title: Downregulation of Max dimerization protein 3 is involved in decreased visceral adipose tissue by inhibiting adipocyte differentiation in zebrafish and mice.
abstract: BACKGROUND
  The diet-induced obesity model of zebrafish (DIO-zebrafish) share a common pathophysiological pathway with mammalian obesity.
  
  
  OBJECTIVE
  We aimed to investigate the role of Max dimerization protein 3 (MXD3) in visceral fat accumulation and adipocyte differentiation, by conducting knockdown experiments using zebrafish and mouse preadipocytes.
  
  
  METHODS
  To identify genes related to visceral adiposity, we conducted transcriptome analyses of human and zebrafish obese populations using the Gene Expression Omnibus and DNA microarray. We then intraperitoneally injected morpholino antisense oligonucleotides (MO-mxd3) to knockdown mxd3 gene expression in DIO-zebrafish and measured several parameters, which reflected human obesity and associated metabolic diseases. Finally, lentiviral Mxd3 shRNA knockdown in mouse 3T3-L1 preadipocytes was conducted. Quantitative PCR analyses of several differentiation markers were conducted during these gene knockdown experiments.
  
  
  RESULTS
  We found that MXD3 expression was increased in the obese population in humans and zebrafish. Intraperitoneal MO-mxd3 administration to DIO-zebrafish suppressed the increase in body weight, visceral fat accumulation and the size of mature adipocytes. Subsequently, dyslipidemia and liver steatosis were also ameliorated by MO-mxd3. In mouse adipocytes, Mxd3 expression was drastically increased in the early differentiation stage. Mxd3 shRNA inhibited preadipocyte proliferation and adipocyte maturation. Quantitative PCR analyses showed that the early differentiation marker, CCAAT/enhancer-binding protein delta (Cebpd) and late differentiation markers (CCAAT/enhancer-binding protein, alpha and peroxisome proliferator-activated receptor gamma) were downregulated by Mxd3 knockdown in 3T3-L1 cells and DIO-zebrafish. Subsequently, mature adipocyte markers (adiponectin and caveolin 1 for zebrafish, and fatty acid binding protein 4 and stearoyl-coenzyme A desaturase 1 for mouse adipocytes) were also decreased.
  
  
  CONCLUSIONS
  Mxd3 regulates preadipocyte proliferation and early adipocyte differentiation via Cebpd downregulation in vitro and in vivo. Integrated analysis of human and zebrafish transcriptomes allows identification of a novel therapeutic target against human obesity and further associated metabolic disease.
authors.affiliation: 1] Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine, Mie, Japan [2] Department of Systems Pharmacology, Mie University Graduate School of Medicine, Mie, Japan [3] Mie University Medical Zebrafish Research Center, Mie, Japan [4] Department of Bioinformatics, Mie University Life Science Research Center, Mie, Japan [5] Department of Omics Medicine, Mie University Industrial Technology Innovation, Mie, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Shimada
authors.affiliation: Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine, Mie, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Kuroyanagi
authors.affiliation: Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine, Mie, Japan.
authors.forename: B
authors.initials: B
authors.lastname: Zhang
authors.affiliation: 1] Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine, Mie, Japan [2] Department of Systems Pharmacology, Mie University Graduate School of Medicine, Mie, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ariyoshi
authors.affiliation: 1] Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine, Mie, Japan [2] Department of Systems Pharmacology, Mie University Graduate School of Medicine, Mie, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Umemoto
authors.affiliation: 1] Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine, Mie, Japan [2] Department of Systems Pharmacology, Mie University Graduate School of Medicine, Mie, Japan [3] Mie University Medical Zebrafish Research Center, Mie, Japan [4] Department of Bioinformatics, Mie University Life Science Research Center, Mie, Japan [5] Department of Omics Medicine, Mie University Industrial Technology Innovation, Mie, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Nishimura
authors.affiliation: 1] Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine, Mie, Japan [2] Department of Systems Pharmacology, Mie University Graduate School of Medicine, Mie, Japan [3] Mie University Medical Zebrafish Research Center, Mie, Japan [4] Department of Bioinformatics, Mie University Life Science Research Center, Mie, Japan [5] Department of Omics Medicine, Mie University Industrial Technology Innovation, Mie, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation; D019281:Dimerization; D015536:Down-Regulation; D055785:Gene Knockdown Techniques; D050152:Intra-Abdominal Fat / Q000378:metabolism*; D051379:Mice; D009765:Obesity / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D015027:Zebrafish
chemical_list: C472089:Mxd3 protein, mouse; D012097:Repressor Proteins