POPC/apoA-I discs as a potent lipoprotein modulator in Tangier disease

Atherosclerosis. 2008 Mar;197(1):283-9. doi: 10.1016/j.atherosclerosis.2007.04.025. Epub 2007 Jun 8.

Abstract

Tangier disease (TD) is a rare familial disorder with mutations in the ATP-binding cassette transporter A1 (ABCA1) gene. It results in extremely low levels of HDL cholesterol. Since TD is a genetic disorder, a therapeutic approach to TD has not been established. We report a typical case of TD with a homozygous novel point mutation in the ABCA1 gene by using genomic DNA sequencing. Primary monocyte-derived macrophages of blood from a patient with TD and normolipidemic subjects were compared for cholesterol efflux. The macrophages from the TD patient showed no apoA-I-mediated cholesterol efflux. In contrast, POPC/apoA-I discs were able to take up cholesterol from macrophages from both the TD and normolipidemic subject. Capillary isotachophoresis (cITP), which separates lipoprotein into subfractions according to electrophoretic mobility, was used to characterize plasma lipoprotein subfractions. Both slow-migrating HDL (sHDL) and slow-migrating LDL (sLDL; unmodified LDL) subfractions were extremely low in the patient with TD. After incubation of plasma from the TD patient with POPC/apoA-I discs, sHDL and sLDL subfractions rapidly appeared. In conclusion, POPC/apoA-I discs not only have beneficial effects on cholesterol efflux, but also have potential as a lipoprotein modulator in patients with TD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP Binding Cassette Transporter 1
  • ATP-Binding Cassette Transporters / genetics
  • Apolipoprotein A-I / pharmacology*
  • Apolipoproteins B / metabolism
  • Apolipoproteins E / metabolism
  • Cells, Cultured
  • Cholesterol Esters / metabolism
  • Cholesterol, HDL / deficiency
  • Cholesterol, HDL / metabolism
  • Electrophoresis
  • Humans
  • Macrophages / cytology
  • Macrophages / drug effects*
  • Macrophages / metabolism*
  • Phosphatidylcholines / pharmacology*
  • Tangier Disease / genetics
  • Tangier Disease / metabolism*
  • Triglycerides / metabolism

Substances

  • ABCA1 protein, human
  • ATP Binding Cassette Transporter 1
  • ATP-Binding Cassette Transporters
  • Apolipoprotein A-I
  • Apolipoproteins B
  • Apolipoproteins E
  • Cholesterol Esters
  • Cholesterol, HDL
  • Phosphatidylcholines
  • Triglycerides
  • 1-palmitoyl-2-oleoylphosphatidylcholine