Single Nuclei Transcriptomics Delineates Complex Interactions Between Immune and Renal Cells Contributing to Kidney Graft Fibrosis
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ABSTRACT: Purpose: Chronic allograft dysfunction (CAD) remains a major obstacle in kidney transplantation. However, the molecular pathogenesis of human CAD is unknown. Herein, we tested the hypothesis that single nuclei transcriptomics of human kidney allograft fibrosis will reveal diverse cell types, deconvolve complex fibrosis-driving pathways, and provide deeper insights into the progression of kidney allograft dysfunction.
Project description:The molecular basis of calcineurin inhibitor toxicity (CNIT) in kidney transplantation (KT) and its contribution to chronic allograft dysfunction (CAD) with interstitial fibrosis (IF) and tubular atrophy (TA) were evaluated. Molecular signatures characterizing CNIT samples were identified. The recognized CNIT gene signature was most common in patients with decreased graft function and histological evidence of IF/TA. To test CNIT contribution to CAD progression, kidney biopsies from transplant recipients with histological diagnosis of CNIT (n=14), acute rejection (ACR, n=13), and CAD with IF/TA (n=10), including 18 Normal allografts, were analyzed using gene expression microarrays.
Project description:The molecular basis of calcineurin inhibitor toxicity (CNIT) in kidney transplantation (KT) and its contribution to chronic allograft dysfunction (CAD) with interstitial fibrosis (IF) and tubular atrophy (TA) were evaluated. Molecular signatures characterizing CNIT samples were identified. The recognized CNIT gene signature was most common in patients with decreased graft function and histological evidence of IF/TA.
Project description:Most kidney allograft losses are caused by chronic allograft dysfunction (CAD) that is characterized by interstitial fibrosis, tubular atrophy and a smoldering inflammatory process. The aim of the study was to correlate changes in gene expression over time, as evidenced by effects on regulatory pathways linked to the development of fibrosis and inflammation during the development of chronic damage. Renal allografts were harvested for time points 0d, 7d, 14d and 56d (n=3-5) and examined for steady state mRNA expression using Affymetrix microarray RG-U34A. A select group of genes previously associated with chronic fibrosis was then examined in the context of progressive dysfunction. In order to verify the microarray analysis, qPCR has been performed. Microarray data was used to obtain transcriptomic changes reflecting signaltransduction pathway dysregulation Timecourse results (log2 placebo/control) linked below as supplementary files. Keywords: timecourse analysis
Project description:Tolerance of mouse kidney allografts arises in grafts that develop regulatory Tertiary Lymphoid Organs (rTLOs). scRNAseq data and adoptive transfer of alloreactive T cells post-transplant showed that cytotoxic CD8+ T cells are reprogrammed within the accepted graft to an exhausted/regulatory-like phenotype. Establishment of rTLOs was required since adoptive transfer of alloreactive T cells prior to transplantation results in kidney allograft rejection. Despite intragraft CD8+ cells with a regulatory phenotype, they were not essential for the induction and maintenance of kidney allograft tolerance. Analysis of scRNAseq data from allograft kidneys and malignant tumors identified similar regulatory-like cell types within the T cell clusters. Induction of cytotoxic CD8+ T cell dysfunction of infiltrating cells appears to be a beneficial mechanistic pathway that protects the kidney allotransplant from rejection through a process we call “defensive tolerance.” This pathway has implications for our understanding of allotransplant tolerance and tumor resistance to host immunity.
Project description:Most kidney allograft losses are caused by chronic allograft dysfunction (CAD). The aim of the study was to correlate changes in gene expression over time during the development of chronic damage in contrast to13cisRA Treated animal that demonstrated morphologically healthy kidneys by the end of teh study. Renal allografts were harvested from placebo and13cisRA Treatment groups for time points 0d, 7d, 14d and 56d (n=3-5) and examined for steady state mRNA expression using Affymetrix microarray RG-U34A. The effect of the13cisRA Treatment on dysregulated pathways was examined. In order to verify the microarray analysis, qPCR has been performed. Microarray data was used to obtain transcriptomic changes reflecting signaltransduction pathway dysregulation Progression of rejection was observed in untreated animals at timepoints 7d, 14d and 56d after transplantation that could be prevented by 13cisRA treatment
Project description:Most kidney allograft losses are caused by chronic allograft dysfunction (CAD). The aim of the study was to correlate changes in gene expression over time during the development of chronic damage in contrast to13cisRA Treated animal that demonstrated morphologically healthy kidneys by the end of teh study. Renal allografts were harvested from placebo and13cisRA Treatment groups for time points 0d, 7d, 14d and 56d (n=3-5) and examined for steady state mRNA expression using Affymetrix microarray RG-U34A. The effect of the13cisRA Treatment on dysregulated pathways was examined. In order to verify the microarray analysis, qPCR has been performed. Microarray data was used to obtain transcriptomic changes reflecting signaltransduction pathway dysregulation
Project description:The Australian Chronic Allograft Dysfunction (AUSCAD) study is an ongoing single centre cohort study at Westmead hospital in Australia. In this section of the study, we aimed to identify biomarkers for chronic allograft dysfunction in kidney transplant recipients. Our study recruited 136 patients, each having protocol renal allograft biopsies taken pre transplantation.
Project description:The study comprises various components: Samples TD: We aims to screen out different gene expression profile in donor biopsies after revascularization , We aims to predict renal allograft dysfunction early after transplantation. Samples AR, ATN, Tx: We aim to screen out different gene expression profile in acute rejection on the kidney. We aim to screen out different gene expression profile in acute tubular necrosis on the kidney. Results from the various study components can help to diagnose renal allograft dysfunction with different causes by distinct gene expression profile. Keywords: acute rejection, acute tubular necrosis, donor biopsies, renal allograft dysfunction