Cyclosporin-A induced toxicity in rat renal collecting duct cells: interference with enhanced hypertonicity induced apoptosis

Cell Physiol Biochem. 2010;26(6):887-900. doi: 10.1159/000323998. Epub 2011 Jan 4.


Background/aims: Rat renal inner medullary collecting duct (IMCD) cells are physiologically exposed to a wide range of ambient tonicity. To maintain their function upon changes in osmolality, IMCD cells induce expression of osmoprotective and antiapoptotic genes, mainly mediated by the transcription factor Tonicity Enhancer Binding Protein (TonEBP). Some drugs like Cyclosporin-A (CsA) are discussed to interfere with the activity of TonEBP and thereby mediate their nephrotoxic effects. The aim of our study was to further understand CsA toxicity during elevation of ambient osmolality.

Methods: First we examined cytotoxicity of CsA in IMCD exposed to elevated tonicity. Employing microarray analysis of gene expression, real-time PCR and immunoassays, we scrutinized pathways contributing to this effect.

Results: We show that in IMCD cells CsA but not FK506 increases apoptosis upon an increase in tonicity. This effect is independent of cellular TonEBP localization or activity and reactive oxygen species. Microarray studies revealed marked quantitative differences in gene expression. Functional analysis showed overrepresentation of genes associated with cell death in presence of CsA. This correlated with increased mRNA expression of genes associated with the death receptor pathway and detection of TNFα in culture medium of cells treated with CsA.

Conclusion: Our results show that CsA cytotoxicity is induced under elevated ambient osmolality and that death receptor signaling probably contributes to CsA cytotoxicity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis*
  • Cells, Cultured
  • Cyclosporine / toxicity*
  • Female
  • Gene Expression Regulation
  • Immunosuppressive Agents / toxicity*
  • Kidney Tubules, Collecting / cytology*
  • Kidney Tubules, Collecting / drug effects
  • NFATC Transcription Factors / genetics
  • NFATC Transcription Factors / metabolism
  • NFATC Transcription Factors / physiology
  • Osmolar Concentration
  • Rats
  • Rats, Wistar
  • Reactive Oxygen Species / metabolism
  • Receptors, Death Domain / metabolism
  • Tacrolimus / toxicity
  • Tumor Necrosis Factor-alpha / metabolism


  • Immunosuppressive Agents
  • NFATC Transcription Factors
  • Reactive Oxygen Species
  • Receptors, Death Domain
  • Tumor Necrosis Factor-alpha
  • Cyclosporine
  • Tacrolimus