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

Academic Article

Abstract

  • 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.
  • Published In

  • Atherosclerosis  Journal
  • Keywords

  • Animals, Apolipoproteins E, Atherosclerosis, Cholesterol, Female, Hep G2 Cells, Hepatocytes, Humans, Lipoproteins, Macrophages, Mice, Peptide Fragments, Peptides, Reactive Oxygen Species, Receptors, LDL
  • Digital Object Identifier (doi)

    Authorlist

  • Handattu SP; Nayyar G; Garber DW; Palgunachari MN; Monroe CE; Keenum TD; Mishra VK; Datta G; Anantharamaiah GM
  • Start Page

  • 58
  • End Page

  • 64
  • Volume

  • 227
  • Issue

  • 1