title: Comparison of brown and white adipose tissue fat fractions in ob, seipin, and Fsp27 gene knockout mice by chemical shift-selective imaging and (1)H-MR spectroscopy.
abstract: Brown adipose tissue (BAT) plays a key role in thermogenesis to protect the body from cold and obesity. White adipose tissue (WAT) stores excess energy in the form of triglycerides. To better understand the genetic effect on regulation of WAT and BAT, we investigated the fat fraction (FF) in two types of adipose tissues in ob/ob, human BSCL2/seipin gene knockout (SKO), Fsp27 gene knockout (Fsp27(-/-)), and wild-type (WT) mice in vivo using chemical shift selective imaging and (1)H-MR spectroscopy. We reported that the visceral fat volume in WAT was significantly larger in ob/ob mice, but visceral fat volumes were lower in SKO and Fsp27(-/-) mice compared with WT mice. BAT FF was significantly higher in ob/ob mice than the WT group and similar to that of WAT. In contrast, WAT FFs in SKO and Fsp27(-/-) mice were lower and similar to that of BAT. The adipocyte size of WAT in ob/ob mice and the BAT adipocyte size in ob/ob, SKO, and Fsp27 mice were significantly larger compared with WT mice. However, the WAT adipocyte size was significantly smaller in SKO mice than in WT mice. Positive correlations were observed between the adipocyte size and FFs of WAT and BAT. These results suggested that smaller adipocyte size correlates with lower FFs of WAT and BAT. In addition, the differences in FFs in WAT and BAT measured by MR methods in different mouse models were related to the different regulation effects of ob, seipin, or Fsp27 gene on developing WAT and BAT.
authors.affiliation: Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, China.
authors.forename: Xin-Gui
authors.initials: XG
authors.lastname: Peng
authors.forename: Shenghong
authors.initials: S
authors.lastname: Ju
authors.forename: Fang
authors.initials: F
authors.lastname: Fang
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Ke
authors.initials: K
authors.lastname: Fang
authors.forename: Xin
authors.initials: X
authors.lastname: Cui
authors.forename: George
authors.initials: G
authors.lastname: Liu
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.forename: Hui
authors.initials: H
authors.lastname: Mao
authors.forename: Gao-Jun
authors.initials: GJ
authors.lastname: Teng
mesh_terms: D002001:Adipose Tissue, Brown / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D052436:Adipose Tissue, White / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D000818:Animals; D050218:Body Fat Distribution / Q000379:methods; D044388:GTP-Binding Protein gamma Subunits; D020962:Heterotrimeric GTP-Binding Proteins / Q000235:genetics*; D020738:Leptin / Q000235:genetics*; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008820:Mice, Obese; D011506:Proteins / Q000235:genetics*; D011522:Protons; D011859:Radiography
chemical_list: C115783:Bscl2 protein, mouse; D044388:GTP-Binding Protein gamma Subunits; D020738:Leptin; D011506:Proteins; D011522:Protons; C525805:fat-specific protein 27, mouse; D020962:Heterotrimeric GTP-Binding Proteins