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: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
Project description:Idiopathic nephrotic syndrome (INS) is the most common primary glomerular disorder in children, yet the immunopathogenesis underlying steroid responsiveness remains incompletely understood. Here, we applied single-cell RNA sequencing to peripheral blood mononuclear cells obtained from three treatment-naïve children with steroid-sensitive nephrotic syndrome (SSNS) and one child with secondary steroid-resistant nephrotic syndrome (SRNS) at first relapse, all prior to immunosuppressive therapy.
Project description:INTRODUCTION: Idiopathic nephrotic syndrome (iNS) shows marked variability in treatment response, yet the molecular basis of multidrug resistance remains unclear. We hypothesized that multidrug-resistant nephrotic syndrome (MRNS) represents a distinct biological state rather than simply severe disease activity. METHODS: Serum proteomic profiling (LC–MS/MS) was performed in 165 pediatric and young adult patients with iNS, stratified by therapeutic phenotype (MRNS, steroid-dependent [SDNS], and multidrug-dependent [MDNS]). Differential protein expression was analyzed using pathway enrichment and machine learning–based approaches. Key biomarkers were validated by ELISA. Functional effects were evaluated in human podocytes exposed to patient-derived sera and in their peripheral blood mononuclear cells (PBMCs). RESULTS: Of 810 identified proteins, 322 differed significantly among groups. A 35-protein Random Forest signature discriminated MRNS from SDNS and MDNS. Integration of machine learning approaches identified dystroglycan 1 (DAG1), CD44 antigen (CD44), and RISC-loading complex subunit (TARBP2) as major contributors to group separation. Functional analyses revealed cytoskeletal disorganization, altered autophagy, inflammasome dysregulation, and increased endoplasmic reticulum stress in podocytes exposed to MRNS sera. A central mechanistic axis was the stress–survival imbalance with inverse regulation of the endoplasmic reticulum chaperon BIP (GRP78) and phosphorylated AKT (Ser473), a pattern also observed in peripheral blood mononuclear cells from MRNS patients. In contrast, sera from patients in remission showed phenotypes similar to those of healthy donors. CONCLUSIONS: MRNS represents a distinct molecular state characterized by systemic and organ-persistent stress activation and disrupted cellular homeostasis, whereas remission is characterized by a near-healthy profile. These findings support biomarker-guided stratification and therapeutic strategies aimed at restoring cellular balance rather than broadly suppressing immunity.
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:Background: Minimal change disease (MCD) and focal-segmental glomerulosclerosis (FSGS) are immune-mediated glomerular diseases manifesting as nephrotic syndrome. Autoantibodies against the podocyte slit diaphragm protein nephrin were recently identified in a subset of patients with minimal change disease, but their clinical and pathophysiological significance is largely unknown. Methods: Using immunoprecipitation assays, we performed a blinded screening for anti-nephrin antibodies in diagnostic and follow-up serum samples from adult patients with biopsy-proven MCD, FSGS, IgA nephropathy, and membranous nephropathy in comparison to healthy controls in two independent patient cohorts from Hamburg, Germany, and Bari, Italy. We further established a mouse model of anti-nephrin antibody-induced disease by active immunization using the recombinant murine nephrin ectodomain. Results: Anti-nephrin autoantibodies were detected in 50 of 110 (45%) patients with MCD, 8 of 107 (7%) patients with FSGS, 1 of 50 (2%) patients with membranous nephropathy, 0 of 48 (0%) patients with IgA nephropathy, and 0 of 67 (0%) healthy individuals. During follow-up, presence, and absence of anti-nephrin autoantibodies in patients with MCD and FSGS strongly correlated with active disease and remission, respectively. Immunization of mice induced anti-nephrin autoantibody formation and a highly dynamic phenotype with severe nephrotic syndrome and the histological features of MCD. Mechanistically, anti-nephrin autoantibodies induced nephrin phosphorylation at Tyr1191, cytoskeletal rearrangement, and downregulation of key podocyte proteins. Conclusion: Anti-nephrin antibodies are a valuable biomarker of disease activity in patients with MCD and FSGS, and binding of anti-nephrin antibodies at the podocyte slit diaphragm induces MCD with nephrotic syndrome.
Project description:Background: Minimal change disease (MCD) and focal-segmental glomerulosclerosis (FSGS) are immune-mediated glomerular diseases manifesting as nephrotic syndrome. Autoantibodies against the podocyte slit diaphragm protein nephrin were recently identified in a subset of patients with minimal change disease, but their clinical and pathophysiological significance is largely unknown. Methods: Using immunoprecipitation assays, we performed a blinded screening for anti-nephrin antibodies in diagnostic and follow-up serum samples from adult patients with biopsy-proven MCD, FSGS, IgA nephropathy, and membranous nephropathy in comparison to healthy controls in two independent patient cohorts from Hamburg, Germany, and Bari, Italy. We further established a mouse model of anti-nephrin antibody-induced disease by active immunization using the recombinant murine nephrin ectodomain. Results: Anti-nephrin autoantibodies were detected in 50 of 110 (45%) patients with MCD, 8 of 107 (7%) patients with FSGS, 1 of 50 (2%) patients with membranous nephropathy, 0 of 48 (0%) patients with IgA nephropathy, and 0 of 67 (0%) healthy individuals. During follow-up, presence, and absence of anti-nephrin autoantibodies in patients with MCD and FSGS strongly correlated with active disease and remission, respectively. Immunization of mice induced anti-nephrin autoantibody formation and a highly dynamic phenotype with severe nephrotic syndrome and the histological features of MCD. Mechanistically, anti-nephrin autoantibodies induced nephrin phosphorylation at Tyr1191, cytoskeletal rearrangement, and downregulation of key podocyte proteins. Conclusion: Anti-nephrin antibodies are a valuable biomarker of disease activity in patients with MCD and FSGS, and binding of anti-nephrin antibodies at the podocyte slit diaphragm induces MCD with nephrotic syndrome.
Project description:Genome wide DNA methylation profiling of obstructive sleep apnea (OSA) patients and healthy subjects. The Illumina Infinium 27k Human DNA methylation Beadchip v1.2 was used to obtain DNA methylation profiles across approximately 27,000 CpGs in peripheral blood mononuclear cell samples. Samples included 8 normal subjects and 16 patients with obstructive sleep apnea syndrome.