title: ITIH-5 expression in human adipose tissue is increased in obesity.
abstract: Adipocytes secrete many proteins that regulate metabolic functions. The gene inter-α (globulin) inhibitor H5 (ITIH-5) encodes a secreted protein and is known to be expressed abundantly in the placenta. However, using gene expression profiles data we observed high expression of ITIH-5 in adipose tissue. The aim of this study was to test the hypothesis that ITIH-5 is strongly expressed in human adipocytes and adipose tissue, and is related to obesity and clinical metabolic variables. ITIH-5 adipose tissue mRNA expression was analyzed with DNA microarray and real-time PCR, and its association with clinical variables was examined. ITIH-5 protein expression was analyzed using western blot. ITIH-5 mRNA expression was abundant in human adipose tissue, adipocytes, and placenta, and higher in subcutaneous (sc) compared to omental adipose tissue (P < 0.0001). ITIH-5 mRNA and protein expression in sc adipose tissue were higher in obese compared to lean subjects (P < 0.0001 and P < 0.001, respectively). ITIH-5 mRNA expression was reduced after diet-induced weight loss (P < 0.0001). ITIH-5 mRNA expression was associated with anthropometry and clinical metabolic variables. In conclusion, ITIH-5 is highly expressed in sc adipose tissue, increased in obesity, down regulated after weight loss, and associated with measures of body size and metabolism. Together, this indicates that ITIH-5 merits further investigation as a regulator of human metabolism.
authors.affiliation: Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: Åsa
authors.initials: Å
authors.lastname: Anveden
authors.forename: Kajsa
authors.initials: K
authors.lastname: Sjöholm
authors.forename: Peter
authors.initials: P
authors.lastname: Jacobson
authors.forename: Vilborg
authors.initials: V
authors.lastname: Palsdottir
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Walley
authors.forename: Philippe
authors.initials: P
authors.lastname: Froguel
authors.forename: Nasser
authors.initials: N
authors.lastname: Al-Daghri
authors.forename: Philip G
authors.initials: PG
authors.lastname: McTernan
authors.forename: Niklas
authors.initials: N
authors.lastname: Mejhert
authors.forename: Peter
authors.initials: P
authors.lastname: Arner
authors.forename: Lars
authors.initials: L
authors.lastname: Sjöström
authors.forename: Lena M S
authors.initials: LM
authors.lastname: Carlsson
authors.forename: Per-Arne
authors.initials: PA
authors.lastname: Svensson
mesh_terms: D017667:Adipocytes / Q000378:metabolism*; D000328:Adult; D015153:Blotting, Western; D015992:Body Mass Index; D002478:Cells, Cultured; D004038:Diet, Reducing; D015536:Down-Regulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D053491:Proteinase Inhibitory Proteins, Secretory / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D050151:Subcutaneous Fat / Q000378:metabolism* / Q000473:pathology; D015431:Weight Loss
chemical_list: C482680:ITIH5 protein, human; D053491:Proteinase Inhibitory Proteins, Secretory; D012333:RNA, Messenger