ASN's Mission

ASN leads the fight to prevent, treat, and cure kidney diseases throughout the world by educating health professionals and scientists, advancing research and innovation, communicating new knowledge, and advocating for the highest quality care for patients.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on Twitter

Kidney Week

Abstract: PO1289

HAS2 Expression as a Novel Mechanism of TGF-β-Induced Phenotype Transition of Human Peritoneal Mesothelial Cells

Session Information

Category: Dialysis

  • 703 Dialysis: Peritoneal Dialysis

Authors

  • Kang, Hyun-Jung, Ewha Womans University, Seoul, Korea (the Republic of)
  • Kim, Dal-ah, Ewha Womans University, Seoul, Korea (the Republic of)
  • Je, Cheongran, Ewha Womans University, Seoul, Korea (the Republic of)
  • Kang, Duk-Hee, Ewha Womans University, Seoul, Korea (the Republic of)
Background

Epithelial-to-mesenchymal transition (EMT) of human peritoneal mesothelial cells is one of the key mechanisms of peritoneal fibrosis in peritoneal dialysis (PD), which can be reversible at early stage of phenotype transition. Therefore, the identification of novel molecular biomarkers of peritoneal EMT may facilitate the diagnosis of peritoneal damage allowing early initiation of treatment targeting peritoneal fibrosis. Hyaluronan (HA) is a glycosaminoglycan component of the extracellular matrix, produced by three members of HA synthase (HAS1, HAS2 and HAS3). HAS are known to be involved in EMT of cancer cells, however there is no information on the association of HAS and peritoneal EMT.

Methods

Peritoneal MCs isolated from overnight dwell dialysates from 16 PD patients (PD_MC) at 2 [baseline peritoneal equilibration test (PET)] and 6 (follow-up PET) months of the PD initiation. We divided PD patients into two groups based on the alteration of baseline and follow-up PD_MC morphology (Group 1 epithelial-epithelial and Group 2 epithelial-mesenchymal). RNA-seq analysis (Ebiogen, Korea) was performed in order to detect baseline molecular markers predicting mesenchymal phenotype in follow-up. Based on RNA-seq analysis, the expressions of HAS isoform were evaluated in MCs isolated from omentum (OM_MC) with an exploration of the role of HAS on TGFβ-induced EMT.

Results

RNA-seq analysis demonstrated the difference of gene expression related to EMT (27.6%), angiogenesis (30.2 %), cell migration (27.4%), and extracellular matrix remodeling (26.3%). Among them, HAS2 expression in baseline analysis showed the highest fold difference (28.5-folds) between group 1 and 2. In OM-MC, HAS1, HAS2 and HAS3 were constitutively expressed whereas only HAS1 and HAS2 were upregulated by TGFβ. TGFβ-induced changes in cell morphology and the expression of E-cadherin, α-SMA, and fibronectin were ameliorated by siHAS2, but not by siHAS1. HAS inhibitor (4-methylumbelliferone; 4-MU) also alleviated TGFβ-induced EMT.

Conclusion

This data suggest HAS2 plays a role in TGFβ-induced EMT of peritoneal mesothelial cells and modulation of HAS2 can protect the peritoneal fibrosis in PD patients. Both HA or HAS2 in peritoneal effluent of baseline PET also can be the markers predicting peritoneal EMT and fibrosis.