title: MFAP5 is related to obesity-associated adipose tissue and extracellular matrix remodeling and inflammation.
abstract: OBJECTIVE
  Low-grade inflammation is involved in adipose tissue (AT) and extracellular matrix (ECM) remodeling and induces deposition of ECM proteins in AT. We have previously shown that MFAP5 (microfibrillar-associated protein 5) expression decreases in AT after weight loss. The aim of this study was to investigate MFAP5 localization in human AT and gene expression in adipocytes and the role of MFAP5 in adipocyte metabolism and inflammation.
  
  
  METHODS
  MFAP5 protein localization and gene expression were studied with immunohistochemistry and quantitative reverse transcriptase PCR (RT-qPCR) in human subcutaneous AT and cultured Simpson-Golabi-Behmel syndrome (SGBS) adipocytes, respectively. The effect of MFAP5 knock-down by siRNA on gene expression and insulin action was examined with RT-qPCR, western blot, and insulin-stimulated glucose uptake. The effect of different cytokines on MFAP5 gene and protein expression was investigated in cultured human SGBS preadipocytes.
  
  
  RESULTS
  MFAP5 protein was highly expressed in AT, and gene expression decreased during adipocyte differentiation in SGBS cells. Treatment of preadipocytes with TNFα and TGFβ1 increased MFAP5 gene and protein expression. Furthermore, MFAP5 knock-down decreased the expression of genes involved in inflammation.
  
  
  CONCLUSIONS
  Our results demonstrate that factors involving low-grade inflammation modulate MFAP5 expression and that the modified expression of MFAP5 may further regulate AT inflammation.
authors.affiliation: Department of Clinical Nutrition, University of Eastern Finland, Institute of Public Health and Clinical Nutrition, Kuopio, Finland.
authors.forename: Maija
authors.initials: M
authors.lastname: Vaittinen
authors.affiliation: Department of Clinical Nutrition, University of Eastern Finland, Institute of Public Health and Clinical Nutrition, Kuopio, Finland.
authors.forename: Marjukka
authors.initials: M
authors.lastname: Kolehmainen
authors.affiliation: Department of Medicine (H7), Karolinska Institute, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Rydén
authors.affiliation: Department of Surgery, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Eskelinen
authors.affiliation: Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, University of Ulm, Ulm, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Wabitsch
authors.affiliation: Department of Clinical Nutrition, University of Eastern Finland, Institute of Public Health and Clinical Nutrition, Kuopio, Finland.|Departments of Medicine and Clinical Nutrition, Obesity Center, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Jussi
authors.initials: J
authors.lastname: Pihlajamäki
authors.affiliation: Department of Clinical Nutrition, University of Eastern Finland, Institute of Public Health and Clinical Nutrition, Kuopio, Finland.|Research Unit, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Uusitupa
authors.affiliation: Department of Clinical Nutrition, University of Eastern Finland, Institute of Public Health and Clinical Nutrition, Kuopio, Finland.
authors.forename: Leena
authors.initials: L
authors.lastname: Pulkkinen
mesh_terms: D017667:Adipocytes / Q000378:metabolism; D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D000368:Aged; D002454:Cell Differentiation / Q000235:genetics; D002460:Cell Line; D003285:Contractile Proteins / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha
chemical_list: D003285:Contractile Proteins; D016207:Cytokines; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; C115627:MFAP5 protein, human; C439524:TNF protein, human; D014409:Tumor Necrosis Factor-alpha