Epigallocatechin-gallate stimulates NF-E2-related factor and heme oxygenase-1 via caveolin-1 displacement

Yuanyuan Zheng, Andrew Morris, Manjula Sunkara, Joseph Layne, Michal Toborek, Bernhard Hennig

Research output: Contribution to journalArticle

39 Scopus citations

Abstract

Flavonoids, such as the tea catechin epigallocatechin-gallate (EGCG), can protect against atherosclerosis by decreasing vascular endothelial cell inflammation. Heme oxygenase-1 (HO-1) is an enzyme that plays an important role in vascular physiology, and its induction may provide protection against atherosclerosis. Heme oxygenase-1 can be compartmentalized in caveolae in endothelial cells. Caveolae are plasma microdomains important in vesicular transport and the regulation of signaling pathways associated with the pathology of vascular diseases. We hypothesize that caveolae play a role in the uptake and transport of EGCG and mechanisms associated with the anti-inflammatory properties of this flavonoid. To test this hypothesis, we explored the effect of EGCG on the induction of NF-E2-related factor (Nrf2) and HO-1 in endothelial cells with or without functional caveolae. Treatment with EGCG activated Nrf2 and increased HO-1 expression and cellular production of bilirubin. In addition, EGCG rapidly accumulated in caveolae, which was associated with caveolin-1 displacement from the plasma membrane towards the cytosol. Similar to EGCG treatment, silencing of caveolin-1 by siRNA technique also resulted in up-regulation of Nrf2, HO-1 and bilirubin production. These data suggest that EGCG-induced caveolin-1 displacement may reduce endothelial inflammation.

Original languageEnglish (US)
Pages (from-to)163-168
Number of pages6
JournalJournal of Nutritional Biochemistry
Volume23
Issue number2
DOIs
StatePublished - Feb 1 2012

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Keywords

  • Atherosclerosis
  • Caveolae
  • EGCG
  • Endothelial cells
  • Nrf2

ASJC Scopus subject areas

  • Biochemistry
  • Clinical Biochemistry
  • Molecular Biology
  • Endocrinology, Diabetes and Metabolism
  • Nutrition and Dietetics

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