Resveratrol attenuates oxidized LDL-evoked Lox-1 signaling and consequently protects against apoptotic insults to cerebrovascular endothelial cells

J Cereb Blood Flow Metab. 2011 Mar;31(3):842-54. doi: 10.1038/jcbfm.2010.180. Epub 2010 Oct 13.

Abstract

Cerebrovascular endothelial cells (CECs) are crucial components of the blood-brain barrier. Our previous study showed that oxidized low-density lipoprotein (oxLDL) induces apoptosis of CECs. This study was designed to further evaluate the effects of resveratrol on oxLDL-induced CEC insults and its possible molecular mechanisms. Resveratrol decreased the oxidation of LDL into oxLDL. Additionally, the oxLDL-caused oxidative stress and cell damage were attenuated by resveratrol. Exposure of CECs to oxLDL induced cell shrinkage, DNA fragmentation, and cell apoptosis, but resveratrol defended against such injuries. Application of Lox-1 small interference (si)RNA into CECs reduced the translation of this membrane receptor, and simultaneously increased resveratrol protection from oxLDL-induced cell apoptosis. By comparison, overexpression of Lox-1 attenuated resveratrol protection. Resveratrol inhibited oxLDL-induced Lox-1 mRNA and protein expressions. Both resveratrol and Lox-1 siRNA decreased oxLDL-enhanced translocation of proapoptotic Bcl-2-associated X protein (Bax) from the cytoplasm to mitochondria. Sequentially, oxLDL-induced alterations in the mitochondrial membrane potential, cytochrome c release, and activities of caspases-9, -3, and -6 were decreased by resveratrol. Pretreatment with Z-VEID-FMK (benzyloxycarbonyl-Leu-Glu-His-Asp-fluoromethyl ketone) synergistically promoted resveratrol's protection against DNA fragmentation and cell apoptosis. Therefore, this study shows that resveratrol can protect CECs from oxLDL-induced apoptotic insults via downregulating Lox-1-mediated activation of the Bax-mitochondria-cytochrome c-caspase protease pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antioxidants / pharmacology*
  • Apoptosis / drug effects*
  • Caspases / metabolism
  • Cell Survival / drug effects
  • Cells, Cultured
  • Cerebrovascular Circulation*
  • Cytochromes c / metabolism
  • Cytoprotection
  • Down-Regulation
  • Endothelial Cells / drug effects
  • Endothelial Cells / physiology*
  • Lipoproteins, LDL / antagonists & inhibitors
  • Lipoproteins, LDL / pharmacology*
  • Membrane Potentials / drug effects
  • Mice
  • Mitochondria / physiology
  • Peptide Hydrolases / metabolism
  • RNA, Messenger / antagonists & inhibitors
  • RNA, Messenger / drug effects
  • RNA, Small Interfering / pharmacology
  • Reactive Oxygen Species / antagonists & inhibitors
  • Receptors, Cell Surface / metabolism
  • Resveratrol
  • Scavenger Receptors, Class E / antagonists & inhibitors
  • Scavenger Receptors, Class E / genetics
  • Scavenger Receptors, Class E / metabolism*
  • Signal Transduction / drug effects*
  • Stilbenes / pharmacology*
  • Tissue Distribution / drug effects
  • bcl-2-Associated X Protein / metabolism

Substances

  • Antioxidants
  • Lipoproteins, LDL
  • Olr1 protein, mouse
  • RNA, Messenger
  • RNA, Small Interfering
  • Reactive Oxygen Species
  • Receptors, Cell Surface
  • Scavenger Receptors, Class E
  • Stilbenes
  • bcl-2-Associated X Protein
  • oxidized low density lipoprotein
  • Cytochromes c
  • Peptide Hydrolases
  • Caspases
  • Resveratrol