title: Hepatobiliary membrane transporters involving in the formation of cholesterol calculus.
abstract: BACKGROUND
  Cholecyst cholesterol lithiasis is a common disease of the digestive system; however, the cause of lithogenesis is still unclear. Although bile salt export pump (BSEP), multidrug resistance protein 2 (MRP2), and multiple drug resistance 3 (MDR3) are 3 well-known transporting proteins, their effect on lithogenesis has not been elucidated. This study was undertaken to examine the relationship between BSEP, MRP2, MDR3, and cholesterol calculus formation.
  
  
  METHODS
  Liver tissue specimens were taken from 20 patients with cholesterol calculus and from 10 patients with normal liver. mRNA and protein expressions of BSEP, MRP2, and MDR3 were determined by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot, respectively. This study was approved by the ethics committee of China Medical University and informed consent was obtained from all patients.
  
  
  RESULTS
  mRNA and protein expressions of BSEP, MRP2, and MDR3 were significantly down-regulated in the liver tissue of the patients with cholesterol calculus compared with normal liver tissue of the controls.
  
  
  CONCLUSIONS
  The down-regulation of BSEP, MRP2, and MDR3 may be correlated with the formation of cholesterol calculus.
authors.affiliation: Department of General Surgery, First Affiliated Hospital, China Medical University, Shenyang 110001, China. kong_fanmin@yahoo.com.cn
authors.forename: Fan-Min
authors.initials: FM
authors.lastname: Kong
authors.forename: Chun-Yang
authors.initials: CY
authors.lastname: Sui
authors.forename: Yu-Ji
authors.initials: YJ
authors.lastname: Li
authors.forename: Ke-Jian
authors.initials: KJ
authors.lastname: Guo
authors.forename: Ren-Xuan
authors.initials: RX
authors.lastname: Guo
mesh_terms: D000328:Adult; D001483:Base Sequence; D016022:Case-Control Studies; D002769:Cholelithiasis / Q000175:diagnosis* / Q000235:genetics; D002784:Cholesterol / Q000737:chemistry*; D015536:Down-Regulation; D005260:Female; D042882:Gallstones / Q000737:chemistry* / Q000378:metabolism; D005786:Gene Expression Regulation; D005819:Genetic Markers / Q000235:genetics; D006801:Humans; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D008969:Molecular Sequence Data; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism; D011336:Probability; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors; D012680:Sensitivity and Specificity
chemical_list: D002784:Cholesterol; D005819:Genetic Markers; D026901:Membrane Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D012333:RNA, Messenger