title: ABCA1 mRNA expression and cholesterol outflow in U937 cells.
abstract: OBJECTIVE
  To investigate the oxidized low density lipoprotein (oxLDL) on U937 cell ATP-binding cassette transporter A1 (ABCA1) mRNA expression and cholesterol efflux situation.
  
  
  METHODS
  Human U937 cells were incubated with gradient concentrations of oxLDL (0, 25, 50, 75, 100, 125 mg/L), and then dyed by oil red O to estimate the content of intracelluar lipid and detect the expressing quantity of ABCA1 mRNA by Real-time Fluorescence quantitative PCR simultaneously. Calculating the cholesterol efflux rates by using the scintillation counter to detect the amount of H(3)-cholesterol in each well cell culture plate and medium.
  
  
  RESULTS
  Real-time Fluorescence quantitative PCR analysis showed that the expression levels of ABCA1 mRNA in monocytes were lower than basal line when not intervened with oxLDL, and increased drastically with oxLDL stimulation, significant difference compared with controls (P<0.01), and reached the highest level at oxLDL 50 mg/L, nevertheless, continuously increasing the concentration of oxLDL above 50 mg/L, the expression decreased. So is the outflowing rate of intracelluar lipid. Oil red O dyeing results also suggested that celluar lipid content was the highest when intervened with 125 mg/L oxLDL, and increased most obviously at 50 mg/L oxLDL. Cholesterol outflow result also demonstrated that cholesterol outflow rate related with the ABCA1 mRNA expressing quantity.
  
  
  CONCLUSIONS
  With the increase of intervening concentration of oxLDL on U937cells, the exprssion of ABCAl mRNA represented that rising before 50 mg/L oxLDL, and then decreasing, reaching the top point at 50 mg/L oxLDL. So was the change in the outflowing rate of intracelluar lipid.
authors.affiliation: Department of Geriatric Cardiology, The First Associated Hospital of Medical College of Xi'an Jiaotong University Shaan Xi 710061, Xi'an, China.
authors.forename: Xian-Ming
authors.initials: XM
authors.lastname: Su
authors.affiliation: Department of Geriatric Cardiology, The First Associated Hospital of Medical College of Xi'an Jiaotong University Shaan Xi 710061, Xi'an, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Department of Geriatric Cardiology, The First Associated Hospital of Medical College of Xi'an Jiaotong University Shaan Xi 710061, Xi'an, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Geriatric Cardiology, The First Associated Hospital of Medical College of Xi'an Jiaotong University Shaan Xi 710061, Xi'an, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
mesh_terms: D064286:ATP Binding Cassette Transporter 1 / Q000378:metabolism*; D050197:Atherosclerosis / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism*; D005487:Foam Cells / Q000378:metabolism*; D006801:Humans; D050356:Lipid Metabolism / Q000502:physiology; D008077:Lipoproteins, LDL / Q000378:metabolism / Q000494:pharmacology; D009000:Monocytes / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction; D020298:U937 Cells
chemical_list: C577836:ABCA1 protein, human; D064286:ATP Binding Cassette Transporter 1; D008077:Lipoproteins, LDL; D012333:RNA, Messenger; C099252:oxidized low density lipoprotein; D002784:Cholesterol
keywords: ATP-binding cassette transporter 1; U937 cells; atherosclerosis; cholesterol metabolism; oxidized low-density lipo-protein