title: [Effect of apolipoprotein A-I mimetic peptides on cholesterol efflux in RAW264.7 cells].
abstract: OBJECTIVE
  To determine the effect and possible mechanism of an apolipoprotein (apo) A-I mimetic peptide, D-4F, on cholesterol efflux in RAW264.7 macrophages.
  
  
  METHODS
  RAW264.7 macrophages were incubated in the medium containing 8-bromo cAMP (8-Br-cAMP, 0.5 mmol/L) and ox-LDL (50 μg/mL) for 24 h. Then various concentrations of D-4F (0-100 μg/mL) or H89 (20 μmol/L, a protein kinase A inhibitor) were added for the purpose of interference. The intracellular cyclic AMP (cAMP) level was determined by enzyme-linked immunoabsobant assay (ELISA). ATP binding cassette transporter A1 (ABCA1) expression in the macrophages was quantitated by real-time PCR and Western blot.
  
  
  RESULTS
  D-4F significantly increased the cholesterol efflux in both concentration and time-dependent manner accompanied by the increase in the intracellular cAMP level, ABCA1 mRNA and protein expression. The effect of D-4F on cholesterol efflux ABCA1 expression was enhanced by 8-Br-cAMP. Although H89 did not affect the basal cholesterol efflux and ABCA1 expression, it could attenuate the effect of 8-Br cAMP.
  
  
  CONCLUSIONS
  D-4F affects cholesterol efflux, cAMP level, and ABCA1 expression in macrophages, which is likely involved in the pathway of cAMP/PKA/ABCA1.
authors.affiliation: Department of Cardiology, Central South University, Changsha 410011, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Xie
authors.forename: Shuiping
authors.initials: S
authors.lastname: Zhao
mesh_terms: D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D016632:Apolipoprotein A-I / Q000737:chemistry / Q000494:pharmacology*; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D032701:Biomimetics; D002460:Cell Line; D002784:Cholesterol / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D006801:Humans; D008264:Macrophages / Q000166:cytology / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*
chemical_list: C577836:ABCA1 protein, human; D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters; D016632:Apolipoprotein A-I; D010455:Peptides; D002784:Cholesterol; D000242:Cyclic AMP