Humanin is expressed in human vascular walls and has a cytoprotective effect against oxidized LDL-induced oxidative stress

Cardiovasc Res. 2010 Nov 1;88(2):360-6. doi: 10.1093/cvr/cvq191. Epub 2010 Jun 18.

Abstract

Aims: Humanin (HN) is a 24-amino acid peptide that has been shown to have an anti-apoptotic function against neuronal cell death caused by Alzheimer's disease. Increased oxidative stress, one of the major factors contributing to this cell death, also plays an important role in the inflammatory process of atherosclerosis. The current study was designed to test the hypothesis that HN is expressed in the human vascular wall and may protect against oxidative stress.

Methods and results: HN expression in the vascular wall was detected by immunostaining in the endothelial cell layer of human internal mammary arteries (n = 5), atherosclerotic coronary arteries (n = 17), and sections of the greater saphenous vein (n = 3). HN mRNA was expressed in the human aortic endothelial cells (HAECs). Cytoprotective effects of HN against oxidative stress were tested in vitro in HAECs. Pre-treatment with 0.1 µM HN reduced oxidized LDL (Ox-LDL)-induced (i) formation of reactive oxygen species by 50%, (ii) apoptosis by ∼50% as determined by TUNEL staining, and (iii) formation of ceramide, a lipid second messenger involved in the apoptosis signalling cascade, by ∼20%.

Conclusion: The current study demonstrates for the first time the expression of HN in the endothelial cell layer of human blood vessels. Exogenous addition of HN to endothelial cell cultures was shown to be effective against Ox-LDL-induced apoptosis. These findings suggest that HN may play a role and may have a protective effect in early atherosclerosis in humans.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Apoptosis
  • Cells, Cultured
  • Ceramides / metabolism
  • Coronary Artery Disease / metabolism
  • Coronary Artery Disease / pathology
  • Coronary Vessels / metabolism
  • Coronary Vessels / pathology
  • Cytoprotection
  • Endothelial Cells / metabolism*
  • Endothelial Cells / pathology
  • Humans
  • Immunohistochemistry
  • In Situ Nick-End Labeling
  • Intracellular Signaling Peptides and Proteins / blood
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Lipoproteins, LDL / metabolism*
  • Mammary Arteries / metabolism
  • Mammary Arteries / pathology
  • Middle Aged
  • Oxidative Stress*
  • RNA, Messenger / metabolism
  • Reactive Oxygen Species / metabolism
  • Saphenous Vein / metabolism
  • Saphenous Vein / pathology

Substances

  • Ceramides
  • Intracellular Signaling Peptides and Proteins
  • Lipoproteins, LDL
  • RNA, Messenger
  • Reactive Oxygen Species
  • humanin
  • oxidized low density lipoprotein