Maho Watanabe

An amplification of IL-10 and TGF-beta in patients with IgG4-related tubulointerstitial nephritis.

BACKGROUND IgG4-related tubulointerstitial nephritis (TIN) shows characteristic serum IgG4 elevation and increased IgG4-positive plasma cells in the renal interstitium, and inclusion of TIN as an IgG4-related systemic disease has been suggested. IgG4 is the rarest IgG subclass and is a Th2-dependent isotype with low affinity for target antigen. Although the pathogenesis of this disease has not been elucidated, positive serum immune complex and hypocomplementemia in some patients with this disease suggest that immune complex mechanisms are involved in the causation of this disease. METHOD We selected 20 cases of histological diagnosed TIN. These cases were etiologically different and included 4 cases of IgG4-related TIN. We extracted RNA from paraffin embedded biopsied kidney and evaluated expression levels of various cytokines for each case by real time PCR. RESULTS Comparison of cytokine production patterns among different disease-associated TINs revealed that IgG4-related TIN exhibited a quite distinct pattern. On the one hand, there was no expression of IL-2, IFN-gamma IL-17 and IL-6, whereas production of IL-4, IL-10 and TGF-beta was, on the other hand, remarkably increased in IgG4-related TIN. CONCLUSION Based on these cytokine production results, Th2 and Treg appear to play a central role in IgG4-related TIN.

Amelioration of diabetic nephropathy in OLETF rats by prostaglandin I(2) analog, beraprost sodium.

Background: Strict control of blood glucose and blood pressure levels sometimes fails to delay the development of diabetic nephropathy, and an effective therapy is not yet available. The present study aimed to examine whether the prostaglandin I2 analog beraprost sodium (BPS) ameliorates diabetic nephropathy in Otsuka Long-Evans Tokushima Fatty (OLETF) rat. Method: Fifty-week-old OLETF rats were divided into three groups according to treatment; 400 μg/kg body weight (BW) BPS, 200 μg/kg BW BPS, and 0.9% saline administration. Kidney histology, index of glomerulosclerosis, and glomerular volume were determined, and urine and serum chemistry were assessed. Results: The values for urine protein excretion and serum blood urea nitrogen in BPS-treated rats were significantly lower than those in untreated rats. In rats treated with 400 μg/kg BW BPS, neither sclerotic changes nor inflammatory cell infiltration were observed. Index of glomerulosclerosis and glomerular volume were also significantly reduced compared with untreated rats. Intriguingly, BPS reduced the level of serum triglyceride. In the glomerulus of treated rats, advanced glycation end product formation and macrophage influx were suppressed in a dose-dependent manner. Conclusion: These findings indicate that BPS has a therapeutic effect on diabetic nephropathy in the OLETF rat, which suggests a potential application of this drug in the treatment of human diabetic nephropathy.

Macrophage impairment produced by Fc receptor gamma deficiency plays a principal role in the development of lipoprotein glomerulopathy in concert with apoE abnormalities

BACKGROUND To obtain a clear understanding of the pathogenesis of lipoprotein glomerulopathy (LPG), we studied the role of the deficiency of Fc receptor gamma chain (FcRγ) for the development of LPG in concert with apolipoprotein E (apoE) abnormalities. METHODS We generated apoE and FcRγ double-knockout (FcRγ/apoE-KO) mice, and subsequently introduced several kinds of human recombinant apoE genes. At 21 days after infection, the mice were sacrificed and histologically examined. Peritoneal macrophages were evaluated for their response to modified lipids. RESULTS In the FcRγ/apoE-KO mice, the human apoE3-injected mice showed the most drastic LPG-like changes, as well as prominent hypertriglyceridemia. Meanwhile, relative to the human apoE3-injected mice, the FcRγ/apoE-KO mice showed greater lipoprotein deposition and less macrophage infiltration into the mesangial area. Moreover, the peritoneal macrophages in the apoE/FcRγ-KO mice were impaired in lipid uptake and secretion of the cytokines monocyte chemotactic protein-1 and regulated upon activation, normal T-cell expressed and secreted, after the uptake of oxidized low-density lipoprotein. CONCLUSIONS These results suggest that the impairment of macrophage function resulting from FcRγ deficiency plays a principal role in the development of LPG in the presence of apoE abnormalities.

Parasites alter the pathological phenotype of lupus nephritis

Abstract Lupus nephritis is one of the most serious complications of systemic lupus erythematosus and manifests with considerable phenotypic and histological heterogeneity. In particular, diffuse proliferative lupus nephritis (DPLN) and membranous lupus nephritis (MLN) represent morphologic forms that are polar opposites. DPLN is associated with autoimmune responses dominated by Th1 immune response associated with high levels of interferon (IFN)-γ. In contrast, a Th2 cytokine response is associated with the pathogenesis of MLN. MRL/lpr mice develop human LN-like immune complex-associated nephritis and provide a suitable histological model for human DPLN. Infection with Schistosoma mansoni skewed a Th2-type immune response induction and IL-10 in MRL/lpr mice, drastically changing the pathophysiology of glomerulonephritis from DPLN to MLN accompanied by increased IgG1 and IgE in the sera. T cells in 32-week-old MRL/lpr mice infected with S. mansoni expressed significantly more IL-4 and IL-10 than T cells of uninfected mice; T cells with IFN-γ were comparable between infected and uninfected MR/lpr mice. Thus, the helminthic infection modified the cytokine microenvironment and altered the pathological phenotype of autoimmune nephritis.

The proportion and metabolic effects of adiponectin multimeric isoforms in patients with chronic kidney disease on maintenance hemodialysis.

Adiponectin circulates at least in three major forms of oligomeric complexes in plasma: a low-molecular-weight (LMW) trimer, a middle-molecular-weight (MMW) hexamer, and high-molecular-weight (HMW) adiponectin. Although it has been reported that adiponectin has the favorable metabolic properties for humans, the roles of these multimers in the patients with the end-stage renal disease (ESRD) were unidentified. We determined the level of total and multimeric adiponectin in 71 patients with nondiabetic ESRD treated with hemodialysis (HD) using a commercially available kit of enzyme-linked immunosorbent assay (ELISA). Correlations between metabolic variables and total and multimeric adiponectin were examined by Spearmans correlations analysis. Forward stepwise multiple linear regression analysis was also performed to determine the factors independently associated with them. Female patients had significantly higher total, HMW, and MMW levels than male patients did. According to homeostasis model of assessment of insulin resistance (HOMA-IR), value was associated not only with HMW but also with MMW and LMW. In multivariate analyses, HMW showed independently and positively associated with high-density lipoprotein cholesterol (HDL-C), body mass index (BMI), and sex as total adiponectin did. Unexpectedly, LMW adiponectin was independently and negatively correlated with TG and high-sensitive C-reactive protein (hs-CRP). Not only HMW adiponectin but also LMW adiponectin track with favorable metabolic effects in the patient with the ESRD.

Improvement of dyslipidemia in OLETF rats by the prostaglandin I2 analog beraprost sodium.

The Otsuka Long-Evans Tokushima Fatty (OLETF) rat was established as an animal model of human type 2 diabetes. Improvement of dyslipidemia by BPS has been confirmed in OLETF rats. The aim of this report is to clarify the mechanisms associated with improvement of dyslipidemia by BPS in OLETF rats. We divided male OLETF rats into three groups; 400microg/kg BPS treated (Group H), 200microg/kg BPS treated (Group L), and untreated control (Group C). After sacrifice, using the quantitative real-time PCR, we assayed the transcription levels of the HMG-CoA reductase (Hmgcr) for cholesterol biosynthesis, monoacylglycerol O-acyltransferase 1 (Mogat1) as TG synthetase, hepatic triglyceride lipase (Lipc) and lipoprotein lipase (Lpl) as triglycerides (TG) reductase in the liver. The mRNA expression of transketolase (Tkt) for pentose phosphate pathway (PPP) enzyme was also evaluated in the liver and kidney. Hmgcr and Mogat1 RNA expression levels were reduced in the livers and those of Tkt were increased in the kidney of BPS treated rats compared with those in untreated rats. The protein expressions of transketolase (Tkt) of BPS treated rats were similarly increased both in the kidney and liver. These results suggest that dyslipidemia was not improved by the acceleration of TG metabolism but by the suppression of activated cholesterol and TG biosyntheses in OLETF rats treated with BPS. High activity of Tkt induced by BPS may be involved in the suppression of such synthetic mechanisms.

Tubulointerstitial nephritis as adverse effect of programmed cell death 1 inhibitor, nivolumab, showed distinct histological findings

Immune-checkpoint inhibitor nivolumab (anti-PD-1 antibody) blocks T cell inhibition and stimulate immunologic response toward cancer cells. It was also revealed that PD-1/PD-L1 interaction crucially controls the effector differentiation of auto-reactive T cells to maintain self-tolerance. Therefore, potential autoimmunological side-effect can occur in any organ. Here, we report a case of 67-year-old Japanese male with lung adenocarcinoma treated with nivolumab who developed acute tubulointerstitial nephritis after the third infusion of nivolumab. Kidney biopsy showed distinct histological findings: Proliferation of CD38 positive and IgG positive plasma cells, and affluent infiltration of FoxP3+ regulatory T cells. Herein, we do pathological discussion concerning acute tubulointerstitial nephritis occurred in this case based on these histological findings.

IL-1β promotes tubulointerstitial injury in MPO-ANCA-associated glomerulonephritis .

BACKGROUND It is widely accepted that tubulointerstitial injury (TII) is caused by glomerular injury (GI) in glomerular diseases. Glomerular endocapillary inflammation may result in crescent formation and exuded protein leakage, which may induce TII in antineutrophil cytoplasmic antibody-associated glomerulonephritis (ANCAGN). However, some reports have indicated a glomerulonephritis-independent mechanism of TII in ANCAGN. The aim of this study was to determine the principle cytokines correlated with TII severity and to elucidate a characteristic mechanism for TII in ANCAGN. METHODS 28 myeloperoxidase-ANCA-positive ANCAGN patients were enrolled, and their kidney biopsy specimens were histologically evaluated with regard to GI and TII. The mRNA expression of various cytokines was examined in 28 specimens. RESULTS Interleukin (IL)-1β was significantly correlated with the severity of TII. The mRNA expression of Toll-like receptor 4 (TLR4) and Nod-like receptor family pyrin domain-containing-3 (NLRP3) also correlated with TII severity. Immunohistochemical analysis demonstrated that TLR4 protein was positively stained in the tubulointerstitial infiltrating cells. NRLP3 protein was detected in macrophages in the severe infiltrating area but was absent or only very faintly expressed in the glomeruli. These results indicated that NLRP3 inflammasome-dependent processing in macrophages releases the mature active form of IL-1β, which may lead to the development and deterioration of TII. CONCLUSIONS Sterile inflammation leads to the formation of ANCA-mediated neutrophil extracellular traps (NETs), which may stimulate macrophages and dendritic cells via TLR4 and induce NF-κB-dependent mRNA expression and translation of pro-IL-1β. Simultaneously, damage-associated molecular pattern signals resulting from NETs promote NLRP3 inflammasome-dependent processing and release mature active IL-1β. Sterile inflammation utilizing the NLRP3 inflammasome might be a characteristic reaction limited to the tubulointerstitium. Thus, neutralizing IL-1β may be a promising strategy to suspend the progress of TII and improve the prognosis of chronic kidney disease resulting from ANCAGN.
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