Cyclosporin A prevents the hypoxic adaptation by activating hypoxia-inducible factor-1alpha Pro-564 hydroxylation.

Abstract

The mechanism by which hypoxia induces gene transcription involves the inhibition of hypoxia-inducible factor (HIF)-1alpha prolyl hydroxylase activity, which prevents von Hippel-Lindau (vHL)-dependent targeting of HIF-1alpha to the ubiquitin-proteasome pathway. HIF-1alpha is stabilized, translocates to the nucleus, interacts with hypoxia-responsive elements, and promotes the activation of target genes. This report shows that cyclosporin A (CsA) interferes with the hypoxic signaling cascade in C6 glioma cells. CsA inhibits hypoxia-dependent gene transcription in a reporter gene assay and prevents the hypoxic accumulation of HIF-1alpha. Addition of the 530-603 C-terminal oxygen-dependent degradation (ODD) domain of HIF-1alpha to the green fluorescent protein (GFP) destabilized the protein in an oxygen-dependent manner. CsA prevented the hypoxic stabilization of an ODD.GFP fusion protein. An assay for 2-oxoglutarate-dependent dioxygenases was developed using a light mitochondrial kidney fraction as a source of enzyme. It uses the capacity of specific peptides to stimulate the degradation of [(14)C]2-oxoglutarate. CsA stimulated the enzymatic activity in the presence of a peptide that mimicked the 557-576 sequence of HIF-1alpha. The enzyme promoted [(35)S]vHL binding to glutathione S-transferase (GST).ODD fusion protein. This association increased in the presence of CsA. CsA effects were not observed when the proline residue corresponding to Pro-564 in the HIF-1alpha sequence was replaced by a hydroxyproline or an alanine residue. Finally, CsA increased vHL-ODD interaction during hypoxia. We conclude that CsA destabilizes HIF-1alpha by promoting hydroxylation of Pro-564 in the ODD domain. Such a mechanism may prevent hypoxic adaptation during CsA-induced nephrotoxicity and contribute to the adverse effects of this drug.

• Authors: Gisela D'Angelo, Eric Duplan, Paul Vigne, Christian Frelin
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 278 Issue 17 Pg. 15406-11 (Apr 25 2003) ISSN: 0021-9258 [Print] United States
• PMID: 12586829 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Hypoxia-Inducible Factor 1, alpha Subunit
• Transcription Factors
• Cyclosporine
• Proline
• Procollagen-Proline Dioxygenase

Topics

• Adaptation, Physiological (drug effects, genetics)
• Animals
• Cyclosporine (pharmacology)
• Hydroxylation (drug effects)
• Hypoxia (genetics)
• Hypoxia-Inducible Factor 1, alpha Subunit
• Kidney (metabolism)
• Procollagen-Proline Dioxygenase (metabolism)
• Proline (metabolism)
• Rats
• Transcription Factors (metabolism)
• Transcription, Genetic (drug effects)