Model Of Nephritis Research Articles

Heymann nephritis in Lewis rats.

Human membranous nephritis is a major cause of end-stage kidney disease. Active Heymann nephritis (HN) is an auto-immune model of membranous nephritis induced in Lewis rats by immunization with a crude renal tubular antigen (Fx1A) or megalin (gp330). The pathogenesis of HN is through the binding of anti-Fx1A autoantibodies to the auto-antigen expressed on glomerular epithelial cells, resulting in severe glomerular injury and proteinuria. The pathological features of HN include immune deposits in glomeruli and infiltration of glomeruli and the tubulointerstitium by macrophages and T cells. This unit describes the method of the preparation of Fx1A and the induction of HN in Lewis rats by immunization with Fx1A.

Membranous Nephropathy: The Journey Continues …

Membranous Nephropathy: The Journey Continues …

S100A8/A9 (Calprotectin) Is Critical for Development of Glomerulonephritis and Promotes Inflammatory Leukocyte–Renal Cell Interactions

Glomerulonephritis is a common cause of end-stage renal disease. Infiltrating leukocytes interacting with renal cells play a critical role during the initiation and progression of glomerulonephritis, but the exact mechanisms are not clearly defined. By using the murine model of nephrotoxic nephritis, we investigated the role of S100A8/A9 [myeloid-related protein (MRP) 8/14, calprotectin] in promoting glomerulonephritis. In nephrotoxic nephritis, wild-type (WT) mice with glomerulonephritis have elevated serum levels of S100A8/A9, whereas mice deficient in MRP14 (S100a9(-/-)), and hence S100A8/A9, are significantly protected from disease. By using bone marrow transplants, we showed that MRP14 deficiency is required in both the hemopoietic and intrinsic cells for the protective effect. In vitro, both the WT bone marrow-derived macrophages and renal mesangial cells stimulated with S100A8/A9 secrete IL-6, CXCL1, and tumor necrosis factor α; however, Mrp14(-/-) cells exhibit significantly blunted proinflammatory responses. The interaction of WT bone marrow-derived macrophages with renal microvascular endothelial cells results in increased levels of monocyte chemotactic protein 1, IL-8, and IL-6 cytokines, which is attenuated in Mrp14(-/-) bone marrow-derived macrophages. Data shows that S100A8/A9 plays a critical role during glomerulonephritis, exerting and amplifying autocrine and paracrine proinflammatory effects on bone marrow-derived macrophages, renal endothelial cells, and mesangial cells. Therefore, complete S100A8/A9 blockade may be a new therapeutic target in glomerulonephritis.

Reagent- and separation-free measurements of urine creatinine concentration using stamping surface enhanced Raman scattering (S-SERS).

We report a novel reagent- and separation-free method for urine creatinine concentration measurement using stamping surface enhanced Raman scattering (S-SERS) technique with nanoporous gold disk (NPGD) plasmonic substrates, a label-free, multiplexed molecular sensing and imaging technique recently developed by us. The performance of this new technology is evaluated by the detection and quantification of creatinine spiked in three different liquids: creatinine in water, mixture of creatinine and urea in water, and creatinine in artificial urine within physiologically relevant concentration ranges. Moreover, the potential application of our method is demonstrated by creatinine concentration measurements in urine samples collected from a mouse model of nephritis. The limit of detection of creatinine was 13.2 nM (0.15 µg/dl) and 0.68 mg/dl in water and urine, respectively. Our method would provide an alternative tool for rapid, cost-effective, and reliable urine analysis for non-invasive diagnosis and monitoring of renal function.

Inflammation-Induced IL-6 Functions as a Natural Brake on Macrophages and Limits GN.

IL-6 can mediate proinflammatory effects, and IL-6 receptor (IL-6R) blockade as a treatment for inflammatory diseases has entered clinical practice. However, opposing effects of IL-6 have been observed in models of GN. Although IL-6 is proinflammatory in murine lupus nephritis, protective effects have been observed for IL-6 in the nephrotoxic nephritis (NTN) model of acute crescentic GN. In light of the potential dangers of IL-6-directed treatment, we studied the mechanisms underlying the contradictory findings in GN. IL-6 can signal through the membrane-bound IL-6R, which is expressed only on hepatocytes and certain leukocytes (classic), or through the soluble IL-6R, which binds the ubiquitously expressed gp130 (alternative). Preemptive treatment of mice with anti-IL-6R or anti-IL-6 worsened NTN, whereas selective blockade of alternative IL-6 signaling by the fusion protein sgp130Fc did not. FACS analysis of mouse spleen cells revealed proinflammatory macrophages express the highest levels of IL-6Rα, and in vitro treatment with IL-6 blocked macrophage proliferation. Furthermore, proinflammatory macrophages were expanded during inflammation in IL-6(-/-) mice. Late application of anti-IL-6 after establishment of adaptive nephritogenic immunity was sufficient to aggravate NTN within 2.5 days, a period when macrophages are active. Finally, NTN was aggravated in mice with macrophage-specific impairment of IL-6 classic signaling, coincident with enhanced macrophage proliferation and accumulation in the kidney. Our data thus reveal a novel mechanism in which IL-6-mediated dampening of macrophage activation protects tissues from overshooting immune responses. This finding has important implications for potential IL-6-directed therapies and supports the careful choice of recipient patients and timing.

Anti-inflammatory role of DPP-4 inhibitors in a nondiabetic model of glomerular injury.

Dipeptidyl peptidase (DPP)-4 is an enzyme that cleaves and inactivates incretin hormones capable of stimulating insulin secretion from pancreatic β-cells. DPP-4 inhibitors are now widely used for the treatment of type 2 diabetes. Experimental studies have suggested a renoprotective role of DPP-4 inhibitors in various models of diabetic kidney disease, which may be independent of lowering blood glucose levels. In the present study, we examined the effect of DPP-4 inhibitors in the rat Thy-1 glomerulonephritis model, a nondiabetic glomerular injury model. Rats were injected with OX-7 (1.2 mg/kg iv) and treated with the DPP-4 inhibitor alogliptin (20 mg·kg(-1)·day(-1)) or vehicle for 7 days orally by gavage. Alogliptin significantly reduced the number of CD68-positive inflammatory macrophages in the kidney, which was associated with a nonsignificant tendency to ameliorate glomerular injury and reduce proteinuria. Another DPP-4 inhibitor, anagliptin (300 mg·kg(-1)·day(-1) mixed with food) and a glucagon-like peptide-1 receptor agonist, exendin-4 (10 mg/kg sc), similarly reduced CD68-positive macrophage infiltration to the kidney. Furthermore, ex vivo transmigration assays using peritoneal macrophages revealed that exendin-4, but not alogliptin, dose dependently reduced monocyte chemotactic protein-1-stimulated macrophage infiltration. These data suggest that DPP-4 inhibitors reduced macrophage infiltration directly via glucagon-like peptide-1-dependent signaling in the rat Thy-1 nephritis model and indicate that the control of inflammation by DPP-4 inhibitors is useful for the treatment of nondiabetic kidney disease models.

B7x/B7-H4 modulates the adaptive immune response and ameliorates renal injury in antibody-mediated nephritis.

Kidney disease is one of the leading causes of death in patients with lupus and other autoimmune diseases affecting the kidney, and is associated with deposition of antibodies as well as infiltration of T lymphocytes and macrophages, which are responsible for initiation and/or exacerbation of inflammation and tissue injury. Current treatment options have relatively limited efficacy; therefore, novel targets need to be explored. The co-inhibitory molecule, B7x, a new member of the B7 family expressed predominantly by non-lymphoid tissues, has been shown to inhibit the proliferation, activation and functional responses of CD4 and CD8 T cells. In this study, we found that B7x was expressed by intrinsic renal cells, and was up-regulated upon stimulation with inflammatory triggers. After passive administration of antibodies against glomerular antigens, B7x(-/-) mice developed severe renal injury accompanied by a robust adaptive immune response and kidney up-regulation of inflammatory mediators, as well as local infiltration of T cells and macrophages. Furthermore, macrophages in the spleen of B7x(-/-) mice were polarized to an inflammatory phenotype. Finally, treatment with B7x-immunoglobulin (Ig) in this nephritis model decreased kidney damage and reduced local inflammation. We propose that B7x can modulate kidney damage in autoimmune diseases including lupus nephritis and anti-glomerular basement membrane disease. Thus, B7x mimetics may be a novel therapeutic option for treatment of immune-mediated kidney disease.

Administration of α-Galactosylceramide Improves Adenine-Induced Renal Injury.

Natural killer T (NKT) cells are a subset of lymphocytes that reacts to glycolipids presented by CD1d. Invariant NKT cells (iNKT) correspond to >90% of the total population of NKTs and reacts to α-galactosylceramide (αGalCer). αGalCer promotes a complex mixture of Th1 and Th2 cytokines, as interferon (IFN)-γ and interleukin (IL)-4. NKT cells and IFN-γ are known to participate in some models of renal diseases, but further studies are still necessary to elucidate their mechanisms. The aim of our study was to analyze the participation of iNKT cells in an experimental model of tubule-interstitial nephritis. We used 8-wk-old C57BL/6j, Jα18KO and IFN-γKO mice. They were fed a 0.25% adenine diet for 10 d. Both adenine-fed wild-type (WT) and Jα18KO mice exhibited renal dysfunction, but adenine-fed Jα18KO mice presented higher expression of kidney injury molecule-1 (KIM-1), tumor necrosis factor (TNF)-α and type I collagen. To analyze the role of activated iNKT cells in our model, we administered αGalCer in WT mice during adenine ingestion. After αGalCer injection, we observed a significant reduction in serum creatinine, proinflammatory cytokines and renal fibrosis. However, this improvement in renal function was not observed in IFN-γKO mice after αGalCer treatment and adenine feeding, illustrating that this cytokine plays a role in our model. Our findings may suggest that IFN-γ production is one of the factors contributing to improved renal function after αGalCer administration.

Effects of a Tricaprylin Emulsion on Anti-glomerular Basement Membrane Glomerulonephritis in Rats: In Vivo and in Silico Studies.

Glomerulonephritis (GN) is a set of pathological conditions that result in the destruction of glomeruli and loss of renal function, commonly leading to the development of end-stage renal disease. Current pharmacotherapy is limited to immunosuppressive therapy. In the present study, we found a novel antinephritic effect of a tricaprylin emulsion in the anti-glomerular basement membrane (anti-GBM) GN rat model. We evaluated the treatment in vivo by comparing administration of the emulsion with administration of a casein kinase II (CK2) inhibitor in this rat model, and performed a gene ontology-based microarray analysis to reveal in silico the detailed mechanism of action. Our results showed that administration of the tricaprylin emulsion, or even tricaprylin alone, significantly ameliorated the anti-GBM antibody-induced renal dysfunction in these rats. We believe that tricaprylin is the key active antinephritic component of the emulsion and might be a promising drug for the effective treatment of nephritis. Moreover, with respect to microarray analysis, we developed a generally applicable and rapid method to compare gene expression profile data for multiple models of nephritis and clinical samples from a public domain microarray database.

Establishment and study of passive heymann nephritis model

Objective: To discuss the establishment and stability of passive Heymann nephritis (PHN) in order to provide help for experimental study of membranous nephropathy (MN). Materials and Methods: We used 20 male rats of Sprague-Dawley weighing 120 to 150 g to prepare renal antigen Fx1A based on hypotonic lysis, Ca 2+ aggregation of contaminants and differential centrifugation and used six male New Zealand white rabbits for preparing anti-serum which was injected to SD rats to establish the model in different dosages (1 mL/100 g and 0.5 mL/100 g). The proteinuria of six model making rats were tested after 1st Week and then sacrificed and studied by direct immunofluorescence (IF) for deposition of rat IgG and electron microscopy (EM) in different time (1 st week and 7 th week ) with or without a booster injection. Results: After 7 days (1 st week) of model making, all six rats showed proteinuria (higher than 100 mg/dL). IF and EM study showed a typical pathological features of PHN (MN) but the intensity of IF intensity and electron dense deposits decreased in the rats without a booster injection. Conclusions: A PHN model could be successfully prepared according to the method we reported while a spontaneous remission may appear several weeks after the model making.

Pentoxifylline Attenuates Proteinuria in Anti-Thy1 Glomerulonephritis via Downregulation of Nuclear Factor-κB and Smad2/3 Signaling.

Anti-Thy1 glomerulonephritis is a rat nephritis model closely simulating human mesangial proliferative glomerulonephritis. It affects primarily the mesangium, yet displays substantial proteinuria during the course. This study investigated the molecular signals underlying proteinuria in this disease and the modulation of which by the known antiproteinuric agent, pentoxifylline. Male Wistar rats were randomly divided into a control group and nephritic groups with or without treatment with IMD-0354 (an IκB kinase inhibitor), SB431542 (an activin receptor-like kinase inhibitor) or pentoxifylline. Kidney sections were prepared for histological examinations. Glomeruli were isolated for mRNA and protein analysis. Urine samples were collected for protein and nephrin quantitation. One day after nephritis induction, proteinuria developed together with ultrastructural changes of the podocyte and downregulation of podocyte mRNA and protein expression. These were associated with upregulation of tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-β/activins mRNAs and activation of nuclear factor (NF)-κB p65 and Smad2/3. IMD-0354 attenuated proteinuria on d 1, whereas SB431542 decreased proteinuria on d 3 and 5, in association with partial restoration of downregulated podocyte mRNA and protein expression. Pentoxifylline attenuated proteinuria and nephrinuria through the course, plus inhibition of p-NF-κB p65 (d 1) and p-Smad2/3 (d 5) and partial reversal of downregulated podocyte mRNA and protein. Our data show that the pathogenesis of proteinuria in anti-Thy1 glomerulonephritis involves TNF-α and TGF-β/activin pathways, and the evolution of this process can be attenuated by pentoxifylline via downregulation of NF-κB and Smad signals and restoration of the podocyte component of the glomerular filtration barrier.

Podocyte biology: Differentiation of parietal epithelial cells into podocytes.

A new study demonstrates that knockdown of miR-193a in human parietal epithelial cells induces their differentiation into podocytes. Inhibition of miR-193a in a model of nephrotoxic nephritis resulted in reduced proteinuria and crescent formation. These data suggest that promoting differentiation of parietal progenitors into podocytes has potential therapeutic relevance.

Deficiency of Fibroblast Growth Factor-Inducible 14 (Fn14) Preserves the Filtration Barrier and Ameliorates Lupus Nephritis

TNF ligand superfamily member 12, also known as TNF-related weak inducer of apoptosis (TWEAK), acts through its receptor, fibroblast growth factor-inducible 14 (Fn14), to mediate several key pathologic processes involved in tissue injury relating to lupus nephritis. To explore the potential for renal protection in lupus nephritis by targeting this pathway, we introduced the Fn14 null allele into the MRL-lpr/lpr lupus mouse strain. At 26-38 weeks of age, female Fn14-knockout MRL-lpr/lpr mice had significantly lower levels of proteinuria compared with female wild-type MRL-lpr/lpr mice. Furthermore, Fn14-knockout mice had significantly improved renal histopathology accompanied by attenuated glomerular and tubulointerstitial inflammation. There was a significant reduction in glomerular Ig deposition in Fn14-knockout mice, despite no detectable differences in either serum levels of antibodies or splenic immune cell subsets. Notably, we found that the Fn14-knockout mice displayed substantial preservation of podocytes in glomeruli and that TWEAK signaling directly damaged barrier function and increased filtration through podocyte and glomerular endothelial cell monolayers. Our results show that deficiency of the Fn14 receptor significantly improves renal disease in a spontaneous lupus nephritis model through prevention of the direct injurious effects of TWEAK on the filtration barrier and/or modulation of cytokine production by resident kidney cells. Thus, blocking the TWEAK/Fn14 axis may be a novel therapeutic intervention in immune-mediated proliferative GN.

FHL2-driven molecular network mediated Septin2 knockdown inducing apoptosis in mesangial cell.

The apoptosis of mesangial cells (MCs) plays a critical role in the pathological progress of MesPGN. Septin2, a filamentous GTPase, is implicated in the apoptotic progress of MCs in the rat MesPGN model. However, the molecular mechanism of SEPT2 in MCs apoptosis is not clear. Here, we present the FHL2-driven molecular network as the main mechanism of SEPT2-mediated rat primary MCs apoptosis. First, we proved that the expression of FHL2 and Septin2 were closely related with MCs apoptosis in anti-Thy1 nephritis model. Then, it was found that FHL2 was a new interaction protein of Septin2 and Septin2 knockdown could induce MC apoptosis by FHL2-mediatied signal pathways including p-ERK1 and p-AKT. We applied label-Free quantitative proteomics to identify the mechanism of Septin2/FHL2-regulated apoptosis. Bioinformatics analysis revealed that FHL2-driven molecular network composed of biological functions including glycolysis, oxidative stress, ribonucleotide metabolism, actin cytoskeleton regulation, and signaling pathway, was the main mechanism of SETP2-mediated apoptosis. Furthermore, we showed that the effect of Septin2 knockdown on MC apoptosis could be alleviated by the overexpression of FHL2. Overall, this study illustrated the FHL2-driven molecular network controlling SEPT2-mediated apoptosis in MCs and their potential roles in mesangial proliferative nephritis.

The effect of juvenile systemic lupus erythematosus serum activated macrophages on a lupus nephritis model

Podocytes are kidney cells residing in the Bowman’s capsule wrapping around the capillaries of the glomerulus; they form a seal, which contributes greatly to the glomerular filtration barrier (GFB). Their function is highly linked to their morphology, alterations result in loss of integrity of the podocyte seal which can allow the diffusion of proteins from the circulation resulting in proteinuria. A human podocyte cell-line with human-monocyte derived macrophages can be used to create an in vitro model of lupus nephritis (LN). Using this model, it is known that the chemokine monocyte chemoattractant protein 1 (MCP-1) may be released, which has also been identified as a biomarker of the active disease. MCP-1 causes recruitment of pro-inflammatory cells to the kidney. Incubation of this model with JSLE serum may mediate an inflammatory response representing a biologically relevant environment and subsequently provide a clearer understanding into the development of LN.

Structure and function of renal macrophages and dendritic cells from lupus-prone mice.

To characterize renal macrophages and dendritic cells (DCs) in 2 murine models of lupus nephritis. We used a bead-based enrichment step followed by cell sorting to isolate populations of interest from young mice and nephritic mice. Cell morphology was examined by microscopy. Arginase and nitrite production was examined using biochemical assays. The antigen-presenting functions of the cells were determined using mixed lymphocyte reactions. Selected cytokine, chemokine, and Toll-like receptor (TLR) profiles were examined using real-time quantitative polymerase chain reaction. We identified 2 populations of macrophages and 3 populations of DCs in both of our murine models of lupus (NZB/NZW and [NZW × BXSB]F1 mice). F4/80(high) macrophages, which were resident in normal kidneys and found to be increased in number during nephritis, did not produce either arginase or nitrite upon cytokine stimulation and acquired a mixed proinflammatory and antiinflammatory functional phenotype during nephritis that resembles the constitutively activated phenotype of gut F4/80(high) macrophages. The various cell types differed in their expression of chemokine receptors and TLRs, consistent with variability in their renal location. Resident renal CD103+ DCs were the best antigen-presenting cells and could easily be distinguished from CD11c(high) myeloid DCs that accumulated in large numbers during nephritis. Our study highlights the heterogeneity of the macrophage/DC infiltrate in chronic lupus nephritis and provides an initial phenotypic and functional analysis of the different cellular components that can now be used to define the role of each cell subset in nephritis progression or amelioration. Of note, the dominant macrophage population that accumulates during nephritis has an acquired phenotype that is neither M1 nor M2 and may reflect failure of resolution of inflammation.

CD354 in lupus nephritis (THER5P.825)

Abstract CD354, Triggering Receptor of Myeloid Cells -1 (TREM-1), is a potent amplifier of myeloid immune responses. Our goal is to determine the expression and function of TREM-1 in lupus nephritis. We used an anti-glomerular basement membrane antibody-induced nephritis (anti-GBM) model, which shares pathologic features with lupus nephritis (LN). 5 days after mice were sensitized with rabbit IgG in adjuvant, the mice received anti-GBM serum i.v. to induce disease. Anti-GBM treated 129x1/svJ mice developed severe nephritis and B6 mice did not. Anti-GBM disease induced elevated urine sTREM-1 levels in 129x1/svJ (dys 7-21) compared to B6 mice. TREM -1 blockade with an inhibitory peptide ameliorated renal inflammation compared to control peptide. TREM-1 blockade inhibited proteinuria and renal disease as measured by GN class, severity of tubulo-interstitial disease, crescent formation, and inflammatory cell infiltrates. Elevated sTREM-1 levels were detected in serum of spontaneous LN models and in their renal biopsies. Elevated TREM-1 levels were detected in serum of lupus nephritis patients and in SLE renal biopsies. We found that elevated TREM-1 expression in 129x1/svJ mice has importance pathologic consequences. TREM-1 is amenable to therapeutic targeting for nephritis. These studies could be important in understanding of pathogenic mechanisms driving SLE renal disease

Inhibition of TWEAK signaling preserves the glomerular filtration barrier and ameliorates spontaneous murine lupus nephritis (THER6P.845)

Abstract The TNF superfamily member TWEAK acts through its receptor, Fn14, to mediate several key pathological processes known to be involved in lupus nephritis. To explore the potential for renal protection by targeting this pathway, we introduced the Fn14 null allele into the MRL/lpr lupus mouse strain. At 26 to 38 weeks of age, female MRL/lpr Fn14 knockout (KO) mice (backcross #8) had significantly lower levels of proteinuria, BUN, and creatinine as compared to Fn14 wild type (WT) mice. Furthermore, Fn14KO mice had significantly improved renal pathology, accompanied by attenuated glomerular and tubulointerstitial inflammation and less glomerular immune deposits. There were no detectable differences between the strains in either serum autoantibody levels or in splenic immune cell subsets, although less lymphadenopathy was observed in Fn14KO mice. Importantly, Fn14KO mice displayed substantial preservation of podocytes in kidney glomeruli. Moreover, we demonstrated that TWEAK signaling via Fn14 directly damaged the integrity of the glomerular filtration barrier through effects on both podocytes and glomerular endothelial cells. Inhibition of TWEAK signaling due to deficiency of the Fn14 receptor significantly improves renal disease in a spontaneous lupus nephritis model, likely through prevention of the direct injurious effects of TWEAK on the filtration barrier. Thus, blocking the TWEAK/Fn14 axis is a novel therapeutic target in immune-mediated proliferative glomerulonephritis.

Small molecule agonists of CD11b/CD18 reduce leukocyte activation and recruitment to promote kidney allograft survival (TRAN3P.909)

Abstract Allograft rejection in kidney transplantation is associated with leukocyte infiltration, including myeloid cells expressing β2 integrin CD11b/CD18. We reported that activation of CD11b/CD18 by a small molecule compound, leukadherin-1 (LA1), increases leukocyte cell adhesion to the inflamed endothelium, prevents transmigration and inhibits leukocyte tissue recruitment resulting in improved kidney function in a murine nephritis model. Here we test whether LA1 mediated activation of CD11b/CD18 enhances kidney allograft survival in a mouse model of fully MHC-mismatched orthotopic kidney transplant, where C57BL/6J (H-2b) recipients received a kidney allograft from Balb/c mice (H-2d). Control recipients were treated daily with cyclosporine (CsA) for 2 weeks, while the test group received standard CsA therapy and daily LA1 injections during week 1 and alternate days during weeks 2-8. Renal allograft rejection was considered when mice displayed signs of ill health and high serum creatinine levels. Combination therapy reduced leukocyte infiltration and neointimal hyperplasia and increased graft survival from 48.5% (CsA only) to 100% (CsA and LA1) on day 60. At week 5, CsA treated controls had serum creatinine values of 0.6 mg/dl while LA1 and CsA treated mice had baseline values of 0.2 mg/dl. These findings indicate a crucial role for CD11b/CD18 in the control of leukocyte migration to the transplanted kidney and identify leukadherins as therapeutic agents for renal transplantation.

R-268712, an orally active transforming growth factor-β type I receptor inhibitor, prevents glomerular sclerosis in a Thy1 nephritis model

R-268712 is a novel and specific inhibitor of activin receptor-like kinase 5 (ALK5), a transforming growth factor β (TGF-β) type I receptor. Evaluation of in vitro inhibition indicated that R-268712 is a potent and selective inhibitor of ALK5 with an IC50 of 2.5nM, an approximately 5000-fold more selectivity for ALK5 than p38 mitogen-activated protein kinase (MAPK). Oral administration of R-268712 at doses of 1, 3 and 10mg/kg also inhibited the development of renal fibrosis in a dose-dependent manner in a unilateral ureteral obstruction (UUO) model. Additionally, we evaluated the efficacy of R-268712 in a heminephrectomized anti-Thy1 glomerulonephritis model at doses of 0.3 and 1mg/kg. R-268712 reduced proteinuria and glomerulosclerosis significantly with improvement of renal function. Collectively, these results suggested that R-268712 and other ALK5 inhibitors could suppress glomerulonephritis as well as glomerulosclerosis by an inhibitory mechanism that involves suppression of TGF-β signaling.