title: Enhanced A-FABP expression in visceral fat: potential contributor to the progression of NASH.
abstract: OBJECTIVE
  Adipose tissue is an active endocrine organ that secretes various metabolically important substances including adipokines, which represent a link between insulin resistance and nonalcoholic steatohepatitis (NASH). The factors responsible for the progression from simple steatosis to steatohepatitis remain elusive, but adipokine imbalance may play a pivotal role. We evaluated the expressions of adipokines such as visfatin, adipocyte-fatty-acid-binding protein (A-FABP), and retinol-binding protein-4 (RBP-4) in serum and tissue. The aim was to discover whether these adipokines are potential predictors of NASH.
  
  
  METHODS
  Polymerase chain reaction, quantification of mRNA, and Western blots encoding A-FABP, RBP-4, and visfatin were used to study tissue samples from the liver, and visceral and subcutaneous adipose tissue. The tissue samples were from biopsy specimens obtained from patients with proven NASH who were undergoing laparoscopic cholecystectomy due to gallbladder polyps.
  
  
  RESULTS
  PATIENTS WERE CLASSIFIED INTO TWO GROUPS: NASH, n=10 and non-NASH, n=20 according to their nonalcoholic fatty liver disease Activity Score. Although serum A-FABP levels did not differ between the two groups, the expressions of A-FABP mRNA and protein in the visceral adipose tissue were significantly higher in NASH group than in non-NASH group (104.34 vs. 97.05, P<0.05, and 190.01 vs. 95.15, P<0.01, respectively). Furthermore, the A-FABP protein expression ratio between visceral adipose tissue and liver was higher in NASH group than in non-NASH group (4.38 vs. 1.64, P<0.05).
  
  
  CONCLUSIONS
  NASH patients had higher levels of A-FABP expression in their visceral fat compared to non-NASH patients. This differential A-FABP expression may predispose patients to the progressive form of NASH.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Min Yong
authors.initials: MY
authors.lastname: Yoon
authors.forename: Jun Mo
authors.initials: JM
authors.lastname: Sung
authors.forename: Chang Seok
authors.initials: CS
authors.lastname: Song
authors.forename: Won Young
authors.initials: WY
authors.lastname: Lee
authors.forename: Eun Jung
authors.initials: EJ
authors.lastname: Rhee
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Shin
authors.forename: Chang Hak
authors.initials: CH
authors.lastname: Yoo
authors.forename: Seoung Wan
authors.initials: SW
authors.lastname: Chae
authors.forename: Ja Yeon
authors.initials: JY
authors.lastname: Kim
authors.forename: Wook
authors.initials: W
authors.lastname: Jin
authors.forename: Yong Kyun
authors.initials: YK
authors.lastname: Cho
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D050556:Fatty Acid-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005234:Fatty Liver / Q000378:metabolism / Q000473:pathology*; D005786:Gene Expression Regulation; D006801:Humans; D050152:Intra-Abdominal Fat / Q000378:metabolism*; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D054409:Nicotinamide Phosphoribosyltransferase / Q000235:genetics / Q000378:metabolism; D065626:Non-alcoholic Fatty Liver Disease; D012333:RNA, Messenger / Q000378:metabolism; D054839:Retinol-Binding Proteins, Plasma / Q000235:genetics / Q000378:metabolism
chemical_list: C493410:FABP4 protein, human; D050556:Fatty Acid-Binding Proteins; C101326:RBP4 protein, human; D012333:RNA, Messenger; D054839:Retinol-Binding Proteins, Plasma; D054409:Nicotinamide Phosphoribosyltransferase
keywords: Adipocyte-fatty-acid-binding protein; NASH; PCR; Retinol-binding protein-4; Visfatin; Western blot