Project description:The goal of the project was to identify risk alleles that are associated with recurrence of membranous nephropathy in the graft after kidney transplantation. First, we sequenced PLA2R1 and HLA-D loci in 248 patients with primary membranous nephropathy and identified two independent single nucleotide polymorphisms (SNPs) at risk for primary membranous nephropathy at each locus. Then we investigated whether primary membranous nephropathy at-risk variants were associated with recurrence in a retrospective cohort of 105 donor-recipient pairs and a replication cohort of 40 pairs.
Project description:Our understanding of the pathogenesis of idiopathic membranous nephropathy is limited by an incomplete molecular characterization of the cell types in the kidney and interaction between the cells. Besides, the reason for the heterogeneity of these patients as well as the variety of clinical outcomes remains elusive. Therefore, we applied scRNA-seq to kidney biopsies of patients with IMN to identify gene expression at the single-cell level, elucidate cells involved in the progression of IMN, and uncover intercellular interactions.
Project description:We report the expression of microRNAs in renal biopsies from patients with IgA nephropathy (progressive form and non progressive form), membranous and thin membrane nephropathies
Project description:Background: Multiple autoantigens have been identified in membranous nephropathy (MN) by tissue-based proteomics. However, the antigenic targets of disease are unknown for >10% of MN and >50% of membranous lupus nephritis (MLN) cases. We identified multiple new targets in PLA2R-/THSD7A-/EXT-/NELL1-quadruple negative MN biopsies through mass spectrometry (MS) of immune complexes recovered from biopsy tissue of patients with MN. Methods: MN cases negative for PLA2R, THSD7A, EXT1/2, and NELL1 were identified from a biopsy database. Protein G immunoprecipitation was used to recover immune complexes from frozen biopsy tissue, followed by interrogation by mass spectrometry (MS). Potential antigens were confirmed through paraffin immunofluorescence of protein targets, followed by co-localization with IgG within immune deposits. Consecutive series of 165 cases of PLA2R-negative MN biopsies and 95 MLN biopsies was screened to determine the frequency for each potential antigen. Results: Seven protein targets were discovered within immune complexes from MN biopsies including FCN3, CD206, EEA1, SEZ6L2, NPR3, MST1, and VASN. Peptides from these proteins on MS were not enriched in PLA2R (n=86), THSD7A (n=64), NELL1 (n=64), or EXT1/2 (n=60) controls. Between 3-30 unique peptides were detected for each target. Frequencies of each antigen, determined by staining consecutive case series, were SEZ6L2 (1/165 idiopathic; 0/95 MLN), VASN (8/165 idiopathic; 2/95 MLN), EEA1 (6/165 idiopathic; 7/95 MLN), MST1 (6/165 idiopathic; 2/95 MLN), and FCN3 (0/165 idiopathic, 6/95 MLN), NPR3 and CD206 were positive in index cases. All cases showed co-localization of IgG within immune deposits. Conclusion: Seven novel protein targets were identified in MN and MLN.
Project description:Background: Multiple autoantigens have been identified in membranous nephropathy (MN) by tissue-based proteomics. However, the antigenic targets of disease are unknown for >10% of MN and >50% of membranous lupus nephritis (MLN) cases. We identified multiple new targets in PLA2R-/THSD7A-/EXT-/NELL1-quadruple negative MN biopsies through mass spectrometry (MS) of immune complexes recovered from biopsy tissue of patients with MN. Methods: MN cases negative for PLA2R, THSD7A, EXT1/2, and NELL1 were identified from a biopsy database. Protein G immunoprecipitation was used to recover immune complexes from frozen biopsy tissue, followed by interrogation by mass spectrometry (MS). Potential antigens were confirmed through paraffin immunofluorescence of protein targets, followed by co-localization with IgG within immune deposits. Consecutive series of 165 cases of PLA2R-negative MN biopsies and 95 MLN biopsies was screened to determine the frequency for each potential antigen. Results: Seven protein targets were discovered within immune complexes from MN biopsies including FCN3, CD206, EEA1, SEZ6L2, NPR3, MST1, and VASN. Peptides from these proteins on MS were not enriched in PLA2R (n=86), THSD7A (n=64), NELL1 (n=64), or EXT1/2 (n=60) controls. Between 3-30 unique peptides were detected for each target. Frequencies of each antigen, determined by staining consecutive case series, were SEZ6L2 (1/165 idiopathic; 0/95 MLN), VASN (8/165 idiopathic; 2/95 MLN), EEA1 (6/165 idiopathic; 7/95 MLN), MST1 (6/165 idiopathic; 2/95 MLN), and FCN3 (0/165 idiopathic, 6/95 MLN), NPR3 and CD206 were positive in index cases. All cases showed co-localization of IgG within immune deposits. Conclusion: Seven novel protein targets were identified in MN and MLN.
Project description:Membranous lupus nephritis is a frequent cause of nephrotic syndrome in patients with systemic lupus erythematosus. Unlike phospholipase A2 receptor or thrombospondin type 1 domain containing 7A-associated membranous nephropathy, where known antibodies can be detected within sera by indirect immunofluorescence and/or enzyme-linked immunosorbent assay, it is not possible to monitor disease activity in membranous lupus nephritis where the target autoantigens are mostly unknown. Determination of the target autoantigen has diagnostic significance, informs prognosis, and allows for non-invasive monitoring of disease activity in serum. We utilized mass spectrometry for antigen discovery of laser capture microdissected glomeruli from formalin-fixed paraffin embedded tissue and tissue IgG immunoprecipitation studies from frozen kidney biopsy tissue. We identified neural cell adhesion molecule 1 (NCAM1) to be a target antigen in membranous lupus nephritis and within rare cases of primary membranous nephropathy. The prevalence of NCAM1-associated membranous neuropathy was 5.7% of cases of membranous lupus nephritis. NCAM1 co-localizes with IgG within glomerular immune deposits. Additionally, serum from NCAM1 patients showed reactivity to NCAM1 recombinant protein. The presence of anti-NCAM1 antibodies in sera could allow for non-invasive monitoring of the disease. We propose that NCAM1 is a target autoantigen in a subset of patients with membranous lupus nephritis. Future studies are needed to determine whether anti-NCAM1 antibody levels correlate with disease activity or response to therapy.