated with DEC-CD40. A DNA vaccine encoding CD40 and targeting dendritic cell, ameliorates kidney injury in both early and late stages in EAG rats, indicating DEC-CD40 vaccination has a therapeutic role in EAG. Its effect is associated with the reduction of Th17 differentiation and Th17-mediated B cell activation.