Hydrogen decreases athero-susceptibility in apolipoprotein B-containing lipoproteins and aorta of apolipoprotein E knockout mice

Atherosclerosis. 2012 Mar;221(1):55-65. doi: 10.1016/j.atherosclerosis.2011.11.043. Epub 2011 Dec 13.

Abstract

Objective: It is to characterize the underlying molecular mechanisms of the anti-atherosclerotic effects of hydrogen (dihydrogen; H(2)), a novel antioxidant. In particular, to examine the effects of hydrogen on athero-susceptibility in lipoproteins and aorta of apolipoprotein E knockout (apoE-/-) mice.

Methods and results: Plasma analysis by enzymatic method and spectrophotometric measurement showed that eight weeks intraperitoneally injection of hydrogen-saturated saline remarkably decreased plasma total and non-high-density lipoprotein (non-HDL) cholesterol, and malondialdehyde in apoE-/- mice fed either chow or high fat diet. Western blot analysis showed hydrogen treatment reduced the contents of apolipoprotein B (apoB), a major protein constituent of non-HDL in either plasma or hepatic tissues. Moreover, ELISA assay revealed that the production of tumor necrosis factor-α and interleukin-6 were significantly suppressed by hydrogen in RAW264.7 macrophages, after stimulation with the isolated non-HDL from treated or untreated mice. Immunohistochemistry of aortic valve sections revealed that hydrogen suppressed the expression of several proinflammatory factors and decreased vessel wall infiltration of macrophages. Besides, real-time PCR and Western blot analysis disclosed that hepatic scavenger receptor class B type I (SR-BI), ATP-binding cassette (ABC) transporters ABCG8, ABCB4, ABCB11, and macrophage SR-BI, were all induced by hydrogen treatment. Finally arterial wall lipid disposition displayed by oil red O staining was reduced significantly in aortic root and whole aorta en face in hydrogen administrated mice. In addition, hydrogen significantly improved HDL functionality in C57BL/6J mice assessed in two independent ways, namely (i) stimulation of cholesterol efflux from macrophage foam cells by measuring HDL-induced [(3)H]cholesterol efflux, and (ii) protection against LDL oxidation as a measure of Cu(2+)-induced TBARS formation.

Conclusion: These results reveal that administration of hydrogen-saturated saline decreases athero-susceptibility in apoB-containing lipoprotein and aortic atherosclerosis in apoE-/- mice and improves HDL functionality in C57BL/6J mice.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters / genetics
  • ATP-Binding Cassette Transporters / metabolism
  • Animals
  • Antioxidants / metabolism
  • Aorta / drug effects*
  • Aorta / metabolism
  • Aorta / pathology
  • Aortic Diseases / blood
  • Aortic Diseases / genetics
  • Aortic Diseases / pathology
  • Aortic Diseases / prevention & control*
  • Apolipoproteins B / blood
  • Apolipoproteins B / metabolism*
  • Apolipoproteins E / deficiency*
  • Apolipoproteins E / genetics
  • Atherosclerosis / blood
  • Atherosclerosis / genetics
  • Atherosclerosis / pathology
  • Atherosclerosis / prevention & control*
  • Blotting, Western
  • Cholesterol / blood
  • Diet, High-Fat
  • Disease Models, Animal
  • Enzyme-Linked Immunosorbent Assay
  • Gene Expression Regulation / drug effects
  • Hydrogen / administration & dosage*
  • Hydrogen / metabolism
  • Immunohistochemistry
  • Inflammation Mediators / blood
  • Injections, Intraperitoneal
  • Lipoproteins, HDL / blood
  • Liver / drug effects
  • Liver / metabolism
  • Macrophages / drug effects
  • Macrophages / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Oxidation-Reduction
  • Real-Time Polymerase Chain Reaction
  • Scavenger Receptors, Class B / genetics
  • Scavenger Receptors, Class B / metabolism
  • Sodium Chloride / administration & dosage*
  • Sodium Chloride / metabolism
  • Spectrophotometry

Substances

  • ATP-Binding Cassette Transporters
  • Antioxidants
  • Apob protein, mouse
  • Apolipoproteins B
  • Apolipoproteins E
  • Inflammation Mediators
  • Lipoproteins, HDL
  • Scarb1 protein, mouse
  • Scavenger Receptors, Class B
  • Sodium Chloride
  • Hydrogen
  • Cholesterol