Project description:Glucocorticoid resistance complicates the treatment of ~20% of children with nephrotic syndrome, yet the molecular basis for resistance remains unclear. We generated the transcriptome profile by RNA sequencing of peripheral blood leukocytes from children obtained both at initial nephrotic syndrome presentation and after ~7 weeks of glucocorticoid therapy to identify genes or a gene panel able to differentiate steroid sensitive from steroid resistant nephrotic syndrome. RNA -seq analysis was followed by in-silico algorithm-based approaches and subsequent biochemical analyses on relevant candidate gene with important roles in podocyte and glomerular pathophysiology, using both patient samples and experimental models of nephrotic syndrome and podocyte injury.
Project description:This study aimed to evaluate gene expression patterns in urinary sediment samples of children with steroid-resistant nephrotic syndrome (SRNS).
Project description:Pathology consensus review for clinical trials and disease classification has historically been performed by manual light microscopy with sequential section review by study pathologists, or multi-headed microscope review. Limitations of this approach include high intra- and inter-reader variability, costs, and delays for slide mailing and consensus reviews. To improve this, the Nephrotic Syndrome Study Network (NEPTUNE) is systematically applying digital pathology review in a multicenter study using renal biopsy whole slide imaging (WSI) for observation-based data collection. Study pathology materials are acquired, scanned, uploaded, and stored in a web-based information system that is accessed through a web-browser interface. Quality control includes metadata and image quality review. Initially, digital slides are annotated, with each glomerulus identified, given a unique number, and maintained in all levels until the glomerulus disappears or sections end. The software allows viewing and annotation of multiple slide sections concurrently. Analysis utilizes "descriptors" for patterns of injury, rather than diagnoses, in renal parenchymal compartments. This multidimensional representation via WSI, allows more accurate glomerular counting and identification of all lesions in each glomerulus, with data available in a searchable database. The use of WSI brings about efficiency critical to pathology review in a clinical trial setting, including independent review by multiple pathologists, improved intraobserver and interobserver reproducibility, efficiencies and risk reduction in slide circulation and mailing, centralized management of data integrity and slide images for current or future studies, and web-based consensus meetings. The overall effect is improved incorporation of pathology review in a budget neutral approach.
Project description:Rationale & objectiveSurrogate outcomes for end-stage kidney disease often assume linear changes, which may not reflect true estimated glomerular filtration rate (eGFR) trajectories. This study's objective was to characterize nonlinear eGFR trajectories in nephrotic syndrome.Study designObservational cohort study.Setting & participantsNephrotic Syndrome Study Network (NEPTUNE) is a multicenter study of adult and pediatric patients with proteinuria enrolled at clinically indicated kidney biopsy or initial presentation of disease (pediatric only).PredictorsPatient demographic, clinical, and pathology variables at study enrollment and follow-up time.OutcomeeGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration (patients ≥ 18 years old) or modified Chronic Kidney Disease in Children Study-Schwartz (patients < 18 years) formulas. The probability of nonlinearity (PNL) was calculated for individual eGFR trajectories.Analytical approachAssociations between predictors and PNL were assessed using multivariable linear regression.Results453 patients with ≥3 eGFR measurements and 1 or more year of follow-up were included (median follow-up, 3.6 years). Median PNL was 0.052; 56% and 16% had PNL < 10% and >50%, respectively. In both adults and pediatric patients, higher baseline eGFR was associated with higher PNL, whereas longer follow-up time was associated with lower PNL. Higher urine protein-creatinine ratio and steroid use were also associated with higher PNL in adults. Higher percentages of tubular atrophy and foot-process effacement were associated with lower and higher PNLs, respectively, in adults.LimitationsRelatively short follow-up time, inability to assess acute kidney injury events, and variable eGFR measurement frequency across patients.ConclusionsAlthough increasing follow-up time resulted in more linear trajectories, nonlinear eGFR trajectories were common in this cohort. Future studies in nephrotic syndrome should consider novel outcomes that do not rely on linearity assumptions.
Project description:Background: Minimal change nephrotic syndrome (MCNS) is considered to be associated with T cell dysfunction, via unknown mechanisms. Experimental observations suggest that some humoral factors alter the permeability of glomerular filtration barrier. However, the nature of such factors remains still uncertain. Methods: Using cDNA microarrays, we performed gene expression profiling of peripheral blood mononuclear cells (PBMC) from three patients with MCNS during nephrosis and remission phases. To confirm the cDNA microarray results, we performed quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) analyses in nephrosis and remission samples from 20 MCNS patients and six patients with nephrotic syndrome due to membranous nephropathy. Results: Out of 24,446 genes screened, 33 genes were up-regulated (at least 1.5-fold) in PBMC from these MCNS patients during the nephrosis phase. Up-regulated genes mainly encoded proteins involved in signal transduction and cytokine response. For further examination, we selected two genes encoding provable secretary proteins, chemokine (C-C) ligand 13 (also known as monocyte chemotactic protein-4) (CCL13) and a novel galectin-related protein (HSPC159). The results of RT-PCR showed that expressions of CCL13 and HSPC159 mRNA in nephrosis PBMC samples are higher than those in remission PBMC samples from all 20 MCNS patients examined. On the other hand, these mRNA expression patterns were variable among six patients with membranous nephropathy. Conclusions: We conclude that CCL13 and HSPC159 mRNA expressions in PBMC is up-regulated in MCNS patients during the nephrosis phase. These expression changes in PBMC might be involved in the pathophysiologic processes of MCNS. Using cDNA microarrays, we performed gene expression profiling of peripheral blood mononuclear cells (PBMC) from three patients with MCNS during nephrosis and remission phases. To confirm the cDNA microarray results, we performed quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) analyses in nephrosis and remission samples from 20 MCNS patients and six patients with nephrotic syndrome due to membranous nephropathy.
Project description:The Nephrotic Syndrome Study Network (NEPTUNE) is a North American multicenter collaborative consortium established to develop a translational research infrastructure for nephrotic syndrome. This includes a longitudinal observational cohort study, a pilot and ancillary study program, a training program, and a patient contact registry. NEPTUNE will enroll 450 adults and children with minimal change disease, focal segmental glomerulosclerosis, and membranous nephropathy for detailed clinical, histopathological, and molecular phenotyping at the time of clinically indicated renal biopsy. Initial visits will include an extensive clinical history, physical examination, collection of urine, blood and renal tissue samples, and assessments of quality of life and patient-reported outcomes. Follow-up history, physical measures, urine and blood samples, and questionnaires will be obtained every 4 months in the first year and biannually, thereafter. Molecular profiles and gene expression data will be linked to phenotypic, genetic, and digitalized histological data for comprehensive analyses using systems biology approaches. Analytical strategies were designed to transform descriptive information to mechanistic disease classification for nephrotic syndrome and to identify clinical, histological, and genomic disease predictors. Thus, understanding the complexity of the disease pathogenesis will guide further investigation for targeted therapeutic strategies.
Project description:Background: Minimal change nephrotic syndrome (MCNS) is considered to be associated with T cell dysfunction, via unknown mechanisms. Experimental observations suggest that some humoral factors alter the permeability of glomerular filtration barrier. However, the nature of such factors remains still uncertain. Methods: Using cDNA microarrays, we performed gene expression profiling of peripheral blood mononuclear cells (PBMC) from three patients with MCNS during nephrosis and remission phases. To confirm the cDNA microarray results, we performed quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) analyses in nephrosis and remission samples from 20 MCNS patients and six patients with nephrotic syndrome due to membranous nephropathy. Results: Out of 24,446 genes screened, 33 genes were up-regulated (at least 1.5-fold) in PBMC from these MCNS patients during the nephrosis phase. Up-regulated genes mainly encoded proteins involved in signal transduction and cytokine response. For further examination, we selected two genes encoding provable secretary proteins, chemokine (C-C) ligand 13 (also known as monocyte chemotactic protein-4) (CCL13) and a novel galectin-related protein (HSPC159). The results of RT-PCR showed that expressions of CCL13 and HSPC159 mRNA in nephrosis PBMC samples are higher than those in remission PBMC samples from all 20 MCNS patients examined. On the other hand, these mRNA expression patterns were variable among six patients with membranous nephropathy. Conclusions: We conclude that CCL13 and HSPC159 mRNA expressions in PBMC is up-regulated in MCNS patients during the nephrosis phase. These expression changes in PBMC might be involved in the pathophysiologic processes of MCNS. Keywords: CCL13 - cDNA microarray - gene expression profile - HSPC159 - minimal change nephrotic syndrome