Epithelial to mesenchymal transformation in tubular epithelial cells undergoing anoxia

Transplant Proc. 2008 Oct;40(8):2800-3. doi: 10.1016/j.transproceed.2008.08.004.

Abstract

Aim: Epithelial-mesenchymal transformation (EMT) has been proved to be a critical event in fibrogenesis of renal allografts. This study sought to determine whether anoxia could induce EMT from tubular epithelial cells (TEC).

Methods: Rat TEC-line (NRK-52E) was cultured in Dulbelco's modified Eagle's medium (DMEM) without glucose under 100% N2 for 4 hours. After 6, 12, 24, 48, and 72 hours, the expressions of connective tissue growth factor (CTGF) mRNA and protein were measured by real-time RT-PCR and Western blot, respectively. Morphologic changes and cytoskeleton remodeling were observed in NRK-52E cells under laser confocal microscopy. Immunohistochemistry and flow cytometry were used to detect expression changes of E-cadherin, alpha-smooth muscle actin (SMA), types I and IV collagen, all of which are involved in TEC, EMT.

Results: After stimulation by anoxia, NRK-52E cells became round and enlarged with a remodeled cytoskeleton. The expressions of CTGF mRNA and protein were upregulated after 6 hours, reaching their peak at 48 hours. The expressions of types I and IV collagen, and alpha-SMA were all upregulated except for E-cadherin.

Conclusions: Anoxia upregulated the expression of CTGF and other EMT-associated genes in NRK-52E cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / genetics
  • Animals
  • Cell Culture Techniques
  • Cell Differentiation / physiology*
  • Cell Hypoxia / physiology*
  • Cell Line
  • Collagen Type I / genetics
  • Collagen Type IV / genetics
  • Connective Tissue Growth Factor / genetics
  • DNA Primers
  • Epithelial Cells / cytology*
  • Epithelial Cells / physiology
  • Gene Expression Regulation
  • Insulin-Like Growth Factor Binding Proteins / genetics
  • Kidney
  • Mesoderm / cytology*
  • Mesoderm / physiology
  • RNA, Messenger / genetics
  • Rats

Substances

  • Actins
  • Collagen Type I
  • Collagen Type IV
  • DNA Primers
  • Insulin-Like Growth Factor Binding Proteins
  • RNA, Messenger
  • smooth muscle actin, rat
  • Connective Tissue Growth Factor