Qiu Li

The prevalence of Th17 cells and FOXP3 regulate T cells (Treg) in children with primary nephrotic syndrome

The aim of this study was to investigate the prevalence of interleukin (IL)-17-producing CD4+ T cells (Th17) and regulatory T (Treg) cells in children with primary nephrotic syndrome. The study cohort consisted of 62 children who were randomly divided into control, primary nephrotic syndrome, and isolated hematuria groups. Flow cytometric analysis revealed the presence of Th17 cells in the peripheral blood mononuclear cells (PBMCs) of 35 children and Tregs in the PBMCs of all children. In addition, mRNA expression of Th17-related factors [IL-17, -23p19 and retinoid orphan nuclear receptor (RORc)] and the concentration of plasma inflammatory mediators such as IL-6 and IL-1β were consistently detected in all children. Protein expression of IL-17 and transforming growth factor-β1 were also detected in renal biopsy tissue and compared between different groups. Patients with PNS were found to have an increased number of Th17 cells and decreased numbers of Tregs in their PBMCs, and there was significant difference in the prevalence of Th17 and Tregs between the patients with PNS and those with isolated hematuria. Our data show that among our study cohort, there was a dynamic equilibrium between Th17 and Treg cells in children with PNS following the development of PNS with apparent renal tubular epithelial cell and interstitium lesions. The dynamic interaction between Th17 and Treg cells may be important in the development of PNS.

Inflammatory stress exacerbates lipid-mediated renal injury in ApoE/CD36/SRA triple knockout mice.

Both lipids and inflammation play important roles in the progression of kidney disease. This study was designed to investigate whether inflammation exacerbates lipid accumulation via LDL receptors (LDLr), thereby causing renal injury in C57BL/6J mice, apolipoprotein E (ApoE) knockout (KO) mice, and ApoE/CD36/scavenger receptor A triple KO mice. The mice were given a subcutaneous casein injection to induce inflammatory stress. After 14 wk, terminal blood samples were taken for renal function, lipid profiles, amyloid A (SAA), and IL-6 assays. Lipid accumulation in kidneys was visualized by oil red O staining. Fibrogenic molecule expression in kidneys was examined. There was a significant increase in serum SAA and IL-6 in the all casein-injected mice compared with respective controls. Casein injection reduced serum total cholesterol, LDL cholesterol, and HDL cholesterol and caused lipid accumulation in kidneys from three types of mice. The expression of LDLr and its regulatory proteins sterol-responsive element-binding protein (SREBP) 2 and SREBP cleavage-activating protein (SCAP) were upregulated in inflamed mice compared with controls. Casein injection induced renal fibrosis accompanied by increased expression of fibrogenic molecules in the triple KO mice. These data imply that inflammation exacerbates lipid accumulation in the kidney by diverting lipid from the plasma to the kidney via the SCAP-SREBP2-LDLr pathway and causing renal injury. Low blood cholesterol levels, resulting from inflammation, may be associated with high risk for chronic renal fibrosis.

Regulatory T cell microRNA expression changes in children with acute Kawasaki disease

Kawasaki disease (KD) is a type of systemic vasculitis syndrome related to immune dysfunction. Previous studies have implicated that dysfunctional regulatory T cells (Treg) may be associated with the immune dysfunction in KD. In the absence of microRNAs (miRNAs), forkhead box protein 3 (FoxP3)+ Treg develop but fail to maintain immune homeostasis. This study was designed to investigate the effects of miR‐155, miR‐21 and miR‐31 on Treg in children with KD. The proportions of CD4+CD25+FoxP3+ Treg and the mean fluorescence intensity (MFI) of phosphorylated‐signal transducer and activator of transcription (pSTAT)‐5 and pSTAT‐3 protein in CD4+CD25+ Treg were analysed by flow cytometry. The concentration of interleukin (IL)‐6 in plasma was measured by cytometric bead array. Real‐time polymerase chain reaction was performed to detect the levels of microRNAs and associated factors in CD4+CD25+ Treg. The proportion of Treg and the mRNA levels of the associated factors [FoxP3, glucocorticoid‐induced tumour necrosis factor‐receptor (GITR), cytotoxic T lymphocyte antigen (CTLA)‐4)] were significantly lower in KD patients (P < 0·05). MiR‐155 and miR‐21 levels were significantly down‐regulated and miR‐31 expression was higher in KD patients (P < 0·05). Plasma interleukin (IL)‐6 concentrations, pSTAT‐3 protein levels and suppressors of cytokine signalling (SOCS)‐1 mRNA expression were remarkably elevated in acute KD (P < 0·05), while pSTAT‐5 protein levels were remarkably decreased in acute KD (P < 0·05). These findings were reversed after intravenous immunoglobulin treatment (P < 0·05). Our results demonstrate that FoxP3 mRNA levels were primarily affected by the miR‐155/SOCS1 and the miR‐31 signalling pathways. These results suggest that the decrease in FoxP3+ Treg might be associated with decreased expression of miR‐155, leading to aberrant SOCS1/STAT‐5 signalling and overexpression of miR‐31 in patients with acute KD.

The Role of Th17/IL-17 in the Pathogenesis of Primary Nephrotic Syndrome in Children

Background: This work aims to explore the role of Th17 and IL-17 signaling in the pathogenesis of primary nephrotic syndrome (PNS) in children and podocyte injury, children with PNS were divided into minimal change nephrotic syndrome (MCNS) and non-minimal change nephrotic syndrome [NMCNS, including mesangial proliferative glomerulonephritis (MsPGN) and focal segmental glomerulosclerosis (FSGS)]. Methods: Flow cytometry (FCM) was used to observe the circulating frequency of Th17 cells and the apoptosis of podocytes by annexinV-FITC/PI. Serum IL-1β and IL-6 levels were measured using enzyme-linked immunosorbent assay. The Fas and FasL expressions in podocytes were examined by FCM analysis using a direct immunofluorescence method. Reverse transcription polymerase chain reaction was applied to measure the mRNA expressions of RORc, IL-23p19, Nephrin, WT1, Synaptopodin, Podocalyxin, Fas, and FasL. The IL-17 and IL-1β expression in renal biopsy tissue was detected by immunohistochemistry. The expressions of WT1, Caspase 8, and Caspase 3 in podocyte cell culture were also measured using immunocytochemistry. Results: Circulating frequencies of Th17 cells, mRNA levels of RORc and IL-23p19, and serum levels of IL-6 and IL-1β were higher in the MCNS and NMCNS groups than in the control group (all P < 0.05), and were higher in the NMCNS group than in the MCNS group (all P < 0.05). The expressions of IL-17 and IL-1β in renal biopsy tissue were higher in the MCNS, MsPGN, and FSGS groups than in the control group (all P < 0.05). Recombinant murine IL-17 (rmIL-17) had no effect on the expressions of Nephrin, Synaptopodin, and WT1 of mouse podocytes, but caused an decrease in the expression of podocalyxin as well as promoted apoptosis in a dose- and time-dependent fashion. Moreover, rmIL-17 increased the expression of Fas, Casepase-8, and Casepase-3, but had no effect on that of FasL. Conclusion: Th17/IL-17 may contribute to the pathogenesis of PNS by decreasing the podocalyxin level and inducing podocyte apoptosis.

The effects of inflammation on lipid accumulation in the kidneys of children with primary nephrotic syndrome.

This study aimed to characterize the relationship between inflammation and lipid accumulation in children with primary nephrotic syndrome (PNS). Local expression of interleukin-1β (IL-1β), transforming growth factor-β1 (TGF-β1), low-density lipoprotein receptor (LDLr), sterol regulatory element binding protein-2 (SREBP-2), SREBP cleavage-activating protein (SCAP), and apolipoprotein B100 (apoB100) was analyzed by immunohistochemistry in kidney tissues obtained from children with PNS. Renal histopathology was evaluated by hematoxylin and eosin and periodic acid-Schiff staining. Serum levels of IL-1β and TGF-β1 were measured by enzyme-linked immunosorbent assays. Expression of IL-1β, TGF-β1, LDLr, SREBP-2, SCAP, and apoB100 was higher in samples from patients with non-minimal change necrotic syndrome (NMCNS) compared to both controls and patients with minimal change necrotic syndrome. Deposition of apoB100 was significantly correlated with expression of IL-1β, TGF-β1, LDLr, SREBP-2, and SCAP and with the glomerulosclerosis index, but not with plasma lipid levels. Expression of IL-1β and TGF-β1 was significantly correlated with expression of LDLr, SREBP-2, and SCAP. These findings suggest that inflammation leads to lipid accumulation in the kidney through disruption of the expression of proteins in the SCAP/SREBP-2/LDLr signaling pathway, which may underlie glomerulosclerosis and tubulointerstitial fibrosis in NMCNS.

IL-23 actived γδ T cells affect Th17 cells and regulatory T cells by secreting IL-21 in children with primary nephrotic syndrome

This study (1) analysed the percentage of γδ T cells, γδ T cell subsets, Th17 cells and regulatory T cells (Treg cells) and (2) determined the role of IL‐23 in primary nephrotic syndrome (PNS) patients with active disease and in remission. Eighty‐four patients with PNS and 51 healthy age‐matched controls were included in this study. The percentage of γδ T cells, γδ T cell subsets, Th17 cells and Treg cells in peripheral blood mononuclear cells (PBMCs) were analysed by fluorescence‐activated cell sorting. PMBCs from PNS patients with active disease were cultured in the presence of IL‐23, IL‐23 and an IL‐23 antagonist, or IL23 and an anti‐IL‐21 monoclonal antibody (mAb). The percentage of γδ T cells, IL‐23R+ γδ T cells and IL‐17+ γδ T cells were significantly increased in PNS patients with active disease. There was a positive correlation between the percentage of γδ T cells, IL‐23R+ γδ T cells, IL‐17+ γδ T cells and the Th17/Treg ratio. IL‐23 increased the percentage of γδ T cells and Th17 cells and decreased the percentage of Treg cells in PBMCs isolated from PNS patients with active disease. Anti‐IL‐21 mAb reduced the percentage of γδ T cells and Th17 cells, but increased the percentage of Treg cells. γδ T cells, IL‐17+ γδ T cells and IL‐23R+ γδ T cells may be involved in the pathogenesis of paediatric PNS by modulating the balance of Th17/Treg cells. γδ T cells may cause an imbalance in Th17/Treg cells by secreting IL‐21 in the presence of IL‐23.

Bartter Syndrome Type 3: Phenotype-Genotype Correlation and Favorable Response to Ibuprofen

Objective: To investigate the phenotype-genotype correlation in different genetic kinds of Bartter syndrome type 3 in children. Methods: Clinical and genetic data of 2 patients with different mutations in Bartter syndrome type 3 was analyzed while the prognosis was compared after a 6-year follow-up or 2-year follow-up, respectively. Results: Bartter syndrome is a kind of autosomal recessive inherited renal disorder. The manifestation and prognosis of Bartter syndrome change with mutation types, and severe mutation were often accompanied with unfavorable prognosis. Comprehensive therapy with ibuprofen, antisterone, captopril, and potassium have remarkable effect, while ibuprofen may improve growth retardation partly. Conclusion: Bartter syndrome should be considered when children have unreasonable continuous electrolyte disturbance, metabolic alkalosis and growth retardation.As a genetic disease, its clinical features depend on the mutation type. It can be ameliorated by electrolyte supplementation, prostaglandin synthetase inhibitors, angiotensin-converting enzyme inhibitors and potassium-sparing diuretic. Considering the following electrolyte disturbances, infections, growth retardation, kidney failure and even death, Bartter syndrome need lifelong treatment, early diagnosis and treatment is the most important.

Identification of a novel de novo gain-of-function mutation of PIK3CD in a patient with activated phosphoinositide 3-kinase δ syndrome

Activated phosphoinositide 3-kinase δ (PI3Kδ) syndrome is a newly defined and relatively common primary immunodeficiency, which is caused by heterozygous gain-of-function (GOF) mutations in PIK3CD or PIK3R1. Here, we report a novel de novo GOF mutation (c.1570 T > A, p.Y524N) in PIK3CD in a 6-year-old Chinese girl. The patient suffered recurrent sinopulmonary infection, bronchiectasis, lymphoproliferation, herpesvirus infection, and distinctive nodular lymphoid hyperplasia of mucosal surfaces. Immunological analysis revealed increased CD4+ T cell senescence and B cell immaturity. Further analysis revealed an increase in almost all CD4+ T cell subsets to varying degrees, including effector T cells and Treg cells. Increased levels of plasma T cell-related cytokines corroborated these results. Hyperactivation of the PI3Kδ-Akt-mTOR signaling pathway was also confirmed. Treatment with rapamycin ameliorated the lymphoproliferative immunodeficiency caused by hyperactivation of mTOR. These results expand genetic spectrum of APDS and will facilitate further study of the genotype-phenotype correlation in those with PIK3CD mutations.

γδT Cells Exacerbate Podocyte Injury via the CD28/B7-1-Phosphor-SRC Kinase Pathway

Primary nephrotic syndrome (PNS) is a devastating pediatric disorder. However, its mechanism remains unclear. Previous studies detected B7-1 in podocytes; meanwhile, γδT cells play pivotal roles in immune diseases. Therefore, this study aimed to assess whether and how γδT cells impact podocytes via the CD28/B7-1 pathway. WT and TCRδ−/− mice were assessed. LPS was used to induce nephropathy. Total γδT and CD28+γδT cells were quantitated in mouse spleen and kidney samples. B7-1 and phosphor-SRC levels in the kidney were detected as well. In vitro, γδT cells from the mouse spleen were cocultured with mouse podocytes, and apoptosis rate and phosphor-SRC expression in podocytes were assessed. Compared with control mice, WT mice with LPS nephropathy showed increased amounts of γδT cells in the kidney. Kidney injury was alleviated in TCRδ−/− mice. Meanwhile, B7-1 and phosphor-SRC levels were increased in the kidney from WT mice with LPS nephropathy. CD28+γδT cells were decreased, indicating CD28 may play a role in LPS nephropathy. Immunofluorescence colocalization analysis revealed a tight association of γδT cells with B7-1 in the kidney. High B7-1 expression was detected in podocytes treated with LPS. Podocytes cocultured with γδT cells showed higher phosphor-SRC and apoptosis rate than other cell groups. Furthermore, CD28/B7-1 blockage with CTLA4-Ig in vitro relieved podocyte injury. γδT cells exacerbate podocyte injury via CD28/B7-1 signaling, with downstream involvement of phosphor-SRC. The CD28/B7-1 blocker CTLA4-Ig prevented progressive podocyte injury, providing a potential therapeutic tool for PNS.

Expression of Fc Rs on monocytes among Kawasaki disease patients with coronary artery lesions

Objective: To study expression of Fc gamma receptors (Fc < gamma > Rs) on monocytes in Kawasaki disease (KD) patients with coronary artery lesions (CAL). Methods: 160 newly diagnosed KD patients and 80 health children were enrolled in this study. All patients were scheduled to receive both aspirin and intravenous immunoglobulin (IVIG). Serial blood samples were obtained before and 3 days after completing IVIG therapy. The first two‐dimensional echocardiographic examination was performed for all KD patients within 10 days, and was repeated at 3 weeks. CAL was defined by coronary artery Z‐scores ≥ 2.5 by echocardiography. Expression of inhibitory and activating Fc < gamma > Rs on CD14+ monocytes (MCs) was assessed by flow cytometry. Cytokine expression in MC was evaluated by PCR. Results: Of the 160 KD patients enrolled in this study, 36 had coronary artery lesions (KD‐CAL+ group), while 124 did not (KD‐CAL− group). There was no significant difference in Fc < gamma > RI expression on MCs from KD patients and that of Ctrls. Although Fc < gamma > RIII and Fc < gamma > RIIa levels were significantly higher in KD patients compared with those in Ctrls, there were no significant differences between the KD‐CAL+ and KD‐CAL− groups. Fc < gamma > RIIb expression in the KD patients was lower than that of Ctrls, meanwhile expression in the KD‐CAL+ group was lower than that in the KD‐CAL− group. After IVIG therapy, Fc < gamma > RIIb expression increased in KD‐CAL+, but did not reach the normal range. A negative correlation was observed between the levels of IL‐6, TNF‐&agr; and Fc < gamma > RIIb expression. Conclusion: Decreased Fc < gamma > RIIb expression on MCs may contribute to the development of coronary artery lesions in patients with KD.