title: Visualization and Quantification of Browning Using a Ucp1-2A-Luciferase Knock-in Mouse Model.
abstract: Both mammals and adult humans possess classic brown adipocytes and beige adipocytes, and the amount and activity of these adipocytes are considered key factors in combating obesity and its associated metabolic diseases. Uncoupling protein 1 (Ucp1) is the functional marker of both brown and beige adipocytes. To facilitate a reliable, easy, and sensitive measurement of Ucp1 expression both in vivo and in vitro, we generated a Ucp1-2A-luciferase knock-in mouse by deleting the stop codon for the mouse Ucp1 gene and replacing it with a 2A peptide. This peptide was followed by the luciferase coding sequence to recapitulate the expression of the Ucp1 gene at the transcriptional and translational levels. With this mouse, we discovered a cold-sensitive brown/beige adipose depot underneath the skin of the ears, which we named uBAT. Because of the sensitivity and high dynamic range of luciferase activity, the Ucp1-2A-luciferase mouse is useful for both in vitro quantitative determination and in vivo visualization of nonshivering thermogenesis. With the use of this model, we identified and characterized axitinib, an oral small-molecule tyrosine kinase inhibitor, as an effective browning agent.
authors.affiliation: CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Medical University, and Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Liufeng
authors.initials: L
authors.lastname: Mao
authors.affiliation: Gladstone Institute of Cardiovascular Disease, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA.
authors.forename: Baoming
authors.initials: B
authors.lastname: Nie
authors.affiliation: CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Medical University, and Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Nie
authors.affiliation: Department of Medicine, The University of Hong Kong, Hong Kong.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Hui
authors.affiliation: Wellcome Sanger Institute, Cambridge, U.K.
authors.forename: Xuefei
authors.initials: X
authors.lastname: Gao
authors.affiliation: Research & Development Center, Infinitus (China) Company Ltd., Guangzhou, China.
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Lin
authors.affiliation: Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.affiliation: CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Medical University, and Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Xu
authors.affiliation: CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Medical University, and Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Tang
authors.affiliation: CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Medical University, and Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Yuan
authors.affiliation: CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Medical University, and Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Kuai
authors.initials: K
authors.lastname: Li
authors.affiliation: CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Medical University, and Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.affiliation: CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Medical University, and Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Ding
authors.affiliation: CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Medical University, and Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.|Department of Medicine, The University of Hong Kong, Hong Kong.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Medical University, and Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.|Department of Medicine, The University of Hong Kong, Hong Kong.
authors.forename: Aimin
authors.initials: A
authors.lastname: Xu
authors.affiliation: Shanghai Nan Fang Model Organism Research Center, Shanghai, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Fei
authors.affiliation: Singapore Bioimaging Consortium and Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore.
authors.forename: Weiping
authors.initials: W
authors.lastname: Han
authors.affiliation: Wellcome Sanger Institute, Cambridge, U.K.
authors.forename: Pentao
authors.initials: P
authors.lastname: Liu
authors.affiliation: National Institute of Nutrition and Seafood Research, Bergen, Norway.|Laboratory of Genomics and Molecular Biomedicine, Department of Biology, University of Copenhagen, Copenhagen, Denmark.|Beijing Genomics Institute-Shenzhen, Shenzhen, China.
authors.forename: Lise
authors.initials: L
authors.lastname: Madsen
authors.affiliation: Laboratory of Genomics and Molecular Biomedicine, Department of Biology, University of Copenhagen, Copenhagen, Denmark.|Beijing Genomics Institute-Shenzhen, Shenzhen, China.
authors.forename: Karsten
authors.initials: K
authors.lastname: Kristiansen
authors.affiliation: Diabetes Center, The Second Xiangya Hospital, Institute of Metabolism and Endocrinology, Central South University, Changsha, China.
authors.forename: Zhiguang
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Gladstone Institute of Cardiovascular Disease, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA wu_donghai@gibh.ac.cn sheng.ding@gladstone.ucsf.edu.
authors.forename: Sheng
authors.initials: S
authors.lastname: Ding
authors.affiliation: CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Medical University, and Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China wu_donghai@gibh.ac.cn sheng.ding@gladstone.ucsf.edu.|Joint School of Biological Sciences, Guangzhou Institute of Biomedicine and Health, Guangzhou Medical University, Guangzhou, China.
authors.forename: Donghai
authors.initials: D
authors.lastname: Wu
mesh_terms: D000069797:Adipocytes, Beige / Q000187:drug effects / Q000378:metabolism*; D052437:Adipocytes, Brown / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D000077784:Axitinib; D015153:Blotting, Western; D004423:Ear; D055879:Gene Knock-In Techniques; D005951:Glucose Tolerance Test; D007093:Imidazoles / Q000494:pharmacology; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007191:Indazoles / Q000494:pharmacology; D008156:Luciferases / Q000235:genetics; D008163:Luminescent Measurements; D008297:Male; D051379:Mice; D023421:Models, Animal; D010101:Oxygen Consumption; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050151:Subcutaneous Fat / Q000187:drug effects / Q000378:metabolism*; D022722:Thermogenesis / Q000187:drug effects; D000071256:Uncoupling Protein 1 / Q000235:genetics
chemical_list: D007093:Imidazoles; D007191:Indazoles; D047428:Protein Kinase Inhibitors; C000604372:Ucp1 protein, mouse; D000071256:Uncoupling Protein 1; D000077784:Axitinib; D008156:Luciferases