Peritoneal dialysis (PD) is a life-saving form of renal replacement therapy for those with End Stage Kidney Disease. Peritoneal fibrosis is a considerable problem for PD patients, and mesothelial cells, which line the peritoneal cavity, play a central role in response to injury and fibrogenesis within the peritoneum. Mesothelial cells may undergo mesothelial to mesenchymal transition (MMT) contributing to peritoneal fibrosis and treatment failure. miRNAs are important regulators of fibrosis but their roles in peritoneal fibrosis are largely unknown. Here, a detailed characterization of the MMT process was performed in primary human mesothelial cells (HPMCs) in response to Transforming Growth Factor beta-1 (TGF-β1). Hybridization array showed mesothelial miR-21 and miR-31 expression was up-regulated by TGF-β1 which was validated by RTqPCR in different PD associated MMT models. Mesothelial cells cultured ex vivo from PD patients exhibited phenotypic changes consistent with a progressive MMT process that correlated with an increase in miR-21 and miR-31 expression. Association of miRNA expression and MMT markers in 33 peritoneal biopsies from patients undergoing PD treatment and in PD effluent from 230 PD patients confirmed these results. In silico analysis combined 4 target prediction algorithms (Targetscan, miRanda, miRDB and Diana-microT) for miR-21 and integrated the resulting outcome with mRNA arrays comparing omentum vs PD effluent-derived HPMCs with epithelial (E) and non-epithelial (NE) phenotype. 13 possible miR-21 targets during the MMT process associated to PD therapy were identified and model scrutinized. Four of these were confirmed to be miR- 21 targets. Functional gene analysis indicated that selected targets may be downstream modulators of Snail and cooperate driving MMT during peritoneal fibrosis. Taken together, these data provide a detailed characterisation of mesothelial miRNA expression and responses to TGF-β1, and identify miR-21 and miR-31 as promising biomarkers for peritoneal fibrosis associated to PD therapy.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:699397 |
| Date | January 2017 |
| Creators | Lopez Anton, Melisa |
| Publisher | Cardiff University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://orca.cf.ac.uk/95953/ |
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