Effects of peritoneal effluents on mesothelial cells in culture: Cell proliferation and extracellular matrix regulation

F. Perfumo, P. Altieri, M. L. Degl'Innocenti, G. M. Ghiggeri, G. Caridi, A. Trivelli, R. Gusmano

Research output: Contribution to journalArticle

Abstract

Abstract Peritoneal fibrosis in patients on peritoneal dialysis is the result of interstitial collagen accumulation within the peritoneal membrane and in mural spaces. Hypothetically, collagen expression by target cells may be regulated by specific endoperitoneal factors, though the existence of such factors has not yet been demonstrated. We evaluated the effects of cell-free peritoneal effluents obtained from six children undergoing peritoneal dialysis on several mesothelial cell functions in vitro. Human peritoneal mesothelial cells (MC) were obtained from the omental tissue of six uraemic children who were undergoing surgery for insertion of a peritoneal catheter. Cells at confluence were utilized to determine cytotoxicity (LDH release), viability (trypan blue), proliferation (3H-thymidine incorporation), collagen expression (3H-proline incorporation, SDS-Page) and mRNA (dot-blot). A preliminary series of experiments, was undertaken to define which of the successive fluid collections during a dialytic procedure induces the greatest changes; this revealed maximal effects of the effluent from the long stasis period. Exposure to peritoneal effluents obtained from four patients with acute peritonitis induced marked changes in cell morphology, stimulated by (3H)-thymidine incorporation into DNA by 300% and upregulated the expression and transcription of type III collagen (6-fold increment in COL3A1 mRNA). Qualitatively but not quantitatively comparable changes in cell proliferation (+100%) and collagen expression were induced by peritoneal effluents from patients without peritonitis. In an effort to reproduce the effect of peritoneal effluents in vitro, we exposed mesothelial cells to various cytokines putatively present in infected peritoneal effluents, namely IL-2, TGFβ and TNFα; in no case did we find stimulation of cell proliferation. Finally TGFβ but not TNFα. or IL2 upregulated collagen synthesis by these cells. These findings demonstrate a direct influence of cell-free peritoneal effluents on mesothelial cell functions, including stimulation of interstitial collagen expression. All these changes were more evident upon exposure to effluents collected during acute peritonitis, which suggests a link between recurrent peritoneal infection and collagen deposition, the most typical precursor of peritoneal fibrosis.

Original languageEnglish
Pages (from-to)1803-1809
Number of pages7
JournalNephrology Dialysis Transplantation
Volume11
Issue number9
Publication statusPublished - Sep 1996

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Keywords

  • Collagen
  • Fibrosis
  • Peritoneal dialysis
  • Peritonitis

ASJC Scopus subject areas

  • Nephrology
  • Transplantation

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