ABSTRACT
Transforming growth factor (TGF)-ß1 contributes to podocyte injury in various glomerular diseases, including diabetic kidney disease, probably at least in part by attenuating the expression of Wilms' tumor 1 (WT1). However, the precise mechanisms remain to be defined. We performed miRNA microarray analysis in a human podocyte cell line cultured with TGF-ß1 to examine the roles of miRNAs in podocyte damage. The microarray analysis identified miR-143-3p as the miRNA with the greatest increase following exposure to TGF-ß1. Quantitative RT-PCR confirmed a significant increase in the miR-143-3p/145-5p cluster in TGF-ß1-supplemented cultured podocytes and demonstrated upregulation of miR-143-3p in the glomeruli of mice with type 2 diabetes. Ectopic expression of miR-143-3p and miR-145-5p suppressed WT1 expression in cultured podocytes. Furthermore, inhibition of Smad or mammalian target of rapamycin signaling each partially reversed the TGF-ß1-induced increase in miR-143-3p/145-5p and decrease in WT1. In conclusion, TGF-ß1 induces expression of miR-143-3p/145-5p in part through Smad and mammalian target of rapamycin pathways, and miR-143-3p/145-5p reduces expression of WT1 in cultured human podocytes. miR-143-3p/145-5p may contribute to TGF-ß1-induced podocyte injury.NEW & NOTEWORTHY This study by miRNA microarray analysis demonstrated that miR-143-3p expression was upregulated in cultured human podocytes following exposure to transforming growth factor (TGF)-ß1. Furthermore, we report that the miR-143/145 cluster contributes to decreased expression of Wilms' tumor 1, which represents a possible mechanism for podocyte injury induced by TGF-ß1. This study is important because it presents a novel mechanism for TGF-ß-associated glomerular diseases, including diabetic kidney disease (DKD), and suggests potential therapeutic strategies targeting miR-143-3p/145-5p.
Subject(s)
Diabetes Mellitus, Type 2 , Diabetic Nephropathies , MicroRNAs , Podocytes , Transforming Growth Factor beta1 , Animals , Humans , Mice , Diabetes Mellitus, Type 2/metabolism , Diabetic Nephropathies/metabolism , MicroRNAs/metabolism , Podocytes/metabolism , TOR Serine-Threonine Kinases/metabolism , Transforming Growth Factor beta1/metabolism , WT1 Proteins/genetics , WT1 Proteins/metabolismABSTRACT
OBJECTIVES: Otitis media with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (OMAAV) is a new category of otitis media in which cases of otitis media due to ANCA-associated vasculitis (AAV) are classified, regardless of ANCA variant or ANCA serotype. We aimed to describe the clinical features and course of patients with OMAAV and identify factors associated with hearing outcomes. METHODS: We retrospectively analysed 30 patients with OMAAV, classified based on the criteria proposed by the Japan Otological Society in 2016. RESULTS: Single-positive myeloperoxidase-ANCA, single-positive proteinase 3-ANCA, double-positive ANCA, and double-negative ANCA were identified in 47%, 33%, 7%, and 13% of the patients, respectively. All patients subjected to audiometry showed hearing impairments, and 85% were affected bilaterally. Mixed- and sensorineural-type hearing impairments were identified in 80% and 20% of impaired ears, respectively. Hypertrophic pachymeningitis (HPM) was identified in 37% of the patients. Immunosuppressive therapy was administered to 93% of patients, and the median air conduction hearing levels at pre- and post-treatment were 66.1 dB and 43.4 dB, respectively, indicating significant hearing improvements. HPM and a long interval between disease onset and treatment initiation were significantly correlated with poor hearing prognosis. CONCLUSIONS: OMAAV develops under any type of ANCA-serology and typically causes mixed or sensorineural bilateral hearing loss. The early initiation of immunosuppressive therapy and the absence of HPM were associated with good hearing outcomes.
Subject(s)
Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis , Meningitis , Otitis Media , Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis/drug therapy , Antibodies, Antineutrophil Cytoplasmic , Humans , Myeloblastin , Otitis Media/complications , Otitis Media/therapy , Peroxidase , Retrospective StudiesABSTRACT
BACKGROUND: Pregnancy is an important issue for many women with systemic lupus erythematosus (SLE). This study examined maternal and fetal outcomes among SLE women with or without a history of lupus nephritis (LN). METHODS: We retrospectively analyzed 98 pregnancies in 57 women previously diagnosed with SLE who gave birth at our hospital. RESULTS: There were 44 pregnancies in women with a history of LN and 54 pregnancies in those without. Fetal loss was observed in 16.1% of SLE pregnancies when excluding induced abortion, and preeclampsia and SLE flare were observed in 12.2 and 6.1% of SLE pregnancies, respectively. No significant differences were evident between women with or without LN in rate of fetal loss, preeclampsia or SLE flare. Women with a history of LN exhibited a significantly shorter duration of gestation (37.0 weeks vs. 38.4 weeks, P = 0.006) and lower birth weight (2484 g vs. 2746 g, P = 0.007) than those without LN. Multivariate analysis revealed glucocorticoid dose but not history of LN, as an independent risk factor for preterm delivery and low birth weight. CONCLUSION: This study was unable to conclude that a history of LN predicted pregnancy outcomes among SLE women. Instead, a higher dose of glucocorticoid at conception was unexpectedly associated with preterm delivery and low birth weight. Further studies are awaited to verify the relationship.
Subject(s)
Birth Weight , Lupus Nephritis/epidemiology , Pregnancy Complications/epidemiology , Pregnancy Outcome/epidemiology , Adult , Female , Humans , Infant, Low Birth Weight , Infant, Newborn , Japan/epidemiology , Pregnancy , Premature Birth/epidemiology , Retrospective Studies , Risk FactorsABSTRACT
Anti-neutrophil cytoplasmic antibodies-associated vasculitis (AAV) occurs in elderly people, and patients with anti-myeloperoxidase autoantibodies (MPO-ANCA)-positive AAV are often complicated with interstitial lung disease (ILD). This study aimed to evaluate the age-related clinical features of elderly patients with MPO-ANCA-positive AAV-ILD. This study retrospectively investigated 63 patients with MPO-ANCA-positive AAV-ILD, all of whom were 65 years or older at diagnosis. Clinical characteristics, causes of death and survival rates among three groups stratified by age (65-74 years, n = 29; 75-79 years, n = 18; over 80 years, n = 16) were compared. This study also examined the association with severe infections in these patients. Among the three age groups, there were significant differences in sex (P = 0.032), serum Krebs von den Lungen-6 (P < 0.01), and total ground-glass opacity score (P = 0.011). The causes of death were mainly severe infections and complications of ILD. Kaplan-Meier curve analysis showed a significantly lower 5-year survival rate in the oldest group (P < 0.01). Regarding severe infections in these patients, the 5-year cumulative incidence of severe infections was higher in the patients receiving steroid pulse therapy (P = 0.034). The clinical characteristics of MPO-ANCA-positive AAV-ILD differ with age in elderly patients, with age being an important poor prognostic factor in these patients. The administration of steroid pulse therapy is a significant risk factor of severe infection in MPO-ANCA-positive elderly patients with AAV-ILD.
Subject(s)
Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis/immunology , Lung Diseases, Interstitial/immunology , Aged , Aged, 80 and over , Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis/mortality , Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis/physiopathology , Autoantibodies/blood , Female , Humans , Kaplan-Meier Estimate , Lung Diseases, Interstitial/mortality , Lung Diseases, Interstitial/physiopathology , Male , Retrospective StudiesABSTRACT
OBJECTIVES: Anti-melanoma differentiation-associated gene 5 (MDA5) autoantibody-positive and age at onset ≥60 years are poor prognosis factors in polymyositis (PM) and dermatomyositis (DM) associated with interstitial lung disease (ILD) among Japanese patients. However, the influence of age on the clinical features of anti-MDA5 autoantibody-positive patients with DM remains unclear. METHODS: We retrospectively examined 40 patients with DM and anti-MDA5 autoantibodies according to age. We compared patients aged <60 and ≥60 years with respect to clinical features including laboratory test findings, high-resolution lung computed tomography data, treatment content, and complications such as infections and prognosis. We also examined clinical features between surviving and deceased patients in the older patient group. RESULTS: Of 40 enrolled patients, 13 were classified as old and 27 as young. Older patients had significantly fewer clinical symptoms including arthralgia/arthritis (p < .01), skin ulceration (p = .02), and higher mortality than younger patients (p = .02) complicated with rapidly progressive ILD (RP-ILD), combination immunosuppressive therapy, and strictly controlled infections. CONCLUSION: Clinical features and mortality of anti-MDA5 autoantibody-positive DM patients were influenced by age. Patients aged ≥60 years had a worse prognosis, and combination immunosuppressive therapy was often ineffective for RP-ILD in older patients.
Subject(s)
Autoantibodies/immunology , Dermatomyositis/pathology , Interferon-Induced Helicase, IFIH1/immunology , Adult , Age Factors , Aged , Dermatomyositis/drug therapy , Dermatomyositis/epidemiology , Dermatomyositis/immunology , Female , Humans , Immunosuppressive Agents/therapeutic use , Male , Middle Aged , MortalityABSTRACT
AIM: Wilms' tumour 1 (WT1) is essential for normal podocyte function. Previous reports have demonstrated that the WT1 promoter is often methylated in cancers, leading to transcriptional silencing. Transforming growth factor-ß1 (TGF-ß1) is reported to down-regulate WT1 expression in podocytes. Based on the hypothesis that epigenetic modification plays a role in this process, we examined whether TGF-ß1 affects the methylation status of WT1 regulatory regions. METHODS: Conditional immortalized human podocytes were treated with TGF-ß1. A human renal proximal tubular epithelial cell line (HK2), which does not express WT1, was used as a control. The degree of DNA methylation of the WT1 promoter, 5' enhancer, intron 3 enhancer and 3' enhancer was determined using quantitative methylation-specific PCR, bisulfite sequencing and pyrosequencing. RESULTS: Both WT1 mRNA and protein expression were reduced by long-term treatment with TGF-ß1. The WT1 promoter was hypomethylated, and the 5' enhancer and intron 3 enhancer were substantially methylated in untreated podocytes. In contrast, in HK2 cells, the WT1 promoter was strongly methylated, and the 5' enhancer and intron 3 enhancer were less methylated than in untreated podocytes. TGF-ß1 tended to increase WT1 promoter methylation, tended to decrease 5' enhancer methylation and significantly decreased intron 3 enhancer methylation in podocytes. Methylation levels of the 3' enhancer did not differ among untreated cells, TGF-ß1-treated podocytes or HK2 cells. CONCLUSION: Our data suggest that the methylation pattern of the WT1 promoter and enhancers in human podocytes are distinctive from those in HK2. Furthermore, TGF-ß1 alters the methylation levels of the WT1 promoter and enhancers in human podocytes. This modification may be relevant to the attenuation of WT1 by TGF-ß1, which could contribute to podocyte injury.
Subject(s)
DNA Methylation/drug effects , Enhancer Elements, Genetic/drug effects , Epigenesis, Genetic/drug effects , Podocytes/drug effects , Promoter Regions, Genetic/genetics , Transforming Growth Factor beta1/pharmacology , WT1 Proteins/genetics , Cell Line , Humans , Kidney Tubules, Proximal/drug effects , Kidney Tubules, Proximal/metabolism , Podocytes/metabolism , WT1 Proteins/metabolismABSTRACT
Lupus nephritis is a life-threatening complication of systemic lupus erythematosus (SLE). Various growth factors, cytokines, and chemokines are implicated in the development of SLE. However, the pathophysiological processes involved in the development of lupus nephritis still remain unclear. In this study, we examined the involvement of activin A, a member of the transforming growth factor ß (TGF-ß) superfamily, in the progression of renal damage in lupus-prone MRL-lpr mice. Activin A was not expressed in the kidneys of control MRL-MpJ mice but was detectable in perivascular infiltrating cluster of differentiation 68 (CD68)-positive cells in the kidneys of MRL-lpr mice. Urinary activin A, which was also absent in MRL-MpJ mice, was detectable in MRL-lpr mice from 16 wk onward. Urinary activin A levels were significantly correlated with the number of perivascular inflammatory cell layers, the number of crescentic glomeruli, and the percentage of Elastica van Gieson (EVG)-positive fibrotic areas, but not with urinary protein levels or serum activin A. When activin action was blocked in vivo by the intraperitoneal administration of an activin antagonist, follistatin, the number of crescentic glomeruli, percentage of EVG-positive fibrotic areas, CD68-positive cell infiltration, and proteinuria were significantly reduced in a dose-dependent manner. These data suggest that infiltrating macrophage-derived activin A is involved in the progression of renal damage in MRL-lpr mice.
Subject(s)
Activins/metabolism , Kidney/metabolism , Lupus Nephritis/metabolism , Macrophages/metabolism , Animals , Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , Biomarkers/urine , Disease Progression , Female , Fibrosis/metabolism , Fibrosis/pathology , Follistatin/pharmacology , Kidney/drug effects , Kidney/pathology , Lupus Nephritis/pathology , Macrophages/drug effects , Macrophages/pathology , Mice , Mice, Inbred MRL lpr , Proteinuria/metabolism , Proteinuria/pathologyABSTRACT
BACKGROUND: Aberrant expression of T helper cell (Th) cytokines is believed to play a central role in the pathogenesis of systemic lupus erythematosus (SLE). While the glomerulus is one of the major targets of lupus inflammation, little is known about the cytokine expression in glomeruli. The current study aimed to explore the profiles of Th cytokine gene expressions in isolated glomeruli of lupus-prone mice. METHODS: Glomeruli were purified from lupus-prone MRL/lpr mice using the magnetic microbead method. Expressions of cytokine genes representing the Th subset and FoxP3 were examined using real-time polymerase chain reaction. Serum levels of these cytokines were also measured by enzyme-linked immunosorbent assay. MRL/n mice were used as controls. Histologic glomerular damages were scored semiquantitatively. To examine the role of TNF-α in glomerular damage, we administered etanercept, a TNF-α antagonist, into the subjects. RESULTS: Glomerular gene expressions of TNF-α in lpr mice increased with week postpartum and reached statistically significant levels at 16 weeks compared with those of the glomeruli from control mice. Expressions of IFN-γ, IL-4 and FoxP3 also increased, but the difference was not significant. There was a significant increase in serum levels of TNF-α, IFN-γ, and IL-17 and decrease in those of IL-4. Among the genes examined, TNF-α significantly correlated with glomerular damage score. Administration of etanercept did not affect glomerular cytokine expressions or proteinuria and failed to ameliorate histologic glomerular damages. CONCLUSION: Our data suggest that Th1 cytokines, especially TNF-α, are dominantly expressed in the glomeruli of lupus-prone mice, but its pathophysiological role remains unclear.
Subject(s)
Cytokines/metabolism , Kidney Glomerulus/metabolism , Lupus Nephritis/metabolism , T-Lymphocytes, Helper-Inducer/metabolism , Animals , Biological Products/pharmacology , Cytokines/antagonists & inhibitors , Cytokines/genetics , Cytokines/immunology , Disease Models, Animal , Etanercept/pharmacology , Female , Forkhead Transcription Factors/genetics , Forkhead Transcription Factors/metabolism , Gene Expression Regulation , Kidney Glomerulus/drug effects , Kidney Glomerulus/immunology , Kidney Glomerulus/pathology , Lupus Nephritis/genetics , Lupus Nephritis/immunology , Lupus Nephritis/pathology , Mice, Inbred MRL lpr , T-Lymphocytes, Helper-Inducer/drug effects , T-Lymphocytes, Helper-Inducer/immunology , Time FactorsABSTRACT
A 62-year-old male patient presented with progressive renal dysfunction for 2 months. He had elevated serum C-reactive protein and IgG4 levels with absence of anti-neutrophil cytoplasmic antibodies. A renal biopsy showed severe tubulointerstitial nephritis (TIN) with extensive infiltration of IgG4-positive plasma cells, suggesting a diagnosis of IgG4-related kidney disease (IgG4-RKD). However, the identification of a few crescentic glomeruli and necrotizing vasculitis of an interlobular artery lead to a diagnosis of renal small-vessel vasculitis. This case indicates that a careful examination is required to distinguish between IgG4-RKD and TIN caused by renal small-vessel vasculitis.
Subject(s)
Immunoglobulin G/immunology , Kidney/pathology , Plasma Cells/pathology , Vasculitis/pathology , Antibodies, Antineutrophil Cytoplasmic , Humans , Kidney/immunology , Male , Middle Aged , Plasma Cells/immunology , Vasculitis/immunologyABSTRACT
OBJECTIVES: In this study, we aimed to assess the effect of combination of proliferative and membranous lesions (Class III + V or IV + V) on renal outcomes as an independent category distinct from Class III and IV. METHODS: We retrospectively analyzed 103 Japanese patients (14 male and 89 female) with Class III/IV LN, with or without Class V, who underwent renal biopsy and were treated at our institution. Renal endpoint was defined as doubling of serum creatinine or end-stage renal disease (ESRD). RESULTS: The number of patients in each group was as follows: pure Class III/IV, 81 patients and mixed Class III/IV + V, 22 patients. During a median follow-up period of 125.0 months, 10 patients developed renal endpoint: five had Class III/IV LN and five had a combination of Class III/IV + V. Kaplan-Meier analyses demonstrated that patients with mixed Class III/IV + V LN had significantly poorer renal outcomes than patients with Class III/IV LN. Multivariate Cox regression analyses identified serum creatinine, active and chronic lesions (A/C), and mixed Class III/IV + V) as independent risk factors for poor renal outcomes. CONCLUSIONS: This study demonstrated a combination of proliferative and membranous LN (ISN/RPS Class III/IV + V) predicts poor renal outcomes.
Subject(s)
Kidney/pathology , Lupus Nephritis/pathology , Adult , Female , Humans , Male , Middle AgedABSTRACT
Sestrin 2, initially identified as a p53 target protein, accumulates in cells exposed to stress and inhibits mammalian target of rapamycin (mTOR) signaling. In normal rat kidneys, sestrin 2 was selectively expressed in parietal epithelial cells (PECs), identified by the marker protein gene product 9.5. In adriamycin nephropathy, sestrin 2 expression decreased in PECs on day 14, together with increased expression of phosphorylated S6 ribosomal protein (P-S6RP), a downstream target of mTOR. Sestrin 2 expression was markedly decreased on day 42, coinciding with glomerulosclerosis and severe periglomerular fibrosis. In puromycin aminonucleoside nephropathy, decreased sestrin 2 expression, increased P-S6RP expression, and periglomerular fibrosis were observed on day 9, when massive proteinuria developed. These changes were transient and nearly normalized by day 28. In crescentic glomerulonephritis, sestrin 2 expression was not detected in cellular crescents, whereas P-S6RP increased. In conditionally immortalized cultured PECs, the forced downregulation of sestrin 2 by short hairpin RNA resulted in increased expression of P-S6RP and increased apoptosis. These data suggest that sestrin 2 is involved in PEC homeostasis by regulating the activity of mTOR. In addition, sestrin 2 could be a novel marker of PECs, and decreased expression of sestrin 2 might be a marker of PEC injury.
Subject(s)
Kidney Diseases/metabolism , Kidney Glomerulus/metabolism , Nuclear Proteins/metabolism , TOR Serine-Threonine Kinases/metabolism , Animals , Cells, Cultured , Down-Regulation , Doxorubicin , Epithelial Cells/metabolism , Hyaluronan Receptors/metabolism , Kidney Diseases/chemically induced , Male , Mice , Puromycin Aminonucleoside , RNA, Small Interfering , Rats , Rats, Inbred WKY , Rats, Wistar , Ribosomal Protein S6/metabolismABSTRACT
Lecithin-cholesterol acyltransferase (LCAT) is an enzyme involved in maintaining cholesterol homeostasis. In familial LCAT deficiency (FLD), abnormal lipid deposition causes renal injury and nephrotic syndrome, frequently progressing to ESRD. Here, we describe a 63-year-old Japanese woman with no family history of renal disease who presented with nephrotic syndrome. The laboratory data revealed an extremely low level of serum HDL and undetectable serum LCAT activity. Renal biopsy showed glomerular lipid deposition with prominent accumulation of foam cells, similar to the histologic findings of FLD. In addition, she had subepithelial electron-dense deposits compatible with membranous nephropathy, which are not typical of FLD. A mixing test and coimmunoprecipitation study demonstrated the presence of an inhibitory anti-LCAT antibody in the patient's serum. Immunohistochemistry and immunofluorescence detected LCAT along parts of the glomerular capillary walls, suggesting that LCAT was an antigen responsible for the membranous nephropathy. Treatment with steroids resulted in complete remission of the nephrotic syndrome, normalization of serum LCAT activity and HDL level, and disappearance of foam cell accumulation in renal tissue. In summary, inhibitory anti-LCAT antibody can lead to glomerular lesions similar to those observed in FLD.
Subject(s)
Glomerulonephritis, Membranous/etiology , Kidney/pathology , Lecithin Cholesterol Acyltransferase Deficiency/diagnosis , Nephrotic Syndrome/etiology , Female , Fluorescent Antibody Technique , Glomerulonephritis, Membranous/pathology , Humans , Immunohistochemistry , Lecithin Cholesterol Acyltransferase Deficiency/complications , Lecithin Cholesterol Acyltransferase Deficiency/pathology , Middle Aged , Nephrotic Syndrome/pathologyABSTRACT
OBJECTIVES: To examine the efficacy and safety of multi-target therapy using tacrolimus (TAC), mycophenolate mofetil (MMF) and a steroid as initial treatment for active lupus nephritis (LN). METHODS: We conducted a retrospective analysis of the data of 16 consecutive patients who received the multi-target therapy for active Classes III-V LN at our department. We also compared the outcomes of the multi-target therapy with those of TAC therapy (TAC + steroid), a study of which we had conducted previously in 13 patients with active LN (TAC group). RESULTS: All the patients treated with multi-target therapy achieved complete remission (CR) (mean, 4.6 ± 3.8 months; range, 1-15 months). The clinical profiles of the patients of the multi-target group were similar to those of the TAC group at baseline, except for a significantly higher level of proteinuria (4.6 ± 2.8 vs. 2.5 ± 2.1 g/gCr, p = 0.033) in the former. The CR rate at 6 months was significantly higher in the multi-target group as compared with that in the TAC group (81% vs. 38%, p = 0.018). Two cases of serious adverse events were associated with cytomegalovirus infection in the multi-target group, namely gastric ulcer and pancytopenia, both of which were successfully treated by antiviral therapy. CONCLUSIONS: Multi-target therapy was effective as initial treatment for active LN, with CR achieved early and in a high percentage of patients. Although this therapy was generally well tolerated, it is important to bear in mind the associated risk of cytomegalovirus infection.
Subject(s)
Immunosuppressive Agents/therapeutic use , Lupus Nephritis/drug therapy , Mycophenolic Acid/analogs & derivatives , Prednisolone/therapeutic use , Tacrolimus/therapeutic use , Adult , Drug Therapy, Combination , Female , Humans , Immunosuppressive Agents/adverse effects , Male , Middle Aged , Mycophenolic Acid/adverse effects , Mycophenolic Acid/therapeutic use , Prednisolone/adverse effects , Remission Induction , Retrospective Studies , Tacrolimus/adverse effects , Treatment Outcome , Young AdultABSTRACT
Transforming growth factor (TGF)-ß has been associated with podocyte injury; we have examined its effect on podocyte bioenergetics. We studied transformed mouse podocytes, exposed to TGF-ß1, using a label-free assay system, Seahorse XF24, which measures oxygen consumption rates (OCR) and extracellular acidification rates (ECAR). Both basal OCR and ATP generation-coupled OCR were significantly higher in podocytes exposed to 0.3-10 ng/ml of TGF-ß1 for 24, 48, and 72 h. TGF-ß1 (3 ng/ml) increased oxidative capacity 75%, and 96% relative to control after 48 and 72 h, respectively. ATP content was increased 19% and 30% relative to control after a 48- and 72-h exposure, respectively. Under conditions of maximal mitochondrial function, TGF-ß1 increased palmitate-driven OCR by 49%. Thus, TGF-ß1 increases mitochondrial oxygen consumption and ATP generation in the presence of diverse energy substrates. TGF-ß1 did not increase cell number or mitochondrial DNA copy number but did increase mitochondrial membrane potential (MMP), which could explain the OCR increase. Reactive oxygen species (ROS) increased by 32% after TGF-ß1 exposure for 48 h. TGF-ß activated the mammalian target of rapamycin (mTOR) pathway, and rapamycin reduced the TGF-ß1-stimulated increases in OCR, ECAR, ATP generation, cellular metabolic activity, and protein generation. Our data suggest that TGF-ß1, acting, in part, via mTOR, increases mitochondrial MMP and OCR, resulting in increased ROS generation and that this may contribute to podocyte injury.
Subject(s)
Mitochondria/drug effects , Oxidative Phosphorylation/drug effects , Podocytes/drug effects , Reactive Oxygen Species/metabolism , TOR Serine-Threonine Kinases/metabolism , Transforming Growth Factor beta1/pharmacology , Adenosine Triphosphate/metabolism , Animals , Antigens, Polyomavirus Transforming/genetics , Antigens, Polyomavirus Transforming/metabolism , Apoptosis/drug effects , Biosensing Techniques , Cells, Cultured , Dose-Response Relationship, Drug , Fatty Acids/metabolism , Glycolysis/drug effects , Humans , Hydrogen-Ion Concentration , Intracellular Signaling Peptides and Proteins/genetics , Intracellular Signaling Peptides and Proteins/metabolism , Membrane Potential, Mitochondrial/drug effects , Membrane Proteins/genetics , Membrane Proteins/metabolism , Mice , Mice, Transgenic , Mitochondria/enzymology , Mitochondria/pathology , Podocytes/enzymology , Podocytes/pathology , Protein Kinase Inhibitors/pharmacology , Recombinant Proteins/pharmacology , Signal Transduction/drug effects , TOR Serine-Threonine Kinases/antagonists & inhibitors , Time FactorsABSTRACT
Signal-regulatory protein-α (SIRPα) is a transmembrane protein that contains tyrosine phosphorylation sites in its cytoplasmic region; two tyrosine phosphatases, SHP-1 and SHP-2, bind to these sites in a phosphorylation-dependent manner and transduce multiple intracellular signals. Recently, SIRPα was identified as one of the major tyrosine-phosphorylated proteins in the glomeruli and found to be expressed in podocytes. In the present study, we examined the role of SIRPα expression in podocytes using knockin mice (C57BL/6 background) expressing mutant SIRPα that lacks a cytoplasmic region (SIRPα-mutant mice). Light microscopic examination revealed no apparent morphological abnormalities in the kidneys of the SIRPα-mutant mice. On the other hand, electron microscopic examination revealed abnormal podocytes with irregular major processes and wider and flattened foot processes in the SIRPα-mutant mice compared with their wild-type counterparts. Significantly impaired renal functions and slight albuminuria were demonstrated in the SIRPα-mutant mice. In addition, adriamycin injection induced massive albuminuria together with focal glomerulosclerosis in the SIRPα-mutant mice, while their wild-type counterparts were resistant to adriamycin-induced nephropathy. These data demonstrate that SIRPα is involved in the regulation of podocyte structure and function as a filtration barrier under both physiological and pathological conditions.
Subject(s)
Podocytes/physiology , Receptors, Immunologic/physiology , Albuminuria/etiology , Animals , Doxorubicin/toxicity , Glomerulonephritis/chemically induced , Male , Mice , Mice, Inbred C57BL , Microscopy, Electron , Receptors, Immunologic/biosynthesis , Receptors, Immunologic/genetics , Signal Transduction/physiology , src Homology DomainsABSTRACT
INTRODUCTION: Patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis and idiopathic interstitial lung diseases (IIPs) are positive for myeloperoxidase (MPO)-ANCA. MPO-ANCA-positive vasculitis mainly comprises microscopic polyangiitis (MPA) and unclassifiable vasculitis. These diseases are frequently complicated by interstitial lung disease (ILD). Few studies have reported the clinical differences between the subtypes of MPO-ANCA-positive ILD. Therefore, this study aimed to examine the clinical findings and courses of MPO-ANCA-positive ILD. METHOD: This retrospective study enrolled 100 patients with MPO-ANCA-positive ILD who were categorized into three groups: MPA (n = 44), unclassifiable vasculitis (n = 29), and IIP (n = 27). Our study compared the clinical findings and prognosis of these patients and analyzed the poor prognostic factors. Furthermore, we assessed the association between the patients with and without acute exacerbation of ILD (AE-ILD). RESULTS: Our study found clinical differences in serum markers, clinical symptoms, and treatment regimens among the three groups. ILD complications, as the main cause of death, differed among the three groups (P = 0.04). Patients with unclassifiable vasculitis showed higher survival rates than those with IIP (P = 0.046). Patients with AE-ILD showed fewer general symptoms (P = 0.02) and lower survival rates (P < 0.01) than those without AE-ILD. In multivariate analysis, AE-ILD development was a strong poor prognostic factor for MPO-ANCA-positive ILD. CONCLUSIONS: The subtypes of MPO-ANCA-positive ILD have different clinical features and prognoses. Patients who develop AE-ILD require careful evaluation of clinical courses. Key Points ⢠In myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA)-positive interstitial lung disease (ILD), patients with unclassifiable vasculitis showed a better prognosis than those with idiopathic ILD.. ⢠Development of acute exacerbation in ILD was a strong poor prognostic factor in patients with MPO-ANCA-positive ILD..
Subject(s)
Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis , Lung Diseases, Interstitial , Microscopic Polyangiitis , Humans , Antibodies, Antineutrophil Cytoplasmic , Retrospective Studies , Peroxidase , Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis/complications , Microscopic Polyangiitis/complicationsABSTRACT
OBJECTIVE: To examine whether IL-6 promotes angiogenesis by modulating angiopoietin (Ang) expression in RA. METHODS: Synovial fibroblasts derived from RA patients (RASFs) and human umbilical vein endothelial cells (HUVECs) were co-cultured for 6 days with or without recombinant IL-6, VEGF or Ang-1. HUVECs were stained with anti-CD31 antibody and their growth was determined by quantifying the CD31-positive area. SFs were collected from RA (n = 25) and OA (n = 7) patients. RESULTS: In the co-culture system, IL-6 and VEGF significantly enhanced HUVEC growth to a similar extent. However, the morphology of proliferating cells was distinct between IL-6- and VEGF-stimulated HUVEC. HUVEC stimulated with IL-6 exhibited small, loose clusters surrounded by dispersed single cells, suggesting destabilized angiogenesis by IL-6. In the supernatants, IL-6 up-regulated VEGF compared with controls and Ang-2, while it down-regulated Ang-1. In contrast, down-regulation of Ang-1 was not observed with VEGF stimulation. Consistent with the destabilized morphology, stimulation with IL-6 decreased cell surface expression of vascular endothelial cadherin (VE-cadherin) on HUVEC, presumably by inducing internalization. Interestingly, adding recombinant Ang-1 partially inhibited IL-6-induced morphological changes in HUVEC including a destabilized morphology with small, loose clusters and internalization of VE-cadherin. In SFs from RA patients, VEGF was negatively correlated with Ang-1 (r = -0.559, P=0.004). CONCLUSION: IL-6 not only enhances VEGF expression but also inhibits Ang-1 signalling by directly down-regulating Ang-1 expression and up-regulating Ang-2, an antagonist of Ang-1. These synergistic effects may play a critical role in destabilized angiogenesis in RA.
Subject(s)
Angiopoietin-1/metabolism , Arthritis, Rheumatoid/immunology , Interleukin-6/pharmacology , Neovascularization, Pathologic/drug therapy , Angiopoietin-1/pharmacology , Arthritis, Rheumatoid/pathology , Biomarkers/metabolism , Cell Proliferation/drug effects , Coculture Techniques , Fibroblasts/drug effects , Fibroblasts/metabolism , Fibroblasts/pathology , Human Umbilical Vein Endothelial Cells/drug effects , Human Umbilical Vein Endothelial Cells/physiology , Humans , Neovascularization, Pathologic/pathology , Recombinant Proteins , Synovial Membrane/drug effects , Synovial Membrane/metabolism , Synovial Membrane/pathology , Vascular Endothelial Growth Factor A/pharmacologyABSTRACT
OBJECTIVE: In RA, response to TNF blockers may be associated with a profile of cytokine production unique to each patient. This study sought to predict the response to biologic agents by examining pro-inflammatory cytokine synthesis in stimulated whole blood cultures (WBCs). METHODS: We measured the concentration of TNF-α, IL-1ß and IL-6 in supernatants of lipopolysaccharide (LPS)-stimulated WBCs obtained from RA patients (n = 41) before anti-TNF therapy (infliximab, 13; etanercept, 26; and adalimumab, 2) and from healthy controls (n = 12). At 24 weeks after biologics, whole bloods were again drawn from 14 of 41 patients. Response was defined by the European League Against Rheumatism response criteria after 24 weeks of therapy. RESULTS: Among 41 patients, 32 were responders (good 14/moderate 18), while 9 were non-responders. All cytokines measured were significantly lower in RA patients than in controls. In RA, IL-1ß production was lower in non-responders than in responders [median (interquartile range): 3.5 (1.5-9.4) vs 10.0 (5.1-93.1) pg/ml, P = 0.048]. The area under the curve from a receiver operating characteristic curve analysis for the prediction of response using IL-1ß was 0.717 (95% CI 0.520, 0.914). The sensitivity and specificity of IL-1ß (cut-off value 4.84 pg/ml) was 78.1 and 77.8%, respectively. All cytokines were significantly higher 6 months later compared with their respective baseline. CONCLUSION: IL-1ß measurement in LPS-stimulated WBC is useful to predict responsiveness to anti-TNF agents. Cytokine production capacities in LPS-stimulated WBCs are up-regulated by biologics.
Subject(s)
Antibodies, Monoclonal/pharmacology , Antirheumatic Agents/pharmacology , Arthritis, Rheumatoid/blood , Blood Cells/drug effects , Interleukin-1beta/metabolism , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Adalimumab , Adult , Antibodies, Monoclonal, Humanized/pharmacology , Arthritis, Rheumatoid/diagnosis , Arthritis, Rheumatoid/drug therapy , Blood Cells/metabolism , Cells, Cultured/drug effects , Cells, Cultured/metabolism , Etanercept , Female , Humans , Immunoglobulin G/pharmacology , Infliximab , Interleukin-1beta/analysis , Lipopolysaccharides/pharmacology , Male , Predictive Value of Tests , ROC Curve , Receptors, Tumor Necrosis Factor/therapeutic use , Treatment OutcomeABSTRACT
We describe a case of relapsed granulomatosis with polyangiitis (Wegener's) (GPA) that presented with abdominal pain. (18)F-fluoro-2-deoxy-D: -glucose positron emission tomography (FDG-PET)/computed tomography (CT) clearly depicted an inflammation of the left peri-iliac arterial soft tissue, which was thought to be the cause of the ureteral obstruction and hydronephrosis. Our case shows that peri-iliac arterial inflammation occurs in GPA and causes hydronephrosis. In addition, FDG-PET/CT is a useful tool for management of this systemic inflammatory disease.
Subject(s)
Granulomatosis with Polyangiitis/diagnosis , Hydronephrosis/diagnosis , Microscopic Polyangiitis/diagnosis , Aged , Cyclophosphamide/therapeutic use , Drug Therapy, Combination , Fluorodeoxyglucose F18 , Glucocorticoids/therapeutic use , Granulomatosis with Polyangiitis/complications , Granulomatosis with Polyangiitis/drug therapy , Humans , Hydronephrosis/etiology , Hydronephrosis/surgery , Immunosuppressive Agents/therapeutic use , Male , Methylprednisolone/therapeutic use , Microscopic Polyangiitis/complications , Microscopic Polyangiitis/drug therapy , Multimodal Imaging , Positron-Emission Tomography , Recurrence , Remission Induction , Tomography, Emission-Computed , Tomography, X-Ray ComputedABSTRACT
A 41-year-old woman with a 14-month history of systemic lupus erythematosus (SLE) presented with headache, aphasia, and agraphia. A laboratory examination revealed mild proteinuria, hypocomplementemia, and elevated anti-double-stranded DNA antibody levels. A cerebrospinal fluid analysis demonstrated elevated protein and interleukin-6 levels. Magnetic resonance imaging (MRI) of the brain identified multiple lesions suggestive of brain edemas and small haemorrhages. She was diagnosed as having neuropsychiatric lupus and lupus nephritis and received remission induction therapy with high-dose corticosteroid and intravenous cyclophosphamide. She achieved a complete remission, and treatment with mycophenolate mofetil (MMF) was initiated 3 months thereafter for remission maintenance. At 13 months after the exacerbation of SLE, she complained of headache and nausea. A gadolinium-enhanced MRI of the brain revealed a low-signal-intensity tumour with marginal ring enhancement of 50 mm in the left frontal lobe. The tumour was excised, and the histological diagnosis was diffuse large B-cell lymphoma with positive Epstein-Barr virus (EBV). MMF was discontinued. Remission induction therapy with rituximab, high-dose methotrexate, procarbazine, and vincristine was administered, and she achieved remission. Previous reports suggest that use of MMF is associated with primary central nervous system (CNS) lymphoma (PCNSL) in patients with lupus nephritis or other autoimmune diseases or in post-transplant patients. Our observation that PCNSL occurred after CNS involvement of SLE suggests that EBV and CNS inflammation arising from SLE might have contributed to the development of PCNSL.