Two apolipoprotein E mimetic peptides with similar cholesterol reducing properties exhibit differential atheroprotective effects in LDL-R null mice

Atherosclerosis. 2013 Mar;227(1):58-64. doi: 10.1016/j.atherosclerosis.2012.10.064. Epub 2012 Nov 2.


Objective: We investigated two apoE mimetic peptides with similar long-term plasma cholesterol reducing abilities for their effects on atherosclerotic lesions in Western diet-fed female LDL-receptor (LDL-R) null mice.

Methods and results: Single doses of peptides Ac-hE18A-NH(2) and mR18L were administered retro-orbitally to LDL-R null mice on Western diet and plasma cholesterol was measured at 10 min, 4 h, and 24 h post administration. Peptide mR18L and not Ac-hE18A-NH(2) reduced plasma cholesterol levels significantly at 4 h post administration. However, multiple administrations (100 μg/mouse twice weekly for 8 weeks) resulted in a similar reduction in plasma cholesterol. Only the plasma from the Ac-hE18A-NH(2) group had significantly reduced reactive oxygen species levels at the end of the treatment protocol. Both mR18L and Ac-hE18A-NH(2) showed reduced atherosclerotic lesion areas. However, peptide Ac-hE18A-NH(2) was significantly more effective in inhibiting atherosclerosis. Both peptides reduced total plaque macrophage load compared to the saline treated animals, with peptide Ac-hE18A-NH(2) having a greater reduction. Incubation of HepG2 cells and THP-1 monocyte-derived macrophages with both peptides in the presence of oxidized phospholipid showed that Ac-hE18A-NH(2) promotes the secretion of apoE from the cells whereas mR18L does not.

Conclusions: Despite similar reductions in plasma cholesterol levels, Ac-hE18A-NH(2) was more effective in inhibiting lesions than mR18L, possibly due to its ability to promote the secretion of apoE from hepatocytes and macrophages.

Publication types

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

MeSH terms

  • Animals
  • Apolipoproteins E / chemistry
  • Apolipoproteins E / metabolism*
  • Atherosclerosis / prevention & control*
  • Cholesterol / blood
  • Female
  • Hep G2 Cells
  • Hepatocytes / drug effects
  • Hepatocytes / metabolism
  • Humans
  • Lipoproteins / pharmacology*
  • Macrophages / drug effects
  • Macrophages / metabolism
  • Mice
  • Peptide Fragments / pharmacology*
  • Peptides / pharmacology*
  • Reactive Oxygen Species / blood
  • Receptors, LDL / genetics*


  • Ac-hE18A-NH(2)
  • Apolipoproteins E
  • Lipoproteins
  • Peptide Fragments
  • Peptides
  • Reactive Oxygen Species
  • Receptors, LDL
  • mR18L peptide
  • Cholesterol