Project description:Peritoneal dialysis (PD) is an effective form of renal replacement therapy. A significant proportion of patients who initiate PD suffer from PD-related clinical complications, including peritoneal membrane damage, which may limit the duration of treatment. Mesothelial-to-mesenchymal transition (MMT) significantly contributes to the peritoneal dysfunction related to PD. Hence, we analyzed the genetic reprograming of the MMT-process with the aim to identify new biomarkers that may be tested in PD-patients. Microarray analysis revealed a partial overlapping of MMT induced in vitro and MMT of effluent-derived mesothelial cells (ex vivo), and that MMT, both in vitro and ex vivo, is mainly a repression process being higher the number of genes that are down-regulated than those that are induced. According to cellular morphology and the number of altered genes and pathways, the MMT ex vivo could be subdivided into two stages: early/epitheliod and advanced/non-epitheliod. We could demonstrate by RT-PCR array analysis that a number of genes differentially expressed in effluent-derived non-epitheliod cells also showed significant differential expression when comparing standard versus low-GDP PD fluids. Among the secreted proteins that are up-regulated along the MMT process thrombospondin-1 (TSP1), collagen-13 (COL13), vascular endothelial growth factor A (VEGFA), and gremlin-1 (GREM1) were selected to be measured in PD effluents. TSP1, COL13 and VEGFA, but not GREM1, showed significant differences between early and advanced stages of MMT, and their expression were associated with high peritoneal transport status. The results establish a proof of concept about the feasibility of MMT-associated secreted proteins as biomarkers in PD.
Project description:Peritoneal dialysis (PD) is an effective form of renal replacement therapy. A significant proportion of patients who initiate PD suffer from PD-related clinical complications, including peritoneal membrane damage, which may limit the duration of treatment. Mesothelial-to-mesenchymal transition (MMT) significantly contributes to the peritoneal dysfunction related to PD. Hence, we analyzed the genetic reprograming of the MMT-process with the aim to identify new biomarkers that may be tested in PD-patients. Microarray analysis revealed a partial overlapping of MMT induced in vitro and MMT of effluent-derived mesothelial cells (ex vivo), and that MMT, both in vitro and ex vivo, is mainly a repression process being higher the number of genes that are down-regulated than those that are induced. According to cellular morphology and the number of altered genes and pathways, the MMT ex vivo could be subdivided into two stages: early/epitheliod and advanced/non-epitheliod. We could demonstrate by RT-PCR array analysis that a number of genes differentially expressed in effluent-derived non-epitheliod cells also showed significant differential expression when comparing standard versus low-GDP PD fluids. Among the secreted proteins that are up-regulated along the MMT process thrombospondin-1 (TSP1), collagen-13 (COL13), vascular endothelial growth factor A (VEGFA), and gremlin-1 (GREM1) were selected to be measured in PD effluents. TSP1, COL13 and VEGFA, but not GREM1, showed significant differences between early and advanced stages of MMT, and their expression were associated with high peritoneal transport status. The results establish a proof of concept about the feasibility of MMT-associated secreted proteins as biomarkers in PD.
Project description:Peritoneal fibrosis is a major complication of long-term peritoneal dialysis (PD), leading to ultrafiltration failure and sometimes life threatening encapsulating peritoneal sclerosis. Fibrosis is driven by activated myofibroblasts that are derived, in part, from mesothelial-to-mesenchymal transition (MMT). We aimed to discover novel mediators of MMT and then experimentally exploit them to prevent peritoneal fibrosis. Using an antibody to HBME-1 and streptavidin nanobead technology, we first pioneered a novel method to purify rat mesothelial cells. After exposing mesothelial cells to transforming growth factor β1 (TGFβ1), we undertook RNAseq whole transcriptome analyses and outlined, the expression profile of sorted mesothelial cells at pre- and post- MMT.
Project description:Cardiac fibrosis is a detrimental pathophysiological state involved in a number of cardiovascular diseases. Myofibroblasts mediate fibrosis by excessive remodeling of the extracellular matrix, which ultimately leads to tissue stiffness and impaired heart performance. Recently, it was shown that a substantial fraction of cardiac myofibroblasts may originate from the epicardium through Epithelial-to-Mesenchymal Transition (EMT). We have developed a cellular model of EMT in which adult murine epicardium-derived cells are differentiated into myofibroblast-like cells in the presence of Interleukin-1beta, Tumor Necrosis Factor-alpha, or Transforming Growth Factor-beta. Using this model of EMT, the microRNAome was assessed by microRNA (miRNA) arrays. Subsequently, expression levels of differentially expressed miRNAs were validated by qPCR. These miRNAs were targeted by transfecting epicardium-derived cells with anti- or pre-miRs prior to EMT initiation. The ability of the anti- or pre-miRs to inhibit EMT was assessed on a number of phenotypic markers. In this study we have identified a number of miRNAs that potentially play an intrinsic role in cardiac EMT. We speculate that by targeting those miRNA, the onset and long-term progression of cardiac fibrosis can be substantially reduced. Epicardial mesothelial cells were isolated and expanded from the epicardium of adult rats (8-10 weeks). Epithelial-to-mesenchymal Transition was induced by 10 ng/mL Interleukin-1beta, Tumor Necrosis Factor-alpha, or Transforming Growth Factor-beta1 for 48h. The assocciated differential microRNA expressions relative to a control treatment was computed by microRNA arrays. The experiment was conducted on biological quadruplicates for the control treatment and biological triplicates for cytokine treatments.
Project description:In chronic liver diseases, hepatic stellate cells (HSCs) are induced to form the myofibroblasts responsible for scar formation, leading to liver fibrosis and cirrhosis. Here, single-cell RNA sequencing with in vivo lineage tracing in non-alcoholic steatohepatitis (NASH) model mice reveals a subpopulation of HSCs transitioning back to a state resembling their developmental precursors, mesothelial cells (MCs), after liver injury. These damage-associated intermediates between HSCs and MCs (DIHMs) can be traced with a dual recombinase system by labeling Krt19-expressing cells within pre-labeled Pdgfrb-positive HSCs, and DIHMs highly express inflammation- and fibrosis-associated genes. Cre and Dre-inducible depletion of DIHMs by administering diphtheria toxin reduces liver fibrosis and alleviates liver damage in NASH model mice. Importantly, knockdown of Osr1, a zinc finger transcription factor of the OSR gene family, can block DIHM induction in vitro. Conditional knockout Osr1 in Pdgfrb-expressing mesenchymal cells in NASH model mice can reduce liver fibrosis in vivo. Our study collectively uncovers an injury-induced developmental reversion process wherein HSCs undergo what we term a mesenchymal-to-mesothelial transition (MMesoT), which can be targeted to develop interventions to treat chronic liver diseases.
Project description:RNA-sequencing analysis was carried out on ascetic fluid-isolated mesothelial cells from ovarian cancer patients compared to control human peritoneal mesothelial cells to identify a mesothelial-mesenchymal gene signature.
Project description:Despite their emerging relevance to fully understand disease pathogenesis, we have as yet a poor understanding as to how biomechanical signals are integrated with specific biochemical pathways to determine cell behaviour. Mesothelial-to-mesenchymal transition (MMT) markers colocalized with TGF-beta1-dependent signalling and yes-associated protein (YAP) activation across biopsies from different pathologies exhibiting peritoneal fibrosis, supporting mechanotransduction as a central driving component of these class of fibrotic lesions and its crosstalk with specific signaling pathways. Transcriptome and proteome profiling of the response of mesothelial cells (MCs) to linear cyclic stretch revealed molecular changes compatible with bona fide MMT, which (i) overlapped with established YAP target gene subsets, and (ii) were largely dependent on endogenous TGF-beta1 signaling. Importantly, TGF-beta1 blockade blunts the transcriptional upregulation of the se gene signatures, but not the mechanical activation and nuclear translocation of YAP per se. We studied the role therein of caveolin-1 (Cav1), a plasma membrane mechanotransducer. Exposure of Cav1-deficient MCs to cyclic stretch led to a robust upregulation of MMT-related gene programs, which was blunted upon TGF-beta1 inhibition. Conversely, Cav1 depletion enhanced both TGF-beta1 and TGFBRI expression. Cav1 genetic deficiency exacerbated MMT and PA fibrosis in an experimental model of peritoneal ischaemic buttons. Taken together, these results support that Cav1-YAP/TAZ fine-tune the fibrotic response through the modulation of MMT, onto which TGF-beta1-dependent signaling coordinately converges. Our findings reveal a cooperation between biomechanical and biochemical signals in the triggering of MMT, representing a novel potential opportunity to intervene mechanically-induced disorders coursing with peritoneal fibrosis, such as post-surgical adhesions. This SuperSeries is composed of the SubSeries listed below.